【Objective】 The aim of this study was to determine the influence of varying phosphorus concentrations and mycorrhizal fungi on Pinus massoniana container seedlings.【Method】A split-plot experimental design was adopted. The main plot was the mycorrhizal fungi treatment with two treatment levels: inoculation and non-inoculation. The inoculation treatment involved placing 0.3 g of solid preparation made of vermiculite and Lactarius deliciosus mycelium suspension under the planting hole during sowing. The sub-plot was the phosphorus addition treatment, which set a P-based water-soluble fertilizerof seven treatment levels. The amount of phosphorus added ranged between 50 and 600 g/m3. From July to October, water-soluble fertilizers of different gradients were dissolved in water for 15 times at equal intervals, and then evenly sprayed on the seedlings. Once this was done, growth was analyzed in relation to N and P uptake, the use of phosphorus and mycorrhizal fungi. 【Result】 After inoculation with mycorrhizal fungi, compared with the non-inoculation treatment, the average seedling height, caliper, total biomass and root diameter of 1-year-old P. massoniana container seedlings increased by 9.87%, 3.35%, 41.50% and 12.41%, respectively, whereas nutrient indices such as N and P uptake and utilization index increased by 5.05%, 25.03%, 100.36% and 70.53%, respectively. The height-to-diameter ratio, total root length, and N and P contents decreased by 5.98%, 22.47%, 24.97%, and 11.26%, respectively. There were significant differences in growth and nutrient traits, except for seedling height and N uptake, before and after inoculation. Along with the increase in P content, the caliper and P uptake of the whole plant increased before and after inoculation, the height-diameter ratio decreased, and the N and P content of the whole plant initially increased and then decreased. For the caliper, total biomass, root diameter, P uptake of the whole plant, and N and P utilization index of different P addition gradients, the values of the inoculated treatment were greater than those of the non-inoculated treatment. As for the height-diameter ratio, total root length, and P content of the whole plant, the non-inoculated values were greater than the inoculated values. Inoculation with mycorrhizal fungi and P addition had no significant interaction effect on the growth and nutrient traits of P. massoniana container seedlings. After inoculation, the growth traits of P. massoniana container seedlings were more sensitive to changes in N content in the whole plant, and the response to N and P uptake and utilization indices was further enhanced. 【Conclusion】 Inoculation of mycorrhizal fungi (L. deliciosus) can establish a good synergistic symbiotic relationship with container seedlings of P. massoniana, which not only promoted the growth of P. massoniana container seedlings but also improved the nutrient utilization efficiency of N and P. After inoculation, the height-diameter ratio of seedlings decreased, their utilization index of N and P increased, and the seedlings could experience normal growth and metabolism under low nutrient concentrations, which is vital for cultivating high-quality seedlings while reducing seedling cost.
【Objective】 The beetle (Monochamus alternatus) is an important wood borer in pine forests and it is also the most important vector of pine wood nematodes in Asia. The effects of temperature, sex and weight on the feeding ability and the bark thickness, trunk diameter, and weight on oviposition ability were analyzed regarding M. alternatus to provide a scientific guidance for controlling the beetles.【Method】 The beetles were collected from an insect cage with a weight in the range of 0.3 g≤M<0.6 g that was placed in the insect incubator to compare the feeding ability under four temperature conditions (25, 30, 35 and 40℃). Five female and five male adult beetles of the similar weight were selected and placed in an insect incubator to compare feeding between adult males and females. Beetles with different weights (M<0.3 g, 0.3 g≤M<0.6 g and M≥0.6 g) were placed in the insect incubator at the same temperature to compare feeding abilities with different weights. In order to study the effect of trunk diameter and bark thickness on the oviposition of beetles, pine trunks with different diameters (2.0 cm<D< 3.0 cm, 4.0 cm≤D<5.0 cm, and D≥6.0 cm) and trunks with different bark thicknesses (d=1, 4 and 9 mm) with beetles were placed separately into the insect barrel. The number of oviposition scars was counted. To compare the relationship between the oviposition ability and weight, the number of oviposition scars made by the beetles with different weights (M<0.3 g, 0.3 g≤M<0.6 g and M≥0.6 g) on the trunk was counted, and the abdomens were dissected to count the number of eggs inside.【Result】 The feeding ability of beetles at different temperatures order was as follows: 35, 40, 30, 25 ℃; however, there was no significant difference in feeding between male and female adults. The feeding ability of beetles with M≥0.6 g was the strongest, and that of beetles with M<0.3 g was the weakest. Among trunks with different diameters, beetles preferred to lay eggs on trunks with diameters of D≥6.0 cm, and the number of eggs laid on trunks with diameters of 2 cm<d<3 cm was the lowest. Among trunks with different bark thickness, beetles laid the most eggs on trunks with bark of d=1 mm and the least eggs on trunks with bark of d=9 mm. The oviposition ability of beetles with M≥0.6 g was significantly better than that of beetles with M<0.3 g and 0.3 g≤M<0.6 g. the number of eggs in the abdomen of beetles with M≥0.6 g was significantly more than that of those with other weights.【Conclusion】 The feeding ability of M. alternatus had no significant relationship with sex but was related to weight and temperature. Feeding capacity increased with beetle weight; the feeding ability of M. alternatus at 35 ℃ was higher than that at other temperatures. The oviposition of M. alternatus was related to the size, bark thickness, and trunk diameter. The oviposition ability of the beetles increased with weight, and they preferred to lay eggs on thinner barks and trunks with larger diameters.
【Objective】The Thousand-Island Lake basin is an important water conservation and ecological barrier area in the Yangtze River Delta. Thus, the study of water supply services is of great significance to ecological protection and high-quality sustainable development of the social economy. 【Method】The water yield of the Thousand-Island Lake basin was quantified over a six-year period: 1995, 2000, 2005, 2010, 2015 and 2019 based on the InVEST model, and water yield spatio-temporal variations and influencing factors were explored using the scenario and geodetector analyses.【Result】From 1995 to 2019, water yield inter-annual variations in the Thousand-Island Lake basin was consistent with precipitation trends; that is the water yield decreased significantly from 1995 to 2005, increased significantly from 2005 to 2015, and showed a subsequent marginal decrease from 2015 to 2019. Spatial distribution patterns showed little variation over the study period; however, patterns were high in the west of the basin and low in the basin’s eastern lake. The average water yield of buildings was higher than that of other land use types, followed by grasslands and woodland; water bodies had the lowest average water yield. Precipitation had a stronger effect on water yield than that of land use changes, which was significant. Actual evapotranspiration was the main driving factor of water spatial patterns, followed by land use types. The interaction between actual evapotranspiration and rainfall was the most significant than others. 【Conclusion】The water yield is the result of a combination of factors including climate and land use types. For the future ecological construction and environmental protection, the impact of terrain, climate, and human activities on water yield services must be considered and comprehensively studied.
【Objective】The purpose of this study was to investigate the soil nutrient and stoichiometry characteristics of different vegetation restoration modes in the context of Karst landscapes within the water source area of the South-to-North Water Diversion Project and to evaluate the soil nutrient supply status of woodland habitats at the northern edge of the contiguous southern Karst distribution area, with the aim of providing a theoretical basis for the forest management, restoration and reconstruction of degraded ecosystems, and rock desertification management in the water-supporting area of the South-to-North Water Diversion Project. 【Method】The soil under Quercus variabilis natural secondary forest, Platycladus orientalis plantation, and Cunninghamia lanceolata plantation in the Karst area of Xichuan County of Henan Province was investigated in this study. Soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP) and available potassium (AK) contents were determined through laboratory experiments, and the stoichiometric ratios of each element were calculated to analyze the soil nutrient balance in forest habitats with different restoration modes. 【Result】The contents of SOC, TN and TP in different vegetation restoration modes in Karst area ranged from 10.23 to 28.99 g/kg, 0.89 to 2.42 g/kg and 0.43 to 0.77 g/kg, respectively; the mean values of soil stoichiometric ratios as C∶N, C∶P and N∶P were 10.41 to 11.89, 13.69 to 80.00 and 0.18 to 6.61, respectively. The soil nutrient contents and stoichiometric ratios were influenced by vegetation types and soil depth, and were higher in the surface soil (0-10 cm) than in the subsoil (>10-30 cm). Except for TP content, the soil nutrient content of the natural secondary forests was higher than that of the artificial forests. The correlation analysis showed that there were significant correlations among SOC, TN and TP contents under different vegetation restoration modes, indicating that the spatial distribution of the three had a more consistent variation pattern. 【Conclusion】In the water source area of the South-to-North Water Diversion Project, the naturally restored Q. variabilis secondary forest is an ideal vegetation restoration model, and all three stands were limited by nitrogen or phosphorus during the growth process. In the future stand management, nitrogen supplementation should be moderately strengthened for natural forests, phosphorus fertilizers should be applied to plantation forests, and the nutrient uptake efficiency of vegetation should be improved through measures such as inter-cultivation to promote coordinated development among vegetation soils.
【Objective】 Water is the main factor limiting the sustainable stability of forest vegetation in semi-arid regions. The purpose of this study was to characterize evapotranspiration and its components in a larch (Larix principis-rupprechtii) plantation on the north side of the Daqing Mountains in Inner Mongolia, thereby providing a theoretical basis for forest management based on forest-water relationships. 【Method】The sap flow, canopy interception, forest floor evapotranspiration, and soil water content in a larch plantation stand, along with meteorological factors were monitored simultaneously in the north side of the Daqing Mountains of Inner Mongolia, China. Then, the variations in total stand evapotranspiration and its components as well as the relationship between evapotranspiration and environmental factors were analyzed. 【Result】On the seasonal scale, the evapotranspiration values in 2016 and 2017 were 522.57 and 583.67 mm respectively, accounting for 120.13% and 167.34% of the precipitation in the same period. This interannual difference was influenced by both the air temperature and water content of the soil. The percentage of canopy transpiration to total stand evapotranspiration was 45.44%, that of forest floor evapotranspiration was 40.28% and that of canopy interception was 14.28%. On the monthly scale, canopy transpiration and interception accounted for 37.30%-52.43% and 8.61%-21.81% of total evapotranspiration, respectively, whereas 31.52%-48.15% of the total stand evapotranspiration was caused by forest floor evapotranspiration. Air temperature, wind speed, and water conditions were the main factors influencing total stand evapotranspiration and canopy transpiration. Interception of the stand was mainly determined via precipitation and air humidity. Variations in forest floor evapotranspiration were closely dependent on solar radiation, saturated vapor pressure deficit, and water content of the soil. Additionally, the total evapotranspiration was 28.06 mm lower than the precipitation in July 2016, and the ratio of precipitation to evapotranspiration in other months was 0.55-0.92 under the monthly scale. 【Conclusion】In the mountain plantation ecosystem of typical rain-fed forestry in a semi-arid region, the amount of precipitation cannot meet the water consumption demand of the plantation. Therefore, in future research, it is necessary to pay more attention to the effects of precipitation types and time patterns on evapotranspiration.
【Objective】Based on the forest resources inventory of Shicheng County, Jiangxi Province, the carbon stored in broad-leaved forests of different origins was estimated to quantify the contribution of driving factors to vegetation carbon storage, then evaluate the direct and indirect effects of such factors, providing a theoretical basis for the scientific management of forest resources.【Method】The biomass of the broad-leaved forest in Shicheng County was calculated based on statistical data from the 2016 forest resource inventory for Shicheng County, Jiangxi Province. Carbon stocks were calculated using the biomass conversion factor continuous function method, and random forest (RF) analysis and structural equation modeling (SEM) were combined to quantify and evaluate the contribution and impact of different drivers on the vegetation carbon stock.【Result】 The results of the random forest and structural equation models indicate that changes in the natural broad-leaved forest vegetation carbon storage are mainly determined by forest age, with a standardized total effect value of 0.54, followed by canopy closure at 0.36. No significant changes were observed in the amount of carbon stored in the forests, which is determined by canopy closure and stand density with total effect values of 0.49 and 0.19, respectively.【Conclusion】Canopy density, forest age and stand density are the main factors driving the carbon storage of subtropical broad-leaved forest ecosystems, providing new insights for understanding the carbon cycle and carbon accumulation in mid-subtropical forest ecosystems in response to climate change. The results of this study provide a theoretical basis for the managements of planted forests and assessment of the carbon sink potential of such forests.
【Objective】Land-use change has an important impact on ecosystem service values. Affected by natural climate change and human activities, land-use in Jiangsu Province has undergone dramatic changes, and changes in the ecosystem structure have led to changes in ecosystem service values. By exploring the relationship between the long-term sequence of ecosystem service values and land-use changes in Jiangsu Province, this study provides a scientific basis for sustainable ecological development and land-use planning and management in Jiangsu Province.【Method】 Taking Jiangsu as the research areas, based on the land-use data of each city from 1980 to 2020, the land use transfer matrix was established to analyze the characteristics of land-use changes in Jiangsu Province. The unit area value equivalent method was used to calculate the ecosystem service values of the prefecture-level cities and regions in Jiangsu Province in different periods. Spatial interpolation analysis of ecosystem service values was conducted using GIS technology to explore the spatiotemporal dynamics of ecosystem service values in Jiangsu Province. The elastic coefficient was used to calculate the ratio of the rate of change in land use to the rate of change in ecosystem service values to explore the response of ecosystem service values to land-use changes. 【Result】The amount of cultivated land transferred out was the largest from 1980 to 2020, and the amount of construction land transferred in was the largest. The conversion of cultivated land to construction land is the most important way of land-use transfer in Jiangsu Province, and wetlands are mainly converted to cultivated land. The calculation results based on the unit area value method show that the total ecosystem service value of Jiangsu Province keeps increasing. During the study period, the hydrological regulation value was the largest and the water supply value was the smallest for different ecosystem service types. From the perspective of different cities, the total ecosystem service values of Suzhou, Yancheng and Huai'an were relatively high. The results of the spatial interpolation analysis showed that the total ecosystem service values of Jiangsu Province had obvious continuity and differences over a long time series, which was generally high in the east and low in the west, and high in the south and low in the north. The elastic coefficient results showed that regions with high elastic values were mainly located in the eastern coastal area, regions with medium elastic values were relatively widely distributed as flakes, and regions with low elastic values were relatively dispersed. 【Conclusion】The land-use change in Jiangsu Province was significant. The distribution of high value ecosystem services has an important relationship with the coverage of land-use types and ecosystem service value coefficients. Land-use changes affect the value of ecosystem services and simultaneously determine the elastic changes in ecosystem service values. The higher the ecosystem service value coefficient, the more sensitive the ecosystem service value is to land-use changes.
【Objective】This study aims to explore a new idea of building ecological network to restore broken landscape and improve landscape connectivity, and to provide scientific basis for landscape pattern optimization and ecological red line protection in Xinfeng County. 【Method】 Taking Xinfeng County, Jiangxi Provinceas as the object, an ecological risk index was constructed based on landscape pattern to assess the ecological risk level, combined with the minimum cumulative resistance model (MCR) and landscape connectivity analysis, the ecological sources were identified and the general,important corridors were distinguished, and the county potential ecological network was constructed with Xinfeng County as the case. 【Result】 The ecological risk of urban construction and cultivated concentration area was relatively high, while the forest cover area was relatively low; the potential ecological network was consisted by 30 ecological sources, 67 ecological corridors and 25 ecological nodes. Important ecological corridors play a key role in the communication and connection of ecological patches in the east-west and north-south directions, and general ecological corridors connect multiple adjacent and scattered ecological sources together in Xinfeng County. 【Conclusion】 Landscape connectivity analysis can be used to determine not only patch importance but also corridor importance. The combination of ecological risk assessments and ecological network construction strengthens the integrity and reliability of county ecological network.
【Objective】With the continuous promotion of park city construction, many urban development goals require synergistic planning of blue-green spaces to achieve, and it is particularly important to scientifically develop criteria for measuring blue-green spaces in order to promote synergistic planning of blue-green spaces. 【Method】This study adopts a dual-performance measurement approach, based on a GIS platform, and takes Putuo District in Shanghai City as an example. It selects four performance measurement factors, namely spatial accessibility, spatial use level, waterlogging diversion, and cold island effect, from two aspects: recreation services and environmental ecology, to scientifically analyze the rationality of the layout of urban blue-green spaces, and to derive typical areas of low performance in Putuo District in Shanghai and analyze their causes. The layout optimization strategies of urban blue-green spaces are proposed from three aspects. 【Result】The performance rating of blue-green spaces in the whole Putuo District is not high, and there are several obvious characteristics of the blue-green spaces in Putuo District based on the double performance assessment: (1) the number and distribution of community blue-green spaces are small; (2) the performance of recreation services differs greatly from north to south and is unevenly distributed; (3) the environmental and ecological performance shows a better characteristic in the north and south but less in the middle district; (4) the performance rating of the whole blue-green spaces is not high, and the lowest performance areas are roughly. The lowest-performing areas are located in the central and southern regions. 【Conclusion】Based on the above characteristics, optimization strategies are proposed from three aspects: the layout of urban water bodies, the layout of urban green spaces, and the coordinated layout of blue-green spaces. The research results show that the current spatial layout of the city's water bodies and the coordinated layout of blue-green spaces can be improved. The research results will provide practical criteria and solutions for improving the current spatial layout and planning future blue-green spaces.
【Objective】The complexity of different forest types was evaluated to determine the main factors affecting stand structure and provide a theoretical basis upon which the precise forest management can be developed.【Method】A total of 30 permanent sample plots comprising different stand types (Betula platyphylla forest, Larix gmelinii-Betula platyphylla mixed forest and Larix gmelinii forest) in Cuigang Forest Farm, the Greater Khingan Mountains were investigated and 13 indicators selected to consider four aspects, namely stand structure, forest tree size diversity, forest dynamic and soil conditions. The stand complexity was evaluated using the radar chart method.【Result】The diameter distribution of the three stand types was found to be in the form of an inverse “J” pattern, with the overall tree distribution generally random; however, slight uniformity was observed. The tree size differentiation was inferior and middling, while stand density varied from medium to dense. The maximum stand mixing, Simpson diversity, Shannon-Wiener and Pielou evenness index results were obtained for L. gmelinii-B. platyphylla mixed forest, while the maximum stand volume and healthy wood proportion were observed in L. gmelinii forest. No significant differences were observed in terms of natural regeneration, soil organic matter, and soil humus layer thickness in different succession stages (P>0.05). The forest structure complexity was observed in the order of L. gmelinii-B. platyphylla mixed forest (0.45) > L. gmelinii forest (0.37) > B. platyphylla forest (0.31), during which the stand mixing, the Simpson diversity index, and the healthy tree proportion were the main factors affecting complexity. 【Conclusion】 The overall complexity of the forest structure is inferior. For the subsequent forest management, increasing the species diversity and improving the forest environment can promote positive progress in forest restoration and succession.
【Objective】The core area of the Zhengzhou Metropolitan area was investigated based on the construction of a regional ecological security pattern. The type and degree of land transformation were analyzed with the help of a land use transformation matrix, and the classification of land use spatial conflicts was identified, providing a basis for land use planning and management in the core area as well as a reference for the protection of ecological space. 【Method】The morphological spatial pattern analysis (MSPA) method was used to identify the target source area, the MCR model and gravity model were used to extract potential corridors and screen out important corridors, and the regional comprehensive ecological security pattern of “ecological source-ecological corridor-ecological network-hierarchical zoning” was constructed. The ecological security pattern was divided and analyzed. Next, the spatial characteristics of land use conflicts were identified, and the influencing factors were analyzed. 【Result】(1) The distribution of land use conflicts in the core area of the Zhengzhou Metropolitan area was significant, and the distribution of cultivated land ecological conflicts was relatively concentrated, mainly without conflicts. The distribution of ecological conflicts in construction land was relatively dispersed, the non-conflict areas were mainly concentrated in the middle of the main urban areas within each city scope, and the general serious conflicts and extremely serious conflicts were mainly located in the northern part of the research area. In the comprehensive ecological conflict of cultivated land construction, the size of each conflict level was no conflict, generally serious conflict, or extremely serious conflict, among which cultivated land ecological conflict dominated. (2) From 2000 to 2020, the regional landscape pattern in the core area of Zhengzhou Metropolitan area was highly fragmented and unevenly distributed, which constituted the main landscape type of ecological space in the study area. The proportion of cultivated land landscape and grassland landscape showed a partial decline. 【Conclusion】 The transformation degree and scale of land use in the core area of Zhengzhou Metropolitan area are relatively large, and the conflicts of cultivated land, construction land and comprehensive land use are relatively obvious. Therefore, the study has a positive significance for strengthening the control of various types of land use and improving the quality of ecological space.
【Objective】This study aims to elucidate the morphological characteristics, histological characteristics, and ultrastructure of Dalbergia odorifera root nodules and clarify the ultrastructure of rhizobium. The results from this study can provide an intuitive and precise primary data set for the classification of leguminous plant nodules.【Method】The paraffin sections, ultrathin sections and field emission scanning electron microscopy (FESEM) samples were all prepared from D. odorifera root nodules. Optical microscopy (OM) was used to observe the morphology and microscopic structure of nodules, while transmission electron microscopy (TEM) and FESEM were used to observe the ultrastructure of root nodule cells and rhizobium. Additionally, the leghemoglobin content of nodules in different periods was determined, and the relationship between root nodules structure and nitrogen fixation function was analyzed.【Result】(1) Morphological characteristics: from day one to day 60, the shape of D. odorifera root nodules gradually differentiated from round into oval, barbell and irregular oval, and the color changed from yellowish white to yellowish brown. The growing part of nodules gradually spread from the lateral root and base to the principal root. During the development of root nodules, the leghemoglobin content initially rose, then declined, with a peak at age of 3-5 d. (2) Histological traits: the root nodules of D. odorifera generally contained two to three infected areas. The vascular bundles were distributed around the infected areas, and the ringed vessels inside were connected by the end wall. (3) Ultrastructures: under TEM observation, the infected cells were significantly different from the uninfected cells. The volume of infected cells was enlarged without vacuoles and contained multiple vesicles with membranous structure. The vesicles were covered by bacteroids, which were differentiated from rhizobium, and organelles such as mitochondria and endoplasmic reticulum were squeezed to the edge of the cell wall. The uninfected cells were almost filled with vacuoles, and the cell wall was thick and uneven. Starch grains and some plastids existed around the nucleus. The morphologically diverse bacteroids have cell membranes and walls and contain polyphosphate (PP) particles and poly-β-hydroxybutyrate (PHB) particles. There were two membrane synthesis states in the infected cells of D. odorifera root nodules. In one, the membrane vesicles participated in the synthesis of peribacteroid membranes; in the other, a flocculent membrane appeared near the peribacteroid membranes and allowed the peribacteroid membrane to dissociate. FESEM showed a large number of long rod-like rhizobium intertwined and multiple peribacteroid membranes bonded together in a continuous shape to form a tight membrane system.【Conclusion】The D. odorifera root nodules are “determinate nodules”. The nodule age can significantly affect the leghemoglobin content in D. odorifera root nodules. The D. odorifera root nodules contain well-developed vascular tissues, and there are a large number of bacteroids that contain PP and PHB particles with an energy storage function as well as a strong peribacteroid membrane system. These structures provide supports to the nitrogen fixation function of D. odorifera root nodules.
【Objective】Beetles, as important biological components of forest ecosystems, can regulate litter decomposition and soil ecological processes. The authors aims to reveal the diversity characteristics of surface beetle communities in different aged poplar plantations and provide scientific support for exploring the structure, function and productivity maintenance for poplar plantations ecosystems.【Method】Poplar plantations of different stand ages (i.e., 6, 9, 12, 15 and 18 years) in the Yellow Sea Forest Park in Dongtai City of Jiangsu Province were selected for research conducted from 2020 to 2021. A pasteurized pot inducement method was used to collect different soil beetles. We investigated soil beetle community composition, structure and diversity characteristics in select poplar plantations.【Result】A total of 1 460 soil beetle specimens were collected during the study period, belonging to seven families and 28 species. The dominant species were Dolichus halensis, Agonum gracilipes, Harpalus chalcentus and Amara gigantea, which accounted for 79.11% of the total individuals. Common species were Harpalus calceatus, Harpalus griseus, Hypera conmaculata, Chlaenius micans, Harpalus amplicollis and Chlaenius costiger, accounting for 15.82% of the total number of individuals, and the remaining 18 species were rare populations, accounting for only 5.07% of the total number of individuals. The 12-year-old poplar plantation had significantly more beetle species and total individuals than other stand ages, while the 18-year-old poplar forest had the lowest. The species diversity of soil beetles varied by 33.83% across all plantation ages. Diversity increased first and then decreased with age of poplar plantation, with maximum and minimum values in the 12-year-old and 18-year-old plantations, respectively. There was no significant difference in beetle diversity in 6-, 9-, and 15-year-old poplar plantations.【Conclusion】Our study clarified that the individual number and species diversity of soil beetles are closely related to the growth and development stages of poplar plantations. Middle-aged stands in the rapid growth and development stage have higher beetle species diversity while mature stages or older stands have lower beetle species diversity. This study provides a theoretical basis for the protection of soil biodiversity in poplar plantations and the sustainable management of plantations.
【Objective】Rhynchium quinquecinctum was collected by the nest trap method, and Pseudoxenos iwatai samples were reared in the laboratory. The parasitism rate, extrusion time and position, eclosion time, and other behaviors of P. iwatai in the abdomen of R. quinquecinctum were observed by visual observation, photography and videography. 【Result】The parasitism rate of P. iwatai on R. quinquecinctum was 5.85% and the sex ratio of P. iwatai was 1∶6.24. In R. quinquecinctum, 48.98% of females and 51.02% of males were parasitized. The number of P. iwatai parasites in the abdomen of R. quinquecinctum ranged from one to nine, of which one to three were the majority, accounting for 91.54% of the total. The extrusion positions from the abdomens of R. quinquecinctum differed between females and males, and the number of females was the highest in the 3rd-4th segments of the host abdomen, accounting for 40.91%, while it was the highest in the 4th-5th segments of the host abdomen in males, accounting for 65.83%. Males were found on the 1st to 9th day after the R. quinquecinctum eclosion, and the number on the 1st day was the largest, accounting for 66.67%. The number of females observed on the 5th day after eclosion was the highest, accounting for 67.44%. There was a clear attraction to the male after the cephalothorax of the female was extruded from the host’s abdomen, and the attraction peak was at 5:30-6:30 and 13:00-14:30 of the day. Male eclosion occurred on the 5th to 10th day after R. quinquecinctum closion, and the peaks of eclosion were between 5:00-6:30, 9:00-11:00, and 14:00-15:30 in the day.【Conclusion】Different extruding positions from the abdomen of R. quinquecinctum for different sexes of P. iwatai were observed. An important behavior in the reproductive mating strategy of P. iwatai may be the overlap of the time of attracting males by females extruding from R. quinquecinctum and the peak time of male eclosion.
【Objective】 The distribution and change in relocated areas are signs and footprints of human activities, reflecting human disturbance to the natural ecological environment. This study systematically examined the temporal and spatial evolutionary characteristics of the relocation area. The data provide a theoretical basis for the improvement of ecological space quality and function. 【Method】Based on GlobeLand30 surface coverage data, superposition, spatial autocorrelation, and directional distribution analyses, and a landscape pattern index were used to study the change in quantity and spatial distribution characteristics of relocation land that was changed to ecological land in prefecture-level administrative regions of China in the past 20 years. 【Result】Relocation areas in China were mainly concentrated in central China, south China, and northeast China. Their spatial distribution displayed a significant autocorrelation. The hot and cold spots in the relocation area exhibited obvious directionality. The hotspot area gradually moved northeast and the cold spot area gradually moved north. There were four types of local spatial autocorrelations in the relocation area, including High-High (HH), Low-Low (LL), Low-High (LH), and High-Low (HL) aggregations. HH and LL were the main types, HH and LL showed a continuous trend, LH was scattered around HH, and HL was less common. The proportion of lanscape area are occupied by patches (PLAND) in the relocated area increased and the average area(MPS) gradually decreased, indicating that the relocated area gradually increased in the form of small patches. 【Conclusion】This study quantified the area and proportion of relocation area in prefecture-level administrative regions of China. Most of the relocation areas were located in economically developed cities, such as the central and eastern regions and southern regions. This study provides data that will support urban planning and development.
【Objective】The degree of forest fragmentation in 38 sample counties in the Beijing-Tianjin-Hebei Region was measured through satellite image data from 2000 to 2018. The impact of regional economic growth on forest resources was studied, and its internal impact mechanism was explored. The results provide a reference for the Beijing-Tianjin-Hebei Region to further realize a coordinated plan for sustainable development and environmental protection. 【Method】A model of the intermediary effects among economic growth, transportation infrastructure construction, and forest fragmentation was established through forest transformation theory, land use change theory, and growth axis theory, and the model was empirically tested. 【Result】In the relationship between the level of economic growth and degree of forest fragmentation in the Beijing-Tianjin-Hebei Region, every 1% increase in economic growth resulted in a 3% increase in forest fragmentation during the same period. In the relationship between economic growth and transportation infrastructure construction, every 1% increase in economic growth resulted in over 0.1% increase in highway density. In the relationship between traffic infrastructure construction and forest fragmentation, every 1-unit increase in highway density increased the number of forest patches in the region by more than 4. The mechanism test showed that in terms of economic growth affecting forest fragmentation, transportation infrastructure construction had a significant intermediary effect, with an intermediary degree of 23.255%. 【Conclusion】 The rise in economic growth significantly promotes forest fragmentation in the Beijing-Tianjin-Hebei Region. Improvement in economic growth can effectively promote the construction of transportation infrastructure and improve the distribution density of roads. The construction of transportation infrastructure significantly exacerbated regional forest fragmentation during the study period. In the process of economic growth, transport infrastructure construction correlated with an increase in forest fragmentation.
【Objective】 Pinus massoniana is the main coniferous tree species in subtropical China and P. hwangshanensis is the main constructive species in subtropical mid-montane region of the eastern China. Both species coexist at horizontal level but exhibit distinct vertical distributions. The objective of this study is to investigate the distribution patterns of P. massoniana and P. hwangshanensis forests and provide a theoretical basis for the scientific management and conservation of these forest resources. 【Method】 The study was focused on eight typical distribution areas in the eastern subtropical region of China. Non-metric multidimensional scaling analysis (NMDS) and multivariate regression trees (MRT) were employed to explore the differences in community structure and the main influencing factors between the two pine forests. Additionally, a linear mixed-effects model was used to quantify the response of species diversity indices to abiotic factors. Based on the principles for compiling the Vegegraphy of China, a preliminary quantitative classification of P. massoniana and P. hwangshanensis forests was performed. 【Result】 Significant differences were observed in the community structures of P. massoniana and P. hwangshanensis forests, with elevation identified as the primary influencing factor. Mean annual temperature had a significant effect on species richness within both communities, while mean annual precipitation had the most pronounced impact on overall species richness. Elevation exerted a significant influence on the evenness of the two communities. The preliminary vegetation classification resulted in the identification of six associations for P. massoniana forest and five associations for P. hwangshanensis forest. 【Conclusion】 Altitude variations shape the differences in community structure between P. massoniana and P. hwangshanensis forests and directly or indirectly influence species diversity in these communities. The vegetation classification highlights the diversification of vegetation types in the two pine forests and provides a reference for future classification efforts.
【Objective】 Plant height is a fundamental component of plant ecological strategies. This study aims to elucidate the phylogenetic conservatism of maximum plant height in Chinese angiosperms, investigate its variation across taxonomic groups and geographic regions, and explore its associations with environmental factors. 【Method】 Using data on the maximum plant height and geographic distribution of 20 295 Chinese angiosperm species, this study assessed the phylogenetic conservatism of maximum plant height among different growth forms, taxonomic groups, and vegetation zones. The study analyzed the correlation between the phylogenetic signal (Pagel’s λ) and factors such as latitude, temperature, and precipitation. 【Result】 The maximum plant height of Chinese angiosperms exhibited a strong phylogenetic conservatism (Pagel’s λ = 0.893). Among them, herbaceous plants showed slightly lower phylogenetic conservatism compared to woody plants, while six orders including Fabales exhibited phylogenetic signals higher than 0.9. The phylogenetic signals of all plants and woody plants displayed a unimodal relationship with latitude and temperature but showed a negative correlation with precipitation. The latitudinal pattern of phylogenetic signals in herbaceous plants was less pronounced, instead showing a multi-peak relationship with temperature and precipitation. 【Conclusion】 The maximum plant height of Chinese angiosperms demonstrated a clear geographic pattern in terms of phylogenetic conservatism, but the trend varied among different growth forms. Overall, the phylogenetic conservatism of maximum plant height of angiosperms and woody plants was stronger in middle latitudes compared to both high and low latitudes.
【Objective】 The process of community establishment in Chinese fir (Cunninghamia lanceolata) artificial forest, as one of the most significant ecosystems and sources of timber in China’s subtropical regions, is crucial for understanding the coexistence of species and the maintenance of biodiversity in plantation forests. The objective of this study is to investigate the process of community assembly and underlying mechanisms of Chinese fir artificial forests in Chinese subtropical, and provide a theoretical basis for enhancing the stability of local biodiversity in the management of Chinese fir artificial forests. 【Method】 Data from 143 pure Chinese fir artificial forests with a wide age range (3-100 years old) in subtropical China were collected through literature search and field sampling surveys. The changes in community phylogenetic structure with forest age and breast height diameter were examined to explore the variations in environmental filtration, competitive exclusion, and stochastic processes during stand development. 【Result】 Overall, as the forest age increased, the net relatedness index (NRI) and net taxon index (NTI) of plant communities in Chinese fir artificial forests initially decreased and then leveled off. The phylogenetic structure transitioned from aggregation to stochastic processes and eventually tended to diverge. The changes in NRI were more significant than those in NTI. In the early stage of young stands, NRI and NTI were both higher than 0, indicating aggregation in the phylogenetic structure. Before stand maturity, NRI was lower than 0, and NTI was higher than 0, showing divergence at the community level and aggregation at the end of the evolutionary tree. After stand maturity, both NRI and NTI were lower than 0, indicating a divergent phylogenetic structure. The trend of phylogenetic structure with diameter at breast height (DBH) was consistent with stand age. 【Conclusion】 The community assembly of Chinese fir artificial forests is primarily driven by environmental filtration, followed by a period of stochastic processes, and ultimately dominated by inter-biotic interactions as the forest stand grows and develops. Implementing appropriate forest management measures for different stand ages is beneficial for the coexistence of local species and the maintenance of plant diversity in Chinese fir artificial forests.
【Objective】Taking the Castanopsis spp. and Schima superba forests in subtropical typical evergreen broad-leaved forests in east China as the research subjects, the effects of environmental factors on aboveground biomass of the tree layer were studied.【Method】The aboveground biomass of the community was calculated based on the allometric growth equation of various plant species, and the Pearson correlation test was used to analyze the relationship between aboveground biomass and environmental factors in different types of evergreen broad-leaved forests. The mechanism of action between environmental factors and aboveground biomass was constructed by the partial least squares structural equation model (PLS-SEM), which was employed to analyze the relationship between multiple sets of variables.【Result】(1) The aboveground biomass of subtropical typical evergreen broad-leaved forests in east China showed a extremely significant increasing trend with forest age. (2) The aboveground biomass of Castanopsis and S. superba natural forests positively correlated with soil pH in the study area, and for the S. superba natural forest, air temperature and total solar radiation intensity factors significantly affected the aboveground biomass. (3) In the structural equation model constructed using environmental factors and the aboveground biomass of Castanopsis natural forests, the direct effect coefficient of climate factors on aboveground biomass was significantly greater than that of soil factors.【Conclusion】The total solar radiation intensity, soil pH, and soil bulk density significantly affected the aboveground biomass of subtropical typical evergreen broad-leaved forests in east China. Among them, in the Castanopsis natural forest, aboveground biomass positively correlated with air the soil pH factor. In the S. superba natural forest, aboveground biomass negatively correlated with air temperature factor and total solar radiation intensity factor and positively correlated with soil pH factor.
【Objective】We aim to reveal the activity rhythms and clustering patterns of the Reeve’s muntjac (Muntiacus reevesi) population under anthropogenic disturbance in Lüconghu Provincial Wetland Park of Zhejiang Province, to provide a basis for the scientific conservation and management of ungulates.【Method】We used infrared camera trapping to monitor the population of M. reevesi from February 2021 to January 2022. The daily activity rhythm and group patterns were analyzed based on the data from 1 896 independent valid photos.【Result】 The daily activity rhythms of M. reevesi varied across seasons. The minimum area of the overlap of daily activity rhythm curves (DARCs) was observed between winter and spring (Δ = 0.79, P<0.01), with higher intensity and significantly earlier activity peaks detected in the dusk of winter. The daily activity rhythms of M. reevesi also differed along altitudinal gradients. The minimum area of the overlap of DARCs was found between 700-900 m and 1 100-1 300 m (Δ = 0.76, P <0.01), with only one peak of activity detected in the dusk at 700-900 m. Seven group patterns were identified. The solitary individual pattern had the highest proportion (92.95%), followed by the adult female with fawn group (3.47%) and one female and one male group (2.37%). The remaining four group patterns (two female, two male, one male with fawn, two female with fawn) only accounted for 1.21% of the valid detections in this study.【Conclusion】The M. reevesi in Lüconghu Provincial Wetland Park of Zhejiang Province, is a diurnal animal mainly active in the morning and dusk and is mainly solitary. Its daily activity rhythm showed significant differences in different seasons and altitude gradients, which may be mainly influenced by factors such as temperature, food resources, vegetation type, and human disturbance.
【Objective】 This research aims to explore the impact of future climate change on predicted runoff trends in the Yangtze River basin and provide a basis for early flood warning and prevention measures in the Yangtze River basin and other regions. 【Method】 Temperature, precipitation and runoff in the Yangtze River basin from 1961 to 2014 were evaluated by using the multi-mode set average (MME) of the international coupled model intercomparison project phase 6 (CMIP 6) and the SWAT hydrological model and predicted under SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 emission scenarios from 2020 to 2099.【Result】 (1) Compared with the single model, MME showed better performance in simulating temperature and precipitation during historical periods, with a correlation coefficient with the observation value was >0.90. Further, MME simulated the spatial distribution of temperature and precipitation well. (2) The MME analysis showed that during 2020 and 2099, temperature and precipitation increases in the Yangtze River basin under all scenarios were <50% and <20%, respectively. Simulated temperature under the SSP5-8.5 scenario was 1.23 ℃ higher than that under the SSP1-1.9 scenario, and 0.99 ℃ higher than that under the SSP1-2.6 scenario. (3) Overall, future annual runoff of the entire Yangtze River basin increased significantly and reached 40 380 m3/s under the SSP5-5.8 scenario at the end of the 21st century.【Conclusion】 Temperature, precipitation and runoff in the Yangtze River basin are predicted to increase in the future, whereas flood disasters under low emission scenarios are relatively less likely.
【Objective】 In order to study a new way of biological control of pests on Populus pseudo-cathayana × P. deltoides leaves, the effects of compound inoculation with arbuscular mycorrhizal (AM) fungi on the resistance of P. pseudo-cathayana×P. deltoides leaves to Hyphantria cunea were investigated. 【Method】 One-year-old P. pseudo-cathayana × P. deltoides cuttings were inoculated with Rhizophagus intraradices (RI) and Funneliformis mosseae (FM) by single and mixed inoculation (M) in a greenhouse, with no inoculation (CK) as the control. The chemical defense ability of secondary metabolites, defense enzymes and protease inhibitors in poplar leaves was determined, and the larva of H. cunea was used as a bioassay object to determine its anti-insect effect.【Result】 In 120 days, the mycorrhizal infection rate, arbuscular growth rate and number of vesicles in the root of the M group were higher than those of the FM and RI groups. Meanwhile, the M group could improve the chemical defense ability of the leaves of P. pseudo-cathayana × P. deltoides to a certain extent. The contents of total alkaloids and cellulose and the activities of peroxidase (POD), catalase (CAT), lipoxygenase (LOX), polyphenol oxidase (PPO), chymotrypsin inhibitor (CI) and trypsin inhibitor (TI) in leaves were significantly higher than those in the RI, FM and CK groups (P<0.05). The food intake, fecal output, cellulase activity, acetylcholinesterase (AchE) activity and multifunctional oxidase (MFO) activity of the third instar larvae in the M group were significantly lower than those in the FM, RI and CK groups (P<0.05). The body length, food availability, trypsin activity, carboxylesterase (CarE) activity, and glutathione S-transferase (GSTs) activity of the third instar larvae were significantly higher than those of the RI and FM groups (P<0.05). The food consumption rate and α-amylase activity of the third instar larvae did not significantly differ from those of the RI group, and the body weight of the third instar larvae did not significantly differ from those of the FM group. Body weight, food intake, food consumption rate, cellulase activity, GSTs activity, CarE activity, AchE activity and MFO activity of the fourth instar larvae were significantly lower than those of the FM, RI and CK groups (P<0.05), the fecal output of the fourth instar larvae was significantly lower than that of the RI and CK groups (P<0.05), and the trypsin activity of the fourth instar larvae was significantly higher than that of the other three groups (P<0.05). The body length and food availability of the fourth instar larvae did not significantly differ from those of the RI group, and the α-amylase activity of the fourth instar larvae did not significantly differ from those of the FM and RI groups. The body length, body weight, food intake, fecal output, food utilization, α-amylase activity, cellulase activity, GSTs activity, CarE activity, and MFO activity of the fifth instar larvae were significantly lower than those in the FM, RI and CK groups (P<0.05). The food consumption rate of the fifth instar larvae was significantly lower than that in the FM and RI groups, and the AchE activity of the fifth instar larvae was significantly lower than that in the FM group (P<0.05). The trypsin activity of the fifth instar larvae was significantly higher than that of the other three groups (P <0.05).【Conclusion】 The mixed inoculation of RI and FM could induce the chemical defense performance of P. pseudo-cathayana × P. deltoides leaves in the aspects of secondary metabolites, defense enzymes, and protease inhibitors. The anti-insect performance of combined RI and FM inoculation was better than that of single RI and FM inoculation and no AM fungi inoculation and had certain inhibitory effect on the larva of H. cunea. In practical application, combined RI and FM inoculation can be prioritized.
【Objective】 Aiming to address the phenomena of low contrast, low saturation, and hue shift in unmanned aerial vehicle (UAV) photography images of forestland under hazy conditions, this study proposes a de-fogging method for UAV images adapted to forestland aerial photography scenes based on Resnet. 【Method】 The UAV images in woodland scenes were characterized by texture features and rich high-and low-frequency information. GFF information transfer modules were attached to each layer of the backbone network to transform feature maps into weight maps for filtering and sending to other layers, and thresholds were set at the receiving end to avoid the adverse effects of redundant information. Then, the global defogging effect was enhanced by dense links to improve the defogging quality in high- and low-frequency image regions. Finally, defogging experiments were conducted on a test set of woodland UAV images with fog. 【Result】 The average structural similarity of DHnet on the test set of woodland images was 0.83, and the average peak signal-to-noise ratio was 22.3 dB, which represented improvements of 4.8% and 39.3%, respectively, compared with the Resnet method. 【Conclusion】 The algorithm can effectively reduce tonal shift and remove residual fog, improving the color fidelity and detailed information retention of aerial woodland fog images obtained by UAV photography.
【Objective】 The objective of this study was to explore the extraction of spatio-temporal distribution of aquatic vegetation in lake wetlands using Sentinel-1 and Sentinel-2 data. 【Method】 Hongze Lake National Wetland Park was chosen as the research area. Based on the combination of Sentinel-2 MSI images and Sentinel-1 SAR images, the object-oriented image analysis was used. The feature set was constructed by using EVSI, NDVI, SR feature index and contextual features between objects, as well as differences in the backscatter coefficients of the SAR images corresponding to differences in the height of the emergent vegetation types. A decision-tree model was established at the object level to classify the wetland, and the spatio-temporal distribution of the aquatic vegetation and the emergent vegetation in the Hongze Lake National Wetland Park was acquired. 【Result】 The classification accuracy and the Kappa coefficient of aquatic vegetation were observed to be 89% and 0.85, respectively, and that of the emergent vegetation was 85.2% and 0.76, respectively. The results showed that, compared with the results of the pixel-based analysis method, the accuracy of object-based image analysis was higher. The wetland aquatic vegetation was dominated by submerged and emergent vegetation; among the emergent vegetation, lotus leaves and reeds were dominant. 【Conclusion】 The methods proposed in this study were feasible, and the results could provide a scientific basis for managers and planners of wetlands.
【Objective】 The objective of this study is to construct and optimize the ecological spatial network in Jiuquan City, aiming to enhance the quality of the ecological environment, harness regional ecological functions, and prevent desert expansion. 【Method】 By integrating remote sensing ecological index (RSEI) with the ecological spatial network, this study assessed the spatial pattern of landscape in Jiuquan City. By using complex network theory, the study identified weak ecological source areas and proposed optimization strategies. 【Result】 (1) The RSEI exhibited a spatial pattern in the Jiuquan City, with low values in the northern region and high values in the central and southern regions. (2) The potential ecological spatial network in Jiuquan City comprised 332 ecological nodes and 656 ecological corridors. Through the simulation of additional edges based on the region with the lowest RSEI, 242 edges were added, resulting in the inclusion of nine ecological stepping stones. (3) After the addition of edges, there was a noticeable improvement in the robustness of network nodes and connections, while the improvement in edge robustness was slight and not significant. 【Conclusion】 The optimization strategies of adding edges and stepping stones to weak ecological areas can enhance the stability and ecological restoration capacity of the ecological spatial network in Jiuquan City. The construction of new ecological corridors to enhance connectivity between source areas would facilitate regional ecological benefits and provide strategies for future ecological engineering projects in Jiuquan City.
【Objective】 The Songhua River wetland is the most important ecosystem barrier in Harbin. This paper quantitatively studied the evolution and main influencing factors of the landscape pattern of the Songhua River wetland ecosystem in Harbin over the past 20 years, and we aim to provide a reference for wetland planning. 【Method】 Choosing the Harbin basin and its surrounding ecological area as the research object, Landsat remote sensing images from 2000, 2005, 2010, 2015 and 2020 were processed with the help of the GIS platform. The Fragstats software was used to analyze the regional landscape pattern index and explore the spatio-temporal evolution characteristics of the landscape pattern. Finally, SPSS was used for the statistical analysis of the factors affecting landscape pattern. 【Result】 (1) From 2000 to 2020, the water area (including wetland) continuously increased, while the cultivated-land area continuously decreased, which was the primary change feature of landscape pattern in the study area. The decreasing cultivated land was the main contributing factor of increasing water area, grassland, construction land, forest land and other land areas at 343.142 1, 2.484 9, 94.041 9, 35.469 0 and 1.980 0 km2, respectively; among them, the growth rate of water area, grassland, forest area and other land area exceeded 100%, and the area expansion showed an upward trend. (2) From the perspective of plaque types, the degree of fragmentation of each plaque increased to varying degrees during the 20 years, and the wetland landscape type structure tended to be complicated. From the landscape-level perspective, the overall landscape richness has increased, but the connectivity was poor, and the degree of external interference was relatively significant. (3) Urban economic development, climate and industrial structure were the main driving factors to stimulate the change of landscape pattern of the Songhua River wetland in Harbin. With the establishment of the Songbei District and the rise of tourism, relevant infrastructure has crowded the space of some water areas (including wetlands) along the river; wetland marshes and cultivated land have been divided into numerous patches, the overall landscape pattern tends to be fragmented, and human drivers have gradually become the dominant factors. 【Conclusion】 The landscape type of the Songhua River wetland in Harbin is a complicated structure. As human influence factors become more profound, the fragmentation degree of water patches increases, there is a serious loss of cultivated-land area, and the contradiction between cultivated-land protection and ecological protection remains prominent.
【Objective】 Small and micro wetlands provide several important ecological functions, such as habitat support for key species, biological transfer, hydrological regulation and water purification, education and rest. Wuxi City in China contains numerous wetlands, of which most over 8 hm2 have been protected in recent years. However, not all small and micro wetlands have been protected in Wuxi City, and research regarding spatiotemporal changes in these habitats under various factors is lacking. Thus, analyzing the temporal and spatial characteristics and driving forces of small and micro wetlands can provide a theoretical basis for wetland ecological restoration and protection construction.【Method】 Based on Landsat satellite images in 2000, 2010 and 2020, patch information of small and micro wetlands in Wuxi City were extracted using support vector machine classification and other methods. Combined with meteorological and land use data, the spatiotemporal evolution of small and micro wetlands in Wuxi City and its influencing factors were analyzed.【Result】 (1) Within the past two decades, the total wetland area in Wuxi City has decreased from 178 000 hm2 in 2000 to 104 000 hm2 in 2020. Among them, the total area of small and micro wetlands has decreased from 19 000 hm2 in 2000 to 15 000 hm2 in 2020. (2) In terms of spatial distribution, small and micro wetlands in Wuxi were mainly distributed in the county-level city Yixing, which accounted for 40.0% of the area of Wuxi City. Small and micro wetlands in Wuxi City predominantly consisted of natural wetlands, accounting for up to 61.0% and displayed marked seasonal variation characteristics. In 2020, the proportion of seasonal small and micro wetlands in the total area of small and micro wetlands was as high as 73.8%. (3) The dynamic of small and micro wetlands in Wuxi City were positively correlated with temperature and precipitation due to natural factors and human activities. Specifically, human activities had a significant impact on the decline of small and micro wetland areas, and the transformation between wetland and other land types accelerated the decline of wetlands.【Conclusion】 Wuxi City is rich in small and micro wetland resources, which are in rapid decline due to seasonal and land use changes. Thus, the protection and restoration of small and micro wetlands must be enhanced to mitigate the negative impacts imposed by different factors.
【Objective】 The objectives of this study were to explore the temporal and spatial evolutions of wetland landscape in Changsha from 1999 to 2019, to comprehensively analyze the dynamic-change characteristics of wetland-landscape patterns in Changsha in the same period, and to explore the influence mechanism of natural and human factors on wetland-landscape patterns, so as to provide an important theoretical basis for the protection and rational utilization of wetlands in Changsha. 【Method】 Based on global surface water data (GSWD), combined with meteorological and hydrological data, this paper adopted the methods of wetland distribution information extraction, wetland type classification and landscape pattern index, aiming to achieve long-term and continuous monitoring of the dynamic evolution of annual wetland-landscape patterns in Changsha City from 1999 to 2019 based on the seasonal and fluctuating characteristics of wetlands. In addition, we analyzed the evolution trend of its long time scale, as well as the short-term fluctuation change characteristics. 【Result】 (1) Since 1999, the wetland area in Changsha has been overall increase, with permanent river being the main wetland type. From 2007 to 2009, there was a large fluctuation in wetland landscape, as represented by the transformation of permanent rivers and lakes to seasonal rivers and lakes, respectively, in the early stage, and by the reversal of fragmentation after 2008. The fragmentation degree of wetland-landscape pattern in Changsha continuously intensified until 2017 and later began to gradually recover. (2) The wetland-landscape pattern in Changsha was greatly affected by the natural factors such as precipitation and runoff from the Xiangjiang River and extreme freezing disasters that led to large fluctuations of the wetland-landscape pattern. The wetland landscape pattern in Changsha was also affected by human factors such as growing population and urban expansion that may lead to the intensification, but government policies and measures had a positive effect on wetland restoration. 【Conclusion】 It was feasible to use GSWD to extract wetland information. The wetland area in Changsha had continued to grow, among which permanent river was the main wetland type. The results from this study could provide important scientific references for the protection and rational utilization of wetlands in Changsha.
【Objective】 The construction of natural resources classification systems for protected areas is important for the conservation, supervision, and identification of rights and value-added assets in protected areas, witch can help modernizate their governance system and capacity. 【Method】 The key problems of natural resources classification in protected areas were analyzed and identified the concept of natural resources using a systematic process. Taking the investigation of protected areas as the starting point, attempts were made to establish a natural resources classification system. 【Result】 The problems of natural resources classification in various protected area stem types from the inadequacy of the classification systems, as such lack of key resources, unclear levels, overlapping resources, and unclear scope. The natural resources classification systems under the new protected areas systems involved a single natural resource classification system with four categories, eight subcategories, and twenty-one subdivisions. On this basis, the system of an organic complex of natural resources was proposed, including natural ecosystems, natural landscapes, and natural monuments. Finally, a new natural resources classification system of “Single natural resource classification system + Classification system of natural resource organic complexes” was established under the concept of new protected areas system. 【Conclusion】 Based on the results of special resource surveys on animals, wetlands, and the results of scientific research on protected areas, it is necessary to continue to deepen and refine the classification systems. Relevant documents should be issued as soon as possible to accurately define the boundaries of various natural resources. Concerning the main protection objects of protected areas, focus on the classification management of natural resources. Under the general pattern of unified management of natural resources, the classification systems of natural resources in protected areas should be integrated into the unified management systems to build a foundation for the effective management of natural resources in protected areas.
【Objective】 To explore the potential problems and conflicts of habitat quality in the Qilianshan Nature Reserve as per future land use changes; to respond to the regional ecological environmental protection policy per the concept of “Mountain, Water, Forest, Field, Lake, Grass, and Sand”, and to provide a scientific basis for regional ecological management and sustainable development. 【Method】 Based on five phases of land use data from 2000 to 2020, the PLUS model was used to simulate land use under different scenarios in the future through 2030. The InVEST model was coupled to assess and predict the current and future habitat quality of the Qilian Mountain Nature Reserve. 【Results】 Land use in the Qilian Mountain Nature Reserve was dominated by grassland, forest land, and unused land, and an increase in the area of ecological land. The increase in the area of ecological land under the ecological protection scenario was significantly higher than under the natural development scenario for 2030. Habitat quality showed a spatial distribution pattern of “low in the northwest and high in the southeast,” with the mean value of habitat quality from 2000 to 2020 as follows: 0.656 2, 0.656 3, 0.665 8, 0.664 6, and 0.665 7, respectively. This showed a fluctuating trend of increasing, decreasing, and increasing values. The average value of habitat quality in 2030 was 0.667 9 under the ecological protection scenario and 0.665 6 under the natural development scenario. The total habitat contribution under the ecological protection scenario was greater than that under the natural development scenario. The degree of habitat degradation increased and then decreased from 2000 to 2030, showed a spatial distribution from weak to strong circles from the center outwards, with the most degraded areas located at the edges of grassland adjacent to unused land—the areas most affected by human activities. 【Conclusion】 The habitat quality of the Qilian Mountain Nature Reserve is developing in a positive direction; the habitat quality under the future ecological protection scenario is significantly better than that under the natural development scenario; strengthening the protection of ecological land such as woodland and grassland is conducive to the improvement of habitat quality.
【Objective】 Changes in landscape patterns and ecosystem service values (ESVs) in the Fuxian Lake basin are affected by the “Four Retreats and Three Returns” protection policy. Quantitatively understanding such changes can provide a reference for the protection of watershed landscapes. 【Method】 Four sets of remote sensing images taken from 2006 to 2021 (before and after the implementation of the “Four Retreats and Three Returns” protection policy) were selected for landscape classification, and the land use dynamics, transfer matrix and landscape pattern indices were calculated. The ESVs were evaluated using the equivalent factor method and the SPSS software package was used to analyze the correlations between the ESVs in the watershed and the landscape pattern indices. 【Result】 The results indicated that the forested and water system areas in the Fuxian Lake basin were small, while the construction land area was expanding before the implementation of the “Four Retreats and Three Returns” protection policy. The landscape pattern was also complicated and fragmented, with weak connectivity and low ESVs. After the policy was implemented, the forested area increased significantly, the expansion of construction land slowed significantly, and the rate of water system reduction decreased. The degree of fragmentation of the landscape pattern also decreased and the connectivity was enhanced. The ESVs in the basin increased significantly. (2) The ESVs in the Fuxian Lake basin were connected with the landscape pattern, and the total basin ESV was significantly positively correlated with CONTAGE and negatively correlated with SHDI and SHEI. Among the individual ESVs, supply services were significantly negatively correlated with LPI, regulation and support services were significantly positively correlated with CONTAGE and significantly negatively correlated with SHDI and SHEI, and cultural services were significantly positively correlated with CONTAGE. 【Conclusion】 Future studies should focus on the mechanism behind these changes and provide a reference for the next step in protecting and managing the Fuxian Lake basin.
【Objective】 As per the new era and the comprehensive development of territorial spatial planning and the proposed rural revitalization strategy, the evaluation of village development potential is basic to rural planning and construction. The evaluation is also the core link to village planning under territorial spatial planning and a key guide to the classification of villages. 【Method】 Taking “background explanation-potential evaluation-village classification-classification pattern-development strategy” as the research path, seven criterion layers and 19 indicator layers were constructed according to the structural framework of target layer-criterion layer-indicator layer. The weights of indicators were determined by AHP and the entropy weight method. Based on this, villages in Lingbi County in Anhui Province were classified. Next, the landscape pattern of classified villages was analyzed based on Fragstats. 【Result】 Lingbi County in Anhui Province was divided into four types of villages: agglomeration enhancement, suburban integration, characteristic protection and relocation and withdrawal. Agglomeration enhancement villages had the largest landscape area, the most complex landscape shape, and the highest landscape agglomeration degree. The patch integration degree of suburban-integrated villages was the highest with the best landscape connectivity. The landscape complexity of the villages of relocation and withdrawal was the highest. Corresponding development strategies were proposed for different village types. 【Conclusion】 Corresponding development strategies are put forward for different village types: agglomeration and upgrading villages have a certain scale, an important breakthrough for rural modernization. During construction, the village layout should be optimized, the internal structure of the village should be properly adjusted, the construction of the village infrastructure should be improved, and the village’s appearance should be improved. The relationship between protection and development should be fully considered, and the integrity, authenticity, and continuity of village characteristics should be emphasized. In the construction of suburban-integrated villages, we should make use of their location advantages, focus on improving the village’s internal facilities, optimize the spatial layout, and discourage continuous expansion. At the same time, the overall style of the village should be different from the urban landscape—industrial development should be combined with the characteristics of the villages, village resources should be integrated, and the docking and integration of urban and rural industries should be strengthened. As per different industries, block division is conducted to realize the centralized development of industry and the intensive development of land. The natural resources in the villages should be protected, and rational land use and local resources should be combined to build characteristic tourism projects to develop village tourism. The relocation and withdrawal villages should merge, through spatial integration, with neighboring villages with high development potential to form the scale effect of village merger. The merger will enhance development potential and comprehensive competitiveness. The intention to relocate villagers and the restoration of rural ecology should be important considerations. The study provides method reference and a decision basis for the evaluation and classification of county-level rural potential.
【Objective】 This study explored the rules governing the spatial relationships among mountains, water and the locations of traditional villages to shed light on their reasonable protection and construction. 【Method】 Jinting Town, a scenic location near Taihu Lake with well-protected traditional villages and towns, was selected as the research subject. Based on extracted digital topography, satellite maps and the general planning CAD base map data for Jinting Town, we analyzed the spatial relationships among the mountains, water and villages using ArcGIS (ver. 10.0). We also analyzed the correlations between the distributions of mountains and water with the distribution of villages. We used spatial logistic regression modeling to analyze the factors affecting the distribution of traditional villages. 【Result】 The spatial distribution of traditional villages in Jinting Town exhibited a cluster mode, with circular spatial density characteristics. The impacts of mountain elevation and distance from a river were negatively correlated with the spatial distribution of traditional villages. Owing to the terrain, which is surrounded by lakes on all sides, the circular distribution of traditional villages in Jinting Town has a special research value. The elevation of the mountains affected the direction of the water system and roads in Jinting Town and was the main driving force for constructing villages in the region. The proximity to the water also affected the distribution of villages. 【Conclusion】 Using ArcGIS and logistic regression modeling, the spatial relationships among villages, mountains, and water can be analyzed and widely used in the pre-planning stages of protecting and constructing traditional villages and towns.
【Objective】 Ankyrin is a family of adaptor proteins that connect the cytoskeleton to the plasma membrane. However, the functions of insect ankyrin are poorly understood. In this study, the Ankyrin genes of Hyphantria cunea were cloned and their expression characteristics were determined in different developmental stages and tissues of H. cunea. The mortality rate of H. cunea was measured under the stress of exposure to nucleopolyhedrosis virus, which provided a theoretical basis for further developing synergists for NPV-based control strategies. 【Method】 The Ankyrin1 (HcAnk1) and Ankyrin2 (HcAnk2) genes were screened by a transcriptome library, and the characteristics of the two Ankyrin genes were determined using bioinformatics. Using qRT-PCR, the expression of HcAnk1 and HcAnk2 genes were determined at different developmental stages and in different tissues, and under different HcNPV concentrations. The survival rate of H. cunea larvae under HcNPV stress was investigated after the gene silencing of HcAnk1 and HcAnk2 using an RNAi technique. 【Result】 The open reading frames of the HcAnk1 and HcAnk2 genes were 1392 and 1866 bp, encoding 463 and 621 amino acids, respectively. The molecular weights of the HcAnk1 and HcAnk2 proteins were 59.18 and 69.19 ku, respectively, and the theoretical isoelectric points were 5.74 and 8.66, respectively. A phylogenetic analysis showed that HcAnk1 was closely related to Trichoplusia ni and was clustered into one group. HcAnk1 and HcAnk2 were expressed at all developmental stages, with the highest expression in the egg stage and the lowest expression in the sixth instar larva. The highest expression of HcAnk1 and HcAnk2 was observed in the midgut and hindgut, respectively, but HcAnk1 was not detected in the ovary or testis, while HcAnk2 was mainly expressed in the midgut and testis. In tests with different levels of HcNPV stress, the transcription levels of HcAnk1 and HcAnk2 were induced at low concentrations and inhibited at high concentrations. The relative growth rate and food conversion efficiency (ECD) were significantly decreased after silencing HcAnks in H. cunea larvae. Additionally, the H. cunea with HcAnks silencing were significantly less resistant to HcNPV. 【Conclusion】 HcAnk1 and HcAnk2 play an important role in the resistance to HcNPV. HcAnk1 and HcAnk2 can be used as HcNPV synergists for the pollution-free control of H. cunea.
【Objective】 The study aimed to understand the health status of plantations in nature reserves for forest management and the construction of nature reserves. 【Method】 A total of 36 sample plots were surveyed in the pure Larix gmelinii var. principis-rupprechtii and Pinus sylvestris var. mongolica plantations in the Saihanba Nature Reserve of Hebei Province using the stratified random sampling method. A total of 17 indicators, including the five aspects of productivity, stand structure, species diversity, soil quality, and stability, were selected to establish an indicator system for assessing forest health. The forest health index was calculated by principal component analysis, and the forest health grades were classified using the K-means clustering method. The accuracy of the clustering results was verified by Fisher’s discriminant analysis. 【Result】 The forest health index of the study area ranged between -1.02 and 1.46. The soil quality and stand structure were the most important indicators that influenced forest health in the study area. The proportionate areas were in the following order: mid-health (50%) > unhealthy (25%) > sub-health (19%) > healthy (6%). The health status of L. gmelinii var. principis-rupprechtii forests was better than that of P. sylvestris var. mongolica forests for middle-aged (20-30 a) and near-mature (> 30 a) stands. The forest health indices of L. gmelinii var. principis-rupprechtii and P. sylvestris var. mongolica forests tended to decrease with increasing stand density. 【Conclusion】 The plantations in the Saihanba Nature Reserve were primarily in the mid-health and non-health states. Therefore, the findings revealed that effective management strategies are urgently necessary for improving forest health in the study area.
【Objective】 A scientific evaluation of the development process and prediction of the development trend of state-owned forest areas would be of great significance. It could provide guidance for the continuous in-depth reform of state-owned forests, promoting the coordinated development of the regional economy, and maintaining ecological security, defense security, and timber reserve security at the national level.【Method】 Taking the state-owned forest region of the Great Khingan Mountains in Heilongjiang Province as the study area, an evaluation index of the transformation and development process was constructed based on the five system layers of resource conservation, industrial development, enterprise management, the welfare of local people, and support security. The entropy weight TOPSIS method was used to quantitatively evaluate the transformation and development process from 2000 to 2020, and the gray GM (1,1) model and policy adjustment method were applied to fit the development trend from 2021 to 2025.【Result】 First, the funds raised by enterprises, professional and technical personnel, attraction of investment, average annual wage of on-the-job employees, proportion of the output value of the tertiary industry, and forest land area were important indicators affecting the development of the research area. Second, the bottom line goal of “protecting ecology and people’s livelihood” was achieved. Third, the development trend of each system level was not coordinated, and there was a clear developmental lag in the progress of industrial development, enterprise management, and support systems. Fourth, the development of the research area was heavily dependent on policy dividends, while the endogenous power and vitality need to be improved. Fifth, the study area faces much uncertainty, and the development trend during the “14th Five-Year Plan” period did not have an optimistic outlook. 【Conclusion】 On the basis of consolidating the natural environment and the well-being of local people, optimizing the industrial structure, improving the management efficiency of forest industry enterprises, and consolidating support and ensuring capability are the key strategic priorities for advancing the development of the research area.
【Objective】 Owing to tighter resource constraints and intensive land development, we analyzed the ecological, social, and economic functions of urban green space system (UGSS), and determined its evolutionary characteristics and driving mechanism. To provide a basis for efficient urban land allocation and decision-making support for urban construction. 【Method】 Xuchang City (Henan Province) was selected as a case study, using time nodes data from 2010, 2014 and 2019. We applied the backtracking method with a land use simulation model and random forest regression; driving factors such as policy, natural and socioeconomic factors were analyzed. 【Result】 (1) From 2010 to 2019, Xuchang’s UGSS developed from the northeast and north, which was consistent with the guidance of urban planning policies. (2) The impact of planning policy on UGSS could either be positive protection or negative erosion. The GeoSOS-FLUS model and the backtracking method could simulate the changes in the UGSS, which could then be used to determine the impacts of the planning policy and establish an analytical framework for policy failure. (3) Socioeconomic factors had a significant impact on changes in the areas of township-level UGSS and the landscape pattern index, whereas natural factors had lower impacts. In Xuchang, which located on a plain, topography, had the smallest impact on changes in UGSS. The patch density changes in the UGSS had a high goodness of fit with each driving factor, which reflects the correlations between the UGSS landscape pattern and its driving factors. 【Conclusion】 Planning policy is the guiding driver of changes in UGSS, whereas socioeconomic factors directly drive changes in UGSS and natural factors have relatively little impact. Determining the evolution law of UGSS is necessary for enhancing scientific and forward-looking planning for UGSS under the new territorial spatial planning system.
【Objective】An investigation on the effects of arbuscular mycorrhizal (AM) fungi inoculation on the growth, physiological metabolism, and salt tolerance of Xanthoceras sorbifolium under salt stress was conducted.【Method】In this study, Funneliformis mosseae was used to infect seedlings and the pot experiment was carried out using one-year-old X. sorbifolium seedlings. We applied different concentrations of NaCl stress (0, 80, 160, 240, and 320 mmol/L). After the stress period, the biomass, colonization characteristics, and physiological indicators of the X. sorbifolium seedlings were measured.【Result】(1)The aboveground and underground biomasses of X. sorbifolium seedlings were enhanced significantly by AM symbiosis upon exposure to salinity. Increasing salinity significantly caused a decrease in the mycorrhizal colonization rate.(2)AM fungi inoculation significantly improved the contents of soluble protein, proline, glutathione(GSH), and ascorbic acid (AsA), and resulted in an increasement in the activities of superoxide dismutase (SOD) and peroxidase (POD), yet a reduction in the relative conductivity and accumulation of malondialdehyde (MDA).(3)Furthermore, two-way analysis of variance(Two-way ANOVA)demonstrated that the duration and concentration were interactively and significantly affecting correlated with the content of MDA, proline, soluble protein, and AsA (P<0.01). Based on principal component analysis(PCA), it was found that the inoculation group had the most profound impact on the physiological characteristics of X. sorbifolium at 320 mmol/L NaCl treatment.【Conclusion】This study found that inoculation with AM fungi may advance osmotic mediation ability, significantly improve the activities of antioxidant enzymes and the contents of antioxidants, and enhance the salt tolerance of plants and eventually promote the growth of X. sorbifolium seedlings under different salt concentrations.
【Objective】This study explored the species diversity of the understory plant community of a Platycladus orientalis plantation across 50 years in Quanshan Mountain and Yunlong Mountain, Xuzhou City. We then investigated the response of the understory plant diversity to the canopy density.【Method】The canopy density of the plantation was measured using a standard sample plot survey method and divided into five canopy density grades ([0.9,1.0], [0.8,0.9),[0.7,0.8),[0.6,0.7),and [0, 0.6) according to the current field stand conditions. The plant species composition and diversity characteristics were then evaluated for different canopy density forests.【Result】The results identified 129 species of trees, shrubs, and grasses in 65 families and 116 genera in the P. orientalis plantation. As the canopy density decreased, the number of plant species initially increased and subsequently decreased, and the understory species exhibited a gradual transition from shade-tolerant to sun-tolerant succession pattern. Plant life forms were generally complex and stable. Moreover, the Shannon-Wiener diversity index initially increased and subsequently decreased with the decrease in canopy closure. The canopy closure values of canopy density categories [0.6, 0.7) and [0.7, 0.8) were significantly higher than those of categories [0.9,1.0],[0.8,0.9) and [0,0.6). No significant differences were observed in the Margalef richness and Pielou evenness indexes among the five canopy densities (P > 0.05). The Simpson dominance index initially increased and subsequently decreased with the decrease in canopy density, and was the highest at the canopy density [0.6, 0.7). Correlation analysis between the canopy density and the plant species diversity index of the P. orientalis plantation revealed a negative correlation between canopy density and the Shannon-Wiener diversity, Margalef richness, and Pielou evenness indexes. Furthermore, the canopy closure was a very weak negative correlated with the Simpson dominance index.【Conclusion】In summary, the plant diversity in the P. orientalis plantation was optimal under medium canopy density [0.6, 0.7). Higher or lower canopy densities may lead to the relative reduction of the species composition and diversity of the plants in the plantation, which is harmful to the maintenance of the P. orientalis plantation.
