【目的】开展麋鹿(Elaphurus davidianus)生境适宜性评价并估算其生态容纳量,为麋鹿种群结构调控与栖息地生态修复提供参考依据。【方法】以江苏大丰麋鹿国家级自然保护区为研究对象,利用高分辨率无人机(UAV)技术替代传统的样线样方调查方法,获取麋鹿出现点数据与土地利用分类图,选取10个生境评价因子,运用层次分析法(AHP)确定权重,采用ArcGIS 10.8进行加权总和分析,得出麋鹿夏季不同等级生境分布图;结合不同等级生境面积占比情况及各类草本植物的养分含量估算保护区麋鹿夏季生态容纳量。【结果】保护区内麋鹿种群主要出现在第1放养区东部靠近水源的草地及裸地和第3放养区南部靠近狗牙根(Cynodon dactylon)群落及裸地等区域,受麋鹿种群内部转移影响,第2放养区内出现的麋鹿数量较少。裸地为保护区主要的土地利用类型,其面积占比最大,为34.97%;其次为林地,面积占比为25.63%;建筑用地面积占比最小,为0.43%。各类草地面积占比为18.08%,其中,芦苇(Phragmites australis)群落面积占比最大,为6.50%。集合层次分析法-地理信息系统(AHP-GIS)方法的接受者操作特征(ROC)曲线下的面积(AUC)值为0.788,大于0.75,可用于评价夏季麋鹿生境适宜性。适宜生境(包含最适宜生境、适宜生境和较适宜生境)主要位于核心区的水域、裸地、林地、芦苇群落和低草地等区域,其中,麋鹿最适宜生境(约235.87 hm²)占保护区总面积的8.85%,主要分布在第2核心区北部和第3核心区中南部等区域;较适宜生境(约965.09 hm²)面积占比最大,为36.19%;不适宜生境(包含较不适宜生境和最不适宜生境,约862.17 hm²)占总面积的32.33%,主要分布在第1放养区西部和第3放养区中部以北等区域。保护区夏季空间容纳量约为894头;芦苇生物量最高,为680.15 g/m²,碱蓬(Suaeda glauca)粗蛋白和粗脂肪质量分数均最高,分别为10.53%、3.07%,狼尾草(Pennisetum alopecuroides)的粗纤维含量最高,各类草本植物可提供的总能量为2.856×10⁹ kJ,相应的营养容纳量约为131头。【结论】保护区现有麋鹿8 216头,远超生态容纳量;将第2核心区部分麋鹿转移至第3核心区开展植被恢复及水系清淤疏浚等措施已取得较好成效。未来应进一步提升保护区麋鹿生境适宜性等级,同时增加雄性麋鹿占比以降低种群增长率,并在深入研究麋鹿潜在生境适宜区域基础上,建立新的分群保护区,缓解现有保护区的生态容纳压力。

【Objective】This study evaluated the habitat suitability for milu(Elaphurus davidianus)and estimated its ecological capacity, aiming to provide a scientific basis for regulating milu population structure and restorating their habitat to better.【Method】Taking Dafeng Milu National Nature Reserve in Jiangsu Province as the research site, this study utilized high-resolution unmanned aerial vehicle (UAV) technology as an alternative to traditional line-transect and quadrat survey methods to collect milu occurrence points data and generate land-use classification maps. Ten habitat evaluation factors were selected, and analytic hierarchy process (AHP) was applied to determine their weights. Using ArcGIS software for weighted overlay analysis, the summer habitat distribution map of milu across different suitability grades was generated. The summer ecological carrying capacity of milu was estimated by combining the area proportions of different habitat grades with the nutritional content of herbaceous plants.【Result】Milu population in the reserve are primarily identified in grassland and bareland near water sources in the eastern part of the first grade stocking area, as well as in areas adjacent to Cynodon dactylon community and bareland in the southern part of the third grade stocking area. Due to internal population transfers, fewer milu are observed in the second grade stocking area. Bareland is the dominant land-use type, covering 34.97% of the reserve, followed by woodland (25.63%), while construction land account for the smallest proportion (0.43%). Grassland collectively occupy 18.08%, with Phragmites australis community being the largest (6.50%). The area under the curve (AUC) of receiver operating characteristic (ROC) for AHP-GIS model is 0.788 (> 0.75), confirming its applicability for evaluating summer habitat suitability. Suitable habitats (including high suitable, suitable, and low suitable habitats) are predominantly located in core areas encompassing water source, bareland, woodland, Phragmites australis community, and low grassland. High suitable habitats (about 235.87 hm², 8.85% of the reserve) are concentrated in the northern part of the second grade core area and the central-southern part of the third grade core area. Low suitable habitats (about 965.09 hm², 36.19%) represent the largest proportion; Unsuitable habitats (containing low unsuitable habitat and unsuitable habitat, about 862.17 hm², 32.33% of the reserve) are mainly distributed in the western part of the first grade stocking area and the northern-central part of the third grade stocking area. The estimated summer spatial carrying capacity is approximately 894 individuals. Phragmites australis community exhibit the highest biomass (680.15 g/m²), Suaeda glauca have the highest crude protein (10.53%) and crude fat (3.07%) contents, and Pennisetum alopecuroides show the highest crude fiber content. The total energy provided by herbaceous plants is 2.856×10⁹ kJ, corresponding to a nutritional carrying capacity of approximately 131 individuals.【Conclusion】The current population of milu in the reserve has reached 8 216 individuals, significantly exceeding the ecological carrying capacity; The translocation of a portion of milu from second grade core area to third grade core area, combined with vegetation restoration and the dredging of water systems, has yielded significant and positive outcomes. Future recommendations include enhancing the habitat suitability level for milu within the reserve, increasing the proportion of male milu to moderate population growth rates. Additionally, based on thorough research into potential habitat suitability areas, the establishment of new sub-population reserves will help alleviate the current ecological capacity pressure on the existing reserve.