Table_4_Population status, habitat preferences and predictive current and future distributions of three endangered Silene species under changing climate.docx

One of the most crucial steps in the practical conservation of endangered endemic mountain plants is to address their population size status and habitat requirements concurrently with understanding their response to future global warming. Three endangered Silene species—Silene leucophylla Boiss., S. schimperiana Boiss., and S. oreosinaica Chowdhuri—in Egypt were the focus of the current study. These species were examined for population status change, habitat quality variables (topography, soil features, and threats), and predictive current and future distributions. To find population size changes, recent field surveys and historical records were compared. Using Random Forest (RF) and Canonical Correspondence Analysis (CCA), habitat preferences were assessed. To forecast present-day distribution and climate change response, an ensemble model was used. The results reported a continuous decline in the population size of the three species. Both RF and CCA addressed that elevation, soil texture (silt, sand, and clay fractions), soil moisture, habitat-type, chlorides, electric conductivity, and slope were among the important variables associated with habitat quality. The central northern sector of the Saint Catherine area is the hotspot location for the predictive current distribution of three species with suitable areas of 291.40, 293.10, and 58.29 km2 for S. leucophylla, S. schimperiana, and S. oreosinaica, respectively. Precipitation-related variables and elevation were the key predictors for the current distribution of three Silene species. In response to climate change scenarios, the three Silene species exhibited a gradual contraction in the predictive suitable areas with upward shifts by 2050 and 2070. The protection of these species and reintroduction to the predicted current and future climatically suitable areas are urgent priorities. Ex-situ conservation and raised surveillance, as well as fenced enclosures may catapult as promising and effective approaches to conserving such threatened species.

濒危特有山地植物的实际保护工作中，最为关键的步骤之一，是同步明确其种群规模现状与栖息地需求，并解析它们对未来全球变暖的响应。本研究以埃及境内的3种濒危蝇子草属（Silene）物种为研究对象：白叶蝇子草（Silene leucophylla Boiss.）、施姆佩尔蝇子草（S. schimperiana Boiss.）与奥雷西纳蝇子草（S. oreosinaica Chowdhuri）。针对上述物种，本研究开展了种群状态变化、栖息地质量变量（地形、土壤特征与威胁因子）以及当前与未来分布预测的相关考察。为明确种群规模的变化趋势，研究对比了近期野外调查数据与历史记录资料。研究采用随机森林（Random Forest, RF）与典范对应分析（Canonical Correspondence Analysis, CCA）对物种的栖息地偏好进行了评估。为预测当前分布格局及其对气候变化的响应，本研究采用了集成模型。研究结果显示，3个物种的种群规模均呈现持续下降趋势。RF与CCA分析均表明，海拔、土壤质地（粉粒、砂粒与黏粒占比）、土壤含水量、栖息地类型、氯化物含量、电导率及坡度，均为与栖息地质量密切相关的重要影响因子。3个物种的当前适宜分布区热点位于圣凯瑟琳地区中北部片区，其中白叶蝇子草、施姆佩尔蝇子草与奥雷西纳蝇子草的适宜分布面积分别为291.40、293.10与58.29 km²。与降水相关的环境变量与海拔，是决定3种蝇子草属物种当前分布的关键预测因子。在气候变化情景下，3种蝇子草属物种的预测适宜分布区将逐渐收缩，并在2050年与2070年发生向上迁移。对上述物种进行保护，并将其重新引入预测的当前与未来气候适宜区，是当前的紧迫优先事项。迁地保护、加强监测以及围栏封育，有望成为保护这类濒危物种的高效可行手段。