Kumar Devendra, Rawat Sandeep
G.B. Pant National Institute of Himalayan Environment (NIHE), Sikkim Regional Centre, Gangtok, Sikkim, India.
Environ Sci Pollut Res Int. 2022 Oct;29(48):72431-72444. doi: 10.1007/s11356-022-20412-w. Epub 2022 May 7.
It is vital to understand the distribution area of a threatened plant species for its better conservation and management planning. Satyrium nepalense (family: Orchidaceae) is a threatened terrestrial orchid species with valuable medicinal and nutritional properties. The survival of S. nepalense in wild conditions has been challenged by increasing global surface temperature. Hence, understanding the impact of climate change on its potential distribution is crucial to conserve and restore this species. In present study, Maxent species distribution modeling algorithm was used to simulate the current distribution of S. nepalense in India and predict the possible range shift in projected future climate scenarios. A set of 19 bioclimatic variables from WorldClim database were used to predict the potential suitable habitats in current climatic condition and four Representative Concentration Pathway (RCP 2.6, 4.5, 6.0, and 8.5) scenarios by integrating five General Circulation Models (GCMs) for future distribution modeling of species for the years 2050 and 2070. Furthermore, change analysis was performed to identify the suitable habitat in current and future climate for delineating range expansion (gain), contraction (loss), and stable (no change) habitats of species. The Maxent model predicted that ~ 2.38% of the geographical area in India is presently climatically suitable for S. nepalense. The key bioclimatic variables affecting the distribution of studied species were the mean temperature of warmest quarter, mean temperature of wettest quarter, precipitation of warmest quarter, and temperature seasonality. Under future climate change scenarios, the total suitable habitat of S. nepalense will increase slightly in the Himalayan region and likely to migrate towards northward, but in the Western Ghats region, the suitable areas will be lost severely. The net habitat loss under four RCP scenarios was estimated from 26 to 39% for the year 2050, which could further increase from 47 to 60% by the year 2070. The finding of the predictive Maxent modeling approach indicates that warming climates could significantly affect the potential habitats of S. nepalense and hence suitable conservation measures need to be taken to protect this threatened orchid species in wild conditions.
了解受威胁植物物种的分布区域对于更好地进行保护和管理规划至关重要。尼泊尔鸟舌兰（科：兰科）是一种受威胁的地生兰花物种，具有宝贵的药用和营养特性。全球地表温度上升对尼泊尔鸟舌兰在野外条件下的生存构成了挑战。因此，了解气候变化对其潜在分布的影响对于保护和恢复该物种至关重要。在本研究中，使用最大熵物种分布建模算法来模拟尼泊尔鸟舌兰在印度的当前分布，并预测在未来预测气候情景下可能的范围变化。利用来自WorldClim数据库的一组19个生物气候变量，通过整合五个通用环流模型（GCM），预测当前气候条件下的潜在适宜栖息地以及四个代表性浓度路径（RCP 2.6、4.5、6.0和8.5）情景下该物种在2050年和2070年的未来分布情况。此外，进行了变化分析，以确定当前和未来气候中的适宜栖息地，从而划定该物种的范围扩张（增加）、收缩（减少）和稳定（无变化）栖息地。最大熵模型预测，目前印度约2.38%的地理区域在气候上适合尼泊尔鸟舌兰生长。影响该研究物种分布的关键生物气候变量是最暖季度的平均温度、最湿季度的平均温度、最暖季度的降水量和温度季节性。在未来气候变化情景下，尼泊尔鸟舌兰的适宜栖息地总面积在喜马拉雅地区将略有增加，并可能向北迁移，但在西高止山脉地区，适宜区域将严重丧失。2050年四个RCP情景下的净栖息地丧失估计为26%至39%，到2070年可能进一步增加到47%至60%。预测性最大熵建模方法的研究结果表明，气候变暖可能会显著影响尼泊尔鸟舌兰的潜在栖息地，因此需要采取适当的保护措施来保护这种在野外受威胁的兰花物种。
