气候变化对新疆雪岭云杉潜在适宜分布及生态位分化的影响

探究气候变化对天山森林植物潜在空间分布的影响及其模拟预测有助于揭示中尺度下植物分布格局对气候变化的适应对策和反馈机制，对促进干旱区山地森林生态系统的生物多样性保育和森林资源可持续管理有着重要的科学和实践意义。基于雪岭云杉的分布点数据和环境因子数据，利用最大熵(MaxEnt)模型、GIS工具及R软件估计其在基准气候(1970—2000年)及2050(2041—2060年)和2070(2061—2080年)时段基于RCPs气候情景下的潜在分布范围、空间格局变化及生态位分化。结果表明：(1)雪岭云杉在基准气候下的潜在分布与2019年秋季的NDVI植被覆盖变化基本保持一致，高适生分布区主要分布在东疆的哈密、巴里坤和伊吾，北疆主要分布在天山北坡、博格达山、北塔山和伊犁河谷，南疆主要分布在天山南坡。另外，在阿尔泰山南坡、塔城、裕民、托里、西昆仑山和小帕米尔山地也有分布。(2)限制雪岭云杉潜在分布的关键因子为降水(最干月降水量、最冷季降水量和降水季节性)和温度(最干季平均温度、年均温、等温性和气温年较差)、土壤剖面有效含水量、土壤碳密度及海拔，其累计贡献率之和达到87.28%。(3)2050和207...

Effects of climate change on potential distribution and niche differentiation of Picea schrenkiana in Xinjiang

Exploring the impact of climate change on the potentially spatial distribution of forest plants in Tianshan Mountain and its simulation and prediction can help to reveal the adaptation strategies and feedback mechanisms of plant distribution patterns to climate change at the mesoscale. It has important scientific and practical significance for promoting biodiversity conservation and sustainable management of forest resources in Arid Mountainous Forest Ecosystem. Based on the data of distribution points of Picea schrenkiana and environmental factors data, the maximum entropy (MaxEnt) model, GIS tools and R software were used to estimate the potential distribution range, spatial pattern changes and niche differentiation of P. schrenkiana under the reference climatic (1970-2000), Representative Concentration Pathways (RCPs) based climate scenarios in 2050 (2041-2060) and 2070 (2061-2080). The results showed that:(1) the potential distribution of P. schrenkiana in the reference climatic was basically consistent with the Normalized Difference Vegetation Index (NDVI) vegetation cover change in autumn of 2019. The high suitability distribution areas are mainly distributed in Hami, Balikun and Yiwu in Eastern Xinjiang, the north slope of Tianshan Mountain, Bogda Mountain, Beita Mountain and Yili Valley in Northern Xinjiang, and the south slope of Tianshan Mountain in Southern Xinjiang. In addition, it was also distributed in the southern slope of Altay Mountain, Tacheng, Yumin, Tuoli, Western Kunlun Mountain and little Pamirs mountain. (2) The key factors limiting the potential distribution of P. schrenkiana were precipitation (Precipitation of driest month, Precipitation of coldest quarter and Precipitation seasonality), temperature (Mean temperature of driest quarter, Annual mean temperature, Isothermality and Annual temperature range), soil profile available water capacity, soil carbon density, and altitude. Their cumulative contribution rate reached 87.28%. (3) In 2050 and 2070 periods, the suitable distribution range of P. schrenkiana showed no significant increasing trend, but the RCP6.0 scenario was more significant than the RCP2.6, with an increase of 3.33% and 3.47%, respectively; The low, middle and high suitable areas maintained relatively stable changes, the growth rates from RCP2.6 to RCP6.0 scenarios are about 1.78%, 1.26%, and 0.98%, respectively; and the center of gravity of suitable distribution areas showed a trend towards higher latitude and northeastward, but the change amplitude was not significant. (4) PCA analysis showed that the climate niche of P. schrenkiana was the most extensive in Southern Xinjiang, followed by Northern Xinjiang, and the narrowest in Eastern Xinjiang. Niche differentiation test indicated that there was no significant differentiation in the Northern, Southern and Eastern Xinjiang.