Abstract

Climate change and anthropogenic activity in the Republic of Buryatia aggravate the processes of desertification and land degradation. The territory of Buryatia was zoned according to the aridity index based on ENVIREM climate data with a high spatial resolution. Long-term changes in the vegetation cover in arid and humid zones are quantitatively assessed based on a combined study of the time series of the normalized-difference vegetation index (NDVI) with the Advanced Very High Radiation Radiometer (AVHRR), meteorological series of the NCEP/NCAR Reanalysis data set, and field studies. Maps of the spatial distribution of NDVI linear trends and precipitation for 1982–2015 (with the differentiation of the wet (1982–1999) and dry periods (2000–2015)) have been constructed. During the wet period, positive NDVI trends are observed for almost the entire republic, while the dry period is characterized by a significant increase in negative trends of the vegetation index. A positive correlation between the Selyaninov hydrothermal coefficient and NDVI is observed for intermountain steppe basins, while it is negative for forest landscapes. The dynamics of the NDVI for steppe vegetation is more dependent on precipitation, while the dynamics of the NDVI for forests is more significantly correlated with temperature. Reforestation, postpyrogenic succession, the bushing of fallow lands, and other factors determine the growth in the NDVI. Negative NDVI trends are characteristic of steppe ecosystems with low precipitation and forest ecosystems exposed to felling and fires.

中文翻译：

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布里亚特共和国干旱生态系统的时空变异性评估

摘要

布里亚特共和国的气候变化和人类活动加剧了荒漠化和土地退化的进程。根据基于ENVIREM气候数据的干旱指数，以高空间分辨率对布里亚特共和国的领土进行了分区。干旱和湿润地区植被覆盖的长期变化是基于对归一化植被指数（NDVI）和先进极高辐射辐射仪（AVHRR）的气象序列的时间序列的综合研究而定量评估的。 NCEP / NCAR重新分析数据集和现场研究。绘制了1982-2015年NDVI线性趋势和降水的空间分布图（随着湿润（1982-1999）和干旱时期（2000-2015）的差异）。在潮湿的时期 几乎整个共和国都观察到NDVI呈正趋势，而干旱期的特征是植被指数的负趋势显着增加。山间草原盆地的Selyaninov热液系数与NDVI之间呈正相关，而森林景观则呈负相关。草原植被NDVI的动态更依赖于降水，而森林NDVI的动态更与温度相关。植树造林，热原后演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是降水量低的草原生态系统和遭受砍伐和火灾的森林生态系统的特征。而干旱期的特征在于植被指数的负趋势显着增加。山间草原盆地的Selyaninov热液系数与NDVI之间呈正相关，而森林景观则呈负相关。草原植被NDVI的动态更依赖于降水，而森林NDVI的动态更与温度相关。植树造林，热原后演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是降水量低的草原生态系统和遭受砍伐和火灾的森林生态系统的特征。而干旱期的特征在于植被指数的负趋势显着增加。山间草原盆地的Selyaninov热液系数与NDVI之间呈正相关，而森林景观则呈负相关。草原植被NDVI的动态更依赖于降水，而森林NDVI的动态更与温度相关。植树造林，热原后演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是降水量低的草原生态系统和遭受砍伐和火灾的森林生态系统的特征。山间草原盆地的Selyaninov热液系数与NDVI之间呈正相关，而森林景观则呈负相关。草原植被NDVI的动态更依赖于降水，而森林NDVI的动态更与温度相关。植树造林，热原后演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是降水量低的草原生态系统和遭受砍伐和火灾的森林生态系统的特征。山间草原盆地的Selyaninov热液系数与NDVI之间呈正相关，而森林景观则呈负相关。草原植被NDVI的动态更依赖于降水，而森林NDVI的动态更与温度相关。植树造林，热原后演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是降水量低的草原生态系统和遭受砍伐和火灾的森林生态系统的特征。发烧后的演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是低降水量草原生态系统和遭受砍伐和大火的森林生态系统的特征。发烧后的演替，休耕地的灌木丛以及其他因素决定了NDVI的增长。NDVI的负趋势是低降水量草原生态系统和遭受砍伐和大火的森林生态系统的特征。