Understanding Long-Term Savanna Vegetation Persistence across Three Drainage Basins in Southern Africa
Understanding Long-Term Savanna Vegetation Persistence across Three Drainage Basins in Southern Africa
复制标题
DOI：
10.3390/rs10071013
复制
发表时间：
2018-07-01
期刊：
影响因子：
5
通讯作者：
Waylen, Peter
中科院分区：
文献类型：
--
作者：
Bunting, Erin L.;Southworth, Jane;Waylen, Peter
在南部非洲的稀树草原景观中，人们与环境紧密相连，这意味着景观的改变将影响生计和社会生态发展。鉴于人类与环境的联系，有必要进一步了解稀树草原植被动态的驱动因素，并在气候变化日益加剧的情况下，更好地了解植被与气候的关系。先进甚高分辨率辐射计 (AVHRR) 和中分辨率成像光谱辐射计 (MODIS) 衍生的植被指数的月度时间序列早在 20 世纪 80 年代就已推出，有望对复杂的植被-气候动态进行大规模量化，并对与全球环境变化相关的景观变化进行区域分析。在这项工作中，我们采用基于时间序列的分析来检查随时间变化和跨显着降水梯度的景观植被绿化模式。在这项研究中，我们表明，气候引起的归一化植被指数（NDVI；即退化或生物量下降）的减少对南部非洲的宽多、奥卡万戈和赞比西流域产生了巨大的空间和时间影响。我们得出的结论是，随着时间的推移，每个季节温度的升高都会导致可用土壤湿度的变化。所有三个流域生态系统动态的变化导致了景观绿化模式的全系统变化。
Across savanna landscapes of southern Africa, people are strongly tied to the environment, meaning alterations to the landscape would impact livelihoods and socioecological development. Given the human-environment connection, it is essential to further our understanding of the drivers of savanna vegetation dynamics, and under increasing climate variability, to better understand the vegetation-climate relationship. Monthly time series of Advanced Very High-Resolution Radiometer (AVHRR)- and Moderate Resolution Imaging Spectroradiometer (MODIS) derived vegetation indices, available from as early as the 1980s, holds promise for the large-scale quantification of complex vegetation-climate dynamics and regional analyses of landscape change as related to global environmental changes. In this work, we employ time series based analyses to examine landscape-level vegetation greening patterns over time and across a significant precipitation gradient. In this study, we show that climate induced reductions in Normalized Difference Vegetation Index (NDVI; i.e., degradation or biomass decline) have had large spatial and temporal impacts across the Kwando, Okavango, and Zambezi catchments of southern Africa. We conclude that over time there have been alterations in the available soil moisture resulting from increases in temperature in every season. Such changes in the ecosystem dynamics of all three basins has led to system-wide changes in landscape greening patterns.