Spatial and temporal heterogeneity of phenology patterns in Kruger National Park, South Africa: different drivers for different areas

摘要

In this paper we explore the spatio-temporal variation of vegetation greenness and the underlying causal processes in a southern African savanna region. From the AVHRR NDVI time series we derived the following phenological metrics for the period 1985-1999: start, length and end of wet season, NDVI_(max) and seasonal ∑NDVL We used a spatio-temporal clustering technique to find the most probable phenological clusters in space and time. All phenological metrics had high temporal and spatial variability, and we tested how well temperature, rainfall, soil and tree cover explained the observed patterns. Phenology metrics models which included tree cover and/or soil sand % together with rainfall received the best support. This highlights the importance of developing a finer scale spatially explicit rainfall-vegetation model in order to infer how biodiversity will be affected by climate change.