The timing and development of leaf canopies represent an essential part of the adaptive strategy of deciduous trees and herbs. This canopy phenology is an extremely sensitive indicator of the many factors such as climate, soil moisture, and land use that affect natural vegetation. At coarse spatial scales, the phenology of natural vegetation is strongly correlated with climate. In order to understand how phenology may be used as an indicator of climate change it is necessary to establish first the baseline variation in phytophenological rhythms under current types of environmental variation. Multitemporal observations of phenology made from satellite platforms provide a unique way of assessing ecosystem dynamics at a variety of spatial and temporal scales and thus provide a crucial link between local-scale studies and global data sets. This study will use multitemporal satellite, climate, and ground reference data to document and model regional canopy phenology in several different extensive, but contrasting, plant communities in south-central Africa. The project will use field data and satellite imagery to reveal contrasts in regional-scale phenology and to validate the satellite measurements. Increased climatic variation under enhanced greenhouse conditions is expected to produce severe disruptions in the annual life cycles of many organisms. The relationship of current phenological rhythms to the climate at the present time may provide clues as to the probable effects of future climate change on regional vegetation types. In order to understand how phenology may be used as an indicator of global change, this study will establish baseline variation in phytophenological rhythms under current levels of climate variation.
