Contrasting water-use strategies across tropical African and Latin American savannas

Savannas cover about 20% of the global surface and are the largest tropical biome. They are responsible for 30% of terrestrial primary productivity and 21% of global evapotranspiration. They occur over a variety of soil types, climatic envelopes and fire regimes, something which drives the megadiversity which exists in this biome. Despite this global importance, they have been understudied relative to other tropical biomes, especially rain forests.

Over millions of years, diverse floras in different savanna regions evolved to cope with seasonal drought. In some regions, such as Africa, trees manage seasonal drought through deciduousness, and in other regions such as South America and Australia, plants are predominantly evergreen and carefully manage water use over an extended dry season. How savanna plants respond to shifts in the rainfall patterns and increased temperatures will likely be related to their phenological and water use strategies.

But with regions having such substantive differences in phenology that they can be observed from space, means we should not expect all savannas to respond similarly to environmental change. We still know relatively little about how the plants in these savannas function and until we understand the foundation for such regional differences in plant water use and phenological strategies and integrate this into modelling it will be impossible to predict how ecosystems respond to changing rainfall and temperature patterns.

This project aims to address differences in plant water use strategies across these savanna ecosystems, mainly investigating key plant functional traits and leaf phenology in intercontinental savannas.