What determines primary productivity and its allocation across the tropical forest biome?
Yadvinder Malhi, University of Oxford, UK | @ymalhi
Tropical forests have long been described as the most productive natural biomes on Earth, but the patterns and biogeography of that productivity have rarely been described. In addition, how that productivity is shared been canopies, wood and roots is poorly understood. Such understanding is needed if we are to understand how tropical forests are responding to the global change. Here I explore how productivity and allocation vary across the tropical forest biome, drawing in particular on data from the GEM (Global Ecosystems Monitoring) Network. I explore the roles of soil, climate and biogeography in shaping these patterns, and determine how well satellite remote sensing is able to capture this spatial variation.
What is the tropical dry forest biome and where is it found?
Kyle Dexter, University of Edinburgh, UK
Tropical dry forests (TDFs) are distinct from tropical rain forests in their strong seasonality to water availability with downstream implications for phenology, carbon dynamics and other biogeochemical cycles. TDFs are distinct from savannas in that they rarely experience fire and are populated by many species that are in fact intolerant of fire. While these distinctions seem clear, in fact, various global categorisations of tropical vegetation misidentify and mis-map TDFs, including classifying TDFs as deserts or savannas. This talk will cover current views on what TDFs are, whether or not they should be represented as a distinct biome in global vegetation modelling and where they are found. These ideas are placed in the broader context of variation in vegetation form and function across the dry tropics.
The role of fire, frost, and fire suppression in tropical savanna structure
Natashi Pilon, Universidade Estadual de Campinas (UNICAMP), Brazil | @natashipilon
Fire, frost and also fire suppression are important drivers of plant communities in tropical grasslands and savannas. However, plant community responses to these disturbances are largely unknown in Neotropical savanna ecology, especially for plant species of the ground layer – a key component for savanna dynamics. Our studies have shown that although both fire and frost reduce plant biomass, their effects on the ground layer of Neotropical savannas are in some way antagonistic. We also found that these ecosystems are extremely resilient to both. In a scenario of fire suppression, however, even if sporadic frosts occur, woody encroachment tends to happen. With biomass increase, the ground layer of these ecosystems loses biodiversity and resilience.