Abstract ID: 177

Floristic and functional affiliations of woody plants with climate in western Amazonia

Determining which plant groups are constrained by which environmental variables can contribute to our understanding of how forest composition may be changing now, and under future climate. We investigate the direct relationship between the relative abundance of lowland rainforest woody plant genera and the precipitation regime along the north - south climate gradient of the western Amazon. Floristic data from 39 x 0.1-ha Gentry plots across the western Amazon and precipitation data from CRU (Climate Research Unit) were used to test for correlations between plant abundance and derived dry-season variables. Moisture preference was then assessed in terms of pioneer and shade-tolerant life history strategy. The results revealed significant associations between the distribution of plant relative abundances and seasonal precipitation variables and suggested that 34% of genera analysed were strongly affiliated with either wet or dry conditions. The results also suggest that moisture variable seasonality influences community composition in terms of the life history trade-off between shade tolerance and pioneer ranking. Community structure in wet forests may be more vulnerable to future increases in moisture stress if shade tolerant trees are also drought intolerant. This work has provided a quantified relationship between 91 common genera and the seasonal rainfall regime, and a novel dry season metric.

Session:  Biodiversity - Permanent plot networks for inventory of biodiversity and carbon stocks: integrating taxonomic and ecosystem objectives.

Presentation Type:  Poster