Abstract
Background: Climate change is driving ecosystem shifts, which has implications for tropical forest system function and productivity.
Aim: To investigate Amazon forest dynamics and test for compositional changes between 1985 and 2005 across different plant groups.
Methods: Tree census data from 46 long-term RAINFOR forest plots in Amazonia for three climate-functional groups were used: dry-affiliate, climate-generalist and wet affiliate. Membership of each group was ascribed at genus level from the distribution of individuals across a wet-dry gradient in Amazonia, and then used to determine whether the proportions of these functional groups have changed over time, and the direction of any change.
Results: In total, 91 genera, representing 59% of the stems and 18% of genera in the plots, were analysed. Wet-affiliates tended to move from a state of net basal area gain towards dynamic equilibrium, defined as where gain approximate to loss, governed by an increase in loss rather than a decrease in growth and mainly driven by plots in north-west Amazonia, the wettest part of the region. Dry-affiliates remained in a state of strong net basal area gain across western Amazonia and showed a strong increase in stem recruitment. Wet-affiliates and climate-generalists showed increases in stem mortality, and climate-generalists showed increased stem recruitment, resulting in overall equilibrium of stem numbers.
Conclusions: While there were no significant shifts in most genera, the results suggest an overall shift in climate-functional forest composition in western Amazonia away from wet-affiliates, and potential for increased forest persistence under projected drier conditions in the future.
Original language | English |
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Pages (from-to) | 267-279 |
Number of pages | 13 |
Journal | Plant Ecology & Diversity |
Volume | 7 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2014 |
Keywords
- climate trends
- forest composition
- moisture affiliation
- moisture seasonality
- tropical forest
- LONG-TERM PLOTS
- TROPICAL FORESTS
- CARBON-DIOXIDE
- RAIN-FOREST
- DROUGHT SENSITIVITY
- SPATIAL-PATTERNS
- ELEVATED CO2
- TREE
- IMPACTS
- BIOMASS