Braun-Blanquet cover scores as a proxy for detailed measurement of community structure.
The selective harvest of trees and the cutting down of forests for human land uses continue to negatively impact the quality and extent of the world’s tropical forests. More effective strategies for their conservation within increasingly human-modified landscapes require detailed information on understorey vegetation changes collected across large areas and at multiple points in time. The sampling of key ecological descriptors of understorey plant community composition and structure, however, is often impracticable due to the high complexity and diversity intrinsic to tropical forests. For example, leaf area index (LAI) and above-ground biomass (AGB) can only really be quantified through destructive harvesting of vegetation, which is disproportionately labour- and time-intensive.
In a new manuscript led by Timm Döbert in the Journal of Vegetation Science, we explore efficient and effective surrogate metrics for estimating LAI and AGB. Using understorey biomass harvest data collected from over 300 vegetation plots across a rainforest disturbance gradient at the Stability of Altered Forest Ecosystems (SAFE) project in Malaysian Borneo, we demonstrate the application of the widely applied Braun-Blanquet cover-abundance approach as a proxy for LAI and AGB.
Overall, our results indicate a remarkably simple and accurate logarithmic scaling for LAI consistent across most plant growth forms, yet a more complex scaling relationship between cover scores and AGB. We conclude that the findings of this study should be broadly applicable to other ecosystems due to the heterogeneity of plant communities from primary rainforest over repeatedly logged rainforest to mature oil palm plantation included in this work.
Read more by downloading the paper here.
Döbert, T.F.D., Webber, B.L., Sugau, J.B., Dickinson, K.J.M. & Didham, R.K. (2015) Can leaf area index and biomass be estimated from Braun-Blanquet cover scores in tropical forests? Journal of Vegetation Science (In press; DOI: 10.1111/jvs.12310).