From plot to landscape scale: linking tropical biodiversity measurements across spatial scales

© The Ecological Society of America www.frontiersinecology.org I is widely recognized that land conversion, hunting, forest harvesting, and other human influences are depleting biodiversity. Yet the specific mechanisms through which human activities affect species at particular locations remain poorly characterized. This lack of understanding limits our ability to attribute changes in biodiversity observed at the local scale to processes operating over multiple scales, including local-scale human disturbances, regional-scale land-use change, or global-scale climate variability. Improved understanding of the biodiversity response to human and ecological influences operating over multiple spatial scales is crucial for identifying global trends, focusing conservation priorities, and enabling effective design of community-based conservation efforts. Networks for monitoring biodiversity are currently being discussed and implemented (Andelman and Willig 2004; Dobson 2005; Pereira and Cooper 2006; Teder et al. 2007). An immediate imperative is to assess progress toward the Convention on Biological Diversity’s 2010 goal to “reduce the rate of loss of biodiversity”. Existing monitoring networks and long-term plots for measuring biodiversity are generally not coordinated with standard measurement protocols and approaches (Pereira and Cooper 2006). Here, we suggest that monitoring strategies will be most effective in the long run if they monitor not only biodiversity at the plot level but also ecological and human processes that influence the observed biodiversity at multiple spatial scales. Such information facilitates analysis of causal linkages with the many climatic, ecological, and human factors that potentially influence observed biodiversity. This need raises an obvious question: what attributes should be monitored, and over what spatial extent, around plots? Answering this question requires linking plot-level measurements with processes operating over a range of spatial scales. This linkage across scales is generally not incorporated into biodiversity monitoring. Monitoring human disturbances at the local scale is essential for interpreting biodiversity trends. Observations of diurnal lemurs and human disturbance along CONCEPTS AND QUESTIONS