Tropical forests store large amounts of carbon in tree biomass, although the environmental controls on forest carbon stocks remain poorly resolved. Emerging airborne remote sensing techniques offer a powerful approach to understand how aboveground carbon density (ACD) varies across tropical landscapes. In this study, we evaluate the accuracy of the Carnegie Airborne Observatory (CAO) Light Detection and Ranging (LiDAR) system to detect top-of-canopy tree height (TCH) and ACD across the Osa Peninsula, Costa Rica. LiDAR and field-estimated TCH and ACD were highly correlated across a wide range of forest ages and types. Top-of-canopy height (TCH) reached 67 m, and ACD surpassed 225 Mg C ha-1, indicating both that airborne CAO LiDAR-based estimates of ACD are accurate in tall, high-biomass forests and that the Osa Peninsula harbors some of the most carbon-rich forests in the Neotropics. We also examined the relative influence of lithologic, topoedaphic and climatic factors on regional patterns in ACD, which are known to influence ACD by regulating forest productivity and turnover. Analyses revealed a spatially nested set of factors controlling ACD patterns, with geologic variation explaining up to 16% of the mapped ACD variation at the regional scale, while local variation in topographic slope explained an additional 18%. Lithologic and topoedaphic factors also explained more ACD variation at 30-m than at 100-m spatial resolution, suggesting that environmental filtering depends on the spatial scale of terrain variation. Our result indicate that patterns in ACD are partially controlled by spatial variation in geologic history and geomorphic processes underpinning topographic diversity across landscapes. ACD also exhibited spatial autocorrelation, which may reflect biological processes that influence ACD, such as the assembly of species or phenotypes across the landscape, but additional research is needed to resolve how abiotic and biotic factors contribute to ACD variation across high biomass, high diversity tropical landscapes.
The Institute of Artic and Alpine Research, University of Colorado, Boulder, CO, 80303, United States of America;Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, United States of America;National Center for Atmospheric Research, Advanced Study Program, Boulder, Colorado, 80307, United States of America;Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, United States of America;Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, United States of America;Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, United States of America;Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, United States of America;Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, 06269, United States of America;The Institute of Artic and Alpine Research, University of Colorado, Boulder, CO, 80303, United States of America;Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, 1010, Austria;Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, 1010, Austria;Instituto Tecnológico de Costa Rica, Escuela de Ingenieria Forestal, Cartago, Costa Rica;Instituto Tecnológico de Costa Rica, Escuela de Ingenieria Forestal, Cartago, Costa Rica;The Institute of Artic and Alpine Research, University of Colorado, Boulder, CO, 80303, United States of America
Recommended Citation:
Philip Taylor,Gregory Asner,Kyla Dahlin,et al. Landscape-Scale Controls on Aboveground Forest Carbon Stocks on the Osa Peninsula, Costa Rica[J]. PLOS ONE,2015-01-01,10(6)