Assessing vulnerability and responses of forest edges to drought in the Brazilian Amazon

Izaya Numata, South Dakota State University, izaya.numata@sdstate.edu (Presenter)
Mark A. Cochrane, South Dakota State University, mark.cochrane@sdstate.edu
Jeppe Kjaergaard, South Dakota State University, jeppe.kjaergaard@sdstate.edu
Kul Khand, South Dakota State University, kul.khand@sdstate.edu
Sonaira Souza Silva, Federal University of Acre, sonairasilva@gmail.com

Recent severe droughts in Amazonia (2005 and 2010) have led to extensive damages to forest canopies and increased rates of tree mortality. More than 600,000 km2 of forest area were affected by the two droughts. In addition to drought, the Amazon forest has been increasingly disturbed by deforestation in recent decades, with remnant forests continuously being fragmented into smaller habitats. Fragmented forests suffer several biological and ecological changes due to edge effects, including desiccation, that exacerbate regional forest degradation. Drought impacts are expected to be larger and more severe in fragmented forest landscapes, especially near forest edges that dry more rapidly and intensely, however, the spatial scale of this phenomenon has not yet been quantified. As more frequent and extreme future drought events are predicted, more severe and extensive damages in regional ecosystems are expected as remnant forests become increasingly fragmented with ongoing Amazonian land cover changes. Forest edges may serve as early warning indicators of potential tipping points at which climate change-triggered drought conditions could cause serious ecological shifts in Amazonian ecosystems. Our approach is the following: 1) determine drought intensity and forest fragmentation metrics (landscape metrics) across the southern Brazilian Amazon (1998-2014); 2) conduct field studies of forest edges determined by drought intensity and forest fragmentation to examine vulnerability and responses of forest edges; 3) generate time series data of ET and vegetation indices from Landsat to assess regional canopy desiccation and its recovery from drought impacts; and 4) predict the future vulnerability of forest edges to drought based upon simulated future climate and land cover change scenarios. We present our preliminary results of Year 1 from analyses of climate-forest fragmentation interactions and forest inventory data collected in the southwestern Amazon.

Presentation Type:  Poster

Session:  Theme 4: Human influence on global ecosystems   (Mon 4:30 PM)

Associated Project(s): 

• Numata, Izaya: Assessing vulnerability and responses of forest edges to drought in Amazonia ...details

Poster Location ID: 86