Michael Toomey

Remotely sensed heat anomalies linked with Amazonian forest biomass declines

The occurrence of two major Amazonian droughts in 2005 and 2010 underscores the need for improved understanding of how drought affects tropical forest. During both droughts, MODIS land surface temperature data detected anomalously high daytime and nighttime canopy temperatures throughout drought-affected regions. Daytime thermal anomalies explained 38.6% of the variability in the reduction of aboveground living biomass (p < 0.01; n = 17) in drought-affected forest sites. Multivariate linear models of heat and moisture stress explained a greater proportion of the variability, at 65.1% (p < 0.01; n = 17), providing substantively greater explanatory power than precipitation-only models. Our results suggest that heat stress played an important role in the two droughts and that models should incorporate both heat and moisture stress to predict drought effects on tropical forests.

Improving Household Surveys Through Computer-Assisted Data Collection Use of Touch-Screen Laptops in Challenging Environments

Data on land use change and socioeconomic dynamics in developing countries are often collected via paper-and-pencil interviewing (PAPI). This article reviews a computer-aided personal interviewing (CAPI) methodology adopted for the fourth wave of a panel survey administered in a remote region of the Brazilian Amazon in 2009. Ruggedized touch-screen laptops were used to address challenges associated with survey administration in this setting as well as limitations associated with the PAPI method. The authors discuss hardware and software considerations, methodological innovations, and tests for mode effects on missing item response rates and enumerator learning effects.

Multi-Scale Sensor Fusion With an Online Application: Integrating GOES, MODIS, and Webcam Imagery for Environmental Monitoring

Webcam and satellite imagery are integral sensor web components, but there are few websites that directly synthesize these products. Additionally, websites as a means for reviewing multiple images in an organized way and for analyzing time-series imagery have not been fully explored. This paper describes how web applications can facilitate review of image archives for multi-scale sensor data fusion, with a test case of an automatic panning camera at the highest peak on Santa Cruz Island (in Channel Islands National Park off the Santa Barbara, CA coast) and MODIS and GOES-11 satellite imagery. We developed the application PanOpt (http://zulu.geog.ucsb.edu/panopt/index.html) for filtering this image database and outputting selected images as a static matrix or as an animation. On-demand product generation includes time-series charts and scatter plots of image metrics for regions of interest, with data markers linked to views of corresponding satellite and camera imagery via event-based web scripting. This is useful not only for exploratory analysis but is well suited for pedagogical applications and imparting a greater synoptic understanding of environmental phenomena. Demonstration of this websites utility includes multi-modal characterization of clouds as well as ground- and satellite-based plant phenology time-series. With this tool, the quantitative and qualitative aspects of image exploration are synergistic, making it easier to discern underlying trends and anomalies and to identify directions for further analysis.

Detecting and interpreting secondary forest on an old Amazonian frontier

Land uses that replace tropical forests are important determinants of terrestrial carbon storage and biodiversity. This includes secondary forest growth after deforestation, which has been integrated into the REDD+ (Reducing Emissions from Deforestation and Forest Degradation) concept as a means to enhance current forest carbon stocks. Incorporating secondary forest into climate change mitigation efforts requires both accurate measurements and a means to target interventions to achieve additionality. We demonstrate how remote sensing and household survey data can be combined to meet these requirements in ‘old frontiers’ of the Brazilian Amazon and introduce the idea that annual land-cover transitions − measured at the pixel level and over time − can serve as leading indicators of secondary forest regrowth. The patterns we observe are consistent with the suggested tension between equity and additionality in REDD+: the poorest households on the poorest quality lots already allow forest regeneration. Policy interventions to encourage regeneration are likely to have the greatest additional impact on higher quality lots owned by better capitalized households.