Climate change impacts on tropical forest phenology
Changes in the timing of seasonal life cycle events – phenology – have provided some of the strongest evidence of ecosystem responses to climate change. Yet the magnitude of response to warming (Wolkovich et al. 2012), our ability to make predictions across space, time, and species (Pau et al. 2011; Cook et al. 2012; Davies et al. 2013), and the functional consequences of phenological shifts (Cleland et al. 2012) remains uncertain.
Most of our understanding of climate change impacts on plant phenology is from temperate regions (Cook et al. 2012). There are few long-term records from tropical sites.
- Recent work using rare long-term data is examining how tropical forest phenology responds to climate variability across different timescales and growth forms (Pau et al. 2013, Pau et al. in prep).
- New monitoring of leaf and reproductive activity is beginning on the Big Island, Hawaii.
Monitoring the thermal environment of tropical forests
Tropical organisms exist in microclimates that are highly variable in space and time and not easily measured in natural environments. Most studies use air temperature measurements from sparse meteorological stations even though surface temperatures are known to deviate from air temperatures. This is in part because of the complex structure of tropical forests and the potential for organisms themselves to modify their own environment. In the case of plants, leaf temperature is linked to the water and surface energy balance of their microenvironment. Camera overlooking diverse forest canopy at
Barro Colorado Island (BCI), Panama
- Monitoring the thermal environment of a structurally and biologically complex forest canopy (5 minute 8-14um data from Barro Colorado Island, Panama) will help answer questions such as what is upper temperature limit of photosynthesis in tropical forests and how is canopy temperature related ecosystem functions such as carbon assimilation and phenology?
#HotMonkeys #40C (March 2015)
Managing forests for multiple ecosystem services
The loss of tropical forests simultaneously eliminates critical habitat for wildlife in the world’s most diverse locations and is the second largest contributor to anthropogenic greenhouse gas emissions. However, more immediate human needs motivate rapid deforestation in the tropics.
Although tropical deforestation is commonly attributed to complex interactions between various causes and underlying drivers, a recent global meta-analysis (Pau in review) showed widespread consensus that agriculture, increasingly linked to economic globalization, is the most common cause of tropical deforestation.
New research will use high-resolution satellite data paired with field surveys of agroforestry plots to quantify forest cover change and associated ecosystem functions along the margins of Bukit Barisan Selatan National Park (BBSNP) in Sumatra, Indonesia.
Pleiades-1A multispectral satellite image (0.5m)
along margins of BBSNP in Sumatra, Indonesia