The unifying element of the CTFS network is the large-scale Forest Dynamics Plot, one or more of which is managed with in-country partners -- universities, government agencies, and non-governmental organizations -- at each of the 17 sites in which CTFS is active.
Perhaps the largest and most comprehensive units of study employed in tropical forest ecology, the Forest Dynamics Plots are sufficiently large to encompass the astonishing diversity of tropical forests, and to capture statistically significant numbers of rare species – allowing scientists to detect patterns and processes in tropical forest communities that would otherwise be impossible to recognize.
Forest Dynamics Plots are unique because of their large size and intensive tree sampling protocol. During a plot census, every tree over one centimeter in diameter is marked, measure, plotted on a map, and identified on the species level. Plots are typically 50 hectares in size, but can range from 15 to 52 hectares depending on the species diversity. As many as 360,000 trees are monitored in a single plot. During a plot recensus, which occurs approximately every five years, every tree is re-measured, dead trees noted, and young trees added to the plots' database. The information gathered from these recensuses allows investigations into forest dynamics - how forests change.
CTFS Forest Dynamics Plots are generating basic information that has eluded scientists for years, and provide an effective metric of forest health, regeneration and growth.
- Integrative Information - CTFS researchers combine this complex understanding of natural forest communities with socioeconomic, silvicultural, and ecological information generated in and around the Forest Dynamic Plots. This knowledge is then applied to better inform and improve forest management and conservation. These efforts have so far generated sustainable timber management plans, analyses of forest responses to climate change, and the design and implementation of forest restoration programs.
- Longevity – CTFS’ long-term monitoring – extending back 25 years in some locations - provides unique time-sequenced information on natural and man-made environmental changes, and allows researchers to track the impact of regional disturbances such as hurricanes and landslides, global climate events such as El Niño / Southern Oscillation, and long-term climate change on tropical ecosystems.
- Global compatibility – Since identical methodologies are employed at all sites, the collective network of information allows scientists a unique opportunity to address broad questions on regional or global scales, and to detect large-scale changes in forest structures and dynamics. The CTFS network may serve as an early warning system for changes in global ecosystems as a result of climate change and other factors.]
For detail methodology:
Condit, R. G. 1997. Field guide for tropical forest census plots: methods and results from Barro Colorado Island, Panama and a comparison with other plots. R.G. Landes, Austin.
Rolando Pérez, Salomón Aguilar, Richard Condit, Robin Foster, Stephen Hubbell, Suzanne Lao. 2005. Metodología empleada en los censos de la parcela de 50 hectareas de la isla de Barro Colorado, Panama. [Methods for the census of the 50-ha plot on Barro Colorado Island, Spanish version.] Online Publication http:// ctfs.si.edu/onlinepubs/ParcelaBCIMetodo2005.pdf