Ecologists Stephen Hubbell and Robin Foster established a 50-hectare permanent forest plot on Barro Colorado Island (BCI) in Panama to repeatedly measure and map all trees above a set size. This created a standardized way to track tree growth, death, and recruitment over decades. The BCI plot became the model that later ForestGEO sites in the Amazon and Southeast Asia would follow.
ForestGEO’s institutional history traces the first long-term site to Barro Colorado Island, where intensive tree-census methods were pioneered and then replicated elsewhere. These methods involve tagging, identifying, mapping, and measuring every free-standing woody stem above a minimum diameter, then repeating the census on a regular cycle. This approach made it possible to compare forests across regions using the same field protocol.
A second major forest dynamics plot was initiated at Pasoh Forest Reserve in Peninsular Malaysia, expanding long-term monitoring from the Neotropics to Southeast Asia. Establishing a large plot in a lowland dipterocarp forest helped researchers test whether patterns seen at BCI also held in Asian rainforests. The Pasoh site became a long-running reference point for regional biodiversity and forest change studies.
After plot setup at Pasoh, the first full census was completed, creating a baseline map of tree locations, species identities, and sizes. This baseline is essential because later censuses can then measure real change—growth, deaths, and new recruits—rather than just a single snapshot. The repeat-census design is what turns a plot into a long-term monitoring program.
Pasoh is listed as joining the ForestGEO network in 1990, reflecting a shift from individual plots toward a coordinated multi-site system. Network membership supports consistent field standards and makes cross-site comparisons more reliable. This coordination later became especially important for understanding regional differences between Amazonian and Southeast Asian forests.
Researchers established the Lambir Hills Forest Dynamics Plot in Sarawak, Malaysia, adding a very species-rich Bornean rainforest to long-term monitoring. Having multiple large plots within Southeast Asia made it possible to compare how different dipterocarp forests behave through time. Lambir also helped extend the network’s reach into the island rainforests of the region.
The Bukit Timah Forest Dynamics Plot was initiated in Singapore’s Bukit Timah Nature Reserve, a small but important remnant of primary forest. Unlike many large, remote plots, this site offered a way to study long-term forest dynamics under strong isolation and fragmentation pressures. The first census began soon after initiation, establishing a repeatable record of change in a highly urbanized landscape.
A 25-hectare Forest Dynamics Plot was established in the Sinharaja World Heritage Site, the largest remaining area of Sri Lanka’s rain forest. Adding Sinharaja broadened long-term monitoring across tropical Asia beyond Malaysia and Singapore. It also supported research focused on high endemism (many species found nowhere else) and how those forests change over time.
CTFS–ForestGEO helped establish a major forest dynamics plot in Yasuní National Park, Ecuador, expanding standardized plot monitoring into a globally important Amazonian biodiversity region. This strengthened the network’s ability to compare tropical forests across continents using the same census approach. For the Amazon, Yasuní became one of the flagship long-term sites for tracking biodiversity and forest change.
ForestGEO describes itself as the global network that grew out of earlier tropical plot efforts (CTFS), supporting coordinated long-term monitoring across many sites. The network emphasizes consistent tree-census protocols and shared data resources to study biodiversity, forest function, and environmental change. This formal framing helped connect Amazon and Southeast Asia sites into one comparable research system.
By 2023, Pasoh had conducted repeated censuses at roughly five-year intervals and began work toward an eighth cycle, showing the endurance of the monitoring program. Ongoing censuses are central to detecting slow trends (like long-term shifts in mortality) as well as responses to events (like storms) across decades. The update also illustrates how disruptions such as the COVID-19 pandemic can delay field campaigns without ending long-term monitoring.
The Sinharaja plot completed its sixth census in 2025 after fieldwork running from early 2024 to May 2025. Completing another full census demonstrates that the site is still actively maintained, despite field challenges such as heavy rainfall and wildlife hazards. Continued censuses keep the plot useful for long-term biodiversity monitoring and for comparing trends across Asian and Amazonian ForestGEO sites.
ForestGEO Tropical Plot Network: Amazon and Southeast Asia Sites (1990s–present)