In the heart of Khao Yai National Park, a 30-hectare plot of land is mapped with such precision that it is helping scientists worldwide understand the future of our tropical forests.
Nestled in the core of Thailand's first national park, a living laboratory breathes quietly. Here, every single tree, shrub, and woody climber is known, measured, and tracked over time. This is the Mo Singto Forest Dynamics Plot, a cornerstone of ecological research where scientists are unraveling the complex web of life that sustains one of the planet's most vital ecosystems. Part of a global network coordinated by the Smithsonian Tropical Research Institute, Mo Singto provides invaluable data that helps us understand how forests grow, change, and respond to environmental pressures 1 . For decades, researchers have patiently collected data here, piecing together the hidden conversations between plants and animals, and the subtle competition for light and space that shapes the forest's very structure.
The Mo Singto plot is situated in the broad-leaved, seasonal evergreen forest of Khao Yai National Park, at altitudes ranging from 725 to 815 meters 1 .
The area's scientific significance predates the plot itself. The Mo Singto area has been a study site for white-handed gibbons since 1979, offering a rare long-term perspective on the behavior and ecology of these charismatic apes 1 . This existing foundation of research made it an ideal location for establishing a permanent forest dynamics plot, which has since become a vital training ground for graduate students pursuing master's and doctoral degrees 1 .
One of the many fascinating studies conducted at Mo Singto investigates the intricate relationship between lianas (woody vines) and the trees that support them. Lianas are a critical component of tropical forests, and their climbing strategies are as diverse as the plants themselves. A pivotal 2017 study led by Natthida Khiewbanyang examined how the physical characteristics of host trees influence the climbing success of these lianas 5 .
The research team randomly selected 1,560 individual liana stems (called ramets) within the Mo Singto plot to serve as their subjects 5 . For each ramet, they meticulously recorded:
The study revealed that the relationship between lianas and their hosts is not random but is profoundly shaped by the liana's climbing technique.
| Climbing Strategy | Preferred Host Tree Size | Preferred Bark Texture | Probable Reason |
|---|---|---|---|
| Twiner, Hook, Tendril | Small | Slightly Rough | Easier for delicate structures to encircle or attach |
| Adventitious Root | Large | Rough | More surface area and crevices for root attachment |
| Scrambler | Independent | Slightly Rough | Relies on branching structure, not trunk diameter |
Source: 5
Understanding these relationships is more than an academic exercise. Lianas play a crucial role in forest dynamics. They can influence tree growth, reproduction, and mortality. An overabundance of lianas can suppress tree regeneration and even reduce the forest's capacity to store carbon. By decoding which trees are most vulnerable to certain liana types, scientists can better predict how the forest structure might change in response to climate disturbances like droughts, which often favor liana growth over trees.
The long-term research at Mo Singto relies on a suite of specialized tools and methods. The following table outlines the essential "research reagents" used to maintain and study this vibrant ecosystem.
| Tool / Material | Function | Application in the Field |
|---|---|---|
| Permanent Grid System | A fixed coordinate system of 20m x 20m squares laid across the 30-hectare plot | Allows for precise mapping and long-term tracking of every single woody plant, enabling scientists to revisit the exact same tree year after year to monitor growth and survival 1 |
| Diameter Tape (D-tape) | A specialized tape measure calibrated to directly read the diameter of a tree trunk | Used to measure the girth of every stem ≥1 cm in diameter at a standardized height of 1.3 meters (diameter at breast height, or DBH). This is the primary metric for tracking growth 1 |
| Field Database & Plant Identification Guides | A curated collection of known plant species and their characteristics for the plot | Critical for accurately identifying and recording the 262+ species of trees and shrubs and 120+ species of woody climbers, ensuring data consistency across different research teams 1 |
| ArcGIS Software | A powerful geographic information system (GIS) for spatial analysis and mapping | Used to create highly detailed maps of the forest, visualizing the spatial distribution of species, analyzing patterns of regeneration, and modeling ecological relationships 1 |
Mo Singto area begins as a study site for white-handed gibbons 1
Initial census of the Mo Singto Forest Dynamics Plot identifies 262 species of trees and shrubs 1
Landmark study on liana climbing strategies published by Natthida Khiewbanyang 5
Ongoing monitoring and research as part of the global Smithsonian ForestGEO network 1
The Mo Singto Forest Dynamics Plot is far more than a collection of data points. It is a window into the soul of the forest, revealing the delicate and dynamic balance that sustains tropical ecosystems. The research conducted here—from the long-term monitoring of gibbons to the detailed study of liana relationships—provides critical insights for conservation efforts not just in Khao Yai, but for tropical forests worldwide 1 7 .
Part of the Smithsonian ForestGEO network, contributing to global forest research 1
Vital training ground for graduate students pursuing advanced degrees in ecology 1
Provides baselines to measure forest responses to climate change and human impacts
As climate change and human pressure continue to alter our planet, the long-term data from Mo Singto and its sister plots across the globe become increasingly vital. They are the baselines against which we can measure change, the models that help us predict the future, and a powerful reminder of the profound complexity and beauty of the natural world we strive to protect.