TRI Field Site: Yasuni National Park

Yasuni National Park and the adjacent Hauorani Ethnic Reserve cover c.1.6 million hectares of lowland rain forest in Amazonian Ecuador. Yasuní has global conservation significance: it has extraordinary levels of biodiversity, as well as the potential to sustain this biodiversity into the future. These two important factors are largely because of its 1) large size and little human development,  2) intact large-vertebrate assemblage, 3) IUCN level-II protection status, which is unique in the region, and 4) to-date, Amazonian-wide droughts have not impacted the area and it seems likely to maintain wet, rain forest conditions into the future.

TRI supports focal projects in the Park, building on the long-term research by the TRI Director, collaborators, and other researchers. Several overlapping interests intersect within and around the Park, including: amazing levels of biodiversity and value for ecology, conservation, and ecosystem services; ecotourism and the opportunity to experience Amazonian wilderness and indigenous cultures; indigenous, local, and national community interests in terms of development, culture, and education; exploration and exploitation of oil reserves; illegal logging and wildlife extraction. Students can investigate a wide variety of complex ecological, socio-economic, and cultural questions.

Diversity and dynamics of tropical tree species

Within YNP, a 50-ha permanent forest dynamics plot is censused every 5 years, to document tree recruitment, growth, and survival. This makes it very easy to monitor populations of focal species, such as the 16 species in the Myristicaceae, the six species of Cecropia, and many 'devil's gardens' dominated by Duroia hirsuta. Projects could build on these long-term data sets on individual tree reproduction and growth, or focus on other interesting species. For example, comparing male and female trees of dioecious taxa offers insights into the trade-offs in resource allocation patterns.

Distribution and dynamics of understory herbaceous rain forest plants

Compared to the trees that define the forest, knowledge of herbaceous plants is extremely lacking. We have been monitoring large herbaceous plants such as Heliconia, Costus, Renealmia, Besleria, throughout the plot for several years at 5-m spatial scales. More detailed projects could follow individual plants, examine population structure, growth, phenology, dispersal, and pollination. These small plants with fairly rapid life cycles and short life spans may offer signals of long-term variation in forest dynamics.

Phenology of tropical forest trees

Nested within the tree plot is a network of seed and seedling monitoring stations where we have recorded community level reproductive phenology for 20 years. Projects could analyse subsets of this data, carry out more focused studies of select species, examine seedling growth and survival as a function of various variables. What factors will determine the phenology of tropical forests is fundamental as climates change.

Herbivory and other plant–animal interactions

Many tropical plants have strong (negative or positive) interactions with other plants and animals. Insects and other herbivorous animals eat the soft, young leaves. Mutualist ants reside within domatia and consume sugars from extra-floral nectaries growing from the leaves they defend. Understanding the drivers of herbivory is a key question in ecology.


Support for research in Yasuni is also possible under TRI's NSF International Research Experience for Students program “Tropical Research Experience in Ecological Science (TREES)”.

Past Research Fellows: 

2023: Sophie Dauerman, Jasmine Gormley.

2022: Emma Grover, Leah Genth.

2019: Jesse Gehrke, Jasmine Liu.

2015: ELizabeth Tokarz.