Student Author(s)

Benjamin Johnson
Grace Wiesner

Faculty Mentor(s)

Dr. K. Greg Murray and Dr. Brian Yurk

Document Type


Event Date



The tropical rainforest is one of earth’s most diverse and dynamic ecosystems. Tree- or branch-falls in the forest can open gaps in the canopy, allowing light to reach the forest floor. Pioneer plants are adapted to take advantage of these conditions, sometimes emerging many years after being deposited as seeds. Light conditions change as the gap closes, impacting rates of growth and reproduction. For the past 30 years, sizes and reproductive outputs of individuals of six pioneer plant species have been measured along five transects in the Monteverde Cloud Forest Preserve at Monteverde, Costa Rica. Each 500- meter transect was chosen to be representative of different conditions in some part of the cloud forest. To model the pioneer plant demographics, we classified canopy gaps by age and size and developed a matrix population model that accounts for the differing gap environments. We also created a stochastic matrix model of gap formation and regeneration to simulate the dynamics of rainforest canopy gaps. Combined, these models will allow us to simulate pioneer plant population dynamics in the changing forest environment, and to explore how reproduction and growth rate parameters, such as seed predation rates, impact pioneer population dynamics.


This research was supported in part by a grant to Hope College from the Howard Hughes Medical Institute through the Undergraduate Science Education Program, Jacob E. Nyenhuis Student/Faculty Collaborative Summer Research Grant and the Hope College Biology and Mathematics Departments.