Marielos Peña-Claros is a tropical forest ecologist. In her research she addresses fundamental research questions that have applied relevance because she is interested in science that has an impact on the ground and that is relevant for policy and decision making. Over the past 24 years her research has mainly focused on the ecology and management of forests used for the harvesting of timber and non-timber forest products, and on forests undergoing forest succession after shifting cultivation. Recently, she is working on the effects of past-human activities on forest composition and dynamics. This is a fascinating topic that is changing how we view and understand the ‘pristine’ forests. 

Marielos is particularly interested in the impact of forest management on biodiversity, forest dynamics, ecosystem services, and forest recovery. With her research she aims to provide ecological information needed for defining better management practices that maintain biodiversity while enhancing productivity and that allow for sustainable use. She uses a wide variety of tools (field observations, large scale experiments, functional approach) for her research, and participates in several interdisciplinary research efforts. Her work takes place in the Neotropics.

She is the President of the Association of Tropical Biology and Conservation.