Grassy Trees: Transitional Solutions in a Transitioning World

Cover Illustration: Maryam Lootah for Washington Square News

Our recent paper in Trends in Ecology and Evolution highlights a group of plants that has long occupied a blind spot in forest ecology. Large enough to reach the canopy like trees, yet fast-growing and anatomically more similar to grasses, bamboos, bananas, palms, and many other giant monocots are true functional hybrids. We refer to them collectively as grassy trees.

Their close association with agriculture and human-managed landscapes often leads them to be viewed as crops rather than forest species. Yet many grassy trees are dominant components of tropical forests and play major ecological roles. Evolutionarily, they are monocots without secondary growth and therefore closer to grasses than to woody trees. At the same time, their large stature and long-lived presence in forest canopies make them difficult to reconcile with conventional notions of what a grass should be.

This awkward position between familiar categories has contributed to their marginalization in both ecological research and conservation discourse. Dichotomous thinking tends to force grassy trees into one of two boxes. When treated as trees, their fundamentally different anatomy and growth strategies are overlooked. When treated as grasses, their ecological importance in forests is obscured. Neither perspective adequately captures what they are.

The same binary thinking shapes how grassy trees are viewed in conservation. They are often cast either as villains or as heroes. On one hand, plantations of oil palms and bananas are frequently associated with deforestation and biodiversity loss. On the other hand, many grassy trees function as keystone species in tropical landscapes, providing habitat, food resources, carbon storage, and ecosystem services at large scales. Rather than fitting neatly into either category, grassy trees often occupy the ecological and social spaces between natural forests and human land use.

Recognizing grassy trees as a distinct functional group is therefore not merely a matter of classification. It offers a more accurate framework for understanding how forests work, how people interact with them, and how tropical landscapes may be managed in a rapidly changing world.

Our paper is only a first step toward a more holistic understanding of grassy trees, a group of species that is particularly important across the tropical world, where biodiversity conservation, human livelihoods, and environmental change are deeply intertwined. By proposing a functional perspective that evaluates both the benefits and trade-offs of grassy trees as nature-based solutions, we hope to move beyond simplistic narratives that portray them as either ecological villains or heroes.

More broadly, we call for greater attention to growth forms that fall outside conventional categories and for a more inclusive view of forests as social–ecological systems. Looking beyond trees ultimately means looking beyond simplified representations of nature itself, toward landscapes where ecological processes and human activities are inseparably connected.

Selected Media Coverage:
NYU News by James Devitt
Washington Square News by Zachary Karp
The Earth and I