The National Science Foundation (NSF) has awarded grants to three Arnold Arboretum scientists to advance two new botanical initiatives. Senior Research Scientist Campbell Webb and Sargent Fellow Sarah Mathews received NSF funding to inventory and assess the plant diversity of the species-rich Indonesian archipelago. NSF will also fund investigations by Sargent Fellow Maciej Zwieniecki and the University of Chicago’s Kevin Boyce to study leaf fossils and living plants to enhance our understanding of evolutionary linkages between leaf structure and plant physiology.
The award granted to Webb and Mathews will fund studies to record the biographic and ecological diversification of trees in Indonesia, and also support efforts for local management of this diversity. Due to a complex geological and environmental history, Indonesia contains forests with some of the richest plant diversity on Earth. Timber harvesting and oil palm expansion have drastically reduced the area of lowland forests, threatening this diversity before it has been studied and thoroughly understood. This project will pioneer new methods for recording tree species composition and environmental variables on five islands (Borneo, Sulawesi, New Guinea, Seram, Sumbawa). The data will enable Webb and Mathews to investigate the historical processes by which the forests were assembled, opening opportunities for a greater understanding of how forests will respond to future environmental changes.
Although foreign institutions currently manage most of Indonesian biodiversity, there is a need for megadiversity nations like Indonesia to lead the collection, digitization, and networking of their own biodiversity information. This project will develop capacity and leadership in biodiversity informatics in Indonesia, as well as in the United States, via joint field expeditions, meetings, short courses, and sustained interactions with local software developers. The informatics resources themselves will aid foresters and conservationists to better know and manage these forests.
The project by Zwieniecki and Boyce funded by NSF will employ leaf fossils and living plants to gain a better understanding of the functional link between plant habit and ecophysiology, and to reconstruct the nature of prehistoric forests. Detached leaves are among the most common plant fossils, but the absence of their stems makes it difficult if not impossible to learn about the forests where they lived. However, as records of the primary interface between plants and their environment, fossilized leaves offer a valuable source of information regarding past climates and atmospheric compositions. In addition, the plant to which leaf is attached is as much a part of leaf’s environment as the surrounding climate. From this perspective, fossils of leaves may also preserve an untapped wealth of information concerning the habit and ecology of the parent plant as well as the overall structure of vegetation in the landscape.
Using the emerging mechanistic understanding of how leaf structure and physiology are linked, Zwieniecki and Boyce will study three aspects of whole-plant ecophysiology with leaf fossils: plant habit (whether it grows as a low shrub or tall tree); adaptation to water vapor pressure deficit (a sunny, exposed environment or a shaded, understory environment); and carbon assimilation and transpiration capacities. Studies will employ a diverse series of field-based measurements in both tropical and temperate forests, as well as greenhouse and growth chamber experiments to simulate conditions that no longer exist in the modern world. Tools advanced by the project will enhance understanding of the evolution of physiology and ecology, and provide a new approach for reconstructing prehistoric climates and carbon and hydrological cycles.