Cycle 4 (2015 Deadline)
Functional diversity of interrelated photosynthesis and water use of Central Amazonian trees
PI: Tomas Domingues (firstname.lastname@example.org), University of São Paulo
U.S. Partner: Pierre Gentine, Columbia University
Project Dates: November 2015 - October 2020
Team member Maquelle Garcia takes measurements at the top of the tree canopy (photo courtesy of Dr. Domingues).
This project will generate novel understanding on the diversity of plant traits related to water use and photosynthesis. The functional diversity present in a given community is a key dimension of biodiversity that effectively modulates how forests respond to disturbances, such as logging, precipitation, and temperature extremes or the increase in carbon dioxide concentration. It also determines the extent of the feedback between forest and climate, therefore informing us on possible consequences of forest mortality or land use change. To better predict the resilience of the forest and its capacity to provide ecosystem services, it is essential to evaluate the current spectrum of functional diversity, still a major unknown component in biodiversity research. Dr. Domingues and his colleagues will use a new approach looking at the carbon and water cycles as fundamentally coupled at both the leaf and tree level. In order to achieve a qualitative and quantitative assessment of water and carbon strategies by Amazonian trees, they will continuously monitor both the transport of water in tree trunks and the continuous expansion and contraction of the tree’s bole diameter, which relates to water storage, mobilization of photosynthetic products, and growth. This will be complemented by leaf-level measurements of photosynthetic apparatus and hydraulics to comprehend the individual link of photosynthesis with water usage. This novel dataset will demonstrate the coupling between transport of water and carbon within trees and how it relates to forest productivity. The new data will be applied to broader scales by using land-surface and ecosystem models to simulate the interaction between forest and atmosphere at different scenarios of functional diversity. This step will be achieved by collaboration with U.S. Government-supported partner Pierre Gentine, who is implementing a soil-plant-atmosphere-continuum model able to reproduce the carbon and water relationship in the Community Land Model. Brazilian students will also receive much-needed training in computational modeling.
The proposed research will shed light on the role of biodiversity not only in maintaining and improving quality of life for inhabitants of the Amazon region but also for improving water security in other areas. By characterizing current variability in water and carbon use strategies expressed by Amazonian trees, it is possible to assess how much biodiversity loss within this group is tolerable, without seriously compromising ecosystem functioning. The information to be generated by this project will help in evaluating ecosystem integrity in areas where disturbance has already occurred. For example, it will be possible to assess disparities between pristine forest and secondary vegetation, in terms of ecosystem response to water stress whether from bottom up (soil to leaves induced by dry soil conditions) or top down (from leaves to soil induced by dry or hot weather conditions), according to species composition of the community. As a result, plant communities can be evaluated in terms of resilience to further climatic extremes. The products of this research will also aid in guiding species selection for vegetation restoration efforts. For example, such information will be of great value to local community initiatives focusing on production of tree saplings for reforestation programs or ecosystem improvement actions.
Summary of Recent Activities
From July 30 through August 3, 2019, Dr. Tomas Domingues and his PhD student Maquelle Garcia attended the 56th Annual Association for Tropical Biology and Conservation (ATBC) meeting in Antananarivo, Madagascar. During this conference, besides presenting eight posters and talks, they and other colleagues also organized a thematic symposium entitled “Large-scale ecosystem manipulation experiments as a way forward to tropical vegetation ecology,” during which participants shared their views on how to advance research in the Amazon through experimentation. Dr. Domingues notes that the research community clearly recognizes the difficulties of performing large experiments in that region, but also all, without exceptions, are aware of the strong commitment of local students, researchers, and helpers to protecting the area. The conference provided a venue for discussions on how to transfer knowledge generated by this PEER project to a broader, non-scientist audience, but this is still in its early stage.
In early October 2019, Maquelle Garcia began a six-month exchange visit to the University of Arizona, where she is currently working with Prof. Jia Hu to advance her analyses of leaf and wood anatomy. Her work in Arizona will generate important data for her PhD thesis that will also allow the PEER team to link water use to anatomical characteristics of different species.
The PI also reports that a manuscript he co-authored with PEER team members Katrin Fleischer, Sabrina Garcia, Adriana Grandis, and Carlos Quesada has been published by Nature GeoSciences. A link to the paper is included below, along with links to other recent publications (three of which appeared during the third quarter of 2019).
Beyond the research aspects of the project, Dr. Domingues has continued working to put his research into action through interactions with relevant government organizations. He serves as a council member for two State-managed conservation units (Estação Ecologica de Ribeirão Preto and Parque Estadual do Vassununga). Those two councils are headed by members of the Brazilian Forestry Institute and are composed of representatives of various sectors of society (the private sector, universities, NGOs, and environmental state and municipal agencies). The bodies are working on ways to establish protocols for fauna and flora monitoring that can be sustained continuously. The focus is on the involvement of park managers, the private sector, and university-based researchers in both the planning and implementation phases. Researchers will propose a set of standardized protocols for continuous monitoring of populations of key animal groups (butterflies, bees, birds, mammals, amphibians), plant diversity and dynamics (growth, recruitment, and mortality), and key ecological processes (primary productivity and carbon and nitrogen cycle). With the protocols, the individual conservation units will hire private companies to implement the protocols and collect data. The data, after being analyzed and summarized by researchers, will be shared with the park managers in order to support decision making. The greatest challenge is ensuring steady funding, and one possibility is to access the São Paulo State Environmental Compensation Fund, which draws its resources from fines and settlements derived from enforcement of environmental laws.
Dr. Domingues notes that there is clearly a strong demand for research products that can be shared more readily with the community, and Brazil is no exception. Doing this can be difficult for scientists, as it requires them to take actions for which they often have very little training. That said, besides working to complete their data gathering and analysis tasks on the PEER project, the PI and his team intend to focus during this last year of the project on actions such as the production of pamphlets and other informational materials to explain how biodiversity is important to the health of the Amazon forest. In particular, they will focus on how tree species vary widely in how much water they use, how productive their photosynthesis can be, and how vulnerable they are to extreme droughts and global change.
Following are links to several other papers and a book reported by the PI as being based on his and his team's PEER-supported work:
- Smith, N.G., Keenan, T.F., Prentice, I.C., et al. (2019) Global photosynthetic capacity is optimized to the environment. Ecology Letters 22(3):506-517. DOI: 10.1111/ele.13210.
- Pereira, I.S., et al. (2019). Performance of laser-based electronic devices for structural analysis of Amazonian terra-firme forests. Remote Sensing 11:510.
- Grossman, D., and D.M. Lapola. (2018). Floresta em riesgo: as mundanças climáticas destruirão a Floresta Amazônica? (PDF download)
- Domingues, T.F., Ometto, J.P.H.B., Nepstad, D.C. et al. (2018) Ecophysiological plasticity of Amazonian trees to long-term drought Oecologia 187: 933
- Butler EE, Datta A, Flores-Moreno H, et al. (2017) Mapping local and global variability in plant trait distributions. Proceedings of the National Academy of Sciences
- Bahar NHA, Ishida FY, et al. (2017) Leaf‐level photosynthetic capacity in lowland Amazonian and high‐elevation Andean tropical moist forests of Peru. New Phytologist
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