Cycle 4 (2015 Deadline)
Functional diversity of interrelated photosynthesis and water use of Central Amazonian trees
PI: Tomas Domingues (email@example.com), 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
|Two Master’s students from INPA´s Post Graduation Program on Tropical Forest Sciences carry out field work in the Amazon: Julyane Pires (left) and Ana Gracy Ribeiro (right). Photo courtesy of Dr. Domingues.|
The top achievement on this project during the first quarter of 2020 was the successful completion of the internship of PhD student Maquelle Neves with Dr. Jia Hu at the Laboratory of Tree Ring Research at the School of Natural Resources and the Environment, University of Arizona. Although the internship was cut short by a couple of weeks due to the COVID-19 pandemic, Maquelle acquired substantial experience in wood anatomy and tree ring and carbon stable isotope analyses. Thanks to her visit, she has established an ongoing research partnership with her host Dr. Hu. The establishment of such cooperation networks is an essential step for Maquelle to establish herself as an independent researcher. She will spend the next academic semester in Ribeirão Preto, participating as a teaching assistant in Dr. Domingues’s undergraduate course on Ecosystem Ecology and writing her thesis. A set of short video clips highlighting some of Maquelle's work in Dr. Hu's lab is available at https://www.youtube.com/watch?v=4e80g9WCNX0&list=PLoaZcQCdfs8uYdsAt6KcdwAwOP7uSHD4X.
Although fieldwork during this period has come to a halt due to the public health situation, the PI Dr. Domingues is planning two activities including his team members and researchers from other associated projects in the Manaus region. One is a two-day virtual workshop planned for the first week in June, during which students will present their recent analyses. The other is an intensive field campaign planned for October 2020, where he and his group will quantify photosynthesis and hydraulic properties of a large set of species at the AFEX (Amazon Fertilization Experiment) sites. This effort will expand understanding regarding the role of physiological acclimation of trees in response to nutrient additions. Besides planning these activities, Dr. Domingues has focused in recent months on manuscript production, submitting papers to six different journals. He has also submitted an abstract for the next annual meeting of the Ecological Society of America, which will be held during the first week of August either in person in Salt Lake City or online. Finally, in cooperation with Dr. Brian Sedio (University of Texas), Dr. Domingues has submitted a large grant proposal for the NSF/FAPESP call on “Dimensions of Biodiversity,” focusing on how plant-insect interactions shape plant evolution in the tropics.
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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