The Science
Studies and raw data on root systems in Puerto Rican tropical forests, including data from Spanish-language publications not previously published in English, were synthesized and analyzed in comparison with other tropical studies, and gaps were exposed for future studies.
The Impact
Studies including root data in Puerto Rico are representative for the tropics. However, fine-root functional trait data for tropical ecosystems have not been fully explored. Our synthesis will be used to enrich root database representation for the tropics, and ultimately better inform Earth System Models.
Summary
Fine roots play an important role in plant nutrition, as well as in carbon, water and nutrient cycling. Fine roots account for a third of terrestrial net primary production (NPP), and inclusion of their structure and function in global carbon models should improve predictions of ecosystem responses to climate change. Unfortunately, studies focusing on underground plant components are much less frequent than those on aboveground structure. This disparity is more marked in the tropics, where one third of the planet’s terrestrial NPP is produced. Available tropical forest fine root data in Puerto Rico is overrepresented considering its land cover. This Caribbean island’s biodiversity, frequency of natural disturbances, ease of access to forests, and long-term plots have created an ideal place for the study of tropical ecological processes. This literature review emphasizes 50 years of root research and patterns revealed around Puerto Rico. The data in this review were compiled from scientific publications, conference reports, symposiums, and include new raw data shared by some researches. Emergent patterns for fine roots include the shallower distribution of fine roots compared to other tropical forests, the greater root:shoot ratio compared to other tropical metanalysis, the little variation in root phosphorus concentrations among forest types, and the slow recovery of root biomass after hurricane disturbance. Because more than half of the data on roots come from the wet tropical Luquillo Experimental Forest, other habitat types are under-represented. Gaps in knowledge about fine roots in Puerto Rico’s ecosystems are noted as examples to promote and guide future studies.
Contacts (BER PM): Daniel Stover, SC-23.1, Daniel.Stover@science.doe.gov (301-903-0289)
PI Contact: Richard Norby, Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, rjn@ornl.gov, 865-576-5261
Funding
This research was supported as part of the Next Generation Ecosystem Experiments‐Tropics, funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research. Oak Ridge National Laboratory (ORNL) is managed by University of Tennessee (UT)-Battelle, LLC, for the U.S. Department of Energy under contractDE-AC05-00OR22725.
Publications
Yaffar D and Norby RJ. 2020. A historical and comparative review of 50 years of root data collection in Puerto Rico. Biotropica, DOI: 10.1111/btp.12771