Drought decreases water storage capacity of two arboreal epiphytes with differing ecohydrological traits.

Autor: Moore AFP; Skidaway Institute of Oceanography, University of Georgia, 10 Ocean Science Circle, Savannah, GA 31411, United States of America. Electronic address: althea.moore.phd@gmail.com., Antoine J; Franklin and Marshal College, Department of Biology, 415 Harrisburg Ave., Lancaster, PA 17603, United States of America., Bedoya LI; Franklin and Marshal College, Department of Biology, 415 Harrisburg Ave., Lancaster, PA 17603, United States of America., Medina A; Franklin and Marshal College, Department of Biology, 415 Harrisburg Ave., Lancaster, PA 17603, United States of America., Buck CS; Skidaway Institute of Oceanography, University of Georgia, 10 Ocean Science Circle, Savannah, GA 31411, United States of America., Van Stan JT; Cleveland State University, Department of Biological, Geological and Environmental Sciences, 2121 Euclid Ave, Cleveland, OH 44115, United States of America., Gotsch SG; Franklin and Marshal College, Department of Biology, 415 Harrisburg Ave., Lancaster, PA 17603, United States of America; University of Kentucky, Department of Forestry and Natural Resources, 105 T.P. Cooper Building, 730 Rose Street, Lexington, KY 40546-0073, United States of America.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2023 Oct 10; Vol. 894, pp. 164791. Date of Electronic Publication: 2023 Jun 10.
DOI: 10.1016/j.scitotenv.2023.164791
Abstrakt: Arboreal epiphytes, plants that grow on trees, can significantly increase rainwater storage and evaporation (i.e., "interception") within canopies. Drought conditions may affect this hydrological role, as epiphytes' physiological responses change leaf properties that affect water retention. Drought-induced changes in epiphyte water storage capacity could substantially alter canopy hydrology, but have not been studied. We tested the effects of drought on the water storage capacity (S max ) of leaves and leaf properties of two epiphytes with distinct ecohydrological traits: resurrection fern (Pleopeltis polypodioides), and Spanish moss (Tillandsia usneoides). Both species are common in maritime forests of the Southeastern USA, where climate change is expected to decrease precipitation in spring and summer. To simulate drought, we dried leaves to 75 %, 50 %, and ~25 % of fresh weight, and quantified their S max in fog chambers. We measured relevant leaf properties: hydrophobicity, minimum leaf conductance (g min ; a measure of water loss under drought), and Normalized Difference Vegetative Index (NDVI). We found that drought significantly reduced S max and increased leaf hydrophobicity for both species, indicating that lower S max may be due to shedding of droplets. While the overall reduction in S max did not differ between the two species, they exhibited distinct drought responses. Dehydrated T. usneoides leaves had lower g min , demonstrating the ability to limit water loss under drought. P. polypodioides increased g min when dehydrated, consistent with its extraordinary ability to withstand water loss. NDVI decreased with dehydration in T. usneoides but not P. polypodioides. Our results suggest that increased drought may have a dramatic effect on canopy water cycling by reducing the S max of epiphytes. Reduced rainfall interception and storage in forest canopies could have widespread effects on hydrological cycling, thus understanding the potential feedbacks of plant drought response on hydrology is crucial. This study highlights the importance of connecting foliar-scale plant response with broader hydrological processes.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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