Non-linear effects of drought under shade: reconciling physiological and ecological models in plant communities

Autor: Lorena Gómez-Aparicio, Milena Holmgren, Fernando Valladares, José L. Quero
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Stomatal conductance
abiotic stress
Light
Physiological ecology - Original research paper
Irradiance
Plant Development
Trade-off
woody seedlings
Biology
Models
Biological
semiarid woodland
Ecosystem
Biomass
Photosynthesis
Plant Physiological Phenomena
health care economics and organizations
Ecology
Evolution
Behavior and Systematics
stress-gradient hypothesis
Tropical Climate
Biomass (ecology)
oak quercus-suber
Competition
positive interactions
Ecology
Physiological condition
fungi
Water
food and beverages
Plant community
social sciences
seedling establishment
summer drought
PE&RC
Biota
Photosynthetic capacity
humanities
Droughts
Survival Rate
Plant ecology
Nonlinear Dynamics
Agronomy
Wildlife Ecology and Conservation
Plant Stomata
Interactive factors
Facilitation
biomass allocation
water relations
Zdroj: Oecologia, 169(2), 293-305
Digital.CSIC. Repositorio Institucional del CSIC
instname
Oecologia 169 (2012) 2
Oecologia
ISSN: 0029-8549
Popis: 13 pages, 5 figures, 1 table, 66 references. We thank Wageningen University for facilitating the stay of Lorena Gómez-Aparicio and José Luis Quero.
The combined effects of shade and drought on plant performance and the implications for species interactions are highly debated in plant ecology. Empirical evidence for positive and negative effects of shade on the performance of plants under dry conditions supports two contrasting theoretical models about the role of shade under dry conditions: the trade-off and the facilitation hypotheses. We performed a meta-analysis of field and greenhouse studies evaluating the effects of drought at two or more irradiance levels on nine response variables describing plant physiological condition, growth, and survival. We explored differences in plant response across plant functional types, ecosystem types and methodological approaches. The data were best fit using quadratic models indicating a humped-back shape response to drought along an irradiance gradient for survival, whole plant biomass, maximum photosynthetic capacity, stomatal conductance and maximal photochemical efficiency. Drought effects were ameliorated at intermediate irradiance, becoming more severe at higher or lower light levels. This general pattern was maintained when controlling for potential variations in the strength of the drought treatment among light levels. Our quantitative meta-analysis indicates that dense shade ameliorates drought especially among drought-intolerant and shade-tolerant species. Wet tropical species showed larger negative effects of drought with increasing irradiance than semiarid and cold temperate species. Non-linear responses to irradiance were stronger under field conditions than under controlled greenhouse conditions. Non-linear responses to drought along the irradiance gradient reconciliate opposing views in plant ecology, indicating that facilitation is more likely within certain range of environmental conditions, fading under deep shade, especially for drought-tolerant species.
This study was partly supported by the postdoctoral grant MCINN (Spain) to J.L.Q. (ref 2007-0572).
Databáze: OpenAIRE
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