Shift in community structure mainly by the losses of herbs in long-term warming and drought experiments and natural extreme droughts in an early-successional Mediterranean shrubland
Liu, Daijun (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Estiarte, Marc (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Ogaya Inurrigarro, Romà (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Yang, Xiaohong (Xi nan da xue (China). Key Laboratory of Horticulture Science for Southern Mountainous Regions)
Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)

Date:	2017
Abstract:	Global warming and recurring drought are expected to accelerate water limitation for plant communities in semiarid Mediterranean ecosystems and produce directional shifts in structure and composition that are not easily detected, and supporting evidence is scarce. We conducted a long-term (17 years) nocturnal-warming (+0. 6°C) and drought (-40% rainfall) experiments in an early-successional Mediterranean shrubland to study the changes in community structure and composition, contrasting functional groups and dominant species, and the superimposed effects of natural extreme drought. Species richness decreased in both the warming and drought treatments. Responses to the moderate warming were associated with decreases in herb abundance, and responses to the drought were associated with decreases in both herb and shrub abundances. The drought also significantly decreased community diversity and evenness. Changes in abundance differed between herbs (decreases) and shrubs (increases or no changes). Both warming and drought, especially drought, increased the relative species richness and abundance of shrubs, favoring the establishment of shrubs. Both warming and drought produced significant shifts in plant community composition. Experimental warming shifted the community composition from Erica multiflora toward Rosmarinus officinalis, and drought consistently shifted the composition toward Globularia alypum. The responses in biodiversity (e. g. , community biodiversity, changes of functional groups and compositional shifts) were also strongly correlated with atmospheric drought (SPEI) in winter-spring and/or summer, indicating sensitivity to water limitation in this early-successional Mediterranean ecosystem, especially to natural extreme droughts. Our results suggest that the shifts in species assembles and community diversity and composition are accelerated by the long-term nocturnal-warming and drought, combined with natural severe droughts, and that the magnitude of the impacts of climate change is also correlated with the successional status of ecosystem. The results thus highlight the necessity for assessing the impacts on ecosystemic functioning and services and developing effective measures for conserving biodiversity.
Grants:	European Commission 610028 Ministerio de Ciencia e Innovación CGL2016-79835-P Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-274
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Community diversity ; Composition shifts ; Frequent droughts ; Functional groups ; Global warming ; Long-term climatic experiments ; Mediterranean ecosystems ; Species richness
Published in:	Global change biology, Vol. 23, issue 10 (Oct. 2017) , p. 4267-4279, ISSN 1365-2486

DOI: 10.1111/gcb.13763

Post-print 38 p, 1.6 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals) > Imbalance-P
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