Abstract
Increasing water deficits and severe droughts are expected to alter the dynamics of vegetation post-disturbance recovery by decreasing new recruitment and limiting growth in semi-arid Mediterranean ecosystems in future. However, which vegetation metrics will be shifted and how they respond over time are not clear, and the experimental evidence is still limited. Here we assessed the impacts of a long-term (20 years) experimental drought (−30% rainfall) on the pathways of vegetation metrics related to species richness, community composition and abundance dynamics for an early-successional Mediterranean shrubland. The results indicate that the pathways of vegetation metrics were differently affected by experimental drought. The abundance of Globularia alypum follows pathway 1 (altered mature state). Simpson diversity and abundance of Erica multiflora follow pathway 2 (delayed succession) while species richness, community abundance and shrub abundance follow pathway 3 (alternative stable state). There were no significances for the resilience to extremely dry years (the ratio between the performance after and before severe events) between control and drought treatment for all vegetation metric. But, their resilience for the metrics (except Simpson diversity) to extremely dry years in 2016–17 were significantly lower than that of 2001 and of 2006–07, possibly caused by the severe water deficits in 2016–17 at mature successional stage. Principal component analysis (PCA) shows that the first two principal components explained 72.3 % of the variance in vegetation metrics. The first axis was mainly related to the changes in community abundance, shrub abundance and species richness while the second axis was related to Simpson diversity and abundance of G. alypum and E. multiflora. Principal component scores along PC1 between control and drought treatment were significantly decreased by long-term experimental drought, but the scores along PC2 were not affected. Further research should focus on successional pathways in more water-deficit conditions in Mediterranean ecosystems and the consequences of changes in vegetation recovery pathways on ecosystem functions such as biomass accumulation and soil properties.
Original language | English |
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Article number | 119970 |
Number of pages | 10 |
Journal | Forest Ecology and Management |
Volume | 506 |
Early online date | 24 Dec 2021 |
DOIs | |
Publication status | Published - 15 Feb 2022 |
Bibliographical note
Funding Information:We greatly thank all the people who maintained the field climate experiments and conducted the samplings. Funding for this research was provided by the Spanish government project PID2019-110521GB-I00, Catalan government project SGR2017-1005, Academy of Finland (340744, SensBVOCs), Fundación Ramón Areces grant ELEMENTAL-CLIMATE, the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 758873, TreeMort), and the FWF Austria science Fund (Lise Meitner Programme M2714-B29). D.L. and C.Z. developed the ideas and analysed the data; J.P. and R.O. conceived the ideas and collected the data; D.L and C.Z wrote the manuscript with contributions from all co-authors. All data and code are available upon request to CZ ([email protected]).
Publisher Copyright:
© 2021
Keywords
- Abundance dynamics
- Climate change
- Community composition
- Long-term drought experiment
- Mediterranean shrublands
- Species diversity
- Succession pathways
- Vegetation metric space
ASJC Scopus subject areas
- Forestry
- Nature and Landscape Conservation
- Management, Monitoring, Policy and Law