Climate change will decrease precipitation and increase rainfall variability in Eastern Mediterranean regions, with responses of plant communities largely uncertain. Here, we tested short-term responses of dryland plant communities to contrasting rainfall regimes using reciprocal transplants of soil and seed banks. We exposed three annual plant communities to very different climatic conditions along a steep rainfall gradient. We tested for the role of climate vs. community origin on community response and resistance. In parallel, we asked whether origin-specific climatic adaptations predict compositional shifts across climates. Due to an extreme drought, all plants in the driest climate failed to reach maturity. For the remaining two community origins, the most dry-adapted species in each community increased in dry climate and the wet-adapted species increased in wet climate. Dry community origins showed large compositional shifts while maintaining stable plant density, biomass and species richness across climates. Conversely, wet communities showed smaller compositional shifts, but larger variation in biomass and richness. This asynchrony in species abundances in response to rainfall variability could maintain structural community stability. This, in combination with seed dormancy, has the ability to delay extinction in response to climate change. However, increasing occurrence of extreme droughts may, in the long-term, lead to loss of wet-adapted species.
species_abundance
species_abundance.csv: contains information of species found at each plots
• The first column assigns a number to each plot.
• Each row corresponds to a plot.
• Each column represents a species,
• Numbers in each cell represent number of individuals of a species found in a plot: e.g. the cell located at the intersection between row x and column j reports the number individuals belonging to the species j counted in the plot x
the file contains 79 rows instead of 80, because one plot was destroyed by a mole
plot_density_richness
plot_density_richness.csv: contains data of species richness and density of individuals per each plot.
Variables:
• site: provides information on the whether the plots are located at at Mediterranean (M) or the semi-arid (SA) site
• soil_origin: provides information on the origin of the soil, Mediterranean (M) or semi-arid (SA).
• block: identifying the block where a plot is situate (1-10)
• plot: identifying the plot that was recorded (1-4)
• SpRi: species richness, i.e. number of species counted in each plot
• TotDens: total number of individuals counted in each plot
the file contains 79 rows instead of 80, because one plot was destroyed by a mole these data were also used for the modeling of species richness and total density of individuals per sites and soil origins
species_CNG
species_CNG.csv: contains data on mean rainfall niche and Climatic Niche Group for each species recorded
Variables:
Species: species name
rainfall: mean rainfall niche
CNG: climatic rainfall niche group ranging from 1 to 4
community_diversity
community_diversity.csv: Used for models of species diversity across sites and soil origins
Variables:
• site: provides information on the whether the plots are located at at Mediterranean (M) or the semi-arid (SA) site
• soil: provides information on the origin of the soil, Mediterranean (M) or semi-arid (SA).
• treatment: combination of soil and site information
• block: number of block when plots were located (1-10)
• plots: identifier of plot number and soil origin (1-4)
• ShannonWiener: Shannon Wiener index associated to each plot
the file contains 79 rows instead of 80, because one plot was destroyed by a mole
biomass_community_data
biomass_community_data.csv: dry weight of total biomass for each plot
Variables:
• site: provides information on the whether the plots are located at at Mediterranean (M) or the semi-arid (SA) site,
• soil: provides information on the origin of the soil, Mediterranean (M) or semi-arid (SA),
• block: number of block where plants are located (1-10)
• plot: identifier of plot (1-4)
• total.biomass: dry weight in grams of total community aboveground biomass
the file contains 79 rows instead of 80, because one plot was destroyed by a mole
Arid_Communities
Arid_communities.csv: data set used for graphs in Appendix 1 on communities emerging from arid soil origins.
Variables:
• Climate: provides information on the whether the plots are located at at Mediterranean (M) or the semi-arid (SA) or arid (A) site,
• Block: identifies the number of the block where plots are found
• plot: identifies the plot
• Soil: provides information on the origin of the soil, Mediterranean (M), semi-arid (SA) or arid (A)
• Richness: total number of species in each plot
• TotalDensity: Total number of individuals in each plot
• ShannonWiener: Shannon-Wiener index calculated per each plot