Long‐term proliferation of large annual thistles in dry Mediterranean rangelands

Abstract Spiny plants comprise a large, ecologically and economically important functional group in Mediterranean rangelands. The increasing abundance of large annual thistles in grazed grasslands entails major consequences for ecosystem services. This study aims to quantify the contribution of large annual spiny plants to rangeland vegetation cover and productivity and to identify management‐ and climate‐related drivers of spiny plant distribution and performance. Using a 15‐year dataset from an extensive herbaceous pasture experiment in northeastern Galilee, Israel, we examined the effects of livestock management and climate on the cover and biomass of two dominant annual thistle species, Scolymus maculatus and Carthamus glaucus. These thistles constitute a significant proportion of pasture productivity, contributing more than 50% and 25% under high and moderate stocking density, respectively. Despite the similarity in life‐form and life‐history characteristics, each demonstrates a distinct response to both management intensity and annual climatic parameters. High stocking density had a positive effect on both cover and biomass of S. maculatus. Conversely, C. glaucus biomass estimates were higher under moderate stocking density. Distance from feeding site had significant contrasting effects on each of the focal thistles. Relative humidity and temperature were the most sensitive climatic parameters in explaining the variation in cover and biomass of the two thistles. The directionality of the two species' responses suggests that S. maculatus attains higher biomass than C. glaucus under dry and warm conditions. The proliferation of both large thistles under variable stocking densities and climatic conditions increases productivity but reduces the palatable vegetation of Mediterranean rangelands by 27%–50%

Appendix D. Patterning of factor relationships with litter decomposability fitted within individual sites in relation to the range of factor variation and sample size at the study sites.

Patterning of factor relationships with litter decomposability fitted within individual sites in relation to the range of factor variation and sample size at the study sites

Appendix A. List of selected treatments at each site.

List of selected treatments at each site

Appendix B. Near-infrared reflectance spectroscopy calibrations between initial litter spectral properties and (a) litter decomposability and (b) litter quality.

Near-infrared reflectance spectroscopy calibrations between initial litter spectral properties and (a) litter decomposability and (b) litter quality

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity