Biogeography of global drylands

Area of Science:

• Ecology
• Biogeography
• Environmental Science

Background:

• Drylands cover a substantial portion of the Earth's land surface and are socio-ecologically important.
• A comprehensive biogeographical synthesis of global drylands, encompassing key organisms and processes, is currently lacking.

Purpose of the Study:

• To synthesize the biogeography of global drylands, integrating information on organisms, functional traits, interactions, and ecological processes.
• To identify major research gaps and future directions for dryland biogeography.

Main Methods:

• Review and synthesis of existing literature on dryland biogeography.
• Analysis of data on vascular and nonvascular vegetation, soil microorganisms, functional traits, spatial patterns, plant-plant and plant-soil interactions, productivity, and land cover.

Main Results:

• Drylands possess a long evolutionary history and are centers for plant diversification and biodiversity hotspots.
• Plant functional diversity in drylands is substantial and influenced by traits of encroaching shrubs.
• Aridity is a key driver shaping plant interactions, spatial patterns, biocrust composition, and vegetation productivity across global drylands.

Conclusions:

• Drylands are critical ecosystems with unique biogeographical patterns driven by aridity and plant traits.
• Significant research gaps remain, including understanding vegetation spatial patterns, conducting large-scale field surveys with trait measurements, predicting interaction impacts on biodiversity, and assessing the effects of elevated CO2 on future dryland productivity.