In this Special Issue of Science, five Reviews highlight new insights into the impacts of drought on social, ecological and agricultural systems worldwide. Political fragmentation in how community water systems are managed in the United States contributes to disparities in water security in American communities and households, says Megan Mullin in one Review. Even though, by global standards, most Americans have reliable access to safe drinking water, access to clean water is still unequal within the country, particularly in the nation's rural and impoverished communities. This inequality is made worse by the ever-growing risk of drought, says Mullin; increasing drought can push most communities to the brink of their water supplies. Identifying and addressing weaknesses in water management policy is a crucial step towards ensuring water security for all Americans, Mullin says. Toby Ault highlights the various definitions and physical causes of drought and the analytical tools that enable us to evaluate and predict drought risks in another Review. In a third, Timothy Brodribb and colleagues discuss the vulnerability of Earth's forests as many regions become hotter and drier; according to Brodribb et al., many long-lived tree species may be particularly susceptible to damage via water stress. Aditi Gupta and colleagues discuss our current understanding of how plants alter their physiology to adapt to water insufficiency - research that is informing the development of high-yield, drought-resistant crops. In a final Review, Franciska De Vries and colleagues discuss the growing body of research highlighting the importance of soil microbiota in endowing plants with resilience to environmental stressors; understanding how crop plant microbiota responses buffer drought may enable sustainable food production on a drier planet.
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Science