Droughts can transform ecosystems and threaten communities, causing food shortages, decreased access to clean drinking water, wildfires, and widespread species loss. Yet droughts in the modern world look very different than historical ones. Not only are they longer and more severe as a result of climate change, but they can also have different underlying causes. In addition to hydrologic drivers of drought (e.g. a reduction in snow pack due to low winter precipitation), many changes in communities’ water use (e.g. groundwater extraction) and land use (e.g. livestock grazing) contribute to drought. This creates challenges for ecosystems, which are impacted by and must recover from water stress under shifting and unfamiliar conditions, and for land managers, who must adapt to meet changing resource needs.

In a new study funded by the National CASC, a group of researchers, including scientists at the Alaska, North Central, Southwest, Northeast, and National CASCs, partnered with the Science for Nature and People Partnership (SNAPP) working group and others to understand the evolving nature of modern droughts throughout the United States. The group convened and led expert scientists, land managers, and decision-makers at workshops in each of the eight regional CASCs. Through group discussions, follow-up conversations, and a thorough literature review, they identified three major themes critical to understanding emerging drought patterns.

First, they underscored that drought conditions many species are currently experiencing are fundamentally different from historic droughts, making it hard for experts to predict how (or if) species will recover, and to anticipate when future droughts may take place. Next, they emphasized that modern droughts are more likely to be transformational, that is, to fundamentally change the species composition, structure, and function of ecosystems. Human and climate stressors are overwhelming ecosystems’ abilities to recover from droughts, causing many species to be replaced by new organism that often fill different ecological roles (for example, a forest being replaced by a grassland). Finally, they highlighted the vital role scientist-stakeholder partnerships will have in co-developing science to inform drought management strategies for drought prone areas.

This publication is part of the “Ecological Drought: Assessing Vulnerability and Developing Solutions for People and Nature” project funded by the NCASC. Further results of the CASC drought workshop series can be found on the CASC website.