Ecosystem services of temporary streams differ between wet and dry phases in regions with contrasting climates and economies

Abstract

<ol><li>Temporary streams are dynamic ecosystems in which mosaics of flowing, ponded and dry habitats support high biodiversity of both aquatic and terrestrial species. Species interact within habitats to perform or facilitate processes that vary in response to changing habitat availability. A natural capital approach recognizes that, through such processes, the 'natural assets' of all ecosystems deliver services that benefit people.</li><li>The ecosystem services of temporary streams remain largely unexplored, in particular those provided during ponded and dry phases. In addition, recent characterizations have focused on dryland systems, and it remains unclear how service provision varies among different climatic regions, or between developed and developing economies.</li><li>We use evidence from interdisciplinary literature to examine the ecosystem services delivered by temporary streams, including the regulating, provisioning and cultural services provided across the continuum from flowing to dry conditions. We focus on service provision during dry phases and wet-dry transitions, across regions with contrasting climates and economic development.</li><li>Provision of individual services in temporary streams may be reduced, enhanced or changed by surface water loss. Services enhanced by dry phases include provision of higher-quality subsurface drinking water and unique opportunities for recreation. Shifts between dry and wet phases enable groundwater recharge that mitigates water scarcity, and grant dry-phase access to sediments deposited during flowing phases. However, the accessibility and thus perceived value of these and other services varies considerably among regions. In addition, accessing provisioning services requires careful management to promote sustainable resource use and avoid ecological degradation.</li><li>We highlight the need for environmental managers to recognize temporary streams as aquatic-terrestrial ecosystems, and to take actions promoting their diversity within functional socio-ecological systems that deliver unique service bundles characterized by variability and differing availability in space and time.</li></ol>