A climate change indicator framework for rangelands and pastures of the USA

Abstract

Rangelands and pastures include grasslands, savannas, shrublands, and woodlands and are often maintained to support grazing animals. Rangelands and pastures cover more than one-third of the land area in the USA and a similar extent globally. The ecosystem goods and services associated with rangeland and pastureland include critical wildlife habitat, forage for livestock, amenities related to water conservation, sustainable soil functions, and soil stabilization and support a diversity of biota and livelihoods. This paper provides a framework for development of a socio-ecological system (SES)–oriented set of indicators for rangeland and pasture systems to support evaluation of impacts of climate and land use changes. These indicators will also serve to inform adaptive management practices. We present a rationale for using an SES approach to evaluate trends and vulnerabilities of rangeland and pasture systems and provide an example of a set of system indicators arising from the SES approach. The indicators include evaporative demand, land cover extent, aboveground plant biomass, human demographics (population age distribution), cattle numbers, and economic value of cattle products relative to total agricultural value. These indicators are not meant to be comprehensive but are offered to illustrate how they might be used in a SES approach to plan for, assess, and mitigate climate change impacts. The conceptual framework provides a systems perspective on the impact of climate change on the socio-ecological dynamics of rangeland and pasture systems including measures of the resilience and vulnerability of ecosystem services with respect to the six indicators. The article focusses on livestock production in rangeland ecosystems, recognizing that additional work is needed to address pastures and other ecosystem services. Examples of the types of regional information associated with the indicators are provided. Guidance for future efforts in indicator development is offered. This framework will serve to guide future development of indicators for rangeland and pasture components of a larger national effort of indicators.