Rangeland Ecosystem Services in the Northwest
The four main categories of ecosystem services, as described in the Millennium Ecosystem Assessment in 2005, and select examples from Northwest rangelands.
Rangelands are dominated by grasses, forbs, and shrubs and comprise more than 30 percent of the land area across Washington, Oregon, and Idaho and over 20 percent of Alaska. Northwest rangelands occur in several different ecosystems: shrubland, grassland, prairie, savanna, woodland, and tundra. They offer benefits from livestock grazing to wildlife habitat, recreation opportunities, and carbon storage. Rangelands in the Northwest are also a cultural resource for Indigenous peoples, ranchers, and outdoor enthusiasts. These benefits, or ecosystem services, can be broken down into the following four interdependent categories:
Supporting services are the basic natural processes in rangelands that all other ecosystem services depend on. An example is soil formation.
Regulating services are the benefits from supporting services that have a more direct effect on people’s lives, such as water filtration.
Provisioning services are the tangible benefits that rangelands provide, such as livestock production and fresh water.
Cultural services are nonmaterial benefits, such as a sense of place and spiritual connections to the land around us.
Northwest rangelands include several different ecosystems.
Climate change is affecting Northwest rangelands. Higher temperatures, changes in rain and snow patterns, and more frequent extreme events are already changing rangeland health and productivity. These changes affect how well rangelands can provide important benefits. Past and ongoing disturbances, such as the effects of heavy livestock grazing, invasive annual grasses, and wildfire, have made rangelands more susceptible to climate change effects. Understanding how climate change affects rangeland ecosystem services can help managers prepare for and adapt to future conditions.
Here we discuss key examples of rangeland ecosystem services and how climate change is affecting them or may affect them in the future. We chose these ecosystem services because they are important to rangeland managers in the Northwest.
Water Quality and Quantity
Rangeland plants such as juniper, big sagebrush, and bluebunch wheatgrass help keep water in the John Day River watershed clean and flowing to nearby communities of John Day, Canyon City, and the Confederated Tribes of the Warm Springs. The watershed is also home to one of the largest remaining populations of wild Chinook salmon and steelhead in the Columbia River Basin.
Rangelands support a clean and adequate water supply. Plant roots stabilize soil, preventing it from eroding into waterways. Rangeland plants and roots also intercept rainfall and slow down water droplets, giving the water time to soak into the ground. This helps to replenish water stored underground and to maintain consistent streamflow. Rangeland soil also works like a natural filter removing pollutants, sediment, and excess nutrients from water before it enters rivers and streams. Rangelands contribute to water quality as a regulating service and to water quantity as a provisioning service.
Climate change is affecting the ability of rangelands to perform these functions. Changes in precipitation, such as more intense rainfall events, can cause more water to run off and less water to seep into the ground and refill underground supplies. This is especially a concern in Alaska, where precipitation may increase. Too much rain at once can make it hard for shrubs and grasses to prevent erosion. Warmer temperatures and declining snowpack may result in lower summer stream flows and warmer stream temperatures. These conditions can harm fish habitat and reduce water availability for communities. More frequent and extreme disturbance events, such as wildfire and flooding, can damage plants and leave soil exposed. This may also increase erosion from rangelands into waterways and affect water quality.
Pollinators
Northwest rangelands support diverse communities of pollinators, including bees, moths, butterflies, wasps, and flies that facilitate plant reproduction. Pollinated plants are the foundation of rangeland food webs, providing food and habitat for wildlife and livestock alike.
Climate change is projected to alter pollinator habitat and flower availability on rangelands. Pollinator host plants are adapted to drought and wildfire, but these events are becoming more frequent, which can alter pollinator habitat. For instance, extreme drought and high-intensity fire can increase the spread of invasive species, displacing pollinators’ native host plants. Some pollinators may move farther north, which could separate plants and pollinators from one another. Warmer temperatures are causing many rangeland plants to flower earlier. If pollinators do not appear earlier, plants may bloom before pollinators can access them.
Rangeland Products
Rangelands on the Seward Peninsula, Alaska.
Rangelands support livestock production, including cows, sheep, reindeer, hogs, and goats. In the dry Intermountain West, irrigated pastures provide food for cattle. Wetter areas west of the Cascades support livestock in grazed woodlands or in non-irrigated pasturelands seeded with non-native plants. On the Seward Peninsula tundra in northwestern Alaska, native communities graze reindeer for their meat and hide. Livestock is a major economic driver in the Northwest, bringing in $13.14 billion of sales across Idaho, Oregon, and Washington in 2022.
Rangelands in Washington, Oregon, and Idaho are projected to see an increase in plant growth and food availability for livestock. Alaska’s tundra is also showing increased productivity because of warmer summer temperatures. However, drought conditions are projected to increase in the future. High temperatures during drought are expected to cause heat stress for both livestock and plants. As temperatures rise, some plants eaten by livestock are projected to emerge earlier (by up to 17 days), while others may emerge and flower later. These changes in climate may result in a shorter growing season and limit the amount of food available to livestock.
Cattle grazing east of the Steens Mountain in the high desert of southeastern Oregon.
Warming temperatures are also causing pests to emerge earlier in the season. In some cases, these changes can make pesticides or biocontrol less effective. For example, the cereal leaf beetle is a pest that harms pasture grasses. A parasitic wasp is used as a biocontrol to reduce this pest. Warmer temperatures are causing cereal leaf beetles to emerge before the parasitic wasp, leaving a period during which grasses are damaged. Increasing temperatures also make rangelands more susceptible to the encroachment of highly flammable annual grasses, which in turn makes rangelands more prone to wildfire.
Traditional foods and practices
A camas prairie in the Sawtooth National Forest, near Fairfield, Idaho.
The plants and animals found on rangelands have spiritual, aesthetic, and cultural importance. Rangelands are home to several plants that are harvested for cultural and medicinal uses. For instance, common camas is a prairie flower with a starchy bulb that is harvested by Northwest tribes as a food source using traditional methods and knowledge.
Grassland ecosystems also serve as important hunting grounds for many Northwest tribes. For instance, the Nez Perce Tribe harvests elk and mule deer using traditional hunting practices in rangelands. Some Alaska Natives have a close relationship with caribou on the Alaska tundra and depend on them for food and clothing.
As the climate continues to change, cultural connections between humans and rangelands may be affected. Changes in temperature and precipitation could affect the growth of culturally important plants like common camas. Following germination, young camas seedlings need moist soil conditions throughout the spring. Without these conditions, camas plants could remain inactive for years, affecting harvesting schedules. Rising temperatures also affect wildlife. Lower snowpack and earlier snowmelt can change the availability of food and disrupt how elk move from place to place. These climate-driven changes not only affect rangeland ecosystems, but also the cultural practices that are closely tied to rangeland species.
Recreation
Northwest rangelands provide many different ways for people to enjoy the outdoors, bringing visitors from all over country. Individuals can hike, backpack, bike, and ride horses in these areas. Rangelands are also known for their wildlife viewing opportunities. Areas such as the Curlew National Grassland offer year-round birding and the chance to witness the famous mating dances of greater sage-grouse and sharp-tailed grouse in the spring. The abundance of wildlife in rangelands also makes them an ideal location for recreational hunting. Recreation in rangelands provides economic benefits to communities across the Northwest. The Sawtooth National Forest, for example, has shrublands and grasslands that attract visitors from around the country. In 2020, each group of visitors to the Sawtooth spent an average of $741, and the forest welcomed over 1,000 visitors that year.
Climate change is reshaping the recreational landscape of rangelands. Rising temperatures and longer periods of drought could result in reduced native grass and forb growth. These conditions can also lead to more intense wildfire seasons affecting rangeland wildlife species and outdoor opportunities. Greater sage-grouse depend on big sagebrush for food and cover, but more frequent wildfires and drought can alter greater sage-grouse habitat. Higher temperatures may also change when visitors want to visit rangelands. Activities such as hiking and camping may become unpleasant or dangerous during periods of very hot weather.
Carbon
Rangelands contribute to the global carbon cycle by cycling and storing carbon. Carbon cycling occurs as plants and trees take in carbon dioxide from the atmosphere and use it to grow. Carbon cycling is a supporting ecosystem service. Carbon storage occurs when carbon is kept in plants, trees, and soils, and is an example of a regulating ecosystem service. In rangeland ecosystems, carbon is stored aboveground in leaves, branches, and flowers, and belowground in roots and soils.
In the Northwest, over 80 percent of rangeland carbon is found below ground. The amount of stored carbon depends on the climate, soil type, aboveground vegetation, and disturbance history. In cool, wet places, soil carbon is mainly in the form of organic matter from broken-down plant material. In dry shrublands and grasslands, soil carbon is composed of broken-down plant material and mineral carbonates that build up over centuries as rocks break down. In Alaska, most rangeland carbon is stored in permafrost, a layer of soil that remains frozen year-round. Globally, permafrost is estimated to store more carbon than the atmosphere.
In rangeland ecosystems, climate change is intensifying feedback loops, which affects both the amount of carbon stored currently and the amount that can be stored in the future. Hotter and drier conditions can lead to more frequent and intense wildfires. Wildfires create favorable conditions for invasive annual grasses to grow. Invasive annual grasses are non-native grasses that grow and die within the same year. Cheatgrass, an invasive annual grass, grows quickly and often outcompetes native grasses, especially after a fire. Cheatgrass dries out quickly and creates a layer of flammable fuels that make future wildfires more likely. This cycle—fire creating favorable conditions for cheatgrass, and cheatgrass increasing fire risk—creates a feedback loop. Cheatgrass has shallow roots and minimal biomass. Because of this, it does not contribute much carbon to the ecosystem compared to native grasses that can live for many years. As the abundance of native, deep-rooted grasses declines, less carbon is stored in deep soil layers (>30 cm or 11.8 inches). Repeated fires can further reduce the amount of carbon stored. Over time, repeated fire may inhibit cheatgrass regrowth.
Adaptive Management
Rangeland managers can use a variety of management practices to ensure that rangelands still provide ecosystem services as the climate changes. For example, managers can change how many livestock graze and where and for how long they graze to help forage plants grow back. Integrated weed management and controlled burning can promote fire-adapted forage plants and reduce invasive annual grasses. Restoring rangeland wetlands and riparian areas can help water soak into the ground and improve forage production. Climate change is projected to affect rangelands in the Northwest, but understanding these effects can help rangeland managers adapt to changing conditions and maintain the benefits that rangelands provide.
The following resources describe land management activities that can promote ecosystem services in Northwest rangelands:
Many rangeland managers are already using adaptive management strategies to maintain ecosystem services in a changing climate. Rangeland researchers are also exploring additional strategies for rangeland restoration. The following case studies highlight managers and researchers in the region who have implemented one or more of the adaptive management activities listed above:
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