New resource sheds light on tree encroachment on sagebrush ecosystems

Extensive research shows that native conifers, such as juniper and pinyon pine, have increased their footprint on the landscape at an unprecedented rate over the past 150 years, especially in places such as the Great Basin, where 1 .1 million acres have grown from the bush. or rangelands to woodlands since 2000. This accelerated conversion of scrub and grassland ecosystems to woodlands has undesirable effects, including the loss of unique wildlife and wildlife habitats, reduced water availability, and increased runoff and erosion, less land available for livestock grazing and greater fuel loading for forest fires.

A new website from the PJ (pinyon-juniper) Encroachment Education Project collaboration sheds some light on the matter. The site is also a resource for those trying to manage this threat, particularly in the Great Basin, where invasive pinyon pines and junipers are invading sagebrush ecosystems and contributing to the decline of species at risk such as the western grouse. sagebrush.

“The thrust of this project is to provide science-based insights into the ecology and impacts of the problem, and the collaborative work being done to address it,” said Christina Restaino, a natural resources specialist at the University of Nevada, Reno Extension. , the organization carrying out the project. “The website is intended to help people understand the issue and to serve as a clearinghouse of information to help land managers, professionals and agencies across the West in their collaborative efforts.”

Restaino, who is also an assistant professor in the University’s College of Agriculture, Biotechnology and Natural Resources, said a new report from the US Geological Survey and the Western Association of Fish & Wildlife Agencies identifies the tree encroachment as one of the top three threats to sagebrush ecosystems. – the other two being invasive species and land use planning.

The website launched today and includes sections explaining the ecology of how and where the conversion occurs, as well as the impacts of converting sagebrush range to forests. The “Resilience in Action” section shows the projects underway in the West to deal with the problem. Finally, there’s an impressive “See the Science” section, where online viewers can search a database with over 400 peer-reviewed articles on an interactive map for information on the matter by location, topic, keyword or year.

Project partners worked for two years to build the website, diving into research; organize multiple working sessions with stakeholders; work with web designers to create an organized and easy-to-navigate site; and work with a technical illustrator to provide clear and accessible graphics for the site. Project partners include the USDA Natural Resources Conservation Service’s Working Lands for Wildlife partnership, the Bureau of Land Management, and the Intermountain West Joint Venture’s Partnering to Conserve Sagebrush Rangelands initiative.

“Communicating why more trees everywhere isn’t always a good thing is a real challenge for land managers tasked with conserving non-forest land,” said Jeremy Maestas, who is part of the task force and an expert in Sagebrush Ecosystem at USDA-NRCS. “With Extension, we were able to create a website that helps a wide audience understand the science behind the problem.”

Besides the devastating effect on sagebrush-dependent wildlife, Maestas points out that the encroachment also has economic impacts.

“In Intermountain West, 90% of tree encroachment has occurred in sagebrush shrubs, a habitat type that has already been cut in half due to a wide variety of threats. Species like the sage grouse, which are found nowhere else in the world, abandon breeding habitats when there are only a few trees per acre. Invasive trees also suck valuable soil moisture needed in arid lands to grow other native grasses and wildflowers, which means less food and cover not only for wildlife, but also for the livestock that support it. western rural agricultural economies.

Mandi Hirsch, sagebrush collaborative conservation specialist for the Intermountain West Joint Venture and leader of the Partnering to Conserve Sagebrush Rangelands initiative, is also part of the project’s working group. She knows firsthand the impact that tree encroachment on rangelands can have on ranchers. Hirsch is a breeder at heart and by profession who now also works for the conservation and sustainability of rangelands in the West.

“The conservation of a single species like the sage-grouse is very important, but it is only part of the bigger picture when managing natural resources at the landscape scale. What many people don’t realize is that there are many other potentially devastating effects of encroachment, including jeopardizing our pastoralists’ livelihoods and their ability to produce food. I really think this website can help people understand this and all the other impacts of this encroachment. And I think it will be a great continuing resource for those trying to do something about it.

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