Mesic areas comprise only 1-2% of the western landscape, but 80% of animals depend on them — including sage grouse and livestock. Learn why they’re important and how to conserve them.
Mesic areas like this riparian corridor on the Wyoming range comprise only 1-2% of the western landscape, but 80% of animals depend on them — including sage grouse and livestock.
What are “mesic” habitats?
Mesic is a broad definition of an ecological process that keeps places seasonally wet. In sagebrush country, these wet habitats include streamsides, wet meadows, springs and seeps, irrigated fields, and productive high-elevation rangelands.
In the West, snow melts in the spring, which floods and recharges many mesic areas. As runoff dissipates, the water slowly evaporates, leaving green places in the sagebrush desert. This annual event ensures mesic areas retain enough soil moisture for plants to grow throughout the hot summer, even when surrounding lands dry out and turn brown.
Why are wet areas important in sagebrush country?
All animals need water and the resources it provides, such as, plants, bugs, and more. Mesic habitats support 80% of wildlife in sagebrush country, but make up only 1-2% of sagebrush landscapes.
These wet, green places provide late-season resilience and drought insurance for people, wildlife, and livestock. After other water resources are depleted—when the snowpack is gone and there’s no rain in sight—mesic areas become hubs for wildlife and livestock.
Do sage grouse need mesic areas?
Sage grouse hens and their chicks rely on mesic sites—and the food they provide—in late summer when surrounding rangelands become less productive. Growing chicks need to eat nutrient-rich forbs and insects to reach maturity.
The chicks’ best shot at making it through the winter is to seek out “green grocery stores” late into the fall, before the first hard frost closes the door to these important food resources. Sage grouse thrive on sagebrush leaves during the winter. But studies have shown that chicks who have to transition earlier in the fall to a diet of solely sagebrush leaves have a lower survival rate.
How do we find these precious wet places across the West?
We can measure “greenness:” the drought resilient areas where plants grow in late summer. Satellite imagery picks up these sites very clearly, due to the a stark ecological contrast between dry and wet areas.
However, when scientists like myself started looking at the data, we realized quickly that those “green patterns” looked different each year. That’s because mesic areas are dynamic, changing over space and time based on annual climate and weather conditions.
To capture these changes, we used computer models to analyze 33 years of satellite archives. The result is the new Mesic Resources Layer on SGI’s Interactive Web App, a free online tool that allows anyone to pinpoint wet places across the West’s sagebrush range.
What can SGI’s mesic layer do for conservation?
The mesic layer helps landowners and resource managers visualize where scarce wet habitats are, as well as how they fluctuate through time. That information helps us target protection strategies in the areas that have been the most reliably wet, or restore degraded mesic sites to improve their productivity.
Basically, the mesic layer helps maximize the return on investment for conservation dollars by linking big-picture ecological dynamics with on-the-ground knowledge.
The dataset provides a snapshot of wet habitats across large landscapes down to an individual 10-acre parcel. For instance, you can push the “play” button on the SGI Web App mesic layer to watch the trends through time within an entire watershed or zoom in to view trends on a single ranch. You can also see a graph of how productive a certain area has been over time.
Since this targeting tool is based on satellite data that takes a 30,000-foot perspective of sagebrush landscapes, it’s important to pair it with what we know about the land right under our feet. Combined with site-specific information, this mesic habitat data can help landowners and resource managers make good decisions for the range.
What kind of research have you done in the past?
I’ve worked with several different agencies across a diversity of habitats in the West. With the U.S. Forest Service, most of my work focused on monitoring broad-scale landscape change influencing habitat needs of the Mexican spotted owl and willow flycatcher throughout the Southwest. I then spent time working for the U.S. Bureau of Reclamation as a scientist modeling water use by examining the interplay of riparian systems and agricultural irrigation along Colorado River. I’ve also worked for U.S Fish and Wildlife Service’s as a wetlands scientist and examined patterns of seasonal flooding and plant community response on National Wildlife Refuges.
My current position with the Intermountain West Joint Venture combines all I have learned of water, people, and wildlife on public and private lands. I feel grateful to have the opportunity to funnel these experiences into meaningful ecological research that span the landscapes of the western U.S.
Can you tell us about your hobbies?
My daily mantra includes trail running or cross-country skiing around Missoula, Montana, where I live with my lovely wife, Mary. I enjoy training and hunting over bird dogs, and I have three right now. When I’m not in the field, I find time to make furniture and play banjo.
Intermountain West Joint Venture conserves priority bird habitats in 11 western states through partnership-driven, science-based projects and programs. The IWJV was established in 1994 and is the largest of 18 U.S. Habitat Joint Ventures, which are collaborative, regional partnerships that work to conserve habitat for the benefit of birds, other wildlife, and people.
Role with Sage Grouse Initiative: IWJV provides scientific support for SGI’s new Mesic Conservation Strategy through Patrick Donnelly’s research. The IWJV also supports administrative and capacity-building for SGI’s Strategic Watershed Action Team, the two dozen field staff who work with ranchers to put in place conservation practices on private land. Through an agreement signed in 2016, IWJV is helping the Bureau of Land Management transfer SGI’s proactive, collaborative model to public lands, which will scale up win-win conservation across ownership boundaries.