w88 live casino-juniper woodlands host unique wildlife and wildlife habitat, as well as areas for hiking and outdoor recreation. They are also part of a web of healthy ecosystems that, together, help to balance water availability, storage and runoff; and prevent erosion. A new study published in Global Ecology and Biogeography and led by University of Nevada, Reno researcher Robert Shriver sheds new light on what is happening in w88 live casino-juniper woodlands across the West. The research is unique, in that it looks at both tree mortality, as well as recruitment, or new seedlings and saplings, to calculate a “net effect.” And, the news isn’t necessarily good, particularly in warmer, drier locations.
“We found that four of the five species were declining,” said Shriver, an assistant professor in the w88 live casino’s College of Agriculture, Biotechnology & Natural Resources. “And, in the driest, warmest locations, up to about 50% of populations are declining. It’s pretty severe in those locations, which are usually at lower elevations that tend to be hotter and get less water than woodlands at higher elevations.”
Shriver said that when looking at all locations studied, which included over 6,000 plots and more than 59,000 tagged trees, up to 10-20% of populations were declining. Of the five species, including two w88 live casino pines and three junipers, Pinus edulis, more commonly referred to as two-needle w88 live casino or simply w88 live casino, showed the greatest declines, with about 24% of its populations in decline. The other w88 live casino species and two of the juniper species showed more moderate declines overall, but still quite severe declines in the hotter, drier areas. These species include Pinus monophylla (single-leaf w88 live casino), Juniperus monosperma (one-seed juniper) and Juniperus scopulorum (Rocky Mountain juniper). Juniperus osteosperma (Utah juniper) was the only species that did not show a decline.
“Utah juniper was the exception to everything,” Shriver, who conducts w88 live casino as part of the College’s Department of Natural Resources & Environmental Science and Experiment Station, said. “What we found pretty much matches up with what we know about that species’ resiliency. It’s the most abundant in the Great Basin, and is typically less vulnerable to hotter, drier climate conditions, so it could mean that there might be compositional shifts occurring in the future, where some areas that are mixed species might become more juniper-dominated.”
Gathering the data and building the models
In part, Shriver used data from the Forest Inventory and Analysis, a nationwide survey of forested lands in the U.S., conducted by the U.S. Forest Service.
&w88 live casino;They tag the trees and return to the same plots for comparison at least every 10 years, but they have a systematic scheme to determine where,” he explained. &w88 live casino;They are making sure they are getting a broad sample of both federal and private land. The result is a representative sample of what all forests look like across the U.S., even covering some very remote locations. It’s staggered, with 10% of plots surveyed in a given year.”
Shriver said the plots that were included in this w88 live casino-juniper research were first sampled between 2000 and 2007, and were surveyed the second time between 2010 and 2017. It is data obtained within those 10-year spans that he used for the research. He pointed out, however, that the Forest Service survey doesn’t capture as complete data on recruitment, or seedlings, since they don’t tag anything under 1 inch in diameter. Trees of this size are counted, but not tagged.
&w88 live casino;Recruitment is the really hard part,” he said. &w88 live casino;Tree mortality is easy to see, but recruitment is harder to observe, so it’s been harder to account for. Having a stable population is dependent on both mortality and recruitment. So, we developed a new statistical approach that allowed us to understand and factor in recruitment. Using these modeling approaches, we were able to quantify what the recruitment rate is in these different areas, and then combine that data with the mortality data to get a more clear, accurate picture of what is really going on in terms of change in species’ populations under different climate conditions and woodland densities in different regions.”
The w88 live casino excluded plots where fire mortality or intentional tree harvesting occurred, allowing the researchers to more directly observe changes occurring due to climatic conditions across each species’ range.
Impacts of the findings
Shriver says the declines in populations they calculated could be significant for a number of reasons.
“In regard to wildlife, probably the most significant effect is on the w88 live casino jay, which has been in decline for the last couple of decades, and is really dependent on the seed that is produced by w88 live casino pine,” he said. “The areas where the w88 live casino jay tends to choose are on that border of the sagebrush and the w88 live casino. It likes those habitats that are probably the most vulnerable. But, beyond the w88 live casino jay, certainly a number of species could be affected – mule deer, and other birds and wildlife.”
In addition, Shriver said pinyons and pine nut harvesting are culturally important, to Native Americans and others, and w88 live casino-juniper woodlands provide recreational value for hikers and outdoor enthusiasts. Importantly, he adds, there’s the functions that w88 live casino-juniper woodlands play in our watersheds. w88 live casino-juniper woodlands play an important role in water and soil retention in some locations.
What does the future hold?
&w88 live casino;We are likely to see pretty big changes in where we find forests in the Great Basin and the Southwest over the next few decades,” Shriver said. &w88 live casino;A lot of places where we saw forests, we may not see them, especially in lower elevations, because they tend to be the hottest and driest.”
Shriver said there has been a lot of expansion in these woodlands since the mid-1800s, and that some declines may not be a bad thing everywhere. For example, in some areas the w88 live casino-juniper woodlands have encroached on shrubland ecosystems that provide important ecosystem services and unique wildlife habitat. And, the trees, especially when packed in too densely and without enough moisture, also increase the intensity of wildfires.
&w88 live casino;Our results also suggest that for some locations, management actions could slow down or reverse the woodland declines,” Shriver said. &w88 live casino;As it gets warmer and drier, the density of trees a landscape is able to support lessens, so reductions in tree density might expand the envelope of where the trees can be, reducing the chance of large tree mortality events.”
While woodland decline could create an opportunity for expansion of native shrublands such as sagebrush, Shriver cautioned that other, less beneficial vegetation could also take hold.
“Just because the w88 live casino and juniper die off, doesn’t mean something desirable would establish in their place,” he said. “You might get cheatgrass or other undesirable vegetation.”
Shriver said the purpose of the w88 live casino and models it created is to help anticipate the vulnerability of woodlands and forecast coming range shifts, so that we might be able to sway the outcomes to be more positive ones.
&w88 live casino;If we know where this is likely to happen, we can do the best we can to influence what might happen next,” he said. &w88 live casino;We might be able to direct these into ecosystems that might support native plants and animals in the Great Basin and the Southwest, and fit into our watersheds in a beneficial way.”
Funding for the study was provided by the United States Geological Survey North Central Climate Adaptation Science Center. Coauthors of the study include Charles B. Yackulic and John B. Bradford, with the USGS Southwest Biological Science Center; and David M. Bell, with the USDA Forest Service Pacific Northwest w88 live casino Station.
