Climate Change and...
Changing desert shrublands, past and present.
The unexpected science behind managing our natural resources
About those involved
The Scientists featured in this story are a part of the Grassland, Shrubland, and Desert Ecosystems Program (GSD) of the Rocky Mountain Research Station. They work to develop the science needed to help sustain and restore these valuable ecosystems that face a myriad of threats. Find out more about each of them here.
Karen Bagne is a cooperator with the Rocky Mountain Research Station in their Albuquerque Lab. She is a wildlife biologist and studies how wildlife species respond to changes in forest structure. She is also working on species assessments to identify those species most vulnerable to climate change. Find more on Karen's work here.
Dr. Deborah Finch is the program manager of the Rocky Mountain Research Station's Grassland, Shrubland and Desert Ecosystems Science Program. Her interests focus on the ecology and restoration of ecosystems and conservation of species.
"Understanding how plants have responded to changes in climate in the past can help predict how they may respond to changes in the future."
The oak and the reed: a fable
Woodcut by Bernard Saloman from Lyon's 1547 Aesop's Fables
The Oak and the Reed: A Fable
A strong oak tree brags to a nearby patch of reeds about its strength noting that the reeds are so weak that the smallest wren is too heavy a load to bear. Later, a violent storm erupts and the oak is toppled by the strong winds while the reeds bend and bounce back unharmed...Read More
The Oak and the Reed: A Fable
Oaks and reeds have very different ways of coping with strong winds and other forces, but are also both valued resources. National Forest and Grassland managers are tasked with protecting a diverse set of resources on public lands that have a wide range of responses to their environment. This task is becoming increasingly challenging as the climate brings us stronger and more variable weather patterns. Scientists at the Grassland, Shrubland and Desert Ecosystems program (GSD) of the U.S. Forest Service are working on solutions to help land managers prepare for the different ways in which climate will affect our diverse forest and grassland resources.
One way we can use science to help management, is to predict how different species will respond to climate change – which will be like oaks and which will be like reeds. This knowledge prepares us for the future. GSD scientists created a vulnerability scoring system, SAVS, so that managers can identify which species will be more resilient or bounce back and which will be more vulnerable or topple under future climate conditions. SAVS can be useful when little information is available on a species’ climate change response or a large number of species need to be prioritized. In addition, lead author Karen Bagne notes, “this tool is not just about high or low scores but is also about a process to highlight the many ways climate affects species.” These predictions can then be used to find early actions to protect a species from an impact, such as strong winds, or improve a species ability to bounce back.
There is a lot we don’t know, but sometimes just learning what we don’t know can help. Compared to the forests many of us associate with public lands, grasslands, shrublands, and deserts receive little attention despite their high value and the greater threat from fragmentation and development. GSD scientists from six western states recently produced a comprehensive review and needs assessment on climate change issues in these important ecosystems. GSD has also taken a closer look at the Southwest and reviewed the available climate change assessments across scales and topics. Not only do these syntheses identify key climate issues and robust solutions, but they also highlight areas where more research and assessment is needed. And so the work of GSD and its partners continues.
As the winds of change intensify, we need not have a landscape comprised of only reeds if we choose. Working together, scientists and managers can develop solutions to help preserve and manage all of the resources we value.
It Takes Two
Science can provide important information for making good management choices, but only if scientists know what managers need. In an effort to improve management of the Great Plains under future climate change, scientists at GSD teamed up with grassland managers. A workshop was organized with two parts: one to communicate the latest climate change science relevant to the Great Plains and two to discuss the science needs of grassland managers. Science findings were presented via a webinar and were well received by managers as well as other scientists. During workshop discussions, it was clear, however, that much of the science information needed to take the next step and translate science findings into specific management recommendations across a wide range of fields. "Don't just tell us what is going to happen. Tell us what it means" was a common plea. Recordings of the webinar talks are available online.
Together scientists and managers can find creative ways to use available tools and find solutions that will sustain or enhance our public lands. GSD collaborated with Coronado National Forest managers and the University of Arizona to select and score 30 priority management species and used the SAVS scores (see preceding story) in conjunction with species distribution data to create a picture of vulnerability across the southeastern Arizona landscape. Vulnerability scores were integrated with spatial data to expand the scale of decision-making from a single species to a landscape. Interesting results include high vulnerability for species such as the elegant trogon (Trogon elegans) and Tarahumara frog (Rana tarahumarae), and also for upland species such as Northern gray hawk (Buteo nitidus plagiata) and Gould's wild turkey (Meleagris gallopavo mexicana).
Scientists at the Grassland, Shrubland and Desert Ecosystems Science Program (GSD) of the U.S. Forest Service Rocky Mountain Research Station continue to work on solutions to help land managers prepare for the different ways in which climate will affect our diverse forest and grassland resources.
Blackbrush — the name may sound unfamiliar, but you would probably recognize this plant as part of iconic western landscapes in places like the Grand Canyon and Joshua Tree National Park, perhaps misnaming it as sagebrush. It may not grab your attention, but blackbrush or Coleogyne ramosissima is an important player in desert ecosystems, dominating the transition from warm to cold deserts of the western U.S. and providing forage and cover for bighorn sheep as well as seeds for a variety of birds and small mammals. It is also a key research subject, revealing how climate shapes the world around us.
National Forest and Grassland managers are tasked with protecting a diverse set of resources on public lands that have a wide range of responses to their environment. This task is becoming increasingly challenging as climate changes lead to stronger and more variable weather patterns. Understanding how valued species such as blackbrush have changed in the past and how they may change in the future can help guide managers as they make decisions. Two Rocky Mountain Research Station (RMRS) scientists in Provo, Utah, Bryce Richardson and Susan Meyer, examined blackbrush DNA and combined these findings with previous studies to create a picture of how blackbrush populations responded to warming following the last glacial period. Richardson notes, "the fundamental interaction between organisms, or organisms and their environment, is through their genes." Previous to this study, blackbrush had been thought by many to be a relict species, a species with little genetic diversity better adapted to past conditions, implying little adaptability to change. Instead, genetic analysis revealed high genetic diversity representing two distinct population groups, suggesting that blackbrush persisted through past climate change events during the Early Holocene and Late Pleistocene with large populations and a widespread geographic distribution.
In addition to the pattern of genetic variation, evidence for past distributions comes from ancient packrat middens where packrats have deposited debris that preserve local plant and animal communities (see more papers on this here). These middens contain a wealth of information and under the right conditions may preserve a record of the local environment going back more than 50,000 years. When middens are examined across a landscape, they reveal patterns of past distributions of plants and animals. Following the last ice age, blackbrush appears to have shifted northward and upward in elevation. Combined with the genetic evidence, the scientists concluded that the two blackbrush population groups likely diverged during this shift because the high elevation plateaus in southern Utah pose a barrier to gene flow and colonization.
Researchers Rosemary and Burt Pendleton of Albuquerque, New Mexico and Stan Kitchen of Provo, Utah, are also contributing to our understanding of ecological differences by using a "common garden" approach to examine blackbrush adaptations to local conditions such as winter temperatures and monsoonal rains. Common garden experiments typically take plants from different native environments and rear them in a common area, in this case providing information on how different populations of blackbrush might survive and grow under novel climatic conditions. Rosemary says, "Understanding how plants have responded to changes in climate in the past can help predict how they may respond to changes in the future". Their results showed a great deal of variation in blackbrush responses to weather conditions.
Altogether, much of this research shows that blackbrush’s genetic diversity may help this species adapt to future climate conditions. But as in the past, there are physical barriers that will limit dispersal. In addition, blackbrush establishes poorly following fire. Therefore, although blackbrush has successfully migrated in response to climate in the past, the expansion of exotic annual grasses that have led to an increase in wildfires will likely limit natural migration, and more active management may be required. Recently Rose, Burt, Susan Meyer and others evaluated how blackbrush could be successfully restored given problems with major fires and invasive plant species. They concluded that restoration focused at higher, and cooler, elevations would be advantageous as global temperatures warm.
Understanding the past helps scientists and managers predict where blackbrush will shift in the future and where natural migration is unlikely to occur, which will influence not only blackbrush, but animal species that depend on it as well. Knowledge of local adaptations and response to disturbance in the present can direct managers towards successful management actions such as establishing protected areas, collecting seed for restoration, and reducing fire frequency. Interactions among temperature, precipitation, genetic adaptations, topography, and disturbance illustrate the complexity of predicting species response to climate change, but also the value of science to successful management of natural resources.
- Climate change in grasslands, shrublands, and deserts of the Interior West
- Blackbrush seed (Coleogyne ramosissima Torr. [Rosaceae]) following long-term storage [pdf]
- Paleoclimate effects and geographic barriers shape regional population genetic structure of blackbrush (Coleogyne ramosissima: Rosaceae)
For more information:
See the January 2013 Science You Can Use Bulletin Upwardly Mobile in the Western U.S. Desert: Blackbrush Shrublands Respond to a Changing Climate [pdf].