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10 Things You May Not Know About Plants and Forests

Spring is here and in many places across the country, trees are beginning to bud, flowers are blossoming, and the world is starting to look a little more colorful. Look a little closer though and you’ll find that many plants are facing challenging times.

Spring is here and in many places across the country, trees are beginning to bud, flowers are blossoming, and the world is starting to look a little more colorful. Look a little closer though and you’ll find that many plants are facing challenging times. From increases in pesky tree eaters to more frequent and severe droughts, there are many impacts of climate change on plants and forests that resource managers, tasked with conserving plant resources, have to contend with. However, the forecast is not all doom and gloom. Scientists across the country are hard at work providing managers with the science they need to make important conservation and adaptation decisions. Learn more about our work with these 10 examples from the National and Regional Climate Adaptation Science Centers.

Two mule deer in a field of yellow and green
(Credit: Tom Koerner, Fish and Wildlife Service. Public domain.)

1. Spring “Green-up”: Big game animals closely time their migrations to “green waves” of spring forage. The “green-up” refers to the annual growth pattern of high quality, new vegetation that occurs during the spring. In 2016, NCASC-supported scientists were able to match movements of bighorn sheep, mule deer, elk, moose, and bison with this “green wave” of vegetation. A newer study, published in 2017, focused specifically on how well migratory mule deer “surf the green wave”. “These deer have an almost uncanny ability to keep pace with the spring timing of the greening. And that allows them to get the highest quality forage, when plants are first greening up,” said Matt Kauffman, lead on this project.

2. Wild Berries: Science can help managers identify prime areas for wild berry restoration. Wild berries are a valued traditional food for tribes of the Chugachmiut Tribal Consortium in the rural Chugach region of south-central Alaska. From 2008 to 2012, wild berries in this region were decimated by an outbreak of moths.The outbreak is thought to have been brought about by warmer temperatures, which allowed a greater number of moths to survive the winter. In response, scientists supported by the Alaska and Northwest CASCs set about developing maps and models to help tribal and other land managers target areas where berry restoration efforts are most likely to be successful and where the berries will be protected from future insect outbreaks.

3. Urban Trees: Lack of water can harm trees and exacerbate problems caused by pests and heat. In a 2014 publication, scientists supported by the Southeast CASC found that warmer temperatures can limit the impacts of beneficial wasps which would normally help keep some insect pest populations in check. A new paper, released in March 2018, also points to lack of water as a key stressor for urban trees. This study found that urban trees can actually survive increased heat and insect pests fairly well - unless they are thirsty. "This [work] is important because trees need to grow in order to perform valuable ecosystem services, such as removing pollutants from the air and storing carbon," says Steve Frank, co-author on the paper.

Maui silversword on Haleakalā volcano
Beautifully striking contrast between the pale Maui silversword plant and the red volcanic rock of Haleakalā volcano. 

4. Native Hawaiian Plants: Several hundred plant species found only in Hawaiʻi are threatened by shifting climate patterns.Researchers have found that many of the plants that make a visit to Hawaiʻi’s national parks so memorable are increasingly imperiled by shifting climate patterns, particularly lower rainfall. This includes the Haleakalā silversword, a silver-green distant relative of the daisy found on the summit of Maui’s Haleakalā volcano. Scientists supported by the Pacific Islands CASC modeled the outlook of the state’s unique plants and found that many are likely to be lost in the wild within the next 100 years if populations continue to decline. The silver-lining is that now these findings can be used to inform management and conservation efforts for these vital parts of Hawaiian ecosystems.

5. Changing Coastal Wetlands: Sea-level rise is not the only change expected to affect plant communities in coastal wetlands.Scientists supported by the South Central and Southeast CASCs found that changes in rainfall and temperature are predicted to transform wetlands in the Southeastern U.S. and Gulf of Mexico, regardless of sea-level rise. For example, some salt marshes are predicted to become mangrove forests, while others could become salty mud flats. These shifts in vegetation could affect the ecological and economic services wetlands provide to the communities that rely on them, such as protecting surrounding communities from storms and coastal erosion and supporting fisheries and wildlife.

6. Sugar Maple: Maple syrup is in a sticky situation as U.S. maple producers report earlier and more variable syrup tapping seasons.Warming temperatures, changes in precipitation, and changes in freeze and thaw cycles will impact maple trees and syrup production. Northeast CASC-supported scientists and partners identified that climate changes will reduce the number of trees available to tap, shorten the tapping season, and decrease sap quality and quantity. However, the sweet side of the story is that industry is adapting to these changes by improving sap collection technology, diversifying the species of trees tapped, and alleviating other environmental stressors.

7. Old-Growth Forests: As temperatures warm, old-growth forests might offer refuge to some birds. In a recent study, supported by the Northwest CASC, scientists looked at 13 bird species and found that old forests with large trees and a diversity of tree sizes and species may offer refuge to some types of birds that are threatened by a warming climate. "Managers hoping to combat the effects of climate change on species' populations may now have an additional tool - maintaining and restoring old-growth forest,” said the study’s lead author, Matthew Betts of Oregon State University. Additional research in the future may also be able to help managers identify the specific features of mature forests that buffer the effects of warming on birds.

8. Whitebark Pine: Habitat for the whitebark pine tree is predicted to decrease in the Northern Rockies. In a study supported by the North Central CASC, scientists assessed the vulnerability of trees in the Northern Rocky Mountains and found that whitebark pine will lose habitat due to climate shifts. Additionally, a separate study supported by the Northwest CASC also found that warmer winters and lower rainfall led to a higher chance of mountain pine beetle infestation in the trees. A decline in whitebark pine could impact bear habitat, soil stability, and snowmelt runoff in areas like Yellowstone. Managers can use this research to inform restoration efforts, such as replanting in areas that may remain cold enough to kill the beetles, at least for many years.

Image of a fire burning behind treeline, with a stream in the foreground
Black Forest Fire, Colorado - Credit: USDA

9. Forests, Drought, & Fire: Prescribed fire may improve forest resistance to drought. In the western U.S., severe drought and rising temperatures have caused increased tree mortality and complete forest diebacks. Scientists supported by the Southwest CASC are examiningwhether a common forest management tool, prescribed fire, can be implemented to help forests better survive drought. In 2014, the researchers compared forests in the Sierra Nevada and found that burned plots had significantly lower probability of mortality compared to unburned plots during drought. The findings support the idea that reduced competition due to fewer trees in burned areas may help the remaining trees better survive drought.

10. Alpine Treelines: As temperatures rise, alpine treelines in Alaska are changing. Alpine treelines are found at high elevations and mark the limit above which trees can no longer grow (due to cold temperatures, snow conditions, etc.). Snow-covered alpine zones (the areas above the treelines) are popular for skiers and recreationists and are also an iconic part of the Alaskan landscape that brings thousands of tourists to the state every year. Alaska CASC scientist Jeremy Littell is working to understand how treelines and glaciers in alpine areas may change in a warmer world. These changes could have consequences for downstream environments, important natural resources, and the state’s economy.

This year, 2018, marks the 10-year anniversary of the establishment of the National Climate Adaptation Science Center (NCASC). In those 10-years, the eight regional Climate Adaptation Science Centers (CASCs) were established, and together, NCASC and the CASCs funded over 425 science projects and built a network of research partners, resource management stakeholders, interdisciplinary staff, fellows, and early career researchers.

In celebration of our work and accomplishments over the last 10 years, we have launched a monthly series featuring “10 Things You May Not Know” about different topics our science has focused on, including drought, glaciers, and wildfire.