Mangrove forests and salt marshes perform a variety of beneficial functions: they protect coastlines from storms and erosion, improve water quality, and offer habitat for fish and wildlife. As winter temperatures become warmer and there are fewer freeze events in the southeastern U.S., mangrove forests are expected to expand their range and replace salt marshes.
Scientists are beginning to unpack what this transition means for coastal wetland ecosystems. In a newly released publication in the Journal of Ecology, scientists from the University of Louisiana at Lafayette and the U.S. Geological Survey point out that changes from mangrove expansion will likely occur not only above ground, but also below. Mangrove forests tend to have more vegetation above ground than salt marshes, as well as (for some) more peat development in the soil. Such differences are relevant in the context of climate change because both above-ground vegetation and below-ground peat act as carbon sinks.
However, one key finding of the researchers is that there’s no one-size-fits-all model for what will happen when mangroves encroach. Instead, the types and extent of changes (especially below ground) are highly dependent on the existing characteristics of the site – for example, its salinity and annual rainfall. In particular, dry, high salinity locations may experience the biggest soil changes (more peat) in response to mangrove arrival. These results are important for helping natural resource managers predict and plan for how coastal wetland ecosystems will respond to climate change in the southeastern U.S.
These findings are part of a larger study investigating the ecological changes associated with mangrove expansion. The study is supported by the Department of Interior Southeast Climate Science Center, which is managed by the USGS National Climate Change and Wildlife Science Center. The center is one of eight that provides scientific information to help natural resource managers and communities respond effectively to climate change.
Photo: Mangrove forest in St. Mark's National Wildlife Refuge, Wakulla County, Florida. Credit: Alan Cressler
Published Date: July 22nd, 2018
There are many models, tools, experts, and maps available that provide decision support for local decision makers to address the potential impacts of rising sea-levels. However, different models are not always developed for the same purposes and it can be difficult to determine which model and resources are the best for a specific given need.
The Northern Gulf of Mexico Sentinel Site Cooperative and the Southeast Climate Science Center (SE CSC) have released a new resource to help resource managers make decisions about models - Keeping Pace: A short guide to navigating sea-level rise models! This quick four-pager covers the importance of sea-level rise model selection, helpful concepts, model categories, and an example of how to utilize these models to address coastal issues.
When many people think of drought, they consider its impacts on human food and water supplies. But the effects of drought can actually go much deeper and are often more insidious. Long periods without rainfall can alter the delicate balance of natural ecosystems and harm many fish and wildlife species. The term “ecological drought” encompasses and emphasizes these environmental consequences. The Science for Nature and People (SNAP) Ecological Drought Working Group defines ecological drought as “a prolonged and widespread deficit in naturally available water supplies — including changes in natural and managed hydrology — that create multiple stresses across ecosystems.”
In 2015, the Climate Science Centers (CSCs), National Climate Change and Wildlife Science Center (NCCWSC), and university partners undertook the challenge of understanding the regional effects of drought on wildlife and ecosystems, identifing potential threats to valued resources, and prioritizing research efforts that consider potential drought effects on ecological systems.
To support this initiative, NCCWSC is partnering with the University of Maryland’s Integration and Application Network (IAN) to hold a series of 8 workshops, one with each of the 8 CSC regions. These workshops are aimed at collating existing knowledge of the ecological impacts of and resistance and adaptation to drought across the U.S. The regional workshops will culminate in a national synthesis project where representatives from each CSC will collectively write and publish several papers describing the state of our knowledge on ecological drought.
Keep an eye out over the coming months for a new series of posts on our website. These will describe the outcomes of each of the 8 workshops, give an overview of ecological drought impacts across the country, and provide information on our ongoing drought-related research projects in the 8 CSC regions!
New research from NCCWSC-funded scientists at North Carolina State University and the University of Montana shows that the evolutionary clock is ticking for snowshoe hares, which may not be able to keep up with the seasonal shifts caused by climate change.
Snowshoe hares rely on camouflage for protection, changing their coats from brown in summer to white in winter. This only protects them, however, when snow cover comes and goes each year on the same schedule.
Based on an article published this week in Ecology Letters, changes in snow timing and duration due to climate change are deadly for snowshoe hares. White hares stand out like "light bulbs” against snowless backdrops, presenting an easy target for predators. The researchers collected data from radiocollared snowshoe hares in Montana and found that mismatched hares suffer a 7 percent drop in their weekly survival.
“This paper shows that the mismatch costs are severe enough to cause hare populations to steeply decline in the future unless they can adapt to the change,” says lead author Marketa Zimova.
While individual hares cannot modify their molt timing or behavior, different hares molt at different times, enabling natural selection to favor those with molt schedules better suited to new snow patterns. Evolutionary change is slow, however, so the researchers recommend management actions that promote adaptation.
This research was funded in part by the USGS National Climate Change and Wildlife Science Center. Lead author Marketa Zimova also received support from the Southeast Climate Science Center. Learn more about the team’s work here.
Photo: White snowshoe hare on a snowless background. Credit: L. Scott Mills Research Photo
(Video will be posted online one to two weeks after the presentation date.)
Loblolly pine is the most productive and valuable commercial forest species in the southeast U.S. and comprises 80% of the planted forestland in the southeast. Southeastern forests contain 1/3 of the contiguous U.S. forest carbon and form the backbone of an industry that supplies 16% of global industrial wood.
In addition to the sessions and presentations below, don't miss the AGU Honors Ceremony and Banquet on Wednesday, December 16 where two Southwest Climate Science Center Principal Investigators, Glen M. MacDonald and Jonathan T. Overpeck, will be recognized for their recent selection as 2015 AGU Fellows!
Communication as a Driver of Landscape Change (Poster Session: GC11D) Convener & Chair: Kristin Timm, Science Communications Lead, Scenarios Network for Alaska and Arctic Planning (SNAP) and the Alaska Climate Science Center* Monday, December 14, 2015: 8:00am - 12:20pm
NOTE: This list includes sessions and presentations where a CSC-affiliate is a primary convener or presenter. CSC staff, researchers and affiliates are involved, as co-authors and partners, on a number of other presentations at AGU. For a full list of programs and presentations at the meeting, please visit the AGU website: http://fallmeeting.agu.org/2015/.
Published Date: July 22nd, 2018
Researchers from North Carolina State University have found that urban environments increase pathogen abundance in honey bees (Apis mellifera) and reduce honey bee survival. The finding raises significant questions as urban areas continue to grow at the expense of rural environments, and urban beekeeping becomes more popular.
“We wanted to determine if the increased temperatures and impervious surface areas associated with urban environments have an effect on the number of pathogens bees are exposed to, and to the bees’ immune responses,” says Steve Frank, an associate professor of entomology at NC State and co-author of a paper on the work.
“We also wanted to look at both managed honey bee colonies and ‘wild’ ones, to see if that made a difference – and it did,” says David Tarpy, a professor of entomology at NC State and corresponding author on the paper.
Working with volunteers, the researchers identified 15 feral colonies, living in trees or buildings without human management, and 24 colonies managed by beekeepers in urban, suburban, and rural areas within an hour’s drive of Raleigh, N.C. The researchers collected worker bees from all of the colonies, and analyzed them to assess the bees’ immune responses and their overall “pathogen pressure.” Pathogen pressure accounts for both the types of pathogen species present and the abundance of those pathogens.
The research team found that colonies closer to urban areas and those managed by bee keepers had higher pathogen pressure.
“Overall, we found that the probability of worker [bee] survival in laboratory experiments declined three-fold in bees collected from urban environments, as compared to those collected in rural environments,” Frank says.
However, the researchers also found that immune response was not affected by urbanization.
“Since immune response is the same across environments, we think the higher pathogen pressure in urban areas is due to increased rates of transmission,” Tarpy says. “This might be because bee colonies have fewer feeding sites to choose from in urban areas, so they are interacting with more bees from other colonies. It may also be caused by higher temperatures in urban areas affecting pathogen viability or transmission somehow.”
“Feral bees expressed some immune genes at nearly twice the levels of managed bees following an immune challenge,” Frank says. The finding suggests that further study of feral bee colonies may give researchers insights that could improve honey bee management.
“Honey bees are important pollinators and play a significant role in our ecosystems and our economy,” Tarpy says. “This work is really only a starting point. Now that we know what’s happening, the next step is to begin work on understanding why it is happening and if the same negative effects of urbanization are hurting solitary, native bee species that are presumably more sensitive to their local environment.”
The paper, “Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees,” was published Nov. 4 in the journal PLOS ONE. The co-lead authors of the paper are Elsa Youngsteadt, an entomology research associate at NC State, and Holden Appler, a former graduate student at NC State. The paper was co-authored by Margarita López-Uribe, a postdoctoral researcher at NC State.
The work was supported by Agriculture and Food Research Initiative, the U.S. Department of Agriculture’s National Institute of Food and Agriculture; the North Carolina Department of Agriculture and Consumer Services; a Dean’s Enrichment Grant from the NC State College of Agriculture and Life Sciences; a gift from the North Carolina State Beekeepers Association; and by the Department of the Interior’s Southeast Climate Science Center (SE CSC).
Wetlands across the U.S. and around the world act as a crucial link between land and water, providing a number of services such as removing excess nutrients, pollutants, and sediment from water and acting as natural buffers to floodwaters. In 1991, the Environmental Protection Agency established May as American Wetlands Month to celebrate the importance of these ecosystems.
Understanding both the impact of climate change on wetlands and the role that wetlands play in adapting to climate change is a vital part of ensuring climate change preparedness. Several of the research projects funded by the Climate Science Centers (CSCs) focus on ways to improve the methods and tools used in wetland research and to help shed light on how changes in climate might affect these invaluable resources. The results of these studies are often used to support planning and decision-making by natural and cultural resource managers.
• In the Northwest, a group of researchers found that some wetland amphibians are at risk of local extinction due to climate change and the intentional introduction of predatory species, as described in a paper published last year. The team is integrating remote sensing, hydrological and biological modeling, and traditional fieldwork to understand climate change impacts to wetland habitats.
• In the Gulf of Mexico, a team is researching the connections between climate and wetland ecosystem structure. This study explores the effect of freshwater availability on plant species abundance, comparing scenarios of a drier vs. wetter future for the south central and south eastern U.S.
• Mangrove forests are also being studied in the Gulf of Mexico and Atlantic coast to understand how mangrove forest migration, due to changes in regional climate, can cause displacement of salt marshes. This change in coastal plant life has important implications for the ability of coastal ecosystems to handle climate change impacts such as sea-level rise and extreme storm events.
• Researchers in the Northeast have conducted a critical evaluation of terrestrial and wetland habitat classification and mapping methods to help standardize various ecosystem maps that currently exist and help managers utilize such maps when making decisions about wetland vulnerability or other problems.
• Studies are being conducted in the Pacific Northwest and in California where salt marshes, mudflats, and shallow bays act as connected habitats that support a wealth of wildlife species. Scientists are examining current weather patterns, bottom elevations, tidal range, and sediment of wetland habitats to see how these elements affect plants and animals, and to understand how they will be impacted by climate change.
These projects represent only a small portion of our work on understanding climate change impacts to wetlands and other important ecosystems throughout the U.S. To learn more about our research, please browse our project pages by region or visit our project search page.
Images on page: Top right: St. Marks NWR Wakulla County_FL (by Alan Cressler) Middle left: A Cascades frog peeks out of the water in Olympic National Park (by Maureen Ryan) Bottom right: Mangrove marsh (by Mike Osland)
(Video will be posted online one to two weeks after the presentation date.)
Sustainable management of natural resources under competing demands is challenging, particularly when facing novel and uncertain future climatic conditions. Meeting this challenge requires considering information about the effects of management, disturbance, land use and climate change on ecosystems. State-and-transition simulation models (STSMs) provide a flexible framework for integrating landscape processes and comparing alternative management scenarios, but incorporating climate change is an active area of research.