WICOMICO'S FORESTS
Wicomico's forests improve public health, encourage recreation, and offer aesthetic pleasure while maintaining habitat for a diverse array of creatures. Sadly, climate warming will have critical effects on forested ecosystems, and are likely to exhibit greater impacts on those ecosystems that are already weakened due to human-induced stressors. Read on to find out how reducing the impacts of non-climate stresses can buffer forests from the additional, inevitable damages of climate change.
Wicomico's forests improve public health, encourage recreation, and offer aesthetic pleasure while maintaining habitat for a diverse array of creatures. Sadly, climate warming will have critical effects on forested ecosystems, and are likely to exhibit greater impacts on those ecosystems that are already weakened due to human-induced stressors. Read on to find out how reducing the impacts of non-climate stresses can buffer forests from the additional, inevitable damages of climate change.
Overview
Forests not only enhance the local economy through timber production, but also provide habitat for wildlife and cycle nutrients throughout the landscape. Forests clean the air and filter water, improving public health and supporting healthy seafood throughout the entire region. Public forests, including Pemberton Historical Park, Roaring Point Park, and the Chesapeake Forest Lands, allow adventurers to hike, hunt and picnic. They radiate aesthetic beauty and inspire individuality while simultaneously protecting important ecological communities. During the seventeenth century, hardwoods such as white and red oak, hickory, and black gum would have dominated the landscape of Wicomico County, but because of agricultural expansion, many of these older forests were cleared for farming. Today, much of the abandoned agricultural land has been recolonized by early successional forests whose dominant species include loblolly pines and hollies. Oaks, black gum, green ash, beech, dogwood, and cypress are also present [1].
Forests not only enhance the local economy through timber production, but also provide habitat for wildlife and cycle nutrients throughout the landscape. Forests clean the air and filter water, improving public health and supporting healthy seafood throughout the entire region. Public forests, including Pemberton Historical Park, Roaring Point Park, and the Chesapeake Forest Lands, allow adventurers to hike, hunt and picnic. They radiate aesthetic beauty and inspire individuality while simultaneously protecting important ecological communities. During the seventeenth century, hardwoods such as white and red oak, hickory, and black gum would have dominated the landscape of Wicomico County, but because of agricultural expansion, many of these older forests were cleared for farming. Today, much of the abandoned agricultural land has been recolonized by early successional forests whose dominant species include loblolly pines and hollies. Oaks, black gum, green ash, beech, dogwood, and cypress are also present [1].
According to the Spatial Analysis Lab Tree Management Assessment Team, 117,327 acres (49%) of Wicomico County were covered by tree canopy in 2011. The tree canopy represents the layer of leaves and branches that shade the ground when viewed aerially and is a good measure of forest cover in Wicomico County [2]. Today, most of Wicomico's forests are loblolly pine forests, largely due to commercial interests, but hardwood forests and mixed hardwood-pine forests are also popular. Hardwood swamp forests are much more rare and are declining rapidly as a result of saltwater intrusion from sea level rise. White oaks are among the most common hardwood species in the area, but prefer dry soils. Should climate change cause the sea level to spill into Wicomico's floodplain, many populations of this upland species may be doomed. Other species, such as the Bald Cypress and Atlantic White Cedar prefer wetter, swamp-like conditions. However, as freshwater becomes inundated with rising salt water, these salt-intolerable species must migrate or die [3].
To complicate things further, as sea level rises due to climate change, the land in Wicomico County is also sinking due to glacial retreat from the last ice age. Plus, a slowing Atlantic Gulf Stream no longer whisks water away from the Eastern US seaboard as strongly as it used to. See, the Gulf Stream is sloped, and the coastal side can be 3-5 feet lower than its eastern edge. When the gulf Stream flows faster, the slope is steeper, aided by the Earth's rotation. When its flow slows, the angle of the slope decreases, and the water level rises on the coastal side causing extreme flooding during high tides. Moreover, shifts in the North Atlantic Oscillation has altered atmospheric wind patterns and storm tracks, affecting the distribution of water along the Eastern Shore. Meanwhile, El Niño climate cycles can also alter wind patterns and raise sea level in certain years. Thus, sea level rise is occurring much faster here on the Eastern Shore than elsewhere. It is unclear whether slow growing, long-lived species will be able to migrate fast enough before they suffocate in the intruding saltwater. Therefore, as the freshwater lens is pushed farther upstream with the rising saltwater tides, the dynamics of forests will change [4].
For more information about why seas are rising faster on the US East Coast than the global average, visit Yale e360:
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How Climate Change Adds to Current Forest Stressors
Changes in climate patterns will have critical effects on forested ecosystems, but are likely to exhibit greater impacts on those ecosystems that are already weakened due to human-induced stressors. Surely, an intact ecosystem would be much more resilient to the added stress of climate change than an already-stressed ecosystem. According to NASA, the average global temperature has already increased by ~1.4 degrees Fahrenheit since 1980. Although it may not seem like much, a one-degree change in global temperature is indeed significant because it takes a great deal of energy to heat all the oceans, atmosphere, and land by that amount... and it is still warming. For reference, a one-to-two-degree drop was historically enough to plummet the Earth into the Little Ice Age, while a five-degree drop 20,000 years ago had concealed most of North America under a deep field of ice [5]. It is uncertain whether ecosystems will be able to adapt quickly enough to drastic climate warming, and even more uncertain whether global society will commit to large scale efforts to reduce greenhouse gas emissions. Meanwhile in Wicomico County, we may turn our focus to reducing the impacts of non-climate stresses on ecosystems so as to buffer them from the negative effects of climate change [6].
Find out how current, non-climatic forest ecosystem stressors become exacerbated with climate change in Wicomico County:
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FOREST FRAGMENTATION
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EMISSIONS
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NON-NATIVE SPECIES
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Ecosystem Stressor: Forest Fragmentation
Fragmentation causes the genetic diversity of populations to plummet by preventing the migration of species between fragments. Fragmentation also reduces the interior:edge ratio, which encourages the loss of larger, longer-lived species that need an expansive area of uninterrupted (interior) habitat. Instead, there are increases in the numbers of edge-species, which are weedy and non-native species adapted to disturbance [6]. |
CLIMATE CHANGE ON FRAGMENTATION: Fragmentation occurs when humans subdivide plots of forest into smaller, isolated areas. Forests in the Delmarva Peninsula are heavily fragmented, and in Wicomico County, this is largely due to agricultural activity, residential development, road construction, and the conversion of native hardwoods to pine plantations for timber management. Species respond to environmental changes either by adapting, shifting ranges, altering species abundances, or fleeing altogether. Species with short regeneration times are able to evolve quickly and consequently may be able to adapt to environmental changes by remaining in place or by simply migrating out of the area. Meanwhile, slower growing, long-lived species experience slower rates of adaption and may not be able to migrate as fast as the changing climate warrants. If the fragmented landscape impedes their movement, or if new habitats are not available for these species to migrate, Wicomico County may experience a decrease in species diversity as the climate warms. According to the IPCC, "the probability of ecosystem disruption and species extinction is positively related to the rate of climate change" (1998) because species shift their ranges at different rates, altering relationships between species that may be dependent on one another's existence [6].
CLIMATE CHANGE ON FRAGMENTATION: Fragmentation occurs when humans subdivide plots of forest into smaller, isolated areas. Forests in the Delmarva Peninsula are heavily fragmented, and in Wicomico County, this is largely due to agricultural activity, residential development, road construction, and the conversion of native hardwoods to pine plantations for timber management. Species respond to environmental changes either by adapting, shifting ranges, altering species abundances, or fleeing altogether. Species with short regeneration times are able to evolve quickly and consequently may be able to adapt to environmental changes by remaining in place or by simply migrating out of the area. Meanwhile, slower growing, long-lived species experience slower rates of adaption and may not be able to migrate as fast as the changing climate warrants. If the fragmented landscape impedes their movement, or if new habitats are not available for these species to migrate, Wicomico County may experience a decrease in species diversity as the climate warms. According to the IPCC, "the probability of ecosystem disruption and species extinction is positively related to the rate of climate change" (1998) because species shift their ranges at different rates, altering relationships between species that may be dependent on one another's existence [6].
Ecosystem Stressor: Emissions
Emissions such as Nitrogen and sulfur, from cars and power plants, result in ground level ozone and acid deposition that stress forest trees [6]. |
CLIMATE CHANGE ON EMISSIONS: Climate change is likely to exacerbate the consequences of fossil fuel emissions due to alterations of chemicals in the atmosphere. For instance, concentrations of hydrogen peroxide may increase in fog, rainwater, and surface waters because of the reaction between increased temperatures, nitrogen levels, hydrocarbons, and UV-B radiation. Hydrogen peroxide is toxic for land plants as well as for many aquatic creatures. Furthermore, fossil fuel combustion increases levels of carbon-dioxide in the air which then dissolves in rainwater to form carbonic acid, resulting in acid rain. As acidity and oxidants like hydrogen peroxide rise, forests will degrade and release nutrients into waterways leading to eutrophication and hypoxia in fresh and coastal waters [6].
Ecosystem Stressor: Invasion of Non-Native Species
Non-native species can be harmful to forests if they outcompete native species for resources. They have the ability to change the entire structure of the ecosystem. This photo features field workers as they walk through a nutria "eat-out" in a marsh along the Wicomico River on Maryland's Eastern Shore [6]. |
CLIMATE CHANGE AND THE INVASION OF NON-NATIVE SPECIES: Although it is possible that timber productivity could increase with the coming of warmer weather, this new forest growth is likely to reduce native biodiversity as some species will be unable to adapt to changing climates. While it is true that some species may become more abundant and widespread, these increases may not be beneficial if those that adapt most successfully to climate change are invasive species. This situation is extremely likely due to the characteristics of invasive species. In other words, invasive species tend to have resilient traits that allow them to easily colonize already existing communities. These traits include high reproductive rates and short turnover times, the ability to migrate long distances, tolerance of human disturbance, and tolerance of a wide range of abiotic conditions. Because the traits of invaders make them resilient to many types of disturbances, climate change is less likely to have detrimental effects on invaders than on fragile native species [6].
ConclusionFortunately, reversing the burden of non-climate stressors (such as forest fragmentation, emissions, and the invasion of non-native species) will provide a buffer against the impacts of climate change. We may take action within our own county by creating migration corridors to connect forest fragments, planting new forest, reducing our carbon emissions, and controlling the invasion of non-native species through adaptive management techniques. For example, all known populations of nutria, an invasive rodent from Asia, have been removed from over a quarter million acres of Delmarva due to management efforts from the Chesapeake Bay Nutria Eradication Project. As a result, the marshland which they used to feed upon is becoming reestablished in Wicomico County [7].
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"But I’ll tell you what hermits realize. If you go off into a far, far forest, and get very quiet, you’ll come to understand that you’re connected with everything.”
— Alan Watts
"But I’ll tell you what hermits realize. If you go off into a far, far forest, and get very quiet, you’ll come to understand that you’re connected with everything.”
— Alan Watts
Let's take a look at some species who call the Wicomico Forests home!
References
- Maryland Forest Service. Maryland Department of Natural Resources. (2007). Sustainable Forest Management Plan for Chesapeake Forest Lands: Sustainable Forests for People and the Bay (Report No. 11). Sustainable Forestry Initiative. Retrieved from http://dnr.maryland.gov/forests/Documents/chesapeake/CF-SFMP_2018.pdf
- O’Neil-Dunne, J. (2014). A Report on Wicomico County, Maryland’s Existing and Possible Tree Canopy. Retrieved from http://gis.w3.uvm.edu/utc/Reports/TreeCanopy_Report_WicomicoCountyMD.pdf
- Personal communication, Joe Fehrer, Coastal and Lower Shore Project Manager for The Nature Conservancy, 4 April 2018, Furnace Town Visitor Center.
- Morrison, J. (2018). Flooding Hot Spots: Why seas are rising faster on the U.S. East Coast. Yale School of Forestry & Environmental Studies: YaleEnvironment360. Retrieved from https://e360.yale.edu/features/flooding-hot-spots-why-seas-are-rising-faster-on-the-u.s.-east-coast
- Carlowicz, M. NASA. (n.d.) Global Temperatures. Retrieved from https://earthobservatory.nasa.gov/Features/WorldOfChange/decadaltemp.php
- Rogers, C. E., and McCarty, J. P. (2000). Climate change and ecosystems of the Mid-Atlantic region. Climate Research (14), 235-244. Retrieved from http://www.int-res.com/articles/cr/14/c014p235.pdf
- Maryland Department of Natural Resources. (2016). Maryland Mammals. Retrieved from http://dnr.maryland.gov/wildlife/Pages/plants_wildlife/Nutria.aspx