Biodiversity

Overview

We will be looking into how climate change impacts the biodiversity and species composition of Vermont. Human-caused climate change is altering the species composition of biological communities in many regions of the world. As climate patterns change, species are migrating as their niches expand. Through this expansion comes many impacts on native species as they are confronted with new competitors and less than ideal physical conditions. We will be investigating how these changes affect Vermont ecosystems and social implications through research and interviews in University of Vermont and the greater Burlington community.

-Nina Ferrari, Zach Walker

An Interview with Jeffrey Hughes

            Dr. Jeffrey Hughes, Associate Professor of Plant Biology and Natural Resources at the University of Vermont specializes in forest ecology, forest communities, and forest ecosystems.  During a recent interview, I asked Dr. Hughes about some of the effects that climate change has had and may have in the future on the species composition of terrestrial ecosystems in Vermont and New England. Dr. Hughes mentioned changes in the habitats of both animal and plant species that may be due to the increasing temperature or to changes in patterns of precipitation associated with climate change.  Since climate change is so gradual, Dr. Hughes notes that it is very difficult to pinpoint an exact moment when changes occur, but he has noticed patterns that may be associated with increasing temperatures over recent years. He also pointed out that because trees have a slower generation time than animals, we will probably notice changes plants and plant communities much later than we do changes in wildlife species and their communities.  

            Dr. Hughes, a native of Maine, has noticed changes in the plants and animals of New England over the last few decades.  He has witnessed a slow integration into Vermont's natural communities of some southerly plants and animals that previously were associated with warmer climates, for example turkey vultures, opossums and cardinals.  In turn, there is concern that these species may be more competitive for resources than some native Vermont species, or that the new arrivals may be increasing predation pressures on native Vermont prey species.  Dr. Hughes also referred to how warming climates also may have affected the life histories of pest species in New England, particularly arthropod pests. For example, a majority of arthropod pest larvae dies off during the winter months due to low temperatures.  However, warmer temperatures affect tick pests in two ways, first is fewer tick larvae die over the winter so that in the following spring the pest population is much more robust after the larvae molt to adults; and second is adult tick pests are able to remain active much later in the fall and begin their activity much earlier in the spring when the climate is warmer. For example, in New Hampshire moose tick larvae have been surviving the recent warmer winters in much larger numbers.  In some winters, the moose tick adults are able to infest moose throughout the year.  Since moose are exposed to ticks throughout the whole winter, they are much more likely to succumb to tick-borne blood disease. As a result New Hampshire has seen positive correlation of temperature with tick populations, and a decrease in moose populations.

        Increasing temperatures affect not only populations, but whole communities. A clear example that Dr. Hughes has seen relates to changes in the transition zone on mountains in Vermont which may affect the biodiversity of plants in Vermont. The transition zone occurs on the slope of a mountain where the dominant plant species begin to change from deciduous species found lower on the mountain side to coniferous trees found toward the peak. Dr. Hughes has noticed that deciduous tree species that commonly grow at the lower part of the transition zone now are growing at higher elevations.  This suggests that as the climate is warming, the elevation of the transition zone is being displaced further up the mountain face.  As a result, the area above the transition zone, where conifers prefer to grow, is becoming more restricted.  Eventually, we may find no conifers on the mountaintops of Vermont, only deciduous trees throughout the mountain.  In addition, Dr. Hughes predicts that we are likely to see more southerly species such as oaks and hickories become more abundant in Vermont forests, and displace native species like sugar maple and hemlock that prefer a cooler climate.

These effects of climate change not only affect directly the native species of Vermont, they also can have indirect social implications, both positive and negative, on the Vermont community. With decreasing moose populations in New England, some states have been tightening up their hunting laws to restrict moose hunting. This, in turn, decreases revenue for the state and negatively impacts the state economy.  Moose hunting in New England states like New Hampshire and Vermont brings in a lot of money directly to the state government from the sale of licenses to hunt these animals.  Moose hunting also affects the state's economy indirectly by increasing hotel occupancy and restaurant income during hunting season. The declining moose populations due to tick-borne diseases brought about by climate change that favors tick populations may have severe impacts on the revenue of the state.  Another example of a negative affect is the Vermonters pride - maple syrup.  As climate change results in increasing temperature, there is a risk that the Vermont area eventually may become a less than ideal for sugar maples, and we may see declines in quantity and quality of our famous maple syrup. Another tourist industry that may be adversely impacted by warming temperatures is decreasing revenue from leaf peepers. Vermont is known throughout the world for its beautiful forest colors, and people throughout the U.S. visit Vermont particularly in the early fall to enjoy the spectacle.  However, as Dr. Hughes mentioned, with the change in plant species composition of our forests due to northward dispersal of more southerly species, as well as the fact that trees in general produce less bright leaves in warmer weather, Vermont may suffer a decrease in hotel and restaurant revenue from the tourist attraction associated with the leaf peeping season.

However, there may be some benefits to terrestrial biodiversity from gradual warming. With warmer weather Vermont’s climate may become more suitable to grow a wider variety of food year round, strengthening the locavore movement so that Vermonters can more easily enjoy locally grown food through a greater part of the year.  Other benefits are more difficult to predict but they may surprise us.  However, there can be no doubt that global warming will continue to bring about climate change, resulting in changes to the biodiversity and species composition of the Vermont landscape.  As Dr. Hughes points out, some of these changes may be subtle, like the shifting transition zone on a Vermont mountain.  Others will be more overt and impact the state economy. It seems best to begin to address climate change now before the consequences become more severe.

-Nina Ferrari

Pests and Moose Populations – New York Times

In my interview with Dr. Hughes he mentioned how pests, like ticks, are affecting wildlife populations in the northeast. That reminded me of a New York Times article I read recently by Jim Robbins published in October 2013. In Moose Die-Off Alarms Scientists Robbins explained how a shorter, warmer winter is increasing the number of ticks feeding on Moose which is leading to a decrease in moose populations in New Hampshire, British Columbia, Montana, and Minnesota. Robbins also describes how this has a social and economic affect on the communities.

Take a look!
http://www.nytimes.com/2013/10/15/science/earth/something-is-killing-off-the-moose.html?smid=pl-share

Robbins, J. (2013, October 14). Moose Die-Off Alarms Scientists. The New York Times.

-Nina Ferrari

Projected Shift in Forest Type

Graphic courtesy of US Global Change Research Program on EPA webpage
http://www.epa.gov/climatechange/impacts-adaptation/forests.html 

This map represents the projected shift in tree species composition and forest types in the eastern U.S. over the next 100 years and compares it with the species composition from the last 50 years. If you look at Vermont, you can see exactly what Dr. Hughes mentioned in his interview. There is an expected decrease in what was the dominating forests type of Maple-Beech-Birch. The current forest type is likely to be replaced by hardwood species like Oaks and Hickories that are currently found in more southern states. This changes is primarily due to warming. Warmer conditions will create less ideal conditions for our current forest type in Vermont as well as in other parts of the country.

-Nina Ferrari

VT Fish and Wildlife Conservation in Response to Climate Change

In March, 2012, John Austin, a member of the Vermont Agency of Natural Resources and the Vermont Fish and Wildlife Department published a report in the Climate Change Adaption White Paper Series about the adaptations Vermont species have to make because of climate change. Austin identified the main threats to native Vermont species as warmer and shorter winters, water related changes (including increase in precipitation and snowmelt), and change in the timing of seasonal events. These threats can result in species migration, changes in species composition/distribution, species outcompeting one another, and the introduction of new species. At this point it is impossible to curtail climate change; so the VT Fish and Wildlife Department is pairing with other conservation organizations, land trusts, and private landowners to take preventative action to combat some of these changes. Some of their efforts include the conservation of land, construction of habitats, habitat management, and control of species development in order to conserve the natural communities of Vermont.

If you want to know more here is a link to the full report!
http://www.anr.state.vt.us/anr/climatechange/Pubs/VTCCAdaptFishandWildlife.pdf

Austin, J. (2012, March). Climate Change Adaptation White Paper Series: Fish and Wildlife

     Conservation and Climate Change Adaptation in Vermont. Vermont Agency of Natural Resources.

-Nina Ferrari

Climate Change Affecting Sugar Maples - New York Times

Similarly to the moose in New Hampshire, warmer winters are affecting Vermont species as well, specifically sugar maple trees (Acer saccharum). This, in turn, is hindering the maple syrup industry. In the New York Times article Warm Winters Upset Rhythms of Maple Sugar, Belluck explains how Vermont’s maple syrup may be at risk. The cold winter temperatures set the sugar maple’s biological clock. In the winter the cooler temperatures replenish the sap, and in the spring the warmer temperatures crates pressure causing sap to flow out of the tree. Typically the maple-tapping season begins in March, as soon as the winter temperatures rise above freezing, but in recent years it has started in mid February. Maple syrup producers, like Burr Morse in Montpelier, are suffering because the shorter season is effecting their syrup production and profit. Eventually the season will become too short for them to break even. This article also refers to what Dr. Hughes mentioned in my interview, that decades from now there may be fewer maples in Vermont as they are displaced by oaks and hickories. We may live to know a Vermont without maple syrup.

Here’s a link to the article, check it out!

http://www.nytimes.com/2007/03/03/us/03maple.html?pagewanted=all&_r=0

Belluck, P. (2007, March 3). Warm Winters Upset Rhythms of Maple Sugar. The New York Times.

-Nina Ferrari

About the Authors

Nina Ferrari
 I am sophomore at the University of Vermont. I am in the Rubenstein School of the Environment and Natural Resources majoring in Wildlife Biology. I grew up along the Potomac River in McLean, VA a suburb of Washington D.C. As a Wildlife Biology major I am able to explore my interests through an academic perspective in a classroom as well as hands-on outdoor learning. After graduating I plan to go to graduate school to specialize in conservation biology.

Works Cited

Austin, J. (2012, March). Climate Change Adaptation White Paper Series: Fish and Wildlife

     Conservation and Climate Change Adaptation in Vermont. Vermont Agency of Natural Resources.


Belluck, P. (2007, March 3). Warm Winters Upset Rhythms of Maple Sugar. The New York Times.


  Robbins, J. (2013, October 14). Moose Die-Off Alarms Scientists. The New York Times.