Patrick Jantz

Historical and Projected Climates as a Basis for Climate Change Exposure and Adaptation Potential across the Appalachian Landscape Conservation Cooperative

Global temperatures have risen over the last few decades, and even the most conservative climate models project these trends to continue over the next eighty-five years (IPCC 2013). As climate changes, flora and fauna will be forced to adapt or migrate (Aitken et al. 2008). Many species have been able to adapt to past changes in climate, moving south during glacial periods and north during interglacial periods. However, anthropogenic climate change in most areas is occurring much faster than previous climatic shifts. Flora, in particular, may be unable to adapt or disperse quickly enough to track suitable climate conditions (Corlett and Westcott 2013). Understanding historical and projected future trends in temperature, precipitation, and other climate variables is important for evaluating the current context and likely consequences of climate changes in national parks, and in developing effective strategies for climate adaptation.

Potential Impacts of Climate and Land Use Change on Ecosystem Processes in the Great Northern and Appalachian Landscape Conservation Cooperatives

Ecosystem processes are the physical, chemical, and biological actions or events that link organisms and their environment. These processes include water and nutrient cycling, plant growth and decomposition, and regulation of community dynamics (Millennium Ecosystem Assessment 2003). The ecological characteristics of many parks and protected areas are dependent on the ecosystem functions that result from interactions between ecosystem processes, characteristics, and structures. Ecosystem functions, such as the regulation of water flows, soil retention and formation, and the provisioning of habitat and maintenance of biological diversity, in turn, provide the foundation for the ecosystem services supported by parks and protected areas (Hansen and DeFries 2007). As such, the preservation of ecosystem processes can be an important conservation target that complements conservation goals for species and habitats. Defining these targets is the first step in the Climate-Smart Conservation framework (Glick, Stein, and Edelson 2011; Stein et al. 2014).

Vulnerability of Tree Species to Climate Change in the Appalachian Landscape Conservation Cooperative

Forests of the Appalachian Landscape Conservation Cooperative provide critical ecological and management functions. The moist climate of the eastern United States fosters productive stands that store relatively high amounts of carbon; for example, the Appalachian Landscape Conservation Cooperative (Appalachian LCC) accounts for only 7.6 percent of the contiguous United States but contains 18.8 percent of its aboveground forest biomass (derived from Kellndorfer et al. 2012). The Appalachian Mountains create substantial topographic and microclimatic diversity, and forests in the southern Appalachian LCC have some of the highest levels of endemic mammal, bird, amphibian, reptile, freshwater fish, and tree species biodiversity in the conterminous United States (Jenkins et al. 2015). Forest types vary from commercial pine plantations in the south to temperate hardwoods in the central Appalachians to high-elevation spruce-fir forests in the north.

Potential Impacts of Climate Change on Vegetation for National Parks in the Eastern United States

Forests in the eastern United States have a long history of change related to climate and land use. Eighteen thousand years ago, temperatures were considerably lower and glaciers covered much of the area where deciduous forests currently grow. As glaciers retreated and temperatures rose, tree species advanced from southern areas (Delcourt and Delcourt 1988) and may also have dispersed from low-density populations near the edge of the Laurentide ice sheet (McLachlan, Clark, and Manos 2005). A variety of other processes have also influenced the distribution of tree species. Derechos, tornadoes, and fires cause frequent, small- to intermediate-scale disturbances that are important influences on canopy structure and species composition, while larger disturbances, such as hurricanes, cause less frequent but more extensive changes (Dale et al. 2001).

Human and natural controls of the variation in aboveground tree biomass in African dry tropical forests

Understanding the anthropogenic and natural controls that affect the patterns, distribution, and dynamics of terrestrial carbon is crucial to meeting climate change mitigation objectives. We assessed the human and natural controls over aboveground tree biomass density in African dry tropical forests, using Zambias first nationwide forest inventory. We identified predictors that best explain the variation in biomass density, contrasted anthropogenic and natural sites at different spatial scales, and compared sites with different stand structure characteristics and species composition. In addition, we evaluated the effects of different management and conservation practices on biomass density. Variation in biomass density was mostly determined by biotic processes, linked with both species richness and dominance (evenness), and to a lesser extent, by land use, environmental controls, and spatial structure. Biomass density was negatively associated with tree species evenness and positively associated with species richness for both natural and human-modified sites. Human influence variables (including distance to roads, distance to town, fire occurrence, and the population on site) did not explain substantial variation in biomass density in comparison to biodiversity variables. The relationship of human activities to biomass density in managed sites appears to be mediated by effects on species diversity and stand structure characteristics, with lower values in human-modified sites for all metrics tested. Small contrasts in carbon density between human-modified and natural forest sites signal the potential to maintain carbon in the landscape inside but also outside forestlands in this region. Biodiversity is positively related to biomass density in both human and natural sites, demonstrating potential synergies between biodiversity conservation and climate change mitigation. This is the first evidence of positive outcomes of protected areas and participatory forest management on carbon storage at national scale in Zambia. This research shows that understanding controls over biomass density can provide policy relevant inputs for carbon management and on ecological processes affecting carbon storage.