Threats to Forest Ecosystem Health Activities together influence ecosystem structure & function introduced species poor management air pollution global warming habitat fragmentation American Chestnut From dominant forest tree species to legend 1
Chestnut Blight An introduced species takes its toll in the deciduous forest The American chestnut once comprised 25% of the eastern deciduous forest. The blight was introduced from Asia in 1904, and it essentially eliminated the species by 1950. A lethal strain of the blight fungus was inoculated into this American chestnut stem. The sunken canker is typical for a blight-susceptible American chestnut. http://ipm.ppws.vt.edu/griffin/blight.html Functional Parts of a Tree 2
Biodiversity - The Strength of the Forest Biodiverse ecosystem six species even representation Limited system one dominant species uneven representation Biodiversity - The Strength of the Forest Biodiverse ecosystem six species even representation system function is resilient Limited system one dominant species uneven representation ecosystem function is sensitive to stress 3
Ozone Damage and Tulip poplar 4, 5 Interveinal stippling or speckling on upper surface of leaves Ozone enters plant leaves during gas exchange Interferes with the ability of plants to produce and store food More susceptible to disease, insects, other pollutants, and harsh weather Precipitation ph in the United States 4
Acid Deposition Potential impacts on forests Precipitation contains elevated H +, SO 4 2-, and NO 3 - altered ion movements precipitation 1 2 4, 5 3 impacts: 1 - cation leaching from foliage 4 - aluminum toxicity to roots 2 - changes in soil chemistry 5 - N suppression of mycorrhizae 3 - leaching from soil to streams Nitrate Concentration in Precipitation in the United States 5
The Nitrogen Cycle Connections in the global biosphere 100 20 140 130 110 1200 N fluxes x 10 12 g N yr -1 6000 biogeochemical cycles bridge ecosystem compartments changes in inputs will change fluxes & pool sizes anthropogenic sources: fossil fuel combustion, stockyards, and fertilizers 36 30 Human alterations of the Nitrogen cycle have: Doubled the rate of N input into terrestrial N cycle Increased global concentrations of N 2 a greenhouse gas Loss of soil nutrients (Ca 2+, PO 2-4 ) Increased rates of N transfer to aquatic systems Increased quantity of organic C stored in terrestrial ecosystems Accelerated losses of biodiversity (mostly N-efficient species) Altered functioning of estuarine and nearshore ecosystems Contributed to long-term decline in coastal marine fisheries 6
Virgin Forests in West Virginia 1880 1930 following the Civil War, railroads accessed WV s resources it took only 50 years to denude West Virginia s mountains Forest Resources Turn-of-the-century logging removed most mature timber 7
Major Public Lands in West Virginia Account for approximately 15% of the area large portions of the eastern deciduous forest are privately owned the forest resource will be utilized based on economic parameters integrated management decisions cannot be formulated Los Angeles, CA Urbanization Morgantown, WV Changes water and sediment fluxes. Natural habitats are reduced and fragmented Exotic organisms introduced Energy flow modified Nutrient cycles modified 8
Coal Mining Changes in geological processes contaminate land & water runoff to surface waters overburden coal seams pyrite surface waters contaminated with AMD leaching to groundwater mine spoil interactions between water, substrates, and air produce AMD AMD alters chemical reactions in residual soils aluminum, iron, and manganese (toxic metals) are mobilized acids & metals impact terrestrial and aquatic life 9
Mountaintop Removal The next generation of coal extraction in the mountains Mountaintop Removal Valley Fill mountaintop overburden is removed and placed into valleys terrain is changed in process the area is seeded (often to grass) after coal removal is complete Global Surface Temperatures atmospheric change influences climate The Hadley Center for Climate Prediction & Research http://www.meto.govt.uk/sec5/cr_div/tempertr/index.html 10
Global Change Will influence abiotic resources & habitat range American beech current range overlapping range future range Based on predicted doubling of atmospheric CO 2 between 1990 and 2050 species ranges depend upon suitable habitat global warming will alter resource structure within habitats as resources change, regional shifts in species will occur 11