Habitat Fragmentation (deforestation, corridors)

Habitat Fragmentation (deforestation, corridors)

Decision makers require unbiased information on the ecological consequences of the increasing fragmentation of native habitats and communities. Research is needed to determine the causal mechanisms underlying populations and ecosystem responses to habitat reduction. Natural resource managers require synthesized data, management options, and visualization tools to understand relationships between habitat quality and quantity and population viability. Studies are needed to quantify the role of scaling in understanding and forecasting the spatial and temporal responses of biological systems to habitat fragmentation. Models are needed that will enhance our ability to define spatial and functional habitat requirements. Knowledge must be developed and applied to sustain functional habitat units and wildlife corridors that will protect populations of key plants and animals. We need to improve methods and increase the use of genetics and molecular tools for understanding and maintaining populations, particularly how the size, shape, and location of “island” ecosystems and wildlife corridors may or may not function as reservoirs of genetic diversity.

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  Focus existing interdisciplinary teams to study habitat fragmentation of Appalachian hardwood forests, including development of more reliable indicators to characterize patterns of change
  
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  Encourage interdisciplinary working groups to enhance remote sensing techniques to quantify landscape attributes, and model and predict temporal and spatial changes
  
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  Summarize and synthesize knowledge of how urbanizing landscapes, including disturbance to native vegetation, geomorphology and soils, may impact community homeostasis and may encourage the establishment and spread of invasive and nuisance species
  

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  Integrate knowledge among hydrologists and biologists on factors that may limit mussel, fish, amphibian and avian populations among increasingly isolated and degraded river, wetland, and estuarine habitats
  
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  Enhanced collaborations between remote sensing and GIS technologists that will enable mangers to better visualize and quantify the changing landscape and improve land management decision-making
  
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  Conduct a workshop to develop the protocols for assessment of the ecological effects of dam removal
  
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  USGS scientists need to work with other Federal and academic investigators to incorporate social and economic information into long-term monitoring and adaptive management approaches
  

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  River and Coastal Processes
  

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  Sea-level rise (from melting glaciers)
  
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  Subsidence (ground water, oil and gas withdrawal, sediment starvation, compaction)
  
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  Slope failure / tsunamis - offshore (disassociation of gas hydrates)
  
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  Erosion & deposition (jetties, levees, groins, breakwaters, dredging, hardening)
  

• Sedimentation changes from rivers (increases or decreases)

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  Contamination (pathogens, trace elements, nutrients, human-made organics)
  
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  Landslides – off-shore (e.g. Puerto Rico)
  
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  Habitat alteration (natural and from resource extraction)
  

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  Channelization (keeping river within narrow bounds)
  
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  Increases or decreases in sedimentation rates
  
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  Runoff (usually markedly increased from impervious surfaces)
  
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  Dams (prevent anadromous fish from migrating, prevent sediment from moving further downstream changing channel characteristics)
  
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  River flow changes
  

• Water temperature increases (cutting trees and shrubs that would otherwise shade a stream, industrial cooling discharge)

• Habitat alteration

Perhaps the greatest challenge associated with coasts and rivers is the need to educate people that 1) coast lines and river beds are naturally dynamic - not fixed; they change, sometimes dramatically, as a result of natural processes, including storms, 2) by trying to protect a coast line or river, human intervention may actually make the situation worse, as natural processes may be disturbed, and 3) many species have adapted to changing coasts and rivers, so that human-induced changes may substantially impact indigenous species. Perhaps the greatest scientific need is to more fully understand the physical processes impacting coastal areas, including sediment erosion, transport, and deposition. Additional research is needed to make predictive models quantitative, not just qualitative, so that issues of vulnerability can be more completely and reliably described.