Copyright © National Academy of Sciences. All rights reserved.
This executive summary plus thousands more available at http://www.nap.edu
Assessing and Managing the Ecological Impacts of Paved Roads
http://books.nap.edu/catalog/11535.html
Summary
9
known in advance, and in that case, some ecological effects of roads may
go undetected if an inappropriate scale is chosen. Few studies have addressed the complex nature of the ecological effects of roads, and the
studies that have done so were often based on small sampling periods
and insufficient sampling of the range of variability in ecological systems.
Recommendation: Research on the ecological effects of roads
should be multiscale and designed with reference to ecological conditions and appropriate levels of organization (such as genetics, species
and populations, communities, and ecological systems.)
Recommendation: Additional research is needed on the long-term
and large-scale ecological effects of roads (such as watersheds, ecoregions, and species’ ranges). Research should focus on increasing the
understanding of cross-scale interactions.
Recommendation: More opportunities should be created to integrate research on road ecology into long-term ecological studies by using long-term ecological research sites and considering the need for new
ones.
Recommendation: Ecological assessments for transportation projects should be conducted at different time scales to address impacts on
key ecological system processes and structures. A broader set of robust
ecological indicators should be developed to evaluate long-term and
broad-scale changes in ecological conditions.
CONCLUSION: The assessment of the cumulative impacts of
road construction and use is seldom adequate. Although many laws,
regulations, and policies require some consideration of ecological effects
of transportation activities, such as road construction, the legal structure
leaves substantial gaps in the requirements. Impacts on certain resources
are typically authorized through permits. Permitting programs usually
consider only direct impacts of road construction and use on a protected
resource, even though indirect or cumulative effects can be substantial
(for example, effects on food web components). The incremental effects
of many impacts over time could be significant to such resources as wetlands or wildlife.
Recommendation: More attention should be devoted to predicting, planning, monitoring, and assessing the cumulative impacts of
This executive summary plus thousands more available at http://www.nap.edu
Assessing and Managing the Ecological Impacts of Paved Roads
http://books.nap.edu/catalog/11535.html
Summary
9
known in advance, and in that case, some ecological effects of roads may
go undetected if an inappropriate scale is chosen. Few studies have addressed the complex nature of the ecological effects of roads, and the
studies that have done so were often based on small sampling periods
and insufficient sampling of the range of variability in ecological systems.
Recommendation: Research on the ecological effects of roads
should be multiscale and designed with reference to ecological conditions and appropriate levels of organization (such as genetics, species
and populations, communities, and ecological systems.)
Recommendation: Additional research is needed on the long-term
and large-scale ecological effects of roads (such as watersheds, ecoregions, and species’ ranges). Research should focus on increasing the
understanding of cross-scale interactions.
Recommendation: More opportunities should be created to integrate research on road ecology into long-term ecological studies by using long-term ecological research sites and considering the need for new
ones.
Recommendation: Ecological assessments for transportation projects should be conducted at different time scales to address impacts on
key ecological system processes and structures. A broader set of robust
ecological indicators should be developed to evaluate long-term and
broad-scale changes in ecological conditions.
CONCLUSION: The assessment of the cumulative impacts of
road construction and use is seldom adequate. Although many laws,
regulations, and policies require some consideration of ecological effects
of transportation activities, such as road construction, the legal structure
leaves substantial gaps in the requirements. Impacts on certain resources
are typically authorized through permits. Permitting programs usually
consider only direct impacts of road construction and use on a protected
resource, even though indirect or cumulative effects can be substantial
(for example, effects on food web components). The incremental effects
of many impacts over time could be significant to such resources as wetlands or wildlife.
Recommendation: More attention should be devoted to predicting, planning, monitoring, and assessing the cumulative impacts of