Ecology

A useful comparison starts with the ecological condition of the site before development. Species observations, vegetation communities, habitat connectivity, acreage, hydrology, aerial imagery, and surrounding land uses can establish that baseline. The ecologist can then examine whether construction, clearing, access roads, drainage changes, or other site alterations changed habitat availability, fragmented ecological connections, or affected particular species or communities.

Ecological risk assessment examines how a chemical, biological, or physical stressor could affect plants, animals, communities, habitats, or ecosystems. The analysis typically defines the ecological resources of concern, identifies stressors and exposure pathways, evaluates evidence of effects, and addresses uncertainty. EPA describes the process as applicable to stressors such as chemicals, land-use change, disease, and invasive species.

A biodiversity claim requires more than showing that different species were observed at two points in time. An ecologist may examine species richness and abundance, survey methods, habitat conditions, seasonality, sampling effort, disturbance history, and natural variability. The significance of a change depends on the ecological context, the reliability of the underlying data, and whether the observed pattern can reasonably be connected to the activity being disputed.