Integrating stream bioassessment and landscape ecology as a tool for land use planning

Abstract

1. Bioassessment has evolved significantly from a method of deciding whether an ecosystem exposed to stressors should 'pass' or 'fail' (or how badly it fails). Society wants some notion of what has caused any observed degradation of ecosystems, and what management strategies might improve degraded ecosystems. Managers also want to predict what negative or positive effects different land use strategies will have on the component ecosystems of a landscape, including lakes and streams. 2. Here we illustrate an approach to providing these tools to managers with data from a bioassessment study of streams in the Fraser River Basin of British Columbia, Canada. 3. Landscape scale descriptors of both the natural (e.g. catchment size, surficial geology) and stressor (e.g. hard rock mines, forest harvest) environment of each site were used to define the natural and stressor environments of each of the 242 stream sites. 4. We classified 206 reference (relatively unexposed to human activity) sites using their benthic macroinvertebrate community composition, and then discriminated among the faunally defined groups with landscape scale descriptors of the natural environment of the sites. 5. This discriminant function model allowed us to predict which group each of the test sites would be in if it were in reference condition, and then measure the relationship between the amount of human activity and the biota in each of these groups. 6. These relationships were turned into projections of what will happen to a stream ecosystem's biota if the stressor environment is either improved or degraded. These projection models form the basis of evidence-based land use planning that takes into account the health of freshwater ecosystems.

Use of the BEAST model for biomonitoring water quality in a neotropical basin

“…We and others Bonada et al, 2006, Bailey et al, 2007 have shown that predictive models and other biological metrics offer countless advantages for evaluating water quality. In the das Velhas River basin, we support the use of benthic assemblages in ecological models for understanding, evaluating, and mapping the environmental condition of hydrographic basins.…”

“…Globally, modern tools have been used in biomonitoring programs since the 1970s (Bonada et al, 2006, Bailey et al, 2007. Biomonitoring programs typically compare the ecological conditions of assemblages from test sites against those from reference sites with minimal alterations (Statzner et al, 2001;Bailey et al, 2005).…”

Status assessment and causal factors diagnosis of river system health

“…Ideally, the factors chosen should assist in the diagnosis of the probable cause of health degradation and inform management actions (Dole´dec et al, 2006;Bailey et al, 2007). A river system is usually affected by natural and human causes.…”

A Stochastic Dynamic Methodology (StDM) for reservoir's water quality management: Validation of a multi-scale approach in a south European basin (Douro, Portugal)

“…The analysis stopped when all the remaining variables had a significant level P < 0.05 (Zar, 1996). The multi-level approach gives realism to the interactions considered by incorporating into the model a typical ''cascade effect'' observed in these processes Bailey et al, 2007). Therefore, in order to simplify the model structure, only the main key-components were introduced as representative ecological indicators, but which obviously could be complemented by other relevant state variables or other dynamic variables in further applications.…”

“…Any environmental assessment must begin with a conceptual model that includes the natural geographic and habitat setting, human activity that can potentially stress the ecosystem (e.g., agriculture), stressors resulting from that human activity (e.g., increased nutrients) and the effects of those stressors on the ecosystem (Stevenson et al, 2004). Nowadays environmental assessment is pushed to assist with land use planning decisions and projections of 'what if' scenarios at the landscape scale and, consequently, it is necessary to capture the main cause-effect relationships between human activity and ecosystem responses (Bailey et al, 2007).…”