Biological responses to stream nutrients: a synthesis of science from experimental forests and ranges

TitleBiological responses to stream nutrients: a synthesis of science from experimental forests and ranges
Publication TypeJournal Article
Year of Publication2021
AuthorsRyan, DF
JournalPNW-GTR-981. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 522 p.
Pagination1 - 522
Date Published2021///

This report reviews existing research and datasets from 17 U.S. Forest Service-affiliated experimental forests and ranges (EFRs) that are relevant to science needs of state and federal water quality regulatory agencies. A focus group of regulatory personnel chose “biological responses to stream nutrients” as the focus for this synthesis, and identified a broader array of science topics that could be of regulatory interest. Additional research needs of regulators that could potentially be filled by future studies at these sites were identified as (1) the composition of biotic communities and responses to nutrient enrichment in low-nutrient reference streams, (2) effects on streams of forest management practices, and (3) aquatic impacts of air pollution and of climate change. Monitoring of relatively undisturbed EFR reference watersheds provides data on baseline stream conditions useful for developing water quality criteria with the reference waterbody method. Studies at EFRs in eight ecoregions may provide a basis for nutrient stressor-response models, a second method for developing water quality criteria. Management experiments at EFRs have been used to formulate and test best management practices for forests. Hypothesis-testing research into ecological mechanisms underlying stream processes at EFRs can be used to develop models of stream responses.EFRs offer opportunities to expand research on classes of streams that are underrepresented in the regulatory science base, particularly headwater streams with detritus-based food webs and ephemeral and intermittent flows. Research networks containing multiple EFRs could be used to produce science needed to address large-scale regulatory issues that span multiple ecoregions. Cooperative research at EFRs involving water quality regulatory agencies and land management agencies could potentially produce mutual benefits.