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Riparian Ecosystem Management Study (REMS)

  • What:  Compare the effects of three riparian buffer options on headwaters stream ecology.

  • How:  Compare basins, before and after logging (i.e., How did they change?).

  • Scope and Duration:  HCP lands; at least 6 years (see timeline (Excel)). 

  • Investigators:  Three agencies cooperate to meet study objectives.  Washington Department of Natural Resources, U.S. Department of Agriculture Forest Service, and Washington Department of Ecology.

  • Basin description:  Area 1.5 - 7.6 hectare (ha); elevation (confluence) 20-390m; channel length 94-403m

Introduction

Rules governing Forest Practices on industrial forest lands in Western Washington are often specific to lands category.  One such category is state trust lands (PDF), consisting of ~ 730,000 ha of forested lands within the range of the northern spotted owl. These lands are managed under a partnership known as the trust-lands Habitat Conservation Plan (HCP), intended to protect cultural resources, riparian areas, and endangered or uncommon species (DNR Final Habitat Conservation Plan, 1997) in compliance with the Endangered Species Act (1973).

Most state lands in Western Washington are managed under the trust lands HCP. Specific riparian buffering rules for Type 5 streams on these lands were deferred in 1997 to allow DNR time to devise rules to protect water quality, fish, and wildlife resources. The REMS is intended to guide this effort.

Objective and Purpose

This small-scale pilot study compares the biological and physical characteristics of a sample of headwaters basins before and after logging.  We are studying several things, including:

  • Range of water temperature before and after logging.
  • Response of biological populations to logging.
  • Changes to in-channel large wood loads due to logging.

The data helps guide development of long-term policy for headwaters basins on HCP lands.  Results are applicable to management at multiple scales:

  • Seasonal extremes.
  • Between-basin and between-year variation and trends.
  • Differences in treatments.
  • Platform for planning future work.

Publication

Characteristics of small headwater wetlands in second-growth forests of Washington, USA is a journal article. This article was published in the journal, Forest Ecology and Management, Volume 261(Issue 7), pages 1265-1274, April 1, 2011. Two authors of this article are employees of the Washington State Department of Ecology.

Considering a little-known topic, we examined headwater-associated wetlands as part of a larger study focused on effects of forest management in headwater riparian areas. Most of the 30 predominantly first-order streams studied (summer low flows typically < 0.3 L s-1) were hydrologically complex, consisting of a main surface channel connected to multiple, small wetlands. We considered frequency, surface area, and other attributes associated with these small, cryptic wetlands.

Results suggest small headwater wetlands could dominate headwater surface processes by doubling stream surface area, and that their occurrence favors northerly aspects. This could lead to unexpected results such as northerly-facing streams warming most after logging. The frequency of these features suggests (1) the potential to influence every headwaters stream, and (2) importance as refugia to amphibians, many species of which are now in decline in the Pacific Northwest. Additionally, we observed that these features appear highly sensitive to changes in hydrology and may thus ‘flicker’ at a time scale of several years.

With surface areas well below minimum survey-and-manage size criterion for forested wetlands in use in the Northwest, the small headwater wetlands we observed are not currently inventoried. However, small headwater streams are thought to account for roughly 80% of total stream length in the Northwest. Thus, a majority of wetlands in the Northwest may remain uncataloged.

If you have questions, contact William Ehingher, PhD. via email or call 360-407-6416.