Forest Investment Account (FIA) - Forest Science Program
FIA Project Y103080

    Carnation Creek - Forestry impacts and watershed recovery processes in a small coastal drainage
 
Project lead: Peter Tschaplinski (Ministry of Forests and Range)
Author: Bird, Steve A.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Description:
Carnation Creek is a long-term, multi-disciplinary case study of the effects of forestry practices on a small coastal watershed. Carnation Creek is a small stream, 7.8 km long, that drains an area of 11 km2. The study uses an intensive, pre-treatment vs. post-treatment-impact design that currently consists of five years of pre-harvest baseline data (1970/71-1975), six years of observations from 1976-1981 when 41% of the basin was harvested, and 27 years of post-harvest studies. Another 25% of the basin was harvested in headwater areas remote from the main stream channel in the 1990s. The study features both clearcut (Tributary H) and control (Tributary C) sub-basins. Riparian forestry treatments vary from intensive clearcutting to variable-width riparian buffers. The overall purpose of this study is to determine the mechanisms, rates, and levels of forestry-related impacts and recovery in a harvested coastal drainage by quantifying long-term changes in biological and physical watershed processes. We are currently determining the mid-term (25-30 years) post-harvest responses to logging practices from the condition and attributes of the hydrologic regime, second-growth forests, hillslopes, stream channel network, riparian forest canopy, aquatic habitats (mainstream and tributaries), water temperatures, and salmon populations. Fish population responses measured include long-term trends in abundance, growth, age structure, survival, and smolt production.
We integrate component studies of hillslope, stream channel, floodplain, and riparian processes to describe and model functional linkages and determine the ultimate consequences for channel morphology, aquatic habitats, and fish. Core data collected annually are provided to our research team and partners for applications that include the on-going development and refinement of basin-scale models for hydrology, landslide prediction, sediment and debris budgets, channel changes, and fish habitat capability. The information gained is relevant for validating current forest practices and supporting forest policy, regulatory, and guideline development that promotes the sustainable use of forest resources, and protects watershed processes and aquatic values. This study provides key validation-research support for the B.C. Forest and Range Effectiveness Evaluation Program (FREP), FRPA implementation, and for the MFRís Future Forest Ecosystems Initiative for climate change adaptation.
Key Research Questions: Our 38-year datasets provide the necessary framework required to directly address the following questions directly relevant to forestry and watershed management:
(1) What is the cumulative effect of harvesting beyond specific levels (i.e., 65% basin harvest)?
(2) What is the effect on channel morphology and aquatic (e.g., salmon) habitats in both larger streams and their smaller tributaries when the riparian vegetation is removed or modified?
(3) What biological changes result from these altered stream habitats?
(4) How long do these physical and biological changes persist?
The results of our research will be applied to address these long-standing issues around fish-forestry interactions and riparian and watershed management. As such, we expect to contribute information useful as reference materials for forestry professionals who are responsible for delivering desirable management outcomes pursuant to British Columbiaís resultís-based Forest and Range Practices Act.
Focus for 2009-2010: The key research question for 2009-2010 continues from 2007-2008 and the previous year. Within the current 3-year program, we have a unique opportunity to determine and directly quantify the ultimate effects of a massive pulse of sediment and debris on the entire mainstream channel and its anadromous salmon habitats and to measure resultant impacts on fish populations. Illustrating hillslope-channel connections, these materials originated from forestry-associated landslides and debris torrents that occurred more than 24 years ago in three steep headwater tributaries 1 km upstream of anadromous habitats. These materials have been slowly transported downstream to now alter morphology and habitats throughout the entire andromous salmon zone of Carnation Creek. Therefore, we are currently in a key phase of the project because for the first time since forest harvesting was implemented (1976), a substantial down-turn in the abundance of Pacific salmon directly attributable to forestry is being consistently observed. Previously, the relative effects of forestry practices on Carnation Creek salmon have been relatively small when compared to other sources of variation such as ocean conditions, climatic shifts, and fisheries management. While these other factors remain prominent, the contribution from forestry-related activities is increasing, and will likely continue to increase in the next several years. This change coincides with significant alterations to the main channel that will also impede fish access to key tributary rearing habitats. The delayed nature of the forestry-related impacts (23 years and more), and the predicted level of it, are significant matters for consideration for forestry professionals who will be implementing "results-based" harvest management decisions under FRPA. Our results will show that some forestry-caused alterations may take decades to emerge, and also emphasise the importance of sound forestry management in steep headwaters where streams are closely coupled to the adjacent hillslopes.
We seek funds to support the third year of a 3-year mid-term study of forestry-related impact and recovery. We use a 2-tiered research approach:
1. Core physical and biological data funded primarily by FIA-FSP. Annually, we collect, analyze, and summarize primary data on climate (six stations), hydrology (four weirs), stream channel morphology and fish habitat (standard ground-based and aerial-photo surveys), and fish populations. Main-channel and tributary fish fences are used to study salmonid migrations, while multi-pass (electrofishing and pole-seines), ground-based surveys are used to study rearing populations. These data are used to determine the annual status of the physical and biological attributes and processes in Carnation Creek.
2. Derivative studies funded mainly through in-kind support by our team members and partners. We supply the above-noted core data to support process studies and model development/refinement to describe and/or predict post-harvest alterations or recovery to the hydrologic regime, hillslopes, stream channels, aquatic habitats, and fish populations. Not all derivative studies are active each year (e.g., DOC/UV study and DOC/N component), but over the long-term, they include:
(a) rainfall interception and runoff;
(b) water quantity and quality of surface flows;
(c) landslide frequency and location;
(d) hillslope/channel sediment-and-debris budgets (sediment storage and transport models);
(e) in-channel sediment mobilization and channel condition;
(f) water temperature and its effect on salmonid growth and survival in fresh water;
(g) dissolved organic carbon (DOC) shielding of UV light vs. fish survival; and
(h) export of water, DOC, particulate organic carbon, and N to the ocean and effects on coastal marine alga blooms and juvenile salmon survival.
(i) long-term changes in forest vegetation (pre-logging to post-logging recovery)
This project is fully consistent with the 10-year SPAC Priority 1.6 Watershed Function, Priority (e). Our research provides basin-scale, integrated research that complements component-type studies on riparian management and area-harvest effects on headwater streams (Malcolm Knapp Research Forest: J. Richardson, D. Moore, others; Upper Penticton Creek: R. Winker, B. Heise, others), hillslope-channel interactions (Donna Creek: J. Schwab), modeling forestry-hydrology interactions (Cotton Creek & Baker Lake DHSVM peak flow and water yield: Y. Alila).
Related projects:  FSP_Y081080FSP_Y092080

    Deliverables:

Carnation Creek channel survey results, 2009 (6.8Mb)

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Updated August 16, 2010 

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