Prosper Ridge Prarie Restoration Phase 7 Map, May 2020. Map by Hugh McGee

By Hugh McGee, Program Director,
Mattole Restoration Council

Over the past several years Mattole Restoration Council (MRC) has been working with the Mattole Salmon Group, the Bureau of Land Management (BLM), various federal and state agencies, and local contractors to implement multiple phases of two important ecosystem restoration projects in the King Range National Conservation Area: The Prosper Ridge Prairie Restoration Project and the Lower Mattole Riparian and Estuary Habitat Enhancement Project. This summer we continue implementation of these projects and begin to align project tasks to fit the goals of both projects.

Prosper Ridge Prairie Restoration Project

Since 2014, the MRC has been working with BLM and local contractors to restore historic coastal prairies and create a landscape-level fuel break on Prosper Ridge, located just south and up the hill from the Mattole River estuary. A glance at the 1874 Coastal Survey Map and 1942–1993 air photos shows that these areas were once home to vast coastal prairie habitats. Since then, suppression of natural and human-created fires has resulted in the encroachment of dense stands of coyote brush and Douglas-fir. This change in vegetation led to the rapid decrease of important native grassland plant and animal communities, a decrease in soil-driven carbon sequestration, and increases in fire-prone vegetation, as well as loss of ecosystem processes that are important to soil health. In Phases 1–6 we removed more than 300 acres of encroaching Douglas-fir and coyote brush and installed over 100,000 native grass plugs and 1,000 lbs. of native flower and grass seed in place of the removed vegetation. This summer we began Phase 7, which includes the removal of an additional 40 acres of encroached vegetation and installation of 30,000 native grass plugs and over 1,000 lbs. of flower and grass seed. Long-term maintenance of these restored prairies will begin this winter, with over 200 acres scheduled for broadcast burning. With funding through the North Coast Resource Partnership, we will also have the opportunity to organize seven years of planning, methodology, and implementation data with production of the North Coast Grasslands Restoration Manual, co-authored by BLM and MRC staff. This manual is meant to assist restoration practitioners in planning and implementing grassland and oak woodlands restoration projects.

Mattole Riparian and Estuary Habitat Enhancement Project

Mattole River Estuary Restoration Project Map, April 2020. Map by Hugh McGee

Since 2013 MRC has been working with Mattole Salmon Group (MSG), BLM, CA Department of Fish & Wildlife, U.S. Fish & Wildlife Service, California State Coastal Conservancy, California Department of Water Resources, and local contractors to restore riparian and in-stream salmonid habitat in the lower two miles of the Mattole River. Prior to the 1964 flood events that resulted in heavy sedimentation of the lower Mattole River, this area consisted of abundant deep water and off-channel habitat for juvenile and adult salmonids and steelhead, as well as complex floodplain and riparian habitat. In recent decades the estuary area has lacked deep pools, cover, and off-channel habitat that provide thermal refugia for juvenile salmonids. Floodplains and terraces are riparian deserts with unsuitable conditions for germination of long-lived riparian trees and shrubs. To improve these conditions, MRC and MSG have implemented various habitat restoration projects over the years, including the installation of over 20,000 feet of willow baffles, restoration of 800 feet of the historic Middle Slough, installation of more than 400 whole trees, and planting of 20,000 native shrubs, trees, and wetland plants. This summer we continue our work in the lower river with the restoration of another 800 feet of the Middle Slough, installation of over a mile of willow baffles and willow and wood structures, and re-vegetation of project sites with seeding of native flowers, sedges, and grasses. We will also be installing 4000 wetland plugs and 4000 riparian trees.

Linking the Projects Together Utilizing Byproducts from Grasslands Restoration and Salmonid Habitat Restoration Efforts

Grasslands restoration and salmonid habitat restoration projects have two recurring questions during the planning phase: What are we going to do with all the biomass we remove from our grasslands restoration sites? and Where are we going to get the wood for our in-stream restoration projects? In 2014 and 2016 MSG used a helicopter to install 400 whole trees into the Mattole estuary and its floodplains. These trees were removed from privately owned grasslands adjacent to the Mattole estuary. MRC and MSG are currently working on a project in the Middle Mattole that utilizes the same concept of taking trees off a fuel break/encroached grassland and using them for in-stream salmonid habitat in Four Mile and Sholes Creeks.

With the implementation of Phase 7 underway, we again face the challenge of how to deal with large amounts of biomass produced from our grasslands restoration work. We typically create large burn piles (40’ in diameter and 15–20’’ high) that need to cure for a year before being burned. Down in the estuary we again face the logistical challenge and cost of trucking trees to floodplain and in-stream restoration project sites. This year we are fortunate to have funding to deal with these two issues and are contracting Columbia Helicopters to fly 200 whole trees from grasslands restoration areas on Prosper Ridge and help install them at floodplain and in-stream restoration sites in the Mattole River estuary. Some of these trees will be used to create whole-tree/willow structures on floodplains to increase riparian habitat and in-stream complexity during high flows. Others will be flown and installed on the Middle Slough Restoration Project to increase cover for juvenile salmonids in the newly restored off-channel habitat.

For more information:
www.mattole.org

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