HomeMy WebLinkAboutEmail from Melanie Truan - Butte Creek Canyon Overlay Zone Menchaca, Clarissa
From: Melanie L Truan <rnitruan@ucdavis.edu>
Sent: Sunday,April 22, 2018 3:31 PM
To: Connelly, Bill
Cc: Clerk of the Board
Subject: Support for BCC Overlay
Dear Supervisor Connelly,
I am writing to express my support for the Butte Creek Canyon Conservation Overlay for its value in preserving
and protecting wildlife populations, migratory corridors, and the ecology of the Butte Creek canyon. Several
years ago, I participated in an interdisciplinary study sponsored by EPA/NCER that substantiated significant
interconnections between the creek's aquatic and terrestrial realms and the importance of maintaining access
to the Butte Creek canyon for wildlife.
Chinook salmon are a keystone species that link aquatic and terrestrial ecosystems, and support directly or
indirectly many ecosystem services in watersheds. Annual runs of Pacific salmon historically transferred large
quantities of marine-derived nutrients into the California interior through direct consumption and
decomposition of salmon carcasses, supporting forests, terrestrial animals, and other aquatic species (Merz
and Moyle 2006).
Our study confirmed that spring-run Chinook salmon were indeed transferring marine-derived nutrients,
primarily nitrogen,to the Butte Creek ecosystem and that these nutrients were being actively incorporated
into the food web through uptake by plants and animals in the riparian corridor.
Deployment of camera traps along the creek confirmed that many species were using the creek during the
spawning season, in particular black bear who likely traveled long distances to feed upon the salmon. Bears
are especially adept at transferring marine-derived nutrients from the aquatic to the terrestrial environment
by harvesting fish and bringing the carcasses onshore to feed. Other organisms consume what the bears leave
behind and plants and decomposers incorporate the nutrients into their tissues, thus enriching the entire
ecosystem. We know, for example, that bears with access to salmon in the fall enter hibernation in better
physical condition and produce more cubs (Hilderbrand et al. 1999). Similarly, access to salmon-fertilized
nutrient-rich plants during the fall and winter may be important for the survival and reproductive success of
the Tehama Deer Herd.
Maintaining bears' access to salmon streams is critical to the process of nutrient cycling across ecosystem
boundaries and is considered a "keystone interaction" for its widespread effects on ecosystem structure and
function (Helfield and Naiman 2006). Protecting wildlife corridors and limiting development in the canyon will
facilitate these interactions, since bears tend to avoid human-modified areas (Matsubayashi et al. 2014).
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Moreover, maintaining access to salmon runs for black bears and limiting development in the canyon may
serve to decrease human-bear conflicts in developed areas.
For a variety of reasons, and especially for the maintenance of habitat and migratory corridors for wildlife, I
support this Conservation Overlay. Limiting development in the Butte Creek canyon will help maintain its value
to both wildlife and people.
Thank you for the opportunity to comment on this matter.
Melanie L.Truan Ph.D
Research Ecologist
Museum of Wildlife&Fish Biology
Dept.of Wildlife,Fish&Conservation Biology
University of California,Davis
530/867-3610
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