The Conservation of Sensitive Plants on Private Redwood Timberlands in Northern California1
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The Conservation of Sensitive Plants on Private Redwood Timberlands in Northern California1 Clare Golec,2 Tony LaBanca,3 and Gordon Leppig3 Abstract Redwood forests are not traditionally known for a diverse vascular plant flora or a large number of sensitive plant taxa. Approximately 90 percent of redwood forests are privately owned and most are managed for timber production. Historically, information on sensitive plants in the redwoods has been scarce because few sensitive plant surveys were conducted on public lands, botanists have typically not had access to private lands, and no botanical survey data was requested in the permitting process for projects on managed timberlands. Prior to 1999, most of the information available on sensitive plants in redwood forests was based upon early twentieth century herbarium specimens. In the late 1990s, state agencies began requesting sensitive plant survey data for projects conducted in managed redwood stands. Five years of plant surveys have resulted in an improved understanding of the ecology and distribution of many sensitive plant taxa. For taxa whose distribution and ecology have become better understood, landscape-level approaches to conservation are being developed. This paper presents an overview of the sensitive plant flora and management strategies used to conserve sensitive plants on privately-owned redwood forests. Key words: managed timberlands, redwood flora, sensitive plant conservation Introduction Redwood forests (Sequoia sempervirens) are the dominant forest type of the Northern California Coastal Forest Ecoregion. These forests are considered “globally outstanding” for their biological distinctiveness and have “critical” conservation status because intact habitat is restricted to isolated small fragments and land use of the remaining habitat is often incompatible with maintaining most native species and communities (Ricketts and others 1999). Less than five percent of all redwood stands are un-entered old-growth (Noss 2000) with the majority of the remaining 95 percent managed for short rotation commercial timber production. Humboldt and Del Norte counties, for instance, have over 648,000 acres (262,000 hectares) of commercial redwood timberlands, compared with 57,000 acres (23,000 hectares) of old-growth forest in federal and state parks (Fox 1989). California is famous for its floristic diversity and high percentage of endemic plants. Northwestern California, which includes the redwood region, is especially 1 This paper was presented at the Redwood Science Symposium: What does the future hold? March 15- 17, 2004, Rohnert Park, California. 2 Environmental Scientist/Botanist, California Department of Fish & Game, 1031 S. Main Street, Fort Bragg, CA 95437. email: [email protected] 3 Environmental Scientist/Botanist, California Department of Fish & Game, 619 Second Street, Eureka, CA 95501. email: [email protected] and [email protected] USDA Forest Service Gen. Tech. Rep. PSW-GTR-194. 2007. 169 Session 4—Conservation of Sensitive Plants—Golec, LaBanca, and Leppig renowned for its plant diversity and sensitive species (DellaSala and others 1999, Smith and Sawyer 1988). Yet despite the dominance and biological distinctiveness of redwood forests in the region, there is no landscape-level account of their sensitive plant flora. Historically, information on sensitive plants in redwood forests on commercial timberlands has been scarce because few floristic plant surveys were conducted and botanists have typically not had access. Prior to 1999, most of what little information there was on sensitive plants was based upon early Twentieth Century herbarium specimens and limited occurrence information in databases such as California Natural Diversity Database (CNDDB) and California Native Plant Society’s (CNPS) Inventory of Rare and Endangered Plants of California. No studies have assessed the abundance, diversity, ecology, and management impacts to sensitive plants in redwood timberlands. Stuart (1996) identifies one plant, Santa Cruz Cypress (Cupressus abramsiana) on a list of “threatened and endangered species found in redwood forests.” Sawyer and others (2000) presents a regional assessment of the rare plants of Mendocino, Humboldt, and Del Norte County redwood forests, however all habitats of the region are considered, including taxa restricted to coastal sand dunes and montane serpentine habitats. With so little information on sensitive plants in the redwoods, assessing status and distribution, analyzing potential threats from timber operations, and developing appropriate mitigation and conservation strategies is difficult. An understanding of the sensitive plants occurring in redwood timberlands is especially important given the large percentage of redwood stands in timber production and because timber operations can have significant adverse impacts on sensitive species. Schemske and others (1994) for instance, attributed logging as the primary cause of endangerment for over seven percent of plants listed as threatened or endangered by the U.S. Fish and Wildlife Service. Equally as important is information on life history and population demographics of sensitive taxa. Beginning in the late 1990s, the California Department of Forestry and Fire Protection (CDF) and the California Department of Fish and Game (DFG), in conjunction with other stakeholders, began evaluating the presence of, and impacts to, sensitive plants during the preparation of Timber Harvesting Plans (THPs). Under the THP preparation and review process, land managers began conducting surveys for sensitive plants in potential habitats, disclosing occurrences to CDF and DFG, and developing mitigation measures to avoid or minimize impacts to these occurrences. This survey, disclosure, and mitigation process was conducted pursuant to the California Forest Practice Rules, Fish and Game Code Title 14 California Code of Regulations, and the California Environmental Quality Act (CEQA). DFG has three key objectives for conserving sensitive plants (Morey and Ikeda 2001): • Maintenance of viable populations within vegetation and habitat types representing the range of conditions throughout which a species occurs. • Protection of habitat and populations. • Maintenance of genetic variability and integrity. For a number of species, when a sensitive plant population is found in a THP area, DFG and other stakeholders have been monitoring these populations for response to timber management activities. Many of these THP-based monitoring programs involve the collection of simple census data—counting the number of 170 USDA Forest Service Gen. Tech. Rep. PSW-GTR-194. 2007. Session 4—Conservation of Sensitive Plants—Golec, LaBanca, and Leppig plants in a site before operations and recounting the individuals at certain intervals after management activities. Other monitoring activities have a landscape-level focus that attempt to assess what the overall trend of a species is across an ownership or the region. The sensitive plant surveys conducted for THPs in the past five years have surveyed less than 10 percent of the study area, yet this effort has resulted in the discovery of hundreds of rare plant occurrences. Based upon survey, mitigation, and monitoring data developed by DFG and other stakeholders since 2000, there now exists a much greater understanding of the distribution and composition of the redwood sensitive plant flora. Method The study area is redwood forests in Del Norte (DNT), Humboldt (HUM), and Mendocino (MEN) counties (fig. 1). This area was chosen because the majority of commercial timber harvesting operations, as well as corresponding botanical survey effort, documented sensitive plant occurrences, and monitoring, are found within those counties. Within the study area, redwood forests are defined as described in the redwood series by Sawyer and Keeler-Wolf (1995). In addition, associated vegetation types found wholly within or commonly interfacing with redwood forest are also incorporated. This includes coastal prairie, coastal scrub, chaparral, oak and pine woodland, grasslands, wetlands, and mixed evergreen forest. We define sensitive plants as all vascular plants listed as endangered, threatened or rare4, or those meeting the definitions of rare or endangered provided in Section 15380 of the CEQA Guidelines. Taxonomic nomenclature follows Hickman (1993). The documented sensitive plants of redwood forests in Del Norte, Humboldt, and Mendocino counties (hereafter northern redwood forest) were determined by the following means: 1. Analysis of the sensitive plant occurrence data in CNDDB (CNDDB 2005) and the Inventory of Rare and Endangered Plants of California (CNPS 2005); 2. Review of location and habitat data from herbarium specimens at Humboldt State University (HSC), California Academy of Sciences (CAS), University of California, Berkeley (UC), and the Jepson Herbarium (JEPS); 3. Assessment of the habitat and location information provided in the literature and regional floras (Hickman 1993, Hitchcock and others 1955-1969, Mason 1957, Munz and Keck 1970, Smith and Wheeler 1992); and 4. Review of the unpublished data such as DFG sensitive plant consultations, sensitive plant survey reports, and reports from timberland owners. 4 Pursuant to Section 670.2, Title 14, California Code of Regulations; Section 1900, Fish and Game Code; Endangered Species Act, Section 17.11, Title 50, Code of Federal Regulations USDA Forest Service Gen. Tech. Rep. PSW-GTR-194. 2007. 171 Session 4—Conservation of Sensitive