Friday, August 7, 2009

PS 86-112: Changes in redwood forest health from 1996 to 2006

Christine A. West, Humboldt State University, John D. Stuart, Humboldt State University, and Steven R. Martin, Humboldt State University.

Background/Question/Methods

Although there are many studies relating to general forest health indicators, relatively little research has been conducted on forest health in coast redwood ecosystems.  A cross-sectional survey of landowners and professionals was carried out in 1996 to solicit opinions on the status of selected redwood (Sequoia sempervirens) forest health indicators.  The survey was repeated in 2006 to gauge changes in the condition of these forest health indicators over a ten-year period.  Six hundred and ninety eight redwood forest health surveys were mailed in September 2006 to forest landowners and professionals.  Two hundred and sixty valid surveys were returned by June 2007 representing 72% of the California redwood range (0.64 million hectares).

Results/Conclusions

Based on our survey we found four main trends:  1. Fire hazard had the highest ratings across nearly all respondent subcategories in both 1996 and 2006. The level of concern for this hazard increased from slightly low in 1996 to slightly high in 2006.  2. Sudden oak death was rated second to fire in importance, with the greatest concern in the Sonoma-Napa-Marin range of redwood, on public lands, and on parcels over 2023 hectares.  3. Alien plant invasion ratings remained the same or decreased in most subcategories with the largest decrease in old-growth habitats and in Sonoma-Napa-Marin counties.  4. Mammal, insect, and disease hazards were rated very low to moderately low by nearly all respondents consistent with 1996 results.  Survey respondents were well-aligned with the scientific community regarding the state of redwood forest health indicators.  This study illustrates the utility of how survey methods can provide managers and others with a viable tool to assess the condition of the redwood ecosystem and to target restoration and conservation efforts accordingly.