Treesearch

Interest in the restoration of second-growth forests has continued to increase in the redwood region, which has further increased the importance of evaluating restoration-based silvicultural strategies. This study assessed the short-term effectiveness of four silvicultural treatments (two silvicultural thinning methods, low thinning and crown thinning, and two basal area retentions, 80 percent and 45 percent) as forest restoration tools via analysis of relative basal area growth at Redwood National Park. Prior to treatment, the second-growth stand had more than 1,600 trees ha-1 and 70.0 m2...

The ongoing, severe drought in the redwood ecosystem has many ramifications, including loss of summer rearing habitat for juvenile salmonids. Many ‘perennial’ streams now cease to flow during parts of the summer and fall, either drying up completely or disconnecting pools as riffles go dry, subjecting fish to increased predation, high water temperatures, and desiccation. Numerous factors have contributed to this hydrologic impairment, including natural hydrologic cycles, legacy land use effects, human consumptive uses, and climate change. The search for solutions is now in full swing, and...

After decades of intensive timber harvest and land use change that removed forests from the landscape, recent satellite data show that forest cover has increased in North America (Liu et al. 2015). However, these regenerating forests differ greatly in structure and composition than the forests that preceded them (McIntyre et al. 2015). This has been especially evident on the Pacific coast, where only 3 to 5 percent of old-growth coast redwood (Sequoia sempervirens (D. Don) Endl.) forest remains (Russell 2009). To address this, land managers are actively thinning second-growth forests to...

Shallow streamside landslides are a principle source of sediment on managed timberlands in northern California. Using an adaptive management process, LiDAR, and a detailed field-based landslide inventory, Green Diamond Resource Company (GDRCo) has redefined the interim preventative landslide tree-retention buffers it applies to steep streamside slopes along fish bearing (Class I) and non-fish bearing (Class II) watercourses. The application of these buffers are dependent on slope gradients and when applied, enhance and in some cases, expand upon the customary riparian buffers associated...

A number of watersheds on the North Coast of California have been designated as sediment impaired under the Clean Water Act, including the 112 km2 upper Elk River watershed that flows into Humboldt Bay just south of Eureka. The objectives of this paper are to: 1) briefly explain the geomorphic context and anthropogenic uses of the Elk River watershed; 2) develop a process-based sediment budget for the upper watershed, including an explicit assessment of the uncertainties in each component; and 3) use the results to help guide future management and restoration. Natural (background) sediment...

The 1,295 ha (3,200 ac) Swanton Pacific Ranch (Swanton) and the associated Valencia Tract in Santa Cruz County have been managed by California Polytechnic State University, San Luis Obispo (Cal Poly) since 1987. Swanton’s Valencia Tract is a 239 ha (591 ac) property located north of Watsonville, California. Cal Poly forest managers have conducted two harvest entries since acquiring ownership of the Valencia tract utilizing a modified BDq individual tree selection approach. A 10-year continuous forest re-inventory (CFI) was completed for the Valencia coast redwood tract to update and...

Almost half of Redwood National Park is comprised of second-growth forests characterized by high stand density, deficient redwood composition, and low understory biodiversity. Typical structure of young redwood stands impedes the recovery of old-growth conditions, such as dominance of redwood (Sequoia sempervirens (D. Don) Endl.), distinct canopy layers and diverse understory vegetation. Young forests are commonly comprised of dense, even-aged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and redwood stump sprouts, with simple canopy structure and little understory development....

Disturbance is fundamental to forest ecosystem function, but climate change will continue to increase both disturbance frequency and intensity in the future. Forests subject to increasingly frequent and intense disturbances are more likely to experience overlapping (compounding) disturbance effects. Compounding disturbances may exert unpredicted, non-additive stresses on ecosystems, leading to novel conditions that may exceed the capacity for local species to survive and regenerate. We further hypothesize that compounding disturbances could alter physical and chemical growing conditions in...

It has been hypothesized that individuals adapted to conditions near the species’ range edge, may increase the likelihood that the species will persevere under changing climatic conditions (Rehm et al. 2015). The southern coast redwood (Sequoia sempervirens (D. Don) Endl.) forests vary from more northern redwood forests in terms of stand size, genetics, forest associates, and have less annual precipitation (Noss 2000). Redwoods regenerate through both seed and basal sprouting, with sprouting being the dominate regeneration method (Douhovnikoff et al. 2004). A study of three recent fires in...

The objective of this study is to test the effectiveness of California Forest Practice Rules and additional best management practices implemented as part of Humboldt Redwood Company’s Habitat Conservation Plan and Watershed Analysis prescriptions, in limiting the delivery of management-derived sediment. A paired watershed study format is being utilized to evaluate sediment sources: road surfaces, watercourse crossings, landslides, channel incision and bank erosion, and tributary channel head-cutting. The study compares the West Branch (1.48 km2, 365 ac) and the East Branch (1.28 km2, 314...