Treesearch

Long-term flow records from sub-watersheds in the Caspar Creek Experimental Watersheds were used to test the accuracy of four methods commonly used to estimate peak flows in small forested watersheds: the Rational Method, the updated USGS Magnitude and Frequency Method, flow transference methods, and the NRCS curve number method. Comparison of measured and calculated results for 10-year return-interval flows demonstrates that, under the conditions tested, the direct flow transference method provides the most reliable results if suitable data are available; results for 100-year flows show...

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...

How quickly and in what way does a channel bed respond when large wood elements are introduced in a way that imitates natural wood loading processes (un-anchored or anchored by burial)? Using a design streamflow threshold for determining the size of key large wood elements, what changes in channel bed and habitat complexity occur after streamflow events above and below the threshold? These are questions we are currently trying to answer with a large wood habitat enhancement project on the East Branch of Soquel Creek within Soquel Demonstration State Forest in Santa Cruz County, California....

Stream temperature impacts have resulted in increased restrictions on land management, such as timber harvest and riparian restoration, creating considerable uncertainty for future planning and management of redwood (Sequoia sempervirens (D.Don) Endl.) forestlands. Challenges remain in the assessment of downstream cumulative stream temperature effects given the complexity of stream temperature dynamics. The goal of this research is to identify processes and measurements that can aid the assessment of risk of downstream temperature heating. Stream temperature, hydrologic, climatic, and...

The early day logging of coast redwood in Humboldt County was destructive, dramatic, and dangerous. Giant old-growth redwoods were felled by pairs of “choppers” using double-bitted axes and long crosscut saws. Felling a single tree could take a week. After bucking, logs were initially moved by water to mills on the shores of Humboldt Bay. Logging railroads gradually took over part or all of log transport. In extreme situations, movement of logs required use of inclined railways and trestles built directly over streams. As late as the 1970s, loggers were subjected to a mortality rate of...

What responsibilities do humans have to ensure that redwoods survive? And what values and strategies are required to accomplish such a purpose? A basic assumption is that the saving of a species, or more broadly of an ecosystem, is ultimately about human survival and that there is a responsibility to use all tools available to this end. To date, our actions to sustain redwoods include setting aside acreage in parks and reserves, sustainably harvesting redwoods for commercial use, and educating ourselves and the public on the benefits and services of the redwood forest. These are current...