Natural Resources Management and Environmental Sciences

First Record of Serropalpus substriatus Haldeman, 1848 (Coleoptera: Melandryidae) on giant sequoia, Sequoiadendron giganteum (Lindl.) J. Buchholz (Cupressaceae): New larval host

Kim S. Camilli et al. — Thu, 07 Feb 2013 15:16:46 PST

Implementing Uneven-Aged Redwood Management at Cal Poly's School Forest, an Update

Douglas D. Piirto et al. — Thu, 07 Feb 2013 15:16:44 PST

California Polytechnic State University's School Ranch and Forest, called Swanton Pacific Ranch, is located just north of Santa Cruz, California and encompasses approximately 3,800 acres of crop, range, and forested areas. Coast redwood (Sequoia sempervirens [D. Don] Endl.), Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) and tanoak (Lithocarpus densiflorus [Hook. & Arn.] Rehd.) occur on approciximately 1,900 acres of the Swanton Pacific Ranch and at Valencia. Because of its high stumpage value, coast redwood is the preferred management species. In addition to economic reality, California Forest Practice laws severely limit the extent of stand manipulation that can occur on any one harvest entry in Santa Cruz County. In our opinion, the only suitable silvicultural system given these currently limiting circumstances is uneven-aged forest management. However, implementing uneven-aged forest management in coast redwood stands involves a number of choices on residual stand density, preferred tree species composition, maximum tree size, q-factor, stand structure, inventory design, tolerable residual stand damage, logging systems, logging costs, reforestation strategies, extent and size of group selection cuts, growth rates, monitoring criteria, ecosystem management, and much more. Single tree and group selection cutting methods have been applied in seven stands encompassing approximately 175 acres of the Scott Creek Watershed, habitat for the now threatened Coho salmon. Cable and tractor logging systems were used. the issues, choices, decisions and operational considerations of implementing uneven-aged coast redwood management in Santa Cruz County will be discussed in the context of needed research to support stand and forest level decision making.

Advice for the Secretary of Agriculture about Management of the Giant Sequoia National Monument

J. N. Clarke et al. — Thu, 07 Feb 2013 15:16:43 PST

Landscapes held in public trust are difficult to manage; a living National Monument subject to increased public use presents additional challenges. These landscapes are subject to regional and global effects outside the manager's control, such as global climate change and air pollution. They are also subject to innumerable local variables, most of whose effects are difficult to predict. The giant sequoia groves and their surrounding ecosystem are fiercely loved by many; although the goals may be broadly similar, the objectives and policies of these giant sequoia lovers are often sharply at odds.

Basidiomycete Fungi Reported on Living or Dead Giant Sequoia or Coast Redwood

Douglas D. Piirto et al. — Thu, 07 Feb 2013 15:16:39 PST

Causes of Uprooting and Breakage of Specimen Giant Sequoia Trees

Douglas D. Piirto et al. — Thu, 07 Feb 2013 15:16:37 PST

A study of the causes of uprooting and stem failure in old-growth giant sequoia (Sequoia gigantea [Lindl.] Decne) indicated many factors, depending upon the type of failure (by root, stem, or earth). Advanced decay and fire scars were the most frequently associated with failure. In 21 of 33 study trees, one-third or more of the roots were judged too decayed to provide support. Twenty-seven study trees possessed basal fire scars, and 26 fell toward the scarred side. Nine Basidiomycetes, including Fomes annosus, Poria albipellucida, Poria incrassata, and Armillaria mellea, were associated with decayed wood. Carpenter ants were found in or adjacent to the failure zone of nearly half of the study trees. Physical disturbances (e.g., roads, trails, streams) were associated with 22 tree failures, but their role in initiating requires further investigating.

Comparative Properties of Old- and Young-Growth Giant Sequoia of Potential Significance to Wood Utilization

Douglas D. Piirto et al. — Thu, 07 Feb 2013 15:16:36 PST

A comparative study and a literature review were made on various wood properties (e.g. anatomical characteristics, mechanical properties, specific gravity, content and properties of extractives and decay resistance) of old- and young-growth giant sequoia. Various causes for variability in decay resistance were examined.

Critical Evaluation of the Pulsed-Current Resistance Meter for Detection of Decay in Wood

Douglas D. Piirto et al. — Thu, 07 Feb 2013 15:16:34 PST

An evaluation of a pulsed-current resistance meter ("Shigometer®", Model No. 7950) for facilitating detection of decay was performed on wood blocks of giant sequoia heartwood and of white fir sapwood. As decay progressed over a 12-week incubation period, a trend of lower meter readings was obtained, confirming reported field measurements of other workers. Variability in meter readings in situations where the range in resistance readings between sound and decayed wood is narrow (e.g., giant sequoia heartwood) and apparent inability of the meter to make readings necessary to diagnose decay at MCs common to wood in service without ground or water contact are considered to be the major limitations of the instrument. Shortcomings of the instrument, along with suggestions for improvement in meter design, are discussed.

Uncertainty in hydrologic modelling for estimating hydrologic response due to climate change (Santiam River, Oregon)

Christopher G. Surfleet et al. — Thu, 07 Feb 2013 15:16:32 PST

This paper explores the predicted hydrologic responses associated with the compounded error of cascading global circulation model (GCM) uncertainty through hydrologic model uncertainty due to climate change. A coupled groundwater and surface water flow model (GSFLOW) was used within the differential evolution adaptive metropolis (DREAM) uncertainty approach and combined with eight GCMs to investigate uncertainties in hydrologic predictions for three subbasins of varying hydrogeology within the Santiam River basin in Oregon, USA. Predictions of future hydrology in the Santiam River include increases in runoff in the fall and winter months and decreases in runoff for the spring and summer months. One-year peak flows were predicted to increase whereas 100-year peak flows were predicted to slightly decrease. The predicted 10-year 7-day low flow decreased in two subbasins with little groundwater influences but increased in another subbasin with substantial groundwater influences. Uncertainty in GCMs represented the majority of uncertainty in the analysis, accounting for an average deviation from the median of 66%. The uncertainty associated with use of GSFLOW produced only an 8% increase in the overall uncertainty of predicted responses compared to GCM uncertainty. This analysis demonstrates the value and limitations of cascading uncertainty from GCM use through uncertainty in the hydrologic model, offers insight into the interpretation and use of uncertainty estimates in water resources analysis, and illustrates the need for a fully nonstationary approach with respect to calibrating hydrologic models and transferring parameters across basins and time for climate change analyses.

Variability in effect of climate change on rain-on-snow peak flow events in a temperate climate

Christopher G. Surfleet et al. — Thu, 07 Feb 2013 15:16:31 PST

The frequency of rain-on-snow (ROS) hydrologic events, which produce high runoff volumes and lead to large-scale flooding and avalanching, are likely to change in the future as the types and timing of precipitation change. The relationship between ROS precipitation events and peak daily flow events P1-year return were examined for historical and future runoff affected by climate change within the Santiam River Basin, Oregon. Historical streamflow records and modeled historical and future streamflow projections were analyzed for three sites across three elevation zones defined by the dominant precipitation types; rain, rain and snow transition, and snow. The results illustrate that, across elevation zones, historical peak daily flows P1-year return have a high frequency (>60%) of association with ROS. The historical association between peak daily flows and ROS is highest within the transient rain and snow elevation band (350–1100 m), with 80% and 100% of P1 and P5-year return peak flows associated with ROS, respectively. In a future with increased air temperature due to climate change, our results indicate that a decrease in the frequency of high peak flow ROS events will occur in the low and middle elevation zones while the frequency of ROS associated peak flows will increase in high elevation areas. The transition of winter precipitation from snow to rain is predicted to increase peak daily flows

Peak Flow Responses to Forest Practices in the Western Cascades of Oregon, USA

R. L. Beschta et al. — Fri, 16 Nov 2012 08:33:30 PST

The effects of clearcut silviculture (road building, clearfelling, cable logging, and site preparation) were evaluated using long-term peakflow records for three small watersheds (60–101 ha) and six large basins (62–640 km²) in the western Cascades of Oregon, USA. After a calibration period, two of the small watersheds were treated while the third remained untreated (control). Analysis indicated that peakflow increases following treatments were dependent upon peakflow magnitude. Peakflow increases averaged approximately 13–16% after treatment for 1-yr recurrence interval events, and 6–9% for 5-yr recurrence interval events. For the six large basins, multiple linear regression analyses of peakflows relative to: (1) peakflow magnitude; and (2) difference in percent area harvested provided mixed results. While significant (pr²) due to harvesting was generally small (1–7%).

An Approach to Study the Effect of Harvest and Wildfire on Watershed Hydrology and Sediment Yield in a Coast Redwood Forest

Christopher G. Surfleet et al. — Tue, 13 Nov 2012 11:02:55 PST

The Little Creek watershed, within California State Polytechnic University’s Swanton Pacific Ranch, is the location of a paired and nested watershed study to investigate the watershed effects of coast redwood forest management. Streamflow, suspended sediment, and stream turbidity have been collected during storms at two locations on the North Fork Little Creek and at the outlet of South Fork Little Creek from 2002 until present. In 2008, the watershed area between the two monitoring stations on the North Fork Little Creek watershed was harvested with an individual tree selection silvicultural system within the Santa Cruz County Rules of the California Forest Practice Rules. The South Fork Little Creek was left unharvested to serve as a control. In 2009, the Little Creek watershed was burned by a wildfire. The wildfire eliminated our control watersheds for the proposed Before After Control Intervention (BACI) study design. We present an alternative approach at detecting harvest and fire effects that uses rainfall/runoff models, soil erosion models, and sediment runoff relations to simulate runoff and sediment yield from the watersheds. The models and sediment runoff relationships will be developed within the framework of an uncertainty assessment to simulate pre-harvest and pre-fire conditions for the North and South Forks of Little Creek. The modeled results will be used as the control for the study which had been eliminated due to the wildfire in 2009. We use the HBV hydrologic model and sediment runoff relations to demonstrate our approach. An example of post-harvest and post-fire runoff and sediment changes within the uncertainty of the approach are demonstrated.

Watershed Analysis Results for Mendocino Redwood Company Lands in Coastal Mendocino and Sonoma Counties

Christopher G. Surfleet — Tue, 13 Nov 2012 11:02:52 PST

To assess the needs for conservation, restoration and condition of aquatic habitat within its land Mendocino Redwood Company (MRC) has been conducting watershed analysis. From watershed analysis completed to date, we estimate 73percent of the total sediment inputs over the last 30 to 40 years are road and skid trail associated. Of that percentage 30 percent is road and skid trail associated mass wasting, and 32 percent is road surface and point source erosion, the remaining 11percent is surface and point source erosion from skid trails. Hillslope mass wasting (not associated with roads or skid trails) represents 27 percent of the sediment inputs. Using controllable erosion as an indicator of future sediment yield, MRC estimates there is 2.2 million cubic yards of potential road sediment delivery to be controlled.

Watershed analysis has provided insights into aquatic habitat functions within coastal Mendocino and Sonoma Counties. The following qualitative indices by percent of streams demonstrate the quality of habitat functions: “on target” indicates habitat conditions that meet published targets for well functioning conditions, “marginal” indicates functional habitat conditions but not at optimal levels, and “deficient” indicates low habitat functions with need for improvement. Instream large woody debris (LWD) condition is mainly marginal and deficient with few streams being on target: one percent on target, 35 percent marginal, 35 percent deficient, and 29 percent no data. Stream shade conditions are mainly on target to marginal with some streams being deficient: 29 percent on target, 35 percent marginal, 12 percent deficient, and 24 percent no data. Stream temperature conditions for salmonids are found to be: 58 percent on target, 18 percent marginal, and 24 percent deficient. Salmonid spawning habitats are predominantly on target and marginal (15 percent on target, 35 percent marginal, three percent deficient, 48 percent no data). Salmonid rearing and over-wintering habitats are mainly marginal and deficient, with few on target streams (rearing habitat: one percent on target, 39 percent marginal, 13 percent deficient, 48 percent no data; over-wintering: two percent on target, 37 percent marginal, 13 percent deficient, 48 percent no data).

Generally speaking low LWD levels and high sediment inputs affecting rearing and overwintering habitat for salmonids are the primary issues that need improvement, to a lesser extent stream temperature and spawning habitat. MRC has developed policies for improvement of riparian conditions for long term LWD recruitment needs of stream habitat. In the short term MRC is promoting the restoration of LWD in streams to improve current conditions. Sediment inputs are dominated by road issues. MRC has committed to upgrading and modernizing its entire road network, a process that will take approximately 30 years. To date MRC has made substantial headway in addressing road erosion and aquatic habitat impacts. In the five years that MRC has owned this land; MRC has removed 11 salmonid migration barriers, decommissioned approximately 10 miles of streamside logging roads, and controlled at least 400,000 cubic yards of controllable erosion. Further, a comprehensive monitoring program will test whether the MRC policies and restoration efforts are improving aquatic habitat and resource conditions.

Selection of Hydrologic Modeling Approaches for Climate Change Assessment: A Comparison of Model Scale and Structures

Christopher G. Surfleet et al. — Tue, 13 Nov 2012 11:02:48 PST

A wide variety of approaches to hydrologic (rainfall–runoff) modeling of river basins confounds our ability to select, develop, and interpret models, particularly in the evaluation of prediction uncertainty associated with climate change assessment. To inform the model selection process, we characterized and compared three structurally-distinct approaches and spatial scales of parameterization to modeling catchment hydrology: a large-scale approach (using the VIC model; 671,000 km² area), a basin-scale approach (using the PRMS model; 29,700 km² area), and a site-specific approach (the GSFLOW model; 4700 km² area) forced by the same future climate estimates. For each approach, we present measures of fit to historic observations and predictions of future response, as well as estimates of model parameter uncertainty, when available. While the site-specific approach generally had the best fit to historic measurements, the performance of the model approaches varied. The site-specific approach generated the best fit at unregulated sites, the large scale approach performed best just downstream of flood control projects, and model performance varied at the farthest downstream sites where streamflow regulation is mitigated to some extent by unregulated tributaries and water diversions. These results illustrate how selection of a modeling approach and interpretation of climate change projections require (a) appropriate parameterization of the models for climate and hydrologic processes governing runoff generation in the area under study, (b) understanding and justifying the assumptions and limitations of the model, and (c) estimates of uncertainty associated with the modeling approach.

Road Runoff and Sediment Sampling for Determining Road Sediment Yield at the Watershed Scale

Christopher G. Surfleet et al. — Tue, 13 Nov 2012 11:02:45 PST

In this study, we demonstrate that watershed-scale estimates of road sediment production are improved if field measurements of road runoff and sediment production are used in the analysis. We used several techniques to spatially extrapolate measurements of road runoff and sampled sediment: comprehensive road runoff measurements, runoff estimates derived from the Distributed Hydrology Soil Vegetation Model (DHSVM), and adjustment of the road erosion models WARSEM and SEDMODL2.The sediment yield for the Oak Creek, Oregon, road network based on measured road runoff and sediment was 6.5 tons/year. When DHSVM was used to simulate road runoff, the estimated sediment from roads was similar, 6.9 tons/years. The road sediment production estimated by SEDMODL2 and WARSEM, adjusted with field-measured road runoff and sediment, was 28% and 34% less, respectively, than using the models with the default parameters. When applied to a road network in commercial forest land with frequent road use, the sediment yield estimated by SEDMODL2 and WARSEM without adjustment from field measurements was 480% and 610% higher, respectively, than with adjustments. We found that measuring runoff and sediment from one large storm event (≥1 year recurrence) provided a statistically significant relationship with the annual sediment yield.

Uncertainty Assessment of Forest Road Modeling with the Distributed Hydrology Soil Vegetation Model (DHSVM)

Christopher G. Surfleet et al. — Tue, 13 Nov 2012 11:02:42 PST

We used a generalized likelihood uncertainty estimation procedure with the Distributed Hydrology Soil Vegetation Model (DHSVM) for two streamflow and 11 road ditchflow locations. We observed considerable uncertainty in DHSVM simulations of forest road and stream runoff. The accuracy of simulations decreased as the size of the area modeled decreased. For streamflow, 44% of attempted model structures exceeded a 0.5 Nash–Sutcliffe efficiency threshold for a 630 ha catchment; 12% of attempted model structures exceeded a 0.5 Nash–Sutcliffe efficiency threshold for a 55 ha catchment. DHSVM simulations produced behavioral model structures for only six of the 11 road ditchflow sites (<10 >ha). Cumulative distribution functions of parameter values did not indicate specific parameter ranges of parameter values across all locations, indicating that parameter values in DHSVM are influenced by their interaction with other parameters. The sensitivity of parameters and the range of that sensitivity varied across simulations of road ditchflow and streamflow. DHSVM simulations for two streamflow locations varied outside the uncertainty bounds for 10%–22% of storm volumes and 12%–22% of peak flows, respectively. Twenty-eight percent to 52% of storm volumes and 28%–48% of peak flows were outside the uncertainty bounds for the six road ditchflow locations.

Using FORSEE and Continuous Forest Inventory Information to Evaluate Implementation of Uneven-aged Management in Santa Cruz County Coast Redwood Forests

Douglas D. Piirto et al. — Tue, 13 Nov 2012 11:02:37 PST

Swanton Pacific Ranch in northern Santa Cruz County has been owned and managed by California Polytechnic State University (Cal Poly) Foundation since 1987. The California Forest Practice Rules specific to Santa Cruz County limit harvest rate and opening size. Cal Poly forest managers are implementing uneven-aged forest management on 1,182 acres of 80 to 110 year old, second-growth coast redwood forests using a modified BDq approach. The Lockheed Fire spread into most of the managed forest area during the summer of 2009 causing significant mortality in lower diameter classes.

Biological and Management Implications of Fire-Pathogen Interactions in the Giant Sequoia Ecosystem

Douglas D. Piirto et al. — Thu, 30 Aug 2012 15:06:40 PDT

An overriding management goal for national parks is the maintenance or, where necessary, the restoration of natural ecological processes. In Sequoia-Kings Canyon and Yosemite National Parks, there is concern about the effects of fire suppression on the giant sequoia-mixed conifer forest ecosystem. The National Park Service is currently using prescribed fire management and prescribed burning as tools to reintroduce fire as a natural process. However, there are questions about the positive and negative effects of reintroducing fire in the giant sequoia-mixed conifer ecosystem. Reintroducing fire in the Sierra Nevada forests needs critical evaluation with respect to the pathogens that affect giant sequoias. We designed a 3-year study, funded by the U.S. Department of the Interior, National Park Service, to: (1) determine the effects of fire scars and their re-burning on the incidence, extent, and survival of fungi in giant sequoia; (2) identify pathogens, insects, location of decay, and other characteristics present in standing old-growth giant sequoia fire scars; (3) evaluate host specialization and cross infectivity of isolates of Heterobasidion annosum from white fir (Abies concolor), red fir (Abies magnipca), and giant sequoia (Sequoia gigantea); and (4) develop criteria and recommendations for monitoring the effects of fire on pathogens in giant sequoia stands. The total circumference of giant sequoia trees affected by fire scars ranged from 3.3% to 69.5%. Cross-sectional area affected by fire scars ranged from 3.2% to 53.7%. The season of year in which prescribed burning takes place could influence the effect fire has on giant sequoia. A survey of 90 fire scars for the presence of resin, MycocaIicium, carpenter ants, other insects, Arachnids, decay above and below groundline, and bird activity (i.e., cavities) yielded a high presence of each factor when all burn groups were combined. Statistically significant differences in bird cavity activity, decay above groundline, and carpenter ant activity were noted among the unburned group, 1-year burn group, and 5-year burn group. The Pilodyn wood tester was effective in determining the presence of decay above and below groundline. A variety of microfungi were found associated with giant sequoia fire scars. The fungi most frequently isolated were: Byssochlamys fulva from 34 out of 90 fire scars (38%), Acrodontium intermissum from 22 out of 90 fire scars (24%), and Tritirachium sp. from 14 out of 90 fire scars (16%). Several other microfungi and Basidiomycetes were also identified. H. annosum acts as both a saprophyte and a pathogen in the giant sequoia-mixed conifer ecosystem. The results of these experiments have demonstrated H. annosum can spread from true fir to giant sequoia and vice versa, given that they are of the same ”S” intersterility group.

Identifying and Addressing Contemporary Issues in Central Coast Oak Woodlands

Erin Rice et al. — Thu, 30 Aug 2012 15:06:39 PDT

Recently, questions about the extent of thinning, the sustainability of forest management practices, and the compatibility with other uses were raised by the media, agency personnel, and environmental groups. In response, University of California Cooperative Extension and Cal Poly San Luis Obispo’s Natural Resources Management Department collaborated to address these issues. In March 2006, a questionnaire was mailed to landowners of properties greater than 100 acres in Santa Barbara, San Luis Obispo, and Monterey counties. A total of 2,786 questionnaires were mailed, with 450 completed and returned (16 percent). The respondents were highly educated, holding degrees in areas other than agriculture or natural resources. Most landowners earned degrees in biology, business, education, law, engineering, or medicine. Over 60 percent of respondents were opposed to any county ordinance. However, 71 percent of respondents said oaks are “important” for their aesthetic value, which indicates support for oak protection. Responding landowners feared the loss of private property rights, and felt that government should not interfere with management on private property. Nearly 73 percent of respondents to our survey make less than 25 percent of their income from their land. Landowners rated their knowledge of oak products marketing, laws and regulations (e.g., Forest Practices Act), forest health (e.g., Sudden Oak Death), and available consulting services as especially poor. A majority of landowners who responded to the survey did not know how to get more information on oak woodland management. The workshop presented on August 17, 2006, in San Luis Obispo, was designed to respond to issues and information needs identified by central coast landowners as well as to provide the latest scientific findings and policies regarding oak woodland management.

Watershed study results offer strategies for reducing erosion and sedimentation associated with cattle grazing

Lynn E. Moody — Mon, 12 Dec 2011 15:00:16 PST

The Morro Bay estuary is arguably the most important wetland system on the south central coast of California. It supports commercial fishing industries, numerous recreation activities, and a variety of natural habitats. The estuary and its watershed, representing a diverse biological and economic resource to the people of California, are impacted by various pollutants, with sediment of particular concern. As part of a 10-year national monitoring program funded by the U.S. Environmental Protection Agency (EPA) through California's Regional Water Quality Control Board (Regional Board), a paired watershed study on California Polytechnic State University's Escuela Ranch has shown that Best Management Practices (BMPs) aimed at reducing erosion and sedimentation associated with cattle grazing appear to result in improvement of water quality. The same BMPs have resulted in an increase in residual vegetation that is harvested by the cattle during the dry season. The objective of this study was to extend monitoring of hydrology and water quality for an additional year, and to monitor range forage quality (protein and fiber) for three years.

Geomorphic and pedogenic evolution in coastal sediments, central California

Lynn E. Moody et al. — Mon, 12 Dec 2011 15:00:10 PST

Studies of soil chronosequences on marine terraces facilitate the use of terraces for tectonic and paleoclimatic interpretation. However, many areas on the California coast have received substantial eolian deposits after pedogenesis began, so do not qualify as chronosequences. These areas are worthy of study because they are widespread coastal landscape features, and they enable us to interpret pedogenic and geomorphic processes in sandy regolith. The objective of this study was to use soil and deep regolith morphology and chemistry to interpret pedogenic and geomorphic evolution on a sequence of four marine terraces, San Luis Obispo County, California. The terraces are numbered I, 2, 3, and 4, from oldest to youngest. The eroded terrace platforms have been tentatively dated at 560, 420 or 480,320, and 120 ka, respectively. The sand deposits on each platform may be considerably younger. The amount of land surface dissection and the depth of stream incision increase with increasing terrace age and elevation. Morphological features suggest that the soils (Xeropsamments on Terrace 4, Haploxerolls on Terrace 3) on the two youngest terraces are well drained, and their morphological development is typical of soils in eolian sand deposits. Morphological and chemical features of the basal regolith contrast with those of the soils. Clay, Fe oxides, and opaline silica were deposited by groundwater flow above the bedrock platform. Above the shoreline angle, where the deep regolith receives additional groundwater from higher terraces; redoximorphic features have developed. Gray mottles are larger, more common, and more distinct in the basal regolith of progressively older terraces. Erosion has removed much of the overburden on Terraces 2 and I, and soils (Epiaquolls on Terrace 2, Epiaqualfs on Terrace I) have developed in what was once deep regolith. The landscape, soils, and deep regolith show an evolution of processes, whereby the path and direction of water movement through the regolith is controlled first by terrace morphology and stratigraphy, then by the development of pedogenic features in the soil and deep regolith, and by terrace dissection.