Treesearch

An integrated 3D log processing optimization system was developed to perform 3D log generation, opening face determination, headrig log sawing simulation, fl itch edging and trimming simulation, cant resawing, and lumber grading. A circular cross-section model, together with 3D modeling techniques, was used to reconstruct 3D virtual logs. Internal log defects (knots) were depicted using a cone model with apex at the central axis of the log. Heuristic and dynamic programming (DP) algorithms were developed to determine the best opening face, primary log sawing, edging and trimming, and cant...

The summer of 2008 brought the first wildfires to occur in known Phytophthora ramorum-infested forests in California, with the largest individual fire burning in the Big Sur region of the central coast (Monterey County) (Metz et al. 2011). More than 100,000 ha in Big Sur were ultimately burned that summer, providing a natural experiment to examine the feedbacks between a destructive, invasive forest pathogen and wildfire. Big Sur is one of the most botanically and ecologically diverse areas in California, and its forests were among the earliest infested and most impacted by sudden oak...

Invading species can alter ecosystems by impacting the frequency, severity, and consequences of endemic disturbance regimes (Mack and D'Antonio 1998). Phytophthora ramorum, the causal agent of the emergent disease sudden oak death (SOD), is an invasive pathogen causing widespread tree mortality in coastal forests of California and Oregon. In the absence of the pathogen, species composition in these forests is shaped by a number of biotic and abiotic factors, including wildfire. Large wildfires in California in 2008 provided an opportunity to test the interactions between P. ramorum and...

Sudden oak death has impacted forests notable for high-fire risk and contiguous host communities in California and Oregon coastal forest ecosystems. The disease continues to emerge in stands and landscapes with a large biomass of tanoak (Notholithocarpus densiflorus (Hook.&Arn.) Manos, Cannon & S.H.Oh), and we show that woody debris also increases with the progression of disease. This increase in fuels and the possibility of increased carbon release may impact wildfire intensity, wildlife, and regional carbon management goals (Cobb et al. 2012a, Lamsal et al. 2011, Valachovic et al. 2011).

Although it has been convincingly shown that forest populations of the pathogen Phytophthora ramorum have undergone a significant bottleneck and reproduce exclusively asexually (Ivors et al. 2004, 2006; Mascheretti et al. 2008), objective results showing that nurseries were the original source of the introduction remain elusive (Mascheretti et al. 2008). A previous attempt to define routes of pathogen movement resulted in a largely unresolved network (Mascheretti et al. 2009), showing at best that populations from Santa Cruz and Marin Counties were important sources within California....

Reduced-impact forestry uses best management practices (BMPs) during operations to minimize soil erosion and sediment delivery to streams and to maintain or improve site productivity. However, the efficacy of specific types of BMP implementation is not widely documented. This review synthesizes recent research that investigated contemporary BMP implementation and effectiveness in water quality protection associated with the following forest management operations: forest roads and skid trails, streamside management zones, harvesting, site preparation, and stream crossings. The review...

To evaluate surface water withdrawals used for Marcellus shale natural gas development and to assess potential impacts on water yield, a regional water balance model was developed for the Pine Creek watershed, located primarily in Lycoming County, Pennsylvania. Marcellus shale development has increased rapidly in Lycoming County since 2007. We used precipitation, potential evapotranspiration, and streamflow from a long-term U.S. Geological Survey station to estimate surface water availability and characterize seasonal changes over a 50-year period. We compared water availability and demand...

The integration of factors and processes responsible for streambank erosion is complex. To explore the influence of physical variables on streambank erosion, parameters for the bank assessment of nonpoint source consequences of sediment (BANCS) model were collected on a 1-km reach of Horseshoe Run in Tucker County, West Virginia. Cluster analysis was used to establish groups of streambanks, and observed erosion between the groups was compared. The cluster analysis revealed that groups of streambanks with uniform bank composition, high surface protection, low bank angles, and intermediate...

Th e Appalachian Region has a long history of natural resource management and recurrent history of frequent and large-scale floods. Land use activities such as urbanization, mining, forest harvesting, and agriculture can have a noticeable effect on the volume, magnitude, timing, and frequency of floods. Determining the effects of land use on flooding is difficult for many reasons, and there are no exact methods of identifying the impacts of land use on flood generation across larger scales. To ascertain the potential effects of land use changes on fl ooding in this region, a flood productio...

Many Phytophthora species, including Phytophthora ramorum, have been reported from surface waters such as canals, streams, rivers, ponds, and reservoirs, often in association with infested agricultural or natural landscapes (Hong and Moorman 2005). Phytophthora species are recovered with regularity and abundance from streams and rivers, in many cases in the absence of apparent terrestrial infestations (Hwang et al. 2010, Reeser et al. 2011, Sutton et al. 2009), or under conditions not conducive to sporulation in the landscape in the case of California summers. This strongly suggests that...