Treesearch

Post-treatment erosion was observed for 41 decommissioned road stream crossings in three northern California watersheds. Sites were purposefully selected in order to characterize the nature and range of post-treatment erosional responses. Sites with the highest visible erosion were selected in order to better understand the dominant process and incorporate any lessons learned into future projects. Sites were also intentionally selected where post-treatment erosion appeared to be negligible, or excavation techniques were judged be have been fully effective at removing erodible material. In...

Increasingly private landholders in Hawaii are considering native forest restoration for their lands, and some public agencies have already started such work. Initial efforts have focused on reestablishing Acacia koa to recover alien-grass-dominated sites. This study was done in Hakalau Forest National Wildlife Refuge, Island of Hawaii, to determine the efficacy of disk plowing to stimulate natural regeneration of koa from buried seeds. Sites with four different koa parent tree configurations were treated–single live overhead koa canopy, multiple live canopies, downed snags, and no parent...

Reducing stand density is often used as a tool for mitigating the risk of high-intensity crown fires. However, concern has been expressed that opening stands might lead to greater drying of surface fuels, contributing to increased fire risk. The objective of this study was to determine whether woody fuel moisture differed between unthinned and thinned mixed-conifer stands. Sections of logs representing the 1000- and 10 000-h fuel sizes were placed at 72 stations within treatment units in the fall (autumn) of 2007. Following snow-melt in 2008, 10-h fuel sticks were added and all fuels were...

A central challenge to studying emerging infectious diseases (EIDs) is a landscape dilemma: Our best empirical understanding of disease dynamics occurs at local scales, whereas pathogen invasions and management occur over broad spatial extents. The burgeoning field of landscape epidemiology integrates concepts and approaches from disease ecology with the macroscale lens of landscape ecology, enabling examination of disease across spatiotemporal scales in complex environmental settings. We review the state of the field and describe analytical frontiers that show promise for advancement,...

The restoration of native plant diversity may be an effective tool for weed control, but its use has not been tested in the heavily invaded Hawaiian dry forest ecosystem. In addition, the ecological mechanisms by which invasive plants may cause declines in native plant diversity are generally not well understood. We examined invasion resistance and the relationships between invasion and declines in native plant diversity at local scales in a Hawaiian dry forest restoration by experimentally removing non-native species, planting native species, manipulating resources and environmental...

Although many sediment budgets estimate the effects of logging, few have considered the potential impact of timber harvesting on stream density. Failure to consider changes in stream density could lead to large errors in the sediment budget, particularly between the allocation of natural and anthropogenic sources of sediment. This study conducted field surveys in randomly selected catchments in two managed and one old-growth watershed to determine the location of the channel's origins in the catchments. The drainage areas for identified channel heads were then delineated using a 1 m...

We conducted a research needs assessment (RNA) in 2010 to gather opinions of "experts" and a larger public on research priorities for Phytophthora ramorum, the pathogen that causes sudden oak death in forest trees and Ramorum blight in ornamental plants. We place these 2010 findings in context with findings of similar P. ramorum needs assessments from 2002 and 2007-2008 and with a comprehensive literature review published in 2010. P. ramorum research needs have evolved from an emphasis on basic biological information toward an emphasis on management. As with many other non-native, invasive...

One hundred and nine years after the first redwoods were set aside in public ownership, the redwood movement has come a long way. For most of the public, "saving redwoods" has meant placing threatened giants in parks and reserves—Big Basin State Park (1902), Muir Woods National Monument (1908), Humboldt Redwoods State Park (1921), Redwood National Park (1968), and the Headwaters Forest Reserve (1999). But after a century when more than 95 percent of the ancient redwoods were felled and most of the large groves are protected in public parks and reserves, what does it mean to save the...

One of the predominate water quality problems for northern coastal California watersheds is the impairment of salmonid habitat. Most of the North Coast watersheds are listed as “impaired” under section 303(d) of Clean Water Act. The Clean Water Act requires states to address impaired waters by developing Total Maximum Daily Loads (TMDLs) or implementing another program that will result in the attainment of water quality standards. TMDLs are an estimate of the maximum load necessary to meet water quality standards. In a general sense, a TMDL and its implementation plan is a water quality...

The Coast Redwood Forests in a Changing California Science Symposium was held June 21-23, 2011 at UC Santa Cruz with just under 300 registrants in attendance. Participants ranged in background from graduate level students to university forestry faculty, land managers, and conservation groups, public agencies, and land trust members. The symposium was strategically held in Santa Cruz, near the Southern end of the redwood region. Designed to present the state of our knowledge about California's coast redwood forest ecosystems and sustainable management practices, this symposium was built on...