Treesearch

In recent years, forest management in the Pacifi c Northwest has shifted from one based largely on resource extraction to one based on ecosystem management principles. Forest management based on these principles involves simultaneously balancing and sustaining multiple forest resource values, including silvicultural, social, economic, and ecological objectives. Leave islands, or green-tree retention clusters, have been proposed as an alternative silvicultural strategy designed to sustain the ecological integrity and biological diversity within intensively managed forests. However, pertinent...

Presentation Abstract Old-growth Douglas-fi r (Pseudotsuga menziesii) forests are a goal for conservation and restoration across millions of acres of federal forest lands in western Oregon and Washington. Where old growth currently exists, management is typically focused on protecting stands and watersheds from logging and high-severity wildfi re. Where old growth was converted to Douglas-fi r plantations during the 20th century, the goal is often to actively manage those areas to create ecological diversity and accelerate development of old-growth conditions. What does it mean to use old...

Th inning stands (managing their densities) aff ects the development of trees and understory plants as individuals, as well as stand-level characteristics like structure, microclimate, and stand growth, habitat for various species, and fuel and potential fi re severity. Th ese characteristics and the rate of changes are aff ected by thinning severity—the reduction in numbers of trees, the stand density, and also by the number, sizes, species, and growth rates of the trees retained. In addition, site variables like potential for severe wind and ice/snow storms, soil depth/rooting, root...

To understand the impacts of overstory density reductions on resilience of forest ecosystems (i.e., the capacity of an ecosystem to maintain desired ecosystem functions in a fl uctuating environment), we examined overstory basal area and understory vegetation cover and richness collected 6 years after thinning in seven 40- to 60-year-old forests dominated by Douglas-fi r (Pseudotsuga menziesii (Mirb.) Franco) in the Oregon Coast Range and Cascade Range of western Oregon. Each site contained an unthinned control (240–1,540 trees∙ha-1 [tph]) and three thinning treatment units (high-density =...

Public agencies in the Pacifi c Northwest have engaged in managing for late-successional features or structure on lands which also have the possibility for high timber production. Th is study examined the potential for developing understory structure while maintaining a productive overstory on two sites (Willamette Valley foothills and coastal) in western Oregon. Treatments included thinning 50- to 55-year-old Douglas-fi r (Pseudotsuga menziesii) or Douglas-fir/Western Hemlock (Tsuga heterophylla) stands to three or four overstory densities 30 to 65 percent below full stocking, either in a...

At the conclusion of the workshop, a breakout group session discussed common themes that had emerged regarding forest degradation monitoring in the Southeast Asia region. The participants were also asked to list any important issues that may not have been sufficiently addressed during the workshop and that may require further discussion, and recommendations for next steps in moving forest degradation monitoring forward in the region were developed.

Monitoring forest degradation is a complex process that needs to account for a wide variety of forest characteristics, human activities, and programmatic resources in order to achieve reliable results. This workshop sought to deepen understanding of monitoring forest degradation as it relates to these issues by: a) discussing implications from definitions related to operationalizing forest monitoring degradation; b) assessing case studies with current, and emerging, best practices to detect and monitor forest degradation; and, c) identifying ways forward for forest degradation monitoring...

This presentation will provide an overview of an approach for quantifying uncertainty in spatial estimates of carbon emission from land use change. We generate uncertainty bounds around our final emissions estimate using a randomized, Monte Carlo (MC)-style sampling technique. This approach allows us to combine uncertainty from different sources without making assumptions about the distribution of the underlying data. We incorporate uncertainty from the following components: Estimates of forest loss; Estimates of aboveground biomass; and Estimates of belowground biomass. In each scenario...

Techniques for monitoring deforestation and associated changes to forest carbon stocks are widespread and well published. In contrast, techniques for monitoring forest degradation are relatively untested in developing countries despite their inclusion in UNFCCC REDD+ negotiations. In the Mekong countries, forest degradation may contribute a substantial portion of the total carbon losses from forests. There is a critical need to assess approaches for monitoring forest degradation, particularly at the subnational level. One potential obstacle in assessing monitoring approaches for the region...

Conversion of natural forest to agricultural land is one of the most important forms of land-use change affecting both carbon stock and biodiversity. When the agricultural land contains trees, e.g. fallow-land forest of slash-and-burn agriculture, the conversion can be categorized into forest degradation when the forest definition covers such vegetation. One practical method to monitor carbon stock change is an approach using a parameter for plant community age. For cyclic land use that includes clear-cutting stage, from which chronosequential changes in carbon stock can be estimated by...