Treesearch

Stem decays of living trees, known also as heart rots, are essential elements of wildlife habitat, especially for cavity-nesting birds and mammals. Stem decays are common features of old-growth forests of coastal Alaska, but are generally absent in young, managed forests. We offer several strategies for maintaining or restoring fungal stem decay in these managed forests that can be used to enhance specific types of wildlife habitat.

Carbon storage and flux estimates for the two national forests in Alaska are provided using inventory data from permanent plots established in 1995–2003 and remeasured in 2004–2010. Estimates of change are reported separately for growth, sapling recruitment, harvest, mortality, snag recruitment, salvage, snag falldown, and decay. Although overall aboveground carbon mass in live trees did not change in the Tongass National Forest, the Chugach National Forest showed a 4.5 percent increase. For the Tongass National Forest, results differed substantially for managed and unmanaged forest:...

The pathway of radial water movement in tree stems presents an unknown with respect to whole-tree hydraulics. Radial profiles have shown substantial axial sap flow in deeper layers of sapwood (that may lack direct connection to transpiring leaves), which suggests the existence of a radial pathway for water movement. Rays in tree stems include ray tracheids and/or ray parenchyma cells and may offer such a pathway for radial water transport. This study investigated relationships between radial hydraulic conductivity and ray anatomical and stem morphological characteristics in the stems of...

The Density Management Study and Young Stand Th inning and Diversity Study were initiated to investigate whether alternative thinning treatments can accelerate the development of forests toward late-successional structures. An overview of overstory and understory vegetation responses indicates that the magnitude and direction of thinning eff ects initially varied among structural stand components. Average crown length, diameter growth, and seedling and sapling density increased rapidly after thinning. However, diameter growth of the largest trees was less responsive to thinning, at least...

Tree mortality shapes forest structural development and the resulting dead wood provides habitat for many species. However, the eff ects of thinning on mortality and large snag recruitment have been variable and remain poorly understood. We examined thinning eff ects on tree mortality at eleven Density Management Study (DMS) sites in western Oregon. Th inning reduced mortality rates for small trees, especially Douglas-fi r (Pseudotsuga menziesii), but had little infl uence on mortality of large trees (¡Ý50 cm dbh). Gaps created by harvest did not result in increased mortality during the...

Accurate estimates of foliar biomass (FB) are important for quantifying carbon storage in forest ecosystems, but FB is not always reported in regional or national inventories. Foliar biomass also drives key ecological processes in ecosystem models. Published algorithms for estimating FB in conifer species of the Pacific Northwest can yield signifi cantly different results, but have not been rigorously compared for species other than Douglas-fi r (Pseudotsuga menziesii (Mirb.) Franco). We compared fi ve algorithms for estimating FB for seven common coniferous species in the Pacifi c...

The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), causes the infectious disease chytridiomycosis, which has triggered massive die-offs and extinctions of amphibians around the world. The disease, identified in 1998, is a significant contributor to the global amphibian biodiversity crisis, and no clear means of arresting its spread has been found. Conservationists, scientists, and wildlife managers are grappling with understanding the extent and severity of chytrid disease and its ramifications on species and ecosystems. Enlisting collaborators around the world, Dede Olson,...

Long-term ecological data are crucial in helping ecologists understand ecosystem function and environmental change. Nevertheless, these kinds of data sets are difficult to analyze because they are usually large, multivariate, and spatiotemporal. Although existing analysis tools such as statistical methods and spreadsheet software permit rigorous tests of pre-conceived hypotheses and static charts for simple data exploration, they have limited capacity to provide an overview of the data and to enable ecologists to explore data iteratively, and interactively, before committing to statistical...

This guidebook describes Upper Elk Meadows Research Natural Area (RNA), a 90-ha (223-ac) area that supports a mixture of coniferous forest and open, shruband herb-dominated wetlands. The major forest plant association present within Upper Elk Meadows RNA is Pacific silver fir/vine maple/coolwort foamflower (Abies amabilis/Acer circinatum-Tiarella trifoliata).