Treesearch

The Pacific Northwest (PNW) of the conterminous United States is characterized by large variations in climate and topography, and provides an ideal geographic domain for studying interactions between regional climate and vegetation dynamics. We examined vegetation carbon (C) and water dynamics along PNW climate and topographic gradients using a process-based biogeochemical model, BIOME-BGC, the algorithms of which form bases for a fully-prognostic treatment of carbon and nitrogen cycles in Land Community Model (CLM). Simulation experiments were used to (1) analyze spatial and temporal...

Participatory mapping of landscape values is gaining ground as a method for engaging communities and stakeholders in natural resource management. Socio-spatial mapping allows the public to identify places of economic, social, cultural, or personal importance. In addition to providing data for planning and land management, the mapping process can open dialogue about interests and concerns related to specific places. This paper presents the collaborative development and results of a values mapping exercise with a Latino community on the Olympic Peninsula in Washington State. While mapping...

We synthesize the biology and ecology of the Cope's giant salamander. We have conducted the first compilation of known sites for the species, to aid status assessments and conservation planning. Known and suspected threats to the species are summarized. Considerations for species and species-habitat management are provided.

We provide a comprehensive synthesis of the biology and ecology of the Van Dyke's Salamander, review known and suspected threats, and outline alternative management considerations. This species is agency sensitive and is listed as a Survey and Manage species under the Northwest Forest Plan. This document will aid Forest Service Region 6 forest managers and biologists in planning for projects within the species range in Washington, especially on National Forests in the Olympic Peninsula and Cascade Range.

Pecan (Carya illinoiensis) and white oak (Quercus alba) produce multiple products and wildlife values, but their phenological responses to N fertilization have not been well characterized. We compared tree growth at planting and for six consecutive growing seasons during establishment (2003–2008, Test 1), and determined if phenology of budburst, leaf area index (LAI), quantum yield of photosystem II (Fv/Fm), radial growth, and total chlorophyll concentration (a, b) responded to poultry litter fertilization supplying 0, 50, and 100 kg ha-1N(2010–2012, Test 2) in a mixedspecies orchard on an...

Questions: Do successional trajectories in plant diversity, heterogeneity and dominance respond differently to ungulate exclusion in unmanaged forests vs managed forests that are thinned and burned? Is vegetation in recently thinned and burned standsmore sensitive to changes in the grazing regime? Location: Northeast OR, USA. Methods: We evaluated changes in plant community composition, diversity, heterogeneity and dominance under herbivory by multiple ungulates (cattle, elk, deer) vs ungulate exclusion at sites where trees were recently thinned and a prescribed burn was applied (managed),...

Field and greenhouse studies examined the effects of growth habit and chloroplast presence in leaf veins for their role in increasing agronomic water use efficiency and yields of California modern processing tomato (Solanum lycopersicum L.) cultivars. Five introgression lines (ILs), made with Solanum pennellii Cor. in the genetic background of cultivar M82, differ in genes that map to a region on Chromosome 5, including the SP5G gene (determinate vs. semideterminate (Det vs. SemiDet)) and the obv gene (presence (obscure) vs. absence (clear) of leaf vein chloroplasts (Obs vs. Clr)). The...

Advancing the recovery of large-scale ecosystems, such as the Puget Sound inWashington State, requires improved knowledge of the interdependencies between nature and humans in that basin region. As Biedenweg et al. (this issue) illustrate, human wellbeing and human behavior do not occur independently of the biophysical environment. Natural environments contribute to human wellbeing through ecosystem services and humans influence natural environments through their behaviors. Historically, however, conservation and the recovery of degraded natural systems has been the purview of natural...

Leaf hydraulics, gas exchange and carbon storage in Pinus edulis and Juniperus monosperma, two tree species on opposite ends of the isohydry–anisohydry spectrum, were analyzed to examine relationships between hydraulic function and carbohydrate dynamics. Leaf hydraulic vulnerability, leaf water potential (Ψl), leaf hydraulic conductance (Kleaf), photosynthesis (A), stomatal conductance (gs) and nonstructural carbohydrate (NSC) content were analyzed throughout the growing season. Leaf hydraulic vulnerability was significantly lower in the relatively anisohydric J. monosperma than in the...

Despite the critical role that phloem plays in a number of plant functional processes and the potential impact of water stress on phloem structural and phloem sap compositional characteristics, little research has been done to examine how water stress influences phloem transport. The objectives of this study were to develop a more accurate understanding of how water stress affects phloem transport in trees, both in terms of the short-term impacts of water stress on phloem sap composition and the longer-term impacts on sieve cell anatomical characteristics. Phloem sieve cell conductivity...