Treesearch

The perception and measurement of the risk of natural disturbances often varies depending on the spatial and temporal scales over which information is collected or analyzed. This can lead to conflicting conclusions about severity of current or past disturbances or the risk of future ones. Failure to look across scales also complicates local implementation of policies developed from broad-scale perceptions of risk because perception of risk is relative and depends on context. Methods that help policymakers, managers, and the public look across spatial and temporal scales can improve their...

Field ectomycorrhizas of Cortinarius helodes Moser, Matheny & Daniele (sp. nov) and Gyrodon monticola Sing. on Alnus acuminata Kunth (Andean alder, aliso del cerro) are described based on morphological and anatomical features. Ectomycorrhizal roots were sampled beneath fruitbodies of C. helodes and G. monticola from two homogeneous A. acuminata forest sites located in Tucuman and Catamarca Provinces in Argentina. C. helodes ectomycorrhizas showed a thick white to beige mantle exuding a milky juice when injured, were bluish toward the apex, and had hyphal strands in the mantle. G. monticola...

Many small cities and towns are located near resource lands, and their central business districts serve both residents and visitors. Such quasi-rural retail centers face competitive challenges from regional shopping malls, online purchasing, and big box discount retailers. District merchants must strategically enhance their market position to prevent outshopping. Streetscape trees are a physical improvement that can be used to attract and welcome consumers. A national survey evaluated public perceptions, patronage behavior intentions, and product willingness-to-pay in relationship to...

A multistudy research program has investigated how consumers respond to the urban forest in central business districts of cities of various sizes. Trees positively affect judgments of visual quality but, more significantly, may influence other consumer responses and behaviors. Survey respondents from all regions of the United States favored trees in business districts, and this preference was further reflected in positive district perceptions, patronage behavior, and product pricing. An overview of the research is provided, with implications for the economics of local communities.

We investigated post-fire morels (Morchella species), especially the "gray" morels of Idaho and Montana, bycollecting ecological and genetic data and by interviewing commercial mushroom harvesters and buyers. Graymorels fruited exclusively in high-elevation Picea/ Abies forests that had burned the preceding summer,predominantly in zones of moderate fire intensity as indicated by a layer of dead conifer needles on top of the fireash. Genetic analysis revealed five varieties of morels among our specimens. Mushroom harvesters confirmed thatgray morels are economically crucial to their...

Decreased nest success and elevated levels of nest predation have been linked to changes in landscape configuration and increased edge. Using radiotelemetry and artifical nests, we studied the ranging and nest-predation behavior of the Steller's jay (Cyanocitta stelleri) in the managed forests of western Washington. Steller's jays did not appear to use a specialized search strategy to find nests, although they were ca[ab;e pf performing area-restricted serching for other food items. By equating relative abundance of Steller's jays with nest predation risk, managers can map...

In their interesting research on post-fire foraging behaviour of northern bettongs (Bettongia tropica) in tropical Queensland, Australia, Vernes et al. (2004) used forage-diggings of their study animals to locate plots for estimating biomass of hypogeous fungi on prescribed-burnt sites in comparison with unburnt control sites. They concluded that within a few weeks after each experimental fire, biomass on burnt sites peaked at very high levels compared with unburnt sites, and then decreased markedly to very low levels within 2-3 months post-fire. The peak in biomass on burnt sites was...

We investigated the occurrence of, and relationships among, snags and cavity-nesting birds in the rapidly urbanizing region around Seattle, Washington in 2001 and 2002. We measured the density of snags in 49 sites (1-km2 "suburban landscapes" that included built and forested portions), and determined the diameter, height, decay status, and species of individual snags. We spot-mapped territories and observed nests of cavity-nesting birds at a stratified, random subsample of 13 sites. Snags, especially red alder (Alnus rubra), were abundant in sites' forested portions, but rare in the built...

Lyman glacier in the North Cascades Mountains of Washington has a subalpine forefront characterized by a well-developed terminal moraine, inconspicuous successional moraines, fluting, and outwash. These deposits were depleted of symbiotic fungi when first exposed but colonized by them over time after exposure. Four major groups of plant species in this system are (1) mycorrhizaindependent or facultative mycotrophic, (2) dependent on arbuscular mycorrhizae (AM) (3) dependent on ericoid mycorrhiza (ERM) or ectomycorrhizae (EM), and (4) colonized by dark -septate (DS) endophytes. We hypothesiz...

Phosphorus (P) availability has generally been assumed to be the limiting or co-limiting factor for plant growth in alpine environments. To test this assumption, the biogeochemistry of phosphorus (P) along an alpine topographic/snow gradient located on Niwot Ridge, Colorado Front Range was studied in the context of P limitation for plant growth. We measured the various P pools using a selective extraction procedure, determined sorption parameters, and quantified P availability indices. The topographic/snow gradient at Niwot Ridge is divided by the aspect and slope position in relation to...