Treesearch

Alnus maritima (Marsh.) Muhl. ex Nutt. ssp. oklahomensis Schrader & Graves has potential for ornamental use in the Intermountain West. Because this taxon is native to low-elevation wetlands, we sought to determine its response to the dry soils and climate of northern Utah. Although seeds sown directly at three non-irrigated sites in northern Utah either did not germinate or germinated and died, seeds planted in a greenhouse in soils from the three sites did germinate and survive. Hardened plants grown from these seeds and installed at the same three sites overwintered, broke bud and leafed...

Spanhove and Lehouck raise several excellent points in their critique of "Forest Health Monitoring in the Ngangao Forest, Taita Hills, Kenya: A Five Year Assessment of Change" (JEANH 97(1): 3-17). Their central argument, that Rogers et al. neglected monitoring of invasive alien species in their assessment of 'forest health', cannot be disputed. Though we briefly address the influence of endemic trees (specifically pioneer species), and contrast those influences between Chawia (a highly disturbed forest) and Ngangao (a moderately disturbed forest), we do not extend our assessment to other...

An initial assessment of rapid dieback and mortality of aspen in southwest Colorado suggests that it represents a decline disease incited by acute, warm drought. Predisposing factors include low elevation, south and southwest aspects, droughty soils, open stands, and physiological maturity. Contributing factors include Cytospora canker, two bark beetles, poplar borer, and bronze poplar borer. Because this is a true decline disease distinct from "aspen decline" as often discussed in the literature, we refer to it as sudden aspen decline. There has been little regeneration response to...

In the ponderosa pine forests of the northern Front Range of Colorado, downed woody debris amounts, fuel arrangement, and stand characteristics were assessed in areas infested with southwestern dwarf mistletoe (Arceuthobium vaginatum subsp. cryptopodum), mountain pine beetle (Dendroctonus ponderosae) and Ips spp. One hundred fifty plots, each 0.04 ha, were measured and an ANCOVA and Tukey's Multiple Comparison Procedure were used to assess differences in plots with high infestation level compared to plots with trees not infested. Dwarf mistletoe contributed more to the fuel arrangement...

This is a preliminary, draft outline for organizing information on the relation of climate to western forest diseases. The question is how to assess the threat of these diseases under a regime of climate change. Although forest diseases are often important, assessment of disease-climate relations is a challenging problem due to the multiple values at risk and the complexity of these systems. Several approaches are described and illustrated with examples for mistletoes and stem rust. Only a sampling of examples is given to illustrate a variety of concepts; many additional examples are to be...

Relatively little quantitative information has been available on the effects of low-intensity fire (under-burning) on dwarf mistletoe. Here we summarize results from six operational prescribed under-burns in second-growth ponderosa pine in New Mexico (Conklin and Geils, in press). For 1585 trees on 14 plots, crown scorch, bole char, and DMR were significant predictors of post-burn survival in both logistic (3-yr response) and proportional hazard models (over 6 to 10 yrs). Reduction in DMR on surviving trees (scorch pruning) increased linearly with increasing scorch. Reduction in average...

This is a preliminary, draft outline for organizing information on the relation of climate to western forest diseases. The question is how to assess the threat of these diseases under a regime of climate change. Although forest diseases are often important, assessment of disease-climate relations is a challenging problem due to the multiple values at risk and the complexity of these systems. Several approaches are described and illustrated with examples for mistletoes and stem rust. Only a sampling of examples is given to illustrate a variety of concepts; many additional examples are to be...

The U.S. Forest Service (Forest Service) has a long, shared history with the land grants of northern New Mexico. During the land grant adjudication process after U.S. conquest, much common land from both Spanish and Mexican land grants was declared public domain, eventually becoming part of the northern and central New Mexico National Forests. These forests were established during the late 1800s and early 1900s. Other lands went into private ownership and were later sold to the government. This paper focuses on the contemporary situation concerning land grants and the Forest Service. We...

The cingulum is a U-shaped structure of unknown function which arises between abdominal sterna 4 and 5 and terminates in a pair of variously modified flag-like appendages. This structure is well developed only in males of the genus Scellus. Richard Hurley discovered that Hydatostega have a much reduced cingulum, a finding that had broad implications for elucidating hydrophorine phylogeny. Rich suggested that the size and bright coloration might serve a visual signaling function, whereas the arrangement of hairs suggests a pheromone-dispersing function.

Richard Lester Hurley, dolichopodid worker and friend to everyone, passed away on September 3rd at the age of 74. He was born on June 22, 1934 in Sault Ste. Marie, Ontario and received a B.A. in biology from Queen's University in Kingston, Ontario in 1957. For his senior thesis, he conducted an insect survey of the Lake Opinicon region. Rich spent the summers of 1957-58 working for Agriculture Canada; collecting insects in the Northwest Territories for the Northern Insect Survey in 1957, and in southern Manitoba in 1958. It was during these two summers that his interests were confidently...