Quantifying biomass is important for sustainable forest management. The purpose of this study is to obtain allometric relationships for seven species of shrubs common in northeastern California so that estimates of carbon and fuel loading may be better realized. Although some shrub biomass equations exist, such equations are limited in...
Disturbances are a prevalent and important part of ecosystems. Many landscape patterns that we find today were created, maintained, and changed by natural disturbance regimes. This is especially true for fire, which has historically been a common, natural disturbance in the western U.S forests and grasslands and many other parts...
Tools woodland owners need to measure property acreage, boundaries, and characteristics of standing timber, including individual log volumes, are described.
Silvicultural canopy gaps are emerging as an alternative management tool to accelerate development of complex forest structure in young, even-aged forests of the Pacific Northwest. I investigated patterns of nitrogen (N) availability along transects through 0.1 and 0.4 ha silvicultural gaps in three 50-70 year old Douglas-fir forests of western...
The performance of pull factors for total retail sales in Oregon's
nonmetropolitan counties during the economic cycle of boom, bust, and recovery
of the early 1980s is examined for geographic patterns. One regional pattern and
several county patterns are identified and discussed. Counties having the highest
and lowest pull factors,...
We studied genetic polymorphism and phylogeny using nuclear random amplified polymorphic DNA markers (RAPDs) and mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) in the three California Closed-Cone Pines: Pinus attenuata Lemm., P. muricata D. Don, and P. radiata D. Don. A total of 343 to 384 trees derived from...
Tree species directly and indirectly affect soil nutrient cycles. I sought to characterize soils and foliage associated with four common canopy tree species (Douglas-fir, western hemlock, western redcedar, and bigleaf maple) in mixed-species old-growth forests of the Oregon Coast Range and to determine whether and how soils differ among the...
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Steven S. Perakis
Tree species directly and indirectly affect soil nutrient cycles. I
Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals’ ability to thrive in the altered, often simplified, structure of the postfire environment. The extent of fire...
Phylogeographic studies of six Pacific Northwest forest-associated
salamanders provide insight into historical and contemporary processes on
population genetic structure. Among Larch Mountain Salamanders (Plethodon
larselli), cytochrome b mitochondrial (mtDNA) sequences (381 bp) and random
amplified polymorphic DNA (RAPDs; 34 loci) supported separate Management
Units for northern and southern populations (12...
Since the passage of the mining and mineral leasing
laws, a considerable amount of the public domain has been
excluded from mineral exploration and development. It has been
estimated that as much as fifty-three and sixty-four percent
of the public lands have been withdrawn from the jurisdiction
of the mining...
Water temperature is an essential property of a stream. Temperature regulates
physical and biochemical processes in aquatic habitats. Various factors related to
climatic conditions, landscape characteristics, and channel structure directly influence
stream temperature. Numerous studies indicate that increased average air temperature
during the past century has led to stream warming...
Material testing experiments are needed to enable the next generation of nuclear fission reactors. Concluding in 2009, the Boosted Fast Flux Loop (BFFL) project was devised as a way to test fast reactor materials and fuels in the Advanced Test Reactor (ATR), however the experiment location it used is now...
Equations for predicting height from diameter outside bark at breast height (DBH) were generated for 24 tree species in western Oregon. The equations were based on the asymptotic Chapman-Richards function. Because geographic location and site productivity may influence height-diameter relationships, height-diameter measures from 8727 plots were first grouped by site...
Fire history and fire regime were interpreted from tree ring analysis of 4320 stumps at 178 sites in a 25 by 55 km area in the central Oregon Coast Range. A total of 27 fire episodes were identified in a 516 year period, with sizes estimated at 18 to 544...
The effects of fire severity on post-fire succession and shrub demography were quantified in shrub-steppe grasslands and subalpine forests in the Hells Canyon of the Payette National Forest, Idaho. Following the 1988 Eagle Bar Fire, species frequency, community diversity, fire adaptations, and stand ages were quantified at 12 plots in...
This annotated bibliography was compiled to provide a comprehensive list of sources on the ecological factors that affect forest regeneration. Abstracts from 494 publications are indexed by author, species, and subject, and are arranged into 4 major sections. Topics include the effects of biotic factors, abiotic factors, and stand and...
Disturbance, whether natural or of human origin, modifies to varying degrees
many ecosystem attributes. Fire is a natural process in the montane forests of southern
Oregon but for much of the 20th century fire was viewed as an apocalypse and thus
fervently suppressed. Effective natural resource management requires an
understanding...
The contribution of delayed adaptive reiteration to crown maintenance was explored across a wide range of adjacent open space conditions in early-mature (approximately 60 year old) Douglas-fir located on the eastern slope of Oregon’s Coast Range. The stands had experienced uniform thinning in 1964-65 and 1980-81 to release dominant and...
Rats exposed to one or two doses of 60 mg mirex/kg
by gavage exhibited hypertrophied livers and various
degrees of hepatobiliary dysfunction. Although single
dosed animals demonstrated elevated whole liver bile flow
after 96 hours, the single dose was insufficient to
significantly inhibit whole liver hepatobiliary
performance as measured by...