Over the last decade a new perspective on how forest ecosystems operate has emerged. Ecosystems appear much more flexible than we once thought. Even the most persistent is still evolving in composition. Yet for all their diversity, very similar processes are seen as operating in all forests, providing a point...
Although there has been extensive research on the geomorphic and ecologic role of
large woody debris (LWD) in streams, the dynamics of LWD in streams are poorly
known due to various measurement difficulties during floods. In this thesis I present the
results of two flume experiments on the dynamics of...
Respiratory rates were measured, in situ, for the litter, the
soil, and the litter-soil subsystems of a Pseudotsuga menziesii forest
as a function of type of understory vegetation. The major objectives
were to demonstrate the utility of the litter layer as a distinct subsystem
of this forest ecosystem, to demonstrate...
Numerous isolates of Armillaria mellea were obtained within
a 250 by 450 foot Study Area in a ponderosa pine plantation in central
Oregon. These isolates were recovered from roots of armillaria-killed
young-growth pine, from large stumps of the former pine
overstory, including roots away from the stump proper, and from...
The initial distribution of organic arsenical silvicides was
measured in the trees, litter and soil of four forest types in the
Pacific Northwest following a standard, precommercial chemical
thinnning. Factors which influenced the persistence, movement or
fate of these compounds were noted and used to evaluate differences
in the generalized...
Riparian communities in the southern portion of Malheur National
Forest were intensively studied with the objective of designing an approach for
classifying disturbed riparian areas into units of similar potential. Not all
riparian community types in this portion of the Blue Mountains were sampled
due to time limitations. Some of...
Despite the critical ecological roles of structural features in forests, ecologically
relevant quantitative measures of structure that allow comparisons among forest stands
are still limited. A new index, the structural complexity index (SCI), was developed to
characterize and compare the structural complexity of different forests. Point patterns
of stem-mapped trees...
Riparian zones are ecotones between terrestrial and aquatic ecosystems. Processes in streams are strongly influenced by riparian forest communities, age, stage and structure. Temperate forests across much of North America, including riparian areas, are recovering from historic land clearing with many stands in the stem-exclusion phase of development in which...
This study has been concerned with the patterns of vegetative changes which occur during the first five years following logging and burning on Douglas-fir clear cuts. Knowledge of the successional sequence in the coastal forests of western Oregon is of primary importance to those concerned with the management of this...
A study was undertaken in the Marys Peak watershed with the
following objectives. First, a classification of the major plant communities
was carried out. Second, some of the ecological features
of Acer circinatum that account for its distribution within these
communities were determined. The following plant communities
are described:
Corylus...
Seven sites of uniform topography and soil were selected within
a self perpetuating ponderosa pine forest found on the eastern
flank of the central Oregon Cascades. These plots were located along
a vegetational gradient caused mainly by an orographic rain shadow.
Data gathered included density, frequency, and cover for all...
The overall goal of this study was to investigate influences of ectomycorrhizae (EM) and
interspecific carbon transfer on seedling performance in species mixtures. The objectives were to:
(I) determine the potential for EM to link paper birch and Douglas-fir, (ii) quantify gross and net
interspecific carbon transfer, and (iii) evaluate...
Nitrogen, phosphorus and sulfur concentrations were measured in the soil, foliage and litter of Douglas-fir growing in pure Douglas-fir and mixed conifer stands. On four sites of contrasting fertility and climatic conditions, plots had been modified by the introduction of alder, thinning, or by a single application of nitrogen fertilizer...
Pacific madrone, tanoak, and California black oak are the most economically promising native California hardwoods. Volume and value data indicate upward trends in growing stock levels and prices received for their products. These trends are likely to continue. They suggest research is particularly needed for: (1) seed fall and
regeneration,...
A greenhouse bioassay was used to investigate effects of natural and manmade disturbances on native ectomycorrhizal populations of Douglas-fir and western hemlock on a steep southeast slope in the
west central Cascade Mountains. Total and mycorrhizal root tips were counted on seedlings grown in soils collected from (a) two 100+...
Samples of mature vegetation from 8 of 12 major vegetational zones in Oregon and Washington, representing about 80% of the area of the two states, were studied along a latitudinal transect from the Pacific Coast
to the east slopes of the Cascade Mountains. Six stands were in forest zones, one...
The ecological and silvicultural importance of snowbrush,
Ceanothus velutinus, in the areas west of the summit of the Oregon
Cascades was studied. Particular attention has been given its nitrogen-
fixing ability under both field and greenhouse conditions.
On west slopes of the Oregon Cascades snowbrush occurs above
2, 500 feet...
Several understory conununities display successional stages during the first two hundred years following logging or fire disturbance in the coastal Picea-Tsua forests of southeast Alaska. Residual shrubs
and tree seedlings increase their growth exponentially after overstory removal. Understory biomass peaks at about 5000 kghayr fifteen to twenty-five years after logging....
Fire history and fire regimes were reconstructed for a 450 km² area in the central
western Oregon Cascades, using tree-ring analysis of fire scars and tree origin years at
137 sampled clearcuts. I described temporal patterns of fire frequency, severity, and size,
and interpreted topographic influences on fire frequency and...
Riparian areas that can be used as reference sites on which to base goals of vegetation restoration have not been documented in the Oregon Coast Range. I examined the composition and distribution of unmanaged riparian overstories in the central Oregon Coast Range along nine streams which have experienced minimal disturbance...
A study of the McKenzie River floodplains, terraces and glacial
outwash plains was undertaken to classify and describe the vegetation
and soils of a previously little studied synecological unit.
During the summer of 1971, 54 analytic vegetation and soil
plots (stands) were studied. Cover and frequency of all trees, shrubs,...
Total length and biomass of fungal mycelium in the soil of a young Douglas-fir stand in the central Oregon Coast Range were estimated over 27 months with the agar-film technique. In a second study, phenology and taxonomy of hypogeous (belowground) sporocarps were studied over 32 months in a nearby, young...
A three-year investigation was conducted during 1980-1982 to
evaluate the potential of using herded sheep as a silvicultural tool
to suppress brush in Douglas-fir (Pseudotsuga menziesii) plantations
of Oregon's Coast Range. Sheep browsing of Douglas-fir was highest
in May soon after bud break. Averaged over the 2 years of grazing,...
Nutrient and particulate matter balances were established for five ecosystems dominated by Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in the western Cascades, Oregon. Carriers of N and P were particulate matter (dust in precipitation and sediment in streams) and dissolved matter in both precipitation and stream water. The input and outflow...
Tree seedling establishment and growth were studied in experimental canopy gaps to determine the effect of structural and environmental heterogeneity on species dynamics within mature and old-growth Douglas-fir forests in the Cascades of central Oregon and southern Washington. Factors examined included forest age, gap size, within-gap position. substrate, year of...
The characteristics and interactions of the riparian
stand, large woody debris (LWD), and channel morphology
were examined on five undisturbed, low gradient streams in
southeast Alaska. One first-, two second-, one third-,
and one fourth-order streams were studied. Stream
morphology variables were measured systematically at fixed
intervals of three to...
Forest associations, secondary succession, and relationships
of plant communities to Roosevelt elk were investigated. Stratification
of vegetation into ecological units and an understanding of secondary
succession by habitat-type were a necessary first step in investigations
into browsing of conifers by elk. The study was jointly conducted
by the Oregon State...
Much of the native riparian vegetation of the Willamette Valley, Oregon, has been replaced with agricultural crops or invasive non-native plant species. Detailed information about current Willamette Valley riparian vegetation is generally lacking. Plant specie composition data are useful in a variety of applications, including condition assessment, environmental monitoring and...
We evaluated the regeneration behavior and early growth rates of 10 non-pioneer canopy tree species in medium-height, semi-evergreen dry tropical forest in Quintana Roo, Mexico. These species provide timber and non-timber forest products for local communities and include evergreen and deciduous species with varied dispersal mechanisms. The species were Coccoloba...
Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has...
Large woody debris recruitment to streams from adjacent riparian forests influences stream
channel morphology, sediment routing, and fish habitat. A mathematical model was developed
to 1) determine whether the trees in a stand adjacent to a stream, upon falling, would provide
large woody debris of a specified size to the...
A study was initiated in 1961 to characterize seral plant
communities in a part of the Cedar Creek drainage in the Tillamook
Burn. Stratification of vegetation into ecological units was a necessary
first step in conifer-animal damage studies supported by the
Oregon State Game Commission.
Reconnaissance information was recorded in...
Species richness and abundance of forest floor bryophytes, including epiphytes from incorporated litterfall, were assessed at two sites in western Oregon. Bryophyte diversity, abundance, and community composition were compared between sites, and between young forest stands ([approximately] 55 yrs.) and old-growth stands (400+ yrs.) within each site. Relationships of stand...
The tree species and size structure of 9l old-growth forests dominated by Douglas-fir
in central western Oregon was characterized using complete inventories of all trees larger than 20cm dbh over a mean area of 17.1ha at each site. Douglas-fir accounted
for over 75% of the total average basal area (39.1...
Riparian forests in the central Oregon Coast Range vary along a coniferous-deciduous compositional continuum. Variations in structure and composition affect water quality, fish and wildlife, biodiversity, timber, and aesthetics. A retrospective approach was taken in this study in order to understand and compare the structure, pattern, and history of an...
We sampled vegetation, bryophytes, lichens, environment, and stand dynamics in 56 plots in the Swan Valley, Montana in 1975-1978. The data include complete inventory of trees in 375 m2 plots, with whole-plot ocular estimates of plant cover by species, transect sampling of the ground layer bryophytes and lichens with microplots,...
Large fallen trees in various stages of decay contribute much-needed diversity of ecological processes to terrestrial, aquatic, estuarine, coastal beach, and open ocean habitats in the Pacific Northwest. Intensive utilization and management can deprive these habitats of large fallen trees. The publication presents sound information for managers making resource management...
Twelve sites of uniform topography and soils were selected in
the Pinus ponderosa/Purshia tridentata/Festuca idahoensis Association.
These sites were located in the rain shadow on the east flank
of the Oregon Cascades. A fire history in the form of fire scars on
ponderosa pine was available for nine of these...
The early stages of secondary succession of the
McDonald and Paul Dunn State Forests, Corvallis, Oregon,
were grouped into three stages; herb, herb-shrub, and
shrub, based on vegetation types. Flowers of herbaceous
species and residual shrubs dominated in the early years
after clear-cutting. Woody plants became increasing
abundant in the...
A biological inventory of the butterflies of the H. J. Andrews Experimental Forest [HJA] in Linn/Lane County, Oregon was conducted during 1994 and 1995. It was the first comprehensive survey of HJA butterflies for the site and serves as a baseline for future butterfly research. A detailed ecological account is...
The juvenile development of Douglas-fir, red alder and snowbrush
associations was investigated in western Oregon. The relationship
between Douglas-fir and red alder was studied and compared
in the Coast, Willamette Valley and Cascade regions. Snowbrush-
Douglas-fir stands were sampled in the western Cascades. Alder-
Douglas-fir relationships were studied on clearcuts...
I studied spring food habits, focusing on cambium-feeding, of black bears (Ui-gus americanus) in the Central Coast Ranges of Oregon (1987-90) by comparing an area with high levels of timber damage caused by bears (north area) with an adjacent area of low levels of bear damage (south area). I also...
Coarse woody debris (CWD) decomposition in the Russian boreal forests of the southern taiga zone was studied at four sites located near St. Petersburg in Northwestern Russia, Krasnoyarsk in Eastern Siberia, lrkutsk in the Baikal region, and Khabarovsk in the Russian Far East. This study was part of a broader...
A crossdated fire history was reconstructed for a 1562 km2 area in the southern Willamette foothills of Oregon, using fire scars and tree origin years from twelve sites. The purpose of this study was to determine fire frequency for each site and to quantify temporal and spatial variability of fire...
The growth of Alnus acuminata (HBK) 0. Ktze, Cupressus
lusitanica Mill., Gmelina arborea Roxb, Pinus caribaea var. hondurensis
Barr. & Golf., and Tectona grandis L. in Costa Rica and
twenty seven soil and climatic factors were analyzed to determine
the relationship between major environmental factors and growth
rates of these...
Tropical forests are of global importance with respect to their influence on
biogeochemical cycles, climatic patterns, and as large reservoirs of biodiversity. Yet, few studies have quantified their structure, biomass, and carbon pools; basic
information necessary to better understand the global function of tropical forests. The RADAMBRASIL project was conducted...
This volume results from an experiment in data retrieval. During the initial stage of the Coniferous Forest Biome the authors were asked to provide access to the literature on mammals as it pertained to the interests of the Biome investigation. One constraint was that the total number of entries should...
The "old-growth controversy" in the Pacific Northwest recognized thinning as the
primary silvicultural practice for land managers to produce wildlife habitat while
continuing to produce timber. For the foreseeable future, forest stands will be harvested to
produce forest gaps and a patchwork of trees of different ages. In order to...
In this study, biological and chemical characteristics were determined for two high-elevation meadow-to-forest transitions located in the Central Oregon Cascades. The chloroform fumigation incubation method (CFIM) was used to determine microbial biomass C(MBC) and the N flush due to fumigation (NF), and meadow values were compared to forest values for...
Analysis of the long-term spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon provides numerous ecological insights. Natural and anthropogenic disturbances have contributed to the development of a patchy mosaic of vegetation types in the area. Some hardwood patches in the Coast Range may be the...
I studied riparian forests of four western Oregon watersheds (dry south to wet north) to determine the multiscale controls on woody riparian vegetation. I conducted separate analyses of controls on plant distribution, diversity, and tree regeneration using vegetation and environmental data collected in two related field studies: (1) a multiscale...
This study examined the effect of fire regime on coarse woody debris (CWD) mass using a combination of field data and modeling. The objectives were to use field sampling to determine how CWD differs between two areas that have had different fire regimes, and investigate how fire frequency and severity,...
To effectively manage for biodiversity at broad, ecosystem scales, the influences of habitat structure at multiple spatial scales on vertebrate species must be understood. There are few studies on the broad-scale habitat requirements of stream amphibians despite their importance in streams in forest ecosystems in the Pacific Northwest (PNW) as...
"During the four meetings of the consumer modeling committee, discussion centered on the formation of systems models and the
problems they will pose for researchers concerned with consumer populations. Two coarse models were developed from these discussions, a compartment model (Figure 1) and a process model (Figure 2). The
compartments...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
This volume is a proceeding of the papers presented in an "Informal Conference" during the Annual Meetings of the Entomological Society of America held on December 8, 1985, in Hollywood, Florida. Although most of the papers presented during the conference are included in this publication, there were three additional papers...
This study compared effects of human and natural wildfire disturbance on age class distribution and associated ecosystem properties of forests in a 15,670 km2 area of the western Cascades of Oregon. The study site is characterized by three forest use types: low elevation, intensively harvested private industrial lands; mid elevation...
Trees that survive disturbances can form a prominent legacy which may influence
post-disturbance successional pathways. The effects of biological legacies on community
dynamics is a critical question in ecology. In the present study, I examined two mapped
stands in which old-growth remnant trees, survivors of partial fires, emerge above a...
Giant chinquapin (Chrysolepis chrysophylla) is an evergreen hardwood often found as a shrubby understory component of coniferous forests in the Pacific Northwest United States. Due to its ability to sprout quickly after disturbances such as fire and logging it is often viewed as a pest by forest managers. Like its...
Soil effects from mountain beaver (Aplodontia rufa ) burrowing were
investigated in Oregon Coast Range soils formed from Tyee sandstone. The potential
for observed changes in soil to affect productivity was assessed. Soil horizons from
mountain beaver mound soil and adjacent unmounded profiles were collected with a
monolith-type quantitative sampler....
From the 1920's through 1951 several severe fires occurred in the predominantly conifer forest ecosystems of the northern Oregon Coast Range. Of the 211,151 ha. of mapped area, 57 percent was burned. The effects of frequent fires with high severity on forest ecosystems over time at the landscape level is...
This study was conducted to describe variation of riparian vegetation in an Oregon Coast Range system according to geomorphic characteristics and in relation to streamflow. Specific objectives of this study were to: I) examine if the vegetation composition and structure of the riparian forest varied among channel-reach morphologies, 2) examine...
Forest stands were studied to determine if old-growth
forest structure could be mimicked in younger stands via
overstory manipulation. Cover and species composition of
understory plants were systematically sampled in sixteen
thinned second-growth stands and sixteen adjacent unthinned
second-growth Douglas fir (Pseudotsuga menziesii (Mirabel)
Franco.) stands. The stands were thinned...
The specific objectives of the program are: (1) To understand the relative behavior of terrestrial and aquatic ecosystems in various environments in the biome. (2) To develop conceptual and computer simulation models that describe nutrient, carbon, and waterflows on a short-term basis (fewer than ten years) and which integrate research...
The role of insect herbivores in the nutrient cycling dynamics of forest ecosystems remains poorly understood. Although past research in herbivory has focused primarily on the deleterious effects that insects can have on tree growth and mortality, the overall effects of herbivory are more complex. Herbivores have the potential to...
This symposium was arranged and conducted in cooperation with the Research and Products Committee of the National Lumber Manufacturers Association, 1319 Eighteenth St., N.W., Washington 6, D.C. The purpose was to bring together a group of approximately 100 individuals broadly representing various phases of the wood industry, the present wood...
Downed wood and antelope bitterbrush (Purshia tridentata) are often managed on federal ponderosa pine (Pinus ponderosa) forests in central Oregon to prevent catastrophic wildfires and provide wildlife habitat. However, although much is known regarding the roles of downed wood and bitterbrush in wildfire behavior, little is known regarding the relationships...