Early in the planning of the Coniferous Biome program It was recognized that experimental watersheds 2 and 3 in the H. J. Andrews Experimental Forest might provide ideal study sites for certain phases of the Biome
program. A study was funded during year 1 (1970) to provide necessary background ecological...
Early in the planning of the Coniferous Biome research program, it was recognized that Experimental Watersheds 6, 7, and 8 in the
H. J. Andrews Experimental Forest might provide ideal study sites for certain phases of the Biome program. A study was funded during year 1 (1970) to provide necessary...
The Normalized Burn Ratio and Composite Burn Index were used to classify burn severity in three sites that experienced lightning-ignited wildfire in the year 2000. The effect of burn severity (unburned, low, moderate, and high severity classes) was investigated on vegetation and soil microbial community composition. Vegetation communities showed a...
Measurement of plant moisture stress of 1-2 m understory conifers
was made in "reference stands" on the H. J. Andrews Experimental
Forest in 1970-1972. Maximum stress each year (measured between midnight
and dawn) is closely correlated with the position of each community
along one axis of an ordination of the...
The objective of this study was to examine the variation among ammonia-oxidizing and denitrifying communities in soils of a natural Fennoscandian boreal forest and of a forest with a long history of fertilization with different levels of nitrogen (N), and to examine whether there are any changes in the microbial...
Air temperatures at i m and soil temperatures at 2C cm are reported for
twenty-one forest stands in the central Western Cascader of Oregon. Records
began in 1970 for some stands, in 1971 or 1972 for most. Temperature Growth
Index for a stand, based on temperature effects on Douglas-fir seedling...
The over-arching theme of this work is that soil data affect the performance and realism of vegetation models with particular focus on their ability to predict or explain disturbances such as fire or disease. We tested the sensitivity of the Excel version of the 3-PG model to soil properties and...
The optimum goal of forest management is to foster long-term productivity and ecological integrity while maintaining or increasing short-term growth and yield through sustainable practices. Understory vegetation plays a definite role in forest functions through nutrient cycling and habitat provisions. The objective of this study was to determine how salal,...
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...
In intensively managed forest plantations in the northern Oregon Coast Range, herbicides are often applied during site preparation and early stand regeneration to reduce competition for resources for planted conifer seedlings. In addition to reducing competition for crop trees, herbicide applications may affect soil processes including decomposition and nutrient cycling,...
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Chapter 2: Effects of Intensive Forest Management and Wildlife on Decomposition and Soil
Soils are the largest terrestrial pool of carbon, therefore it is critical to understand
what controls soil carbon efflux to the atmosphere in light of current climate uncertainty.
The primary efflux of carbon from soil is soil respiration which is typically categorized
into autotrophic and heterotrophic respiration. These two components...
The objectives of this thesis were to examine the links between soil microbial community composition and function using the nitrogen (N) cycle as a model for these interactions and to assess the impact of environmental factors such as microclimate, vegetation type, and nutrient availability on microbial diversity and N transformations...
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...
The increased demand for wood and fiber from a continually shrinking land base has resulted in the use of intensively managed forest plantations. The concentration of timber production on the most suitable sites allows the world's demand for forest products to be met on less land and enable native forests...
The abundance and spatial heterogeneity of coarse woody debris (CWD) on the forest floor is a prominent feature of Pacific Northwest (PNW) forest ecosystems. The effect of CWD on soil solution chemistry, nutrient cycling and availability, soil physical structure and formation of soil organic matter, however, remains unknown. Therefore, studies...
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...
This study evaluated the effects of a crawler tractor, a rubber-tired skidder, and a torsion suspension vehicle on several soil and hydrologic properties in the western Sierra Nevada Mountains of California. Four sites, with soil textural classes ranging from a loam to a loamy sand and elevations between 680 and...
Miombo woodland and dambo grassland soils were selected to study the effect of soil transfer on early growth of B. petersiana, C. spectabilis, and C. calothyrsus on degraded sites in northern Zambia. The experiment was conducted on previously slash and burned, cultivated, and abandoned sites. Both sterile and unsterile miombo...
Ectomycorrhizal fungi (EmF) form symbioses with trees. These symbioses profoundly influence forest ecology. Certain EmF form specialized profusions of hyphae, known as ectomycorrhizal fungal mats (mats) which are visible to the naked eye, alter forest soil biogeochemistry, substantially contribute to soil microbial biomass/respiration and support unique microbial communities. Piloderma and...
Rainfall, discharge, traffic, and suspended sediment
were monitored for a period of 4.5 months at three
locations on a secondary haul road at Polk Inlet, Alaska to
determine the important processes and variables involved in
surface road erosion for this area. Three sites all less
than 500m² and within 5...
Emissions largely associated with the combustion of fossil fuels and agriculture has caused elevated atmospheric deposition of nitrogen (N) and sulfur (S) throughout much of the developed world. Increased atmospheric deposition of N and S can lead to soil and surface water acidification and affect forest soil nutrient supply. The...
Humus is one of the important factors controlling the soil
formation process. The nutrients released from it during the decomposition
process also affect the growth and reproduction of the
forest. The type of humus formed is influenced by the nature of the
forest litter and the environment in which it...
Field reconnaissance, soil sampling, and laboratory analyses were
conducted to characterize the soils of the 50 by 50 meter forest community
reference stand plots in and near the H. J. Andrews Experimental
Forest. Soil descriptions, chemical and physical properties, soil classification,
and nutrient capital information for mineral soils are summarized....
Findley Lake watershed is located in the Snoqualmie National Forest and has a surface area of 259 ha (1 Mi²). The lake is at an elevation of 1128 m (3701 ft) but the ridges attain elevations of 1450 m (4750 ft).
The Cougar Mountain Formation, consisting of lava flows, conglomerate,...
The relationship between annual foliage production and nitrogen and water stress was examined in 14 naturally regenerated, mid-rotation ponderosa pine stands in central Oregon. Current-year and older foliage masses, and foliage nitrogen contents and concentration were estimated from 132 destructively sampled trees. Litterfall mass and nitrogen retranslocation rates from senescing...
This is the annual report from the investigators responsible for soil
characterization at the Findley Lake watershed. Soil characterization
is complete for two soils and is in progress on six others. Site
preparation for years 3 and 4 is complete except for lysimeter
installation.
Goals in 1972 included characterization of the soils of the
Oregon IBP reference stands, development of information on the soils
throughout the H. J. Andrews Experimental Forest, and evaluation
of nutrient provision to the major kinds of soils. Field reconnaissance,
soil morphology studies, and sampling were carried out.
Lab analyses...
This study was undertaken to determine both the amount and the
spatial variability of sand, silt, clay, and six fractions of coarse
fragments in soils representing harsh sites for reforestation. Particle size data were collected because of their direct relationship to
water holding capacity and the plantability and survivability of...
Management practices following forest harvest can affect long-term soil productivity through alteration of soil carbon (C) and nitrogen (N) pools, but processes contributing to change are poorly understood. I assessed effects of three levels of logging-debris retention in combination with initial or annual applications of competing vegetation control (CVC) following...
Measurements for water retention calculations and physical
characterization were made on skeletal and non-skeletal soils in
southwest Oregon. A new bulk density sampler was designed for the
physical characterization of the steep, skeletal soils commonly
encountered in this area. The new sampler and the techniques
required for the measurement and...
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...
Published January 1991. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published July 1983. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Soil compaction can happen whenever machinery, livestock, or people
travel on the land. On woodlands, compaction is most likely to be
caused by logging equipment such as crawler tractors and rubbertired skidders.
Revised November 1990. Reprinted March 1998. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
The use of mechanized harvest equipment has been
increasing as an economical method to harvest small diameter
timber. While the use of this equipment is increasing,
little is known about associated soil compaction. In
particular, little information exists on soil compaction
caused by feller--bunchers.
This study measured soil compaction caused...
Monitoring soil density on three sites during repeated trips with a high-speed skidder showed that: During the first 20 trips, soil density primarily increased between depths of 2 to 4 inches; Density increased most during the first few trips; Density continued to increase slowly in amount and depth with the...
Soil organic carbon (SOC, kg C m-2) is an important component in evaluating global C stores. The nitrogen (TN, kg N m"2) cycle is closely linked to C and understanding its role is also important. Contents and distributions of SOC and TN in soil profiles, to 1-meter depth, were estimated...
Despite the recognized role of soil arthropod fauna on nutrient cycling
and decomposition processes, many aspects of the effects of sylvicultural
methods in forest ecosystems upon their biology remain poorly understood.
The long term effects of prescribed fires on soil arthropods in forest
ecosystems in the Pacific Northwest have never...
The work upon which this publication is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964 and by the United States Department of Agriculture, Forest Service, Pacific Northwest Forest...
In 1957 three Douglas-fir stands (15-, 25-, and 40-year-old age classes) were selected on a tree farm in the Cascade foothills of
northwestern Oregon to study factors affecting site productivity. Soil-moisture, soil-temperature and seasonal radial- growth pattern measurements were made with a Colman moisture meter and a dial gauge dendrometer...