Mortality patterns in an old-growth, mixed-conifer forest, in the absence of wildfire, were investigated at the Teakettle Experimental Forest from 2000 to 2002. We tested the hypothesis that after a century of fire suppression, pathogen- and insect-associated mortality (between episodic droughts) would be significantly greater on ingrowth trees (i.e., smaller-diameter,...
In this study we analyzed the spatial
structure of ectomycorrhizal fungi present in the soils
as resistant propagules (e.g. spores or sclerotia) in
a mixed-conifer forest in the Sierra Nevada, California.
Soils were collected under old-growth Abies spp.
stands across approximately 1 km and bioassayed with
seedlings of hosts that...
The effect of disturbance on the resistant propagule community (RPC) of ectomycorrhizal
fungi has been given relatively little attention. In this study we investigate the effects of
heat, one important factor of fire disturbances, on the ability of ectomycorrhizal RPC fungi
to colonize Pinus jeffreyi seedlings in greenhouse bioassays. Prior...
The diets of a fungal specialist, northern flying squirrel (Glaucomys sabrinus (Shaw, 1801)), and a dietary generalist,
lodgepole chipmunk (Neotamias speciosus (Merriam, 1890)), were examined in the old-growth, mixed-conifer forest
at the Teakettle Experimental Forest in California’s southern Sierra Nevada. Spores of fungi were identified from fecal
pellets collected from...
The purpose of this study was to estimate the portion of an ectomycorrhizal (ECM) fungi root
community with a hypogeous fruiting habit. We used molecular methods (DNA sequence analysis of the
internally transcribed spacer [ITS] region of rDNA) to compare three viewpoints: ECM fungi on the roots in a
southern...
Prescribed burning and mechanical thinning are used to manage fuels within many western North American forest ecosystems, but few studies have examined the relative impacts of these treatments on forest wildlife. We sampled northern flying squirrels (Glaucomys sabrinus) and microhabitat variables in burned, thinned and control stands of mixed-conifer forest...
We examined the nest-tree preferences of northern flying squirrels (Glaucomys sabrinus) in an old-growth,
mixed-conifer and red fir (Abies magnifica) forest of the southern Sierra Nevada of California. We tracked 27
individuals to 122 nest trees during 3 summers. Flying squirrels selected nest trees that were larger in diameter
and...
In many western North American forests, prescribed burning and mechanical thinning are widely used to reduce
fuels and restore stand conditions after a century of fire suppression. Few studies have followed the relative impacts
of these treatments on the production and consumption of truffles in forest ecosystems, particularly in the...
We compared the abundance, diversity, and composition of truffles in riparian and upland areas within a
mixed-conifer forest of the Sierra Nevada of California. We sampled for truffles in a single watershed over two seasons
(spring and summer) and 4 years to determine whether truffles were more abundant and diverse...
Little is known about biophysical controls on soil respiration in California’s Sierra Nevada oldgrowth, mixed-conifer forests. Using portable and automated soil respiration sampling units, we measured soil respiration rate (SRR) in three dominant patch types: closed canopy (CC), ceanothus-dominated patches (CECO), and open canopy (OC). SRR varied significantly among the...
Frankia strains symbiotic with Ceanothus present an interesting opportunity to study the patterns and causes of Frankia diversity and distribution within a particular host infectivity group. We intensively sampled Frankia from nodules on Ceanothus plants along an elevational gradient in the southern Sierra Nevada of California, and we also collected...
In nature, chicks hatch after 2 to 4 weeks of incubation by the parents, most often the hen. The hatched chicks provide the stimulus to the hen to change her work from incubating eggs to brooding young. This form of brooding chicks is the easiest if only a few chicks...
The first decision to be made is whether to incubate eggs naturally or artificially. Natural incubation uses a broody hen to incubate eggs by sitting on them in a nest. Broody hens, when available, work best for small clutches of eggs.
Blue mustard (Chorispora tenella) is a native of Russia or
southwest Asia. It first was documented in this country in
Lewiston, Idaho in 1929, and has spread throughout the
western plains states, the western portion of the United States,
and southern Canada.
At a spatially heterogeneous mixed-conifer forest in the central California Sierras, we quantified total
carbon (C) and nitrogen (N), inorganic N, and net N mineralization in organic (O) and surface (0–15 cm) mineral
soils, and in situ fluxes of inorganic N and ortho-phosphate using resin lysimeters under three patch types:...
To understand the roles of forest management
practices in meeting the goals of forest sustainability and CO2
sequestration, we evaluated the effects of burning and thinning
treatments on soil respiration and soil environments in an
old-growth, mixed-conifer forest in California’s southern Sierra
Nevada. Six experimental treatments with two levels of...
The effects of management on soil carbon efflux in different ecosystems are still largely unknown yet crucial to both our understanding and management of global carbon flux. To compare the effects of common forest management practices on soil carbon cycling, we measured soil respiration rate (SRR) in a mixed-conifer and...
We compared canopy arthropod assemblages among overstory conifer and understory angiosperm
species at Teakettle Experimental Forest in the Sierra Nevada in California during 1998–2000. Arthropods were
sampled from upper, middle, and lower crown levels of one overstory tree of each of the four dominant conifer
species (Jeffrey pine, sugar pine,...
Sierra Nevada forests have high understory species richness yet we do not know which site factors influence
herb and shrub distribution or abundance. We examined the understory of an old-growth mixed-conifer
Sierran forest and its distribution in relation to microsite conditions. The forest has high species richness
(98 species sampled),...
Mechanical thinning and prescribed fire are widely used to restore western forests after a century of fire suppression, yet we know little about how these treatments affect understory communities where plant diversity is highest. We followed understory plants and environmental factors in old-growth, Sierran mixed conifer for two pre-treatment and...
Forest-fire policy of U.S. federal agencies has evolved from the use of small
patrols in newly created National Parks to diverse policy initiatives and institutional arrangements
that affect millions of hectares of forests. Even with large expenditures and
substantial infrastructure dedicated to fire suppression, the annual area burned by wildfire...
We determined the incidence of pathogens and insects across mixed-conifer stands in the Sierra San Pedro
Martir (SSPM) of northern Baja, Mexico, to assess the role of pests in a pristine forest ecosystem. We also determined
the spatial distribution of the two most common pests, mistletoe, Phoradendron pauciflorum Torrey, and...
The enlargement of 21 canopy gaps associated with the root pathogen Heterobasidion annosum (Fr.:Fr.)
Bref. (; Fomes annosus (Fr.) Karst.) in the mixed-conifer forest of Yosemite Valley was monitored between 1971 and
1998. Mean expanded gap area was 232 m2 (range 38–802 m2) in 1971 and 1455 m2 (range 150–4216...
Most administrators and ecologists agree that reducing the levels of hazardous fuels on forests is essential to restore healthy
watersheds and protect adjacent human communities. The current debate over the appropriateness, technique, and timing of treatments
utilized to restore vegetation structure and composition is currently on-going at local, state, and...
Many indicators and criteria have been proposed to assess the sustainable management of
forests but their scientific validity remains uncertain. Because the effects of forest disturbances
(such as logging) are often specific to particular species, sites, landscapes, regions
and forest types, management ‘‘shortcuts’’ such as indicator species, focal species and...
Fire performs many beneficial ecosystem functions in dry forests and rangelands across much
of North America. In the last century, however, the role of fire has been dramatically altered by numerous
anthropogenic factors acting as root causes of the current fire crisis, including widespread logging, road
building, fire suppression, habitat...
The management of fire-prone forests is one of the most controversial natural resource issues in the US today,
particularly in the west of the country. Although vegetation and wildlife in these forests are adapted to fire, the
historical range of fire frequency and severity was huge. When fire regimes are...
We determined the spatial pattern of dwarf mistletoe (Arceuthobium
spp.) associated with two different conifer hosts, white fir (Abies
concolor) and Jeffrey pine (Pinus jeffreyi), in forests around the Lake
Tahoe Basin and at the Teakettle Experimental Forest, both located in the
Sierra Nevada. We also examined a number of...
The Teakettle Ecosystem Experiment in the southern Sierra Nevada is using thinning and prescribed
fire to recreate historical stand conditions. As part of Teakettle we assessed pretreatment diversity and density
of the soil arthropod community in 1998 and 2000. We determined the density and diversity of soil microarthropods
among treatment...
Forest managers have little information of the effects of common restoration treatments, thinning and burning, on dead woody material (DWM) dynamics in fire-suppressed forests. Fine woody debris (FWD; 0.6–29.9 cm), coarse woody debris (CWD; ≥30.0 cm), and snags (≥5 cm) were inventoried and mapped in eighteen 4 ha plots before...
In the Sierra Nevada, distributions of forest tree
species are largely controlled by the soil-moisture
balance. Changes in temperature or precipitation as
a result of increased greenhouse gas concentrations
could lead to changes in species distributions. In
addition, climatic change could increase the frequency
and severity of wildfires. We used...
Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early
stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is
relatively abundant even in old-growth forest conditions which are at least partly maintained by fire.We conducted
a field experiment...
Studies of the effects of climate change on forests have focused on the ability of species to tolerate temperature and moisture changes and to disperse, but they have ignored the effects of disturbances caused by climate change (e.g., Ojima et al. 1991). Yet modeling studies indicate the importance of climate...
Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and
anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer
forest on the western slope of the Sierra Nevada Mountains....
Understanding the relative influence of fuels and climate on wildfires across the Rocky Mountains is necessary to predict how fires may respond to a changing climate and to define effective fuel management approaches to controlling wildfire in this increasingly populated region. The idea that decades of fire suppression have promoted...
Western United States forest wildfire activity is widely thought to have increased in recent decades,
yet neither the extent of recent changes nor the degree to which climate may be driving regional
changes in wildfire has been systematically documented. Much of the public and scientific
discussion of changes in western...
Climate warming may first show up in forests as increased growth, which occurs as warmer temperatures, increased carbon dioxide, and more precipitation encourage higher rates of photosynthesis. The second way that climate change may show up in forests is through changes in disturbance regimes—the long-term patterns of fire, drought, insects,...
Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the structure and function of these ecosystems and their response to widely used restoration treatments. Collectively the studies found fire was essential...
Successful fire exclusion in the 20th century has created severe fire problems across the West. Not every forest is at risk of
uncharacteristically severe wildfire, but drier forests are in need of active management to mitigate fire hazard. We summarize a
set of simple principles important to address in fuel...
Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures
that are vulnerable to catastrophic fire. This paper models fire behaviour in a mixed-conifer forest and investigates how
silvicultural and fuels treatments affect potential fire behaviour. The computer program FARSITE was used to spatially...
The term "forest health" is being increasingly used in the context of forestry and natural resource management. For example, the term has been the subject of several articles in the JOURNAL oF FORESTRY and a recent Society of American Foresters task force report, Sustaining Long- 7•rm Forest Health and Productivity...
During 1997–1998, we investigated the influence of both the relative abundance of truffles, preferred food
items, and microhabitat structure on the occurrence of northern flying squirrels (Glaucomys sabrinus Shaw) in oldgrowth
forest habitat of the Sierra Nevada Range, U.S.A. Following live-trapping sessions, we searched the forest floor
for truffle diggings...
In Sierra Nevada forests, shrubs are considered strong soil moisture competitors with regenerating trees, reducing seedling establishment, and
slowing growth. Recent studies, however, suggest that in some circumstances shrubs can facilitate tree establishment and growth by modifying
harsh microclimate conditions; increasing acquisition of water, carbon, and/or nutrients via shared mycorrhizal...
Revised November 1961. 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
Revised October 1969. 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
Revised June 1981. 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 January 1966. 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
Perennial ryegrass (Lolium perenne L.), also called English ryegrass, is a cool-season perennial bunchgrass native to Europe, temperate Asia, and North Africa. It is widely distributed throughout the world, including North and South America, Europe, New Zealand, and Australia.
Tall fescue (Festuca arundinacea Schreb.) is a perennial, cool-season bunchgrass that is grown for pasture, hay, and silage. Native to Europe and North Africa, it was introduced from Europe to North and South America.