Turbines at wind projects pose a threat to birds and bats flying at altitudes within the rotor swept area. These animals die from colliding with the turbine blades. Estimating mortality, or the total number of bird or bat fatalities at a wind project, is critical to understanding environmental impacts of...
We conducted capture and acoustic surveys for bats in six areas along a latitudinal gradient in Southeast Alaska from mid-May to September in 2005 and we continued surveys on Prince of Wales Island from mid-May to September in 2006. We determined the level of effort required to catch each species...
I examined factors regulating decomposition rates of red alder (Alnus rubra)) and Douglas-fir (Pseudotsuga menziesii) leaf litter in Coast Range riparian areas in western Oregon. Overall, this study was designed to examine the influence that leaf litter quality characteristics and decomposition site treatment have on decomposition rates, to provide a...
Thinning of young Douglas-fir forests has the potential to enhance structural diversity and improve habitat for wildlife. I examined the effects of thinning and thinning intensity on abundance and demographic characteristics of forest-floor small mammals in the Coast Range of Oregon 5 and 6 years after thinning had occurred. Thinning...
Shorebirds display great variation in mating systems and breed in dynamic environments that are increasingly subject to human threats worldwide. In order to adequately assess productivity and demography of shorebird populations, it is important to understand factors that influence patterns of parental care and reproductive success. The Black Oystercatcher (Haematopus...
Many wind-power facilities in the United States have established effective monitoring programs to determine turbine-caused fatality rates of birds and bats, but estimating the number of fatalities of rare species poses special difficulties. The loss of even small numbers of individuals may adversely affect fragile populations, but typically, few (if...
Lower order, non-fish-bearing streams, often termed ‘‘headwater streams’’, have received minimal
research effort and protection priority, especially in mesic forests where distinction between riparian
and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is
higher in riparian zones, little is known about species distributions...
To better understand the influence of competition on wood formation and wood quality in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), patterns of cambial growth and latewood production were examined for one growing season in 15-year-old plantations with similar densities but differing Douglas-fir/red alder (Alnus rubra Bong.) ratios. The treatments consisted of...
Studies examining the effects of human disturbance on avian parental behavior and reproductive
success are fundamental to bird conservation. However, many such studies fail to also consider the influence of
natural threats, a variable environment, and parental roles. Our work examines interactive relationships of cyclical
(time of day, tide, temperature,...
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors...
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, Oregon USA). LiDAR was collected approximately 2000 m
above ground level by a fixed wing aircraft
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors...
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Research Station, U.S. Forest Service,
Corvallis, OR 97331, USA
M. Huso
Forest and Rangeland Ecosystem
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors...
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Government Camp Station (NCDC COOP number 353402) is located at 45°18’N
121°145’W, 1213 m asl. The Mt Hood
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...
Many land managers in the Pacific Northwest have the goal of increasing late-successional forest structures. Despite the documented importance of Douglas-fir tree bark structure in forested ecosystems, little is known about factors influencing bark development and how foresters can manage development. This study investigated the relative importance of tree size,...
If arid sagebrush ecosystems lack resilience to disturbances or resistance to annual invasives, then alternative successional states
dominated by annual invasives, especially cheatgrass (Bromus tectorum L.), are likely after fuel treatments. We identified six
Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle & Young) locations (152–381 mm precipitation) that
we...
Despite their inherent importance and utility as ecological examples, island species are among the most endangered and least studied groups. Guam Micronesian Kingfishers (Halcyon cinnamomina cinnamomina) exemplify the plight of insular biota as a critically endangered and understudied island bird that went extinct in the wild before they could be...
Understanding how wetland birds use habitat is pivotal to developing successful and
beneficial conservation strategies. Although it has been an ardent topic in forest
research for some time, how species interact with the spatial patterning of habitat
across a landscape (i.e., landscape structure) has been more or less neglected in...
Avian movement behavior provides insight on patterns of regional and local fidelity, habitat and resource requirements, the scale at which individuals perceive the landscape, and the relative influence of the spatial array of resources. Shorebirds (suborder: Charadrii) are a diverse and mobile group of wetland associated species. Large numbers of...
The Mariana Swiftlet (Aerodramus bartschi) (Aves: Apodidae) is endemic to the Mariana Islands, where it currently occurs on Saipan, Aguiguan, and Guam. An introduced population of Mariana Swiftlets is also present on O'ahu in the Hawaiian Islands. Sparing interference with the endangered population in the Marianas, the introduced, surrogate population...
Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
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Dana M. Sanchez
Identifying habitat and spatial requirements of wildlife species across
The endemic avifauna of Guam and the Mariana Islands represent a unique assemblage of bird species found nowhere else in the world and thus, are of considerable biological and conservation importance. Unfortunately, most of these species are understudied and exist in precariously low populations. The endangered Mariana Common Moorhen (Gallinula...
Forest harvest persists as one of the most globally important industries, and crucially provides raw wood products for both building and fuel materials. Mechanistically complex abiotic and biotic processes curb ecosystem recovery following timber harvest and it is of great importance to understand the effects of this practice on biogeochemical...
The number of endangered species is rapidly increasing while paucity of adequate information and resources delays establishment of conservation actions. The IUCN’s listing system is insufficient to determine conservation priorities and many species lack information even to be evaluated (i.e., “data deficient”). Here I proposed and tested the Rapid Endangered...
Island systems and species are susceptible to extinction because of their small population size and an ecological naiveté from an evolutionary past lacking strong competition and predation. For example, only one-fifth of the world’s bird species occur on islands, yet more than 90% of the avian extinctions witnessed during historic...
This collection of three manuscripts serves to improve methods for collecting, interpreting, and utilizing autocorrelated data from headwater stream networks. Each stream network is comprised of linear segments. These segments lie within a unique branching structure that connects the segments via flowing water, and the connectivity provided by water varies...
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...
This study investigated variation in xylem anatomy, hydraulic properties, and the relationship between anatomy and properties within Douglas-fir trees at multiple scales. The hierarchical scales in the study included fertilization treatments (fertilized and unfertilized), trees within the treatments, and positions within the trees. Tracheid diameter, tracheid length, percent latewood, number...
This study investigated variation in xylem anatomy, hydraulic properties, and the relationship between anatomy and properties within Douglas-fir trees at multiple scales. The hierarchical scales in the study included fertilization treatments (fertilized and unfertilized), trees within the treatments, and positions within the trees. Tracheid diameter, tracheid length, percent latewood, number...
A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on...
The Demonstration of Ecosystem Management Options (DEMO) study is a large-scale, multi-year, interdisciplinary project examining the effects of various levels and patterns of green-tree retention on multiple forest features. Six retention levels and patterns were examined and replicated across six blocks of predominately Douglas-fir forested land in western Oregon and...
We isolated and characterized the expression of two genes from Populus
trichocarpa that are homologous to the TERMINAL FLOWER 1 (TFL1) gene from
the model annual plant Arabidopsis. In Arabidopsis, overexpression of the TFL1
gene extends the vegetative growth phase, and the homozygous mutant tfl1 allele
causes early flowering and...
Severe scouring from splash damming was one of the earliest reported forms of widespread anthropogenic disturbance in streams of the Pacific Northwest, USA. Splash damming was a common method of log transport in western Oregon from the 1880s through the 1950s. Before being released in large freshets to downstream lumber...
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Kelly M. Burnett Joseph L. Ebersole
Severe scouring from splash damming was one
I conducted acoustic lure surveys of northern pygmy-owls (Glaucidium gnoma) on transects that were systematically placed in forested areas throughout the state of Oregon. My objectives were to determine if pygmy-owls were associated with particular forest types, ecoregions, or with large-diameter dominant overstory trees. I also examined temporal variation in...
Hemlock woolly adelgid, Adelges tsugae Annand, is a destructive introduced pest of hemlock trees in eastern North America, and management has focused on the use of natural enemies through classical biological control. Two species of chamaemyiid flies, Leucopis argenticollis Zetterstedt and Leucopis atrifacies (Aldrich) have been collected previously from western...
Northern Spotted Owls (Strix occidentalis caurina) inhabit productive forests that historically supported frequent, large, variable-severity fires in the Klamath province of southwestern Oregon occur in complex. The potential for high-severity wildfire remains high throughout this region, so remaining spotted owl habitat is at risk. An adaptive management approach to fire...
Within the sagebrush steppe ecosystem, invasive annual grasses are of growing management concern as they outcompete native vegetation, change the fundamental nutrient cycling processes, decrease biodiversity, and increase frequency of wildfires. The most widely used and effective management tool to decrease invasive annual grass abundance, is the use of pre-emergent...
Net uptake of carbon from the atmosphere (net ecosystem production, NEP) is dependent on climate, disturbance history, management practices, forest age, and forest type. To improve understanding of the influence of these factors on forest carbon flux in the western U.S., a combination of federal inventory data and supplemental ground...
I measured responses of free-ranging Rocky Mountain elk (Cervus elaphus) to recreational disturbance at Starkey Experimental Forest and Range, Oregon from April to October, 2003 and 2004. Resting, feeding, and travel activities of 13 cow elk were recorded at 5-minute intervals using Actiwatch™ motion sensors. Elk were subjected to four...
The purpose of this study was to understand the influence of organic material and nutrients from spawning salmon and supplemented salmon carcasses on stream food webs. My study objectives were to examine 1) assimilation of salmon-derived nutrients (SDN) by producers and consumers in the food web, 2) epilithic biofilm productivity,...
The Humboldt marten, Martes americana humboldtensis, has undergone a dramatic decline throughout its historical distribution in coastal Northwestern California. There is currently only one known population occupying an area occurring in <5% of the historical distribution of the subspecies. Conservation and management efforts to benefit this population are hampered by...
Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and...
Sagebrush steppe ecosystems in the Great Basin have become increasingly threatened by the proliferation of cheatgrass (Bromus tectorum L.), an invasive annual grass. Diverse sagebrush and perennial bunchgrass landscapes can be converted to homogenous cheatgrass grasslands mainly through the effects of fire. Although the consequences of this conversion are well...
This dissertation focuses on science relevant to the design and implementation of marine reserves. The chapters explore a range of topics related to among-site variation in population, community, and ecosystem dynamics. My results demonstrate the value and feasibility of integrating this knowledge into more comprehensive conservation and management approaches. While...
The Pigeon Guillemot (Cepphus columba) is now the only species of marine bird in Prince William Sound (PWS), Alaska that is listed as "not recovering" on the Exxon Valdez Oil Spill (EVOS) Trustee Council's Injured Resources List and has shown no sign of population recovery. During the 20 years since...
Forest managers are challenged to provide timber revenues and other resources for society while protecting and enhancing components of biodiversity that are often associated with older forests or older forest structure, such as dead wood. We examined small mammal response to timber harvest in stands 8-10 years following group-selection, two-story,...
Incidental bycatch in commercial fisheries has been identified as a threat to black-footed albatrosses (Phoebastria nigripes) and Laysan albatrosses (P. immutabilis). Effective long-term conservation of these albatrosses necessitates a thorough understanding of their marine distribution, which marine habitats are selected during foraging, and where they are most likely to interact...
The semi-arid sagebrush steppe ecosystem is one of the largest biomes in
North America. The steppe provides critical habitat and forage for wildlife and is
economically important to recreation and livestock industries. However, the ecosystem
is threatened primarily due to several negative effects associated with expansion of the
exotic annual...
Changes in climate caused by increased concentrations of carbon dioxide (CO₂) in the Earth’s atmosphere have led land and ocean surface temperatures to increase by 0.85°C and sea level to increase by 19 cm relative to preindustrial times. Global climate change will lead to further alterations in mean temperature and...
Hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) is an arboreal, hemiparasitic plant that principally parasitizes western hemlock (Tsuga heterophylla). Hemlock dwarf mistletoe exerts a profound influence on infected trees that can drastically change the structure of the tree crown due to reduced growth, top dieback, branch deformation and death, resulting...
The objective of this dissertation was to examine trade-offs and synergies between multiple ecosystem services derived from plantation forests in the coastal Pacific Northwest. I accomplished this in five chapters. In the first chapter I provided background information for the study. In the next chapter I set the context for...
Western juniper has increased in density and distribution in the interior Pacific Northwest since the late 1800s. Management
goals for many juniper woodlands are now focused on reducing tree densities and promoting biodiversity, prompting the use of
fuel reduction treatments. Fuel reduction often involves mechanical cutting and disturbances such as...
Early establishment of competing vegetation often presents an obstacle to the success of planted white spruce (Picea glauca (Moench) Voss) seedlings. We followed growth and development of white spruce and associated vegetation for up to 17 years in Alaska's boreal forests to quantify roles of overtopping plant cover in suppressing...
Following high-severity fire, forest succession may take alternate pathways depending on the pattern of the fire and any secondary disturbances during early stand development, with lasting consequences for ecosystem function. The objectives of this research were to quantify: (1) early postfire regeneration as influenced by the spatial pattern of a...
Hummingbirds are among the smallest birds in the world, only 3 to
4 inches long and about 1⁄10 ounce. They may be small, but these beautiful birds are easy to see and fun to watch.
Hummingbirds feed on nectar and small insects. They get most of their water from nectar.
Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae infested western hemlocks in Oregon and Washington and reared them on...
Key message Leyland cypress, an intergeneric hybrid, produces the same volatile heartwood compounds as its parental taxa, yellow-cedar and Monterrey cypress. However, the proportion of total sesquiterpenes and some of the individual components appear unique to their respective heartwoods.
Context Leyland cypress, xHesperotropsis leylandii is an intergeneric hybrid between yellow-cedar,...
• Hydraulic vulnerability of Douglas-fir (Pseudotsuga menziesii) branchlets
decreases with height, allowing shoots at greater height to maintain hydraulic
conductance (Kshoot) at more negative leaf water potentials (Ψl).
• To determine the basis for this trend shoot hydraulic and tracheid anatomical
properties of foliage from the tops of Douglas-fir trees...
Premise of the study: The Pacific Northwest of North America experiences relatively mild winters and dry summers. For the
tall coniferous trees that grow in this region, we predicted that loss in the hydraulic conductivity of uppermost branches would
be avoided because of difficulty reversing accumulated emboli in xylem that...
We studied habitat selection by northern spotted owls (Strix occidentalis caurina) during natal dispersal in Washington State, USA, at both the roost site and landscape scales. We used logistic regression to obtain parameters for an exponential resource selection function based on vegetation attributes in roost and random plots in 76...
Six species of Cystangium, a genus of
sequestrate taxa related to Russula, were collected
in Patagonia (Argentina and Chile) during autumn
2001. Two species, C. depauperatum Singer & A.H.
Sm. and C. nothofagi (E. Horak) Trappe, Castellano &
T. Lebel, were already known from this region, while
four new species,...
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...
We present an atmospheric inverse modeling framework to constrain terrestrial biosphere CO₂ exchange processes at subregional scales. The model is operated at very high spatial and temporal resolution, using the state of Oregon in the northwestern United States as the model domain. The modeling framework includes mesoscale atmospheric simulations coupled...
This study investigated how lidar-derived vegetation indices, disturbance history from Landsat time series (LTS)
imagery, plot location accuracy, and plot size influenced accuracy of statistical spatial models (nearest-neighbor
imputation maps) of forest vegetation composition and structure. Nearest-neighbor (NN) imputation maps were
developed for 539,000 ha in the central Oregon Cascades,...
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, H. S. J., Ohmann, J. L., Roberts, H. M., Gregory, M. J., Henderson, E. B.,
McGaughey, R. J
We evaluated effects of chemical fertilizer, spacing, and interplanted nitrogen-fixing trees on wood density and diameter growth of 15-year-old Eucalyptus saligna trees. The trees were grown in silvicultural trials established on former sugarcane land on the island of Hawaii. Elevation was 480 m, slopes were gentle, and annual rainfall averaged...
Current paradigm suggests that spatial and temporal competition for resources limit an exotic invader, cheatgrass (Bromus
tectorum L.), which once established, alters fire regimes and can result in annual grass dominance in sagebrush steppe.
Prescribed fire and fire surrogate treatments (mowing, tebuthiuron, and imazapic) are used to reduce woody fuels...
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...
Riparian-zone vegetation can influence terrestrial and aquatic food webs through variation in the amount, timing, and nutritional content of leaf and other litter inputs. We investigated how riparianforest community composition, understory density, and lateral slope shaped vertical and lateral litter inputs to 16 streams in the Oregon Coast Range. Riparian...
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...
Montane meadows in the Cascade Range of Oregon have been declining due to tree establishment since records began. Montane meadow complexes in the H.J. Andrews Experimental Forest shrank by 60 to 75% from 1949 to 2005, but fine scale temporal and spatial processes of tree establishment in these meadows are...
Field trials were conducted during 2001 to 2003 to investigate soil population dynamics of Meloidogyne chitwoodi, tuber symptom suppression using oxamyl, and post-harvest tuber symptom development on short-season potato varieties Russet Norkotah and Russet Nugget (San Luis Valley only). The experiments were located in the San Luis Valley in Colorado,...
We examined terrestrial amphibians in managed headwater forest stands in western Oregon from 1998 to 2009. We assessed: (1) temporal and spatial patterns of species capture rates, and movement patterns with distance from streams and forest management treatments of alternative riparian buffer widths and upland thinning; (2) species survival and...
Cheatgrass (Bromus tectorum L.) is a widespread exotic weed in the Intermountain sagebrush steppe. An annual grass, it is highly prolific and very competitive with native perennial grass seedlings. A clipping experiment carried out at two cheatgrass-dominated sites (Lincoln Bench and Succor Creek) in eastern Oregon analyzed effects of defoliation...
Recently the National Park Service has proposed raising fence heights to exclude mouflon sheep (Ovis musimon) from conservation areas at Hawai'i Volcanoes National Park. Concern over previous mortality of Hawaiian Petrels (Pterodronia sandwichensis) due to collision with fences prompted this study to quantify the potential effects of raising fence heights...
Forested riparian buffers isolate streams from the influence of harvesting operations that can lead to water temperature increases. Only forest cover between the sun and stream limits stream warming, but that cover also reduces instream photosynthesis, aquatic insect production, and fish productivity. Water temperature increases that occur as streams flow...
Mountain Quail (Oreortyx pictus) populations have declined in the eastern portion of their range during the last century. However, few studies have investigated the nesting habitat and survival of Mountain Quail translocated into an area from which they have been extirpated. We translocated 217 wild Mountain Quail (Oreortyx pictus) from...
Little is known on the importance of riparian areas to birds near small headwater streams in mesic forests. Progress towards understanding limiting factors that affect bird populations has been difficult because of lack of information beyond the breeding period. I compared bird assemblages between headwater riparian and upland areas throughout...
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...
Accurate estimates of forest aboveground biomass are needed to reduce uncertainties in the terrestrial carbon flux. The Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land Elevation Satellite is now the first spaceborne lidar sensor that will provide global estimates of vegetation height. This study investigated the utility...
Coarse woody debris (CWD), represented by logs and snags >10 cm in diameter and >1 m in length, was sampled at eight sites in Russian boreal forests to determine the specific density of decay classes and decomposition rates. Tree species sampled included Abies siberica Ledeb., Betula pendula Roth., Betula costata...
Despite the importance of tropical forest ecosystems in the global carbon cycle, there have been few studies of carbon dynamics in this biome. The magnitude of carbon stocks in the tropics and their changes over time are poorly known since ground-based observations are lacking. In this study, total carbon stocks...
The sagebrush steppe ecosystem of the northern Great Basin is severely degraded and continues to decline due in large part to the invasive, non-native annual grasses Bromus tectorum L. (cheatgrass) and Taeniatherum caput-medusae (L.) Nevski (medusahead). Restoration of invasive-dominated areas is difficult, but can be enhanced by adding a carbon...
Fire exclusion has been associated with structural and compositional changes
in many upland forests of the western United States, but little is known about the
impacts on riparian forests, portions of the landscape protected for habitat and water
quality. For this study, I characterized the historic disturbance and tree recruitment...
This study examines the long-term role of interference on stand development of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and red alder (Alnus rubra Bong.) planted mixtures in the Central Cascades of Oregon, USA. The two species are common associates in naturally regenerated and planted conifer stands in the Pacific Northwest. Due...
Cell lines were established from spleen and heart tissues of a juvenile white sturgeon Acipenser transmontanus and designated WSS-2 and WSH-1, respectively. Isoenzyme analyses of both lines confirmed their host of origin. Both lines were hypotetraploid and possessed micro- and macrochromosomes. The modal chromosome number for the WSS-2 line was...
We have a poor understanding of the biotic communities in zero-order basins, drainages extending from ridgelines to the initiation of first-order streams. This study describes baseline plant and amphibian composition in unmanaged zero-order basins in the Oregon Coast Range. Specifically, I studied: i) the spatial distribution and diversity of species,...
Though the mixed-evergreen forests of the Klamath Siskiyous have a long history of large, mixed-severity fires, most research in this region has concentrated on the impacts of high-severity fire. Knowledge of the ecological effects of low- and moderate-severity areas within mixed-severity fires is important because such areas may account for...
I conducted field studies to determine the effect of insect herbivory and
intraspecific plant competition on ragwort Senecio jacobaea. The objectives were to
determine the patterns and causes in the distribution of the ragwort flea beetle
Longitarsus jacobaeae foraging among varying densities of ragwort, to measure the
behavioral and numerical...
Scientists and land managers realize that integrated weed management (IWM) strategies are needed to attain successful and lasting improvements of weed infested landscapes. At this time no broadly reliable and environmentally safe IWM strategy has been developed to control exotic annual grasses that dominate many ecosystems of the northern Great...
The forest alpine tundra ecotone (FTE, also known as alpine treeline or subalpine parkland), is a conspicuous feature of mountain landscapes throughout the world. Climate change-driven increases in temperature are believed to result in FTE movement and tree invasion of subalpine meadows, which have been documented throughout the Northern Hemisphere...
Without the natural occurrence of fire in ponderosa pine forests of the western US, lodgepole pine has started to dominate regeneration in many forest stands and may be gradually replacing ponderosa pine over time. This development, however, conflicts with recent efforts in this region to restore old-aged, open ponderosa pine...
Fire is a fundamental disturbance that drives terrestrial and atmospheric carbon dynamics. Previous studies have quantified fire effects on carbon cycling from local to global scales but have focused nearly exclusively on high-severity, stand-replacement fire. Since 2002, variable-severity wildfires have burned more than 65 000 ha across the east slope...
Carbon sequestration in tropical secondary forests growing in all climates must be quantified to understand their potential role in adaptation and mitigation strategies of global climate change. Total aboveground biomass (TAGB), soil carbon, and total ecosystem carbon (TEC) were measured in 54 secondary forests growing along a broad bioclimatic gradient...
Western forests have become increasingly fragmented landscapes dominated by young stands. Given that western Oregon forests largely consist of headwater systems, there is a need to better understand how headwater forest taxa and their habitats are impacted by forest management practices. Several amphibian species associated with forested headwater systems have...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...
Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir (Pseudotsuga menziesii) forest soils and have been estimated to cover up to 40% of the forest floor in some stands. Although previous studies have examined various aspects of EcM fungi, little is known about their associated microbial...
This special issue presents short-term ecological effects of restoration treatments imposed as part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP), and summarizes
public attitude survey results related to restoration efforts.
Funded by the US Joint Fire Science Program (JFSP; 2005-2011), the Bureau of Land Management (BLM; 2011 to present),...
Among the many birds attracted to gardens, hummingbirds can be the most appealing. Not only are these “garden jewels” fun to watch, hummingbirds play an important role in our environment by pollinating flowers and feeding on insects. Attracting hummingbirds to your garden is easy. You have a good chance of...
1. Ecosystem invasibility is determined by combinations of environmental variables, invader attributes, disturbance regimes, competitive abilities of resident species and evolutionary history between residents and disturbance regimes. Understanding the relative importance of each factor is critical to limiting future invasions and restoring ecosystems.
2. We investigated factors potentially controlling Bromus...
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...
The study of reptiles and amphibians is called herpetology. The word “herps” comes from the same root word. Herps in your landscape are fun to watch, interesting to learn about, and a benefit to your local ecology. You can attract them by adapting your yard to their habitat needs.