AmeriFlux US-Vcm Valles Caldera Mixed Conifer

DOE Data Explorer

Litvak, Marcy [University of New Mexico

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Vcm Valles Caldera Mixed Conifer. Site Description - The Valles Caldera Mixed Conifer site is located in the 1200 km2 Jemez River basin in north-central New Mexico. Common to elevations ranging from 3040 to 2740 m in the region, the mixed conifer stand, within the entirety of the tower footprint in all directions, provides an excellent setting for studying the seasonal interaction between snow and vegetation.

Detection of aspen/conifer forest mixes from multitemporal LANDSAT digital data. [Bear River Range, Rocky Mountains

NASA Technical Reports Server (NTRS)

Merola, J. A.; Jaynes, R. A.; Harniss, R. O.

1983-01-01

Aspen, conifer and mixed aspen/conifer forests were mapped for a 15-quadrangle study area in the Utah-Idaho Bear River Range using LANDSAT multispectral scanner (MSS) data. The digital MSS data were utilized to devise quantitative indices which correlate with apparently stable and seral aspen forests. The extent to which a two-date LANDSAT MSS analysis may permit the delineation of different categories of aspen/conifer forest mix was explored. Multitemporal analyses of MSS data led to the identification of early, early to mid, mid to late, and late seral stages of aspen/conifer forest mixing.

Distribution and diversity of fungal species in and adjacent to the Los Alamos National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balice, R.G.; Jarmie, N.; Rogers, F.J.

1997-12-01

Fungi have demonstrated their ability to diversify and specialize to take advantage of new environments (Murphy 1996). These species are essential to the normal functioning of ecosystems and the impacts of human activities may be harmful to fungi. There is a need to inventory fungi throughout the range of their environments. Previously archived information representing 43 sample locations was used to perform a preliminary evaluation of the distributions and diversity of fungal species at the Los Alamos National Laboratory and in adjacent environments. Presence-absence data for 71 species of fungi in five habitats, pinon-juniper, canyon-bottom ponderosa pine, ponderosa pine, canyon-bottommore » mixed conifer, and mixed conifer were analyzed. The results indicate that even though fungi occur in each of the habitats, fungal species are not distributed evenly among these habitats. The richness of fungal species is greater in the canyon-bottom mixed conifer and mixed conifer habitats than in the pinon-juniper, canyon-bottom ponderosa pine or ponderosa pine habitats. All but three of the fungal species were recorded in either the canyon-bottom mixed conifer or the mixed conifer habitats, and all but seven of the fungal species were found in the mixed conifer habitat.« less

Mixed-severity fire fosters heterogeneous spatial patterns of conifer regeneration in a dry conifer forest

Treesearch

Sparkle L. Malone; Paula J. Fornwalt; Mike A. Battaglia; Marin E. Chambers; Jose M. Iniguez; Carolyn H. Sieg

2018-01-01

We examined spatial patterns of post-fire regenerating conifers in a Colorado, USA, dry conifer forest 11-12 years following the reintroduction of mixed-severity fire. We mapped and measured all post-fire regenerating conifers, as well as all other post-fire regenerating trees and all residual (i.e., surviving) trees, in three 4-ha plots following the 2002 Hayman Fire...

Vegetation and Ecological Characteristics of Mixed-Conifer and Red Fir Forests at the Teakettle Experimental Forest

Treesearch

Malcolm North; Brian Oakley; Jiquan Chen; Heather Erickson; Andrew Gray; Antonio Izzo; Dale Johnson; Siyan Ma; Jim Marra; Marc Meyer; Kathryn Purcell; Tom Rambo; Dave Rizzo; Brent Roath; Tim Schowalter

2002-01-01

Detailed analysis of mixed-conifer and red fir forests were made from extensive, large vegetation sampling, systematically conducted throughout the Teakettle Experimental Forest. Mixed conifer is characterized by distinct patch conditions of closed-canopy tree clusters, persistent gaps and shrub thickets. This heterogeneous spatial structure provides contrasting...

Stand dynamics of mixed red alder-conifer forests of southeast Alaska.

Treesearch

Robert L. Deal; Paul E. Hennon; Ewa H. Orlikowska; David V. D' Amore

2004-01-01

Stand structure and dynamics were evaluated in mixed red alder (Alnus rubra Bong.) - conifer forests of southeast Alaska. We assessed stand development, tree density, total basal area, diameter distribution of live and dead trees, height distribution of live trees, and mean diameter of all and largest conifers in 40-year-old red alder - conifer...

Tree mortality in drought-stressed mixed-conifer and ponderosa pine forests, Arizona, USA

Treesearch

Joseph L. Ganey; Scott C. Vojta

2011-01-01

We monitored tree mortality in northern Arizona (USA) mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forests from 1997 to 2007, a period of severe drought in this area. Mortality was pervasive, occurring on 100 and 98% of 53 mixed-conifer and 60 ponderosa pine plots (1-ha each), respectively. Most mortality was attributable to a suite of forest...

Post-fire epicormic branching in Sierra Nevada Abies concolor (white fir)

Treesearch

Chad T. Hanson; Malcolm P. North

2006-01-01

In California's mixed-conifer forest, which historically had a regime of frequent fires, two conifers, Sequoiadendron giganteum and Pseudotsuga menziesii, were previously known to produce epicormic sprouts from branches. We found epicormic branching in a third mixed-conifer species, Abies concolor, 3 and 4...

Resource-dependent growth models for Sierran mixed-conifer saplings

Treesearch

S.W. Bigelow; M.P. North; W.R. Horwath

2009-01-01

Thinning to reduce wildfire hazard is a common management practice in frequent-fire forests of the American west, but it is uncertain whether projects will help regenerate fire-resistant, shade-intolerant pines. We studied naturally established saplings of six conifer species in mixed-conifer forest in northern California, USA to...

First-year postfire and postharvest soil temperatures in aspen and conifer stands

Treesearch

Michael C. Amacher; Amber D. Johnson; Debra E. Kutterer; Dale L. Bartos

2001-01-01

Aspen (Populus tremuloides Michx.) stands are in decline throughout the Interior Western United States because of fire suppression, overbrowsing by domestic livestock and native ungulates, and forest succession. We measured summertime soil temperatures in stable aspen, decadent aspen, and mixed aspen/conifer stands; a mixed aspen/conifer clearcut;...

Stand structure and stocking control in Appalachian mixed hardwoods

Treesearch

George R., Jr. Trimble; H. Clay Smith

1976-01-01

Uneven-aged management using a "q" technique for structure control is discussed for Appalachian mixed hardwoods. The success in attaining stand structure goals with periodic selection cuts was evaluated. Where these goals had not been reached, the authors speculated, on the basis of current stand conditions, whether they would be reached, and if so, when. For...

The ecology and management of moist mixed-conifer forests in eastern Oregon and Washington: a synthesis of the relevant biophysical science and implications for future land management

Treesearch

Peter Stine; Paul Hessburg; Thomas Spies; Marc Kramer; Christopher J. Fettig; Andrew Hansen; John Lehmkuhl; Kevin O' Hara; Karl Polivka; Peter Singleton; Susan Charnley; Andrew Merschel; Rachel White

2014-01-01

Land managers in the Pacific Northwest have reported a need for updated scientific information on the ecology and management of mixed-conifer forests east of the Cascade Range in Oregon and Washington. Of particular concern are the moist mixed-conifer forests, which have become drought-stressed and vulnerable to high-severity fire after decades of human disturbances...

Detection of aspen-conifer forest mixes from LANDSAT digital data. [Utah-Idaho Bear River Range

NASA Technical Reports Server (NTRS)

Jaynes, R. A.; Merola, J. A.

1982-01-01

Aspen, conifer and mixed aspen/conifer forests were mapped for a 15-quadrangle study area in the Utah-Idaho Bear River Range using LANDSAT multispectral scanner data. Digital classification and statistical analysis of LANDSAT data allowed the identification of six groups of signatures which reflect different types of aspen/conifer forest mixing. Photo interpretations of the print symbols suggest that such classes are indicative of mid to late seral aspen forests. Digital print map overlays and acreage calculations were prepared for the study area quadrangles. Further field verification is needed to acquire additional information about the nature of the forests. Single date LANDSAT analysis should be a cost effective means to index aspen forests which are at least in the mid seral phase of conifer invasion. Since aspen canopies tend to obscure understory conifers for early seral forests, a second date analysis, using data taken when aspens are leafless, could provide information about early seral aspen forests.

Canopy openings and white-tailed deer influence the understory vegetation in mixed oak woodlots

Treesearch

Todd W. Bowersox; Gerald L. Storm; Walter M. Tzilkowski

1995-01-01

Effects of canopy opening and white-tailed deer on ground level vegetation are being assessed in south-central Pennsylvania. Herbaceous plants and woody seedlings are being monitored in three unevenaged, mixed oak woodlots at Gettysburg National Military Park. Canopy opening levels on 0.20 ha treatment units were closed (~100% canopy), small (50-60% canopy) and large (...

Determining maximum stand density index in mixed species stands for strategic-scale stocking assessments

Treesearch

Chris W. Woodall; Patrick D. Miles; John S. Vissage

2005-01-01

Stand density index (SDI), although developed for use in even-aged monocultures, has been used for assessing stand density in large-scale forest inventories containing diverse tree species and size distributions. To improve application of SDI in unevenaged, mixed species stands present in large-scale forest inventories, trends in maximum SDI across diameter classes...

Coarse-scale population structure of pathogenic Armillaria species in a mixed-conifer forest in the Blue Mountains of northeast Oregon.

Treesearch

B.A. Ferguson; T.A. Dreisbach; C.G. Parks; G.M. Filip; C.L. Schmitt

2003-01-01

The coarse-scale population structure of pathogenic Armillaria (Fr.) Staude species was determined on approximately 16 100 ha Of relatively dry, mixed-conifer forest in the Blue Mountains of northeast Oregon. Sampling of recently dead or live, symptomatic conifers produced 112 isolates of Armillaria from six tree species.

A dendrochronology based fire history of Jeffry pine-mixed conifer forests in the Sierra San Pedro Martir, Mexico

Treesearch

Scott L. Stephens; Carl N. Skinner; Samantha J. Gill

2003-01-01

Conifer forests in northwestern Mexico have not experienced systematic fire suppression or logging, making them unique in western North America. Fire regimes of Pinus jeffreyi Grev. & Balf. mixed conifer forests in the Sierra San Pedro Martir, Baja California, Mexico, were determined by identifying 105 fire dates from 1034 fire scars in 105 specimens. Fires were...

Silviculture of mixed conifer forests in eastern Oregon and Washington.

Treesearch

K.W. Seidel; P.H. Cochran

1981-01-01

The silviculture of mixed conifer forests in eastern Oregon and Washington is described. Topics discussed include ecological setting, damaging agents, silviculture, and management. The relevant literature is presented, along with unpublished research, experience, and observations. Research needs are also proposed.

PHOTOCHEMICAL AIR POLLUTANT EFFECTS ON MIXED CONIFER ECOSYSTEMS

EPA Science Inventory

In 1972, a multi-disciplinary team of ecologists assembled to monitor and analyze some of the ecological consequences of photochemical oxidant air pollutants in California Mixed Conifer Forest ecosystems of the San Bernardino Mountains east of Los Angeles. The purposes included g...

The role of low impact herbicide treatments in ecosystem management

Treesearch

Charles K. McMahon; James H. Miller; David F. Thomas

1994-01-01

Abstract. Environmentally safe, selective herbicide treatments can be adapted to manage habitats and direct succession toward desired future conditions within the principles of ecosystem 0. Six roles for herbicide treatments in ecosystem management are suggested: create and maintain desired habitats; create mixed and uneven-aged stands; restore...

Management options for mitigating Nitrogen (N) losses from N-saturated mixed-conifer forests in California

Treesearch

Benjamin S. Gimeno; Fengming Yuan; Mark E. Fenn; Thomas Meixner

2009-01-01

Mixed-conifer forests of southern California are exposed to nitrogen (N) deposition levels that impair carbon (C) and N cycling, enhance forest flammability, increase the risk of fire occurrence and air pollution emissions in fire, and increase nitrate...

Historical dominance of low-severity fire in dry and wet mixed-conifer forest habitats of the endangered terrestrial Jemez Mountains salamander (Plethodon neomexicanus)

USGS Publications Warehouse

Margolis, Ellis; Malevich, Steven B.

2016-01-01

Anthropogenic alteration of ecosystem processes confounds forest management and conservation of rare, declining species. Restoration of forest structure and fire hazard reduction are central goals of forest management policy in the western United States, but restoration priorities and treatments have become increasingly contentious. Numerous studies have documented changes in fire regimes, forest stand structure and species composition following a century of fire exclusion in dry, frequent-fire forests of the western U.S. (e.g., ponderosa pine and dry mixed-conifer). In contrast, wet mixed-conifer forests are thought to have historically burned infrequently with mixed- or high-severity fire—resulting in reduced impacts from fire exclusion and low restoration need—but data are limited. In this study we quantified the current forest habitat of the federally endangered, terrestrial Jemez Mountains salamander (Plethodon neomexicanus) and compared it to dendroecological reconstructions of historical habitat (e.g., stand structure and composition), and fire regime parameters along a gradient from upper ponderosa pine to wet mixed-conifer forests. We found that current fire-free intervals in Jemez Mountains salamander habitat (116–165 years) are significantly longer than historical intervals, even in wet mixed-conifer forests. Historical mean fire intervals ranged from 10 to 42 years along the forest gradient. Low-severity fires were historically dominant across all forest types (92 of 102 fires). Although some mixed- or highseverity fire historically occurred at 67% of the plots over the last four centuries, complete mortality within 1.0 ha plots was rare, and asynchronous within and among sites. Climate was an important driver of temporal variability in fire severity, such that mixed- and high-severity fires were associated with more extreme drought than low-severity fires. Tree density in dry conifer forests historically ranged from open (90 trees/ha) to moderately dense (400 trees/ha), but has doubled on average since fire exclusion. Infill of fire-sensitive tree species has contributed to the conversion of historically dry mixedconifer to wet mixed-conifer forest. We conclude that low-severity fire, which has been absent for over a century, was a critical ecosystem process across the forest gradient in Jemez Mountains salamander habitat, and thus is an important element of ecosystem restoration, resilience, and rare species recovery.

Opportunities abound for affordable mechanical fuels treatment in dry mixed-conifer forests

Treesearch

Jeremy S. Fried; Theresa B. Jain

2013-01-01

The dry mixed-conifer forests that cover millions of acres in 12 western states experience low- to mixed-severity fire regimes; are typically heterogeneous in species composition, forest structure, and fuel dynamics; and grow quickly enough to generate concern about fuel treatment longevity. Yet compared to stands of pure ponderosa pine, there has been little research...

Geographic variation in mixed-conifer forest fire regimes in California

Treesearch

Beaty R. Matthew; Taylor Alan H.

2008-01-01

This paper reviews recent research from California on geographic variability in mixed conifer(MC) forest fire regimes. MC forests are typically described as having experienced primarilyfrequent, low to moderate severity burns prior to fire suppression that created a mosaic ofvegetation patches with variable structure. Research...

Silviculture of southwestern mixed conifers and aspen: the status of our knowledge

Treesearch

John R. Jones

1974-01-01

Describes the status of our knowledge about mixed conifer silviculture in the interior Southwest. Ecological background is reviewed first, followed by description of silvicultural methods. Relevant literature is discussed, along with observations, experience, and results of unpublished research. Contains unpublished input by subject-matter specialists and southwestern...

Air pollution impacts in the mixed conifer forests of southern California

Treesearch

Patrick J. Temple; Andrzej Bytnerowicz; Mark E. Fenn; Mark A. Poth

2005-01-01

Air pollution, principally in the form of photochemical ozone and deposition of nitrogen compounds, has significantly affected mixed conifer forests in the mountains of southern California. Foliar injury, premature needle abscission, crown thinning, and reduced growth and vigor have been well documented, particularly for ponderosa (Pinus ponderosa...

Truffle abundance in riparian and upland mixed-conifer forest of California's southern Sierra Nevada

Treesearch

Marc D. Meyer; Malcolm P. North

2005-01-01

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 in riparian than upland sites in old-growth, mixed-...

Ecosystem management and our national forests -- is there a role for forest herbicides?

Treesearch

Charles K. McMahon; J.H. Miller; D.F. Thomas

1994-01-01

Abstract.Environmentally safe, selective herbicide treatments can be adapted to manage habitats and direct succession toward desired future conditions within the principles of Ecosystem Management (EM). Six roles for herbicide treatments in EM are suggested: create and maintain desired habitats; create mixed and unevenaged stands; restore damaged...

Prescribing Control in Mixed Conifer Stands Affected by Annosus Root Disease

Treesearch

Gary Petersen

1989-01-01

Tree mortality caused by root diseases constitutes a major drain on Forest productivity of mixed-conifer stands. Factors such as changes in species composition, selective harvesting, unfavorable economic climate, and optimizing of short-term benefits have contributed to current stand conditions. Computer simulation models, such as the "RRMOD Computerized Root...

Stand conditions associated with tree regeneration in sierran mixed-conifer forests.

Treesearch

Andrew N. Gray; Harold S.J. Zald; Ruth A. Kern; Malcolm North

2005-01-01

Fire suppression has significantly increased canopy cover, litter depth, and stem density in many western forests, altering microsite conditions that affect tree seedling establishment. We conducted studies in a mixed-conifer forest in the Sierra Nevada, California, to determine relationships between established understory trees and microsite quality, and to examine...

Restoring fire to mixed conifer forests in the Northern Cascades

Treesearch

T. J. Leuschen

1996-01-01

Many of the ponderosa pine (Pinus ponderosa) mixed conifer stands in the Methow Valley of north-central Washington have developed understories of Douglas-fir (Pseudotsuga rnenziesii) as a result of fire exclusion. Most of the forest floor has not yet become cluttered with dead woody fuel. Instead, the live biomass has increased and...

Bushy-tailed woodrat abundance in dry forests of eastern Washington.

Treesearch

John F. Lehmkuhl; Keith D. Kistler; James S. Begley

2006-01-01

We studied bushy-tailed woodrats (Neotonza cinerea occidentalis) in the eastern Washington Cascade Range to estimate their density and survival in 3 typical dry forest cover types. We predicted woodrat density to be high, moderate, and low in mature mixed-conifer forests, young mixed-conifer forests, and open ponderosa pine forests, respectively....

Uneven-aged management after a half-century of research on the Forest Service Fernow Experimental Forest in West Virgina

Treesearch

Thomas M. Schuler

2014-01-01

Uneven-age management in forestry refers to a system of management that periodically selects individual trees or small groups of trees for harvest. In general, the concept of uneven-age management entails the sustained yield of forest products while maintaining continuous forest cover. In North America, interest in uneven-age management grew in the second half of the...

Do pine trees in aspen stands increase bird diversity?

Treesearch

Mark A. Rumble; Lester D. Flake; Todd R. Mills; Brian L. Dykstra

2001-01-01

In the Black Hills of South Dakota, quaking aspen (Populus tremuloides) is being replaced by conifers through fire suppression and successional processes. Although the Black Hills National forest is removing conifers (primarily ponderosa pine [Pinus ponderosa]) to increase the aspen communities in some mixed stands, Forest Plan guidelines allow four conifers per...

Reducing stand densities in immature and mature stands, Applegate Watershed, Southwest Oregon.

Treesearch

Marty L. Main; Michael P. Amaranthus

1996-01-01

Abstract Throughout the Applegate watershed, dense, overstocked, immature stands of mixed conifers and hardwoods and declining stands of mature conifers present significant and complex silvicultural problems. Stand stagnation is common, as is loss of large-diameter conifers from insects and wildfire. Treatments designed to maintain or encourage development of large-...

Aspen Increase Soil Moisture, Nutrients, Organic Matter and Respiration in Rocky Mountain Forest Communities

PubMed Central

Buck, Joshua R.; St. Clair, Samuel B.

2012-01-01

Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO3 and NH4 were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development. PMID:23285012

Terrain and vegetation structural influences on local avian species richness in two mixed-conifer forests

Treesearch

Jody C. Vogeler; Andrew T. Hudak; Lee A. Vierling; Jeffrey Evans; Patricia Green; Kerri T. Vierling

2014-01-01

Using remotely-sensed metrics to identify regions containing high animal diversity and/or specific animal species or guilds can help prioritize forest management and conservation objectives across actively managed landscapes. We predicted avian species richness in two mixed conifer forests, Moscow Mountain and Slate Creek, containing different management contexts and...

Regeneration in mixed conifer and Douglas-fir shelterwood cuttings in the Cascade Range of Washington.

Treesearch

K.W. Seidel

1983-01-01

A survey of shelterwood cuttings in mixed conifer and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests in the Cascade Range in Washington showed that, on the average, shelterwood units were adequately-stocked with a mixture of advance, natural postharvest, and planted reproduction of a number of species. Shelterwood cuttings in the...

Effects of thinning, residue mastication, and prescribed fire on soil and nutrient budgets in a Sierra Nevada mixed-conifer forest

USDA-ARS?s Scientific Manuscript database

The effects of thinning followed by residue mastication (THIN), prescribed fire (BURN), and thinning plus residue mastication plus burning (T+B) on nutrient budgets and resin-based (plant root simulator [PRS] probe) measurements of soil nutrient availability in a mixed-conifer forest were measured. ...

Effects of thinning, residue mastication, and prescribed fire on soil and nutrient budgets in a Sierra Nevada mixed conifer forest

USDA-ARS?s Scientific Manuscript database

The effects of thinning followed by residue mastication (THIN), prescribed fire (BURN), and thinning plus residue mastication plus burning (T+B) on nutrient budgets and resin-based (plant root simulator [PRS] probe) measurements of soil nutrient availability in a mixed-conifer forest were measured. ...

Trends in snag populations in drought-stressed mixed-conifer and ponderosa pine forests (1997-2007)

Treesearch

Joseph L. Ganey; Scott C. Vojta

2012-01-01

Snags provide important biological legacies, resources for numerous species of native wildlife, and contribute to decay dynamics and ecological processes in forested ecosystems. We monitored trends in snag populations from 1997 to 2007 in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forests, northern Arizona. Median snag density...

Recommendations for snag retention in southwestern mixed-conifer and ponderosa pine forests: History and current status

Treesearch

Joseph L. Ganey

2016-01-01

Snags provide habitat for numerous species of wildlife. Several authors have provided recommendations for snag retention in southwestern mixed-conifer and ponderosa pine (Pinus ponderosa) forests. Most recommendations were presented in terms of minimum snag density and/or size. I summarized the history of recommendations for snag retention in these forest...

Restoring forest health: fire and thinning effects on mixed-conifer forests

Treesearch

Malcolm P. North

2006-01-01

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 to restoring...

Soil moisture and groundwater recharge under a mixed conifer forest

Treesearch

Robert R. Ziemer

1978-01-01

The depletion of soil moisture within the surface 7 m by a mixed conifer forest in the Sierra Nevada was measured by the neutron method every 2 weeks during 5 consecutive summers. Soil moisture recharge was measured periodically during the intervening winters. Groundwater fluctuations within the surface 17 m were continuously recorded during the same period.

Evaluating potential trade-offs among fuel treatment strategies in mixed-conifer forests of the Sierra Nevada

Treesearch

Jens T. Stevens; Brandon M. Collins; Jonathan W. Long; Malcolm P. North; Susan J. Prichard; Leland W. Tarnay; Angela M. White

2016-01-01

Fuel treatments in fire-suppressed mixed-conifer forests are designed to moderate potential wildfire behavior and effects. However, the objectives for modifying potential fire effects can vary widely, from improving fire suppression efforts and protecting infrastructure, to reintroducing low-severity fire, to restoring and maintaining variable forest structure and...

Board foot volumes of young growth mixed conifer timber

Treesearch

W. L. Jackson

1961-01-01

Board foot volumes have been determined for ponderosa pine, sugar pine, white fir, and Douglas-fir in 90-year-old mixed-conifer stands on the Challenge Experimental Forest, near Oroville, California. Productivity is high—site index 140 feet at 100 years. Following the technique described by Boe, the scaled volumes of felled trees were plotted on logarithmic...

Long-term demographic trends in a fire-suppressed mixed-conifer forest

Treesearch

Carrie R. Levine; Flora Krivak-Tetley; Natalie S. van Doorn; Jolie-Anne S. Ansley; John J. Battles

2016-01-01

In the western United States, forests are experiencing novel environmental conditions related to a changing climate and a suppression of the historical fire regime. Mixed-conifer forests, considered resilient to disturbance due to their heterogeneity in structure and composition, appear to be shifting to a more homogeneous state, but the timescale of these shifts is...

Interim definitions for old growth Douglas-fir and mixed-conifer forests in the Pacific Northwest and California.

Treesearch

J.F. Franklin; F. Hall; W. Laudenslayer; C. Maser; J. Nunan; J. Poppino; C.J. Ralph; T. Spies

1986-01-01

Interim definitions of old-growth forests are provided to guide efforts in land-management planning until comprehensive definitions based on research that is currently underway can be formulated. The basic criteria for identifying old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and mixed-conifer forests in western Washington and...

Chapter 6: Creating a basis for watershed management in high elevation forests

Treesearch

Gerald J. Gottfried; Leonard F. DeBano; Peter F. Ffolliott

1999-01-01

Higher mountains and plateaus in the Central Arizona Highlands generally support southwestern mixed conifer forests, associated aspen and spruce-fir forests, and a small acreage of grasslands interspersed among the forested areas. Most of the major rivers in the region originate on headwater watersheds that support mixed conifer forests where annual precipitation,...

Tree crown structure indicators in a natural uneven-aged mixed coniferous forest in northeastern Mexico

Treesearch

Javier Jimenez-Perez; Oscar Aguirre-Calderon; Horst Kramer

2006-01-01

Characterization of tree crown structure provides critical information to assess a variety of ecological conditions for multiple purposes and applications. For biomass growth, for example, tree crowns have basic physiological functions: assimilation, respiration, and transpiration. How tree crowns spatially interact and grow can bring about a seamless landscape of...

Red-cockaded woodpeckers and silvicultural practice: is uneven-aged silviculture preferable to even-aged?

Treesearch

D. Craig Rudolph; Richard N. Conner

1996-01-01

The endangered red-cockaded woodpecker (Picoides borealis) has become a high-profile management issue in the southeastern United States. Suitable habitat consists of mature to old pine, or mixed pine-hardwood forest, with minimal hardwood midstory vegetation. Loss of habitat, detrimental silvicultural practices, and changes in the fire regime have...

Developing regeneration in woodlots at Gettysburg National Military Park

Treesearch

Todd W. Bowersox; Gerald L. Storm; Walter M. Tzilkowski

1993-01-01

Woodlots are significant features of the historic scene at Gettysburg National Military Park, Pennsylvania. Recent inventories of these historic woodlots indicated a general lack of seedling recruitment in the uneven-aged stands with a mature mixed oak overstory and a midstory of ash-cherry-dogwood-hickory. Seedling-sized stems of shrub and tree species were abundant,...

Annosus Root disease of Western Conifers (FIDL)

Treesearch

Craig L. Schmitt; John R. Parmeter; John T. Kliejunas

2000-01-01

Annosus root disease is found on all western conifer species but is of most concern on true firs, hemlocks, and pines. Incense cedar, coast redwood and sequoia are sometimes infected in California. Western juniper is infected throughout its range. Annosus is common and causes extensive decay in old-growth western and mountain hemlock stands. Many mixed conifer stands...

Cacodylic acid for precommercial thinning in mixed-conifer stands shows erratic results.

Treesearch

William W. Oliver

1970-01-01

In a small-scale test, a silvicide consisting of cacodylic acid was injected during the growing season at dosages recommended by the manufacturer. The treatment did not thin adequately two of three mixed-conifer stands. Ponderosa pine and lower crown classes seemed more susceptible to the silvicide than Douglas-fir and upper crown classes. No flashback was recognized....

Biophysical controls on soil respiration in the dominant patch types of an old-growth, mixed-conifer forest

Treesearch

Siyan Ma; Jiquan Chen; John R. Butnor; Malcolm North; Eugénie S. Euskirchen; Brian Oakley

2005-01-01

Little is known about biophysical controls on soil respiration in California's Sierra Nevada old-growth, 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...

A comprehensive guide to fuel management practices for dry mixed conifer forests in the northwestern United States

Treesearch

Theresa B. Jain; Mike A. Battaglia; Han-Sup Han; Russell T. Graham; Christopher R. Keyes; Jeremy S. Fried; Jonathan E. Sandquist

2012-01-01

This guide describes the benefits, opportunities, and trade-offs concerning fuel treatments in the dry mixed conifer forests of northern California and the Klamath Mountains, Pacific Northwest Interior, northern and central Rocky Mountains, and Utah. Multiple interacting disturbances and diverse physical settings have created a forest mosaic with historically low- to...

Patterns of mortality in an old-growth mixed-conifer forest of the Southern Sierra Nevada, California

Treesearch

Thomas F. Smith; David M. Rizzo; Malcolm North

2005-01-01

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...

Photo series for quantifying forest residues in the: sierra mixed conifer type, sierra true fir type.

Treesearch

W.G. Maxwell; F.R. Ward

1979-01-01

Five series of photographs display different forest residue loading levels, by size classes, for areas of like timber type (Sierra mixed conifer and Sierra true fir) and cutting objective. Information with each photo includes measured weights, volumes and other residue data, information about the timber stand and harvest actions, and assessment of fire behavior and...

Estimating past diameters of mixed conifer species in the central Sierra Nevada

Treesearch

K. Leroy Dolph

1981-01-01

Tree diameter outside bark at an earlier period of growth can be estimated from the linear relationship of present inside bark and outside bark diameters at breast height. This note presents equations for estimating inside bark diameters, outside bark diameters, and past outside bark diameters for each of the mixed-conifer species in the central Sierra Nevada.

Soil respiration response to prescribed burning and thinning in mixed-conifer and hardwood forests

Treesearch

Amy Concilio; Siyan Ma; Qinglin Li; James LeMoine; Jiquan Chen; Malcolm North; Daryl Moorhead; Randy Jensen

2005-01-01

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 hardwood forest that had undergone various...

Modeling snag dynamics in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Scott C. Vojta

2007-01-01

Snags (standing dead trees) are important components of forested habitats that contribute to ecological decay and recycling processes as well as providing habitat for many life forms. As such, snags are of special interest to land managers, but information on dynamics of snag populations is lacking. We modeled trends in snag populations in mixed-conifer and ponderosa...

Role of oaks in fisher habitat quality in the Sierra Nevada mountains at multiple spatial scales

Treesearch

Craig M. Thompson; Kathryn Purcell; Rebecca Green; Richard. Sweitzer

2015-01-01

Fishers (Pekania pennanti) occur in ponderosa pine, mixed conifer, and mixed hardwood conifer habitats in the southern Sierra Nevada at elevations from approximately 1400 to 2300 m. They are a candidate species for listing under both the Federal and California Endangered Species Acts. Since 2007, the U.S. Department of Agriculture, Forest Service (...

Changes in snag populations in northern Arizona mixed-conifer and ponderosa pine forests, 1997-2002

Treesearch

Joseph L. Ganey; Scott C. Vojta

2005-01-01

Snags (standing dead trees) are important components of forests that contribute to ecological processes and provide habitat for many life forms. We monitored dynamics of snag populations on 1-ha plots in southwestern mixed-conifer (n = 53 plots) and ponderosa pine (Pinus ponderosa, n = 60 plots) forests in north-central Arizona from 1997 to 2002. Of...

Regeneration in mixed conifer shelterwood cuttings in the Cascade Range of eastern Oregon.

Treesearch

K.W. Seidel

1979-01-01

A survey of shelterwood cuttings in mixed conifer forests in the eastern Oregon Cascade Range showed that, on the average, shelterwood units were well stocked with a mixture of advance, natural subsequent, and planted reproduction of a number of species. Because of slow invasion by understory vegetation, frequent heavy seed crops, and adequate density of the overstory...

Influence of light and soil moisture on Sierran mixed-conifer understory communities.

Treesearch

Malcolm North; Brian Oakley; Rob Fiegener; Andrew Gray; Michael Barbour

2005-01-01

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), most of which are herbs with...

Predicting surface fuel models and fuel metrics using lidar and CIR imagery in a dense mixed conifer forest

Treesearch

Marek K. Jakubowksi; Qinghua Guo; Brandon Collins; Scott Stephens; Maggi Kelly

2013-01-01

We compared the ability of several classification and regression algorithms to predict forest stand structure metrics and standard surface fuel models. Our study area spans a dense, topographically complex Sierra Nevada mixed-conifer forest. We used clustering, regression trees, and support vector machine algorithms to analyze high density (average 9 pulses/m

Characteristics of snags containing excavated cavities in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Scott C. Vojta

2004-01-01

Snags provide an important resource for a rich assemblage of cavity-nesting birds in the southwestern United States. To expand our knowledge of snag use by cavity-nesting birds in this region, we documented characteristics of snags with and without excavated cavities in mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forest in north...

Ectomycorrhizal sporophore distributions in a southeastern Appalachian mixed hardwood/conifer forest with thickets of Rhododendron maximum

Treesearch

John F. Walker; Orson R. Jr. Miller

2002-01-01

Sporophore abundance of putatively ectomycorrhizal fungi was compared in a mature mixed hardwood/conifer forest inside of (1) versus outside of (2) Rhododendron maximum thickets (RmT). Experimental blocks (1/4 ha) were established inside of (3) and outside of (3) RmT at the Coweeta Hydrologic Laboratory in Macon County, North Carolina, USA. Litter...

Mixed-conifer forests of central Oregon: Effects of logging and fire exclusion vary with environment

Treesearch

Andrew G. Merschel; Thomas A. Spies; Emily K. Heyerdahl

2014-01-01

Twentieth-century land management has altered the structure and composition of mixed-conifer forests and decreased their resilience to fire, drought, and insects in many parts of the Interior West. These forests occur across a wide range of environmental settings and historical disturbance regimes, so their response to land management is likely to vary across...

A Mixed-Effects Heterogeneous Negative Binomial Model for Postfire Conifer Regeneration in Northeastern California, USA

Treesearch

Justin S. Crotteau; Martin W. Ritchie; J. Morgan Varner

2014-01-01

Many western USA fire regimes are typified by mixed-severity fire, which compounds the variability inherent to natural regeneration densities in associated forests. Tree regeneration data are often discrete and nonnegative; accordingly, we fit a series of Poisson and negative binomial variation models to conifer seedling counts across four distinct burn severities and...

Density of large snags and logs in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Benjamin J. Bird; L. Scott Baggett; Jeffrey S. Jenness

2015-01-01

Large snags and logs provide important biological legacies and resources for native wildlife, yet data on populations of large snags and logs and factors influencing those populations are sparse. We monitored populations of large snags and logs in mixed-conifer and ponderosa pine (Pinus ponderosa) forests in northern Arizona from 1997 through 2012. We modeled density...

Coarse woody debris assay in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Scott C. Vojta

2010-01-01

Coarse woody debris (CWD) provides important ecosystem services in forests and affects fire behavior, yet information on amounts and types of CWD typically is limited. To provide such information, we sampled logs and stumps in mixed-conifer and ponderosa pine (Pinus ponderosa) forests in north-central Arizona. Spatial variability was prominent for all CWD parameters....

Trends in snag populations in Northern Arizona mixed-conifer and ponderosa pine forests, 1997-2012

Treesearch

J. L. Ganey; S. C. Vojta

2014-01-01

We monitored snag populations in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosa) forests, northern Arizona, at 5-yr intervals from 1997-2012. Snag density increased from 1997-2007 in both forest types, with accelerated change due to drought-related tree mortality during the period 2002-2007. Snag density declined non-significantly from 2007-2012,...

Predicting nitrogen flux along a vertical canopy gradient in a mixed conifer forest stand of the San Bernardino Mountains in California

Treesearch

Michael J. Arbaugh; Andrzej Bytnerowicz; Mark E. Fenn

1998-01-01

A 3-year study of nitrogenous (N) air pollution deposition to ponderosa pine (Pinus ponderosa Dougl. ex. Laws.) seedlings along a mature tree vertical canopy gradient was conducted in the mixed conifer forest of the San Bernardino Mountains of southern California. Concentrations of nitric acid vapor (HNO3), particulate nitrate...

Reality check: Shedding new light on the restoration needs of mixed-conifer forests

Treesearch

Marie Oliver; Thomas Spies; Andrew. Merschel

2014-01-01

Until recently, scientific understanding of the history and ecology of the Pacific Northwest's mixed-conifer forests east of the Cascade Range was minimal. As a result, forest managers have had limited ability to restore the health of publicly owned forests that show signs of acute stress caused by insects, disease, grazing, logging, and wildfire. A...

Relations between red alder composition and understory vegetation in young mixed forests of southeast Alaska.

Treesearch

Thomas A. Hanley; Robert L. Deal; Ewa H. Orlikowska

2006-01-01

Interest in mixed red alder (Alnus rubra Bong.)—conifer young-growth stands has grown in southeast Alaska, USA, because they appear to provide much more productive understory vegetation and wildlife habitat than do similar-aged pure conifer stands. We studied understory vegetation in nine even-aged young-growth stands (38-42 years old)...

Comparative trends in log populations in northern Arizona mixed-conifer and ponderosa pine forests following severe drought

Treesearch

Joseph L. Ganey; Scott C. Vojta

2017-01-01

Logs provide an important form of coarse woody debris in forest systems, contributing to numerous ecological processes and affecting wildlife habitat and fuel complexes. Despite this, little information is available on the dynamics of log populations in southwestern ponderosa pine (Pinus ponderosa) and especially mixed-conifer forests. A recent episode of elevated tree...

A fuel treatment reduces fire severity and increases suppression efficiency in a mixed conifer forest

Treesearch

Jason J. Moghaddas; Larry Craggs

2007-01-01

Fuel treatments are being implemented on public and private lands across the western United States. Although scientists and managers have an understanding of how fuel treatments can modify potential fire behaviour under modelled conditions, there is limited information on how treatments perform under real wildfire conditions in Sierran mixed conifer forests. The Bell...

Examining Historical and Current Mixed-Severity Fire Regimes in Ponderosa Pine and Mixed-Conifer Forests of Western North America

PubMed Central

Odion, Dennis C.; Hanson, Chad T.; Arsenault, André; Baker, William L.; DellaSala, Dominick A.; Hutto, Richard L.; Klenner, Walt; Moritz, Max A.; Sherriff, Rosemary L.; Veblen, Thomas T.; Williams, Mark A.

2014-01-01

There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of historical fire regimes in the ponderosa pine and mixed-conifer forests of western North America is therefore needed to define reference conditions and help maintain characteristic ecological diversity of these systems. We compiled landscape-scale evidence of historical fire severity patterns in the ponderosa pine and mixed-conifer forests from published literature sources and stand ages available from the Forest Inventory and Analysis program in the USA. The consensus from this evidence is that the traditional reference conditions of low-severity fire regimes are inaccurate for most forests of western North America. Instead, most forests appear to have been characterized by mixed-severity fire that included ecologically significant amounts of weather-driven, high-severity fire. Diverse forests in different stages of succession, with a high proportion in relatively young stages, occurred prior to fire exclusion. Over the past century, successional diversity created by fire decreased. Our findings suggest that ecological management goals that incorporate successional diversity created by fire may support characteristic biodiversity, whereas current attempts to “restore” forests to open, low-severity fire conditions may not align with historical reference conditions in most ponderosa pine and mixed-conifer forests of western North America. PMID:24498383

Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America.

PubMed

Odion, Dennis C; Hanson, Chad T; Arsenault, André; Baker, William L; Dellasala, Dominick A; Hutto, Richard L; Klenner, Walt; Moritz, Max A; Sherriff, Rosemary L; Veblen, Thomas T; Williams, Mark A

2014-01-01

There is widespread concern that fire exclusion has led to an unprecedented threat of uncharacteristically severe fires in ponderosa pine (Pinus ponderosa Dougl. ex. Laws) and mixed-conifer forests of western North America. These extensive montane forests are considered to be adapted to a low/moderate-severity fire regime that maintained stands of relatively old trees. However, there is increasing recognition from landscape-scale assessments that, prior to any significant effects of fire exclusion, fires and forest structure were more variable in these forests. Biota in these forests are also dependent on the resources made available by higher-severity fire. A better understanding of historical fire regimes in the ponderosa pine and mixed-conifer forests of western North America is therefore needed to define reference conditions and help maintain characteristic ecological diversity of these systems. We compiled landscape-scale evidence of historical fire severity patterns in the ponderosa pine and mixed-conifer forests from published literature sources and stand ages available from the Forest Inventory and Analysis program in the USA. The consensus from this evidence is that the traditional reference conditions of low-severity fire regimes are inaccurate for most forests of western North America. Instead, most forests appear to have been characterized by mixed-severity fire that included ecologically significant amounts of weather-driven, high-severity fire. Diverse forests in different stages of succession, with a high proportion in relatively young stages, occurred prior to fire exclusion. Over the past century, successional diversity created by fire decreased. Our findings suggest that ecological management goals that incorporate successional diversity created by fire may support characteristic biodiversity, whereas current attempts to "restore" forests to open, low-severity fire conditions may not align with historical reference conditions in most ponderosa pine and mixed-conifer forests of western North America.

Uneven-Aged Silviculture for the Loblolly and Shortleaf Pine Forest Cover Types

Treesearch

James B. Baker; Michael D. Cain; James M. Guldin; Paul A. Murphy; Michael G. Shelton

1996-01-01

The results of a half-century of experience and research with uneven-aged silviculture within the loblolly-shortleaf pine type of the Southern United States are summarized, and silvicultural guidelines for developing and managing uneven-aged stands are provided in this publication.

Forest restoration and fuels reduction in ponderosa pine and dry mixed conifer in the Southwest

Treesearch

Marlin Johnson

2008-01-01

(Please note, this is an abstract only) Most people agree that ponderosa pine and dry mixed conifer stands need to be thinned and burned to move the stands to within a normal range of variability. Unfortunately, people are in disagreement beyond that point. To some, restoration and fuels reduction means restoring stands to more open, pre-European (pre-1880) conditions...

Short-term effects of experimental burning and thinning on soil respiration in an old-growth, mixed-conifer forest

Treesearch

Siyan Ma; Jiquan Chen; Malcolm North; Heather E. Erickson; Mary Bresee; James Le Moine

2004-01-01

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...

Seasonal variation in surface fuel moisture between unthinned and thinned mixed conifer forest, northern California, USA

Treesearch

Becky L. Estes; Eric E. Knapp; Carl N. Skinner; Fabian C. C. Uzoh

2012-01-01

Reducing stand density is often used as a tool for mitigating the risk of high-intensity crown fires. However, concern has been expressed that opening stands might lead to greater drying of surface fuels, contributing to increased fire risk. The objective of this study was to determine whether woody fuel moisture differed between unthinned and thinned mixed-conifer...

Species-specific response to climate reconstruction in upper-elevation mixed-conifer forests of the western Sierra Nevada, California

Treesearch

M. Hurteau; H. Zald; M. North

2007-01-01

Dendrochronology climate reconstruction studies often sample dominant, open-grown trees to reduce competition effects and isolate annual climate influences on radial increment growth. However, there has been no examination of how species respond as stand densities increase or which species in mixed-conifer forests provide a better record of past climate. We sampled 579...

Science You Can Use Bulletin: Revisiting disturbance: A new guide for keeping dry mixed conifer forests healthy through fuel management

Treesearch

Sue Miller; Theresa Jain; Mike A. Battaglia; Han-Sup Han; Russell T. Graham; Christopher R. Keyes; Jeremy S. Fried; Jonathan E. Sandquist

2014-01-01

Planning for hazardous fuels reduction can be challenging, given that land managers must balance multiple resource objectives. To help managers with planning and implementing fuel treatments, the Rocky Mountain Research Station, with support from the Joint Fire Science Program, has published A Comprehensive Guide to Fuel Management Practices for Dry Mixed Conifer...

Modeling climate and fuel reduction impacts on mixed-conifer forest carbon stocks in the Sierra Nevada, California

Treesearch

Matthew D. Hurteau; Timothy A. Robards; Donald Stevens; David Saah; Malcolm North; George W. Koch

2014-01-01

Quantifying the impacts of changing climatic conditions on forest growth is integral to estimating future forest carbon balance. We used a growth-and-yield model, modified for climate sensitivity, to quantify the effects of altered climate on mixed-conifer forest growth in the Lake Tahoe Basin, California. Estimates of forest growth and live tree carbon stocks were...

A comprehensive guide to fuel management practices for dry mixed conifer forests in the northwestern United States: Prescribed fire

Treesearch

Theresa B. Jain; Mike A. Battaglia; Han-Sup Han; Russell T. Graham; Christopher R. Keyes; Jeremy S. Fried; Jonathan E. Sandquist

2014-01-01

Fire has had a profound historical role in shaping dry mixed conifer forests in the western United States. However, the uncertainty and complexity of prescribed fires raises the question “Is fire always the best option for treating fuels?” The decision to use prescribed fire is dependent upon several factors.

Canopy damage to conifer plantations within a large mixed-severity wildfire varies with stand age

Treesearch

Jonathan R. Thompson; Thomas A. Spies; Keith A. Olsen

2011-01-01

The 2002 Biscuit Fire burned at mixed-severities encompassing over 200,000 ha of publicly owned forestland, including more than 8300 ha of conifer plantations. We used pre- and post-fire digital aerial photography to examine how the level of canopy damage varied within these plantations in relation to topography, weather, vegetation-cover, and management history, with...

A fuel treatment reduces potential fire severity and increases suppression efficiency in a Sierran mixed conifer forest

Treesearch

Jason J. Moghaddas

2006-01-01

Fuel treatments are being widely implemented on public and private lands across the western U.S. While scientists and managers have an understanding of how fuel treatments can modify potential fire behavior under modeled conditions, there is limited information on how treatments perform under real wildfire conditions in Sierran mixed conifer forests. The Bell Fire...

Dry forest resilience varies under simulated climate‐management scenarios in a central Oregon, USA landscape.

PubMed

Halofsky, Joshua S; Halofsky, Jessica E; Burcsu, Theresa; Hemstrom, Miles A

Determining appropriate actions to create or maintain landscapes resilient to climate change is challenging because of uncertainty associated with potential effects of climate change and their interactions with land management. We used a set of climate-informed state-and-transition models to explore the effects of management and natural disturbances on vegetation composition and structure under different future climates. Models were run for dry forests of central Oregon under a fire suppression scenario (i.e., no management other than the continued suppression of wildfires) and an active management scenario characterized by light to moderate thinning from below and some prescribed fire, planting, and salvage logging. Without climate change, area in dry province forest types remained constant. With climate change, dry mixed-conifer forests increased in area (by an average of 21–26% by 2100), and moist mixed-conifer forests decreased in area (by an average of 36–60% by 2100), under both management scenarios. Average area in dry mixed-conifer forests varied little by management scenario, but potential decreases in the moist mixed-conifer forest were lower with active management. With changing climate in the dry province of central Oregon, our results suggest the likelihood of sustaining current levels of dense, moist mixed-conifer forests with large-diameter, old trees is low (less than a 10% chance) irrespective of management scenario; an opposite trend was observed under no climate change simulations. However, results also suggest active management within the dry and moist mixed-conifer forests that creates less dense forest conditions can increase the persistence of larger-diameter, older trees across the landscape. Owing to projected increases in wildfire, our results also suggest future distributions of tree structures will differ from the present. Overall, our projections indicate proactive management can increase forest resilience and sustain some societal values, particularly in drier forest types. However, opportunities to create more disturbance-adapted systems are finite, all values likely cannot be sustained at current levels, and levels of resilience success will likely vary by dry province forest type. Land managers planning for a future without climate change may be assuming a future that is unlikely to exist.

Conifer regeneration on burned and unburned clearcuts on granitic soils of the Klamath National Forest

Treesearch

Danny Heavilan

1977-01-01

Regeneration was studied on a mixed conifer stand on granitic soils on the Klamath National Forest. Six years after logging and hand planting with Douglas-fir, stocking and growth on cutblocks where slash had been broadcast burned was compared with that on similar unburned cutblocks. Conifers were seven times more plentiful on the unburned areas, the average height of...

Understory plant diversity in riparian alder-conifer stands after logging in southeast Alaska.

Treesearch

Robert L. Deal

1997-01-01

Stand structure, tree height growth, and understory plant diversity were assessed in five mixed alder-conifer stands after logging in southeast Alaska. Tree species composition ranged from 7- to 91-percent alder, and basal area ranged from 30 to 55 m2/ha. The alder exhibited rapid early height growth, but recent growth has slowed considerably. Some conifers have...

Incidence and effects of endemic populations of forest pests in young mixed-conifer forests of the Sierra Nevada

Treesearch

Carroll B. Williams; David L. Azuma; George T. Ferrell

1992-01-01

Approximately 3.200 trees in young mixed-conifer stands were examined for pest activity and human-caused or mechanical injuries, and approximately 25 percent of these trees were randomly selected for stem analyses. The examination of trees felled for stem analyses showed that 409 (47 percent) were free of pests and 466 (53 percent) had one or more pest categories....

Introduction to the special issue on Sierran mixed-conifer research

Treesearch

Malcolm North; Jiquan Chen

2005-01-01

Like much of the western United States, California’s forest has been severely altered by a century of fire suppression. The Sierra Nevada’s largest forest type, mixed conifer, which is primary habitat for more vertebrate species than any other Californian forest community, historically burned every 12–17 years. In 1894, John Muir wrote "The inviting openness of...

Soil nutrients and microbial activity after early and late season prescribed burns in a Sierra Nevada mixed conifer forest

Treesearch

Sarah T. Hamman; Ingrid C. Burke; Eric E. Knapp

2008-01-01

Restoring the natural fire regime to forested systems that have experienced fire exclusion throughout the past century can be a challenge due to the heavy fuel loading conditions. Fire is being re-introduced to mixed conifer forests in the Sierra Nevada through both early season and late season prescribed burns, even though most fires historically occurred in the late...

Fire decreases arthropod abundance but increases diversity: early and late season prescribed fire effects in a Sierra Nevada mixed-conifer forest

Treesearch

Scott M. Ferrenberg; Dylan W. Schwilk; Eric E. Knapp; Eric Groth; Jon E. Keeley

2006-01-01

Prior to fire suppression in the 20th century, the mixed-conifer forests of the Sierra Nevada, California, U.S.A., historically burned in frequent fires that typically occurred during the late summer and early fall. Fire managers have been attempting to restore natural ecosystem processes through prescription burning, and have often favored burning during the fall in...

Regeneration in United States Department of Agriculture Forest Service mixed conifer partial cuttings in the Blue Mountains of Oregon and Washington.

Treesearch

K.W. Seidel; S. Conrade. Head

1983-01-01

A survey in the Blue Mountains of north-eastern Oregon and southeastern Washington showed that, on the average, partial cuts in the grand fir/big huckleberry community were well stocked with a mixture of advance, natural post-harvest, and planted reproduction of a number of species. Partial cuts in the mixed conifer/pinegrass community had considerably fewer seedlings...

Influence of fire and El Niño on tree recruitment by Sierran mixed conifer

Treesearch

Malcolm North; Matthew Hurteau; Robert Fiegener; Michael Barbour

2005-01-01

The influence of fire and climate events on age structure of different species was examined in old-growth mixed conifer in the southern Sierra Nevada. Within a 48-ha stem-mapped sample area, after a mechanical thinning, all stumps were examined for fire scars and 526 stumps were cut to ground level and aged. Before 1865, which was the last widespread fire event, the...

Silviculture affects composition, growth, and yield in mixed northern conifers: 40-year results from the Penobscot Experimental Forest

Treesearch

Paul E. Sendak; John C. Brissette; Robert M. Frank

2003-01-01

This long-term experiment in Maine, U.S.A., was designed to provide information on the best silvicultural practices for managing stands of mixed northern conifers in northeastern U.S.A. We evaluated growth and yield and changes in species composition, quality, and structure during the first 40 years of the experiment. Replicated treatments include the selection system...

Stand density index in uneven-aged ponderosa pine stands

Treesearch

C.W. Woodall; C.E. Fiedler; K.S. Milner

2003-01-01

Stand density index (SDI) was developed to quantify relative stand density in even-aged stands. Application of SDI in uneven-aged stands has been described mathematically but not justified biologically. Diameter-class trends in SDI and sapwood area across 14 uneven-aged ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) stands in eastern...

Silvicultural systems and cutting methods for ponderosa pine forests in the Front Range of the central Rocky Mountains

Treesearch

Robert R. Alexander

1986-01-01

Guidelines are provided to help forest managers and silviculturists develop even- and/or uneven-aged cutting practices needed to convert old-growth and mixed ponderosa pine forests in the Front Range into managed stands for a variety of resource needs. Guidelines consider stand conditions, and insect and disease susceptibility. Cutting practices are designed to...

Biological and Economic Productivity of Mixed-Aged Loblolly Pine Stands in the South

Treesearch

Ronald Raunikar; Joseph Buongiorno; Jeffrey P. Prestemon; Karen Lee-Abt

1999-01-01

The financial performance of the 991 sample plots of uneven-aged loblolly-hardwood stands in the Central South FIA database examined in this report depend crucially on real price trends. Equivalent annual income (EAI) is the measure of economic performance. The regional market stumpage price data are from the Timber Mart-South database. For this set of prices, a...

Consistent definition and application of Reineke's Stand Density Index in silviculture and stand projection

Treesearch

John D. Shaw; James N. Long

2010-01-01

Reineke’s Stand Density Index (SDI) has been available to silviculturists for over 75 years, but application of this stand metric has been inconsistent. Originally described as a measurement of relative density in single-species, even-aged stands, it has since been generalized for use in uneven-aged stands and mixed-species stands. However, methods used to establish...

Disturbance From the Initial Harvest Implementing Uneven-Aged Silviculture in a Pine-Hardwood Stand in Southwestern Mississippi

Treesearch

Michael G. Shelton; Paul A. Murphy

1999-01-01

Logging disturbance is important in uneven-aged stands because harvests are frequent, merchantable trees are retained, and regeneration may be present. Logging disturbance was monitored during the establishment of a study testing the application of uneven-aged silvicufture in an irregularly aged, pine-hardwood stand. Disturbances were: (1) seedbed conditions...

Pro-B selection method for uneven-aged management of longleaf pine forests

Treesearch

Dale G. Brockway; Edward F. Loewenstein; Kenneth W. Outcalt

2015-01-01

Interest in uneven-aged silviculture has increased since advent of ecosystem management programs, which place greater emphasis on ecological values and ecosystem services while also harvesting timber from the forest. However, traditional uneven-aged approaches (e.g., BDq) are often criticized as too complex, costly, and requiring highly-trained staff. The Proportional-...

Breeding birds of even- and uneven-aged pine forests of eastern Texas

Treesearch

Ronald E. Thill; Nancy E. Koerth

2005-01-01

While single-tree selection, uneven-aged management is being used increasingly on southern national forests as an alternative to clearcutting and planting of pine, its effects on wildlife are largely unknown. We compared breeding season bird abundance, species richness, diversity, and composition among uneven-aged stands and six seral stages of even-aged stands in...

Damage and mortality assessment of redwood and mixed conifer forest types in Santa Cruz County following wildfire

Treesearch

Steve R. Auten; Nadia Hamey

2012-01-01

On August 12, 2009, the Lockheed Fire ignited the west slope of the Santa Cruz Mountains burning approximately 7,819 acres. A mixture of vegetation types were in the path of the fire, including approximately 2,420 acres of redwood forest and 1,951 acres of mixed conifer forest types representative of the Santa Cruz Mountains. Foresters and land managers were left with...

Fire-scar formation in Jeffrey pine - mixed conifer forests in the Sierra San Pedro Martir, Mexico

Treesearch

Scott L. Stephens; Danny L. Fry; Brandon M. Collins; Carl N. Skinner; Ernesto Franco-Vizcaino; Travis J. Freed

2010-01-01

Little is known about the probability of fire-scar formation. In this study, we examined all mixed conifer trees for fire-scar formation in a 16 ha watershed that burned as part of a 2003 wildfire in Sierra San Pedro Ma´rtir National Park (SSPM), Mexico. In addition, we examine the probability of fire-scar formation in relation to the previous fire interval in forests...

Fire performance in traditional silvicultural and fire and fire surrogate treatments in Sierran mixed-conifer forests: a brief summary

Treesearch

Jason J. Moghaddas; Scott L. Stephens

2007-01-01

Mixed conifer forests cover 7.9 million acres of California’s total land base. Forest structure in these forests has been influenced by harvest practices and silvicultural systems implemented since the beginning of the California Gold Rush in 1849. Today, the role of fire in coniferous forests, both in shaping past stand structure and its ability to shape future...

Natural range of variation for yellow pine and mixed-conifer forests in the Sierra Nevada, southern Cascades, and Modoc and Inyo National Forests, California, USA

Treesearch

Hugh D. Safford; Jens T. Stevens

2017-01-01

Yellow pine and mixed-conifer (YPMC) forests are the predominant montane forest type in the Sierra Nevada, southern Cascade Range, and neighboring forested areas on the Modoc and Inyo National Forests (the "assessment area"). YPMC forests occur above the oak woodland belt and below red fir forests, and are dominated by the yellow pines (ponderosa pine [

Multi-scale habitat relationships of snowshoe hares (Lepus americanus) in the mixed conifer landscape of the Northern Rockies, USA: Cross-scale effects of horizontal cover with implications for forest management

Treesearch

Joseph D. Holbrook; John R. Squires; Lucretia E. Olson; Rick L. Lawrence; Shannon L. Savage

2016-01-01

Snowshoe hares (Lepus americanus) are an ecologically important herbivore because they modify vegetation through browsing and serve as a prey resource for multiple predators. We implemented a multiscale approach to characterize habitat relationships for snowshoe hares across the mixed conifer landscape of the northern Rocky Mountains, USA. Our objectives were to (1)...

Initial tree mortality, and insect and pathogen response to fire and thinning restoration treatments in an old growth, mixed-conifer forest of the Sierra Nevada, California

Treesearch

P. Maloney; T. Smith; C. Jensen; J. Innes; D. Rizzo; M. North

2008-01-01

Fire and thinning restoration treatments in fire-suppressed forests often damage or stress leave trees, altering pathogen and insect affects. We compared types of insect- and pathogen-mediated mortality on mixed-conifer trees 3years after treatment. The number of bark beetle attacked trees was greater in burn treatments compared with no-burn treatments, and in some...

Effects of Pine and Hardwood Basal Areas After Uneven-Aged Silvicultural Treatments on Wildlife Habitat

Treesearch

Darren A. Miller; Bruce D. Leopold; L. Mike Conner; Michael G. Shelton

1999-01-01

Uneven-aged management (UEAM) is becoming increasingly popular in the southeastern United States. However, effects of UEAM on wildlife habitat have not been adequately documented. We examined response of habitat within stands of varying levels of pine and hardwood basal area under an uneven-aged managegement regime in southern Mississippi. Summer and winter trends in...

Gap-based silviculture in a sierran mixed-conifer forest: effects of gap size on early survival and 7-year seedling growth

Treesearch

Robert A. York; John J. Battles; Robert C. Heald

2007-01-01

Experimental canopy gaps ranging in size from 0.1 to 1.0 ha (0.25 to 2.5 acres) were created in a mature mixed conifer forest at Blodgett Forest Research Station, California. Following gap creation, six species were planted in a wagon-wheel design and assessed for survival after two growing seasons. Study trees were measured after seven years to describe the effect of...

Predictions of fire behavior and resistance to control: for use with photo series for the sierra mixed conifer type and the sierra true fir type.

Treesearch

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance: of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Sierra Mixed Conifer Type, Sierra True Fir Type" (Maxwell, Wayne G.; Ward, Franklin R. 1979. Gen. Tech. Rep. PNW-GTR-095. Portland, OR: U.S....

Fire-return intervals in mixed-conifer forests of the Kings River Sustainable Forest Ecosystems Project area

Treesearch

Catherine Phillips

2002-01-01

Fire-return intervals were studied on six 1.4-ha plots in a 2,070-ha study area in the Dinkey Creek watershed. Stumps in mixed-conifer forest were examined for fire scars created from 1771 to 1994, with 1873 chosen as the end of the pre-Euro-American settlement period because the rate of fire events decreased on most plots after about that year. Mean intervals from...

A comprehensive guide to fuel management practices for dry mixed conifer forests in the northwestern United States: Mechanical, chemical, and biological fuel treatment methods

Treesearch

Theresa B. Jain; Mike A. Battaglia; Han-Sup Han; Russell T. Graham; Christopher R. Keyes; Jeremy S. Fried; Jonathan E. Sandquist

2014-01-01

Several mechanical approaches to managing vegetation fuels hold promise when applied to the dry mixed conifer forests in the western United States. These are most useful to treat surface, ladder, and crown fuels. There are a variety of techniques to remove or alter all kinds of plant biomass (live, dead, or decomposed) that affect forest resilience. It is important for...

Optimal uneven-aged stocking guides: an application to spruce-fir stands in New England

Treesearch

Jeffrey H. Gove; Mark J. Ducey

2014-01-01

Management guides for uneven-aged forest stands periodically need to be revisited and updated based on new information and methods. The current silvicultural guide for uneven-aged spruce-fir management in Maine and the northeast (Frank, R.M. and Bjorkbom, J.C. 1973 A silvicultural guide for spruce-fir in the northeast. General Technical Report NE-6, Forest Service. U.S...

SouthPro : a computer program for managing uneven-aged loblolly pine stands

Treesearch

Benedict Schulte; Joseph Buongiorno; Ching-Rong Lin; Kenneth E. Skog

1998-01-01

SouthPro is a Microsoft Excel add-in program that simulates the management, growth, and yield of uneven-aged loblolly pine stands in the Southern United States. The built-in growth model of this program was calibrated from 991 uneven-aged plots in seven states, covering most growing conditions and sites. Stands are described by the number of trees in 13 size classes...

Ground-layer plant community responses to even-age and uneven-age silvicultural treatments in Wisconsin northern hardwood forests

Treesearch

Cristel C. Kern; Brian J. Palik; Terry F. Strong

2006-01-01

We evaluated ground-layer plant diversity and community composition in northern hardwood forests among uncut controls and stands managed with even-age or uneven-age silvicultural systems. Even-age treatments included diameter-limit cuttings (20-cm diameter at 30-cm stem height) in 1952 and shelterwood removals in 1964. Uneven-age treatments included three intensities...

Effects of stand and site variables on the lumber value of uneven-aged loblolly pine stands

Treesearch

David W. Patterson; Paul A. Murphy; Michael G. Shelton

2000-01-01

Uneven-aged silviculture using single-tree selection provides the landowner with periodic income from a continuous forest which has a varied canopy. Data were collected from 24 plots of a larger study to determine if site index, basal area, and maximum dbh affected volume and value of lumber from loblolly pine (Pinus taeda L.) trees in uneven-aged...

Comparison of log quality from even-aged and uneven-aged loblolly pine stands in south Arkansas

Treesearch

James M. Guldin; Michael W. Fitzpatrick

1991-01-01

Log grade, number of knots, and log volume of the first two logs, as well as form class of the butt log, were compared across three broad sawtimber categories among even-aged plantations, even-aged natural stands, and uneven-aged natural stands of loblolly pine (Pinus taeda L .) in Ashley County, AR. Trees from uneven-aged stands had butt logs of...

SDI-Flex: a new technique of allocating growing stock for developing treatment prescriptions in uneven-aged forest stands

Treesearch

Wayne D. Shepperd

2007-01-01

One of the difficulties of apportioning growing stock across diameter classes in multi- or uneven-aged forests is estimating how closely the target stocking value compares to the maximum stocking that could occur in a particular forest type and eco-region. Although the BDQ method had been used to develop uneven-aged prescriptions, it is not inherently related to any...

Optimizing management regimes for carbon storage and other benefits in uneven-aged stands dominated by Norway spruce, with a derivation of the economic supply of carbon storage

Treesearch

Joseph Buongiorno; Espen Andreas Halvorsen; Ole Martin Bollandsas; Terje Gobakken; Ole Hofstad

2012-01-01

This study sought optimal sustainable management regimes of uneven-aged Norway spruce-dominated stands with multiple objectives. The criteria were financial returns, CO2 sequestration and diversity of tree size and species. At prevailing timber prices, harvest and transport costs, and interest rates, uneven-aged management for timber alone was...

Back to the Future: Building resilience in Colorado Front Range forests using research findings and a new guide for restoration of ponderosa and dry-mixed conifer landscapes

Treesearch

Sue Miller; Rob Addington; Greg Aplet; Mike Battaglia; Tony Cheng; Jonas Feinstein; Jeff Underhill

2018-01-01

Historically, the ponderosa and dry mixed-conifer forests of the Colorado Front Range were more open and grassy, and trees of all size classes were found in a grouped arrangement with sizable openings between the clumps. As a legacy of fire suppression, today’s forests are denser, with smaller trees. Proactive restoration of this forest type will help to reduce fuel...

Influences of climate on fire regimes in montane forests of north-western Mexico

Treesearch

Carl N. Skinner; Jack H. Burk; Michael G. Barbour; Ernesto Franco-Vizcaino; Scott L. Stephens

2008-01-01

Aim To identify the influence of interannual and interdecadal climate variation on the occurrence and extent of fires in montane conifer forests of north-western Mexico. Location This study was conducted in Jeffrey pine (Pinus jeffreyi Grev. & Balf.)- dominated mixed-conifer...

An analysis of tree mortality using high resolution remotely-sensed data for mixed-conifer forests in San Diego county

NASA Astrophysics Data System (ADS)

Freeman, Mary Pyott

ABSTRACT An Analysis of Tree Mortality Using High Resolution Remotely-Sensed Data for Mixed-Conifer Forests in San Diego County by Mary Pyott Freeman The montane mixed-conifer forests of San Diego County are currently experiencing extensive tree mortality, which is defined as dieback where whole stands are affected. This mortality is likely the result of the complex interaction of many variables, such as altered fire regimes, climatic conditions such as drought, as well as forest pathogens and past management strategies. Conifer tree mortality and its spatial pattern and change over time were examined in three components. In component 1, two remote sensing approaches were compared for their effectiveness in delineating dead trees, a spatial contextual approach and an OBIA (object based image analysis) approach, utilizing various dates and spatial resolutions of airborne image data. For each approach transforms and masking techniques were explored, which were found to improve classifications, and an object-based assessment approach was tested. In component 2, dead tree maps produced by the most effective techniques derived from component 1 were utilized for point pattern and vector analyses to further understand spatio-temporal changes in tree mortality for the years 1997, 2000, 2002, and 2005 for three study areas: Palomar, Volcan and Laguna mountains. Plot-based fieldwork was conducted to further assess mortality patterns. Results indicate that conifer mortality was significantly clustered, increased substantially between 2002 and 2005, and was non-random with respect to tree species and diameter class sizes. In component 3, multiple environmental variables were used in Generalized Linear Model (GLM-logistic regression) and decision tree classifier model development, revealing the importance of climate and topographic factors such as precipitation and elevation, in being able to predict areas of high risk for tree mortality. The results from this study highlight the importance of multi-scale spatial as well as temporal analyses, in order to understand mixed-conifer forest structure, dynamics, and processes of decline, which can lead to more sustainable management of forests with continued natural and anthropogenic disturbance.

Three studies on ponderosa pine management on the Warm Springs Indian Reservation: stocking control in uneven-aged stands, forest products from fire-damage trees, and fuels reduction

Treesearch

John V. Arena

2005-01-01

Over 60,000 acres of ponderosa pine (Pinus ponderosa P. and C. Lawson) forest on the Warm Springs Indian Reservation (WSIR) in Oregon are managed using an uneven-age system. Three on-going studies on WSIR address current issues in the management of pine forests: determining levels of growing stock for uneven-age management, fire effects on wood...

Photosynthetic phenological variation may promote coexistence among co-dominant tree species in a Madrean sky island mixed conifer forest.

PubMed

Potts, D L; Minor, R L; Braun, Z; Barron-Gafford, G A

2017-09-01

Across much of western North America, forests are predicted to experience a transition from snow- to rain-dominated precipitation regimes due to anthropogenic climate warming. Madrean sky island mixed conifer forests receive a large portion of their precipitation from summertime convective storms and may serve as a lens into the future for snow-dominated forests after prolonged warming. To better understand the linkage between physiological traits, climate variation, and the structure and function of mixed conifer forests, we measured leaf photosynthetic (A) responses to controlled variation in internal CO2 concentration (Ci) to quantify interspecific phenological variation in A/Ci-derived ecophysiological traits among ponderosa pine (Pinus ponderosa Lawson and C. Lawson), southwestern white pine (Pinus strobiformis Engelm.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Species had similar, positive responses in net photosynthesis under ambient conditions (Anet) to the onset of summertime monsoonal precipitation, but during the cooler portions of the year P. ponderosa was able to maintain greater Anet than P. menziesii and P. strobiformis. Moreover, P. ponderosa had greater Anet in response to ephemerally favorable springtime conditions than either P. menziesii or P. strobiformis. Monsoonal precipitation was associated with a sharp rise in the maximum rates of electron transport (Jmax) and carboxylation (VCmax) in P. menziesii in comparison with P. ponderosa and P. strobiformis. In contrast, species shared similar low values of Jmax and VCmax in response to cool winter temperatures. Patterns of relative stomatal limitation followed predictions based on species' elevational distributions, reinforcing the role of stomatal behavior in maintaining hydraulic conductivity and shaping bioclimatic limits. Phenological variation in ecophysiologial traits among co-occurring tree species in a Madrean mixed conifer forest may promote temporal resource partitioning and thereby contribute to species' coexistence. Moreover, these results provide a physiological basis for predicting the ecological implications of North American mixed conifer forests currently transitioning from snow- to rain-dominated precipitation regimes. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Growing high quality hardwoods: Plantation trials of mixed hardwood species in Tennessee

Treesearch

Christopher M. Oswalt; Wayne K. Clatterbuck

2011-01-01

Hardwood plantations are becoming increasingly important in the United States. To date, many foresters have relied on a conifer plantation model as the basis of establishing and managing hardwood plantations. The monospecific approach suggested by the conifer plantation model does not appear to provide for the development of quality hardwood logs similar to those found...

Diagnosis of Annosus Root Disease in Mixed Conifer Forests in the Northwestern United States

Treesearch

Craig L. Schmitt

1989-01-01

Recognizing annosus root disease affecting conifers in northwestern United States forests is discussed. Field diagnosis can bemade by observing characteristic stand patterns, wood stain and decay, ectotrophic mycelium, and sporophores. Most seriously affected trees include hemlocks, grand fir, white fir and Pacific silver fir. Ponderosa pine and other true firs may...

Management of Westside Washington Conifer Stands Infected with Heterobasidion annosum

Treesearch

Elvira Young

1989-01-01

Timber stands in western Washington are managed for many purposes. Such stands yield commodity and noncommodity outputs, such as recreation, wildlife, visual resources, or watershed benefits, and often from the same stands. Annosus root disease is widespread in many mixed conifer stands within the western hemlock, mountain hemlock, and Pacific silver fir zones west of...

Contrasting spatial patterns in active-fire and fire-suppressed Mediterranean climate old-growth mixed conifer forests

Treesearch

Danny L. Fry; Scott L. Stephens; Brandon M. Collins; Malcolm North; Ernesto Franco-Vizcaino; Samantha J. Gill

2014-01-01

In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference...

Clearcutting and natural regeneration: management implications for the northern Sierra Nevada

Treesearch

Philip M. McDonald

1983-01-01

In the young-mature mixed-conifer and hardwood forests of north-central California, a dense and persistent hardwood understory competes with the conifers for space, nutrients, and water. Clear-cutting with intensive site preparation often is the most appropriate silvicultural regeneration method. This report, the result of 20 years of research on the Challenge...

Above- and below-ground effects of aspen clonal regeneration and succession to conifers

Treesearch

Wayne D. Shepperd; Dale L. Bartos; Stephen A. Mata

2001-01-01

Above- and below-ground characteristics were measured and compared for six sets of paired trembling aspen (Populus tremuloides Michx.) clones on the Fishlake National Forest in central Utah. Three self-regenerating clones were compared with three non-regenerating clones and three pure aspen stands were compared with three mixed aspen-conifer stands. Regenerating clones...

An experimental burn to restore a moth-killed boreal conifer forest, Krasnoyarsk Region, Russia

Treesearch

E.N. Valendik; J.C. Brissette; Ye. K. Kisilyakhov; R.J. Lasko; S.V. Verkhovets; S.T. Eubanks; I.V. Kosov; A. Yu. Lantukh

2006-01-01

Mechanical treatment and prescribed fire were used to restore a mixed conifer stand (Picea-Abies-Pinus) following mortality from an outbreak of Siberian moth (Dendrolimus superans sibiricus). Moth-killed stands often become dominated by Calamagrostis, a sod-forming grass. The large amount of woody debris and the sod hinder coniferous seedling establishment and...

Fuels Inventories in the Los Alamos National Laboratory Region: 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balice, R.G.; Oswald, B.P.; Martin, C.

1999-03-01

Fifty-four sites were surveyed for fuel levels, vegetational structures, and topographic characteristics. Most of the surveyed sites were on Los Alamos National Laboratory property, however, some surveys were also conducted on U.S. Forest Service property. The overall vegetation of these sites ranged from pinon-juniper woodlands to ponderosa pine forests to mixed conifer forests, and the topographic positions included canyons, mesas, and mountains. The results of these surveys indicate that the understory fuels are the greatest in mixed conifer forests and that overstory fuels are greatest in both mixed conifer forests and ponderosa pine forests on mesas. The geographic distribution ofmore » these fuels would suggest a most credible wildfire scenario for the Los Alamos region. Three major fires have occurred since 1954 and these fires behaved in a manner that is consistent with this scenario. The most credible wildfire scenario was also supported by the results of BEHAVE modeling that used the fuels inventory data as inputs. Output from the BEHAVE model suggested that catastrophic wildfires would continue to occur during any season with sufficiently dry, windy weather.« less

Conifer seedling survival under closed-canopy and manzanita patches in the Sierra Nevada

Treesearch

A. Plamboeck; M. North; T. Dawson

2008-01-01

After a century of fire suppression, prescribed fire and mechanical thinning are widely used to restore mixed-conifer forests in California’s Sierra Nevada, yet after these treatments, trees sometimes fail to regenerate on many sites, for several possible reasons. Notably, competition between shrubs and tree seedlings for scarce water during prolonged summer dry...

Shrub removal in reforested post-fire areas increases native plant species richness

Treesearch

Gabrielle N. Bohlman; Malcolm North; Hugh D. Safford

2016-01-01

Large, high severity fires are becoming more prevalent in Sierra Nevada mixed-conifer forests, largely due to heavy fuel loading and forest densification caused by past and current management practices. In post-fire areas distant from seed trees, conifers are often planted to re-establish a forest and to prevent a potential type-conversion to shrub fields. Typical...

A preliminary investigation on the feasibility of preharvest burning for shrub control

Treesearch

J. Boone Kauffman; R. E. Martin

1985-01-01

Historically, fire was a natural component in ponderosa pine (Pinus ponderosa)-mixed conifer ecosystems in the Sierra Nevada of California. Wildfires may have reduced the number of shrub seeds in the soil, as well as the density of mature shrubs and young hardwoods, thereby allowing conifers to reinvade a site after disturbance, and grow with reduced competition. With...

Historical forest structure, composition, and spatial pattern in dry conifer forests of the western Blue Mountains, Oregon

Treesearch

Derek J. Churchill; Gunnar C. Carnwath; Andrew J. Larson; Sean A. Jeronimo

2017-01-01

In frequent-fire forests of the interior Western United States, historical (prefire suppression) conditions are often used as a reference to set management objectives, guide prescriptions, and monitor treatment effectiveness. We quantified the historical size, density, composition, and spatial patterns of dry mixed-conifer forests in the Blue Mountains of Oregon to...

Environmental Assessment for Kirtland Air Force Base Arsenic Compliance System

DTIC Science & Technology

2003-09-01

Burrowing owl Athene cunicularia FSC hypugaea Mexican spotted Strix occidentalis FT,CH owl Iucida white-eared Hylocharis leucotis ST hummingbird...Kirtland AFB, their distribution range is nearby and appropriate habitat occurs on base. Mexican spotted owl The federally threatened Mexican ...conifers. In New Mexico, Mexican spotted owls occur in mixed conifer forests, ponderosa pine (Pinus ponderosa) forests, rocky canyons, and associated

Red alder-conifer stands in Alaska: An example of mixed species management to enhance structural and biological complexity

Treesearch

Robert Deal; Ewa Orlikowska; David D’Amore; Paul Hennon

2017-01-01

There is worldwide interest in managing forests to improve biodiversity, enhance ecosystem services and assure long-term sustainability of forest resources. An increasingly important goal of forest management is to increase stand diversity and improve wildlife and aquatic habitat. Well-planned silvicultural systems containing a mixture of broadleaf-conifer species have...

Long-term effects of fire severity on oak–conifer dynamics in the southern Cascades

Treesearch

Matthew I. Cocking; J. Morgan Varner; Eric E. Knapp

2014-01-01

We studied vegetation composition and structure in a mixed conifer–oak ecosystem across a range of fire severity 10 years following wildfire. Sample plots centered on focal California black oaks (Quercus kelloggii) were established to evaluate oak and neighboring tree and shrub recovery across a gradient of fire severity in the southern Cascade...

Canopy arthropod responses to thinning and burning treatments in old-growth mixed-conifer forest in the Sierra Nevada, California

Treesearch

Thomas Rambo; Timothy Schowalter; Malcolm North

2014-01-01

We compared canopy arthropod responses to common fuels reduction treatments at Teakettle Experimental Forest in the south-central Sierra Nevada of California. We sampled arthropod communities among four dominant overstory conifer species and three dominant understory angiosperm species before and after overstory or understory thinning or no thinning treatments followed...

Nitrogen mineralization in aspen/conifer soils after a natural fire

Treesearch

Michael C. Amacher; Dale L. Bartos; Tracy Christopherson; Amber D. Johnson; Debra E. Kutterer

2001-01-01

We measured the effects of the 1996 Pole Creek fire, Fishlake National Forest, Utah, on available soil N and net N mineralization for three summers after the fire using an ion exchange membrane (IEM) soil core incubation method. Fire in mixed aspen/conifer increased the amount of available NH4, and a subsequent net increase in soil nitrification was observed. Release...

Variability in vegetation and surface fuels across mixed-conifer-dominated landscapes with over 40 years of natural fire

Treesearch

Brandon M. Collins; Jamie M. Lydersen; Danny L. Fry; Katherine Wilkin; Tadashi Moody; Scott L. Stephens

2016-01-01

Studies of historical fire and vegetation conditions in dry conifer forests have demonstrated a high degree of heterogeneity across landscapes. However, there is a limit to the amount of inference that can be drawn from historical fire reconstructions. Contemporary "reference" landscapes may be able to provide information that is not available from historical...

Post-fire management regimes affect carbon sequestration and storage in a Sierra Nevada mixed conifer forest

Treesearch

Elizabeth M. Powers; John D. Marshall; Jianwei Zhang; Liang Wei

2013-01-01

Forests mitigate climate change by sequestering CO2 from the atmosphere and accumulating it in biomass storage pools. However, in dry conifer forests, fire occasionally returns large quantities of CO2 to the atmosphere. Both the total amount of carbon stored and its susceptibility to loss may be altered by post-fire land...

Soil nitrogen mineralization in a clearcutting chronosequence in a northern California conifer forest

Treesearch

D. W. Frazier; J. G. McColl; R. F. Powers

1990-01-01

Soil ammonification, nitrification, and N mobility were studied for 1 yr in three Sierra Nevada (USA) mixed-conifer stands to examine the long-term influence of timber harvesting on soil N dynamics. Clearcutting had a persistent effect on soil N mineralization, detectable by in situ incubation but not by conventional low-tension lysimetry. Mineralization rates were...

Shelterwood cutting in a young-growth, mixed-conifer stand in north central California

Treesearch

Philip M. McDonald

1976-01-01

A two-stage shelterwood cutting, at 12 trees per acre, with site preparation, enhanced seedfall, regeneration, and residual growth at the Challenge Experimental Forest, north central California. Shelterwood trees produced 9.2 times more seed than trees in the control. Ponderosa pine regeneration numbered about 3700 seedlings per acre (9139 per ha) and tolerant conifers...

Automated estimation of individual conifer tree height and crown diameter via Two-dimensional spatial wavelet analysis of lidar data

Treesearch

Michael J. Falkowski; Alistair M.S. Smith; Andrew T. Hudak; Paul E. Gessler; Lee A. Vierling; Nicholas L. Crookston

2006-01-01

We describe and evaluate a new analysis technique, spatial wavelet analysis (SWA), to automatically estimate the location, height, and crown diameter of individual trees within mixed conifer open canopy stands from light detection and ranging (lidar) data. Two-dimensional Mexican hat wavelets, over a range of likely tree crown diameters, were convolved with lidar...

Feeding ecology of sharp-shinned hawks in deciduous and coniferous forests in Colorado

Treesearch

Suzanne M. Joy; Richard T. Reynolds; Richard L. Knight; Richard W. Hoffman

1994-01-01

Feeding ecology of 11 Sharp-skinned Hawk (Accipiter striates) pairs nesting in aspen (Populus tremuloides), conifer (Abies, Picea spp.), and mixed aspen-conifer habitats in southwest Colorado was investigated during 1988-1989. Small birds (x-bar = 20.9 g, SE = 0.8 g) and mammals (x-bar = 41.1 g, SE = 3.3 g) comprised 91 and 9% of...

Harvesting Productionin Uneven-Aged Loblolly-Shortleaf Pine Stands:The Crossett Farm Forestry Forties

Treesearch

R. Kluender; B. Stokes; S. Woodfin

1992-01-01

Twostands managed using uneven-aged techniques werehar- vested aspar-t of a5-year entry schedule. Felling and skidding productivity varied significantly with average stem diameter and volume and was affected by diameter distribution of the removed material.

Canopy structure of tropical and sub-tropical rain forests in relation to conifer dominance analysed with a portable LIDAR system.

PubMed

Aiba, Shin-ichiro; Akutsu, Kosuke; Onoda, Yusuke

2013-12-01

Globally, conifer dominance is restricted to nutient-poor habitats in colder, drier or waterlogged environments, probably due to competition with angiosperms. Analysis of canopy structure is important for understanding the mechanism of plant coexistence in relation to competition for light. Most conifers are shade intolerant, and often have narrow, deep, conical crowns. In this study it is predicted that conifer-admixed forests have less distinct upper canopies and more undulating canopy surfaces than angiosperm-dominated forests. By using a ground-based, portable light detection and ranging (LIDAR) system, canopy structure was quantified for old-growth evergreen rainforests with varying dominance of conifers along altitudinal gradients (200-3100 m a.s.l.) on tropical and sub-tropical mountains (Mount Kinabalu, Malaysian Borneo and Yakushima Island, Japan) that have different conifer floras. Conifers dominated at higher elevations on both mountains (Podocarpaceae and Araucariaceae on Kinabalu and Cupressaceae and Pinaceae on Yakushima), but conifer dominance also varied with soil/substrate conditions on Kinabalu. Conifer dominance was associated with the existence of large-diameter conifers. Forests with higher conifer dominance showed a canopy height profile (CHP) more skewed towards the understorey on both Kinabalu and Yakushima. In contrast, angiosperm-dominated forests had a CHP skewed towards upper canopy, except for lowland dipterocarp forests and a sub-alpine scrub dominated by small-leaved Leptospermum recurvum (Myrtaceae) on Kinabalu. Forests with a less dense upper canopy had more undulating outer canopy surfaces. Mixed conifer-angiosperm forests on Yakushima and dipterocarp forests on Kinabalu showed similar canopy structures. The results generally supported the prediction, suggesting that lower growth of angiosperm trees (except L. recurvum on Kinabalu) in cold and nutrient-poor environments results in a sparser upper canopy, which allows shade-intolerant conifers to co-occur with angiosperm trees either as emergents or as codominants in the open canopy.

AmeriFlux US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is a pine/fir forest; it historically experienced logging and wildfire, was thinned in ~2012, and experienced severe drought and ~20% canopy mortality in 2011-15.

Determination of variability in leaf biomass densities of conifers and mixed conifers under different environmental conditions in the San Joaquin Valley air basin. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Temple, P.J.; Mutters, R.J.; Adams, C.

1995-06-01

Biomass sampling plots were established at 29 locations within the dominant vegetation zones of the study area. Estimates of foliar biomass were made for each plot by three independent methods: regression analysis on the basis of tree diameter, calculation of the amount of light intercepted by the leaf canopy, and extrapolation from branch leaf area. Multivariate regression analysis was used to relate these foliar biomass estimates for oak plots and conifer plots to several independent predictor variables, including elevation, slope, aspect, temperature, precipitation, and soil chemical characteristics.

How applicable is uneven-age management in northern forest types?

Treesearch

Stanley M. Filip

1977-01-01

For the proper application and practice of uneven-age management, one must consider residual stocking, maximum tree-size objective, and diameter distribution. All three components are described, and it is shown how they fit into a practical package for application in a timber tract.

Stand Structure and Composition 32 Years after Precommercial Thinning Treatments in a Mixed Northern Conifer Stand in Central Maine

Treesearch

Aaron R. Weiskittel; Laura S. Kenefic; Rongxia Li; John Brissette

2011-01-01

The effects of four precommercial thinning (PCT) treatments on an even-aged northern conifer stand in Maine were investigated by examining stand structure and composition 32 years after treatment. Replicated treatments applied in 1976 included: (1) control (no PCT), (2) row thinning (rowthin; 5-ft-wide row removal with 3-ft-wide residual strips), (3) row thinning with...

Black bear damage to lodgepole pine in central Oregon

USGS Publications Warehouse

Barnes, V.G.; Engeman, R.M.

1995-01-01

Black bear damage to 108 lodgepole pine trees was found in mixed conifer habitat in central Oregon. No trees of three other conifer species were injured. Eighty-nine percent of the damage occurred in the same year. Nearly 20% of the freshly damaged trees had bark removed from more than 75% of the circumference and, judging from the fate of trees damaged in prior years, probably succumbed.

Canopy structure of tropical and sub-tropical rain forests in relation to conifer dominance analysed with a portable LIDAR system

PubMed Central

Aiba, Shin-ichiro; Akutsu, Kosuke; Onoda, Yusuke

2013-01-01

Background and Aims Globally, conifer dominance is restricted to nutient-poor habitats in colder, drier or waterlogged environments, probably due to competition with angiosperms. Analysis of canopy structure is important for understanding the mechanism of plant coexistence in relation to competition for light. Most conifers are shade intolerant, and often have narrow, deep, conical crowns. In this study it is predicted that conifer-admixed forests have less distinct upper canopies and more undulating canopy surfaces than angiosperm-dominated forests. Methods By using a ground-based, portable light detection and ranging (LIDAR) system, canopy structure was quantified for old-growth evergreen rainforests with varying dominance of conifers along altitudinal gradients (200–3100 m a.s.l.) on tropical and sub-tropical mountains (Mount Kinabalu, Malaysian Borneo and Yakushima Island, Japan) that have different conifer floras. Key Results Conifers dominated at higher elevations on both mountains (Podocarpaceae and Araucariaceae on Kinabalu and Cupressaceae and Pinaceae on Yakushima), but conifer dominance also varied with soil/substrate conditions on Kinabalu. Conifer dominance was associated with the existence of large-diameter conifers. Forests with higher conifer dominance showed a canopy height profile (CHP) more skewed towards the understorey on both Kinabalu and Yakushima. In contrast, angiosperm-dominated forests had a CHP skewed towards upper canopy, except for lowland dipterocarp forests and a sub-alpine scrub dominated by small-leaved Leptospermum recurvum (Myrtaceae) on Kinabalu. Forests with a less dense upper canopy had more undulating outer canopy surfaces. Mixed conifer–angiosperm forests on Yakushima and dipterocarp forests on Kinabalu showed similar canopy structures. Conclusions The results generally supported the prediction, suggesting that lower growth of angiosperm trees (except L. recurvum on Kinabalu) in cold and nutrient-poor environments results in a sparser upper canopy, which allows shade-intolerant conifers to co-occur with angiosperm trees either as emergents or as codominants in the open canopy. PMID:24197751

Fluctuations in the East Asian monsoon recorded by pollen assemblages in sediments from the Japan Sea off the southwestern coast of Hokkaido, Japan, from 4.3 Ma to the present

NASA Astrophysics Data System (ADS)

Igarashi, Yaeko; Irino, Tomohisa; Sawada, Ken; Song, Lu; Furota, Satoshi

2018-04-01

We reconstructed fluctuations in the East Asian monsoon and vegetation in the Japan Sea region since the middle Pliocene based on pollen data obtained from sediments collected by the Integrated Ocean Drilling Program off the southwestern coast of northern Japan. Taxodiaceae conifers Metasequoia and Cryptomeria and Sciadopityacere conifer Sciadopitys are excellent indicators of a humid climate during the monsoon. The pollen temperature index (Tp) can be used as a proxy for relative air temperature. Based on changes in vegetation and reconstructed climate over a period of 4.3 Ma, we classified the sediment sequence into six pollen zones. From 4.3 to 3.8 Ma (Zone 1), the climate fluctuated between cool/moist and warm/moist climatic conditions. Vegetation changed between warm temperate mixed forest and cool temperate conifer forest. The Neogene type tree Carya recovered under a warm/moist climate. The period from 3.8 to 2.5 Ma (Zone 2) was characterized by increased Metasequoia pollen concentration. Warm temperate mixed forest vegetation developed under a cool/moist climate. The period from 2.5 to 2.2 Ma (Zone 3) was characterized by an abrupt increase in Metasequoia and/or Cryptomeria pollen and a decrease in warm broadleaf tree pollen, indicating a cool/humid climate. The Zone 4 period (2.2-1.7 Ma) was characterized by a decrease in Metasequoia and/or Cryptomeria pollen and an increase in cool temperate conifer Picea and Tsuga pollen, indicating a cool/moist climate. The period from 1.7 to 0.3 Ma (Zone 5) was characterized by orbital-scale climate fluctuations. Cycles of abrupt increases and decreases in Cryptomeria and Picea pollen and in Tp values indicated changes between warm/humid and cold/dry climates. The alpine fern Selaginella selaginoides appeared as of 1.6 Ma. Vegetation alternated among warm mixed, cool mixed, and cool temperate conifer forests. Zone 6 (0.3 Ma to present) was characterized by a decrease in Cryptomeria pollen. The warm temperate broadleaf forest and cool temperate conifer forest developed alternately under warm/moist and cold/dry climate. Zone 2 corresponded to a weak Tsushima Current breaking through the Tsushima Strait, and the beginning of orbital-scale climatic changes at 1.7 Ma during Zone 5 corresponded to the strong inflow of the Tsushima Current into the Japan Sea during interglacial periods (Gallagher et al., 2015).

Intertree competition in uneven-aged ponderosa pine stands

Treesearch

C.W. Woodall; C.E. Fiedler; K.S. Milner

2003-01-01

Intertree competition indices and effects were examined in 14 uneven-aged ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) stands in eastern Montana. Location, height, diameter at breast height (DBH), basal area increment, crown ratio, and sapwood area were determined for each tree (DBH >3.8 cm) on one stem-mapped plot...

Uneven-aged silviculture, southern style

Treesearch

James M. Guldin; James B. Baker

1998-01-01

Data spanning 60 years on uneven-aged loblolly-shortleaf pine stands in Arkansas show that two regulation methods have been successful in regulating stand development. Key attributes of these methods are that regulation is more important than balance, residual basal area drives stand development, and regeneration is the first indicator of sustainability. Marking uneven...

Managing uneven-aged stands

Treesearch

Jay R. Law; Craig G. Lorimer

1989-01-01

Maintaining uneven-aged stands involves cutting trees from a range of diameter classes in such a way that the residual stand has a balanced, steeply descending diameter distribution curve (fig. 1). The objective is to distribute trees by diameter classes so that over time the stand contains trees of different ages and sizes.

Nonlinear Programming Models to Optimize Uneven-Aged Shortleaf Pine Management

Treesearch

Benedict J. Schulte; Joseph Buongiorno

2002-01-01

Nonlinear programming models of uneven-aged shortleaf pine (Pinus echinata Mill.) management were developed to identify sustainable management regimes that optimize soil expectation value (SEV) or annual sawtimber yields. The models recognize three species groups (shortleaf pine and other softwoods, soft hardwoods and hard hardwoods) and 13 2-inch...

A Test of the Exponential Distribution for Stand Structure Definition in Uneven-aged Loblolly-Shortleaf Pine Stands

Treesearch

Paul A. Murphy; Robert M. Farrar

1981-01-01

In this study, 588 before-cut and 381 after-cut diameter distributions of uneven-aged loblolly-shortleaf pinestands were fitted to two different forms of the exponential probability density function. The left truncated and doubly truncated forms of the exponential were used.

Quantum Yields in Mixed-Conifer Forests and Ponderosa Pine Plantations

NASA Astrophysics Data System (ADS)

Wei, L.; Marshall, J. D.; Zhang, J.

2008-12-01

Most process-based physiological models require canopy quantum yield of photosynthesis as a starting point to simulate carbon sequestration and subsequently gross primary production (GPP). The quantum yield is a measure of photosynthetic efficiency expressed in moles of CO2 assimilated per mole of photons absorbed; the process is influenced by environmental factors. In the summer 2008, we measured quantum yields on both sun and shade leaves for four conifer species at five sites within Mica Creek Experimental Watershed (MCEW) in northern Idaho and one conifer species at three sites in northern California. The MCEW forest is typical of mixed conifer stands dominated by grand fir (Abies grandis (Douglas ex D. Don) Lindl.). In northern California, the three sites with contrasting site qualities are ponderosa pine (Pinus ponderosa C. Lawson var. ponderosa) plantations that were experimentally treated with vegetation control, fertilization, and a combination of both. We found that quantum yields in MCEW ranged from ~0.045 to ~0.075 mol CO2 per mol incident photon. However, there were no significant differences between canopy positions, or among sites or tree species. In northern California, the mean value of quantum yield of three sites was 0.051 mol CO2/mol incident photon. No significant difference in quantum yield was found between canopy positions, or among treatments or sites. The results suggest that these conifer species maintain relatively consistent quantum yield in both MCEW and northern California. This consistency simplifies the use of a process-based model to accurately predict forest productivity in these areas.

An Individual-Tree Growth and Yield Prediction System for Uneven-Aged Shortleaf Pine Stands

Treesearch

Michael M. Huebschmann; Lawrence R. Gering; Thomas B. Lynch; Onesphore Bitoki; Paul A. Murphy

2000-01-01

A system of equations modeling the growth and development of uneven-aged shortleaf pine (Pinus echinata Mill.) stands is described. The prediction system consists of two main components: (1) a distance-independent, individual-tree simulator containing equations that forecast ingrowth, basal-area growth, probability of survival, total and...

Silvicultural systems - uneven-aged management

Treesearch

Morris R. Wing

1977-01-01

Uneven-aged Management, to me, indicates some form of partial cutting, perhaps selective cutting or diameter limit control in the harvesting cut, which, in most cases, removes the larger diameter, more mature trees and leaves a residual stand composed of healthy, fast-growing, well-spaced second growth timber, with a good number of trees in the 6"-12"...

Does Prescribed Burning Have a Place in Regenerating Uneven-Aged Loblolly-Shortleaf Pine Stands?

Treesearch

Michael D. Cain; Michael G. Shelton

2002-01-01

Before the 1981 growing season, a study was installed in southeastern Arkansas to examine the effects of three dormant-season burn intervals (low, moderate, and high frequency) and an unburned treatment on natural regeneration in uneven-aged stands of loblolly and shortleaf pines (Pinus taeda and P. echinata, respectively)....

Regenerating uneven-aged stands of loblolly and shortleaf pines: the current state of knowledge

Treesearch

Michael G. Shelton; Michael D. Cain

2000-01-01

Periodic regeneration is crucial to creating or sustaining uneven-aged (UEA) stands of loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pines. Although both species are shade intolerant, they have silvical characteristics that are conducive to natural regeneration in UEA stands. Their seed production is fairly consistent...

Uneven-aged management of northern hardwoods in New England

Treesearch

William B. Leak; Stanley M. Filip

1975-01-01

Three main aspects of uneven-aged management in northern hardwoods are discussed: (1) choice of cutting method, including selection, group selection, and patch selection; (2) control of yields, which involves the establishment of structural goals, the control of marking operations, and the prediction of allowable harvest; and (3) the transportation or removal of...

Understory Vegetation 3 Years after Implementing Uneven-Aged Silviculture in a Shortleaf Pine-Oak Stand

Treesearch

Michael G. Shelton; Paul A. Murphy

1997-01-01

The effects of retaining overstory hardwoods on understory vegetation were determined after implementing uneven-aged silviculture usingsingle-tree selection in a shortleaf pine-oak stand (Pinus echinata Mill. and Quercus spp.) in the Ouachita Mountains. Treatments were the following hardwood basal areas (square feet per acre) and...

Structure and regrowth of longleaf pine forests following uneven-aged silviculture and hurricane disturbance at the Escambia Experimental Forest

Treesearch

Kimberly Bohn; Christel Chancy; Dale Brockway

2015-01-01

In recent decades, considerable attention has been placed on restoring and managing longleaf pine (Pinus palustris Mill.) ecosystems across the southeastern United States. Although, historically, these forests have been successfully regenerated following even-aged shelterwood reproduction methods, uneven-aged silviculture has received increasing...

Uneven-aged management of longleaf pine forests: a scientist and manager dialogue

Treesearch

Dale G. Brockway; Kenneth W. Outcalt; James M. Guldin; William D. Boyer; Joan L. Walker; D. Craig Rudolph; Robert B. Rummer; James P. Barnett; Shibu Jose; Jarek Nowak

2005-01-01

Interest in appropriate management approaches for sustaining longleaf pine (Pinus palustris Mill.) forests has increased substantially during the recent decade. Although long-leaf pine can be managed using even-aged techniques, interest in uneven-aged methods has grown significantly as a result of concern for sustaining the wide range of ecological...

A Survival Model for Shortleaf Pine Tress Growing in Uneven-Aged Stands

Treesearch

Thomas B. Lynch; Lawrence R. Gering; Michael M. Huebschmann; Paul A. Murphy

1999-01-01

A survival model for shortleaf pine (Pinus echinata Mill.) trees growing in uneven-aged stands was developed using data from permanently established plots maintained by an industrial forestry company in western Arkansas. Parameters were fitted to a logistic regression model with a Bernoulli dependent variable in which "0" represented...

What does modern technology portend for uneven-aged southern pine silviculture?

Treesearch

Don C. Bragg; Michael G. Shelton; James M. Guldin; Ernest Lovett

2004-01-01

Recent changes in forest technology and market influences may impede the practice of uneven-aged (LEA) silviculture. For example, the use of tree-length systems with mechanized harvesters can unacceptably reduce the density of advanced regeneration, making it difficult to maintain the desired size class distribution. Changes to tree utilization standards, limited...

Characteristics of gaps and natural regeneration in mature longleaf pine flatwoods ecosystems

Treesearch

Jennifer L. Gagnon; Eric J. Jokela; W.K. Moser; Dudley A. Huber

2004-01-01

Developing uneven-aged structure in mature stands of longleaf pine requires scientifically based silvicultural systems that are reliable, productive and sustainable. Understanding seedling responses to varying levels of site resource availability within forest gaps is essential for effectively converting even-aged stands to uneven-aged stands. A project was initiated...

Habitat diversity in uneven-aged northern hardwood stands: a case study

Treesearch

Laura S. Kenefic; Ralph D. Nyland

2000-01-01

Habitat characteristics were quantified in an empirically balanced uneven-aged northern hardwood stand in central New York. Canopy structure, wildlife trees, downed woody material, low cover, and richness and abundance of understory vegetation were assessed. High vertical structural diversity and low horizontal patchiness were associated with the single-tree selection...

[Vertical distribution and community diversity of butterflies in Yaoluoping National Nature Reserve, Anhui, China].

PubMed

Wang, Song; Bao, Fang-yin; Mei, Bai-mao; Ding, Shi-chao

2009-09-01

By the methods of fixed point, line intercept, and random investigation, the vertical distribution and community diversity of butterflies in Yaoluoping National Nature Reserve were investigated from 2005 to 2008. A total of 3681 specimen were collected, belonging to 111 species, 69 genera, and 10 families, among which, Nymphalidae had the higher species number, individual's number, and diversity index than the other families. The butterflies in the study area were a mixture of Oriental and Palaearetic species, with the Oriental species diminished gradually and the Palaearetic components increased gradually with increasing altitude. Among the three vertical zones ( <800 m, 800-1200 m, and >1200 m in elevation), that of 800-1200 m had the most abundant species of butterflies; and among the six habitat types (deciduous broad-leaved forest, evergreen conifer forest, conifer-broad leaf mixed forest, bush and secondary forest, farmland, and residential area), bush and secondary forest had the higher species number, individual's number, and diversity index of butterflies, while farmland had the lowest diversity index. The similarity coefficient of butterfly species between the habitats was mainly dependent on vegetation type, i.e., the more the difference of vegetation type, the lesser the species similarity coefficient between the habitats, which was the highest (0.61) between conifer-broad leaf mixed forest and bush and secondary forest, and the lowest (0. 20) between evergreen conifer forest and bush and secondary forest.

Quantifying thermal constraints on carbon and water fluxes in a mixed-conifer sky island ecosystem

NASA Astrophysics Data System (ADS)

Braun, Z.; Minor, R. L.; Potts, D. L.; Barron-Gafford, G. A.

2012-12-01

Western North American forests represent a potential, yet uncertain, sink for atmospheric carbon. Revealing how predicted climatic conditions of warmer temperatures and longer inter-storm periods of moisture stress might influence the carbon status of these forests requires a fuller understanding of plant functional responses to abiotic stress. While data related to snow dominated montane ecosystems has become more readily available to parameterize ecosystem function models, there is a paucity of data available for Madrean sky island mixed-conifer forests, which receive about one third of their precipitation from the North American Monsoon. Thus, we quantified ecophysiological responses to moisture and temperature stress in a Madrean mixed-conifer forest near Tucson, Arizona, within the footprint of the Mt. Bigelow Eddy Covariance Tower. In measuring a series of key parameters indicative of carbon and water fluxes within the dominant species across pre-monsoon and monsoon conditions, we were able to develop a broader understanding of what abiotic drivers are most restrictive to plant performance in this ecosystem. Within Pinus ponderosa (Ponderosa Pine), Pseudotsuga menziesii (Douglas Fir), and Pinus strobiformis (Southwestern White Pine) we quantified: (i) the optimal temperature (Topt) for maximum photosynthesis (Amax), (ii) the range of temperatures over which photosynthesis was at least 50% of Amax (Ω50), and (iii) each conifer's water use efficiency (WUE) to relate to the balance between carbon uptake and water loss in this high elevation semiarid ecosystem. Our findings support the prediction that photosynthesis decreases under high temperatures (>30°C) among the three species we measured, regardless of soil moisture status. However, monsoon moisture reduced sensitivity to temperature extremes and fluctuations (Ω50), which substantially magnified total photosynthetic productivity. In particular, wet conditions enhanced Amax the most dramatically for P. menziesii, elevating rates by 590%, while Ω50 grew most substantially for P. strobifomis (by 180%). Interspecific differences in temperature optima (Topt) elucidated possible species dominance predictions for seasonal and gradual temperature changes. P. menziesii may out-perform the pine species in the event that temperatures rise in conjunction with abundant summer moisture. However, if monsoon rains fail to accumulate, P. menziesii may remain at subsistence levels of photosynthesis. Together, these data will enable the parameterization of models to approximate the productivity and, ultimately, the composition of Madrean sky island mixe d-conifer forests under forecasted climate conditions of increased temperatures and more frequent drought.

A comparison of dynamic and static economic models of uneven-aged stand management

Treesearch

Robert G. Haight

1985-01-01

Numerical techniques have been used to compute the discrete-time sequence of residual diameter distributions that maximize the present net worth (PNW) of harvestable volume from an uneven-aged stand. Results contradicted optimal steady-state diameter distributions determined with static analysis. In this paper, optimality conditions for solutions to dynamic and static...

Sugar maple height-diameter and age-diameter relationships in an uneven-aged northern hardwood stand

Treesearch

Laura S. Kenefic; R.D. Nyland

1999-01-01

Sugar maple (Acer saccharum Marsh.) height-diameter and age-diameter relationships are explored in a balanced uneven-aged northern hardwood stand in central New York. Results show that although both height and age vary considerably with diameter, these relationships can be described by statistically valid equations. The age-diameter relationship...

Best density and structure for uneven-aged northern hardwood management in New England

Treesearch

William B. Leak

2003-01-01

Choice of the best residual density (basal area per acre) and structure (diameter distribution) for uneven-aged management of northern hardwoods is a complex decision that depends on the manager's decision rules, product objectives, site conditions, and - perhaps most important - current stand conditions. In contrast to other recommendations on residual density...

Optimizing the sequence of diameter distributions and selection harvests for uneven-aged stand management

Treesearch

Robert G. Haight; J. Douglas Brodie; Darius M. Adams

1985-01-01

The determination of an optimal sequence of diameter distributions and selection harvests for uneven-aged stand management is formulated as a discrete-time optimal-control problem with bounded control variables and free-terminal point. An efficient programming technique utilizing gradients provides solutions that are stable and interpretable on the basis of economic...

Model forest landscape change in the Missouri Ozarks under alternative management practices

Treesearch

Stephen R. Shifley; Frank R. Thompson; David R. Larsen; William D. Dijak

2000-01-01

We used a spatially explicit landscape model, LANDIS, to simulate the effects of five management alternatives on a 3216 ha forest landscape in southeast Missouri, USA. We compared management alternatives among two intensities of even-aged management with clearcutting, uneven-aged management with group selection harvest, a mixture of even- and uneven-aged management,...

Forest ingrowth prediction model for the Northeastern United States

Treesearch

Linda S. Gribko

1997-01-01

In the last 20 years, there has been a revival of interest in the use of uneven-aged forest management techniques in the production of timber and forest amenity values. Uneven-aged management is coming into renewed favor especially among non-industrial private landowners in the northeastern United States. The practice allows periodic timber removals on relatively small...

Uneven-aged silviculture of longleaf pine

Treesearch

James M. Guldin

2006-01-01

The use of uneven-aged silviculture has increased markedly in the past 20 years. This is especially true in the southern United States, where the use of clearcutting and planting is often viewed as a practice whose emphasis on fiber production results in unacceptable consequences for other values, such as those that benefit from maintenance of continuous forest cover...

Economic considerations of uneven-age hardwood management

Treesearch

H. Clay Smith; Gary W. Miller

1987-01-01

Uneven-age management or partial cutting methods as described in this paper allow foresters to manage eastern hardwood stands and harvest forest products without clearcutting. These methods can involve regular periodic harvests, at least for the short term, based on stand conditions and growing-site capabilities. We are not going to make the decision as to which is the...

Nonlinear programming models to optimize uneven-aged loblolly pine management

Treesearch

Benedict J. Schulte; Joseph. Buongiorno; Kenneth Skog

1999-01-01

Nonlinear programming models of uneven-aged loblolly pine (Pinus taeda L.) management were developed to identify sustainable management regimes which optimize: 1) soil expectation value (SEV), 2) tree diversity, or 3) annual sawtimber yields. The models use the equations of SouthPro, a site- and density-dependent, multi-species matrix growth and yield model that...

Regeneration patterns of a long-lived dominant conifer and the effects of logging in southern South America

NASA Astrophysics Data System (ADS)

Souza, Alexandre F.; Forgiarini, Cristiane; Longhi, Solon Jonas; Brena, Doádi Antônio

2008-09-01

The regeneration ecology of the long-lived conifer Araucaria angustifolia was studied in São Francisco de Paula, southern Brazil. We evaluated the expectations that: (i) size distribution of populations of Araucaria angustifolia, a large conifer that dominates southern Brazil's mixed forests, is left-skewed in old-growth forests but right-skewed in logged forests, indicating chronic recruitment failure in the first kind of habitat as well as a recruitment pulse in the second; (ii) seedlings and juveniles are found under more open-canopy microsites than would be expected by chance; and (iii) reproductive females would be aggregated at the coarse spatial scales in which past massive recruitment events are expected to have occurred, and young plants would be spatially associated with females due to the prevalence of vertebrate and large-bird seed dispersers. Data were collected in the threatened mixed conifer-hardwood forests in southern Brazil in ten 1-ha plots and one 0.25-ha plot that was hit by a small tornado in 2003. Five of these plots corresponded to unlogged old-growth forests, three to forests where A. angustifolia was selectively logged ca. 60 years ago and two to forests selectively logged ca. 20 years ago. For the first time, ontogenetic life stages of this important conifer are identified and described. The first and second expectations were fulfilled, and the third was partially fulfilled, since seedlings and juveniles were hardly ever associated with reproductive females. These results confirm the generalization of the current conceptual model of emergent long-lived pioneer regeneration to Araucaria angustifolia and associate its regeneration niche to the occupation of large-scale disturbances with long return times.

Harvest impacts in uneven-aged and even-aged Missouri Ozark forests

Treesearch

John P. Dwyer; Daniel C. Dey; William D. Walter; Randy G. Jensen

2004-01-01

Forest managers are concerned about the potential damage to residual trees and site from cyclic harvest re-entries into the same forest stand. This study summarizes logging and felling damage resulting from the harvesting of silvicultural treatments on a large landscape experiment in southern Missouri that is designed to compare impacts of even-aged, uneven-aged and no...

Conversion of Successionally Stable Even-Aged Oak Stands to an Uneven-Aged Structure

Treesearch

Edward F. Loewenstein; James M. Guldin

2004-01-01

Developing a silvicultural prescription to convert an even-aged or unmanaged oak stand to an uneven-aged structure depends in large part on the length of time the existing overstory will live. Four conversion prescriptions, representing three initial stand conditions, are presented. Each prescription partitions the cut of the original overstory differently in time and...

The development of uneven-aged southern pine silviculture before the Crossett Experimental Forest (Arkansas, USA)

Treesearch

Don C. Bragg

2017-01-01

Although the Crossett Experimental Forest (CEF) played a well-publicized role in the development of uneven-aged southern pine silviculture, work on a selection method in Arkansas (USA) did not originate there. In 1925, Leslie Pomeroy and Eugene Connor acquired the Ozark Badger Lumber Company and initiated an expert-driven selection management system compatible with...

Uneven-aged silviculture in cedar-hemlock-grand fir ecosystems of the northern Rocky Mountains

Treesearch

Russell T. Graham; Theresa B. Jain; Jonalea R. Tonn

1999-01-01

Uneven-aged silviculture is used infrequently in the Northern Rocky Mountains. Because of wildlife, watershed, or scenic issues it is often preferred for managing many stands. While it has been applied in the ponderosa pine (Pinus ponderosa) forests it has had limited application in the grand fir (Abies grandis)-westem redcedar (Thuja plicate)-westem hemlock (Tsuga...

Preliminary thinning guidelines using stand density index for the maintenance of uneven-aged pinyon-juniper ecosystems

Treesearch

Douglas H. Page

2008-01-01

This paper demonstrates how Stand Density Index may be used to guide postthinning stand structure for the sustainable management of pinyon-juniper ecosystems. The post-thinning residual stand density can be varied to achieve various management objectives. Uneven-aged management is recommended, where possible, as a better approximation of the natural development process...

The silvicultural implications of age patterns in two southern pine stands after 72 years of uneven-aged management

Treesearch

Don C. Bragg; James M. Guldin

2015-01-01

A randomized sample of 250 loblolly (Pinus taeda L.) and shortleaf (Pinus echinata Mill.) pine ring counts was collected from the Good and Poor Farm Forestry compartments on the Crossett Experimental Forest. These mature, pine-dominated stands have been managed using uneven-aged silviculture since 1937. Our sample shows that both...

Rotated sigmoid structures in managed uneven-aged northern hardwood stands: a look at the Burr Type III distribution

Treesearch

Jeffrey H. Gove; Mark J. Ducey; William B. Leak; Lianjun Zhang

2008-01-01

Stand structures from a combined density manipulation and even- to uneven-aged conversion experiment on the Bartlett Experimental Forest (New Hampshire, USA) were examined 25 years after initial treatment for rotated sigmoidal diameter distributions. A comparison was made on these stands between two probability density functions for fitting these residual structures:...

Diameter Growth in Even- and Uneven-Aged Northern Hardwoods in New Hampshire Under Partial Cutting

Treesearch

William B. Leak

2004-01-01

One important concern in the conversion of even-aged stands to an uneven aged condition through individual-tree or small-group cutting is the growth response throughout the diameter-class distribution, especially of the understoty trees Increment-core sampling of an older, uneven-aged northern hardwood stand in New Hampshire under management for about 50 years...

Effects of uneven-aged and diameter-limit management on West Virginia tree and wood quality

Treesearch

Michael C. Wiemann; Thomas M. Schuler; John E. Baumgras

2004-01-01

Uneven-aged and diameter-limit management were compared with an unmanaged control on the Fernow Experimental Forest near Parsons, West Virginia, to determine how treatment affects the quality of red oak (Quercus rubra L.), sugar maple (Acer saccharum Marsh.), and yellow-poplar (Liriodendron tulipifera L.). Periodic harvests slightly increased stem lean, which often...

A better way - uneven-aged management of southern yellow pine

Treesearch

Don M. Handley; Joshua C. Dickinson

2013-01-01

Uneven-aged management of southern yellow pine offers family forest owners in the Coastal Plain and Piedmont of the Southeast an attractive economic alternative to the two most common forestry scenarios. First, the great majority of owners practice no management. Too often they call in a timber buyer or procurement forester who high grades the forest. Second are the...

20 years of intensive uneven-aged management: Effect on Growth, Yield, and Species Composition in Two hardwood Stands in West Virginia

Treesearch

George R., Jr. Trimble; George R. Trimble

1970-01-01

In 1948 a study of uneven-aged forest management, with individual tree-selection cuttings, was begun on two 31-acre stands of Appalachian hardwoods in West Virginia. Now, after 20 years, these stands are beginning to show how this kind of management affects growth, yield, and species composition.

Estimating Chemical Exchange between Atmospheric Deposition and Forest Canopy in Guizhou, China.

PubMed

Li, Wei; Gao, Fang; Liao, Xueqin

2013-01-01

To evaluate the effects of atmospheric deposition on forest ecosystems, wet-only precipitation and throughfall samples were collected in two forest types (Masson pine [ Lamb.] forests and mixed conifer and broadleaf forests) in the Longli forest in the Guizhou province of southwestern China for a period of 21 successive months from April 2007 to December 2008. The pH and chemical components of precipitation and throughfall were analyzed. In addition, the canopy budget model was applied to distinguish between in-canopy and atmospheric sources of chemical compounds. Canopy leaching and total potentially acidifying deposition fluxes were calculated. The results showed that the average pH and the concentration of ions in throughfall were higher than those in precipitation, with the exception of the NH concentration. Dry deposition of S and N accumulated more in Masson pine forests than in mixed conifer and broadleaf forests. Canopy leaching was the most significant source of base cations in forest throughfall, which was higher in the mixed forests than in the coniferous forests. Anions in throughfall deposition in Masson pine forests exceeded those in the mixed forests. Higher total potentially acidifying deposition fluxes reflected the more effective amounts of acid delivered to Masson pine forests compared with mixed conifer and broadleaf forests. In addition, acid deposition induced the leaching and loss of nutrient ions such as Mg, K, and Ca. Although the trees of the studied areas have not shown any symptoms of cation loss, a potentially harmful influence was engendered by atmospheric deposition in the two forest types in the Longli area. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Development of the mixed conifer forest in northern New Mexico and its relationship to Holocene environmental change

NASA Astrophysics Data System (ADS)

Anderson, R. Scott; Jass, Renata B.; Toney, Jaime L.; Allen, Craig D.; Cisneros-Dozal, Luz M.; Hess, Marcey; Heikoop, Jeff; Fessenden, Julianna

2008-03-01

Chihuahueños Bog (2925 m) in the Jemez Mountains of northern New Mexico contains one of the few records of late-glacial and postglacial development of the mixed conifer forest in southwestern North America. The Chihuahueños Bog record extends to over 15,000 cal yr BP. An Artemisia steppe, then an open Picea woodland grew around a small pond until ca. 11,700 cal yr BP when Pinus ponderosa became established. C/N ratios, δ13C and δ15N values indicate both terrestrial and aquatic organic matter was incorporated into the sediment. Higher percentages of aquatic algae and elevated C/N ratios indicate higher lake levels at the opening of the Holocene, but a wetland developed subsequently as climate warmed. From ca. 8500 to 6400 cal yr BP the pond desiccated in what must have been the driest period of the Holocene there. C/N ratios declined to their lowest Holocene levels, indicating intense decomposition in the sediment. Wetter conditions returned after 6400 cal yr BP, with conversion of the site to a sedge bog as groundwater levels rose. Higher charcoal influx rates after 6400 cal yr BP probably result from greater biomass production rates. Only minor shifts in the overstory species occurred during the Holocene, suggesting that mixed conifer forest dominated throughout the record.

Development of the mixed conifer forest in northern New Mexico and its relationship to Holocene environmental change

USGS Publications Warehouse

Anderson, R. Scott; Jass, R.B.; Toney, J.L.; Allen, Craig D.; Cisneros-Dozal, L. M.; Hess, M.; Heikoop, Jeff; Fessenden, J.

2008-01-01

Chihuahueños Bog (2925 m) in the Jemez Mountains of northern New Mexico contains one of the few records of late-glacial and postglacial development of the mixed conifer forest in southwestern North America. The Chihuahueños Bog record extends to over 15,000 cal yr BP. AnArtemisiasteppe, then an openPiceawoodland grew around a small pond until ca. 11,700 cal yr BP whenPinus ponderosabecame established. C/N ratios,δ 13C andδ 15N values indicate both terrestrial and aquatic organic matter was incorporated into the sediment. Higher percentages of aquatic algae and elevated C/N ratios indicate higher lake levels at the opening of the Holocene, but a wetland developed subsequently as climate warmed. From ca. 8500 to 6400 cal yr BP the pond desiccated in what must have been the driest period of the Holocene there. C/N ratios declined to their lowest Holocene levels, indicating intense decomposition in the sediment. Wetter conditions returned after 6400 cal yr BP, with conversion of the site to a sedge bog as groundwater levels rose. Higher charcoal influx rates after 6400 cal yr BP probably result from greater biomass production rates. Only minor shifts in the overstory species occurred during the Holocene, suggesting that mixed conifer forest dominated throughout the record.

Growth model for uneven-aged loblolly pine stands : simulations and management implications

Treesearch

C.-R. Lin; J. Buongiorno; Jeffrey P. Prestemon; K. E. Skog

1998-01-01

A density-dependent matrix growth model of uneven-aged loblolly pine stands was developed with data from 991 permanent plots in the southern United States. The model predicts the number of pine, soft hardwood, and hard hardwood trees in 13 diameter classes, based on equations for ingrowth, upgrowth, and mortality. Projections of 6 to 10 years agreed with the growth...

Age structure of a southern pine stand following 72 years of uneven-aged silviculture

Treesearch

Don C. Bragg

2012-01-01

Work on uneven-aged silviculture in southern pine stands on the Crossett Experimental Forest (CEF) began in the 1930s, when a number of 16.2-ha compartments were placed into a series of demonstration projects and studies (Reynolds 1980). Two of these compartments, the Good and Poor Farm Forestry Forties, have been maintained continuously in this silvicultural regime...

Diameter growth of trees in an uneven-aged oak forest in the Missouri Ozarks

Treesearch

Edward F. Loewenstein; Paul S. Johnson; Harold E. Garrett

1997-01-01

We tested the efficacy of even-aged stand tables for predicting diameter growth of trees in uneven-aged oak stands. The study was based on the age- and diameter-structure of the Pioneer Forest, a 156,000-acre, privately owned oak forest in the Ozark Highlands of Missouri. The forest has been managed by single-tree selection since 1954.

Growth of loblolly pine stands after the first five years of uneven-aged silviculture using single-tree selection

Treesearch

Paul A. Murphy; Michael G. Shelton

1994-01-01

The effects of three levels of residual basal area (40, 60, and 80 ft2/ac), maximum dbh (12, 16, 20 in.) and site index (90 ft) on the growth of loblolly pine (Pinus taeda L.) stands after 5 yr of uneven-aged silviculture were determined from plots located in the south Arkansas and north...

Short-Term Effects of Understory and Overstory Management on Breeding Birds in Arkansas Oak-Hickory Forests

Treesearch

Paul G. Rodewald; Kimberly G. Smith

1998-01-01

Relatively little is known about the effects of uneven-aged forest management practices on eastern forest birds, despite the fact that such methods are now commonly practiced. In 1993-94, we studied the short-term effects of uneven-aged forest management on bird communities in oak-hickory forests of north-western Arkansas. We estimated bird abundance in mature forests...

Immediate, landscape-scale impacts of even-aged and uneven-aged forest management on herpetofaunal communities of the Missouri Ozark Forest Ecosystem Project

Treesearch

Rochelle B. Renken; Debby K. Frantz

2002-01-01

We examined the immediate, landscape-scale impacts of even-aged and uneven-aged forest management on the species composition, species richness, and relative abundance of herpetofaunal communities and selected focal groups of species during the second and third years following initial tree harvest on Missouri Ozark Forest Ecosystem Project (MOFEP) sites in southern...

The Plantation Conversion Demonstration at the Crossett Experimental Forest--Implications For Converting Stands From Even-Aged to Uneven-Aged Structure

Treesearch

James M. Guldin; Robert M. Farrar

2002-01-01

In the absence of replicated studies, we used a case study demonstration to illustrate converting a 26-year-old even-aged loblolly pine (Pinus taeda L.) plantation to uneven-aged structure. Unreplicated treatments included maintaining even-aged structure through low thinning (thinning from below) to a residual basal area of 80 square feet per acre,...

Forest management strategy affects saproxylic beetle assemblages: A comparison of even and uneven-aged silviculture using direct and indirect sampling.

PubMed

Joelsson, Klara; Hjältén, Joakim; Gibb, Heloise

2018-01-01

Management of forest for wood production has altered ecosystem structures and processes and led to habitat loss and species extinctions, worldwide. Deadwood is a key resource supporting forest biodiversity, and commonly declines following forest management. However, different forest management methods affect dead wood differently. For example, uneven-aged silviculture maintains an age-stratified forest with ongoing dead wood production, while even-aged silviculture breaks forest continuity, leading to long periods without large trees. We asked how deadwood-dependent beetles respond to different silvicultural practices and if their responses depend on deadwood volume, and beetles preference for decay stages of deadwood. We compared beetle assemblages in five boreal forest types with different management strategies: clearcutting and thinning (both representing even-aged silviculture), selective felling (representing uneven-aged silviculture), reference and old growth forest (both uneven-aged controls without a recent history [~50 years] of management, but the latter with high conservation values). We collected beetles using window traps and by sieving the bark from experimental logs (bolts). Beetle assemblages on clear-cuts differed from all other stand types, regardless of trapping method or decay stage preference. Thinning differed from reference stands, indicating incomplete recovery after clear-cutting, while selective felling differed only from clear-cuts. In contrast to our predictions, early and late successional species responded similarly to different silvicultural practices. However, there were indications of marginal assemblage differences both between thinned stands and selective felling and between thinned and old growth stands (p = 0.10). The stand volume of early decay stage wood influenced assemblage composition of early, but not late successional species. Uneven-aged silviculture maintained species assemblages similar to those of the reference and old growth stands and might therefore be a better management option when considering biodiversity conservation.

Experience with the selection method in pine stands in the southern United States, with implications for future application

Treesearch

James M. Guldin

2011-01-01

The selection method applied in shade-intolerant pine stands in the southern United States has been shown to be an effective method of uneven-aged silviculture, but it is becoming less frequently practiced for a variety of reasons. Economically, the high value of standing timber puts fully stocked uneven-aged pine stands at risk of liquidation if the timberland is sold...

Using FORSEE and continuous forest inventory information to evaluate implementation of uneven-aged management in Santa Cruz County coast redwood forests

Treesearch

Douglas D. Piirto; Scott Sink; Dominic Ali; Steve Auten; Christopher Hipkin; Reid. Cody

2012-01-01

Swanton Pacific Ranch in northern Santa Cruz County has been owned and managed by California Polytechnic State University (Cal Poly) Foundation since 1987. The California Forest Practice Rules specific to Santa Cruz County limit harvest rate and opening size. Cal Poly forest managers are implementing uneven-aged forest management on 1,182 acres of 80 to 110...

WestPro: a computer program for simulating uneven-aged Douglas-fir stand growth and yield in the Pacific Northwest.

Treesearch

Rebecca Ralston; Joseph Buongiorno; Benedict Schulte; Jeremy Fried

2003-01-01

WestPro is an add-in program designed to work with Microsoft Excel to simulate the growth of uneven-aged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Pacific Northwest region of the United States. Given the initial stand state, defined as the number of softwood and hardwood trees per acre by diameter class, WestPro predicts the...

A finite mixture of two Weibull distributions for modeling the diameter distributions of rotated-sigmoid, uneven-aged stands

Treesearch

Lianjun Zhang; Jeffrey H. Gove; Chuangmin Liu; William B. Leak

2001-01-01

The rotated-sigmoid form is a characteristic of old-growth, uneven-aged forest stands caused by past disturbances such as cutting, fire, disease, and insect attacks. The diameter frequency distribution of the rotated-sigmoid form is bimodal with the second rounded peak in the midsized classes, rather than a smooth, steeply descending, monotonic curve. In this study a...

A 9-year comparison of hardwood control treatments for enhancing natural regeneration and growth of loblolly-shortleaf pines in an uneven-aged stand

Treesearch

Michael D. Cain

1998-01-01

Preharvest control of hardwoods facilitated natural regeneration of loblolly and shortleaf pines (Pinus taeda L. and P. enchinata Mill.) in an overstocked, uneven-aged stand in southern Arkansas. During spring 1983, hardwoods were controlled by either basal injection of Tordon® 101R, soil application of Velpar® L, or rotary mowing...

A Matrix Transition Model for an Uneven-Aged, Oak-Hickory Forest in the Missouri Ozark Highlands

Treesearch

James R. Lootens; David R. Larsen; Edward F. Loewenstein

1999-01-01

We present a matrix growth model for an uneven-aged, oak-hickory forest in the Ozark Highlands of Missouri. The model was developed to predict ingrowth, growth of surviving trees, and mortality by diameter class for a five-year period. Tree removal from management activities is accounted for in the model. We evaluated a progression of models from a static, fixed-...

A matrix transition model for an uneven-aged, oak-hickory forest in the Missouri ozark highlands

Treesearch

James R. Lootens; David R. Larsen; Edward F. Loewenstein

1999-01-01

We presented a matrix growth model for an uneven-aged, oak-hickory forest in the Ozark Highlands of Missouri. The model was developed to predict ingrowth, growth of surviving trees, and mortality by diameter class for a five-year period. Tree removal from management activities is accounted for in the model. We evaluated a progression of models from a static, fixed...

Stump sprouting potential of oaks in Missouri Ozark forests managed by even- and uneven-aged silviculture

Treesearch

Daniel C. Dey; Randy G. Jensen

2002-01-01

We evaluated the stump sprouting potential of white oak, black oak, and scarlet oak in relation to tree age, stem diameter, and overstory density in Ozark forests managed by even-aged and uneven-aged silvicultural systems. In eastern North America, few studies have evaluated the influence of a forest canopy on the potential of hardwood stumps to sprout and contribute...

Effects of Market Prices and Silvicultural Practices on Lumber Value of Standing Trees In Uneven-Ages Plots

Treesearch

David W. Patterson

1998-01-01

Uneven-aged management plots were established using three variables (site index, basal area, and maximum diameter). This study looked at the significance of the variables on the lumber volume per acre, lumber value per thousand board feet (Mbf), and stand value per acre as well as the influence on these analysis by market prices (May 1997, May 1998, and October 1998)....

Hardwood Control Treatments to Enhance Natural Regeneration and Growth of Loblolly-Shortleaf Pines in an Uneven-Aged Stand: 12-Year Results

Treesearch

Michael D. Cain

1999-01-01

To facilitate natural regeneration of loblolly (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) in an overstocked, uneven-aged pine stand in southeastern Arkansas, hardwoods were controlled by either basal injection of Tordon® 101 R, soil application of Velpar® L, or rotary mowing followed by a broadcast spray of Tordon®...

Prescribed fire effects on structure in uneven-aged stands of loblolly and shortleaf pines

Treesearch

Michael D. Cain; T. Bently Wigley; Derik J. Reed

1998-01-01

Structure was assessed in uneven-aged stands of loblolly (Pinus taeda) and shortleaf pine (P. echinata) that were subjected to prescribed winter burns on cycles of 0, 3, 6, and 9 years. Vegetation assessments were made in late summer of 1990, 10 years after a single hardwood control treatment (basal injection of non-pine woody plants >2.5 cm in groundline diameter...

Woody vegetation following even-aged, uneven-aged, and no-harvest treatments on the Missouri Ozark Forest Ecosystem Project Sites

Treesearch

John M. Kabrick; Randy G. Jensen; Stephen R. Shifley; David R. Larsen

2002-01-01

The Missouri Ozark Forest Ecosystem Project (MOFEP) experimentally tests forest ecosystem response to (a) even-aged management with clearcutting, (b) uneven-aged management with single-tree and group selection, and (c) no-harvesting. The nine MOFEP experimental sites in the southeast Missouri Ozarks are small landscapes ranging from 772 ac (312 ha) to 1,271 ac (514 ha...

Mixed-conifer forests of central Oregon: effects of logging and fire exclusion vary with environment.

PubMed

Merschel, Andrew G; Spies, Thomas A; Heyerdahl, Emily K

Twentieth-century land management has altered the structure and composition of mixed-conifer forests and decreased their resilience to fire, drought, and insects in many parts of the Interior West. These forests occur across a wide range of environmental settings and historical disturbance regimes, so their response to land management is likely to vary across landscapes and among ecoregions. However, this variation has not been well characterized and hampers the development of appropriate management and restoration plans. We identified mixed-conifer types in central Oregon based on historical structure and composition, and successional trajectories following recent changes in land use, and evaluated how these types were distributed across environmental gradients. We used field data from 171 sites sampled across a range of environmental settings in two subregions: the eastern Cascades and the Ochoco Mountains. We identified four forest types in the eastern Cascades and four analogous types with lower densities in the Ochoco Mountains. All types historically contained ponderosa pine, but differed in the historical and modern proportions of shade-tolerant vs. shade-intolerant tree species. The Persistent Ponderosa Pine and Recent Douglas-fir types occupied relatively hot–dry environments compared to Recent Grand Fir and Persistent Shade Tolerant sites, which occupied warm–moist and cold–wet environments, respectively. Twentieth-century selective harvesting halved the density of large trees, with some variation among forest types. In contrast, the density of small trees doubled or tripled early in the 20th century, probably due to land-use change and a relatively cool, wet climate. Contrary to the common perception that dry ponderosa pine forests are the most highly departed from historical conditions, we found a greater departure in the modern composition of small trees in warm–moist environments than in either hot–dry or cold–wet environments. Furthermore, shade-tolerant trees began infilling earlier in cold–wet than in hot–dry environments and also in topographically shaded sites in the Ochoco Mountains. Our new classification could be used to prioritize management that seeks to restore structure and composition or create resilience in mixed-conifer forests of the region.

Drought responses of conifers in ecotone forests of northern Arizona: tree ring growth and leaf delta13C.

PubMed

Adams, Henry D; Kolb, Thomas E

2004-07-01

We sought to understand differences in tree response to meteorological drought among species and soil types at two ecotone forests in northern Arizona, the pinyon-juniper woodland/ponderosa pine ecotone, and the higher elevation, wetter, ponderosa pine/mixed conifer ecotone. We used two approaches that provide different information about drought response: the ratio of standardized radial growth in wet years to dry years (W:D) for the period between years 1950 and 2000 as a measure of growth response to drought, and delta13C in leaves formed in non-drought (2001) and drought (2002) years as a measure of change in water use efficiency (WUE) in response to drought. W:D and leaf delta13C response to drought for Pinus edulis and P. ponderosa did not differ for trees growing on coarse-texture soils derived from cinders compared with finer textured soils derived from flow basalts or sedimentary rocks. P. ponderosa growing near its low elevation range limit at the pinyon-juniper woodland/ponderosa pine ecotone had a greater growth response to drought (higher W:D) and a larger increase in WUE in response to drought than co-occurring P. edulis growing near its high elevation range limit. P. flexilis and Pseudotsuga menziesii growing near their low elevation range limit at the ponderosa pine/mixed conifer ecotone had a larger growth response to drought than co-occurring P. ponderosa growing near its high elevation range limit. Increases in WUE in response to drought were similar for all species at the ponderosa pine/mixed conifer ecotone. Low elevation populations of P. ponderosa had greater growth response to drought than high-elevation populations, whereas populations had a similar increase in WUE in response to drought. Our findings of different responses to drought among co-occurring tree species and between low- and high-elevation populations are interpreted in the context of drought impacts on montane coniferous forests of the southwestern USA.

Optimizing any-aged management of mixed-species stands: II. effects of decision criteria

Treesearch

Robert G. Haight; Robert A. Monserud

1990-01-01

The effects of maximum present value and maximum volume objectives on the efficiencies of alternative silvicultural systems are determined by solving any-aged management problems for mixed-conifer stands in the Northern Rocky Mountains. Any-aged management problems are formulated with periodic planting and harvesting controls and without constraints on the stand age or...

Conifer regeneration in stand-replacement portions of a large mixed-severity wildfire in the Klamath-Siskiyou Mountains

Treesearch

Daniel C. Donato; Joseph B. Fontaine; John L. Campbell; W. Douglas Robinson; J. Boone Kauffman; Beverly E. Law

2009-01-01

Large-scale wildfires (~104-106 ha) have the potential to eliminate seed sources over broad areas and thus may lead to qualitatively different regeneration dynamics than in small burns; however, regeneration after such events has received little study in temperate forests. Following a 200 000 ha mixed-severity...

Detection probabilities of woodpecker nests in mixed conifer forests in Oregon

Treesearch

Robin E. Russell; Victoria A. Saab; Jay J. Rotella; Jonathan G. Dudley

2009-01-01

Accurate estimates of Black-backed (Picoides arcticus) and Hairy Woodpecker (P. villosus) nests and nest survival rates in post-fire landscapes provide land managers with information on the relative importance of burned forests to nesting woodpeckers. We conducted multiple-observer surveys in burned and unburned mixed coniferous forests in Oregon to identify important...

Influences of the vegetation mosaic on riparian and stream environments in a mixed forest-grassland landscape in "Mediterranean" northwestern California

Treesearch

Hartwell H Welsh Jr; Garth R. Hodgson; Nancy E. Karraker

2005-01-01

We examined differences in riparian and aquatic environments within the three dominant vegetation patch types of the Mattole River watershed, a 789-km2 mixed conifer-deciduous (hardwood) forest and grassland-dominated landscape in northwestern California, USA. Riparian and aquatic environments, and particularly microclimates therein, influence...

Headwater riparian invertebrate communities associated with red alder and conifer wood and leaf litter in southeastern Alaska

USGS Publications Warehouse

LeSage, C.M.; Merritt, R.W.; Wipfli, M.S.

2005-01-01

We examined how management of young upland forests in southeastern Alaska affect riparian invertebrate taxa richness, density, and biomass, in turn, potentially influencing food abundance for fish and wildlife. Southeastern Alaska forests are dominated by coniferous trees including Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), with mixed stands of red cedar (Thuja plicata Donn.). Red alder (Alnus rubra Bong.) is hypothesized to influence the productivity of young-growth conifer forests and through forest management may provide increased riparian invertebrate abundance. To compare and contrast invertebrate densities between coniferous and alder riparian habitats, leaf litter and wood debris (early and late decay classes) samples were collected along eleven headwater streams on Prince of Wales Island, Alaska, during the summers of 2000 and 2001. Members of Acarina and Collembola were the most abundant taxa collected in leaf litter with alder litter having significantly higher mean taxa richness than conifer litter. Members of Acarina were the most abundant group collected on wood debris and alder wood had significantly higher mean taxa richness and biomass than conifer wood. Alder wood debris in more advanced decay stages had the highest mean taxa richness and biomass, compared to other wood types, while conifer late decay wood debris had the highest densities of invertebrates. The inclusion of alder in young-growth conifer forests can benefit forest ecosystems by enhancing taxa richness and biomass of riparian forest invertebrates. ?? 2005 by the Northwest Scientific Association. All rights reserved.

Avian community response to small-scale habitat disturbance in Maine

USGS Publications Warehouse

Derleth, E.L.; McAuley, D.G.; Dwyer, T.J.

1989-01-01

The effects of small clearcuts (1 - 8 ha) on avian communities in the forest of eastern Maine were studied using point counts during spring 1978 - 1981. Surveys were conducted in uncut (control) and clear-cut (treatment) plots in three stand types: conifer, hardwood, and mixed growth. We used a mark-recapture model and its associated jackknife species richness estimator (N), as an indicator of avian community structure. Increases in estimated richness (N) and Shannon - Weaver diversity (H') were noted in the treated hardwood and mixed growth, but not in the conifer stands. Seventeen avian species increased in relative abundance, whereas two species declined. Stand treatment was associated with important changes in bird species composition. Increased habitat patchiness and the creation of forest edge are hypothesized as causes for the greater estimates of richness and diversity.

Areas of Agreement and Disagreement Regarding Ponderosa Pine and Mixed Conifer Forest Fire Regimes: A Dialogue with Stevens et al.

PubMed Central

Odion, Dennis C.; Hanson, Chad T.; Baker, William L.; DellaSala, Dominick A.; Williams, Mark A.

2016-01-01

In a recent PLOS ONE paper, we conducted an evidence-based analysis of current versus historical fire regimes and concluded that traditionally defined reference conditions of low-severity fire regimes for ponderosa pine (Pinus ponderosa) and mixed-conifer forests were incomplete, missing considerable variability in forest structure and fire regimes. Stevens et al. (this issue) agree that high-severity fire was a component of these forests, but disagree that one of the several sources of evidence, stand age from a large number of forest inventory and analysis (FIA) plots across the western USA, support our findings that severe fire played more than a minor role ecologically in these forests. Here we highlight areas of agreement and disagreement about past fire, and analyze the methods Stevens et al. used to assess the FIA stand-age data. We found a major problem with a calculation they used to conclude that the FIA data were not useful for evaluating fire regimes. Their calculation, as well as a narrowing of the definition of high-severity fire from the one we used, leads to a large underestimate of conditions consistent with historical high-severity fire. The FIA stand age data do have limitations but they are consistent with other landscape-inference data sources in supporting a broader paradigm about historical variability of fire in ponderosa and mixed-conifer forests than had been traditionally recognized, as described in our previous PLOS paper. PMID:27195808

Influence of landscape structure, topography, and forest type on spatial variation in historical fire regimes, central Oregon, USA

USGS Publications Warehouse

Merschel, Andrew; Heyerdahl, Emily K.; Spies, Thomas A; Loehman, Rachel A.

2018-01-01

Context In the interior Northwest, debate over restoring mixed-conifer forests after a century of fire exclusion is hampered by poor understanding of the pattern and causes of spatial variation in historical fire regimes. Objectives To identify the roles of topography, landscape structure, and forest type in driving spatial variation in historical fire regimes in mixed-conifer forests of central Oregon. Methods We used tree rings to reconstruct multicentury fire and forest histories at 105 plots over 10,393 ha. We classified fire regimes into four types and assessed whether they varied with topography, the location of fuel-limited pumice basins that inhibit fire spread, and an updated classification of forest type. Results We identified four fire-regime types and six forest types. Although surface fires were frequent and often extensive, severe fires were rare in all four types. Fire regimes varied with some aspects of topography (elevation), but not others (slope or aspect) and with the distribution of pumice basins. Fire regimes did not strictly co-vary with mixed-conifer forest types. Conclusions Our work reveals the persistent influence of landscape structure on spatial variation in historical fire regimes and can help inform discussions about appropriate restoration of fire-excluded forests in the interior Northwest. Where the goal is to restore historical fire regimes at landscape scales, managers may want to consider the influence of topoedaphic and vegetation patch types that could affect fire spread and ignition frequency.

Areas of Agreement and Disagreement Regarding Ponderosa Pine and Mixed Conifer Forest Fire Regimes: A Dialogue with Stevens et al.

PubMed

Odion, Dennis C; Hanson, Chad T; Baker, William L; DellaSala, Dominick A; Williams, Mark A

2016-01-01

In a recent PLOS ONE paper, we conducted an evidence-based analysis of current versus historical fire regimes and concluded that traditionally defined reference conditions of low-severity fire regimes for ponderosa pine (Pinus ponderosa) and mixed-conifer forests were incomplete, missing considerable variability in forest structure and fire regimes. Stevens et al. (this issue) agree that high-severity fire was a component of these forests, but disagree that one of the several sources of evidence, stand age from a large number of forest inventory and analysis (FIA) plots across the western USA, support our findings that severe fire played more than a minor role ecologically in these forests. Here we highlight areas of agreement and disagreement about past fire, and analyze the methods Stevens et al. used to assess the FIA stand-age data. We found a major problem with a calculation they used to conclude that the FIA data were not useful for evaluating fire regimes. Their calculation, as well as a narrowing of the definition of high-severity fire from the one we used, leads to a large underestimate of conditions consistent with historical high-severity fire. The FIA stand age data do have limitations but they are consistent with other landscape-inference data sources in supporting a broader paradigm about historical variability of fire in ponderosa and mixed-conifer forests than had been traditionally recognized, as described in our previous PLOS paper.

Distribution of Mature Cones, Conelets, and Old Cones in Shortleaf Pine-Oak Stands an Uneven-Aged Regeneration Cut

Treesearch

Kenneth J. Grayson; Robert F. Wittwer; Michael G. Shelton

2004-01-01

Sixteen shortleaf pine trees were felled in a stand 10 years after an uneven-aged regeneration cut reduced pine basal area to 60 square feet per acre and hardwoods were controlled. Sixteen unreleased trees in an adjacent uncut pine-hardwood stand (120 square feet per acre) were felled for comparison. Sample trees were selected from four 2-inch d.b.h. classes (11, 13,...

Uneven-aged silviculture and management in the eastern United States: Proceedings of an In-Service Workshop; Morgantown, West Virginia; July 15-17, 1975

Treesearch

Warren T. Doolittle; A. P. Mustain; Carter B. Gibbs; David. A. Marquis; Barton M. Blum; Carl H. Tubbs; W. B. Leak; S. F. Gingrich; H. Clay Smith; Paul S. DeBald; LaMont G. Engle; Robert E. Phares

1975-01-01

The workshop, summarized in this Proceedings, represented a joint effort by personnel from Research, National Forest System, and State and Private Forestry, to review the state-of-the-art knowledge about the applicability of uneven-aged silviculture and management in the eastern United States. One major objective of this review was to develop a much better mutual...

A 10-Year Evaluation of Prescribed Winter Burns in Uneven-Aged Stands of Pinus taeda L. and P. echinata Mill.: Woody Understorey Vegetation Response

Treesearch

Michael D. Cain

1993-01-01

Abstract.The effects of burning cycles and pine basal area levels were assessed on natural pine regeneration and hardwood development in uneven-aged stands of loblolly andshortleafpines (Pinw taeda L. and P. echinata Mill.). The treatments included an unburned control and prescribed winter burrs at 3-, 6-, and 9-yr intervals. Basal area treatments were 9, 14, 18, and...

Forest diversity and disturbance: changing influences and the future of Virginia's Forests

Treesearch

Christine J. Small; James L. Chamberlain

2015-01-01

The Virginia landscape supports a remarkable diversity of forests, from maritime dunes, swamp forests, and pine savannas of the Atlantic coastal plain, to post-agricultural pine-hardwood forests of the piedmont, to mixed oak, mixed-mesophytic, northern hardwood, and high elevation conifer forests in Appalachian mountain provinces. Virginia’s forests also have been...

Influence of age on growth efficiency of Tsuga canadensis and Picea rubens trees in mixed-species, multiaged northern conifer stands

Treesearch

Robert S. Seymour; Laura S. Kenefic

2002-01-01

Well-known patterns in the fundamental relationship between tree-level stemwood volume increment (VINC) and projected leaf area (PLA) are examined and quantified for Tsuga Canadensis (L.) Carriere (eastern hemlock) and Picea rubens Sarg. (red spruce) growing in managed, mixed-species, multiaged stands in east-central Maine, U.S.A....

Influence of soil thickness on stand characteristics in a Sierra Nevada mixed-conifer forest

Treesearch

Marc D. Meyer; Malcolm P. North; Andrew N. Gray; Harold S. J. Zald

2007-01-01

Soil thickness can be an important factor influencing vegetation, yet few spatially explicit studies have examined soil horizon thickness and vegetation composition in summer drought forests. We compared seismic and soil penetration measurements of combined A + C and Cr horizon thickness, soil moisture and temperature, and stand variables in a contiguous 4-ha mixed-...

Uneven-aged silviculture can enhance within stand heterogeneity and beetle diversity.

PubMed

Joelsson, Klara; Hjältén, Joakim; Work, Timothy

2018-01-01

Uneven-aged silviculture may better maintain species assemblages associated with old-growth forests than clear felling in part due to habitat heterogeneity created by maintaining standing retention strips adjacent to harvest trails. Retention strips and harvest trails created at the time of tree removal will likely have different microclimate and may harbor different assemblages. In some cases, the resultant stand heterogeneity associated with uneven-aged silviculture may be similar to natural small-scale disturbances. For beetles, increased light and temperature as well as potential access to young vegetation and deadwood substrates present in harvset trails may harbor beetle assemblages similar to those found in natural gaps. We sampled saproxylic beetles using flight intercept traps placed in harvest corridors and retention strips in 9 replicated uneven-aged spruce stands in central Sweden. We compared abundance, species richness and composition between harvest corridors and retention strips using generalized linear models, rarefaction, permutational multivariate analysis of variance and indicator species analysis. Canopy openness doubled, mean temperature and variability in daily temperature increased and humidity decreased on harvest trails. Beetle richness and abundance were greater in harvests trails than in retention strips and the beetle species composition differed significantly between habitats. Twenty-five species were associated with harvest trails, including three old-growth specialists such as Agathidium discoideum (Erichson), currently red-listed. We observed only one species, Xylechinus pilosus (Ratzeburg) that strongly favored retention strips. Harvest trails foster both open habitat species and old-growth species while retention strips harbored forest interior specialists. The combination of closed canopy, stratified forest in the retention strips and gap-like conditions on the harvest trails thus increases overall species richness and maintains more diverse assemblages at the stand level than would otherwise be seen in less heterogeneous stand types. This suggests that uneven-aged silviculture may provide added conservation benefits for both open habitat and old-growth specialists than silvicultural approaches that reduce stand heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Probability of detecting band-tailed pigeons during call-broadcast versus auditory surveys

USGS Publications Warehouse

Kirkpatrick, C.; Conway, C.J.; Hughes, K.M.; Devos, J.C.

2007-01-01

Estimates of population trend for the interior subspecies of band-tailed pigeon (Patagioenas fasciata fasciata) are not available because no standardized survey method exists for monitoring the interior subspecies. We evaluated 2 potential band-tailed pigeon survey methods (auditory and call-broadcast surveys) from 2002 to 2004 in 5 mountain ranges in southern Arizona, USA, and in mixed-conifer forest throughout the state. Both auditory and call-broadcast surveys produced low numbers of cooing pigeons detected per survey route (x?? ??? 0.67) and had relatively high temporal variance in average number of cooing pigeons detected during replicate surveys (CV ??? 161%). However, compared to auditory surveys, use of call-broadcast increased 1) the percentage of replicate surveys on which ???1 cooing pigeon was detected by an average of 16%, and 2) the number of cooing pigeons detected per survey route by an average of 29%, with this difference being greatest during the first 45 minutes of the morning survey period. Moreover, probability of detecting a cooing pigeon was 27% greater during call-broadcast (0.80) versus auditory (0.63) surveys. We found that cooing pigeons were most common in mixed-conifer forest in southern Arizona and density of male pigeons in mixed-conifer forest throughout the state averaged 0.004 (SE = 0.001) pigeons/ha. Our results are the first to show that call-broadcast increases the probability of detecting band-tailed pigeons (or any species of Columbidae) during surveys. Call-broadcast surveys may provide a useful method for monitoring populations of the interior subspecies of band-tailed pigeon in areas where other survey methods are inappropriate.

A cross-site comparison of factors influencing soil nitrification rates in northeastern USA forested watersheds

USGS Publications Warehouse

Ross, D.S.; Wemple, B.C.; Jamison, A.E.; Fredriksen, G.; Shanley, J.B.; Lawrence, G.B.; Bailey, S.W.; Campbell, J.L.

2009-01-01

Elevated N deposition is continuing on many forested landscapes around the world and our understanding of ecosystem response is incomplete. Soil processes, especially nitrification, are critical. Many studies of soil N transformations have focused on identifying relationships within a single watershed but these results are often not transferable. We studied 10 small forested research watersheds in the northeastern USA to determine if there were common factors related to soil ammonification and nitrification. Vegetation varied between mixed northern hardwoods and mixed conifers. Watershed surface soils (Oa or A horizons) were sampled at grid or transect points and analyzed for a suite of chemical characteristics. At each sampling point, vegetation and topographic metrics (field and GIS-based) were also obtained. Results were examined by watershed averages (n = 10), seasonal/watershed averages (n = 28), and individual sampling points (n = 608). Using both linear and tree regression techniques, the proportion of conifer species was the single best predictor of nitrification rates, with lower rates at higher conifer dominance. Similar to other studies, the soil C/N ratio was also a good predictor and was well correlated with conifer dominance. Unlike other studies, the presence of Acer saccharum was not by itself a strong predictor, but was when combined with the presence of Betula alleghaniensis. Topographic metrics (slope, aspect, relative elevation, and the topographic index) were not related to N transformation rates across the watersheds. Although found to be significant in other studies, neither soil pH, Ca nor Al was related to nitrification. Results showed a strong relationship between dominant vegetation, soil C, and soil C/N. ?? 2008 Springer Science+Business Media, LLC.

Holocene vegetation and fire regimes in subalpine and mixed conifer forests, southern Rocky Mountains, USA

USGS Publications Warehouse

Anderson, R. Scott; Allen, Craig D.; Toney, J.L.; Jass, R.B.; Bair, A.N.

2008-01-01

Our understanding of the present forest structure of western North America hinges on our ability to determine antecedent forest conditions. Sedimentary records from lakes and bogs in the southern Rocky Mountains of Colorado and New Mexico provide information on the relationships between climate and vegetation change, and fire history since deglaciation. We present a new pollen record from Hunters Lake (Colorado) as an example of a high-elevation vegetation history from the southern Rockies. We then present a series of six sedimentary records from ???2600 to 3500-m elevation, including sites presently at the alpine?subalpine boundary, within the Picea engelmannii?Abies lasiocarpa forest and within the mixed conifer forest, to determine the history of fire in high-elevation forests there. High Artemisia and low but increasing percentages of Picea and Pinus suggest vegetation prior to 13 500 calendar years before present (cal yr BP) was tundra or steppe, with open spruce woodland to ???11 900 cal yr BP. Subalpine forest (Picea engelmannii, Abies lasiocarpa) existed around the lake for the remainder of the Holocene. At lower elevations, Pinus ponderosa and/or contorta expanded 11 900 to 10 200 cal yr BP; mixed conifer forest expanded ???8600 to 4700 cal yr BP; and Pinus edulis expanded after ???4700 cal yr BP. Sediments from lake sites near the alpine?subalpine transition contained five times less charcoal than those entirely within subalpine forests, and 40 times less than bog sites within mixed conifer forest. Higher fire episode frequencies occurred between ???12 000 and 9000 cal yr BP (associated with the initiation or expansion of south-west monsoon and abundant lightning, and significant biomass during vegetation turnover) and at ???2000?1000 cal yr BP (related to periodic droughts during the long-term trend towards wetter conditions and greater biomass). Fire episode frequencies for subalpine?alpine transition and subalpine sites were on average 5 to 10 fire events/1000 years over the Holocene, corresponding to one fire event every ???100 to 200 years. (5) Our Holocene-length sedimentary charcoal records provide additional evidence for the anomalous nature of the 20th-century fire regime, where fires were largely suppressed as a national policy. ?? IAWF 2008.

Rapid increase in log populations in drought-stressed mixed-conifer and ponderosa pine forests in northern Arizona

Treesearch

Joseph L. Ganey; Scott C. Vojta

2012-01-01

Down logs provide important ecosystem services in forests and affect surface fuel loads and fire behavior. Amounts and kinds of logs are influenced by factors such as forest type, disturbance regime, forest man-agement, and climate. To quantify potential short-term changes in log populations during a recent global- climate-change type drought, we sampled logs in mixed-...

Dry forests and wildland fires of the inland Northwest USA: contrasting the landscape ecology of the pre-settlement and modern eras.

Treesearch

Paul F. Hessburg; James K. Agee; Jerry F. Franklin

2005-01-01

Prior to Euro-American settlement, dry ponderosa pine and mixed conifer forests (hereafter, the "dry forests") of the Inland Northwest were burned by frequent low- or mixed-severity fires. These mostly surface fires maintained low and variable tree densities, light and patchy ground fuels, simplified forest structure, and favored fire-tolerant trees, such as...

Emergy and Eco-exergy Evaluation of Four Forest Restoration Modes

EPA Science Inventory

Four different forest restoration modes (Acacia mangium plantation, mixed-native species plantation, conifer plantation and Eucalyptus plantation) were evaluated using Energy System Theory and the emergy synthesis method. In addition, the eco-exergies of the four forest restorati...

Air pollution effects on giant sequoia ecosystems.

Treesearch

P.R. Miller; Nancy Grulke; K.W. Stolte

1994-01-01

Giant sequoia [Sequoiadendron giganteum (Lindl.) Buchholz] groves are found entirely within the Sierra Nevada mixed-conifer type. Several of its companion tree species, mainly ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (P. jeffreyi Grev. & Balf.), show foliar injury after...

Disturbance and productivity interactions mediate stability of forest composition and structure.

PubMed

O'Connor, Christopher D; Falk, Donald A; Lynch, Ann M; Swetnam, Thomas W; Wilcox, Craig P

2017-04-01

Fire is returning to many conifer-dominated forests where species composition and structure have been altered by fire exclusion. Ecological effects of these fires are influenced strongly by the degree of forest change during the fire-free period. Response of fire-adapted species assemblages to extended fire-free intervals is highly variable, even in communities with similar historical fire regimes. This variability in plant community response to fire exclusion is not well understood; however, ecological mechanisms such as individual species' adaptations to disturbance or competition and underlying site characteristics that facilitate or impede establishment and growth have been proposed as potential drivers of assemblage response. We used spatially explicit dendrochronological reconstruction of tree population dynamics and fire regimes to examine the influence of historical disturbance frequency (a proxy for adaptation to disturbance or competition), and potential site productivity (a proxy for underlying site characteristics) on the stability of forest composition and structure along a continuous ecological gradient of pine, dry mixed-conifer, mesic mixed-conifer, and spruce-fir forests following fire exclusion. While average structural density increased in all forests, species composition was relatively stable in the lowest productivity pine-dominated and highest productivity spruce-fir-dominated sites immediately following fire exclusion and for the next 100 years, suggesting site productivity as a primary control on species composition and structure in forests with very different historical fire regimes. Species composition was least stable on intermediate productivity sites dominated by mixed-conifer forests, shifting from primarily fire-adapted species to competition-adapted, fire-sensitive species within 20 years of fire exclusion. Rapid changes to species composition and stand densities have been interpreted by some as evidence of high-severity fire. We demonstrate that the very different ecological process of fire exclusion can produce similar changes by shifting selective pressures from disturbance-mediated to productivity-mediated controls. Restoring disturbance-adapted species composition and structure to intermediate productivity forests may help to buffer them against projected increasing temperatures, lengthening fire seasons, and more frequent and prolonged moisture stress. Fewer management options are available to promote adaptation in forest assemblages historically constrained by underlying site productivity. © 2016 by the Ecological Society of America.

Water transport dynamics in trees and stands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pallardy, S.G.; Cermak, J.; Ewers, F.W.

1995-07-01

Water transport dynamics in trees and stands of conifers have certain features that are characteristic of this group and are at least rare among angiosperms. Among these features is the xylem transport system that is dependent on tracheids for long-distance water transport. Tracheid-containing xylem is relatively inefficient, a property that can reduce submaximum allowable rates of gas exchange, but tracheids also offer substantial capacity for water storage and high resistance to freezing-induced dysfunction. Thus, they are quite compatible with the typical evergreen habit and long transpiration season of conifers. At the stand level, canopy transpiration in conifers is primarily controlledmore » by stomatal conductance. In contrast, in dense canopies of angio-sperms, particularly those of tropical forests with limited air mixing, stand transpiration is limited by radiation input rather than by stomatal control. Because of their evergreen habit a greater proportion of evapotranspiration in conifer forests is associated with evaporation of water intercepted by the tree crowns. Other features of transport dynamics are characteristic of most conifers, but are not unique to this group. Among these features are typically shallow root systems that often must supply water in winter to replace transpiration needs of evergreen species, common occurrence of mycorrhizae that enhance mineral and water uptake, and drought tolerance adaptations that include elements of both dehydration avoidance (e.g., stomatal closure under water stress, shifts in allocation of dry matter to below-ground sinks) and dehydration tolerance (e.g., capacity for acclimation of photosynthetic apparatus to drought, osmotic adjustment). Transpiration rates from conifer foliage often are lower than those of deciduous angiosperms, probably because of the lower maximum capacity of tracheid-bearing xylem to transport water.« less

Xylem traits, leaf longevity and growth phenology predict growth and mortality response to defoliation in northern temperate forests.

PubMed

Foster, Jane R

2017-09-01

Defoliation outbreaks are biological disturbances that alter tree growth and mortality in temperate forests. Trees respond to defoliation in many ways; some recover rapidly, while others decline gradually or die. Functional traits such as xylem anatomy, growth phenology or non-structural carbohydrate (NSC) storage could explain these responses, but idiosyncratic measures used by defoliation studies have frustrated efforts to generalize among species. Here, I test for functional differences with published growth and mortality data from 37 studies, including 24 tree species and 11 defoliators from North America and Eurasia. I synthesized data into standardized variables suitable for numerical models and used linear mixed-effects models to test the hypotheses that responses to defoliation vary among species and functional groups. Standardized data show that defoliation responses vary in shape and degree. Growth decreased linearly or curvilinearly, least in ring-porous Quercus and deciduous conifers (by 10-40% per 100% defoliation), whereas growth of diffuse-porous hardwoods and evergreen conifers declined by 40-100%. Mortality increased exponentially with defoliation, most rapidly for evergreen conifers, then diffuse-porous, then ring-porous species and deciduous conifers (Larix). Goodness-of-fit for functional-group models was strong (R2c = 0.61-0.88), if lower than species-specific mixed-models (R2c = 0.77-0.93), providing useful alternatives when species data are lacking. These responses are consistent with functional differences in leaf longevity, wood growth phenology and NSC storage. When defoliator activity lags behind wood-growth, either because xylem-growth precedes budburst (Quercus) or defoliator activity peaks later (sawflies on Larix), impacts on annual wood-growth will always be lower. Wood-growth phenology of diffuse-porous species and evergreen conifers coincides with defoliation and responds more drastically, and lower axial NSC storage makes them more vulnerable to mortality as stress accumulates. These functional differences in response apply in general to disturbances that cause spring defoliation and provide a framework that should be incorporated into forest growth and vegetation models. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Forest gradient response in Sierran landscapes: the physical template

USGS Publications Warehouse

Urban, Dean L.; Miller, Carol; Halpin, Patrick N.; Stephenson, Nathan L.

2000-01-01

Vegetation pattern on landscapes is the manifestation of physical gradients, biotic response to these gradients, and disturbances. Here we focus on the physical template as it governs the distribution of mixed-conifer forests in California's Sierra Nevada. We extended a forest simulation model to examine montane environmental gradients, emphasizing factors affecting the water balance in these summer-dry landscapes. The model simulates the soil moisture regime in terms of the interaction of water supply and demand: supply depends on precipitation and water storage, while evapotranspirational demand varies with solar radiation and temperature. The forest cover itself can affect the water balance via canopy interception and evapotranspiration. We simulated Sierran forests as slope facets, defined as gridded stands of homogeneous topographic exposure, and verified simulated gradient response against sample quadrats distributed across Sequoia National Park. We then performed a modified sensitivity analysis of abiotic factors governing the physical gradient. Importantly, the model's sensitivity to temperature, precipitation, and soil depth varies considerably over the physical template, particularly relative to elevation. The physical drivers of the water balance have characteristic spatial scales that differ by orders of magnitude. Across large spatial extents, temperature and precipitation as defined by elevation primarily govern the location of the mixed conifer zone. If the analysis is constrained to elevations within the mixed-conifer zone, local topography comes into play as it influences drainage. Soil depth varies considerably at all measured scales, and is especially dominant at fine (within-stand) scales. Physical site variables can influence soil moisture deficit either by affecting water supply or water demand; these effects have qualitatively different implications for forest response. These results have clear implications about purely inferential approaches to gradient analysis, and bear strongly on our ability to use correlative approaches in assessing the potential responses of montane forests to anthropogenic climatic change.

Bat Response to Differing Fire Severity in Mixed-Conifer Forest California, USA

PubMed Central

Heady, Paul A.; Hayes, John P.; Frick, Winifred F.

2013-01-01

Wildlife response to natural disturbances such as fire is of conservation concern to managers, policy makers, and scientists, yet information is scant beyond a few well-studied groups (e.g., birds, small mammals). We examined the effects of wildfire severity on bats, a taxon of high conservation concern, at both the stand (<1 ha) and landscape scale in response to the 2002 McNally fire in the Sierra Nevada region of California, USA. One year after fire, we conducted surveys of echolocation activity at 14 survey locations, stratified in riparian and upland habitat, in mixed-conifer forest habitats spanning three levels of burn severity: unburned, moderate, and high. Bat activity in burned areas was either equivalent or higher than in unburned stands for all six phonic groups measured, with four groups having significantly greater activity in at least one burn severity level. Evidence of differentiation between fire severities was observed with some Myotis species having higher levels of activity in stands of high-severity burn. Larger-bodied bats, typically adapted to more open habitat, showed no response to fire. We found differential use of riparian and upland habitats among the phonic groups, yet no interaction of habitat type by fire severity was found. Extent of high-severity fire damage in the landscape had no effect on activity of bats in unburned sites suggesting no landscape effect of fire on foraging site selection and emphasizing stand-scale conditions driving bat activity. Results from this fire in mixed-conifer forests of California suggest that bats are resilient to landscape-scale fire and that some species are preferentially selecting burned areas for foraging, perhaps facilitated by reduced clutter and increased post-fire availability of prey and roosts. PMID:23483936

A taxonomic monograph of Nearctic Scolytus Geoffroy (Coleoptera, Curculionidae, Scolytinae).

PubMed

Smith, Sarah M; Cognato, Anthony I

2014-01-01

The Nearctic bark beetle genus Scolytus Geoffroy was revised based in part on a molecular and morphological phylogeny. Monophyly of the native species was tested using mitochondrial (COI) and nuclear (28S, CAD, ArgK) genes and 43 morphological characters in parsimony and Bayesian phylogenetic analyses. Parsimony analyses of molecular and combined datasets provided mixed results while Bayesian analysis recovered most nodes with posterior probabilities >90%. Native hardwood- and conifer-feeding Scolytus species were recovered as paraphyletic. Native Nearctic species were recovered as paraphyletic with hardwood-feeding species sister to Palearctic hardwood-feeding species rather than to native conifer-feeding species. The Nearctic conifer-feeding species were monophyletic. Twenty-five species were recognized. Four new synonyms were discovered: Scolytuspraeceps LeConte, 1868 (= Scolytusabietis Blackman, 1934; = Scolytusopacus Blackman, 1934), Scolytusreflexus Blackman, 1934 (= Scolytusvirgatus Bright, 1972; = Scolytuswickhami Blackman, 1934). Two species were reinstated: Scolytusfiskei Blackman, 1934 and Scolytussilvaticus Bright, 1972. A diagnosis, description, distribution, host records and images were provided for each species and a key is presented to all species.

DRY DEPOSITION OF POLLUTANTS TO FORESTS

EPA Science Inventory

We report on the results of an extensive field campaign to measure dry deposition of ozone and sulfur dioxide to a sample of forest types in the United States. Measurements were made for full growing seasons over a deciduous forest in Pennsylvania and a mixed deciduous-conifer...

Negligible influence of spatial autocorrelation in the assessment of fire effects in a mixed conifer forest

USGS Publications Warehouse

van Mantgem, P.J.; Schwilk, D.W.

2009-01-01

Fire is an important feature of many forest ecosystems, although the quantification of its effects is compromised by the large scale at which fire occurs and its inherent unpredictability. A recurring problem is the use of subsamples collected within individual burns, potentially resulting in spatially autocorrelated data. Using subsamples from six different fires (and three unburned control areas) we show little evidence for strong spatial autocorrelation either before or after burning for eight measures of forest conditions (both fuels and vegetation). Additionally, including a term for spatially autocorrelated errors provided little improvement for simple linear models contrasting the effects of early versus late season burning. While the effects of spatial autocorrelation should always be examined, it may not always greatly influence assessments of fire effects. If high patch scale variability is common in Sierra Nevada mixed conifer forests, even following more than a century of fire exclusion, treatments designed to encourage further heterogeneity in forest conditions prior to the reintroduction of fire will likely be unnecessary.

Implications for Late Pleistocene Mastodon Diet from Opal Phytoliths in Tooth Calculus

NASA Astrophysics Data System (ADS)

Gobetz, Katrina E.; Bozarth, Steven R.

2001-03-01

Calculus removed from the molar teeth of four American mastodons (Mammut americanum) contained opal phytoliths which reflect major dietary components. Three samples contained abundant grass phytoliths (ca. 86% of total), with long cells and trapezoidal pooid short cells dominant (ca. 25 and 31%, respectively). Dicot phytoliths from hackberry (Celtis sp.) seeds and indeterminate deciduous trees were rare (1-3%), though well preserved, whereas phytoliths from conifer trees were not recognizable in any of the samples. Comparative analysis of calculus from modern and fossil browsers and mixed feeders implies that dicots and conifers are nearly invisible in the phytolith record. This scarcity may result from poor preservation, low silica production in woody taxa, and/or animals' selection of young, silica-poor leaves and shoots. However, abundant grass phytoliths in the mixed feeders suggest that presence versus absence of grass phytoliths may distinguish mixed feeders and grazers from browsers. Mastodons are traditionally considered browsers, but grass phytolith assemblages in three individual mastodons contained similarly high concentrations of pooids, suggesting that these grasses were a significant part of the diet. Abundant pooid phytoliths, in addition to diatoms, indicate that these mastodons grazed in a cool, moist late Pleistocene environment, possibly near water.

Reproductive biology of the Del Norte salamander (Plethodon elongatus).

Treesearch

Clara A. Wheeler; Hartwell H. Welsh Jr.; Lisa M. Ollivier

2013-01-01

We examined seasonal reproductive patterns of the Del Norte Salamander, Plethodon elongatus, in mixed conifer and hardwood forests of northwestern California and southwestern Oregon. Seasonal size differences in reproductive structures suggested that maximum spermatogenic activity occurred during the late summer, with spermatozoa transfer to the...

Effect of fuels reduction on American martens and their prey.

Treesearch

Evelyn L. Bull; Arlene K. Blumton

1999-01-01

The effect of a fuels reduction treatment on small mammals was investigated in lodgepole pine (Pinus contorta) and mixed conifer stands by trapping and track surveys in northeastern Oregon. The number of red squirrel (Tamiasciurus hudsonicus) and snowshoe hare (Lepus americanus) tracks decreased in all...

Influence of vegetation structure on lidar-derived canopy height and fractional cover in forested riparian buffers during leaf-off and leaf-on conditions.

PubMed

Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

2013-01-01

Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available.

Contrasting spatial patterns in active-fire and fire-suppressed Mediterranean climate old-growth mixed conifer forests.

PubMed

Fry, Danny L; Stephens, Scott L; Collins, Brandon M; North, Malcolm P; Franco-Vizcaíno, Ernesto; Gill, Samantha J

2014-01-01

In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbance regimes and climate. In this study, we characterize tree spatial patterns using four-ha stem maps from four old-growth, Jeffrey pine-mixed conifer forests, two with active-fire regimes in northwestern Mexico and two that experienced fire exclusion in the southern Sierra Nevada. Most of the trees were in patches, averaging six to 11 trees per patch at 0.007 to 0.014 ha(-1), and occupied 27-46% of the study areas. Average canopy gap sizes (0.04 ha) covering 11-20% of the area were not significantly different among sites. The putative main effects of fire exclusion were higher densities of single trees in smaller size classes, larger proportion of trees (≥ 56%) in large patches (≥ 10 trees), and decreases in spatial complexity. While a homogenization of forest structure has been a typical result from fire exclusion, some similarities in patch, single tree, and gap attributes were maintained at these sites. These within-stand descriptions provide spatially relevant benchmarks from which to manage for structural heterogeneity in frequent-fire forest types.

Influence of Vegetation Structure on Lidar-derived Canopy Height and Fractional Cover in Forested Riparian Buffers During Leaf-Off and Leaf-On Conditions

PubMed Central

Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

2013-01-01

Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available. PMID:23382966

A pilot experiment of forest fertilization during an outbreak of the western spruce budworm in northeastern Oregon.

Treesearch

R.R. Mason; B.E. Wickman; H.G. Paul; T.R. Torgersen

1998-01-01

Mixed-conifer stands of grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), and ponderosa pine (Pinus ponderosa Dougl. ex Laws.) were fertilized with nitrogen and combination treatments of nitrogen, phosphorus, potassium...

Prescribed burning and mechanical thinning effects on belowground conditions and soil respiration in a mixed-conifer forest, California

Treesearch

Soung-Ryoul Ryu; Amy Concilio; Jiquan Chen; Malcolm North; Siyan Ma

2009-01-01

Soil respiration (RS) is a major carbon pathway from terrestrial ecosystems to the atmosphere and is sensitive to environmental changes. Although commonly used mechanical thinning and prescribed burning can significantly alter the soil environment, the effect of these practices on RS...

Chapter 10: Geographic information system landscape analysis using GTR 220 concepts

Treesearch

M. North; R.M. Boynton; P.A. Stine; K.F. Shipley; E.C. Underwood; N.E. Roth; J.H. Viers; J.F. Quinn

2012-01-01

Forest Service General Technical Report "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests" (hereafter GTR 220) (North et al. 2009) emphasizes increasing forest heterogeneity throughout a range of spatial scales including within-stand microsites, individual stands, watersheds, and entire landscapes. For fuels reduction, various landscape...

Chapter 7: Developing collaboration and cooperation

Treesearch

G. Bartlett

2012-01-01

Good forestry practices require onsite flexibility. A core concept in U.S. Forest Service General Technical Report PSW-GTR-220 "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests" (North et al. 2009) is that management treatments and thinning intensity should differ depending on local forest conditions and topographic location. In the...

Atmospheric chemistry

Treesearch

Andrzej Bytnerowicz; Mark Fenn; Edith B. Allen; Ricardo Cisneros

2016-01-01

At present, negative impacts of air pollution on California ecosystems are caused mainly by elevated levels of ozone and nitrogen deposition. Generally, ozone air pollution in California has been improving significantly since the 1970s; however, it still causes serious ecological and human health effects. The most serious ecological effects occur in mixed conifer...

Some lessons in artificial regeneration from southwestern Oregon.

Treesearch

William I. Stein

1955-01-01

Natural reproduction has often proved undependable for restocking cutovers and burns in the mixed-conifer forest types of southwestern Oregon. These types, covering 6,000 square miles of productive forest land in the five southwestern Oregon counties, are composed of many species--principally Douglas fir, Pseudotsuga menziesii (Mirb.) Franco;...

78 FR 39763 - Recovery Plan Addendum; Thick-Billed Parrot

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... addendum to comply with a December 14, 2010, Stipulated Settlement Agreement between WildEarth Guardians... plan addendum to comply with the December 14, 2010, Stipulated Settlement Agreement between WildEarth...-billed parrots live in gregarious flocks in old-growth mixed- conifer forests and require a diversity of...

Eco-exergy and emergy based self-organization of three forest plantations in lower subtropical China

EPA Science Inventory

The bio-thermodynamic structures of a mixed native species plantation, a conifer plantation and an Acacia mangium plantation in Southern China were quantified over a period of 15 years based on eco-exergy methods. The efficiencies of structural development and maintenance were qu...

Highly stocked coniferous stands on the Olympic Peninsula: chemical composition and implications for harvest strategy.

Treesearch

Susan N. Little; Dale R. Waddell

1987-01-01

This report presents an assessment of macronutrients and their distribution within highly stocked, stagnant stands of mixed conifers on the Quilcene Ranger District, Olympic National Forest, northwest Washington. These stands consisted of predominantly three species: western hemlock (Tsuga heterophylla (Raf.) Sarg.), coast Douglas-fir (...

Home range characteristics of fishers in California

Treesearch

W. J. Zielinski; R. L. Truex; G. A. Schmidt; F. V. Schlexer; K. N. Schmidt; R. H. Barrett

2004-01-01

The fisher (Martes pennanti) is a forest mustelid that historically occurred in California from the mixed conifer forests of the north coast, east to the southern Cascades, and south throughout the Sierra Nevada. Today fishers in California occur only in 2 disjunct populations in the northwestern mountains and the...

Alternative approaches to mixed conifer forest restoration: partitioning the competitive neighborhood

Treesearch

Michael I. Premer; Sophan Chhin; Jianwei Zhang

2017-01-01

Forest restoration efforts in the intermountain west of North America generally seek to promote the continuation of pine dominance, enhance wildlife habitat, and decrease hazardous fuels, thereby mitigating catastrophic losses from various stressors and disturbances. We propose a method of focal tree release thinning that partitions the...

An ecosystem management strategy for Sierran mixed-conifer forests

Treesearch

Malcolm North; Peter Stine; Kevin O' Hara; William Zielinski; Scott Stephens

2009-01-01

Current Sierra Nevada forest management is often focused on strategically reducing fuels without an explicit strategy for ecological restoration across the landscape matrix. Summarizing recent scientific literature, we suggest managers produce different stand structures and densities across the landscape using topographic variables (i.e., slope shape, aspect, and slope...

Trends and causes of severity, size, and number of fires in northwestern California, USA.

PubMed

Miller, J D; Skinner, C N; Safford, H D; Knapp, E E; Ramirez, C M

2012-01-01

Research in the last several years has indicated that fire size and frequency are on the rise in western U.S. forests. Although fire size and frequency are important, they do not necessarily scale with ecosystem effects of fire, as different ecosystems have different ecological and evolutionary relationships with fire. Our study assessed trends and patterns in fire size and frequency from 1910 to 2008 (all fires > 40 ha), and the percentage of high-severity in fires from 1987 to 2008 (all fires > 400 ha) on the four national forests of northwestern California. During 1910-2008, mean and maximum fire size and total annual area burned increased, but we found no temporal trend in the percentage of high-severity fire during 1987-2008. The time series of severity data was strongly influenced by four years with region-wide lightning events that burned huge areas at primarily low-moderate severity. Regional fire rotation reached a high of 974 years in 1984 and fell to 95 years by 2008. The percentage of high-severity fire in conifer-dominated forests was generally higher in areas dominated by smaller-diameter trees than in areas with larger-diameter trees. For Douglas-fir forests, the percentage of high-severity fire did not differ significantly between areas that re-burned and areas that only burned once (10% vs. 9%) when re-burned within 30 years. Percentage of high-severity fire decreased to 5% when intervals between first and second fires were > 30 years. In contrast, in both mixed-conifer and fir/high-elevation conifer forests, the percentage of high-severity fire was less when re-burned within 30 years compared to first-time burned (12% vs. 16% for mixed conifer; 11% vs. 19% for fir/high-elevation conifer). Additionally, the percentage of high-severity fire did not differ whether the re-burn interval was less than or greater than 30 years. Years with larger fires and greatest area burned were produced by region-wide lightning events, and characterized by less winter and spring precipitation than years dominated by smaller human-ignited fires. Overall percentage of high-severity fire was generally less in years characterized by these region-wide lightning events. Our results suggest that, under certain conditions, wildfires could be more extensively used to achieve ecological and management objectives in northwestern California.

A taxonomic monograph of Nearctic Scolytus Geoffroy (Coleoptera, Curculionidae, Scolytinae)

PubMed Central

Smith, Sarah M.; Cognato, Anthony I.

2014-01-01

Abstract The Nearctic bark beetle genus Scolytus Geoffroy was revised based in part on a molecular and morphological phylogeny. Monophyly of the native species was tested using mitochondrial (COI) and nuclear (28S, CAD, ArgK) genes and 43 morphological characters in parsimony and Bayesian phylogenetic analyses. Parsimony analyses of molecular and combined datasets provided mixed results while Bayesian analysis recovered most nodes with posterior probabilities >90%. Native hardwood- and conifer-feeding Scolytus species were recovered as paraphyletic. Native Nearctic species were recovered as paraphyletic with hardwood-feeding species sister to Palearctic hardwood-feeding species rather than to native conifer-feeding species. The Nearctic conifer-feeding species were monophyletic. Twenty-five species were recognized. Four new synonyms were discovered: Scolytus praeceps LeConte, 1868 (= Scolytus abietis Blackman, 1934; = Scolytus opacus Blackman, 1934), Scolytus reflexus Blackman, 1934 (= Scolytus virgatus Bright, 1972; = Scolytus wickhami Blackman, 1934). Two species were reinstated: Scolytus fiskei Blackman, 1934 and Scolytus silvaticus Bright, 1972. A diagnosis, description, distribution, host records and images were provided for each species and a key is presented to all species. PMID:25408617

Multiscale habitat selection by Ruffed Grouse at low population densities

USGS Publications Warehouse

Zimmerman, G.S.; Gutierrez, R.J.; Thogmartin, W.E.; Banerjee, S.

2009-01-01

Theory suggests habitats should be chosen according to their relative evolutionary benefits and costs. It has been hypothesized that aspen (Populus spp.) forests provide optimal habitat for Ruffed Grouse (Bonasa umbellus). We used the low phase of a grouse population's cycle to assess the prediction that grouse should occupy aspen and avoid other forest types at low population density because of the presumptive fitness benefits of aspen. On the basis of our observations, we predict how the Ruffed Grouse population will increase in different forest types during the next cycle. In conifer (Pinus spp., Abies balsamea, Picea spp.)-dominated and mixed aspen-conifer landscapes, grouse densities were highest where forest types were evenly distributed. Within these landscapes, male Ruffed Grouse selected young aspen stands that were large and round or square. Although Ruffed Grouse selected young aspen stands strongly, contrary to prediction, they also used other forest types even when young aspen stands remained unoccupied. The relative densities of Ruffed Grouse in aspen and conifer forests indicated that the aspen forest's carrying capacities for grouse was higher than the conifer forest's at least during the low and declining phases of the grouse's cycle. On the basis of our observations, we predict that Ruffed Grouse populations in aspen-dominated landscapes will have higher population densities and fluctuate more than will populations in conifer-dominated landscapes. We suggest that studies of avian habitat selection would benefit from knowledge about the relative densities among habitats at differing population sizes because this information could provide insight into the role of habitat in regulating populations and clarify inferences from studies about habitat quality for birds. ?? 2009 by The Cooper Ornithological Society. All rights reserved.

Ponderosa pine, mixed conifer, and spruce-fir forests [Chapter 2

Treesearch

Michael A. Battaglia; Wayne D. Shepperd

2007-01-01

Before European settlement of the interior west of the United States, coniferous forests of this region were influenced by many disturbance regimes, primarily fires, insects, diseases, and herbivory, which maintained a diversity of successional stages and vegetative types across landscapes. Activities after settlement, such as fire suppression, grazing, and logging...

Mixed-conifer understory response to climate change, nitrogen, and fire

Treesearch

Matthew Hurteau; Malcom North

2008-01-01

California’s Sierra Nevada mountains are predicted to experience greater variation in annual precipitation according to climate change models, while nitrogen deposition from pollution continues to increase. These changes may significantly affect understory communities and fuels in forests where managers are attempting to restore historic conditions after a century of...

Relationship between self-fertility, allocation of growth, and inbreeding depression in three coniferous species.

Treesearch

Frank C. Sorensen

1999-01-01

Mortality and growth of self and outcross families of three wind-pollinated, mixed-mating, long-lived conifers, Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), and noble fir (Abies procera) were followed from outplanting to age 26 (25 for noble fir) in spaced plantings at a common...

Fire ecology and management of the major ecosystems of southern Utah

Treesearch

Sharon M. Hood; Melanie Miller

2007-01-01

This document provides managers with a literature synthesis of the historical conditions, current conditions, fire regime condition classes (FRCC), and recommended treatments for the major ecosystems in southern Utah. Sections are by ecosystems and include: 1) coniferous forests (ponderosa pine, mixed conifer, and Engelmann spruce-subalpine fir), 2) aspen, 3) pinyon-...

Growth of thinned and unthinned hardwood stands on a good site in northern California

Treesearch

Philip M. McDonald; Nicholas R. Vaughn

2007-01-01

Pacific madrone (Arbutus menziesii Pursh), tanoak (Lithocarpus densiflorus (Hook. & Arn.) Rehd.), and California black oak (Quercus kelloggii Newb.) are three hardwood species commonly found in the Sierra Nevada of California, an area better known for its mixed-conifer forests. Hardwood stands in this region currently are...

Managing Sierra Nevada forests

Treesearch

Malcolm North

2012-01-01

There has been widespread interest in applying new forest practices based on concepts presented in U.S. Forest Service General Technical Report PSW-GTR-220, "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests." This collection of papers (PSW-GTR-237) summarizes the state of the science in some topics relevant to this forest management approach...

Fire regimes approaching historic norms reduce wildfire-facilitated conversion from forest to non-forest

Treesearch

Ryan B. Walker; Jonathan D. Coop; Sean A. Parks; Laura Trader

2018-01-01

Extensive high-severity wildfires have driven major losses of ponderosa pine and mixed-conifer forests in the southwestern United States, in some settings catalyzing enduring conversions to nonforested vegetation types. Management interventions to reduce the probability of stand-replacing wildfire have included mechanical fuel treatments, prescribed fire, and wildfire...

Modification of mixed-conifer forests by ruminant herbivores in the Blue Mountains ecological province.

Treesearch

Robert A. Riggs; Arthur R. Tiedemann; John G. Cook; et al.

2000-01-01

Secondary plant succession and the accumulation of biomass and nutrients were documented at seven ruminant exclosures in Abies and Pseudotsuga forests variously disturbed by logging, burning, and grass seeding. Long-term (25 or more years) foraging by Rocky Mountain mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus...

Fungi in the diets of northern flying squirrels and lodgepole chipmunks in the Sierra Nevada

Treesearch

Marc D. Meyer; Malcolm P. North; Douglas A. Kelt

2005-01-01

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...

Conifer root proliferation after 20 years of soil compaction

Treesearch

Matt D. Busse; Gary O. Fiddler; Carol J. Shestak

2017-01-01

Soil compaction is known to limit plant growth by reducing soil macroporosity and restricting gas, water, and root movement. Recent evidence from study sites across the United States and Canada, however, suggests that tree growth is not universally affected by soil compaction from forest harvesting practices. Our observational study examined rooting patterns in mixed...

Novel characterization of landscape-level variability in historical vegetation structure

Treesearch

Brandon M. Collins; Jamie M. Lydersen; Richard G. Everett; Danny L. Fry; Scott L. Stephens

2015-01-01

We analyzed historical timber inventory data collected systematically across a large mixed-conifer-dominated landscape to gain insight into the interaction between disturbances and vegetation structure and composition prior to 20th century land management practices. Using records from over 20 000 trees, we quantified historical vegetation structure and composition for...

Soil moisture depletion patterns around scattered trees

Treesearch

Robert R. Ziemer

1968-01-01

Soil moisture was measured around an isolated mature sugar pine tree (Pinus lambertiana Dougl.) in the mixed conifer forest type of the north central Sierra Nevada, California, from November 1965 to October 1966. From a sequence of measurements, horizontal and vertical soil moisture profiles were developed. Estimated soil moisture depletion from the 61-foot radius plot...

Influence of prescribed fire on carabid beetle (Carabidae) and spider (Araneae) assemblages in forest litter in southwestern Oregon.

Treesearch

Christine G. Niwa; Robert W. Peck

2002-01-01

The objective of this study was to determine if prescribed fire affects spider (Araneae) and carabid beetle (Carabidae) abundance, and whether the magnitude of this effect varies with time since fire. Within mixed conifer stands; nine understory fuels-reduction burns, ranging from

76 FR 37141 - Notice of Availability for Comment: Draft Recovery Plan, First Revision; Mexican Spotted Owl

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-24

... the following methods: U.S. mail: Field Supervisor, at the above address; Hand-delivery: Arizona... important to Mexican spotted owls are mixed conifer, pine-oak, and riparian habitats. Threats to the owl's... significant revision since the original plan, incorporating the most recent scientific research specific to...

Nest trees of northern flying squirrels in the Sierra Nevada

Treesearch

Marc D. Meyer; Douglas A. Kelt; Malcolm P. North

2005-01-01

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...

Growing reforestation conifer stock: Utilizing peat/sawdust medium

Treesearch

Janice K. Schaefer

2009-01-01

Western Forest Systems, Incorporated (WFS) (Lewiston, ID) has been utilizing a peat/sawdust blended mix as our growing medium for the past 10 years. Our decision to change from a peat/vermiculite blend to a peat/Douglas-fir (Pseudotsuga menziesii) sawdust blend involved worker health and safety issues, seedling culture, seedling production, and...

Bird communities and environmental correlates in southern Oregon and northern California, USA

Treesearch

Jaime L. Stephens; Eric C. Dinger; John D. Alexander; Sean R. Mohren; C. John Ralph; Daniel A. Sarr

2016-01-01

We examined avian community ecology in the Klamath Ecoregion and determined that individual bird species co-exist spatially to form 29 statistically distinguishable bird groups. We identified climate, geography, and vegetation metrics that are correlated with these 29 bird groups at three scales: Klamath Ecoregion, vegetation formation (agriculture, conifer, mixed...

Soil respiration response to experimental disturbances over 3 years

Treesearch

Amy Concilio; Siyan Ma; Soung-Ryoul Ryu; Malcolm North; Jiquan Chen

2006-01-01

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, mixed-conifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments...

Visualization of heterogeneous forest structures following treatment in the southern Rocky Mountains

Treesearch

Wade T. Tinkham; Yvette Dickinson; Chad M. Hoffman; Mike A. Battaglia; Seth Ex; Jeffrey Underhill

2017-01-01

Manipulation of forest spatial patterns has become a common objective in restoration prescriptions throughout the central and southern Rocky Mountain dry-mixed conifer forest systems. Pre-Euro-American settlement forest reconstructions indicate that frequent-fire regimes developed forests with complex mosaics of individual trees, tree clumps of varying size, and...

Simple method for direct crown base height estimation of individual conifer trees using airborne LiDAR data.

PubMed

Luo, Laiping; Zhai, Qiuping; Su, Yanjun; Ma, Qin; Kelly, Maggi; Guo, Qinghua

2018-05-14

Crown base height (CBH) is an essential tree biophysical parameter for many applications in forest management, forest fuel treatment, wildfire modeling, ecosystem modeling and global climate change studies. Accurate and automatic estimation of CBH for individual trees is still a challenging task. Airborne light detection and ranging (LiDAR) provides reliable and promising data for estimating CBH. Various methods have been developed to calculate CBH indirectly using regression-based means from airborne LiDAR data and field measurements. However, little attention has been paid to directly calculate CBH at the individual tree scale in mixed-species forests without field measurements. In this study, we propose a new method for directly estimating individual-tree CBH from airborne LiDAR data. Our method involves two main strategies: 1) removing noise and understory vegetation for each tree; and 2) estimating CBH by generating percentile ranking profile for each tree and using a spline curve to identify its inflection points. These two strategies lend our method the advantages of no requirement of field measurements and being efficient and effective in mixed-species forests. The proposed method was applied to a mixed conifer forest in the Sierra Nevada, California and was validated by field measurements. The results showed that our method can directly estimate CBH at individual tree level with a root-mean-squared error of 1.62 m, a coefficient of determination of 0.88 and a relative bias of 3.36%. Furthermore, we systematically analyzed the accuracies among different height groups and tree species by comparing with field measurements. Our results implied that taller trees had relatively higher uncertainties than shorter trees. Our findings also show that the accuracy for CBH estimation was the highest for black oak trees, with an RMSE of 0.52 m. The conifer species results were also good with uniformly high R 2 ranging from 0.82 to 0.93. In general, our method has demonstrated high accuracy for individual tree CBH estimation and strong potential for applications in mixed species over large areas.

Fire regimes, forest change, and self-organization in an old-growth mixed-conifer forest, Yosemite National Park, USA.

PubMed

Scholl, Andrew E; Taylor, Alan H

2010-03-01

Fire is recognized as a keystone process in dry mixed-conifer forests that have been altered by decades of fire suppression, Restoration of fire disturbance to these forests is a guiding principle of resource management in the U.S. National Park Service. Policy implementation is often hindered by a poor understanding of forest conditions before fire exclusion, the characteristics of forest changes since excluding fire, and the influence of topographic or self-organizing controls on forest structure. In this study the spatial and temporal characteristics of fire regimes and forest structure are reconstructed in a 2125-ha mixed-conifer forest. Forests were multi-aged, burned frequently at low severity and fire-return interval, and forest structure did not vary with slope aspect, elevation, or slope position. Fire exclusion has caused an increase in forest density and basal area and a compositional shift to shade-tolerant and fire-intolerant species. The median point fire-return interval and extent of a fire was 10 yr and 115 ha, respectively. The pre-Euro-American settlement fire rotation of 13 yr increased to 378 yr after 1905. The position of fire scars within tree rings indicates that 79% of fires burned in the midsummer to fall period. The spatial pattern of burns exhibited self-organizing behavior. Area burned was 10-fold greater when an area had not been burned by the previous fire. Fires were frequent and widespread, but patches of similar aged trees were < 0.2 ha, suggesting small fire-caused canopy openings. Managers need to apply multiple burns at short intervals for a sustained period to reduce surface fuels and create small canopy openings characteristic of the reference forest. By coupling explicit reference conditions with consideration of current conditions and projected climate change, management activities can balance restoration and risk management.

Thinning, tree-growth, and resistance to multi-year drought in a mixed-conifer forest of northern California

USGS Publications Warehouse

Vernon, Michael J.; Sherriff, Rosemary L.; van Mantgem, Phillip; Kane, Jeffrey M.

2018-01-01

Drought is an important stressor in forest ecosystems that can influence tree vigor and survival. In the U.S., forest managers use two primary management techniques to promote resistance and resilience to drought: prescribed fire and mechanical thinning. Generally applied to reduce fuels and fire hazard, treatments may also reduce competition for resources that may improve tree-growth and reduce mortality during drought. A recent severe and prolonged drought in California provided a natural experiment to investigate tree-growth responses to fuel treatments and climatic stress. We assessed tree-growth from 299 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) in treated and untreated stands during severe drought from 2012 to 2015 in the mixed-conifer forests of Whiskeytown National Recreation Area (WNRA) in northern California. The treatment implemented at WNRA removed 34% of live basal area through mechanical thinning with a subsequent pile burning of residual fuels. Tree-growth was positively associated with crown ratio and negatively associated with competition and a 1-year lag of climate water deficit, an index of drought. Douglas-fir generally had higher annual growth than ponderosa pine, although factors affecting growth were the same for both species. Drought resistance, expressed as the ratio between mean growth during drought and mean growth pre-drought, was higher in treated stands compared to untreated stands during both years of severe drought (2014 and 2015) for ponderosa pine but only one year (2014) for Douglas-fir. Thinning improved drought resistance, but tree size, competition and species influenced this response. On-going thinning treatments focused on fuels and fire hazard reduction are likely to be effective at promoting growth and greater drought resistance in dry mixed-conifer forests. Given the likelihood of future droughts, land managers may choose to implement similar treatments to reduce potential impacts.

Ectomycorrhizal Community Structure and Soil Characteristics of Mature Lodgepole Pine (Pinus Contorta) and Adjacent Stands of Old Growth Mixed Conifer in Yellowstone National Park, Wyoming USA

NASA Technical Reports Server (NTRS)

Douglas, Robert B.; Parker, V. Thomas; Cullings, Kenneth W.; Sun, Sidney (Technical Monitor)

2003-01-01

Forest development patterns following disturbance are known to influence the physical and chemical attributes of soils at different points in time. Changes in soil resources are thought to have a corresponding effect on ectomycorrhizal (ECM) community structure. We used molecular methods to compare below-ground ECM species richness, composition, and abundance between adjacent stands of homogenous lodgepole pine and old growth mixed conifer in Yellowstone National Park (YNP). In each stand-type we collected soil cores to both identify mycorrhizae and assess soil chemistry. Although no statistical difference was observed in the mean number of ECM root tips per core between stand types, the total number of species identified (85 versus 35) and the mean number of species per core (8.8 +/- 0.6 versus 2.5 +/- 0.3) were significantly higher in lodgepole pine. Differences between the actual and estimated species richness levels indicated that these forest types support a high number of ECM species and that undersampling was severe. Species compositions were widely disparate between stands where only four species were shared out of a total of 116. Soil analysis also revealed that mixed conifer was significantly lower in pH, but higher in organic matter, potassium, phosphorus, and ammonium when compared to lodgepole pine stands. Species richness per core was correlated with these chemical data, however, analysis of covariance indicated that stand type was the only statistically significant factor in the observed difference in species richness. Our data suggest that ECM fungal richness increases as homogenous lodgepole pine stands grow and mature, but declines after Engelmann spruce and subalpine fir colonize. Despite difficulties linking species composition with soil chemistry, there are a variety of physical and chemical factors that could be influencing ECM community structure. Future field experiments are necessary to test some of the mechanisms potentially operating within this system.

Monitoring phenology of photosynthesis in temperate evergreen and mixed deciduous forests using the normalized difference vegetation index (NDVI) and the photochemical reflectance index (PRI) at leaf and canopy scales

NASA Astrophysics Data System (ADS)

Wong, C. Y.; Arain, M. A.; Ensminger, I.

2016-12-01

Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which determines their phenology of high photosynthetic activity in the growing season and downregulation during the winter. Monitoring the timing of the transition between summer activity and winter downregulation in evergreens is difficult since this is a largely invisible process, unlike in deciduous trees that have a visible budding and a sequence of leaf unfolding in the spring and leaf abscission in the fall. The light-use efficiency (LUE) model estimates gross primary productivity (GPP) and may be parameterized using remotely sensed vegetation indices. Using spectral reflectance data, we derived the normalized difference vegetation index (NDVI), a measure of leaf "greenness", and the photochemical reflectance index (PRI), a proxy for chlorophyll:carotenoid ratios which is related to photosynthetic activity. To better understand the relationship between these vegetation indices and photosynthetic activity and to contrast this relationship between plant functional types, the phenology of NDVI, PRI and photosynthesis was monitored in an evergreen forest and a mixed deciduous forest at the leaf and canopy scale. Our data indicates that the LUE model can be parameterized by NDVI and PRI to track forest phenology. Differences in the sensitivity of PRI and NDVI will be discussed. These findings have implications to address the phenology of evergreen conifers by using PRI to complement NDVI in the LUE model, potentially improving model productivity estimates in northern hemisphere forests, that are dominated by conifers.

Patterns of mortality in a montane mixed-conifer forest in San Diego County, California.

PubMed

Freeman, Mary Pyott; Stow, Douglas A; An, Li

2017-10-01

We examine spatial patterns of conifer tree mortality and their changes over time for the montane mixed-conifer forests of San Diego County. These forest areas have recently experienced extensive tree mortality due to multiple factors. A spatial contextual image processing approach was utilized with high spatial resolution digital airborne imagery to map dead trees for the years 1997, 2000, 2002, and 2005 for three study areas: Palomar, Volcan, and Laguna mountains. Plot-based fieldwork was conducted to further assess mortality patterns. Mean mortality remained static from 1997 to 2002 (4, 2.2, and 4.2 trees/ha for Palomar, Volcan, and Laguna) and then increased by 2005 to 10.3, 9.7, and 5.2 trees/ha, respectively. The increase in mortality between 2002 and 2005 represents the temporal pattern of a discrete disturbance event, attributable to the 2002-2003 drought. Dead trees are significantly clustered for all dates, based on spatial cluster analysis, indicating that they form distinct groups, as opposed to spatially random single dead trees. Other tests indicate no directional shift or spread of mortality over time, but rather an increase in density. While general temporal and spatial mortality processes are uniform across all study areas, the plot-based species and quantity distribution of mortality, and diameter distributions of dead vs. living trees, vary by study area. The results of this study improve our understanding of stand- to landscape-level forest structure and dynamics, particularly by examining them from the multiple perspectives of field and remotely sensed data. © 2017 by the Ecological Society of America.

Contrasting Spatial Patterns in Active-Fire and Fire-Suppressed Mediterranean Climate Old-Growth Mixed Conifer Forests

PubMed Central

Fry, Danny L.; Stephens, Scott L.; Collins, Brandon M.; North, Malcolm P.; Franco-Vizcaíno, Ernesto; Gill, Samantha J.

2014-01-01

In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbance regimes and climate. In this study, we characterize tree spatial patterns using four-ha stem maps from four old-growth, Jeffrey pine-mixed conifer forests, two with active-fire regimes in northwestern Mexico and two that experienced fire exclusion in the southern Sierra Nevada. Most of the trees were in patches, averaging six to 11 trees per patch at 0.007 to 0.014 ha−1, and occupied 27–46% of the study areas. Average canopy gap sizes (0.04 ha) covering 11–20% of the area were not significantly different among sites. The putative main effects of fire exclusion were higher densities of single trees in smaller size classes, larger proportion of trees (≥56%) in large patches (≥10 trees), and decreases in spatial complexity. While a homogenization of forest structure has been a typical result from fire exclusion, some similarities in patch, single tree, and gap attributes were maintained at these sites. These within-stand descriptions provide spatially relevant benchmarks from which to manage for structural heterogeneity in frequent-fire forest types. PMID:24586472

Modeled forest inventory data suggest climate benefits from fuels management

Treesearch

Jeremy S. Fried; Theresa B. Jain; Jonathan. Sandquist

2013-01-01

As part of a recent synthesis addressing fuel management in dry, mixed-conifer forests we analyzed more than 5,000 Forest Inventory and Analysis (FIA) plots, a probability sample that represents 33 million acres of these forests throughout Washington, Oregon, Idaho, Montana, Utah, and extreme northern California. We relied on the BioSum analysis framework that...

Mechanical fuel treatment effects on vegetation in a New Mexico dry mixed conifer forest

Treesearch

Glenn J. Mason; Terrell T. Baker; Douglas S. Cram; Jon C. Boren; Alexander G. Fernald; Dawn M. VanLeeuwen

2009-01-01

While the main objective of many silvicultural treatments in the western US is to reduce fire potential, their effects on overstory regeneration, midstory and herbaceous communities is of importance to land managers. To quantify these effects, we measured overstory regeneration, midstory density by species, herbaceous biomass, species richness and cover in commercial...

Chapter 15: A desired future condition for Sierra Nevada Forests

Treesearch

M. North

2012-01-01

An unexpected outcome of U.S. Forest Service General Technical Report PSW-GTR 220, "An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests" (North et al. 2009), was how it generated discussion about a desired future condition for Sierra Nevada forests. The paper did not convey leading-edge research results or provide an exhaustive literature...

Mechanical restoration of California mixed-conifer forests: does it matter which trees are cut?

Treesearch

Jessica Miesel; Ralph Boerner; Carl Skinner

2009-01-01

The montane ecosystems of northern California have been subjected to repeated manipulation and active fire suppression for over a century, resulting in changes in community structure that contribute to increased wildfire hazard. Ecosystem restoration via reduction of stand density for wildfire hazard mitigation has received substantial attention in recent years;...

Restoring composition and structure in Southwestern frequent-fire forests: A science-based framework for improving ecosystem resiliency

Treesearch

Richard T. Reynolds; Andrew J. Sanchez Meador; James A. Youtz; Tessa Nicolet; Megan S. Matonis; Patrick L. Jackson; Donald G. DeLorenzo; Andrew D. Graves

2013-01-01

Ponderosa pine and dry mixed-conifer forests in the Southwest United States are experiencing, or have become increasingly susceptible to, large-scale severe wildfire, insect, and disease episodes resulting in altered plant and animal demographics, reduced productivity and biodiversity, and impaired ecosystem processes and functions. We present a management framework...

Long-term demography of the Northern Goshawk in a variable environment

Treesearch

Richard T. Reynolds; Jeffrey S. Lambert; Curtis H. Flather; Gary C. White; Benjamin J. Bird; L. Scott Baggett; Carrie Lambert; Shelley Bayard De Bolo

2017-01-01

The Nearctic northern goshawk (Accipiter gentilis atricapillis) is a resident of conifer, broadleaf, and mixed forests from the boreal to the southwestern montane regions of North America. We report on a 20-year mark-recapture investigation (1991-2010) of the distribution and density of breeders, temporal and spatial variability in breeding, nestling sex ratios, local...

Empirical and simulated critical loads for nitrogen deposition in California mixed conifer forests

Treesearch

M.E. Fenn; S. Jovan; F. Yuan; L. Geiser; T. Meixner; B.S. Gimeno

2008-01-01

Empirical critical loads (CL) for N deposition were determined from changes in epiphytic lichen communities, elevated NO3 leaching in streamwater, and reduced fine root biomass in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) at sites with varying N deposition. The CL for lichen community impacts of 3.1 kg ha-1 year

Precipitation drives interannual variation in summer soil respiration in a Mediterranean-climate, mixed-conifer forest

Treesearch

M. Concilio; J. Chen; S. Ma; M. North

2009-01-01

Predictions of future climate change rely on models of how both environmental conditions and disturbance impact carbon cycling at various temporal and spatial scales. Few multi-year studies, however, have examined how carbon efflux is affected by the interaction of disturbance and interannual climate variation. We measured daytime soil respiration (R...