Canopy Density Mapping on Ultracam-D Aerial Imagery in Zagros Woodlands, Iran

Science.gov (United States)

Erfanifard, Y.; Khodaee, Z.

2013-09-01

Canopy density maps express different characteristics of forest stands, especially in woodlands. Obtaining such maps by field measurements is so expensive and time-consuming. It seems necessary to find suitable techniques to produce these maps to be used in sustainable management of woodland ecosystems. In this research, a robust procedure was suggested to obtain these maps by very high spatial resolution aerial imagery. It was aimed to produce canopy density maps by UltraCam-D aerial imagery, newly taken in Zagros woodlands by Iran National Geographic Organization (NGO), in this study. A 30 ha plot of Persian oak (Quercus persica) coppice trees was selected in Zagros woodlands, Iran. The very high spatial resolution aerial imagery of the plot purchased from NGO, was classified by kNN technique and the tree crowns were extracted precisely. The canopy density was determined in each cell of different meshes with different sizes overlaid on the study area map. The accuracy of the final maps was investigated by the ground truth obtained by complete field measurements. The results showed that the proposed method of obtaining canopy density maps was efficient enough in the study area. The final canopy density map obtained by a mesh with 30 Ar (3000 m2) cell size had 80% overall accuracy and 0.61 KHAT coefficient of agreement which shows a great agreement with the observed samples. This method can also be tested in other case studies to reveal its capability in canopy density map production in woodlands.

Ecology and management of oak woodlands and savannas in the southwestern Borderlands Region

Science.gov (United States)

Gerald J. Gottfried; Peter F. Ffolliott

2013-01-01

Management of the Madrean oak woodlands and the less dense and ecologically different oak savannas must be based on sound ecological information. However, relatively little is known about the Madrean oak ecosystems in spite of the fact that they cover about 80,000 km2 in the southwestern United States and northern Mexico. Emory oak (Quercus emoryi), the dominant tree...

As Long as it is Not My Land: Landowners and Oak Woodland Conservation in Spain and California

Science.gov (United States)

Huntsinger, L.; Oviedo, J. L.; Plieninger, T.

2009-04-01

In Spain and California, landowners have a crucial role to play in the conservation of oak woodlands. The value of environmental services from private oak woodlands used for extensive agriculture has drawn the attention of policymakers and conservationists, and policy strategies for maintenance of traditional extensive agriculture are emergent in both places. These strategies require landowner participation. Surveys of landowners in each place reveal similarities in management practices, goals, attitudes, and demographics, as well as some interesting points of divergence. Despite very different institutional and political contexts, landowner attitudes show some striking similarities. Both favor a degree of government protection of natural resources, but would prefer that this would not include regulation of activities on their own lands. With a relatively stable woodland ecologically, and a high rate of urban out-migration into woodland areas, the more visible initiatives in California today focus on landowner education, and tax relief for temporary or permanent restrictions on land conversion. Non-governmental organizations have taken an increasingly visible role in the brokering of purchased or donated land title restrictions for conservation. These programs have resulted in an apparent decline in oak harvest and some limitations on development, but have not often directly influenced regeneration or management on private lands. In contrast, with more stable patterns of population distribution and less stable woodland ecological dynamics, Spanish incentive programs approach regeneration and management issues more directly, with subsidies for oak planting and maintenance, and price advantages for the products of traditional agriculture. The results of a twenty-year longitudinal study in California show a shift towards an increasing focus on amenities by California oak woodland landowners, whether they are ranch owners with hundreds of hectares of woodland, or

Wildlife diversity of restored shortleaf pine-oak woodlands in the northern Ozarks

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Corinne S. Mann; Andrew R. Forbes

2007-01-01

Historic changes in land use have altered the plant composition and structure of shortleaf pine-oak woodlands in the northern Ozarks. As a result, the composition of wildlife communities in these landscapes has shifted to species that are more associated with closed canopy oak forests. For example, the red-cockaded woodpecker (Picoides borealis) has...

The Influence of Epiphytic Lichens on the Nutrient Cycling of a Blue Oak Woodland

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Johannes M. Knops; Thomas H. H. Nash III; William H. Schlesinger

1997-01-01

We evaluated the importance of epiphytic lichens in the nutrient cycling of a blue oak (Quercus douglasii) woodland in California. Each oak tree contained an average of 3.8 kg lichen biomass, totaling 590 kg per ha. For comparison, oak leaf biomass was 958 kg per ha. We compared tree growth, volume and composition of throughfall (rainfall falling...

Income value of private amenities assessed in California oak woodlands

Directory of Open Access Journals (Sweden)

Jose L. Oviedo

2012-07-01

Full Text Available Landowners in California were surveyed using a contingent valuation technique to assess its usefulness in estimating the monetary income value of private amenities from their oak woodland properties. Private amenities - such as recreation, scenic beauty and a rural lifestyle - are considered an important influence on rangeland owners, but few studies have attempted to place a monetary income value on them. Landowners were asked to estimate the maximum amount of earnings that they were willing to forgo before selling their property to invest in more commercially profitable, nonagrarian assets, and the proportion of the land price that they thought was explained by private amenities from their land. On average, landowners were willing to pay $54 per acre annually for private amenities, and they attributed 57% of the land price to them. Regression analysis revealed that the landowners' willingness to pay per acre decreased as property size increased. This approach sheds light on how landowners value the benefits of land owner-ship and offers insights for outreach and policy development for privately owned oak woodlands.

Effects of declining oak vitality on ecosystem functions: Lessons from a Spanish oak woodland

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López-Sánchez, Aida; Bareth, Georg; Bolten, Andreas; Linstädter, Anja

2017-04-01

Mediterranean oak woodlands have a great ecological and socio-economic importance. Today, these fragile ecosystems are facing unprecedented degradation threats from Novel Oak Diseases (NODs). Among NOD drivers, maladapted land management practices and climate change are most important. Although it is generally believed that NOD-related declines in tree vitality will have detrimental effects on ecosystem functions, little is known on the magnitude of change, and whether different functions are affected in a similar way. Here we analyzed effects of tree vitality on various ecosystem functions, comparing subcanopy and intercanopy habitats across two oak species (Quercus ilex and Q. suber) in a Spanish oak woodland. We asked how functions - including aboveground net primary productivity (ANPP), taxonomic diversity, and litter decomposition rates - were affected by oak trees' size and vitality. We also combined measurements in the ecosystem function habitat index (MEFHI), a proxy of ecosystem multifunctionality. Field research was carried out in 2016 on a dehesa in southern Spain. We used a stratified random sampling to contrast trees of different species affiliation, size and vitality. Tree vitality was estimated as crown density (assessed via hemispherical photography), and as tree vigor, which combines the grade of canopy defoliation with proxies for tree size (dbh, height, crown height and crown radius). For each tree (n = 34), two plots (50 x 50 cm) were located; one in the subcanopy habitat, and the other in the intercanopy area beyond the tree crown's influence. On all 68 plots, moveable cages were placed during the main growth period (March to May) to estimate ANPP under grazed conditions. Litter decomposition rates were assessed via the tea bag index. ANPP and the biomass of grasses, forbs and legumes were recorded via destructive sampling. To take plots' highly variable environmental conditions into account, we recorded a suite of abiotic and biotic

Modeling the effectiveness of tree planting to mitigate habitat loss in blue oak woodlands

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Richard B. Standiford; Douglas McCreary; William Frost

2002-01-01

Many local conservation policies have attempted to mitigate the loss of oak woodland habitat resulting from conversion to urban or intensive agricultural land uses through tree planting. This paper models the development of blue oak (Quercus douglasii) stand structure attributes over 50 years after planting. The model uses a single tree, distance...

Nitrogen dynamics of spring-fed wetland ecosystems of the Sierra Nevada foothills oak woodland

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Randall D. Jackson; Barbara Allen-Diaz

2002-01-01

Spring-fed wetlands are small, highly productive, patchy ecosystems nested within the oak woodland/annual grassland matrix of the Sierra Nevada foothills. In an effort to place these wetlands in a landscape context, we described seasonal variation (1999-2000 growing season) in nitrogen cycling parameters at 6 spring-fed wetland sites of the Sierra Nevada foothill oak...

Restoring oak forest, woodlands and savannahs using modern silvicultural analogs to historic cultural fire regimes

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Daniel C. Dey; Richard P. Guyette; Callie J. Schweitzer; Michael C. Stambaugh; John M. Kabrick

2015-01-01

Variability in historic fire regimes in eastern North America resulted in an array of oak savannahs, woodlands and forests that were dominant vegetation types throughout the region. In the past century, once abundant savannahs and woodlands have become scarce due to conversion to agriculture, or development of forest structure in the absence of fire. In addition, the...

Plant composition in oak savanna and woodland restoration at Prairie Fork Conservation Area in Missouri

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Nadia E. Navarrete-Tindall; J.W. Van Sambeek; Jamie Coe; Warren Taylor

2007-01-01

The wooded areas of the Prairie Fork Conservation Area in central Missouri are typical of the oak/hickory forest/prairie transition zone that will require active management to restore pre-settlement, grass dominated savannas and open woodlands to improve habitat for wildlife. We initiated a management program to restore savannas and woodlands by reducing the midstory (...

Oak woodland restoration in the Missouri Ozarks: two case studies examining responses of ground flora vegetation to prescribed fire

Science.gov (United States)

Aaron P. Stevenson

2016-01-01

Prescribed fire and thinning are two primary tools for restoring overgrown oak and oak-pine woodlands in Missouri. We wanted to examine woodland restoration efforts and determine if we were meeting our goals of promoting herbaceous ground flora cover and richness. We examined herbaceous responses to fire at two restoration sites in the Missouri Ozarks. At the first...

Proceedings of a symposium on oak woodlands: ecology, management, and urban interface issues; 19–22 March 1996; San Luis Obispo, CA

Science.gov (United States)

Norman H. Pillsbury; Jared Verner; William D. Tietje

1997-01-01

Oak woodlands, the predominant vegetation type in the most inhabitable areas of California, comprise 10 million acres in the State and have been used primarily for livestock production. Today, residential intrusion into oak woodlands results in habitat fragmentation and degradation of economic, esthetic, and ecological values. Decision makers must face up to the...

Landowner total income from oak woodland working landscapes in Spain and California

Science.gov (United States)

Jose L. Oviedo; Lynn Huntsinger; Pablo Campos

2015-01-01

Conventional accounting of agricultural income focuses on the commercial operating income from oak woodland ranches, omitting the value of amenities to the landowner and real capital gains, which includes land revaluation (appreciation). These accounting exercises also mix income earned through self-employed (landowner and household) labor with ranch operating income,...

Woodland salamander responses to a shelterwood harvest-prescribed burn silvicultural treatment within Appalachian mixed-oak forests

Science.gov (United States)

Ford, W. Mark; Mahoney, Kathleen R.; Russell, Kevin R.; Rodrigue, Jane L.; Riddle, Jason D.; Schuler, Thomas M.; Adams, Mary Beth

2015-01-01

Forest management practices that mimic natural canopy disturbances, including prescribed fire and timber harvests, may reduce competition and facilitate establishment of favorable vegetative species within various ecosystems. Fire suppression in the central Appalachian region for almost a century has contributed to a transition from oak-dominated to more mesophytic, fire-intolerant forest communities. Prescribed fire coupled with timber removal is currently implemented to aid in oak regeneration and establishment but responses of woodland salamanders to this complex silvicultural system is poorly documented. The purpose of our research was to determine how woodland salamanders respond to shelterwood harvests following successive burns in a central Appalachian mixed-oak forest. Woodland salamanders were surveyed using coverboard arrays in May, July, and August–September 2011 and 2012. Surveys were conducted within fenced shelterwood-burn (prescribed fires, shelterwood harvest, and fencing to prevent white-tailed deer [Odocoileus virginianus] herbivory), shelterwood-burn (prescribed fires and shelterwood harvest), and control plots. Relative abundance was modeled in relation to habitat variables measured within treatments for mountain dusky salamanders (Desmognathus ochrophaeus), slimy salamanders (Plethodon glutinosus), and eastern red-backed salamanders (Plethodon cinereus). Mountain dusky salamander relative abundance was positively associated with canopy cover and there were significantly more individuals within controls than either shelterwood-burn or fenced shelterwood-burn treatments. Conversely, habitat variables associated with slimy salamanders and eastern red-backed salamanders did not differ among treatments. Salamander age-class structure within controls did not differ from shelterwood-burn or fenced shelterwood-burn treatments for any species. Overall, the woodland salamander assemblage remained relatively intact throughout the shelterwoodburn

How can prescribed burning and harvesting restore shortleaf pine-oak woodland at the landscape scale in central United States? Modeling joint effects of harvest and fire regimes

Science.gov (United States)

Wenchi Jin; Hong S. He; Stephen R. Shifley; Wen J. Wang; John M. Kabrick; Brian K. Davidson

2018-01-01

Historical fire regimes in the central United States maintained open-canopy shortleaf pine-oak woodlands on xeric sites. Following large-scale harvest and fire suppression, those woodlands grew denser with more continuous canopy cover, and they gained mesic species at the expense of shortleaf pine. There is high interest in restoring shortleaf pine-oak woodlands; most...

Monitoring Values and Practices of Oak Woodland Decision Makers on the Urban Fringe

Science.gov (United States)

William Stewart

1991-01-01

Concern over oak woodlands has shifted away from ranch management towards residential areas. This shift has been accompanied by the involvement of decision makers who previously had little involvement with rangeland policies and practices. A survey of three recent Cooperative Extension workshops illustrates a number of important patterns regarding interest and...

Population genetics and biological control of goldspotted oak borer, an invasive pest of California oaks

Science.gov (United States)

Vanessa Lopez; Paul F. Rugman-Jones; Tom W. Coleman; Richard Stouthamer; Mark Hoddle

2015-01-01

California’s oak woodlands are threatened by the recent introduction of goldspotted oak borer (Agrilus auroguttatus). This invasive wood-borer is indigenous to mountain ranges in southern Arizona where its low population densities may be due to the presence of co-evolved, host-specific natural enemies. Reuniting A. auroguttatus...

People and oaks

Science.gov (United States)

Paul F. Starrs

2015-01-01

While technical knowledge of oaks, acorns, habitat, wildlife, and woodland environments is evolving and a sought-after field of study, there are profound linkages, at once humanistic and artistic, where it comes to people and oaks. Looking at six distinct facets of humans and oak woodlands, this essay suggests that the bonds of people to place can be mediated by the...

Severe dry winter affects plant phenology and carbon balance of a cork oak woodland understorey

Science.gov (United States)

Correia, A. C.; Costa-e-Silva, F.; Dubbert, M.; Piayda, A.; Pereira, J. S.

2016-10-01

Mediterranean climates are prone to a great variation in yearly precipitation. The effects on ecosystem will depend on the severity and timing of droughts. In this study we questioned how an extreme dry winter affects the carbon flux in the understorey of a cork oak woodland? What is the seasonal contribution of understorey vegetation to ecosystem productivity? We used closed-system portable chambers to measure CO2 exchange of the dominant shrub species (Cistus salviifolius, Cistus crispus and Ulex airensis), of the herbaceous layer and on bare soil in a cork oak woodland in central Portugal during the dry winter year of 2012. Shoot growth, leaf shedding, flower and fruit setting, above and belowground plant biomass were measured as well as seasonal leaf water potential. Eddy-covariance and micrometeorological data together with CO2 exchange measurements were used to access the understorey species contribution to ecosystem gross primary productivity (GPP). The herbaceous layer productivity was severely affected by the dry winter, with half of the yearly maximum aboveground biomass in comparison with the 6 years site average. The semi-deciduous and evergreen shrubs showed desynchronized phenophases and lagged carbon uptake maxima. Whereas shallow-root shrubs exhibited opportunistic characteristics in exploiting the understorey light and water resources, deep rooted shrubs showed better water status but considerably lower assimilation rates. The contribution of understorey vegetation to ecosystem GPP was lower during summer with 14% and maximum during late spring, concomitantly with the lowest tree productivity due to tree canopy renewal. The herbaceous vegetation contribution to ecosystem GPP never exceeded 6% during this dry year stressing its sensitivity to winter and spring precipitation. Although shrubs are more resilient to precipitation variability when compared with the herbaceous vegetation, the contribution of the understorey vegetation to ecosystem GPP can

Facilitation of Quercus ilex recruitment by shrubs in Mediterranean open woodlands

NARCIS (Netherlands)

Smit, Christian; den Ouden, Jan; Diaz, Mario

Question: Insufficient tree regeneration threatens the long-term persistence of biodiverse Mediterranean open oak woodlands. Could shrubs, scarce due to decades of management ( clearing and ploughing), facilitate holm oak recruitment at both acorn and seedling stages? Location: Open oak woodlands in

Facilitation of Quercus ilex recruitment by shrubs in Mediterranean open woodlands

NARCIS (Netherlands)

Smit, C.; Ouden, den J.; Diaz, M.

2008-01-01

Question: Insufficient tree regeneration threatens the long-term persistence of biodiverse Mediterranean open oak woodlands. Could shrubs, scarce due to decades of management (clearing and ploughing), facilitate holm oak recruitment at both acorn and seedling stages? Location: Open oak woodlands in

An accidental resource: the social ecological system framework applied to small wetlands in Sierran foothill oak woodlands

Science.gov (United States)

Tracy V. Hruska; Lynn Huntsinger; Jose L. Oviedo

2015-01-01

An ongoing study of the small wetlands in the northern Sierra Nevada foothill oak woodlands that provide habitat for the state-threatened California black rail (Laterallus jamaicensis coturniculus) offers an example of the way that the social ecological systems (SES) framework can be used to analyze a natural resource problem. At the outset, it was...

Stereo photo series for quantifying natural fuels.Volume XIII: grasslands, shrublands, oak-bay woodlands, and eucalyptus forests in the East Bay of California.

Science.gov (United States)

Clinton S. Wright; Robert E. Vihnanek

2014-01-01

Four series of photographs display a range of natural conditions and fuel loadings for grassland, shrubland, oak-bay woodland, and eucalyptus forest ecosystems on the eastern slopes of the San Francisco Bay area of California. Each group of photos includes inventory information summarizing vegetation composition, structure, and loading; woody material loading and...

Oak policy and management in California: Spanish origins and future considerations

Science.gov (United States)

James W. Bartolome; Lynn. Huntsinger

2015-01-01

The development of goals and policies for Californian oak woodlands is reviewed; then some important considerations for future policy development are highlighted. California and Spain share long and illuminating histories of human interaction with oak woodlands. The Integrated Hardwood Range Management Program, initiated about 1985, was a focal point for Californian...

A Spectral Evaluation of Models Performances in Mediterranean Oak Woodlands

Science.gov (United States)

Vargas, R.; Baldocchi, D. D.; Abramowitz, G.; Carrara, A.; Correia, A.; Kobayashi, H.; Papale, D.; Pearson, D.; Pereira, J.; Piao, S.; Rambal, S.; Sonnentag, O.

2009-12-01

Ecosystem processes are influenced by climatic trends at multiple temporal scales including diel patterns and other mid-term climatic modes, such as interannual and seasonal variability. Because interactions between biophysical components of ecosystem processes are complex, it is important to test how models perform in frequency (e.g. hours, days, weeks, months, years) and time (i.e. day of the year) domains in addition to traditional tests of annual or monthly sums. Here we present a spectral evaluation using wavelet time series analysis of model performance in seven Mediterranean Oak Woodlands that encompass three deciduous and four evergreen sites. We tested the performance of five models (CABLE, ORCHIDEE, BEPS, Biome-BGC, and JULES) on measured variables of gross primary production (GPP) and evapotranspiration (ET). In general, model performance fails at intermediate periods (e.g. weeks to months) likely because these models do not represent the water pulse dynamics that influence GPP and ET at these Mediterranean systems. To improve the performance of a model it is critical to identify first where and when the model fails. Only by identifying where a model fails we can improve the model performance and use them as prognostic tools and to generate further hypotheses that can be tested by new experiments and measurements.

Fire in upper Midwestern oak forest ecosystems: an oak forest restoration and management handbook

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Lee E. Frelich; Peter B. Reich; David W. Peterson

2015-01-01

We reviewed the literature to synthesize what is known about the use of fire to maintain and restore oak forests, woodlands, and savannas of the upper Midwestern United States, with emphasis on Minnesota, Wisconsin, and Michigan. Included are (1) known physical and ecological effects of fire on oaks from acorn through seedling, established sapling, and mature stages of...

Environmental and microbial factors influencing methane and nitrous oxide fluxes in Mediterranean cork oak woodlands: trees make a difference.

Science.gov (United States)

Shvaleva, Alla; Siljanen, Henri M P; Correia, Alexandra; Costa E Silva, Filipe; Lamprecht, Richard E; Lobo-do-Vale, Raquel; Bicho, Catarina; Fangueiro, David; Anderson, Margaret; Pereira, João S; Chaves, Maria M; Cruz, Cristina; Martikainen, Pertti J

2015-01-01

Cork oak woodlands (montado) are agroforestry systems distributed all over the Mediterranean basin with a very important social, economic and ecological value. A generalized cork oak decline has been occurring in the last decades jeopardizing its future sustainability. It is unknown how loss of tree cover affects microbial processes that are consuming greenhouse gases in the montado ecosystem. The study was conducted under two different conditions in the natural understory of a cork oak woodland in center Portugal: under tree canopy (UC) and open areas without trees (OA). Fluxes of methane and nitrous oxide were measured with a static chamber technique. In order to quantify methanotrophs and bacteria capable of nitrous oxide consumption, we used quantitative real-time PCR targeting the pmoA and nosZ genes encoding the subunit of particulate methane mono-oxygenase and catalytic subunit of the nitrous oxide reductase, respectively. A significant seasonal effect was found on CH4 and N2O fluxes and pmoA and nosZ gene abundance. Tree cover had no effect on methane fluxes; conversely, whereas the UC plots were net emitters of nitrous oxide, the loss of tree cover resulted in a shift in the emission pattern such that the OA plots were a net sink for nitrous oxide. In a seasonal time scale, the UC had higher gene abundance of Type I methanotrophs. Methane flux correlated negatively with abundance of Type I methanotrophs in the UC plots. Nitrous oxide flux correlated negatively with nosZ gene abundance at the OA plots in contrast to that at the UC plots. In the UC soil, soil organic matter had a positive effect on soil extracellular enzyme activities, which correlated positively with the N2O flux. Our results demonstrated that tree cover affects soil properties, key enzyme activities and abundance of microorganisms and, consequently net CH4 and N2O exchange.

Densities of Agrilus auroguttatus and Other Borers in California and Arizona Oaks

Directory of Open Access Journals (Sweden)

Laurel J. Haavik

2014-03-01

Full Text Available We investigated within-tree population density of a new invasive species in southern California, the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae, with respect to host species and the community of other borers present. We measured emergence hole densities of A. auroguttatus and other borers on the lower stem (bole of naïve oaks at 18 sites in southern California and on co-evolved oaks at seven sites in southeastern Arizona. We sampled recently dead oaks in an effort to quantify the community of primary and secondary borers associated with mortality—species that were likely to interact with A. auroguttatus. Red oaks (Section Lobatae produced greater densities of A. auroguttatus than white oaks (Section Quercus. On red oaks, A. auroguttatus significantly outnumbered native borers in California (mean ± SE of 9.6 ± 0.7 versus 4.5 ± 0.6 emergence holes per 0.09 m2 of bark surface, yet this was not the case in Arizona (0.9 ± 0.2 versus 1.1 ± 0.2 emergence holes per 0.09 m2. In California, a species that is taxonomically intermediate between red and white oaks, Quercus chrysolepis (Section Protobalanus, exhibited similar A. auroguttatus emergence densities compared with a co-occurring red oak, Q. kelloggii. As an invasive species in California, A. auroguttatus may affect the community of native borers (mainly Buprestidae and Cerambycidae that feed on the lower boles of oaks, although it remains unclear whether its impact will be positive or negative.

Life-cycle assessment of typical Portuguese cork oak woodlands.

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González-García, Sara; Dias, Ana Cláudia; Arroja, Luis

2013-05-01

Cork forest systems are responsible for making an important economic contribution to the Mediterranean region, especially Portugal where the cork oak woodlands or montados contain about 32% of the world's area. The environmental profile derived from reproduction cork production and extraction in two Portuguese regions (Tagus valley and Alentejo) representative of the Portuguese sector were assessed in detail using the Life-Cycle Assessment (LCA) methodology from a cradle-to-gate perspective. The production line was divided into four stages considering all the processes involved: stand establishment, stand management, cork stripping and field recovery. According to the environmental results, there were remarkable differences between the two production scenarios mainly due to the intensity and repetition of forest activities even though the cork yield was reported to be the same. The management system in the Alentejo region presented the worse environmental profile in almost all the impact categories under assessment, mainly due to the shorter cycle duration of the mechanical cleaning and pruning processes. Cork stripping was identified in both scenarios as the production stage with the highest contribution to the environmental profile due to the cleaning and pruning processes. A sensitivity assessment concerning the cork yield was performed since the average production yields in the Portuguese montados are lower than the ones used in this study. Thus, if the cork yield is reduced, the environmental profile in both scenarios gets worse since almost all the forest activities involved are the same. Copyright © 2013 Elsevier B.V. All rights reserved.

Restoration of midwestern oak woodlands and savannas

Science.gov (United States)

Dan C. Dey; John M. Kabrick

2015-01-01

There are various definitions for savanna and woodland in the ecological literature. Characteristic elements of each community are broadly defined and often overlap according to the authorities (Curtis 1959; Nuzzo 1986; Nelson 2010). Some confusion is inevitable when categorizing what is in reality a continuum of states from prairie to forest in which there can be much...

Predicting oak density with ecological, physical, and soil indicators

Science.gov (United States)

Callie Jo Schweitzer; Adrian A. Lesak; Yong Wang

2006-01-01

We predicted density of oak species in the mid-Cumberland Plateau region of northeastern Alabama on the basis of basal area of tree associations based on light tolerances, physical site characteristics, and soil type. Tree basal area was determined for four species groups: oaks (Quercus spp.), hickories (Carya spp.), yellow-poplar...

Differences in overland flow, hydrophobicity and soil moisture dynamics between Mediterranean woodland types in a peri-urban catchment in Portugal

Science.gov (United States)

Ferreira, C. S. S.; Walsh, R. P. D.; Shakesby, R. A.; Keizer, J. J.; Soares, D.; González-Pelayo, O.; Coelho, C. O. A.; Ferreira, A. J. D.

2016-02-01

Forest hydrology has been widely investigated, but the impacts of different woodland types on hydrological processes within a peri-urban catchment mosaic are poorly understood. This paper investigates overland flow generation processes in three different types of woodland in a small (6.2 km2) catchment in central Portugal that has undergone strong urban development over the past 50 years. A semi-natural oak stand and a sparse eucalyptus stand on partly abandoned peri-urban land and a dense eucalyptus plantation were each instrumented with three 16 m2 runoff plots and 15 throughfall gauges, which were monitored at c. 1- to 2-week intervals over two hydrological years. In addition, surface soil moisture content (0-5 cm) and hydrophobicity (0-2 cm, 2-5 cm and 5-7 cm) were measured at the same time as overland flow and throughfall. Although all three woodland types produced relatively little overland flow (woodland types. This contrast in overland flow can be attributed to infiltration-excess processes operating in storms following dry antecedent weather when severe hydrophobicity was widespread in the dense eucalypt plantation, whereas it was of moderate and low severity and less widespread in the sparse eucalypt and oak woodlands, respectively. In contrast, under wet conditions greater (albeit still small) percentages of overland flow were produced in oak woodland than in the two eucalypt plantations; this was probably linked to saturation-excess overland flow being generated more readily at the oak site as a result of its shallower soil. Differences in water retention in surface depressions affected overland flow generation and downslope flow transport. Implications of the seasonal differentials in overland flow generation between the three distinct woodland types for the hydrological response of peri-urban catchments are addressed.

Oak regeneration and overstory density in the Missouri Ozarks

Science.gov (United States)

David R. Larsen; Monte A. Metzger

1997-01-01

Reducing overstory density is a commonly recommended method of increasing the regeneration potential of oak (Quercus) forests. However, recommendations seldom specify the probable increase in density or the size of reproduction associated with a given residual overstory density. This paper presents logistic regression models that describe this...

Temporal dynamics of spectral bioindicators evidence biological and ecological differences among functional types in a cork oak open woodland

Science.gov (United States)

Cerasoli, Sofia; Costa e Silva, Filipe; Silva, João M. N.

2016-06-01

The application of spectral vegetation indices for the purpose of vegetation monitoring and modeling increased largely in recent years. Nonetheless, the interpretation of biophysical properties of vegetation through their spectral signature is still a challenging task. This is particularly true in Mediterranean oak forest characterized by a high spatial and temporal heterogeneity. In this study, the temporal dynamics of vegetation indices expected to be related with green biomass and photosynthetic efficiency were compared for the canopy of trees, the herbaceous layer, and two shrub species: cistus ( Cistus salviifolius) and ulex ( Ulex airensis). coexisting in a cork oak woodland. All indices were calculated from in situ measurements with a FieldSpec3 spectroradiometer (ASD Inc., Boulder, USA). Large differences emerged in the temporal trends and in the correlation between climate and vegetation indices. The relationship between spectral indices and temperature, radiation, and vapor pressure deficit for cork oak was opposite to that observed for the herbaceous layer and cistus. No correlation was observed between rainfall and vegetation indices in cork oak and ulex, but in the herbaceous layer and in the cistus, significant correlations were found. The analysis of spectral vegetation indices with fraction of absorbed PAR (fPAR) and quantum yield of chlorophyll fluorescence ( ΔF/ Fm') evidenced strongest relationships with the indices Normalized Difference Water Index (NDWI) and Photochemical Reflectance Index (PRI)512, respectively. Our results, while confirms the ability of spectral vegetation indices to represent temporal dynamics of biophysical properties of vegetation, evidence the importance to consider ecosystem composition for a correct ecological interpretation of results when the spatial resolution of observations includes different plant functional types.

Assessing Threats and Conservation Status of Historical Centers of Oak Richness in California

Directory of Open Access Journals (Sweden)

Kelly Jane Easterday

2016-12-01

Full Text Available Oak trees are emblematic of California landscapes, they serve as keystone cultural and ecological species and as indicators of natural biological diversity. As historically undeveloped landscapes are increasingly converted to urban environments, endemic oak woodland extent is reduced, which underscores the importance of strategic placement and reintroduction of oaks and woodland landscape for the maintenance of biodiversity and reduction of habitat fragmentation. This paper investigated the effects of human urban development on oak species in California by first modeling historical patterns of richness for eight oak tree species using historical map and plot data from the California Vegetation Type Mapping (VTM collection. We then examined spatial intersections between hot spots of historical oak richness and modern urban and conservation lands and found that impacts from development and conservation vary by both species and richness. Our findings suggest that the impact of urban development on oaks has been small within the areas of highest oak richness but that areas of highest oak richness are also poorly conserved. Third, we argue that current policy measures are inadequate to conserve oak woodlands and suggest regions to prioritize acquisition of conservation lands as well as examine urban regions where historic centers of oak richness were lost as potential frontiers for oak reintroduction. We argue that urban planning could benefit from the adoption of historical data and modern species distribution modelling techniques primarily used in natural resources and conservation fields to better locate hot spots of species richness, understand where habitats and species have been lost historically and use this evidence as incentive to recover what was lost and preserve what still exists. This adoption of historical data and modern techniques would then serve as a paradigm shift in the way Urban Planners recognize, quantify, and use landscape

Pathways for resilience in Mediterranean cork oak land use systems

NARCIS (Netherlands)

Acácio, V.C.; Holmgren, M.

2014-01-01

Context Loss of woodlands and degradation of vegetation and soil have been described for all Mediterranean-type ecosystems worldwide. In the Western Iberian Peninsula, overexploitation of evergreen cork oak land use systems has led to soil erosion, failures in oak recruitment, and loss of forests.

Firewood, food and human niche construction: the potential role of Mesolithic hunter-gatherers in actively structuring Scotland's woodlands

Science.gov (United States)

Bishop, Rosie R.; Church, Mike J.; Rowley-Conwy, Peter A.

2015-01-01

Over the past few decades the potential role of Mesolithic hunter-gatherers in actively constructing their own niches, through the management of wild plants, has frequently been discussed. It is probable that Mesolithic hunter-gatherers systematically exploited specific woodland resources for food and fuel and influenced the 'natural' abundance or distribution of particular species within Mesolithic environments. Though there has been considerable discussion of the pollen evidence for potential small-scale human-woodland manipulation in Mesolithic Scotland, the archaeobotanical evidence for anthropogenic firewood and food selection has not been discussed in this context. This paper assesses the evidence for the active role of Mesolithic hunter-gatherer communities in systematically exploiting and managing woodlands for food and fuel in Scotland. While taphonomic factors may have impacted on the frequency of specific species in archaeobotanical assemblages, it is suggested that hunter-gatherers in Mesolithic Scotland were systematically using woodland plants, and in particular hazel and oak, for food and fuel. It is argued that the pollen evidence for woodland management is equivocal, but hints at the role of hunter-gatherers in shaping the structure of their environments, through the maintenance or creation of woodland clearings for settlement or as part of vegetation management strategies. It is proposed that Mesolithic hunter-gatherers may have actively contributed to niche construction and that the systematic use of hazel and oak as a fuel may reflect the deliberate pruning of hazel trees to increase nut-yields and the inadvertent - or perhaps deliberate - coppicing of hazel and oak during greenwood collection.

ISOTHECIUM MYOSUROIDES AND THUIDIUM TAMARISCINUM MOSSES AS BIOINDICATORS OF NITROGEN AND HEAVY METAL DEPOSITION IN ATLANTIC OAK WOODLANDS

Directory of Open Access Journals (Sweden)

K. Wilkins

2015-04-01

Full Text Available Moss tissue chemistry is widely used as a bioindicator of atmospheric deposition. The objective of this study was to compare the tissue chemistry of two moss species in Irish Atlantic oak woodlands, Isothecium myosuroides [Im] and Thuidium tamariscinum [Tt], and to determine their relationship to indices of atmospheric deposition. Moss species were collected from twenty-two woodland sites during April 2013 and analysed for nitrogen, sulphur, and eleven heavy metals. Nitrogen content was significantly correlated between species (rs = 0.84, but their mean values (Im = 1.23%, Tt = 1.34% were significantly different. A simple linear regression suggested that nitrogen content was significantly related to atmospheric ammonia (R2 = 0.67 [Im], R2 = 0.65 [Tt] and total nitrogen deposition (R2 = 0.57 [Im], R2 = 0.54 [Tt]. Many heavy metals had significant interspecies correlations (Al, V, Ni, Cu, Zn, As, Sb, Pb; rs = 0.46−0.77. A few metals (As, Sb and Pb were positively correlated with easting and northing for both species, which may suggest transboundary or national industrial emissions sources. The results suggest that both species could be used as bioindicators of deposition for nitrogen and some heavy metals, although further study of the relationship between tissue concentrations and atmospheric deposition is warranted. Furthermore, interspecies calibration is required to use both species in conjunction.

Breeding bird response to juniper woodland expansion

Science.gov (United States)

Rosenstock, Steven S.; van Riper, Charles

2001-01-01

In recent times, pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands have expanded into large portions of the Southwest historically occupied by grassland vegetation. From 1997-1998, we studied responses of breeding birds to one-seed juniper (J. monosperma) woodland expansion at 2 grassland study areas in northern Arizona. We sampled breeding birds in 3 successional stages along a grassland-woodland gradient: un-invaded grassland, grassland undergoing early stages of juniper establishment, and developing woodland. Species composition varied greatly among successional stages and was most different between endpoints of the gradient. Ground-nesting grassland species predominated in uninvaded grassland but declined dramatically as tree density increased. Tree- and cavity-nesting species increased with tree density and were most abundant in developing woodland. Restoration of juniper-invaded grasslands will benefit grassland-obligate birds and other wildlife.

Abundance of birds in the oak savannas of the southwestern United States

Science.gov (United States)

Wendy D. Jones; Carlton M. Jones; Peter F. Ffolliott; Gerald J. Gottfried

2005-01-01

Oak ecosystems of the Southwestern United States are important habitats for a variety of wildlife species. Information is available on the abundance and habitat preferences of some species inhabiting the more densely structured oak woodlands, but little information is available on these topics for the comparatively open oak savannas. Studies are underway to alleviate...

Working and Learning Among California Oaks

Science.gov (United States)

Tietje, B.; Gingg, B.; Zingo, J.; Huntsinger, L.

2009-04-01

With tremendous support from collaborators and enthusiastic volunteers, "Learning Among the Oaks" at the historic Santa Margarita Ranch has become a favorite outdoor learning experience for hundreds of Santa Margarita School students, along with their teachers and families. Oaks are at the center of this unique and cost effective public education program. From getting to know local oaks to exploring conservation issues within the context of a historic working cattle ranch, students take pride in expanding their awareness and knowledge of the local oak woodland community. Santa Margarita School families representing the varied demographics of the community come together on the trail. For many, the program provides a first opportunity to get to know those who make a living on the land and to understand that this land around their school is more than a pretty view. "Learning Among the Oaks" also addresses the need for quality, hands-on science activities and opportunities to connect children with the outdoor world. Using a thematic approach and correlating lessons with State Science Standards, we've engaged students in a full-spectrum of exciting outdoor learning adventures. As students progress through the grades, they find new challenges within the oak trail environment. We've succeeded in establishing an internship program that brings highly qualified, enthusiastic university students out to practice their science teaching skills while working with elementary school students. In the future, these university student interns may assist with the development of interpretive displays, after-school nature activities and monitoring projects. We've benefited from proximity to Cal Poly State University and its "learn-by-doing" philosophy. We've also succeeded in building a dedicated network of volunteers and collaborators, each with a special interest satisfied through participation in the oak trail program. While "Learning Among the Oaks" has focused on educating school

Influence of tree canopy on N{sub 2} fixation by pasture legumes and soil rhizobial abundance in Mediterranean oak woodlands

Energy Technology Data Exchange (ETDEWEB)

Carranca, C., E-mail: corina.carranca@iniav.pt [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Castro, I.V.; Figueiredo, N. [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Redondo, R. [Laboratorio de Isotopos Estables, Universidade Autonoma, Madrid (Spain); Rodrigues, A.R.F. [Centro de Estudos Florestais, ISA/UL, Tapada Ajuda, 1349-017 Lisboa (Portugal); Saraiva, I.; Maricato, R. [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Madeira, M.A.V. [Centro de Estudos Florestais, ISA/UL, Tapada Ajuda, 1349-017 Lisboa (Portugal)

2015-02-15

Symbiotic N{sub 2} fixation is of primordial significance in sustainable agro-forestry management as it allows reducing the use of mineral N in the production of mixed stands and by protecting the soils from degradation. Thereby, on a 2-year basis, N{sub 2} fixation was evaluated in four oak woodlands under Mediterranean conditions using a split-plot design and three replicates. {sup 15}N technique was used for determination of N{sub 2} fixation rate. Variations in environmental conditions (temperature, rainfall, radiation) by the cork tree canopy as well as the age of stands and pasture management can cause great differences in vegetation growth, legume N{sub 2} fixation, and soil rhizobial abundance. In the present study, non-legumes dominated the swards, in particular beneath the tree canopy, and legumes represented only 42% of total herbage. A 2-fold biomass reduction was observed in the oldest sown pasture in relation to the medium-age sward (6 t DW ha{sup −1} yr{sup −1}). Overall, competition of pasture growth for light was negligible, but soil rhizobial abundance and symbiotic N{sub 2} fixation capacity were highly favored by this environmental factor in the spring and outside the influence of tree canopy. Nitrogen derived from the atmosphere was moderate to high (54–72%) in unsown and sown swards. Inputs of fixed N2 increased from winter to spring due to more favorable climatic conditions (temperature and light intensity) for both rhizobia and vegetation growths. Assuming a constant fixation rate at each seasonal period, N{sub 2} fixation capacity increased from about 0.10 kg N ha{sup −1} per day in the autumn–winter period to 0.15 kg N ha{sup −1} per day in spring. Belowground plant material contributed to 11% of accumulated N in pasture legumes and was not affected by canopy. Size of soil fixing bacteria contributed little to explain pasture legumes N. - Highlights: • Legumes fixation in oak woodlands was quantified in terms of biomass and N

Wildfire patterns and landscape changes in Mediterranean oak woodlands.

Science.gov (United States)

Guiomar, N; Godinho, S; Fernandes, P M; Machado, R; Neves, N; Fernandes, J P

2015-12-01

Fire is infrequent in the oak woodlands of southern Portugal (montado) but large and severe fires affected these agro-forestry systems in 2003-2005. We hypothesised transition from forest to shrubland as a fire-driven process and investigated the links between fire incidence and montado change to other land cover types, particularly those related with the presence of pioneer communities (generically designed in this context as "transitions to early-successional communities"). We present a landscape-scale framework for assessing the probability of transition from montado to pioneer communities, considering three sets of explanatory variables: montado patterns in 1990 and prior changes from montado to early-successional communities (occurred between 1960 and 1990), fire patterns, and spatial factors. These three sets of factors captured 78.2% of the observed variability in the transitions from montado to pioneer vegetation. The contributions of fire patterns and spatial factors were high, respectively 60.6% and 43.4%, the influence of montado patterns and former changes in montado being lower (34.4%). The highest amount of explained variation in the occurrence of transitions from montado to early-successional communities was related to the pure effect of fire patterns (19.9%). Low spatial connectedness in montado landscape can increase vulnerability to changes, namely to pioneer vegetation, but the observed changes were mostly explained by fire characteristics and spatial factors. Among all metrics used to characterize fire patterns and extent, effective mesh size provided the best modelling results. Transitions from montado to pioneer communities are more likely in the presence of high values of the effective mesh size of total burned area. This cross-boundary metric is an indicator of the influence of large fires in the distribution of the identified transitions and, therefore, we conclude that the occurrence of large fires in montado increases its probability of

Effects of fire and browsing on regeneration of blue oak

Science.gov (United States)

James W. Bartolome; Mitchel P. McClaran; Barbara H. Allen-Diaz; Jim Dunne; Lawrence D. Ford; Richard B. Standiford; Neil K. McDougald; Larry C. Forero

2002-01-01

Blue oaks (Quercus douglasii) are not regenerating well over much of California. The roles of fire and browsing in regeneration are probably significant, but poorly understood. We burned two foothill blue oak woodland sites which contained significant numbers of small trees between 40 and 70 cm tall, then compared height growth over 14 years among 48...

Shifts in soil fungal communities in Tuber melanosporum plantations over a 20-year transition from agriculture fields to oak woodlands

Energy Technology Data Exchange (ETDEWEB)

Bing, L.; Fischer, C.R.; Bonet, J.A.; Castaño, C.; Colinas, C.

2016-07-01

Aim of study: To explore the diversity of soil fungi found in black truffle (Tuber melanosporum) plantations following the introduction of the mycorrhizal-colonized host tree, (Quercus ilex), through the development of the brûlé and production of mature sporocarps. Area of study: This research was carried out province of Teruel, Aragon (central eastern Spain). Material and Methods: Soil samples from 6 plantations were collected beneath Q. ilex trees inoculated with T. melanosporum, of 3, 5, 7, 10, 14 and 20 years after out planting in truffle plantations. Soil DNA was extracted, PCR-amplified and sequenced to compare soil fungi present at different ages. Main results: As tree age increased, we observed an increased frequency of T. melanosporum (from 8% to 71% of sequenced colonies) and concomitant decrease in the combined frequency of Fusarium spp. and Phoma spp. (from 64% to 3%). Research highlights: There are important shifts in species richness and in functional groups in the soil fungal communities in maturing black truffle-oak woodland plantations. The observed inverse relationship between the frequency of soil endophytic and/or pathogenic fungi and that of the mycorrhizal mutualist T. melanosporum provides support to continue a deeper analysis of shifts in fungal communities and functional groups where there is a transition from agriculture fields to woodlands. (Author)

Goldspotted oak borer in California: Invasion history, biology, impact, management, and implications for Mediterranean forests worldwide

Science.gov (United States)

Tom Coleman; Steven Seybold

2016-01-01

In 2008, the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), was fi rst linked to elevated levels of oak mortality in southern California (CA), but it appears to have impacted oak woodlands and mixed conifer forests across all land ownerships in this region for nearly two decades. This unexpectedly damaging...

A review of fire and oak regeneration and overstory recruitment

Science.gov (United States)

Daniel C. Dey; Zhaofei Fan

2009-01-01

Fire has played a prominent role in the history of oak in eastern North America, and it is useful today for promoting oak regeneration where competition with other woody vegetation is a problem and for managing savannas and woodlands. We spent the last century extinguishing wildfire from forests for good reason, but now we must spend some time relearning how to use...

Transpiration Demand in Southern California Oak Woodlands: Making the Leap from Lab and Individual Tree to Watershed Scale

Science.gov (United States)

Weinberger, J. L.; Quinlan, P. T.; Martin, J.; Tartakovsky, D. M.

2013-12-01

Watershed scale estimates of evapotranspiration (ET) have proven difficult to quantify in areas of native vegetation with uncertain or unknown crop coefficients. In this study, we evaluate the water use in Quercus engelmanni and Quercus agrifolia, two species of oak native to Southern California. Thermal dissipation probes (TDPs) were installed at four locations within a 14,500 acre watershed, comprising 770 acres of Q. agrifolia woodland and 2440 acres of Q. engelmanni woodland. Installation duration ranged from 6 weeks to 14 months. The TDPs were calibrated to each species in the laboratory using limbs ranging from 2 to 5 inches in diameter. Dye was run through each limb at the end of the calibration test in order to establish a relationship between active sapwood area and limb diameter. ET measured in the field for each species was 0.15 to 0.3 times that of the reference evapotranspiration (ETo) derived from the Penman-Monteith equation, with the primary variability in the demand related to measured incident solar radiation. The total water demand for each species is estimated using the laboratory determined relationship between the active sapwood area and the diameter of the limb, and a survey of the tree diameter breast height (DBH) of each tree in the watershed. This study provides new insight into the actual water demand of two native tree species in Southern California and has serious implications for conservation plans, which are often developed using watershed models that apply ETo to all vegetation communities, regardless of actual water demand.

Pinyon-juniper woodlands

Science.gov (United States)

Gottfried, Gerald J.; Swetnam, Thomas W.; Allen, Craig D.; Betancourt, Julio L.; Chung-MacCoubrey, Alice L.; Finch, Deborah M.; Tainter, Joseph A.

1995-01-01

since the introduction of livestock and fire control. This relates to whether tree densities have been increasing or whether trees are invading grasslands and, to a lesser extent, drier ponderosa pine (Pinus ponderosa) forests. In areas where woodlands were heavily used by American Indians for fuelwood prior to European contact, the advance of pinyon and juniper could represent the slow recovery from intensive use (Samuels and Betancourt 1982). There are numerous questions regarding declines in watershed condition related to changes in pinyon-juniper tree stand densities and to the density and composition of understory vegetation. There are different opinions about proper management of woodland ecosystems. Should these lands be managed for a single resource, such as forage for livestock production, or managed for sustained production of multiple resource products and amenities? Depending on site and stand conditions, the woodlands can produce variable quantities of fuelwood, pinyon nuts, wildlife habitat, forage for livestock, and cover for watershed protection. Management must also consider increasing recreational demands, threatened and endangered species, and protection of archeological sites. Many pinyon-juniper woodland watersheds in New Mexico have unsatisfactory soil and watershed conditions (USDA Forest Service 1993); managers must develop restoration procedures that recognize the value of woodland ecosystems. The concerns, questions, and conflicts surrounding management of pinyon-juniper lands, as well as the ecological foundations of ecosystem management, require that all interested parties reevaluate attitudes toward the woodlands. Ecosystem management goals and concepts recognize diversity. Pinyonjuniper woodlands are diverse, and stand characteristics and site productivities vary. Management objectives and prescriptions must evaluate the potential of each site, and decisions must be based on sound scientific information. This information is often

Shifts in soil fungal communities in Tuber melanosporum plantations over a 20-year transition from agriculture fields to oak woodlands

Directory of Open Access Journals (Sweden)

Liu Bing

2016-04-01

Full Text Available Aim of study: To explore the diversity of soil fungi found in black truffle (Tuber melanosporum plantations following the introduction of the mycorrhizal-colonized host tree, (Quercus ilex, through the development of the brûlé and production of mature sporocarps.Area of study: This research was carried out province of Teruel, Aragon (central eastern Spain.Material and Methods: Soil samples from 6 plantations were collected beneath Q. ilex trees inoculated with T. melanosporum, of 3, 5, 7, 10, 14 and 20 years after out planting in truffle plantations. Soil DNA was extracted, PCR-amplified and sequenced to compare soil fungi present at different ages.Main results: As tree age increased, we observed an increased frequency of T. melanosporum (from 8% to 71% of sequenced colonies and concomitant decrease in the combined frequency of Fusarium spp. and Phoma spp. (from 64% to 3%.Research highlights: There are important shifts in species richness and in functional groups in the soil fungal communities in maturing black truffle-oak woodland plantations. The observed inverse relationship between the frequency of soil endophytic and/or pathogenic fungi and that of the mycorrhizal mutualist T. melanosporum provides support to continue a deeper analysis of shifts in fungal communities and functional groups where there is a transition from agriculture fields to woodlands.Abbreviations used: Ectomycorrhiza (ECM fungus; Vesicular arbuscular mycorrhiza (VAM; Operational taxonomic unit (OTU.

Migration of vascular plant species to a recent wood adjoining ancient woodland

Directory of Open Access Journals (Sweden)

Zbigniew Dzwonko

2014-01-01

Full Text Available Woodland communities can be restored by natural succession in sites adjoining ancient woodlands which can act as seed sources for trees, shrubs and woodland herbs. The influence of dominant tree species and the distance from an adjacent ancient oak-hornbeam woodland upon the floristic composition of species in a recent pine wood planted on dry rendzina soil were studied. It was found that, in spite of a 52-year long succession, the border between woods was sharp and the composition of species in the recent wood were significantly different than in the adjacent ancient woodland. Canonical correspondence analysis (CCA showed that the distance to the ancient woodland had a significant influence on species distributions in the recent wood. The numbers of species from the Querco-Fagetea class, vegetatively reproducing species and myrmecochores decreased with this distance, whereas the numbers of anemochores increased. The migration rate of many woodland species, calculated on occurrence of the farthest individuals was very slow, varying from 0.0 m year-1 to 0.38 m year-1. The restoration of the field layer vegetation in the studied pine wood was much slower than in recent deciduous woods on rich and moist soils where the migration rate of some species exceeded 1.50 m year-1. Recent woods adjacent to ancient woodlands can be more effectively colonised by woodland species only when they are dominated by broad-leaved trees with quickly decomposing litter, and the spatial continuity of these woods persists for a long period.

Where the woodland ends: How edges affect landscape structure and physiological responses of Quercus agrifolia

Science.gov (United States)

de Chant, Timothy Paul

Forests and woodlands are integral parts of ecosystems across the globe, but they are threatened by a variety of factors, including urbanization and introduced forest pathogens. These two forces are fundamentally altering ecosystems, both by removing forest cover and reshaping landscapes. Comprehending how these two processes have changed forest ecosystems is an important step toward understanding how the affected systems will function in the future. I investigated the range of edge effects that result from disturbance brought about by forest pathogens and urbanization in two coastal oak woodlands in Marin County, California. Oak woodlands are a dynamic part of California's landscape, reacting to changes in their biotic and abiotic environments across a range of spatial and temporal scales. Sudden Oak Death, caused by the introduced forest pathogen Phytophthora ramorum, has led to widespread mortality of many tree species in California's oak woodlands. I investigated how the remaining trees respond to such rapid changes in canopy structure (Chapter 2), and my results revealed a forest canopy quick to respond to the new openings. Urbanization, another disturbance regime, operates on a longer time scale. Immediately following urban development, forest edges are strikingly linear, but both forest processes and homeowner actions likely work in concert to disrupt the straight edge (Chapter 3). Forest edges grew more sinuous within 14 years of the initial disturbance, and continued to do so for the remainder of the study, another 21 years. Individual Quercus agrifolia trees also respond to urban edges decades after disturbance (Chapter 4), and their reaction is reflected in declining stable carbon isotope values (delta13C). This change suggests trees may have increased their stomatal conductance in response to greater water availability, reduced their photosynthetic rate as a result of stress, or some combination of both. Edges have far reaching and long lasting effects

Measurement of Leaf Mass and Leaf Area of Oaks In A Mediterranean-climate Region For Biogenic Emission Estimation

Science.gov (United States)

Karlik, J.

Given the key role played by biogenic volatile organic compounds (BVOC) in tro- pospheric chemistry and regional air quality, it is critical to generate accurate BVOC emission inventories. Because several oak species have high BVOC emission rates, and oak trees are often of large stature with corresponding large leaf masses, oaks may be the most important genus of woody plants for BVOC emissions modeling in the natural landscapes of Mediterranean-climate regions. In California, BVOC emis- sions from oaks may mix with anthropogenic emissions from urban areas, leading to elevated levels of ozone. Data for leaf mass and leaf area for a stand of native blue oaks (Quercus douglasii) were obtained through harvest and leaf removal from 14 trees lo- cated in the Sierra Nevada foothills of central California. Trees ranged in height from 4.2 to 9.9 m, with trunk diameters at breast height of 14 to 85 cm. Mean leaf mass density was 730 g m-2 for the trees and had an overall value of 310 g m-2 for the site. Consideration of the surrounding grassland devoid of trees resulted in a value of about 150 g m-2, less than half of reported values for eastern U.S. oak woodlands, but close to a reported value for oaks found in St. Quercio, Italy. The mean value for leaf area index (LAI) for the trees at this site was 4.4 m2 m-2. LAI for the site was 1.8 m2 m-2, but this value was appropriate for the oak grove only; including the surrounding open grassland resulted in an overall LAI value of 0.9 m2 m-2 or less. A volumetric method worked well for estimating the leaf mass of the oak trees. Among allometric relationships investigated, trunk circumference, mean crown radius, and crown projec- tion were well correlated with leaf mass. Estimated emission of isoprene (mg C m-2 h-1) for the site based these leaf mass data and experimentally determined emission rate was similar to that reported for a Mediterranean oak woodland in France.

Land Change in Eastern Mediterranean Wood-Pasture Landscapes

DEFF Research Database (Denmark)

Schaich, Harald; Kizos, Thanasis; Schneider, Stefan

2015-01-01

In Mediterranean Europe, wood-pasture landscapes with oak woodlands as emblematic ecosystems are undergoing rapid land-use change, which may threaten their legacy as hotspots of biodiversity, ecosystem services, and cultural heritage. The objective of this study was to quantify land cover changes...... and transitions as well as the dynamics of oak woodland patterns and densities over 50 years in two municipalities at the center and edges of Quercus macrolepis distribution in Northern Lesvos (Greece). We used aerial photographs from 1960 and WorldView-2 satellite images from 2010 to process land cover maps...... and metrics, and to calculate oak canopy cover with a point-grid sampling approach. Spatiotemporal dynamics of land cover change were generally high—especially between oak woodlands and grass- and shrub-lands, resulting in a more heterogeneous and fragmented landscape in 2010. Surprisingly, oak woodland area...

Factors affecting soil fauna feeding activity in a fragmented lowland temperate deciduous woodland.

Science.gov (United States)

Simpson, Jake E; Slade, Eleanor; Riutta, Terhi; Taylor, Michele E

2012-01-01

British temperate broadleaf woodlands have been widely fragmented since the advent of modern agriculture and development. As a result, a higher proportion of woodland area is now subject to edge effects which can alter the efficiency of ecosystem functions. These areas are particularly sensitive to drought. Decomposition of detritus and nutrient cycling are driven by soil microbe and fauna coactivity. The bait lamina assay was used to assess soil fauna trophic activity in the upper soil horizons at five sites in Wytham Woods, Oxfordshire: two edge, two intermediate and one core site. Faunal trophic activity was highest in the core of the woodland, and lowest at the edge, which was correlated with a decreasing soil moisture gradient. The efficiency of the assay was tested using four different bait flavours: standardised, ash (Fraxinus excelsior L.), oak (Quercus robur L.), and sycamore (Acer pseudoplatanus L.). The standardised bait proved the most efficient flavour in terms of feeding activity. This study suggests that decomposition and nutrient cycling may be compromised in many of the UK's small, fragmented woodlands in the event of drought or climate change.

Assessment of oak wilt threat to habitat of the golden-cheeked warbler, an endangered species, in central Texas

Science.gov (United States)

David N. Appel; Kim S. Camilli

2010-01-01

A major epidemic of oak wilt, caused by Ceratocystis fagacearum (Bretz) Hunt, has been killing trees in Central Texas for at least 40 years. This has created large and expanding canopy gaps in the vast, homogenous live oak woodlands (Quercus fusiformis Small) in the Edwards Plateau region of Texas. The changes in stand...

Factors affecting soil fauna feeding activity in a fragmented lowland temperate deciduous woodland.

Directory of Open Access Journals (Sweden)

Jake E Simpson

Full Text Available British temperate broadleaf woodlands have been widely fragmented since the advent of modern agriculture and development. As a result, a higher proportion of woodland area is now subject to edge effects which can alter the efficiency of ecosystem functions. These areas are particularly sensitive to drought. Decomposition of detritus and nutrient cycling are driven by soil microbe and fauna coactivity. The bait lamina assay was used to assess soil fauna trophic activity in the upper soil horizons at five sites in Wytham Woods, Oxfordshire: two edge, two intermediate and one core site. Faunal trophic activity was highest in the core of the woodland, and lowest at the edge, which was correlated with a decreasing soil moisture gradient. The efficiency of the assay was tested using four different bait flavours: standardised, ash (Fraxinus excelsior L., oak (Quercus robur L., and sycamore (Acer pseudoplatanus L.. The standardised bait proved the most efficient flavour in terms of feeding activity. This study suggests that decomposition and nutrient cycling may be compromised in many of the UK's small, fragmented woodlands in the event of drought or climate change.

Restoring silvopastures with oak saplings: Effects of mulch and diameter class on survival, growth, and annual leaf-nutrient patterns

Science.gov (United States)

M. N. Jimenez; J. R. Pinto; M. A. Ripoll; A. Sanchez-Miranda; F. B. Navarro

2014-01-01

In Southwestern Spain, multifunctional silvopastoral systems consisting of pastureland and open oak woodlands are known as Dehesas. These, and other similar systems of the Mediterranean basin, are currently threatened by increasing intensive land use. As a consequence, oak regeneration is declining and is in need of adequate management and active restoration....

Framing conservation on private lands: conserving oak in Oregon's Willamette Valley

Science.gov (United States)

A. Paige Fischer; John C. Bliss

2009-01-01

Conserving threatened habitats on private lands requires policies that advance the interests of landowners and natural resource professionals alike. Through qualitative analysis of individual and focus-group interviews, we compared how family forest owners and natural resource professionals frame conservation of threatened habitat: the oak woodlands and savanna in...

Effects of tornado damage, prescribed fire, and salvage logging on natural oak (Quercus spp.) regeneration in a xeric southern USA Coastal Plain oak/pine forest

Science.gov (United States)

Jeffery B. Cannon; J. Stephen Brewer

2013-01-01

Due in large part to fire exclusion, many oak-dominated (Quercus spp.) forests, woodlands, and savannas throughout eastern North America are being replaced by less diverse forest ecosystems. In the interior coastal plain of the southern United States, these forests are dominated in the mid- and understory by mesophytic species such as Acer...

Effects of Spatial Distribution of Trees on Density Estimation by Nearest Individual Sampling Method: Case Studies in Zagros Wild Pistachio Woodlands and Simulated Stands

Directory of Open Access Journals (Sweden)

Y. Erfanifard

2014-06-01

Full Text Available Distance methods and their estimators of density may have biased measurements unless the studied stand of trees has a random spatial pattern. This study aimed at assessing the effect of spatial arrangement of wild pistachio trees on the results of density estimation by using the nearest individual sampling method in Zagros woodlands, Iran, and applying a correction factor based on the spatial pattern of trees. A 45 ha clumped stand of wild pistachio trees was selected in Zagros woodlands and two random and dispersed stands with similar density and area were simulated. Distances from the nearest individual and neighbour at 40 sample points in a 100 × 100 m grid were measured in the three stands. The results showed that the nearest individual method with Batcheler estimator could not calculate density correctly in all stands. However, applying the correction factor based on the spatial pattern of the trees, density was measured with no significant difference in terms of the real density of the stands. This study showed that considering the spatial arrangement of trees can improve the results of the nearest individual method with Batcheler estimator in density measurement.

Evapotranspiration from a Mediterranean evergreen oak savannah: The role of trees and pasture

Science.gov (United States)

Paço, Teresa A.; David, Teresa S.; Henriques, Manuel O.; Pereira, João S.; Valente, Fernanda; Banza, João; Pereira, Fernando L.; Pinto, Clara; David, Jorge S.

2009-05-01

SummaryMediterranean evergreen oak woodlands of southern Portugal ( montados) are savannah-type ecosystems with a widely sparse tree cover, over extensive grassland. Therefore, ecosystem water fluxes derive from two quite differentiated sources: the trees and the pasture. Partitioning of fluxes according to these different sources is necessary to quantify overall ecosystem water losses as well as to improve knowledge on its functional behaviour. In southern Iberia, these woodlands are subjected to recurrent droughts. Therefore, reaction/resilience to water stress becomes an essential feature of vegetation on these ecosystems. Long-term tree transpiration was recorded for 6 years from a sample of holm oak ( Quercus ilex ssp. rotundifolia) trees, using the Granier sap flow method. Ecosystem transpiration was measured by the eddy covariance technique for an 11-month period (February to December 2005), partly coincident with a drought year. Pasture transpiration was estimated as the difference between ecosystem (eddy covariance) and tree (sap flow) transpiration. Pasture transpiration stopped during the summer, when the surface soil dried up. In the other seasons, pasture transpiration showed a strong dependence on rainfall occurrence and on top soil water. Conversely, trees were able to maintain transpiration throughout the summer due to the deep root access to groundwater. Q. ilex trees showed a high resilience to both seasonal and annual drought. Tree transpiration represented more than half of ecosystem transpiration, in spite of the low tree density (30 trees ha -1) and crown cover fraction (21%). Tree evapotranspiration was dominated by transpiration (76%), and interception loss represented only 24% of overall tree evaporation.

Changes in Gambel oak densities in southwestern ponderosa pine forests since Euro-American settlement

Science.gov (United States)

Scott R. Abella; Peter Z. Fulé

2008-01-01

Densities of small-diameter ponderosa pine (Pinus ponderosa) trees have increased in southwestern ponderosa pine forests during a period of fire exclusion since Euro-American settlement in the late 1800s. However, less well known are potential changes in Gambel oak (Quercus gambelii) densities during this period in these forests....

Hydrology of southwestern encinal oak ecosystems: A review and more

Science.gov (United States)

Gerald J. Gottfried; Peter F. Ffolliott; Daniel G. Neary

2007-01-01

Information about the hydrology of oak ecosystems of the southwestern United States and northern Mexico is lacking (Lopes and Ffolliott 1992, Baker et al. 1995) even though the woodlands and savannas cover more than 31,000 square miles. These ecosystems generally are found between 4,000 and 7,300 feet in elevation. Precipitation occurs in the winter and summer and...

Changes to oak woodland stand structure and ground flora composition caused by thinning and burning

Science.gov (United States)

Kinkead, Carter O.; Kabrick, John M.; Stambaugh, Michael C.; Grabner, Keith W.

2013-01-01

Our objective was to quantify the cumulative effects of prescribed burning and thinning on forest stocking and species composition at a woodland restoration experiment site in the Ozark Highlands of Missouri. Our study used four treatments (burn, harvest, harvest and burn, control) on three slope position and aspect combinations (south, north, ridge) replicated in three complete blocks. Harvested stands were thinned from below to 40 percent residual stocking. Two prescribed fires were applied to both burn and harvest-burn treatment units in a 5-year period. Results reflect changes that have taken place over a 6-year period, from pretreatment conditions to 1 year after the last fire. In this period, there was a 10-percent reduction in the stocking in burned stands compared to control and a 6-percent reduction in harvested and burned stands compared to harvested stands. Compared to the control, percentage ground cover of woodland indicators was seven times greater in burned stands, six times greater in harvested stands, and 22 percent greater in harvested and burned stands. Th ere was no significant (P > 0.05) interaction between aspect and treatment on stocking or ground flora cover. Th is study indicated that silvicultural treatments do achieve various goals that are common to managers who aim to restore woodland communities.

Population ecology and conservation of beetles and pseudoscorpions living in hollow oaks in Sweden

OpenAIRE

Ranius, T.

2002-01-01

This paper aims at giving a summary of recent research on the habitat requirements and population structure of beetles and pseudoscorpions living in old, hollow oaks in Sweden. An inventory of old oaks in pasture woodlands revealed that the species richness of beetles is higher at sites that are originally open and are still grazed. The trees in these plots are preferred for two reasons: they are more sun-exposed and have a larger trunk diameter. Many species are harmed by forest regrowth and...

Influence of overstory density on ecophysiology of red oak (Quercus rubra) and sugar maple (Acer saccharum) seedlings in central Ontario shelterwoods

Science.gov (United States)

William C. Parker; Daniel C. Dey

2008-01-01

A field experiment was established in a secondgrowth hardwood forest dominated by red oak (Quercus rubra L.) to examine the effects of shelterwood overstory density on leaf gas exchange and seedling water status of planted red oak, naturally regenerated red oak and sugar maple (Acer saccharum Marsh.) seedlings during the first...

The influence of vegetation on bird distribution in dry forests and oak woodlands of western Mexico

Directory of Open Access Journals (Sweden)

Pablo Corcuera

2006-06-01

Full Text Available The bird species distribution along a dry forest-oak woodland vegetation gradient was studied in autumn and spring in two consecutive years. Intra-seasonal comparisons showed that bird species had similar distributions in each of the two years. Inter-seasonal changes were mainly due to compositional differences even though resident species generally used similar habitats in both seasons. Ordination analyses, based on the first year bird species abundances, showed a clearly segregated distribution between forest and woodland birds. Within these two vegetation types, the distribution tended to be more individualistic. Nevertheless further habitats could be identified according to groups of birds having similar distributions. These habitats did not correspond to the plant associations which resulted from a previous classification of the vegetation. Observations of the plant use by the birds during the study period showed that, in most cases, the plant variables associated with ordination analyses are unlikely to be very important for the bird species life cycles. Rev. Biol. Trop. 54(2: 657-672. Epub 2005 Jun 01.Se estudió la distribución de especies de aves a lo largo de un gradiente de vegetación bosque seco - bosque de encino en el otoño y primavera de dos años consecutivos. Las comparaciones intra-estacionales mostraron distribuciones similares de las especies de aves en ambos años. Los cambios inter-estacionales se debieron principalmente a diferencias en la composición, aunque las especies residentes normalmente usan hábitats similares en ambas estaciones. Los análisis de ordenación, basados en las abundancias de las aves en el primer año de muestreo, mostraron una distribución claramente segregada entre aves del bosque seco y del bosque de encino. Aunque la distribución de las especies fue más azarosa dentro de cada tipo de vegetación, se pudieron identificar ciertos hábitats en base a grupos de aves con distribuciones

Restoration of Black Oak (Quercus velutina) Sand Barrens via Three Different Habitat Management Approaches

Science.gov (United States)

Kriska, David John

Disturbance regimes, i.e. frequent fires, historically maintained oak barrens until European settlement patterns, and eventually, Smoky the Bear and the fire suppression campaign of the U.S. Forest Service snuffed out the periodic flames. In the absence of a disturbance regime, ground layer floral composition at many historical oak sand barrens will change predominantly because of a buildup of leaf litter and shading of the soils. Termed mesophication, this process of ecological succession will drive Black Oak Sand Barrens to an alternate steady state. A survey conducted on Singer Lake Bog in Green, Ohio, demonstrated that succession shifted the community to red maple-black cherry woodlands more typical of a dry southern forest. In an attempt to revive disturbance, three restoration techniques were applied at ten degraded northeast Ohio oak barrens to contrast their effectiveness in restoring black oak sand barren flora. The three restoration treatments were select canopy tree reduction favoring 5% to 30% tree canopy cover, forest floor leaf litter removal, and prescribed fire. Vegetation responses to manipulations were monitored prior to and following treatment applications, and were compared against both baseline data from before-treatment surveys and paired control sites adjacent treated areas. Imposing disturbance successfully increased species diversity and abundance above that found across Singer Lake Bog compared to sampling made prior to and adjacent to treated areas. Select canopy tree removal exhibited the largest floral responses from targeted barrens species, i.e. graminoids. A forest floor invertebrate family (Carabidea: Coleoptera) was measured for species richness and abundance pre and post treatment, where a noticeable shift occurred away from woodland obligate ground beetles toward open grassland species. Replicating oak barren structure, prior to replicating disturbance processes, is the first step in the ecological restoration of these systems.

Blue oak plant communities of southern San Luis Obispo and northern Santa Barbara Counties, California

Science.gov (United States)

Mark I. Borchert; Nancy D. Cunha; Patricia C. Krosse; Marcee L. Lawrence

1993-01-01

An ecological classification system has been developed for the Pacific Southwest Region of the Forest Service. As part of that classification effort, blue oak (Quercus douglasii) woodlands and forests of southern San Luis Obispo and northern Santa Barbara Counties in Los Padres National Forest were classified into I3 plant communities using...

Habitat fragmentation impacts mobility in a common and widespread woodland butterfly: do sexes respond differently?

Directory of Open Access Journals (Sweden)

Bergerot Benjamin

2012-04-01

Full Text Available Abstract Background Theory predicts a nonlinear response of dispersal evolution to habitat fragmentation. First, dispersal will be favoured in line with both decreasing area of habitat patches and increasing inter-patch distances. Next, once these inter-patch distances exceed a critical threshold, dispersal will be counter-selected, unless essential resources no longer co-occur in compact patches but are differently scattered; colonization of empty habitat patches or rescue of declining populations are then increasingly overruled by dispersal costs like mortality risks and loss of time and energy. However, to date, most empirical studies mainly document an increase of dispersal associated with habitat fragmentation. We analyzed dispersal kernels for males and females of the common, widespread woodland butterfly Pararge aegeria in highly fragmented landscape, and for males in landscapes that differed in their degree of habitat fragmentation. Results The male and female probabilities of moving were considerably lower in the highly fragmented landscapes compared to the male probability of moving in fragmented agricultural and deciduous oak woodland landscapes. We also investigated whether, and to what extent, daily dispersal distance in the highly fragmented landscape was influenced by a set of landscape variables for both males and females, including distance to the nearest woodland, area of the nearest woodland, patch area and abundance of individuals in the patch. We found that daily movement distance decreased with increasing distance to the nearest woodland in both males and females. Daily distances flown by males were related to the area of the woodland capture site, whereas no such effect was observed for females. Conclusion Overall, mobility was strongly reduced in the highly fragmented landscape, and varied considerably among landscapes with different spatial resource distributions. We interpret the results relative to different cost

Effects of urban density on carbon dioxide exchanges: Observations of dense urban, suburban and woodland areas of southern England.

Science.gov (United States)

Ward, H C; Kotthaus, S; Grimmond, C S B; Bjorkegren, A; Wilkinson, M; Morrison, W T J; Evans, J G; Morison, J I L; Iamarino, M

2015-03-01

Anthropogenic and biogenic controls on the surface-atmosphere exchange of CO2 are explored for three different environments. Similarities are seen between suburban and woodland sites during summer, when photosynthesis and respiration determine the diurnal pattern of the CO2 flux. In winter, emissions from human activities dominate urban and suburban fluxes; building emissions increase during cold weather, while traffic is a major component of CO2 emissions all year round. Observed CO2 fluxes reflect diurnal traffic patterns (busy throughout the day (urban); rush-hour peaks (suburban)) and vary between working days and non-working days, except at the woodland site. Suburban vegetation offsets some anthropogenic emissions, but 24-h CO2 fluxes are usually positive even during summer. Observations are compared to estimated emissions from simple models and inventories. Annual CO2 exchanges are significantly different between sites, demonstrating the impacts of increasing urban density (and decreasing vegetation fraction) on the CO2 flux to the atmosphere. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Energy from the woodlands

Science.gov (United States)

Jerry Payne

2008-01-01

(Please note, this is an abstract only) The woodlands offer a significant opportunity for conversion of biomass to energy projects. With the vast acreage in the Southwest in the woodland type, and with the significant soil loss problems prevalent in this area, there is a dire need to treat the woodlands. Since there are limited opportunities for marketable products,...

Overstory density affects field performance of underplanted red oak (Quercus rubra L.) in Ontario

Science.gov (United States)

Daniel C. Dey; William C. Parker

1997-01-01

Red oak seedlings were underplanted in a closed-canopy mature northern hardwood stand and an adjacent shelterwood in central Ontario. Overstory density effects on seedling survival and growth were assessed 2 yr after planting. After 2 yr, seedling survival was 90% in the uncut stand and over 99% in the shelterwood. Seedlings in the uncut stand experienced negligible or...

Water-use strategies in two co-occurring Mediterranean evergreen oaks: surviving the summer drought.

Science.gov (United States)

David, T S; Henriques, M O; Kurz-Besson, C; Nunes, J; Valente, F; Vaz, M; Pereira, J S; Siegwolf, R; Chaves, M M; Gazarini, L C; David, J S

2007-06-01

In the Mediterranean evergreen oak woodlands of southern Portugal, the main tree species are Quercus ilex ssp. rotundifolia Lam. (holm oak) and Quercus suber L. (cork oak). We studied a savannah-type woodland where these species coexist, with the aim of better understanding the mechanisms of tree adaptation to seasonal drought. In both species, seasonal variations in transpiration and predawn leaf water potential showed a maximum in spring followed by a decline through the rainless summer and a recovery with autumn rainfall. Although the observed decrease in predawn leaf water potential in summer indicates soil water depletion, trees maintained transpiration rates above 0.7 mm day(-1) during the summer drought. By that time, more than 70% of the transpired water was being taken from groundwater sources. The daily fluctuations in soil water content suggest that some root uptake of groundwater was mediated through the upper soil layers by hydraulic lift. During the dry season, Q. ilex maintained higher predawn leaf water potentials, canopy conductances and transpiration rates than Q. suber. The higher water status of Q. ilex was likely associated with their deeper root systems compared with Q. suber. Whole-tree hydraulic conductance and minimum midday leaf water potential were lower in Q. ilex, indicating that Q. ilex was more tolerant to drought than Q. suber. Overall, Q. ilex seemed to have more effective drought avoidance and drought tolerance mechanisms than Q. suber.

Assessment of bird populations in a high quality savanna/woodland: a banding approach

Science.gov (United States)

Wilmore, Sandra L.; Glowacki, Gary A.; Grundel, Ralph

2005-01-01

Between 1999 and 2004, Save the Dunes Conservation Fund's Miller Woods Bird Banding Program monitored migrating and breeding bird populations within a high quality black oak, dry-mesic sand savanna/woodland with ridge and swale topography. The objectives of this program were to collect consistent and reliable demographic and abundance data on the bird populations, to investigate long-term population trends, and to contribute to improved land management decisions at regional and national scales. The technique employed involved capturing birds in mist nets that were deployed for set periods of time at 17 net sites in two banding areas in Miller Woods.

Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

Directory of Open Access Journals (Sweden)

Erica N Spotswood

Full Text Available Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species, temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

Science.gov (United States)

Spotswood, Erica N; Bartolome, James W; Allen-Diaz, Barbara

2015-01-01

Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species), temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

Influence of tree cover on herbaceous layer development and carbon and water fluxes in a Portuguese cork-oak woodland

Science.gov (United States)

Dubbert, Maren; Mosena, Alexander; Piayda, Arndt; Cuntz, Matthias; Correia, Alexandra Cristina; Pereira, Joao Santos; Werner, Christiane

2014-08-01

Facilitation and competition between different vegetation layers may have a large impact on small-scale vegetation development. We propose that this should not only influence overall herbaceous layer yield but also species distribution and understory longevity, and hence the ecosystems carbon uptake capacity especially during spring. We analyzed the effects of trees on microclimate and soil properties (water and nitrate content) as well as the development of an herbaceous community layer regarding species composition, aboveground biomass and net water and carbon fluxes in a cork-oak woodland in Portugal, between April and November 2011. The presence of trees caused a significant reduction in photosynthetic active radiation of 35 mol m-2 d-1 and in soil temperature of 5 °C from April to October. At the same time differences in species composition between experimental plots located in open areas and directly below trees could be observed: species composition and abundance of functional groups became increasingly different between locations from mid April onwards. During late spring drought adapted native forbs had significantly higher cover and biomass in the open area while cover and biomass of grasses and nitrogen fixing forbs was highest under the trees. Further, evapotranspiration and net carbon exchange decreased significantly stronger under the tree crowns compared to the open during late spring and the die back of herbaceous plants occurred earlier and faster under trees. This was most likely caused by interspecific competition for water between trees and herbaceous plants, despite the more favorable microclimate conditions under the trees during the onset of summer drought.

Management effect on bird and arthropod interaction in suburban woodlands

Science.gov (United States)

2011-01-01

Background Experiments from a range of ecosystems have shown that insectivorous birds are important in controlling the populations of their invertebrate prey. Here, we report on a large field experiment testing the hypothesis that management for enhancing recreational values in suburban woodlands affects the intensity of bird predation on canopy-living arthropods. Bird exclosures were used in two types of management (understory clearance and dense understory) at two foraging heights in oak Quercus robur canopies and the experiment was replicated at two sites. Results The biomass and abundance of arthropods were high on net-enclosed branches but strongly reduced on control branches in both types of management. In woods with dense understory, the effect of bird predation on arthropod abundance was about twice as high as in woods with understory clearance. The effect of bird predation on arthropod biomass was not significantly affected by management. Conclusions Our data provide experimental evidence to support the idea that bird predation on arthropods can be affected by forest management. We suggest that the mechanism is twofold: reduction of bird abundance and shift of foraging behaviour. In urban woodlands, there may be a management trade-off between enhancing recreational values and promoting bird predation rates on arthropods. PMID:21362174

Woodlands Grazing Issues in Mediterranean Basin

Science.gov (United States)

Campos, P.

2009-04-01

In Mediterranean basin, woodlands grazing still continue to be important commercial owners' benefits. These owners manage woodlands vegetations as if they were not at risk of degradation and declining. Frequently, no temporally grazing set-aside is taken into account to avoid overgrazing of annual and perennial vegetations. Although less common, in the northern shore of Mediterranean basin undergrazing might increase the frequency and the number of catastrophic forest fires. This under/over grazing regime occurs in the Mediterranean basin woodlands with contrasted differences on land property rights, local economies and government livestock policy incentives. Spain and Tunisia are examples of these Mediterranean livestock contrasts. Most of Spanish Mediterranean woodlands and livestock herds are large private ownerships and owners could maintain their lands and livestock herds properties on the basis of moderate cash-income compensation against land revaluation and exclusive amenity self-consumption. The later is less tangible benefit and it could include family land legacy, nature enjoyment, country stile of life development, social status and so on. In public woodlands, social and environmental goals -as they are cultural heritage, biodiversity loss mitigation, soil conservation and employment- could maintain market unprofitable woodlands operations. Last three decades Spanish Mediterranean woodlands owners have increased the livestock herds incentivized by government subsidies. As result, grazing rent is pending on the level of European Union and Spanish government livestock subsidies. In this context, Spanish Mediterranean woodlands maintain a high extensive livestock stoking population, which economy could be called fragile and environmentally unsustainable because forest degradation and over/under grazing practices. Tunisian Mediterranean woodlands are state properties and livestock grazing is practice as a free private regimen. Livestock herds are small herd

Assessing mechanical mastication and thinning-piling-burning treatments on the pinyon-juniper woodlands of southwestern Colorado

Science.gov (United States)

Gerald Gottfried; Steve Overby

2011-01-01

New knowledge of fire regimes in the pinyon-juniper woodlands of the interior western United States has altered management views. Once known as being at low wildfire risk, these woodlands are now at a higher risk for severe wildfires because of high tree densities exacerbated by ongoing drought and region-wide bark beetle (Ips confusus) infestation. To help reduce...

Pinyon/juniper woodlands [Chapter 4

Science.gov (United States)

Robin J. Tausch; Sharon Hood

2007-01-01

Pinyon-juniper woodlands occur in 10 states and cover large areas in many of them. These woodlands can be dominated by several species of pinyon pine (Pinus spp. L.) and juniper (Juniperus spp. L.) (Lanner 1975; Mitchell and Roberts 1999; West 1999a). A considerable amount of information is available on the expansion of the woodlands that has occurred over large parts...

Long-term variability and environmental control of the carbon cycle in an oak-dominated temperate forest

Science.gov (United States)

Jing Xie; Jiquan Chen; Ge Sun; Housen Chu; Asko Noormets; Zutao Ouyang; Ranjeet John; Shiqiang Wan; Wenbin Guan

2014-01-01

Our understanding of the long-term carbon (C) cycle of temperate deciduous forests and its sensitivity to climate variability is limited due to the large temporal dynamics of C fluxes. The goal of the study was to quantify the effects of environmental variables on the C balance in a 70-year-old mixed-oak woodland forest over a 7-year period in northwest Ohio, USA. The...

Effects of urban density on carbon dioxide exchanges: Observations of dense urban, suburban and woodland areas of southern England

International Nuclear Information System (INIS)

Ward, H.C.; Kotthaus, S.; Grimmond, C.S.B.; Bjorkegren, A.; Wilkinson, M.; Morrison, W.T.J.; Evans, J.G.; Morison, J.I.L.; Iamarino, M.

2015-01-01

Anthropogenic and biogenic controls on the surface–atmosphere exchange of CO 2 are explored for three different environments. Similarities are seen between suburban and woodland sites during summer, when photosynthesis and respiration determine the diurnal pattern of the CO 2 flux. In winter, emissions from human activities dominate urban and suburban fluxes; building emissions increase during cold weather, while traffic is a major component of CO 2 emissions all year round. Observed CO 2 fluxes reflect diurnal traffic patterns (busy throughout the day (urban); rush-hour peaks (suburban)) and vary between working days and non-working days, except at the woodland site. Suburban vegetation offsets some anthropogenic emissions, but 24-h CO 2 fluxes are usually positive even during summer. Observations are compared to estimated emissions from simple models and inventories. Annual CO 2 exchanges are significantly different between sites, demonstrating the impacts of increasing urban density (and decreasing vegetation fraction) on the CO 2 flux to the atmosphere. - Highlights: • Multi-seasonal comparison of contemporaneous CO 2 fluxes over contrasting land cover. • Signatures of anthropogenic and biogenic processes explored at various timescales. • Observations reveal relative magnitude of anthropogenic emissions. • CO 2 fluxes related to surface controls, strongly dependent on land cover. - Direct measurements of CO 2 fluxes reveal the impact of urbanisation and human behavioural patterns on the atmosphere at sub-daily to inter-annual time scales

Fuel-wood from undermanaged woodland

Energy Technology Data Exchange (ETDEWEB)

Landen, R A

1995-11-22

This report examines the potential for the utilisation of currently undermanaged woodland for supply of wood fuel. The potential markets for wood fuel are identified, along with their requirements in terms of fuel specification. Woodland resources currently receiving little or no management are identified, concentrating on broadleaves in lowland Britain. The nature of these resources is discussed, and opportunities/constraints for their management reviewed. Machinery suitable for these woodland areas is discussed, and the application of this equipment into practical systems is examined in some detail. These themes are developed in two case studies, resulting in a discussion of findings and a range of conclusions. It is believed that potential exists to extract chipped wood fuel form existing unmanaged woodland areas from Pound 25/gt upwards, including standing value and contractor profit. (Author)

Supply of wood fuel from small-scale woodlands for small-scale heating

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

This report summarises the findings of a study aimed at stimulating a market for wood fuels. A desk study of harvesting in existing small woodland was conducted, and thirteen case studies covering early broadleaved thinnings, mixed broadleaved coppice, and crownwood, scrub and residues were examined to obtain information on woodland types, wood fuel supply, and combustion equipment. Details are given of the measurement of moisture content of woodchips and stacked roundwood, wood volume and green density, harvesting options, crop and site variables, and production and costs of wood fuels. Usage of wood fuels, and the drying of small roundwood was considered. (UK)

Developing a Carbon Monitoring System For Pinyon-juniper Forests and Woodlands

Science.gov (United States)

Falkowski, M. J.; Hudak, A. T.; Fekety, P.; Filippelli, S.

2017-12-01

Pinyon-juniper (PJ) forests and woodlands are the third largest vegetation type in the United States. They cover over 40 million hectares across the western US, representing 40% of the total forest and woodland area in the Intermountain West. Although the density of carbon stored in these ecosystems is relatively low compared to other forest types, the vast area of short stature forests and woodlands (both nationally and globally) make them critical components of regional, national, and global carbon budgets. The overarching goal of this research is to prototype a carbon monitoring, reporting, and verification (MRV) system for characterizing total aboveground biomass stocks and flux across the PJ vegetation gradient in the western United States. We achieve this by combining in situ forest measurements and novel allometric equations with tree measurements derived from high resolution airborne imagery to map aboveground biomass across 500,000 km2 in the Western US. These high-resolution maps of aboveground biomass are then leveraged as training data to predict biomass flux through time from Landsat time-series data. The results from this research highlight the potential in mapping biomass stocks and flux in open forests and woodlands, and could be easily adopted into an MRV framework.

Eastern wood-pewee (Contopus virens) breeding demography across a gradient of savanna, woodland, and forest in the Missouri Ozarks

Science.gov (United States)

Sarah W. Kendrick; Frank R. Thompson; Jennifer L. Reidy

2013-01-01

Better knowledge of bird response to savanna and woodland restoration is needed to inform management of these communities. We related temporal and habitat variables to breeding demography and densities of the Eastern Wood-Pewee (Contopus virens) across a gradient of savanna, woodland, and forest. We determined nest success, clutch size, young fledged...

Impact of Canopy Openness on Spider Communities: Implications for Conservation Management of Formerly Coppiced Oak Forests.

Directory of Open Access Journals (Sweden)

Ondřej Košulič

Full Text Available Traditional woodland management created a mosaic of differently aged patches providing favorable conditions for a variety of arthropods. After abandonment of historical ownership patterns and traditional management and the deliberate transformation to high forest after World War II, large forest areas became darker and more homogeneous. This had significant negative consequences for biodiversity. An important question is whether even small-scale habitat structures maintained by different levels of canopy openness in abandoned coppiced forest may constitute conditions suitable for forest as well as open habitat specialists. We investigated the effect of canopy openness in former traditionally coppiced woodlands on the species richness, functional diversity, activity density, conservation value, and degree of rareness of epigeic spiders. In each of the eight studied locations, 60-m-long transect was established consisting of five pitfall traps placed at regular 15 m intervals along the gradient. Spiders were collected from May to July 2012. We recorded 90 spider species, including high proportions of xeric specialists (40% and red-listed threatened species (26%. The peaks of conservation indicators, as well as spider community abundance, were shifted toward more open canopies. On the other hand, functional diversity peaked at more closed canopies followed by a rapid decrease with increasing canopy openness. Species richness was highest in the middle of the canopy openness gradient, suggesting an ecotone effect. Ordinations revealed that species of conservation concern tended to be associated with sparse and partly opened canopy. The results show that the various components of biodiversity peaked at different levels of canopy openness. Therefore, the restoration and suitable forest management of such conditions will retain important diversification of habitats in formerly coppiced oak forest stands. We indicate that permanent presence of small

Factors influencing woodlands of southwestern North Dakota

Science.gov (United States)

Michele M. Girard; Harold Goetz; Ardell J. Bjugstad

1987-01-01

Literature pertaining to woodlands of southwestern North Dakota is reviewed. Woodland species composition and distribution, and factors influencing woodland ecosystems such as climate, logging, fire, and grazing are described. Potential management and improvement techniques using vegetation and livestock manipulation have been suggested.

Carbon stocks, greenhouse gas emissions and water balance of Sudanese savannah woodlands in relation to climate change

Energy Technology Data Exchange (ETDEWEB)

Alam, S. A.

2013-06-01

Understanding the carbon (C) sequestration potential of drylands requires knowledge of the stocks of C in soils and biomass and on the factors affecting them. The overall aim of the study was to determine and evaluate the variation in the C stocks and water balance of Acacia savannah woodlands across the dryland (arid and semi-arid) region (10-16 deg N; 21-36 deg E) of the former Sudan (now mainly in the Republic of the Sudan) and how they are related to climatic factors and may be affected by climate change. The role played by small but numerous brick making industries on woodland deforestation in the region and greenhouse gas production was also investigated. The study region is often referred to as the gum belt because it is the world's major source of gum Arabic, which is harvested from Acacia trees. The soils in the centre and west of the region are mainly Arenosols (sandy soils) and those in the eastern part are mainly Vertisols (clay soils). The soils are C poor and often in a degraded state. This dissertation consists of a summary section and four articles (Study I, II, III and IV). Study I focuses on fuelwood consumption by the brick making industries (BMIs) and associated deforestation and greenhouse gas (GHG) emissions. In Study II the C densities (g C m-2) of the woodland tree biomass and soil (1 m) for 39 map sheets covering the study region were determined from national forest inventory data and global soil databases and the dependence on mean annual precipitation (MAP) and mean annual temperature (MAT) determined. The water balance of savannah woodlands for the same 39 map sheets was modelled in Study III and the variation in water balance components across the region evaluated. The potential impacts of climate change on woodland biomass C density and water-use (actual evapotranspiration, AET) was analysed for eight of the map sheets in Study IV. Sudanese BMIs consume a considerable amount of fuelwood that mainly comes from unsustainably managed

Tree-rings mirror management legacy: dramatic response of standard oaks to past coppicing in Central Europe.

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Jan Altman

Full Text Available BACKGROUND: Coppicing was one of the most important forest management systems in Europe documented in prehistory as well as in the Middle Ages. However, coppicing was gradually abandoned by the mid-20(th century, which has altered the ecosystem structure, diversity and function of coppice woods. METHODOLOGY/PRINCIPAL FINDINGS: Our aim was to disentangle factors shaping the historical growth dynamics of oak standards (i.e. mature trees growing through several coppice cycles in a former coppice-with-standards in Central Europe. Specifically, we tried to detect historical coppicing events from tree-rings of oak standards, to link coppicing events with the recruitment of mature oaks, and to determine the effects of neighbouring trees on the stem increment of oak standards. Large peaks in radial growth found for the periods 1895-1899 and 1935-1939 matched with historical records of coppice harvests. After coppicing, the number of newly recruited oak standards markedly grew in comparison with the preceding or following periods. The last significant recruitment of oak standards was after the 1930s following the last regular coppicing event. The diameter increment of oak standards from 1953 to 2003 was negatively correlated with competition indices, suggesting that neighbouring trees (mainly resprouting coppiced Tilia platyphyllos partly suppressed the growth of oak standards. Our results showed that improved light conditions following historical coppicing events caused significant increase in pulses of radial growth and most probably maintained oak recruitment. CONCLUSIONS/SIGNIFICANCE: Our historical perspective carries important implications for oak management in Central Europe and elsewhere. Relatively intense cutting creating open canopy woodlands, either as in the coppicing system or in the form of selective cutting, is needed to achieve significant radial growth in mature oaks. It is also critical for the successful regeneration and long

Net ecosystem carbon exchange in three contrasting Mediterranean ecosystems – the effect of drought

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T. S. David

2007-09-01

Full Text Available Droughts reduce gross primary production (GPP and ecosystem respiration (Reco, contributing to most of the inter-annual variability in terrestrial carbon sequestration. In seasonally dry climates (Mediterranean, droughts result from reductions in annual rainfall and changes in rain seasonality. We compared carbon fluxes measured by the eddy covariance technique in three contrasting ecosystems in southern Portugal: an evergreen oak woodland (savannah-like with ca.~21% tree crown cover, a grassland dominated by herbaceous annuals and a coppiced short-rotation eucalyptus plantation. During the experimental period (2003–2006 the eucalyptus plantation was always the strongest sink for carbon: net ecosystem exchange rate (NEE between −861 and −399 g C m−2 year−1. The oak woodland and the grassland were much weaker sinks for carbon: NEE varied in the oak woodland between −140 and −28 g C m−2 year−1 and in the grassland between −190 and +49 g C m−2 year−1. The eucalyptus stand had higher GPP and a lower proportion of GPP spent in respiration than the other systems. The higher GPP resulted from high leaf area duration (LAD, as a surrogate for the photosynthetic photon flux density absorbed by the canopy. The eucalyptus had also higher rain use efficiency (GPP per unit of rain volume and light use efficiency (the daily GPP per unit incident photosynthetic photon flux density than the other two ecosystems. The effects of a severe drought could be evaluated during the hydrological-year (i.e., from October to September of 2004–2005. Between October 2004 and June 2005 the precipitation was only 40% of the long-term average. In 2004–2005 all ecosystems had GPP lower than in wetter years and carbon sequestration was strongly restricted (less negative NEE. The grassland was a net source of carbon dioxide (+49 g C m−2 year−1. In the oak woodland a large proportion of GPP resulted from carbon assimilated by its annual vegetation

Lack of nest site limitation in a cavity-nesting bird community

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Jeffry R. Waters; Barry R. Noon; Jared Verner

1990-01-01

We examined the relationship between nest site availability and density of secondary cavitynesting birds by blocking cavities in an oak-pine (Quercus spp.-Pinus sp. ) woodland. In 1986 and 1987we blocked 67 and 106 cavities, respectively, on a 37-ha plot. The combined density of secondary cavity-nesting birds did not decline...

An aerial radiological survey of the White Oak Creek Floodplain, Oak Ridge Reservation, Oak Ridge, Tennessee: Date of survey: September-October 1986

International Nuclear Information System (INIS)

Fritzsche, A.E.

1987-06-01

An aerial radiological survey was conducted over the White Oak Creek Floodplain of the Oak Ridge Reservation during the period 30 September through 3 October 1986. The survey was performed at the request of the United States Department of Energy (DOE), Oak Ridge Operations Office, by EG and G Energy Measurements, Inc. (EG and G/EM), a contractor of the DOE. The survey results will be utilized in support of the Remedial Action Program being conducted at the site by Martin Marietta Energy Systems, Inc., operator of the Oak Ridge National Laboratory (ORNL). A flight line spacing of 37 meters (120 feet) and a survey altitude of 46 meters (150 feet) yielded the maximum data density and sensitivity achievable by the aerial system, which was greater than that achieved from prior surveys of the entire Oak Ridge Reservation. Isopleth maps of Cs-137, Co-60, Ti-208 implied concentrations, and exposure rates provided an estimate of the location and magnitude of the man-made activity. These maps, overlaid on a current photograph of the area, combine to yield a view of the radiological condition of the White Oak Creek Floodplain. 5 refs., 40 figs., 3 tabs

Farmers' objectives toward their woodlands in the upper Midwest of the United States: implications for woodland volumes and diversity

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W. Keith Moser; Earl C. Leatherberry; Mark H. Hansen; Brett J. Butler

2009-01-01

This paper reports the results of a study that explores the relationship between farm woodland owners' stated intentions for owning woodland, and the structure and composition of these woodlands in the states of Illinois, Indiana and Iowa in the upper Midwest of the United States. Data from two sample-based inventories conducted by the USDA Forest Service, Forest...

Wilderness and woodland ranchers in California: A total income case study of public grazing permits and their impacts on conservation

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Oviedo Pro, J. L.; Huntsinger, L.; Campos, P.; Caparros, A.

2009-04-01

Mediterranean woodlands in California are managed as agro-silvo-pastoral systems producing a number of commercial products as well as a huge variety of environmental services, including private amenities for the landowner. In many parts of the woodlands, grazing on government owned (public) lands has traditionally had an important role in private ranching. In recent decades the risk of conversion to alternative uses (such as urban development or vineyards) has threatened these woodlands due to the increasing opportunity costs of capital. Understanding the economy of these woodlands and the potential effects of public grazing policies on the total income perceived by the landowner is crucial when considering strategies attempting to slow or stop land use change. However, traditional cash-flow analyses are lacking crucial information needed to understand all the elements that have an important role in the economic decisions that landowners make about their woodlands. For more than half a century, the use of public lands by private ranchers has been one of the most controversial debates in the American west. Wilderness conservationist groups have denounced grazing as destructive and argue for the removal of any kind of livestock. Ranchers have fought for their right to hold public grazing leases, arguing that they are crucial for the continuity of private ranching and consequently for the conservation of extensive rangeland habitat that otherwise could be converted to alternative uses. In this study, we apply the Agroforestry Accounting System (AAS) methodology to a California oak woodland case study to estimate the total private income generated in an accounting period. The presented case study is characterized by a household economy with self-employed labour and with part of the grazing dependent on public land leases. The AAS methodology extends traditional cash-flow analysis in order to estimate the total private income that would accurately explain the woodland

Group dynamics of zebra and wildebeest in a woodland savanna: effects of predation risk and habitat density.

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Maria Thaker

Full Text Available BACKGROUND: Group dynamics of gregarious ungulates in the grasslands of the African savanna have been well studied, but the trade-offs that affect grouping of these ungulates in woodland habitats or dense vegetation are less well understood. We examined the landscape-level distribution of groups of blue wildebeest, Connochaetes taurinus, and Burchell's zebra, Equus burchelli, in a predominantly woodland area (Karongwe Game Reserve, South Africa; KGR to test the hypothesis that group dynamics are a function of minimizing predation risk from their primary predator, lion, Panthera leo. METHODOLOGY/PRINCIPAL FINDINGS: Using generalized linear models, we examined the relative importance of habitat type (differing in vegetation density, probability of encountering lion (based on utilization distribution of all individual lions in the reserve, and season in predicting group size and composition. We found that only in open scrub habitat, group size for both ungulate species increased with the probability of encountering lion. Group composition differed between the two species and was driven by habitat selection as well as predation risk. For both species, composition of groups was, however, dominated by males in open scrub habitats, irrespective of the probability of encountering lion. CONCLUSIONS/SIGNIFICANCE: Distribution patterns of wildebeest and zebra groups at the landscape level directly support the theoretical and empirical evidence from a range of taxa predicting that grouping is favored in open habitats and when predation risk is high. Group composition reflected species-specific social, physiological and foraging constraints, as well as the importance of predation risk. Avoidance of high resource open scrub habitat by females can lead to loss of foraging opportunities, which can be particularly costly in areas such as KGR, where this resource is limited. Thus, landscape-level grouping dynamics are species specific and particular to the

Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England

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M. Wilkinson

2012-12-01

Full Text Available The carbon balance of an 80-yr-old deciduous oak plantation in the temperate oceanic climate of the south-east of Great Britain was measured by eddy covariance over 12 yr (1999–2010. The mean annual net ecosystem productivity (NEP was 486 g C m⁻² yr⁻¹ (95% CI of ±73 g C m⁻² yr⁻¹, and this was partitioned into a gross primary productivity (GPP of 2034 ± 145 g C m⁻² yr⁻¹, over a 165 (±6 day growing season, and an annual loss of carbon through respiration and decomposition (ecosystem respiration, R_eco of 1548 ± 122 g C m⁻² yr⁻¹. Although the maximum variation of NEP between years was large (333 g C m⁻² yr⁻¹, the ratio of R_eco/GPP remained relatively constant (0.76 ± 0.02 CI. Some anomalies in the annual patterns of the carbon balance could be linked to particular weather events, such as low summer solar radiation and low soil moisture content (values below 30% by volume. The European-wide heat wave and drought of 2003 did not reduce the NEP of this woodland because of good water supply from the surface-water gley soil. The inter-annual variation in estimated intercepted radiation only accounted for ~ 47% of the variation in GPP, although a significant relationship (p < 0.001 was found between peak leaf area index and annual GPP, which modified the efficiency with which incident radiation was used in net CO₂ uptake. Whilst the spring start and late autumn end of the net CO₂ uptake period varied substantially (range of 24 and 27 days respectively, annual GPP was not related to growing season length. Severe outbreaks of defoliating moth caterpillars, mostly Tortrix viridana L. and Operophtera brumata L., caused considerable damage to the forest canopy in 2009 and 2010, resulting in reduced GPP in these two years. Inter-annual variation in

Continuous ammonium enrichment of a woodland stream: uptake kinetics, leaf decomposition, and nitrification

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Newbold, J D; Elwood, J W; Schulze, M S; Stark, R W; Barmeier, J C

1983-01-01

In order to test for nitrogen limitation and examine ammonium uptake by stream sediments, ammonium hydroxide was added continuously at concentrations averaging 100 /sup +/gl/sup -1/ for 70 days to a second-order reach of Walker Branch, an undisturbed woodland stream in Tennessee. Ammonium uptake during the first 4 h of addition corresponded to adsorption kinetics rather than to first-order uptake or to Michaelis-Menten kinetics. However, the calculated adsorption partition coefficient was two to four orders of magnitude greater than values reported for physical adsorption of ammonium, suggesting that the uptake was largely biotic. Mass balance indicated that the uptake of ammonium from the water could be accounted for by increased nitrogen content in benthic organic detritus. Nitrification, inferred from longitudinal gradients in NO/sub 3/, began soon after enrichment and increased dramatically near the end of the experiment. Both ammonium and nitrate concentrations dropped quickly to near background levels when input ceased, indicating little desorption or nitrification of excess nitrogen stored in the reach. There was no evidence of nitrogen limitation as measured by weight loss, oxygen consumption, phosphorus content, and macroinvertebrate density of red oak leaf packs, or by chlorophyll content and aufwuchs biomass on plexiglass slides. A continuous phosphorus enrichment 1 year earlier had demonstrated phosphorus limitation in Walker Branch. 38 references, 6 figures, 3 tables.

Interaction between fires and elephants in relation to vegetation structure and composition of miombo woodlands in northern Mozambique

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Ribeiro, Natasha Sofia

Miombo woodlands represent one of the most important dry deciduous ecosystems in southern Africa. They provide goods and services for over 80% of the population in the sub-continent. The ecology of this important ecosystem is strongly defined by the trio climate-fire-herbivory. Thus, miombo woodlands have a key role in the regional, and the global, energy, water and carbon balances. Niassa Reserve located in northern Mozambique, embodies the largest and most pristine conservation area of miombo woodlands in the region. It was left abandoned for almost twenty years of armed conflict in Mozambique. Currently it has the lowest human population and the highest density of elephants within miombo woodlands in the country. Fires occur every year within Niassa Reserve. Thus, Niassa Reserve represents a key area to investigate the relationships between vegetation and environmental drivers, a crucial question in miombo woodlands. The goal of this study is to contribute to the understanding of the vegetation dynamics in relation to rainfall, fire and herbivory by elephants. To accomplish this goal, I used an innovative approach within miombo woodlands that couples field and remote sensing data. Field data collection aimed to gather information on woody species composition, structure and production (measured as biomass and leaf area index). Production data was used to calibrate remote sensing data and address large-scale variations in woody vegetation production. The results from this study indicate that there is a gradient of decreasing fire frequency, elephant density and rainfall and increasing woody production from east to west of Niassa Reserve. There is also a varied species composition along the same direction. These results provide information for ecological models predicting ecosystem dynamics under environmental changing conditions. Regionally, this study contributes to the understanding of the fundamental functioning of miombo woodlands and the associated driving

Pretreatment Characteristics of Waste Oak Wood by Ammonia Percolation

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Kim, Jun-Seok; Kim, Hyunjoon; Lee, Jin-Suk; Lee, Joon-Pyo; Park, Soon-Chul

A log of waste oak wood collected from a Korean mushroom farm has been tested for ammonia percolation pretreatment. The waste log has different physical characteristics from that of virgin oak wood. The density of the waste wood was 30% lower than that of virgin oak wood. However, there is little difference in the chemical compositions between the woods. Due to the difference in physical characteristics, the optimal pretreatment conditions were also quite different. While for waste oak the optimum temperature was determined to be 130°C, for virgin oak wood the optimum pretreatment was only achieved at 170°C. Presoaking for 12 h with ammonia solution before pretreatment was helpful to increase the delignification efficiency.

The Subfossil Trunk of Chiarano (TV

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Tiziana Urso

2017-06-01

Full Text Available This paper reports the results of the characterization of a subfossil trunk found buried in the mud of the Piavon canal, at Chiarano (TV, when dredging took place in 2008. The trunk, of imposing dimensions, lacking branches and bark, has a black, deeply cracked and strongly deteriorated outer surface with a carbonized appearance, while internally it has the typical blackish colour of the so-called drowned oak. The studies have demonstrated that it is a tree belonging to the genus Quercus, common oak or sessile oak, that may have been felled between the end of the 12 th and early 14 th century A.D.. Determination of the MWC and residual basic density indicate that the deterioration decreases from the outside inwards; the ash content is high externally and diminishes moving toward the centre. Nowadays, the Piavon is an irrigation canal, but in Venetian times it was navigable and was used for the transport of goods and timber. There were extensive woodlands of common oak and sessile oak all along the Piavon, the size and composition of which is documented in the Venetian cadastres, which also report the distances between the woodlands and the nearest water courses, proof of the importance of river transport for the timber. In particular, an 18 hectare oak woodland is recorded in the Surian cadastre (1569-70 for the villa at Chiarano. The oaks were used by the Republic of Venice mainly for the construction and maintenance of the shipping fleet. The Chiarano trunk, given its age and the area where it was found, may therefore be a trunk felled in Venetian times, perhaps destined for naval use, which was lost during its transport by floating.

Population ecology and conservation of beetles and pseudoscorpions living in hollow oaks in Sweden

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Ranius, T.

2002-01-01

Full Text Available This paper aims at giving a summary of recent research on the habitat requirements and population structure of beetles and pseudoscorpions living in old, hollow oaks in Sweden. An inventory of old oaks in pasture woodlands revealed that the species richness of beetles is higher at sites that are originally open and are still grazed. The trees in these plots are preferred for two reasons: they are more sun-exposed and have a larger trunk diameter. Many species are harmed by forest regrowth and, thus, to preserve the rarer saproxylic fauna it is important to continue the management of areas with old oaks. In four of thirteen species (Osmoderma eremita, Tenebrio opacus, Elater ferrugineus and Larca lata, the occupancy per tree were found to be significantly positively correlated with the number of trees in the stand. This finding is noteworthy as there is little scientific evidence available to support that saproxylic beetles suffer from habitat fragmentation. The population dynamics were investigated on a certain study species, O. eremita. The results suggest that the individuals of each tree could be seen as a local population, and the populations in all occupied trees in a stand together form a metapopulation.

Visual aspects in urban woodland management and planning

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Ode, Åsa

2003-01-01

Urban woodland is an important component of people's everyday environment, both as an attractive environment to visit as well as being an intrinsic part of the surrounding landscape. This thesis focuses on one specific aspect of the urban woodland - the visual. The visual aspect is how most people experience the woodland, both when visiting and as part of their everyday landscape. In order to take visual aspects into account there is a need to have tools and approaches for analysing and descr...

The Land Use and Cover Change in Miombo Woodlands under Community Based Forest Management and Its Implication to Climate Change Mitigation: A Case of Southern Highlands of Tanzania

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Z. J. Lupala

2015-01-01

Full Text Available In Tanzania, miombo woodland is the most significant forest vegetation with both ecological and socioeconomic importance. The vegetation has been threatened from land use and cover change due to unsustainable utilization. Over the past two decades, community based forest management (CBFM has been practiced to address the problem. Given the current need to mitigate global climate change, little is known on the influence of CBFM to the land use and cover change in miombo woodlands and therefore compromising climate change mitigation strategies. This study explored the dynamic of land use and covers change and biomass due to CBFM and established the implication to climate change mitigation. The study revealed increasing miombo woodland cover density with decreasing unsustainable utilization. The observed improvement in cover density and biomass provides potential for climate change mitigation strategies. CBFM also developed solidarity, cohesion, and social control of miombo woodlands illegal extraction. This further enhances permanence, reduces leakage, and increases accountability requirement for carbon credits. Collectively with these promising results, good land use plan at village level and introduction of alternative income generating activities can be among the best options to further reduce land use change and biomass loss in miombo woodlands.

Influencing woodland management using web-based technology

Science.gov (United States)

William R. Thomas; Jeffrey W. Stringer

2011-01-01

The University of Kentucky, Department of Forestry Extension delivered hosted Web-based forestry educational programs ("webinars") in 2009 to promote woodland management in Kentucky and engage county extension agents in forestry programming. These webinars were hosted by county extension agents and attended by woodland owners. This hosted webinar approach was...

Woodland recovery following drought-induced tree mortality across an environmental stress gradient.

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Redmond, Miranda D; Cobb, Neil S; Clifford, Michael J; Barger, Nichole N

2015-10-01

Recent droughts and increasing temperatures have resulted in extensive tree mortality across the globe. Understanding the environmental controls on tree regeneration following these drought events will allow for better predictions of how these ecosystems may shift under a warmer, drier climate. Within the widely distributed piñon-juniper woodlands of the southwestern USA, a multiyear drought in 2002-2004 resulted in extensive adult piñon mortality and shifted adult woodland composition to a juniper-dominated, more savannah-type ecosystem. Here, we used pre- (1998-2001) and 10-year post- (2014) drought stand structure data of individually mapped trees at 42 sites to assess the effects of this drought on tree regeneration across a gradient of environmental stress. We found declines in piñon juvenile densities since the multiyear drought due to limited new recruitment and high (>50%) juvenile mortality. This is in contrast to juniper juvenile densities, which increased over this time period. Across the landscape, piñon recruitment was positively associated with live adult piñon densities and soil available water capacity, likely due to their respective effects on seed and water availability. Juvenile piñon survival was strongly facilitated by certain types of nurse trees and shrubs. These nurse plants also moderated the effects of environmental stress on piñon survival: Survival of interspace piñon juveniles was positively associated with soil available water capacity, whereas survival of nursed piñon juveniles was negatively associated with perennial grass cover. Thus, nurse plants had a greater facilitative effect on survival at sites with higher soil available water capacity and perennial grass cover. Notably, mean annual climatic water deficit and elevation were not associated with piñon recruitment or survival across the landscape. Our findings reveal a clear shift in successional trajectories toward a more juniper-dominated woodland and highlight the

Sap flux density and stomatal conductance of European beech and common oak trees in pure and mixed stands during the summer drought of 2003

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Jonard, F.; André, F.; Ponette, Q.; Vincke, C.; Jonard, M.

2011-10-01

SummarySap flux density of European beech and common oak trees was determined from sap flow measurements in pure and mixed stands during the summer drought of 2003. Eight trees per species and per stand were equipped with sap flow sensors. Soil water content was monitored in each stand at different depths by using time-domain reflectometry (TDR). Leaf area index and vertical root distribution were also investigated during the growing season. From sap flux density ( SFD) data, mean stomatal conductance of individual trees ( G s) was calculated by inverting the Penman-Monteith equation. Linear mixed models were developed to analyse the effects of species and stand type (pure vs. mixed) on SFD and G s and on their sensitivity to environmental variables (vapour pressure deficit ( D), incoming solar radiation ( R G), and relative extractable water ( REW)). For reference environmental conditions, we did not find any tree species or stand type effects on SFD. The sensitivity of SFD to D was higher for oak than for beech in the pure stands ( P sapwood-to-leaf area ratio compared to oak. The sensitivity of G s to REW was higher for beech than for oak and was ascribed to a higher vulnerability of beech to air embolism and to a more sensitive stomatal regulation. The sensitivity of beech G s to REW was lower in the mixed than in the pure stand, which could be explained by a better sharing of the resources in the mixture, by facilitation processes (hydraulic lift), and by a rainfall partitioning in favour of beech.

Native birds and alien insects: spatial density dependence in songbird predation of invading oak gallwasps.

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Karsten Schönrogge

Full Text Available Revealing the interactions between alien species and native communities is central to understanding the ecological consequences of range expansion. Much has been learned through study of the communities developing around invading herbivorous insects. Much less, however, is known about the significance of such aliens for native vertebrate predators for which invaders may represent a novel food source. We quantified spatial patterns in native bird predation of invading gall-inducing Andricus wasps associated with introduced Turkey oak (Quercus cerris at eight sites across the UK. These gallwasps are available at high density before the emergence of caterpillars that are the principle spring food of native insectivorous birds. Native birds showed positive spatial density dependence in gall attack rates at two sites in southern England, foraging most extensively on trees with highest gall densities. In a subsequent study at one of these sites, positive spatial density dependence persisted through four of five sequential week-long periods of data collection. Both patterns imply that invading galls are a significant resource for at least some native bird populations. Density dependence was strongest in southern UK bird populations that have had longest exposure to the invading gallwasps. We hypothesise that this pattern results from the time taken for native bird populations to learn how to exploit this novel resource.

The weight of the past: land-use legacies and recolonization of pine plantations by oak trees.

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Navarro-González, Irene; Pérez-Luque, Antonio J; Bonet, Francisco J; Zamora, Regino

2013-09-01

Most of the world's plantations were established on previously disturbed sites with an intensive land-use history. Our general hypothesis was that native forest regeneration within forest plantations depends largely on in situ biological legacies as a source of propagules. To test this hypothesis, we analyzed native oak regeneration in 168 pine plantation plots in southern Spain in relation to land use in 1956, oak patch proximity, and pine tree density. Historical land-use patterns were determined from aerial photography from 1956, and these were compared with inventory data from 2004-2005 and additional orthophoto images. Our results indicate that oak forest regeneration in pine plantations depends largely on land-use legacies, although nearby, well-conserved areas can provide propagules for colonization from outside the plantation, and pine tree density also affected oak recruit density. More intense land uses in the past meant fewer biological legacies and, therefore, lower likelihood of regenerating native forest. That is, oak recruit density was lower when land use in 1956 was croplands (0.004 +/- 0.002 recruits/m2 [mean +/- SE]) or pasture (0.081 +/- 0.054 recruits/m2) instead of shrubland (0.098 +/- 0.031 recruits/m2) or oak formations (0.314 +/- 0.080 recruits/m2). Our study shows that land use in the past was more important than propagule source distance or pine tree density in explaining levels of native forest regeneration in plantations. Thus, strategies for restoring native oak forests in pine plantations may benefit from considering land-use legacies as well as distance to propagule sources and pine density.

The influence of season on carbon allocation to suberin and other stem components of cork oak saplings.

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Aguado, Pedro L; Curt, M Dolores; Pereira, Helena; Fernández, Jesús

2017-02-01

The growth pattern of cork oak (Quercus suber L.), an important component of South Mediterranean woodlands, is seasonal. Seasonality has been found for shoot, radial and cork ring growth as well as for carbon (C) photoassimilation, nutrients remobilization and water relations, among other physiological aspects. However, little is known about the seasonality of C allocation to cork oak chemical compounds, including suberin, a major component of cork. In order to achieve this goal, an isotopic tracer experiment was conducted using 18-month-old cork oaks so that the fate of C photoassimilated in different seasons could be traced into biochemical (main organic) stem components. Two distinct patterns of C allocation, associated with the stages of active plant growth and dormancy, were identified and described. Evidence was provided that translocation of photoassimilated C to stems does not cease during the dormancy period and that suberin is the major C sink for the C assimilated throughout the whole active growth period, as compared with other stem components. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Historical fire and multidecadal drought as context for piñon - Juniper woodland restoration in western Colorado

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Shinneman, Douglas J.; Baker, William L.

2009-01-01

Fire is known to structure tree populations, but the role of broad-scale climate variability is less clear. For example, the influence of climatic “teleconnections” (the relationship between oceanic–atmospheric fluctuations and anomalous weather patterns across broad scales) on forest age structure is relatively unexplored. We sampled semiarid piñon–juniper (Pinus edulis–Juniperus osteosperma) woodlands in western Colorado, USA, to test the hypothesis that woodland age structures are shaped by climate, including links to oceanic–atmospheric fluctuations, and by past fires and livestock grazing. Low-severity surface fire was lacking, as fire scars were absent, and did not influence woodland densities, but stand-replacing fires served as long-rotation (>400–600 years), stand-initiating events. Old-growth stands (>300 years old) were found in 75% of plots, consistent with a long fire rotation. Juniper and piñon age structures suggest contrasting responses during the past several centuries to dry and wet episodes linked to the Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO). Juniper density increased slightly during periods of drought, positive (warm) AMO (after ∼10-year lag), and negative (cool) PDO. In contrast, piñon populations may still be recovering from a long, drought-filled period (AD 1620–1820), with pulses of recovery favored during cool AMO, warm PDO, and above-average moisture periods. Analysis of 20th-century tree establishment and instrumental climate data corroborate the long-term relationships between age structure and climate. After Euro–American settlement (AD 1881), livestock grazing reduced understory grasses and forbs, reducing competition with tree seedlings and facilitating climate-induced increases in piñons. Thus tree populations in these woodlands are in flux, affected by drought and wet periods linked to oceanic–atmospheric variability, Euro–American livestock grazing, and long

The Influence of Rainfall, Vegetation, Elephants and People on Fire Frequency of Miombo Woodlands, Northern Mozambique

Science.gov (United States)

Ribeiro, N. S.; Okin, G. S.; Shugart, H. H.; Swap, R. J.

2008-12-01

Miombo woodlands are important in southern Africa as they occupy over 50% of the land and, their good and services support a large proportion of people in the region. Anthropogenic fires occur in miombo every year especially in the dry season (May - October). This study explores the influence of annual rainfall, elephant density, human density and corridors, and vegetation on the fire frequency. It was carried out in Niassa Reserve located in northern Mozambique, the largest and more pristine conservation area of miombo woodlands in the world. We used a time series analysis and statistical t-test of MODIS-derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) to explore the relationship between biomass and fire frequency. The influence of rainfall, elephants, people and vegetation on fire return was explored using a stepwise logistic regression analysis. The results of this study indicate that fire frequency is higher in places with high biomass at beginning of the dry season. In these areas fire seems to be more intense and to strongly reduce biomass in the late dry season. Land cover is the strongest predictor of fire frequency, but elephant density, annual rainfall and human corridors are also important.

Habitat preferences of oak-feeding xylophagous beetles in a temperate woodland: implications for forest history and management

Czech Academy of Sciences Publication Activity Database

Vodka, Štěpán; Konvička, Martin; Čížek, Lukáš

2009-01-01

Roč. 13, č. 5 (2009), s. 553-562 ISSN 1366-638X R&D Projects: GA AV ČR KJB600960705; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50070508 Keywords : biodiversity conservation * forest management * oak Subject RIV: EH - Ecology, Behaviour Impact factor: 1.842, year: 2009

Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands

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P. Pinho

2012-03-01

Full Text Available Nitrogen (N has emerged in recent years as a key factor associated with global changes, with impacts on biodiversity, ecosystems functioning and human health. In order to ameliorate the effects of excessive N, safety thresholds such as critical loads (deposition fluxes and levels (concentrations can be established. Few studies have assessed these thresholds for semi-natural Mediterranean ecosystems. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for semi-natural Mediterranean evergreen woodlands. We have considered changes in epiphytic lichen communities, one of the most sensitive comunity indicators of excessive N in the atmosphere. Based on a classification of lichen species according to their tolerance to N we grouped species into response functional groups, which we used as a tool to determine the critical loads and levels. This was done for a Mediterranean climate in evergreen cork-oak woodlands, based on the relation between lichen functional diversity and modelled N deposition for critical loads and measured annual atmospheric ammonia concentrations for critical levels, evaluated downwind from a reduced N source (a cattle barn. Modelling the highly significant relationship between lichen functional groups and annual atmospheric ammonia concentration showed the critical level to be below 1.9 μg m⁻³, in agreement with recent studies for other ecosystems. Modelling the highly significant relationship between lichen functional groups and N deposition showed that the critical load was lower than 26 kg (N ha⁻¹ yr⁻¹, which is within the upper range established for other semi-natural ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should aid development of policies to protect Mediterranean woodlands from the initial effects of excessive N.

Treponemal disease in the middle Archaic to early Woodland periods of the western Tennessee River Valley.

Science.gov (United States)

Smith, Maria Ostendorf

2006-10-01

The high frequency of late prehistoric New World treponemal disease is attributable to the demographic changes concomitant with the adoption of agriculture. However, these demographic changes in group mobility and site density episodically preceded intensive plant domestication, suggesting possible staggered temporal change in observed treponemal disease case frequency. Thirteen convincing and an additional two probable (N = 581) cases of treponemal disease were identified in an eight-site skeletal sample spanning the Middle (6,000-3,000 BCE) to Late (2,500-ca. 1,000 to 500 BCE) Archaic and Early Woodland (500 BCE-0 CE) periods from the western Tennessee River Valley. Treponemal disease cases are infrequent in both the Middle (3/115, 2.6%) and Late (2 to 4 cases, subsistence economy across the Archaic-Woodland temporal boundary in the western Tennessee River Valley remained, as elsewhere, based on intensive hunting and collecting, the demographic corollaries of treponemal disease would apparently not be met. However, the traditional horizon marker of the Woodland period is the adoption of pottery, an activity associated with sedentism.

Mapping Woodland Cover in the Miombo Ecosystem: A Comparison of Machine Learning Classifiers

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Courage Kamusoko

2014-06-01

Full Text Available Miombo woodlands in Southern Africa are experiencing accelerated changes due to natural and anthropogenic disturbances. In order to formulate sustainable woodland management strategies in the Miombo ecosystem, timely and up-to-date land cover information is required. Recent advances in remote sensing technology have improved land cover mapping in tropical evergreen ecosystems. However, woodland cover mapping remains a challenge in the Miombo ecosystem. The objective of the study was to evaluate the performance of decision trees (DT, random forests (RF, and support vector machines (SVM in the context of improving woodland and non-woodland cover mapping in the Miombo ecosystem in Zimbabwe. We used Multidate Landsat 8 spectral and spatial dependence (Moran’s I variables to map woodland and non-woodland cover. Results show that RF classifier outperformed the SVM and DT classifiers by 4% and 15%, respectively. The RF importance measures show that multidate Landsat 8 spectral and spatial variables had the greatest influence on class-separability in the study area. Therefore, the RF classifier has potential to improve woodland cover mapping in the Miombo ecosystem.

The Role of Tree Mortality in Vitality Assessment of Sessile Oak Forests

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Imre Berki

2016-12-01

Full Text Available Background and Purpose: The drought-induced vitality loss of sessile oak (Quercus petraea (Matt. Liebl. has been continuously observed in Hungary for more than three decades. The decrease in stand density as a consequence of drought-induced mortality has not been taken into consideration in most of the monitoring methods. Materials and Methods: Forest stands without any forest intervention during the last 30 years were selected. Quadrats were designated for the analysis in 18 sessile oak stands along a climatic transect in which foliage transparency and stand density were measured. Drought stress was defined by the water balance approach. By combining the foliage transparency and the relative stand density, a new cumulative assessment method of stand level vitality was introduced to get a more realistic picture about the effects of long-term drought (lasting for several decades on the sessile oak forests in South-East Europe. Results: The calculated health status (100% - vital; 0% - dead of the sessile oak stands was between 70-90% in the moist South-West Hungary and below 50% close to its xeric limit. The individual tree-based vitality assessment method gave considerably higher values on 17 out of 18 sites. Conclusions: Forest monitoring should also consider stand level-based tree mortality in oak forests while assessing health condition especially close to its xeric limit. The proposed new method provides a more realistic picture about the effects of climate change on sessile oak stands particularly for forest managers interested in changing in the wood stock of forests.

Vegetation structure and small-scale pattern in Miombo Woodland, Marondera, Zimbabwe

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B. M. Campbell

1995-10-01

Full Text Available The aim ol this paper is to describe woodland structure and small-scale patterning of woody plants at a miombo site, and to relate these to past disturbance and soil properties. Brachystegia spiciformis Benth. and Julbemardia globiflora (Benth. Troupin were the most frequent woody plants at the five hectare site, with size-class distributions which were markedly skewed towards the smaller size classes. The vegetation structure at the site and the increase in basal area over the past thirty years point to considerable disturbance prior to the present protected status. Six woodland subtypes were identified, grouped into two structural types: open and closed woodland. The distribution of woodland subtypes related closely to certain soil properties. It was hypothesized that the distribution of open and closed woodland is stable and a positive feedback mechanism by which this occurs is postulated.

Avian community responses to juniper woodland structure and thinning treatments on the Colorado Plateau

Science.gov (United States)

Crow, Claire; van Riper, Charles

2011-01-01

Federal land managers are increasingly implementing fuels-reduction treatments throughout the western United States with objectives of ecological restoration and fire hazard reduction in pinyon-juniper (Pinus spp.-Juniperus spp.) woodlands. The pinyon-juniper woodland ecosystem complex is highly variable across the western landscape, as is bird community composition. We investigated relations between breeding birds and vegetation characteristics in modified pinyon-juniper woodlands at three sites (BLM, USFS, NPS) on the Colorado Plateau. During the breeding seasons of 2005 and 2006, we surveyed birds and measured vegetation in 74 study plots. These plots were each 3.1 hectares (ha; 7.6 acres), located across the range of natural variation, with 41 control sites and 33 plots in areas previously thinned by hand-cutting or chaining. We found that relations of avian pinyon-juniper specialists and priority species to vegetation characteristics were generally in agreement with the findings of previous studies and known nesting and feeding habits of those birds. Relatively high density of pinyon pines was important to species richness and abundance in 6 of 14 species. Abundance of all species was related to treatment method, and we found no difference in bird communities at chaining and hand-cut sites.

Site factors influencing oak decline in the interior highlands of Arkansas, Missouri, and Oklahoma

Science.gov (United States)

Edward A. Poole; Eric Heitzman; James M. Guldin

2006-01-01

Oak decline is affecting the forests in the Interior Highlands of Arkansas, Missouri, and Oklahoma. In 2002 and 2003, field plots were established throughout the region to evaluate the influence of topographic position and aspect on oak decline. Density and basal area of dead and dying oaks did not significantly differ by either topographic position or aspect. Lack of...

Soil properties linked to Phytophthora cinnamomi presence and oak decline in Iberian dehesas

Science.gov (United States)

Moreno, G.; Vivas, M.; Pérez, A.; Cubera, E.; Madeira, M.; Solla, A.

2009-04-01

Dehesas cover about 3,100,000 ha in the Iberian Peninsula, and support an outstanding diversity of wildlife and flora endemisms. These open woodlands provide Spain and Portugal inhabitants with a high-quality food, derived from animal production, sustain rural population, and act as retardants of soil erosion and desertification, which are considered primary environmental concerns in the Mediterranean basin. Dehesas are considered examples of sustainable use, though in the last few decades intensive land use, imposed by a concomitant change in the technological and socio-economic conditions, and common agricultural policies threat their conservation. Soil compaction and erosion, oak regeneration failure, dieback of old-ageing stands, and loose of biodiversity are some of the most common threats. At the same time, a severe decline of Quercus ilex (Holm oak) has been reported since the 1990s in the southern Iberian Peninsula, and more recently in France, Italy, and Morocco. In the Iberian Peninsula, the decline has been mostly observed in dehesas, where a combination of factors, possibly acting in synergy, have been put forward to explain the disease. Severe drought episodes, flooding, and rapid fluctuations in soil water content have been reported as predisposing factors favoring tree invasion by bark borer insects and/or pathogenic fungi. It is mostly ignored to what extent decline is a natural or a man-induced process, and if it is associated to either basic, management-related soil properties, or both. To bring insight to this problem, extensive and integrative comparisons of some soil properties related to hydromorphism were initiated, comprising pairs of adjacent non-symptomatic and symptomatic Q. ilex trees. In 2008, 48 dehesa stands from western Spain (Cáceres), half of them located along stream banks and the other half located in slopes, were intensively studied. In each stand, soil and root samples were taken under 3 non-symptomatic (healthy) and 3

Cavity-nesting bird use of nest boxes in vineyards of central-coast California

Science.gov (United States)

Daniel P. Mummert; Laura Baines; William D. Tietje

2002-01-01

Oak woodland habitat is being degraded or replaced by vineyards in many areas of central-coastal California. Oak woodlands are home to many insectivorous, cavity-nesting birds that would be beneficial in and around vineyards. During March to June 2001, we used bluebird nest boxes to study nest box use and productivity of cavity-nesting birds in vineyards versus...

A spatial statistical analysis of cork oak competition in two Portuguese silvopastoral systems

NARCIS (Netherlands)

Paulo, M.J.; Stein, A.; Tomé, M.

2002-01-01

This paper considers competition among cork oaks (Quercus suber L.) at three plots in two representative Portuguese stands. It uses spatial point pattern functions to describe densities and quantify differences among stands. Relations between cork oak characteristics and indices measuring intertree

Woodland as working space: where is the restorative green idyll?

Science.gov (United States)

Bingley, Amanda

2013-08-01

Much has been written on the beneficial, restorative qualities of 'natural' (non-built) rural or urban 'green' space, including woodland, in promoting mental and physical health when accessed for leisure, sport and education. In contrast, with the exception of rural health studies, there is relatively little debate about the health benefits of 'green space' as work place, especially in woodland and forests. In the developed world, this apparent gap in the literature may be partly due to an assumption of the forest work place as inherently healthy, and also the invisibility of a tiny percentage of the workforce now employed in forestry. However, in the UK and parts of Europe over recent years there has been a small, though significant, increase in opportunities to train and work in woodlands using traditional, sustainable management such as coppicing, and an exploration of health issues of woodland work is timely. This paper reports on findings from a secondary narrative analysis of oral history interviews selected from two phases of the Woodland Recollections Project and newsletters written by local people historically and currently engaged in coppicing and woodland work in North West England. Perceptions of healthy working in green space are examined by applying key concepts of Attention Restoration Theory (ART). Findings suggest that woodland work environments involve many counter-restorative factors that can render the 'green idyll' detrimental to health and wellbeing. To benefit from restorative elements requires drawing on a high level of specialist skills that empower individuals to manage and maintain healthy working practices in these diverse and challenging environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Socialist and postsocialist land-use legacies determine farm woodland composition and structure

DEFF Research Database (Denmark)

Plieninger, Tobias; Schaich, H.

2014-01-01

and structure of presocialist woodlands. We argue that forest conservation planning should actively consider land-use legacies, which are of particular relevance in the landscapes of Central and Eastern Europe, as these have undergone multiple, abrupt, and severe land-use transitions....... explicit assessment of differences in species richness, diversity, and evenness as well as forest physiognomy and structure among Eastern German farm woodlands established during (1) the presocialist era (until 1945), (2) the socialist era (1945-1990), and (3) the postsocialist era (after 1990). Aerial...... imagery was used to allocate woodlands to one of the three eras, after which a forest inventory of 120 woodlands was performed. The results show substantial differences in forest composition and structure. Presocialist-era woodlands are composed of native (mean 96 %), deciduous (mean 94 %) tree species...

Oak habitat recovery on California's largest islands: Scenarios for the role of corvid seed dispersal

Science.gov (United States)

Pesendorfer, Mario B.; Baker, Christopher M.; Stringer, Martin; McDonald-Madden, Eve; Bode, Michael; McEachern, A. Kathryn; Morrison, Scott A.; Sillett, T. Scott

2018-01-01

Seed dispersal by birds is central to the passive restoration of many tree communities. Reintroduction of extinct seed dispersers can therefore restore degraded forests and woodlands. To test this, we constructed a spatially explicit simulation model, parameterized with field data, to consider the effect of different seed dispersal scenarios on the extent of oak populations. We applied the model to two islands in California's Channel Islands National Park (USA), one of which has lost a key seed disperser.We used an ensemble modelling approach to simulate island scrub oak (Quercus pacifica) demography. The model was developed and trained to recreate known population changes over a 20-year period on 250-km2 Santa Cruz Island, and incorporated acorn dispersal by island scrub-jays (Aphelocoma insularis), deer mice (Peromyscus maniculatus) and gravity, as well as seed predation. We applied the trained model to 215-km2 Santa Rosa Island to examine how reintroducing island scrub-jays would affect the rate and pattern of oak population expansion. Oak habitat on Santa Rosa Island has been greatly reduced from its historical extent due to past grazing by introduced ungulates, the last of which were removed by 2011.Our simulation model predicts that a seed dispersal scenario including island scrub-jays would increase the extent of the island scrub oak population on Santa Rosa Island by 281% over 100 years, and by 544% over 200 years. Scenarios without jays would result in little expansion. Simulated long-distance seed dispersal by jays also facilitates establishment of discontinuous patches of oaks, and increases their elevational distribution.Synthesis and applications. Scenario planning provides powerful decision support for conservation managers. We used ensemble modelling of plant demographic and seed dispersal processes to investigate whether the reintroduction of seed dispersers could provide cost-effective means of achieving broader ecosystem restoration goals on

Interactions between Canopy Structure and Herbaceous Biomass along Environmental Gradients in Moist Forest and Dry Miombo Woodland of Tanzania.

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Deo D Shirima

Full Text Available We have limited understanding of how tropical canopy foliage varies along environmental gradients, and how this may in turn affect forest processes and functions. Here, we analyse the relationships between canopy leaf area index (LAI and above ground herbaceous biomass (AGBH along environmental gradients in a moist forest and miombo woodland in Tanzania. We recorded canopy structure and herbaceous biomass in 100 permanent vegetation plots (20 m × 40 m, stratified by elevation. We quantified tree species richness, evenness, Shannon diversity and predominant height as measures of structural variability, and disturbance (tree stumps, soil nutrients and elevation as indicators of environmental variability. Moist forest and miombo woodland differed substantially with respect to nearly all variables tested. Both structural and environmental variables were found to affect LAI and AGBH, the latter being additionally dependent on LAI in moist forest but not in miombo, where other factors are limiting. Combining structural and environmental predictors yielded the most powerful models. In moist forest, they explained 76% and 25% of deviance in LAI and AGBH, respectively. In miombo woodland, they explained 82% and 45% of deviance in LAI and AGBH. In moist forest, LAI increased non-linearly with predominant height and linearly with tree richness, and decreased with soil nitrogen except under high disturbance. Miombo woodland LAI increased linearly with stem density, soil phosphorous and nitrogen, and decreased linearly with tree species evenness. AGBH in moist forest decreased with LAI at lower elevations whilst increasing slightly at higher elevations. AGBH in miombo woodland increased linearly with soil nitrogen and soil pH. Overall, moist forest plots had denser canopies and lower AGBH compared with miombo plots. Further field studies are encouraged, to disentangle the direct influence of LAI on AGBH from complex interrelationships between stand

Interactions between Canopy Structure and Herbaceous Biomass along Environmental Gradients in Moist Forest and Dry Miombo Woodland of Tanzania.

Science.gov (United States)

Shirima, Deo D; Pfeifer, Marion; Platts, Philip J; Totland, Ørjan; Moe, Stein R

2015-01-01

We have limited understanding of how tropical canopy foliage varies along environmental gradients, and how this may in turn affect forest processes and functions. Here, we analyse the relationships between canopy leaf area index (LAI) and above ground herbaceous biomass (AGBH) along environmental gradients in a moist forest and miombo woodland in Tanzania. We recorded canopy structure and herbaceous biomass in 100 permanent vegetation plots (20 m × 40 m), stratified by elevation. We quantified tree species richness, evenness, Shannon diversity and predominant height as measures of structural variability, and disturbance (tree stumps), soil nutrients and elevation as indicators of environmental variability. Moist forest and miombo woodland differed substantially with respect to nearly all variables tested. Both structural and environmental variables were found to affect LAI and AGBH, the latter being additionally dependent on LAI in moist forest but not in miombo, where other factors are limiting. Combining structural and environmental predictors yielded the most powerful models. In moist forest, they explained 76% and 25% of deviance in LAI and AGBH, respectively. In miombo woodland, they explained 82% and 45% of deviance in LAI and AGBH. In moist forest, LAI increased non-linearly with predominant height and linearly with tree richness, and decreased with soil nitrogen except under high disturbance. Miombo woodland LAI increased linearly with stem density, soil phosphorous and nitrogen, and decreased linearly with tree species evenness. AGBH in moist forest decreased with LAI at lower elevations whilst increasing slightly at higher elevations. AGBH in miombo woodland increased linearly with soil nitrogen and soil pH. Overall, moist forest plots had denser canopies and lower AGBH compared with miombo plots. Further field studies are encouraged, to disentangle the direct influence of LAI on AGBH from complex interrelationships between stand structure, environmental

Stocking equations for regeneration in mixed oak stands

Science.gov (United States)

Songlin Fei; Kim C. Steiner; James C. Finley

2007-01-01

Regeneration stocking equations for mixed-oak stands were developed based on data collected from nearly 14,000 plots in the central Appalachians. Maximum stand density was identified by plotting aggregate height against number of seedlings per plot, and was used as the reference level of the average maximum stand density (100 percent stocking or A-level stocking)....

Do Quercus ilex woodlands undergo abrupt non-linear functional changes in response to human disturbance along a climatic gradient?

Science.gov (United States)

Bochet, Esther; García-Fayos, Patricio; José Molina, Maria; Moreno de las Heras, Mariano; Espigares, Tíscar; Nicolau, Jose Manuel; Monleon, Vicente

2017-04-01

Theoretical models predict that drylands are particularly prone to suffer critical transitions with abrupt non-linear changes in their structure and functions as a result of the existing complex interactions between climatic fluctuations and human disturbances. However, so far, few studies provide empirical data to validate these models. We aim at determining how holm oak (Quercus ilex) woodlands undergo changes in their functions in response to human disturbance along an aridity gradient (from semi-arid to sub-humid conditions), in eastern Spain. For that purpose, we used (a) remote-sensing estimations of precipitation-use-efficiency (PUE) from enhanced vegetation index (EVI) observations performed in 231x231 m plots of the Moderate Resolution Imaging Spectroradiometer (MODIS); (b) biological and chemical soil parameter determinations (extracellular soil enzyme activity, soil respiration, nutrient cycling processes) from soil sampled in the same plots; (c) vegetation parameter determinations (ratio of functional groups) from vegetation surveys performed in the same plots. We analyzed and compared the shape of the functional change (in terms of PUE and soil and vegetation parameters) in response to human disturbance intensity for our holm oak sites along the aridity gradient. Overall, our results evidenced important differences in the shape of the functional change in response to human disturbance between climatic conditions. Semi-arid areas experienced a more accelerated non-linear decrease with an increasing disturbance intensity than sub-humid ones. The proportion of functional groups (herbaceous vs. woody cover) played a relevant role in the shape of the functional response of the holm oak sites to human disturbance.

Effects of soil pollutants, biogeochemistry and microbiology on the distribution and composition of enchytraeid communities in urban and suburban holm oak stands

International Nuclear Information System (INIS)

Rota, Emilia; Caruso, Tancredi; Monaci, Fabrizio; Baldantoni, Daniela; De Nicola, Flavia; Iovieno, Paola; Bargagli, Roberto

2013-01-01

Holm oaks form typical urban woodlands in the Mediterranean region. We aimed at characterizing the enchytraeid communities in these environments and searching for possible correlations with soil parameters, including the traffic contamination. Samples of litter and topsoil were collected at different spatial scales and seasons in Naples and Siena cities and in two suburban stands. Only the co-variation between pollution and other soil chemico-physical factors showed significant effects, whereas no direct effect of soil microbiology was detected. Some thermophilous Fridericia and Achaeta tolerate high concentrations of heavy metals and PAHs and their abundance was mainly determined by Ca bioavailability. Central-European mesophilous species increased significantly under more temperate environmental conditions. Different combinations of soil cohesiveness, grain size composition and moisture regime seem to select species of certain body sizes. -- Highlights: •We examined the enchytraeid assemblages of urban holm oak stands in relation to pollution gradients. •Only the co-variation between pollution and other soil chemico-physical factors showed significant effects. •Thermophilous species in Fridericia and Achaeta are mainly affected by Ca bioavailability. -- The co-variation between pollution and other soil chemico-physical factors affects significantly the enchytraeid communities in Mediterranean urban holm oak stands

Silvics and silviculture in the southwestern pinyon-juniper woodlands

Science.gov (United States)

Gerald J. Gottfried

2004-01-01

Southwestern pinyon-juniper and juniper woodlands cover large areas of the western United States. The woodlands have been viewed as places of beauty and sources of valuable resource products or as weed-dominated landscapes that hinder the production of forage for livestock. They are special places because of the emotions and controversies that encircle their management...

The Charcoal Trap: Miombo woodlands versus the energy needs of people

Science.gov (United States)

Merbold, Lutz; Maurice, Muchinda; Mukufute M, Mukelabai; J, Scholes Robert; Waldemar, Ziegler; L, Kutsch Werner

2010-05-01

Miombo woodlands cover the transition zone between the dry open savannas and the moist forests in Southern Africa and occupy the vast area of 2.7 Mio km2. These ecosystems are highly disturbed by deforestation, mostly for charcoal production. Charcoal has become the largest source to satisfy urban energy demands. Even though when charcoal is a less energy-efficient fuel compared to firewood but by having higher energy densities and thus being cheaper to transport. Over the last decades, charcoal production has become a full-time employment for migrant workers, resulting in very different and no longer sustainable deforestation patterns. Strategies to reduce the pressure on the miombo woodlands have to take aspects of employment and energy demand into account. The objectives of the study were to examine above- and belowground carbon losses from an intact miombo woodland (protected forest reserve) in comparison to a highly disturbed surrounding area due to charcoal production. Detection of changes in carbon concentrations and stocks were made possible by applying biomass- and soil inventories as well as the eddy-covariance method. These local results were up-scaled to countrywide estimates of carbon lost to the atmosphere by deforestation in addition to carbon losses fossil fuel combustion. The results show, that in the worst case scenario which does not assume any regeneration, a developing country as Zambia, can easily emit as much carbon per capita as a developed Western world country such as France, when deforestation is included in the national inventory (up to 9.1 t of CO2 per capita). However, regeneration is very probably when post-harvest disturbance is low. Further studies on miombo regeneration are highly demanded.

Carbon dioxide fluxes from a degraded woodland in West Africa and their responses to main environmental factors.

Science.gov (United States)

Ago, Expedit Evariste; Serça, Dominique; Agbossou, Euloge Kossi; Galle, Sylvie; Aubinet, Marc

2015-12-01

In West Africa, natural ecosystems such as woodlands are the main source for energy, building poles and livestock fodder. They probably behave like net carbon sinks, but there are only few studies focusing on their carbon exchange with the atmosphere. Here, we have analyzed CO 2 fluxes measured for 17 months by an eddy-covariance system over a degraded woodland in northern Benin. Specially, temporal evolution of the fluxes and their relationships with the main environmental factors were investigated between the seasons. This study shows a clear response of CO 2 absorption to photosynthetic photon flux density (Q p ), but it varies according to the seasons. After a significant and long dry period, the ecosystem respiration (R) has increased immediately to the first significant rains. No clear dependency of ecosystem respiration on temperature has been observed. The degraded woodlands are probably the "carbon neutral" at the annual scale. The net ecosystem exchange (NEE) was negative during wet season and positive during dry season, and its annual accumulation was equal to +29 ± 16 g C m -2 . The ecosystem appears to be more efficient in the morning and during the wet season than in the afternoon and during the dry season. This study shows diurnal and seasonal contrasted variations in the CO 2 fluxes in relation to the alternation between dry and wet seasons. The Nangatchori site is close to the equilibrium state according to its carbon exchanges with the atmosphere. The length of the observation period was too short to justify the hypothesis about the "carbon neutrality" of the degraded woodlands at the annual scale in West Africa. Besides, the annual net ecosystem exchange depends on the intensity of disturbances due to the site management system. Further research works are needed to define a woodland management policy that might keep these ecosystems as carbon sinks.

The heterogeneity of wooded-agricultural landscape mosaics influences woodland bird community assemblages

OpenAIRE

Neumann, Jessica L.; Griffiths, Geoffrey H.; Foster, Christopher W.; Holloway, Graham J.

2016-01-01

Context\\ud Landscape heterogeneity (the composition and configuration of different landcover types) plays a key role in shaping woodland bird assemblages in wooded-agricultural mosaics. Understanding how species respond to landscape factors could contribute to preventing further decline of woodland bird populations.\\ud Objective\\ud To investigate how woodland birds with different species traits respond to landscape heterogeneity, and to identify whether specific landcover types are important ...

Behavioural strategies towards human disturbances explain individual performance in woodland caribou.

Science.gov (United States)

Leclerc, Martin; Dussault, Christian; St-Laurent, Martin-Hugues

2014-09-01

Behavioural strategies may have important fitness, ecological and evolutionary consequences. In woodland caribou, human disturbances are associated with higher predation risk. Between 2004 and 2011, we investigated if habitat selection strategies of female caribou towards disturbances influenced their calf's survival in managed boreal forest with varying intensities of human disturbances. Calf survival was 53% and 43% after 30 and 90 days following birth, respectively, and 52% of calves that died were killed by black bear. The probability that a female lose its calf to predation was not influenced by habitat composition of her annual home range, but decreased with an increase in proportion of open lichen woodland within her calving home range. At the local scale, females that did not lose their calf displayed stronger avoidance of high road density areas than females that lost their calf to predation. Further, females that lost their calf to predation and that had a low proportion of ≤5-year-old cutovers within their calving home range were mostly observed in areas where these young cutovers were locally absent. Also, females that lost their calf to predation and that had a high proportion of ≤5-year-old cutovers within their calving home range were mostly observed in areas with a high local density of ≤5-year-old cutovers. Our study demonstrates that we have to account for human-induced disturbances at both local and regional scales in order to further enhance effective caribou management plans. We demonstrate that disturbances not only impact spatial distribution of individuals, but also their reproductive success.

Energetic implications of disturbance caused by petroleum exploration to woodland caribou

International Nuclear Information System (INIS)

Bradshaw, C.J.A.; Boutin, S.

1998-01-01

A study was conducted to determine if there is a link between the decline in woodland caribou populations and petroleum exploration activity in the province of Alberta. To do this, a simple model was developed to estimate the energy costs of multiple encounters with disturbances (such as noise). The goal was to determine if woodland caribou in northeastern Alberta have been exposed to enough disturbances between 1988 and 1993 to cause winter mass loss to exceed either 15 per cent autumn mass or 20 per cent autumn mass. It was concluded that disturbance can have major energetic consequences for woodland caribou. Simulations have shown that petroleum exploration has biological consequences on woodland caribou, but it is difficult to infer long-term population effects from petroleum exploration. 50 refs., 2 tabs., 1 fig

Sustaining recruitment of oak reproduction in uneven-aged stands in the Ozark Highlands.

Science.gov (United States)

David R. Larsen; Edward F. Loewenstein; Paul S. Johnson

1999-01-01

Successful application of the single-tree selection system in Ozark oak forests depends on sustaining adequate recruitment of reproduction into the overstory. In turn, this requires maintaining stand density at ecologically appropriate levels. The ecological requirements for oak recruitment are discussed and guiding curves are presented that meet those requirements...

Longleaf pine forests and woodlands: old growth under fire!

Science.gov (United States)

Joan L. Walker

1999-01-01

The author discusses a once widespread forest type of the Southeast – longleaf pine dominated forests and woodlands. This system depends on fire – more or less frequent, and often of low intensity. Because human-mediated landscape fragmentation has drastically changed the behavior of fire on longleaf pine dominated landscapes, these forests and woodlands will never be...

Sudden oak death disease progression in oaks and tanoaks

Science.gov (United States)

Brice A. McPherson; Sylvia R. Mori; David L. Wood; Andrew J. Storer; Pavel Svihra; N. Maggi Kelly; Richard B. Standiford

2006-01-01

In March 2000, we established twenty disease progression plots in Marin County to monitor the progress of sudden oak death symptoms in coast live oak (Quercus agrifolia), California black oak (Q. kelloggii), and tanoak (Lithocarpus densiflorus) (McPherson and others 2005). Plots were located to encompass a...

Fire effects on Gambel oak in southwestern ponderosa pine-oak forests

Science.gov (United States)

Scott R. Abella; Peter Z. Fulé

2008-01-01

Gambel oak (Quercus gambelii) is ecologically and aesthetically valuable in southwestern ponderosa pine (Pinus ponderosa) forests. Fire effects on Gambel oak are important because fire may be used in pine-oak forests to manage oak directly or to accomplish other management objectives. We used published literature to: (1) ascertain...

[Effects of fire recurrence on fire behaviour in cork oak woodlands (Quercus suber L.) and Mediterranean shrublands over the last fifty years].

Science.gov (United States)

Schaffhauser, Alice; Pimont, François; Curt, Thomas; Cassagne, Nathalie; Dupuy, Jean-Luc; Tatoni, Thierry

2015-12-01

Past fire recurrence impacts the vegetation structure, and it is consequently hypothesized to alter its future fire behaviour. We examined the fire behaviour in shrubland-forest mosaics of southeastern France, which were organized along a range of fire frequency (0 to 3-4 fires along the past 50 years) and had different time intervals between fires. The mosaic was dominated by Quercus suber L. and Erica-Cistus shrubland communities. We described the vegetation structure through measurements of tree height, base of tree crown or shrub layer, mean diameter, cover, plant water content and bulk density. We used the physical model Firetec to simulate the fire behaviour. Fire intensity, fire spread, plant water content and biomass loss varied significantly according to fire recurrence and vegetation structure, mainly linked to the time since the last fire, then the number of fires. These results confirm that past fire recurrence affects future fire behaviour, with multi-layered vegetation (particularly high shrublands) producing more intense fires, contrary to submature Quercus woodlands that have not burnt since 1959 and that are unlikely to reburn. Further simulations, with more vegetation scenes according to shrub and canopy covers, will complete this study in order to discuss the fire propagation risk in heterogeneous vegetation, particularly in the Mediterranean area, with a view to a local management of these ecosystems. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Spatio-Temporal Trends of Oak Decline and Mortality under Periodic Regional Drought in the Ozark Highlands of Arkansas and Missouri

Science.gov (United States)

Zhaofei Fan; Xiuli Fan; Michael K. Crosby; W. Keith Moser; Hong He; Martin A. Spetich; Stephen R. Shifley

2012-01-01

At the forest landscape/region level, based on annual Forest Inventory and Analysis plot data from 1999 to 2010, oak decline and mortality trends for major oak species (groups) were examined in the Ozark Highlands of Arkansas and Missouri. Oak decline has elevated cumulative mortality of red oak species to between 11 and 15 percent in terms of relative density and...

Ancient woodland boundaries in Europe

Czech Academy of Sciences Publication Activity Database

Szabó, Péter

2010-01-01

Roč. 36, č. 2 (2010), s. 205-214 ISSN 0305-7488 R&D Projects: GA AV ČR IAA600050812 Institutional research plan: CEZ:AV0Z60050516 Keywords : ancient woodland * historical ecology * landscape archaeology Subject RIV: EF - Botanics Impact factor: 0.983, year: 2010

Variation in flood tolerance of container-grown seedlings of swamp white oak, bur oak, and white oak

Science.gov (United States)

Michael P. Walsh; J.W. Van Sambeek; Mark V. Coggeshall

2008-01-01

How much variation in flood tolerance exists among seedlings within oak species, given the flood frequency of sites from which acorns are collected, has been largely unexplored. Our studies examined initial growth and flood tolerance for seedlings of swamp white oak (Quercus bicolor Willd.), bur oak (Q. macrocarpa L.), and white...

Oak mortality associated with crown dieback and oak borer attack in the Ozark Highlands

Science.gov (United States)

Zhaofei Fan; John M. Kabrick; Martin A. Spetich; Stephen R. Shifley; Randy G. Jensen

2008-01-01

Oak decline and related mortality have periodically plagued upland oak–hickory forests, particularly oak species in the red oak group, across the Ozark Highlands of Missouri, Arkansas and Oklahoma since the late 1970s. Advanced tree age and periodic drought, as well as Armillaria root fungi and oak borer attack are believed to contribute to oak decline and mortality....

Soil phytoliths from miombo woodlands in Mozambique

Science.gov (United States)

Mercader, Julio; Bennett, Tim; Esselmont, Chris; Simpson, Steven; Walde, Dale

2011-01-01

This paper describes topsoil phytolith assemblages from 25 loci underneath miombo woodlands on an eco-transect intersecting the Mozambican Rift along a geographical, altitudinal, climatic and botanical gradient. We provide the first comprehensive overview of the phytolith spectrum that defines northern Mozambique's Zambezian floristic zone. Our classifying criteria derive from comparison with previously described and quantified reference collections of trees and grasses growing in the study area. We characterize the sedimentological and soil features of the matrices where phytoliths are found, establishing correlation among geo-edaphic variables and phytoliths. Descriptive statistics along with nonparametric and parametric statistical analyses evaluate phytolith grouping criteria, variation, robustness, and membership. From a taphonomic perspective, we attest that topsoil phytolith assemblages are polygenic and do not represent an episodic snapshot of extant vegetation, but a palimpsest from plants representing various disturbance episodes, succession stages, and ecological trends. Phytoliths retrieved from Mozambican miombo soils do not seem to trace altitudinal, temperature, or precipitation gradients, and no significant differences exist between highland and lowland phytolith assemblages. This article provides a phytolith analog for woodland environments that can guide future paleoenvironmental research. It also confirms that phytolith analysis is able to detect shifts in the woodland/grassland interface.

Small mammals in successional prairie woodlands of the northern Great Plains

Science.gov (United States)

Mark A. Rumble; John E. Gobeille

2001-01-01

Prairie woodlands comprise about 1 percent of the landscape in the northern Great Plains. However, prairie woodlands provide habitat for far more than 1 percent of the wildlife species that occur in the prairie region. With increasing pressures on natural resources, managers need methods for managing wildlife habitat and biodiversity that are based on ecological...

Environmental Survey Report for ORNL: Small Mammal Abundance and Distribution Survey Oak Ridge National Environmental Research Park 2009 - 2010

Energy Technology Data Exchange (ETDEWEB)

Giffen, Neil R [ORNL; Reasor, R. Scott [Oak Ridge Institute for Science and Education (ORISE); Campbell, Claire L. [Oak Ridge Institute for Science and Education (ORISE)

2009-12-01

This report summarizes a 1-year small mammal biodiversity survey conducted on the Oak Ridge National Environmental Research Park (OR Research Park). The task was implemented through the Oak Ridge National Laboratory (ORNL) Natural Resources Management Program and included researchers from the ORNL Environmental Sciences Division, interns in the Oak Ridge Institute for Science and Education Higher Education Research Experiences Program, and ORNL Environmental Protection Services staff. Eight sites were surveyed reservation wide. The survey was conducted in an effort to determine species abundance and diversity of small mammal populations throughout the reservation and to continue the historical inventory of small mammal presence for biodiversity records. This data collection effort was in support of the approved Wildlife Management Plan for the Oak Ridge Reservation, a major goal of which is to maintain and enhance wildlife biodiversity on the Reservation. Three of the sites (Poplar Creek, McNew Hollow, and Deer Check Station Field) were previously surveyed during a major natural resources inventory conducted in 1996. Five new sites were included in this study: Bearden Creek, Rainy Knob (Natural Area 21), Gum Hollow, White Oak Creek and Melton Branch. The 2009-2010 small mammal surveys were conducted from June 2009 to July 2010 on the Oak Ridge National Environmental Research Park (OR Research Park). The survey had two main goals: (1) to determine species abundance and diversity and (2) to update historical records on the OR Research Park. The park is located on the Department of Energy-owned Oak Ridge Reservation, which encompasses 13,580 ha. The primary focus of the study was riparian zones. In addition to small mammal sampling, vegetation and coarse woody debris samples were taken at certain sites to determine any correlations between habitat and species presence. During the survey all specimens were captured and released using live trapping techniques including

Woodland restoration in Scotland: ecology, history, culture, economics, politics and change.

Science.gov (United States)

Hobbs, Richard

2009-07-01

In the latter half of the 20th century, native pine woodlands in Scotland were restricted to small remnant areas within which there was little regeneration. These woodlands are important from a conservation perspective and are habitat for numerous species of conservation concern. Recent developments have seen a large increase in interest in woodland restoration and a dramatic increase in regeneration and woodland spread. The proximate factor enabling this regeneration is a reduction in grazing pressure from sheep and, particularly, deer. However, this has only been possible as a result of a complex interplay between ecological, political and socio-economic factors. We are currently seeing the decline of land management practices instituted 150-200 years ago, changes in land ownership patterns, cultural revival, and changes in societal perceptions of the Scottish landscape. These all feed into the current move to return large areas of the Scottish Highlands to tree cover. I emphasize the need to consider restoration in a multidisciplinary framework which accounts not just for the ecology involved but also the historical and cultural context.

Effects of urban density on carbon dioxide exchanges: observations of dense urban, suburban and woodland areas of southern England

OpenAIRE

Ward, H.C.; Kotthaus, S.; Grimmond, C.S.B.; Bjorkegren, A.; Wilkinson, M.; Morrison, W.T.J.; Evans, J.G.; Morison, J.I.L.; Iamarino, M.

2015-01-01

Anthropogenic and biogenic controls on the surface-atmosphere exchange of CO2 are explored for three different environments. Similarities are seen between suburban and woodland sites during summer, when photosynthesis and respiration determine the diurnal pattern of the CO2 flux. In winter, emissions from human activities dominate urban and suburban fluxes; building emissions increase during cold weather, while traffic is a major component of CO2 emissions all year round. Observed CO2 fluxes ...

An aerial radiological survey of the Oak Ridge Reservation, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Maurer, R.J.

1993-04-01

An aerial radiological survey of the Oak Ridge Reservation (ORR) and surrounding area in Oak Ridge, Tennessee, was conducted during the period March 30 to April 14,1992. The purpose of the survey was to measure and document the terrestrial radiological environment of the Oak Ridge Reservation for use in environmental management programs and emergency response planning. The aerial survey was flown at an altitude of 150 feet (46 meters) along a series of parallel lines 250 feet (76 meters) apart and included X-10 (Oak Ridge National Laboratory), K-25 (former Gaseous Diffusion Plant), Y-12 (Weapons Production Plant), the Freels Bend Area and Oak Ridge Institute for Science and Education, the East Fork Poplar Creek (100-year floodplain extending from K-25 to Y-12), Elza Gate (former uranium ore storage site located in the city of Oak Ridge), Parcel A, the Clinch River (river banks extending from Melton Hill Dam to the city of Kingston), and the CSX Railroad Tracks (extending from Y-12 to the city of Oak Ridge). The survey encompassed approximately 55 square miles (1 41 square kilometers) of the Oak Ridge Reservation and surrounding area

75 FR 44853 - Woodlands Bank, Bluffton, SC; Notice of Appointment of Receiver

Science.gov (United States)

2010-07-29

... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Woodlands Bank, Bluffton, SC; Notice of... the Home Owners' Loan Act, the Office of Thrift Supervision has duly appointed the Federal Deposit Insurance Corporation as sole Receiver for Woodlands Bank, Bluffton, South Carolina (OTS No. 08464), as of...

Relative abundance of mesopredators and size of oak patches in the cross-timbers ecoregion

Science.gov (United States)

Disney, M.R.; Hellgren, E.C.; Davis, C.A.; Leslie, David M.; Engle, David M.

2008-01-01

Mesopredators (e.g., raccoon Procyon lotor, Virginia opossum Didelphis virginiana, striped skunk Mephitis mephitis) have received considerable attention because of links to population declines in birds via increased nest predation, especially in landscapes fragmented by anthropogenic forces. Relationships of abundance of mesopredators to size of habitat patches have received less attention than relationships to other metrics of fragmentation, particularly edge characteristics. We tested the hypothesis that relative abundance of mesopredators (e.g., raccoons and Virginia opossums) was related negatively to size of forest patch. We delineated 15 patches of oak (Quercus) forest ranging from 0.2 to 55.3 ha within a grassland-woodland mosaic in the cross-timbers ecoregion of Oklahoma. Scent stations and live traps within these patches were used to index relative abundance of mesopredators in summers 2003 and 2004. Both indices of relative abundance were related weakly and negatively to area of forest patch. However, rate of capture and visitation to scent station were not correlated consistently throughout the study. Our results suggested that the two methods to index abundance provided separate information on functional and numerical responses to size of patch. Our evidence that mesopredators within the cross timbers were more likely to be in smaller patches of oak forest may have implications to success of avian nesting in these patches.

Insects affecting establishment of northern red oak seedlings in central Pennsylvania

Science.gov (United States)

J. Galford; L.R. Auchmoody; H.C. Smith; R.S. Walters

1991-01-01

Studies to evaluate the impact of insects on the establishment of advance oak regeneration in Pennsylvania were initiated in 1989. The populations and species of insects feeding on germinating acorns and new seedlings, their activity periods, and the damage caused by these insects were studied in relation to overstory-density (40, 60, and 100 percent relative density)...

Interspecific gene flow and maintenance of species integrity in oaks

Directory of Open Access Journals (Sweden)

Oliver Gailing

2014-07-01

Full Text Available Oak species show a wide variation in morphological and physiological characters, and species boundaries between closely related species are often not clear-cut. Still, despite frequent interspecific gene flow, oaks maintain distinct morphological and physiological adaptations. In sympatric stands, spatial distribution of species with different ecological requirements is not random but constrained by soil and other microenvironmental factors. Pre-zygotic isolation (e.g. cross incompatibilities, asynchrony in flowering, pollen competition and post-zygotic isolation (divergent selection contribute to the maintenance of species integrity in sympatric oak stands. The antagonistic effects of interspecific gene flow and divergent selection are reflected in the low genetic differentiation between hybridizing oak species at most genomic regions interspersed by regions with signatures of divergent selection (outlier regions. In the near future, the availability of high-density genetic linkage maps anchored to scaffolds of a sequenced Q. robur genome will allow to characterize the underlying genes in these outlier regions and their putative role in reproductive isolation between species. Reciprocal transplant experiments of seedlings between parental environments can be used to characterize selection on outlier genes. High transferability of gene-based markers will enable comparative outlier screens in different oak species.

Grassland to woodland transitions: Dynamic response of microbial community structure and carbon use patterns

Science.gov (United States)

Creamer, Courtney A.; Filley, Timothy R.; Boutton, Thomas W.; Rowe, Helen I.

2016-06-01

Woodland encroachment into grasslands is a globally pervasive phenomenon attributed to land use change, fire suppression, and climate change. This vegetation shift impacts ecosystem services such as ground water allocation, carbon (C) and nutrient status of soils, aboveground and belowground biodiversity, and soil structure. We hypothesized that woodland encroachment would alter microbial community structure and function and would be related to patterns in soil C accumulation. To address this hypothesis, we measured the composition and δ13C values of soil microbial phospholipids (PLFAs) along successional chronosequences from C4-dominated grasslands to C3-dominated woodlands (small discrete clusters and larger groves) spanning up to 134 years. Woodland development increased microbial biomass, soil C and nitrogen (N) concentrations, and altered microbial community composition. The relative abundance of gram-negative bacteria (cy19:0) increased linearly with stand age, consistent with decreases in soil pH and/or greater rhizosphere development and corresponding increases in C inputs. δ13C values of all PLFAs decreased with time following woody encroachment, indicating assimilation of woodland C sources. Among the microbial groups, fungi and actinobacteria in woodland soils selectively assimilated grassland C to a greater extent than its contribution to bulk soil. Between the two woodland types, microbes in the groves incorporated relatively more of the relict C4-C than those in the clusters, potentially due to differences in below ground plant C allocation and organo-mineral association. Changes in plant productivity and C accessibility (rather than C chemistry) dictated microbial C utilization in this system in response to shrub encroachment.

Evergreen oak leaves as natural monitor in environmental pollution

International Nuclear Information System (INIS)

Capannesi, G.; Rosada, A.; Caroli, S.

1988-01-01

Evergreen oak was chosen as a possible biological monitor of environmental pollution. It was shown that there was a direct relationship between the concentration of elements in leaves and the presence of pollution sources, i.e. the density of vehicular traffic. (author) 12 figs.; 3 tabs

Alien plant invasions in European woodlands

NARCIS (Netherlands)

Wagner, Viktoria; Chytrý, Milan; Jiménez-Alfaro, Borja; Pergl, Jan; Hennekens, Stephan; Biurrun, Idoia; Knollová, Ilona; Berg, Christian; Vassilev, Kiril; Rodwell, John S.; Škvorc, Željko; Jandt, Ute; Ewald, Jörg; Jansen, Florian; Tsiripidis, Ioannis; Botta-Dukát, Zoltán; Casella, Laura; Attorre, Fabio; Rašomavičius, Valerijus; Ćušterevska, Renata; Schaminée, Joop H.J.; Brunet, Jörg; Lenoir, Jonathan; Svenning, Jens Christian; Kącki, Zygmunt; Petrášová-Šibíková, Mária; Šilc, Urban; García-Mijangos, Itziar; Campos, Juan Antonio; Fernández-González, Federico; Wohlgemuth, Thomas; Onyshchenko, Viktor; Pyšek, Petr

2017-01-01

Aim: Woodlands make up a third of European territory and carry out important ecosystem functions, yet a comprehensive overview of their invasion by alien plants has never been undertaken across this continent. Location: Europe. Methods: We extracted data from 251,740 vegetation plots stored in the

Radionuclide behaviour in a coniferous woodland ecosystem in Cumbria, UK

International Nuclear Information System (INIS)

Jones, S.R.; Copplestone, D.; Johnson, M.S.

1996-01-01

The behaviour of 134Cs, 137Cs, 238Pu, 239+240Pu and 241Am, in food chains in a semi-natural woodland has been investigated and doses to the ecosystem due to the presence of these radionuclides of anthropogenic origin have been assessed. The woodland is located within 1 km of the coastal British Nuclear Fuels plc (BNFL) reprocessing plant at Sellafield, Cumbria (O.S. Grid Reference: NY 037045) and has received an input of radionuclides primarily through atmospheric discharges from the Sellafield site throughout its operational history of more than 40 years. Deposition has been enhanced by interception by the canopy, such that deposits in the woodland are significantly higher than adjacent pasture land. Within the wood, deposition is greatest along the front (or leading) edge in relation to aerosols transported to the woodland from Sellafield, due to the 'edge effect'. Despite the high radionuclide deposits, relatively low uptake and mobility within the ecosystem was observed. Estimated doses to the ecosystem at around 2 mGy a -1 , were dominated by external irradiation and were well below the levels thought to be necessary to harm terrestrial ecosystems. A provisional conclusion at this stage is that the measures taken to control emissions from Sellafield in line with radiological protection standards for humans have also been adequate to protect this potentially vulnerable ecosystem

Chloroplast DNA footprints of postglacial recolonization by oaks

Science.gov (United States)

Petit, Rémy J.; Pineau, Emmanuel; Demesure, Brigitte; Bacilieri, Roberto; Ducousso, Alexis; Kremer, Antoine

1997-01-01

Recolonization of Europe by forest tree species after the last glaciation is well documented in the fossil pollen record. This spread may have been achieved at low densities by rare events of long-distance dispersal, rather than by a compact wave of advance, generating a patchy genetic structure through founder effects. In long-lived oak species, this structure could still be discernible by using maternally transmitted genetic markers. To test this hypothesis, a fine-scale study of chloroplast DNA (cpDNA) variability of two sympatric oak species was carried out in western France. The distributions of six cpDNA length variants were analyzed at 188 localities over a 200 × 300 km area. A cpDNA map was obtained by applying geostatistics methods to the complete data set. Patches of several hundred square kilometers exist which are virtually fixed for a single haplotype for both oak species. This local systematic interspecific sharing of the maternal genome strongly suggests that long-distance seed dispersal events followed by interspecific exchanges were involved at the time of colonization, about 10,000 years ago. PMID:11038572

Element Pool Changes within a Scrub-Oak Ecosystem after 11 Years of Exposure to Elevated CO2

Science.gov (United States)

Duval, Benjamin D.; Dijkstra, Paul; Drake, Bert G.; Johnson, Dale W.; Ketterer, Michael E.; Megonigal, J. Patrick; Hungate, Bruce A.

2013-01-01

The effects of elevated CO2 on ecosystem element stocks are equivocal, in part because cumulative effects of CO2 on element pools are difficult to detect. We conducted a complete above and belowground inventory of non-nitrogen macro- and micronutrient stocks in a subtropical woodland exposed to twice-ambient CO2 concentrations for 11 years. We analyzed a suite of nutrient elements and metals important for nutrient cycling in soils to a depth of ∼2 m, in leaves and stems of the dominant oaks, in fine and coarse roots, and in litter. In conjunction with large biomass stimulation, elevated CO2 increased oak stem stocks of Na, Mg, P, K, V, Zn and Mo, and the aboveground pool of K and S. Elevated CO2 increased root pools of most elements, except Zn. CO2-stimulation of plant Ca was larger than the decline in the extractable Ca pool in soils, whereas for other elements, increased plant uptake matched the decline in the extractable pool in soil. We conclude that elevated CO2 caused a net transfer of a subset of nutrients from soil to plants, suggesting that ecosystems with a positive plant growth response under high CO2 will likely cause mobilization of elements from soil pools to plant biomass. PMID:23717607

The development of an approach to assess critical loads of acidity for woodland habitats in Great Britain

Directory of Open Access Journals (Sweden)

S. J. Langan

2004-01-01

Full Text Available Alongside other countries that are signatories to the UNECE Convention Long Range Transboundary on Air Pollution, the UK is committed to reducing the impact of air pollution on the environment. To advise and guide this policy in relation to atmospheric emissions of sulphur and nitrogen, a critical load approach has been developed. To assess the potential impact of these pollutants on woodland habitats a steady state, simple mass balance model has been parameterised. For mineral soils, a Ca:Al ratio in soil solution has been used as the critical load indicator for potential damage. For peat and organic soils critical loads have been set according to a pH criterion. Together these approaches have been used with national datasets to examine the potential scale of acidification in woodland habitats across the UK. The results can be mapped to show the spatial variability in critical loads of the three principal woodland habitat types (managed coniferous, managed broadleaved/ mixed woodland and unmanaged woodland. The results suggest that there is a wide range of critical loads. The most sensitive (lowest critical loads are associated with managed coniferous followed by unmanaged woodland on peat soils. Calculations indicate that at steady state, acid deposition inputs reported for 1995–1997 result in a large proportion of all the woodland habitats identified receiving deposition loads in excess of their critical load; i.e. critical loads are exceeded. These are discussed in relation to future modelled depositions for 2010. Whilst significant widespread negative impacts of such deposition on UK woodland habitats have not been reported, the work serves to illustrate that if acid deposition inputs were maintained and projected emissions reductions not achieved, the long-term sustainability of large areas of woodland in the UK could be compromised. Keywords: critical loads, acid deposition, acidification, woodland, simple mass balance model

Comparing single-tree selection, group selection, and clearcutting for regenerating oaks and pines in the Missouri Ozarks

Science.gov (United States)

Randy G. Jensen; John M. Kabrick

2008-01-01

In the Missouri Ozarks, there is considerable concern about the effectiveness of the uneven-aged methods of single-tree selection and group selection for oak (Quercus L.) and shortleaf pine (Pinus echinata Mill.) regeneration. We compared the changes in reproduction density of oaks and pine following harvesting by single-tree...

Woodland in Practical Skills Therapeutic Education

Science.gov (United States)

Mata, Paula; Gibons, Kenneth; Mata, Fernando

2016-01-01

Modern urban life provides less opportunities to contact with nature, which is a potential cause of developmental deviances in children. We investigated the potential therapeutic effect of woodlands, within the context of Practical Skills Therapeutic Education at the Ruskin Mill College, UK. Data on physical and emotional perceptions were…

Risk analysis and guidelines for harvest activities in wisconsin oak timberlands to minimize oak wilt threat

Science.gov (United States)

Jennifer Juzwik; Jane Cummings-Carlson; Kyoko Scanlon

2010-01-01

Oaks (Quercus spp.) are an important species group in the forests of Wisconsin. The State’s timberland typed as oak-hickory forest was estimated at 2.9 million acres in 1996. Growing stock volume for red oak was estimated at 2.4 billion cubic feet, whereas select white oak volume was estimated to be 927 million cubic feet. Oak wilt, the oak disease...

Lignin-derived oak phenolics: a theoretical examination of additional potential health benefits of red wine.

Science.gov (United States)

Setzer, William N

2011-08-01

Lignin-derived phenolic compounds can be extracted from oak barrels during the aging of red wine, and it is hypothesized that these compounds may contribute to the health benefits of red wine by their antioxidant, radical-scavenging, or chemopreventive activities. Density functional calculations (B3LYP/6-311++G) support the radical-scavenging abilities of the oak phenolics. Sinapaldehyde, syringaldehyde, syringol, and syringylacetone all have bond dissociation energies that are lower than resveratrol and comparable to the flavonoid catechin. Molecular docking studies of the oak phenolics with known resveratrol protein targets also show that these compounds dock favorably to the protein targets. Thus, lignin-derived oak phenolics, although found in small concentrations, may contribute to the beneficial antioxidant, chemopreventive, and cardioprotective effects of red wine.

Woodland expansion in South African grassy biomes based on satellite observations (1990-2013): general patterns and potential drivers.

Science.gov (United States)

Skowno, Andrew L; Thompson, Mark W; Hiestermann, Jens; Ripley, Brad; West, Adam G; Bond, William J

2017-06-01

Increases in woody plant cover in savanna grassland environments have been reported on globally for over 50 years and are generally perceived as a threat to rangeland productivity and biodiversity. Despite this, few attempts have been made to estimate the extent of woodland increase at a national scale, principally due to technical constraints such as availability of appropriate remote sensing products. In this study, we aimed to measure the extent to which woodlands have replaced grasslands in South Africa's grassy biomes. We use multiseason Landsat data in conjunction with satellite L-band radar backscatter data to estimate the extent of woodlands and grasslands in 1990 and 2013. The method employed allows for a unique, nationwide measurement of transitions between grassland and woodland classes in recent decades. We estimate that during the 23-year study period, woodlands have replaced grasslands over ~57 000 km 2 and conversely that grasslands have replaced woodlands over ~30 000 km 2 , a net increase in the extent of woodland of ~27 000 km 2 and an annual increase of 0.22%. The changes varied markedly across the country; areas receiving over 500 mm mean annual precipitation showed higher rates of woodland expansion than regions receiving 0.19% yr -1 ). The woodland change map presented here provides a unique opportunity to test the numerous models of woody plant encroachment at a national/regional scale. © 2016 John Wiley & Sons Ltd.

Testing Extended Accounts in Scheduled Conservation of Open Woodlands with Permanent Livestock Grazing: Dehesa de la Luz Estate Case Study, Arroyo de la Luz, Spain

Directory of Open Access Journals (Sweden)

Pablo Campos

2017-11-01

Full Text Available Standard Economic Accounts for Agriculture and Forestry do not measure the ecosystem services and intermediate products embedded in the final products recorded, and omit the private non-commercial intermediate products and self-consumption of private amenities. These limitations of the standard accounts are addressed by the extended Agroforestry Accounting System, which is being tested at the publicly-owned Dehesa de la Luz agroforestry estate. The extended accounts simulate conservation forestry of holm oak and cork oak for the current as well as successive rotation cycles during which scheduled conservation of the cultural woodland landscape of the Dehesa de la Luz is carried out, improving the natural physical growth of the firewood and cork. The estimated results for 2014 reveal that private ecosystem services make up 50% of the firewood and grazing products consumed; the private environmental income accounts for 13% of the total private income; and the private environmental asset represents 53% of the total opening capital. The net value added is more than 2.3 times the amount estimated using the standard accounts. The landowner donates intermediate products of non-commercial services at a value of 85 €/ha, which are used to enhance the supply of public products.

Laboratory characterization of PM emissions from combustion of wildland biomass fuels

Science.gov (United States)

Seyedehsan Hosseini; Shawn Urbanski; P. Dixit; Qi Li; Ian Burling; Robert Yokelson; Timothy E. Johnson; Manish Sharivastava; Heejung Jung; David R. Weise; Wayne Miller; David Cocker

2013-01-01

Particle emissions from open burning of southwestern (SW) and southeastern (SE) U.S. fuel types during 77 controlled laboratory burns are presented. The fuels include SW vegetation types: ceanothus, chamise/scrub oak, coastal sage scrub, California sagebrush, manzanita, maritime chaparral, masticated mesquite, oak savanna, and oak woodland, as well as SE vegetation...

Assessing Methods to Protect Susceptible Oak and Tanoak Stands from Sudden Oak Death

Science.gov (United States)

Tedmund Swiecki; Elizabeth Bernhardt

2010-01-01

Landowners and managers have been seeking ways to protect susceptible oak (Quercus) species and tanoak (Lithocarpus densiflorus) from sudden oak death (SOD) caused by Phytophthora ramorum. Because disease epidemiology differs between tanoaks and susceptible oaks, we are testing different control strategies...

Stable oxygen isotope analysis reveal vegetation influence on soil water movement and ecosystem water fluxes in a semi-arid oak woodland

Science.gov (United States)

Piayda, Arndt; Dubbert, Maren; Werner, Christiane; Cuntz, Matthias

2015-04-01

Mechanistically disentangling the role and function of vegetation within the hydrological cycle is one of the key questions in the interdisciplinary field of ecohydrology. The presence of vegetation can have various impacts on soil water relations: transpiration of active vegetation causes great water losses, rainfall is intercepted, soil evaporation can be reduced and infiltration, hydraulic redistribution and translatory flow might be altered. In drylands, covering around 40% of the global land surface, the carbon cycle is closely coupled to water availability due to (seasonal) droughts. Specifically savannah type ecosystems, which cover large areas worldwide, are, due to their bi-layered structure, very suitable to study the effects of distinct vegetation types on the ecosystem water cycle. Oxygen isotope signatures (δ18O) have been used to partition ecosystem evapotranspiration (ET ) because of the distinct isotopic compositions of water transpired by leaves relative to soil evaporated vapor. Recent developments in laser spectroscopy enable measurements of δ18O in the vapor phase with high temporal resolution in the field and bear a novel opportunity to trace water movement within the ecosystem. In the present study, the effects of distinct vegetation layers (i.e. trees and herbaceous vegetation) on soil water infiltration and redistribution as well as ecosystem water fluxes in a Mediterranean cork-oak woodland are disentangled. An irrigation experiment was carried out using δ18O labeled water to quantify the distinct effects of trees and herbaceous vegetation on 1) infiltration and redistribution of water in the soil profile and 2) to disentangle the effects of tree cover on the contribution of unproductive soil evaporation and understory transpiration to total ET . First results proof that stable δ18O isotopes measured onsite with laser spectroscopy is a valuable tool to trace water movement in the soil showing a much higher sensitivity than common TDR

Thermoregulatory capabilities of the woodland dormouse ...

African Journals Online (AJOL)

We measured metabolism and thermoregulation in woodland dormice acclimated to long-day length, moderate temperature and abundant food over a temperature range (Ta) of approximately 5–37°C. The thermal neutral zone for this species lay between 29 and 35°C. Estimated resting metabolic rate (RMR) within this ...

Oak Dispersal Syndromes: Do Red and White Oaks Exhibit Different Dispersal Srategies?

Science.gov (United States)

Michael Steele; Peter Smallwood; William B. Terzaghi; John E. Carlson; Thomas conteras; Amy McEuen

2004-01-01

We provide an overview of the ecological and evolutionary interactions between oaks and several of their dispersal agents, and review a series of studies that demonstrate how various acorn characteristics affect feeding and caching decisions of these animals, which in turn may influence oak dispersal and establishment. We demonstrate that acorns of red oak species show...

Effects of short-rotation controlled burning on amphibians and reptiles in pine woodlands

Science.gov (United States)

Roger W. Perry; D. Craig Rudolph; Ronald E. Thill

2012-01-01

Fire is being used increasingly as a forest management tool throughout North America, but its effects on reptiles and amphibians in many ecosystems are unclear. Open woodlands with understories dominated by herbaceous vegetation benefit many wildlife species, but maintaining these woodlands requires frequent burning. Although many studies have compared herpetofaunal...

Nest-site selection and nest survival of Lewis's woodpecker in aspen riparian woodlands

Science.gov (United States)

Karen R. Newlon; Victoria A. Saab

2011-01-01

Riparian woodlands of aspen (Populus tremuloides) provide valuable breeding habitat for several cavity-nesting birds. Although anecdotal information for this habitat is available for Lewis's Woodpecker (Melanerpes lewis), no study has previously examined the importance of aspen woodlands to this species' breeding biology. From 2002 to 2004, we monitored 76...

Perceived personal safety in relation to urban woodland vegetation – A review

OpenAIRE

Jansson, Märit; Fors, Hanna; Lindgren, Therese; Wiström, Björn

2013-01-01

Urban woodland vegetation provides people with many aesthetic, ecological and psychological benefits, but can also generate problems concerning people’s perception of safety. This paper reviews existing knowledge about perceived personal safety in relation to vegetation, particularly woodland vegetation, in urban green spaces such as parks and residential areas. Individual and social factors, but also vegetation character, maintenance and design, proved to be important for perceived personal ...

Arborealities: The Tactile Ecology of Hardy’s Woodlanders

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William A. Cohen

2014-10-01

Full Text Available This article asks what consequences two recent movements in scholarship - affect theory and environmental studies - might have for understanding the Victorian tactile imagination. Thomas Hardy's 1887 novel 'The Woodlanders' provides a means of addressing this question, for it shares with posthumanist critics a view that people are material things in a world of things, and that the world is itself a collection of vital agencies and networked actors. Hardy shows how a tactile modality provides a point of entry into discussions of both affect and ecology, situating the human in a proximate, contiguous relation to both bodily and environmental materialities. 'The Woodlanders' offers a world in which trees, in particular, work on - and are in turn worked on by - human objects; a world in which, one might say, the trees are people and the people are trees. This arboreality is far from a sentimental oneness with nature, nor is it an exercise in anthropomorphization. Instead, it provides a recognition of the inhuman, material, and sensate aspects of the human; or, perhaps better, of the human as rooted, budding, leafy, and abloom. Like some recent theoretical accounts, 'The Woodlanders' disperses agency among human and non-human elements alike, employing a tactile mode of representation to break down distinctions between them. Normal 0 false false false EN-US X-NONE X-NONE

Foliar nutrients explain goldspotted oak borer, Agrilus auroguttatus, adult feeding preference among four California oak species

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Yigen Chen; Tom. W. Coleman; Michael. I. Jones; Mary. L. Flint; Steven. J. Seybold

2013-01-01

Adults of the invasive goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), consumed foliar weight in no-choice feeding tests of, in descending order, California black oak Quercus kelloggii Newb., Engelmann oak, Quercus engelmannii Greene, coast live oak, Quercus...

Successful de-fragmentation of woodland by planting in an agricultural landscape? An assessment based on landscape indicators.

Science.gov (United States)

Quine, C P; Watts, K

2009-01-01

Habitat fragmentation is the focus of much conservation concern and associated research. In some countries, such as Britain, the main phase of fragmentation occurred centuries ago and the focus of conservation management is now on restoration and recovery. Scenario studies have suggested that spatial targeting is preferable if landscape scale restoration is to be achieved, and that this should bring greater benefits than site-focussed activities but this has rarely been tested in practice. In Britain, woodland expansion has been encouraged through a number of financial incentives, which have evolved from instruments that encouraged almost any addition to the potential woodland resource, to grant schemes that have set out to restore connectivity to remnant ancient woodland. This study assessed the degree of de-fragmentation achieved by woodland expansion on the Isle of Wight and in particular the success of spatial targeting of new woodland planting implemented through grant aid in the JIGSAW (Joining and Increasing Grant Scheme for Ancient Woodland) scheme. Five steps in the re-development of broad-leaved woodland were tested using eight indicators - six commonly used landscape metrics, and two ecologically scaled indicators derived from application of least-cost network evaluation. Only half of the measures indicated de-fragmentation over the whole sequence of five steps. However, the spatial targeting did appear successful, when compared to equivalent untargeted grant-aided woodland expansion, and resulted in positive change to six of the eight indicators. We discuss the utility of the indicators and ways in which future targeting could be supported by their application.

Detection of soil erosion with Thematic Mapper (TM) satellite data within Pinyon-Juniper woodlands

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Price, Kevin Paul

1987-01-01

Pinyon-Juniper woodlands dominate approximately 24.3 million hectares (60 million acres) in the western United States. The overall objective was to test the sensitivity of the LANDSAT Thematic Mapper (TM) spectral data for detecting varying degrees of soil erosion within the Pinyon-Juniper woodlands. A second objective was to assess the potential of the spectral data for assigning the Universal Soil Loss Equation (USLE) crop management (C) factor values to varying cover types within the woodland. Thematic Mapper digital data for June 2, 1984 on channels 2, 3, 4, and 5 were used. Digital data analysis was performed using the ELAS software package. Best results were achieved using CLUS, an unsupervised clustering algorithm. Fifteen of the 40 Pinyon-Juniper signatures were identified as being relatively pure Pinyon-Juniper woodland. Final analysis resulted in the grouping of the 15 signatures into three major groups. Ten study sites were selected from each of the three groups and located on the ground. At each site the following field measurements were taken: percent tree canopy and percent understory cover, soil texture, total soil loss, and soil erosion rate estimates. A technique for measuring soil erosion within Pinyon-Juniper woodlands was developed. A theoretical model of site degradation after Pinyon-Juniper invasion is presented.

Reproductive traits and number of matings in males and females of Cerambyx welensii (Coleoptera: Cerambycidae) an emergent pest of oaks.

Science.gov (United States)

Torres-Vila, L M; Mendiola-Diaz, F J; Conejo-Rodríguez, Y; Sánchez-González, Á

2016-06-01

The longhorn beetle Cerambyx welensii is an emerging pest involved in oak decline episodes, whose damage is increasingly reported in dehesa open woodlands. Knowledge of the reproductive biology of C. welensii is a crucial goal due to its new pest status. In this study, we assess the reproductive traits of both sexes in the laboratory (25°C and 60% relative humidity ). In females, body length was 44.9 ± 0.9 mm (mean ± SE), fecundity 132 ± 12 eggs, fertility 70 ± 1 %, longevity 70 ± 3 days, preoviposition period 2 ± 0.2 days, oviposition period 44 ± 3 days and postoviposition period 19 ± 3 days. Fecundity was positively correlated with female size, longevity and oviposition period. Daily fecundity was 3.0 ± 0.2 eggs/day and showed a fluctuating synovigenic pattern with a slight decreasing trend over time. Egg length was 4.24 ± 0.01 mm and egg volume 8.14 ± 0.04 mm3. Egg size was correlated with female size but the relative size of eggs was larger in smaller females. Incubation time was 13.9 ± 0.1 days and hatching did not depend on egg size. Neonate size was positively correlated with egg length. Females were polyandrous (more than 20 lifetime matings) but multiple mating did not increase fecundity, fertility or longevity. In males, body length was 43.7 ± 0.6 mm and longevity 52 ± 3 days. Unlike with females, longevity was positively correlated with male size. Males were polygynous (up to 30 lifetime matings) but mating history did not affect male longevity. Rather to the contrary, long-lived males mated more times because they had more mating chances. Lastly, C. welensii reproductive traits were compared with those other Cerambycidae species and discussed from an adaptive perspective. Our data will be useful to improve management of C. welensii in order to prevent or mitigate its impact in dehesa woodlands and other oak forests.

An integrative analysis of the dynamics of landscape- and local-scale colonization of Mediterranean woodlands by Pinus halepensis.

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Efrat Sheffer

Full Text Available Afforestation efforts have resulted in extensive plantations of either native or non-native conifers, which in many regions has led to the spread of those conifers into surrounding natural vegetation. This process of species colonization can trigger profound changes in both community dynamics and ecosystem processes. Our study disentangled the complexity of a process of colonization in a heterogeneous landscape into a simple set of rules. We analyzed the factors that control the colonization of natural woodland ecosystems by Pinus halepensis dispersing from plantations in the Mediterranean region of Israel. We developed maximum-likelihood models to explain the densities of P. halepensis colonizing natural woodlands. Our models unravel how P. halepensis colonization is controlled by factors that determine colonization pressure by dispersing seeds and by factors that control resistance to colonization of the natural ecosystems. Our models show that the combination of different seed arrival processes from local, landscape, and regional scales determine pine establishment potential, but the relative importance of each component varied according to seed source distribution. Habitat resistance, determined by abiotic and biotic conditions, was as important as propagule input in determining the density of pine colonization. Thus, despite the fact that pine propagules disperse throughout the landscape, habitat heterogeneity within the natural ecosystems generates significant variation in the actual densities of colonized pine. Our approach provides quantitative measures of how processes at different spatial scales affect the distribution and densities of colonizing species, and a basis for projection of expected distributions. Variation in colonization rates, due to landscape-scale heterogeneity in both colonization pressure and resistance to colonization, can be expected to produce a diversity of new ecosystems. This work provides a template for

Unsustainable charcoal production as a contributing factor to woodland fragmentation in southeast Kenya

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Ruuska, Eeva

2013-06-01

Full Text Available Drawing from a holistic research approach, this paper contributes to the studies of land cover change and sustainable development in Kenya, and to the planning of sustainable future in Dakatcha Woodland, SE Kenya. As an un-protected global hotspot for biodiversity, Dakatcha Woodland has suffered from unsustainable forest resource use. The relation of charcoal production to land cover change and its socio-economic impact are studied in detail. A supervised land cover classification formed using four SPOT satellite images from 2005/06 and 2011 revealed that the woodland is fragmenting and the Important Bird Area (IBA demarcation should be reconsidered. Through in-situ observation, household questionnaires and semi-structured expert interviews it was found that more than half of the 90 households assessed are involved in charcoal production which is higher figure than peer studies have suggested, and that the charcoal network offers income to many, but bears an negative impact on the environment. It was discovered that, like in Kenya, in Dakatcha Woodland, too, the demand for woodfuels (charcoal and fuelwood is one of the key drivers of deforestation and land degradation. As such, woodfuel energy is a cross cutting issue, tying together forest resources, livelihoods and sustainable development, and thus demands further research. Forest management of Dakatcha Woodland must be planned in accordance with all stakeholders in a sustainable manner, drawing from agroforestry and participatory forest management systems, and keeping environmental factors in mind for the maintenance of ecosystem services.

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO₂ exposure in a subtropical oak woodland.

Science.gov (United States)

Hungate, Bruce A; Dijkstra, Paul; Wu, Zhuoting; Duval, Benjamin D; Day, Frank P; Johnson, Dale W; Megonigal, J Patrick; Brown, Alisha L P; Garland, Jay L

2013-11-01

Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂. We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer (15) N in ecosystem components throughout the experiment. Elevated CO₂ increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO₂ increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term (15) N tracer indicated that CO₂ exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO₂ on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO₂ in current biogeochemical models, where the effect of elevated CO₂ on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Predicting Polylepis distribution: vulnerable and increasingly important Andean woodlands

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Brian R. Zutta

2012-11-01

Full Text Available Polylepis woodlands are a vital resource for preserving biodiversity and hydrological functions, which will be altered by climate change and challenge the sustainability of local human communities. However, these highaltitude Andean ecosystems are becoming increasingly vulnerable due to anthropogenic pressure including fragmentation, deforestation and the increase in livestock. Predicting the distribution of native woodlands has become increasingly important to counteract the negative effects of climate change through reforestation and conservation. The objective of this study was to develop and analyze the distribution models of two species that form extensive woodlands along the Andes, namely Polylepis sericea and P. weberbaueri. This study utilized the program Maxent, climate and remotely sensed environmental layers at 1 km resolution. The predicted distribution model for P. sericea indicated that the species could be located in a variety of habitats along the Andean Cordillera, while P. weberbaueri was restricted to the high elevations of southern Peru and Bolivia. For both species, elevation and temperature metrics were the most significant factors for predicted distribution. Further model refinement of Polylepis and other Andean species using increasingly available satellite data demonstrate the potential to help define areas of diversity and improve conservation strategies for the Andes.

Classification and mapping of the composition and structure of dry woodland and savanna in the eastern Okavango Delta

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Michelle J. Tedder

2013-02-01

Full Text Available The dry woodland and savanna regions of the Okavango Delta form a transition zone between the Okavango Swamps and the Kalahari Desert and have been largely overlooked in terms of vegetation classification and mapping. This study focused on the species composition and height structure of this vegetation, with the aim of identifying vegetation classes and providing a vegetation map accompanied by quantitative data. Two hundred and fifty-six plots (50 m × 50 m were sampled and species cover abundance, total cover and structural composition were recorded. The plots were classified using agglomerative, hierarchical cluster analysis using group means and Bray-Curtis similarity and groups described using indicator species analysis. In total, 23 woody species and 28 grass species were recorded. Acacia erioloba and Colophospermum mopane were the most common woody species, whilst Urochloa mossambicensis, Panicum maximum, Dactyloctenium gigantiumand Eragrostis lehmanniana were the most widespread grasses. Eleven vegetation types were identified, with the most widespread being Short mixed mopane woodland, Tall mopane woodland and Tall mixed mopane woodland, covering 288.73 km2 (28%, 209.14 km2 (20% and 173.30 km2 (17% of the area, respectively. Despite their extensive area, these three vegetation types were the least species-rich, whilst Palm thornveld, Short mixed broadleaf woodland and Open mixed Acacia woodland were the most taxonomically variable. By contrast, Closed mixed Acacia woodland and Closed Acacia–Combretum woodland had the most limited distribution, accounting for less than 1% of the mapped area each.Conservation implications: The dry woodland and savanna vegetation of the Okavango Delta comprises a much wider suite of plant communities than the Acacia-dominated and Mopane-dominated classifications often used. This classification provided a more detailed understanding of this vegetation and essential background information for monitoring

Small mammal populations and ecology in the Kings River Sustainable Forest Ecosystems Project area

Science.gov (United States)

William F. Jr. Laudenslayer; Roberta J. Fargo

2002-01-01

Small mammals are important components of woodlands and forests. Since 1992, we have been studying several aspects of small mammal ecology in oak woodlands in western foothills of the southern Sierra Nevada. Assemblages of small, nocturnal mammal species are dominated by the brush mouse (Peromyscus boylii), California mouse (P. californicus...

Mapping decadal land cover changes in the woodlands of north eastern Namibia using the Landsat satellite archive (1975-2014)

Science.gov (United States)

Wingate, Vladimir; Phinn, Stuart; Kuhn, Nikolaus

2016-04-01

Woodland savannahs provide essential ecosystem functions and services to communities. On the African continent, they are widely utilized and converted to intensive land uses. This study investigates the land cover changes over 108,038 km2 in NE Namibia using multi-sensor Landsat imagery, at decadal intervals from 1975 to 2014, with a post-classification change detection method and supervised Regression Tree classifiers. We discuss likely impacts of land tenure and reforms over the past four decades on changes in land use and land cover. These included losses, gains and exchanges between predominant land cover classes. Exchanges comprised logical conversions between woodland and agricultural classes, implying woodland clearing for arable farming, cropland abandonment and vegetation succession. The dominant change was a reduction in the area of the woodland class due to the expansion of the agricultural class, specifically, small-scale cereal and pastoral production. Woodland area decreased from 90% of the study area in 1975 to 83% in 2014, while cleared land increased from 9% to 14%. We found that the main land cover changes are conversion from woodland to agricultural and urban land uses, driven by urban expansion and woodland clearing for subsistence-based agriculture and pastoralism.

Habitat suitability—density relationship in an endangered woodland species: the case of the Blue Chaffinch (Fringilla polatzeki

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Luis M. Carrascal

2017-09-01

Full Text Available Background Understanding constraints to the distribution of threatened species may help to ascertain whether there are other suitable sectors for reducing the risks associated with species that are recorded in only one protected locality, and to inform about the suitability of other areas for reintroduction or translocation programs. Methods We studied the Gran Canaria blue chaffinch (Fringilla polatzeki, a habitat specialist endemic of the Canary Islands restricted to the pine forest of Inagua, the only area where the species has been naturally present as a regular breeder in the last 25 years. A suitability distribution model using occurrences with demographic relevance (i.e., nest locations of successful breeding attempts analysed using boosted classification trees was built considering orographic, climatic and habitat structure predictors. By means of a standardized survey program we monitored the yearly abundance of the species in 100 sectors since the declaration of Inagua as a Strict Nature Reserve in 1994. Results The variables with the highest relative importance in blue chaffinch habitat preferences were pine height, tree cover, altitude, and rainfall during the driest trimester (July–September. The observed local abundance of the blue chaffinch in Inagua (survey data was significantly correlated with habitat suitability derived from modelling the location of successful nesting attempts (using linear and quantile regressions. The outcomes of the habitat suitability model were used to quantify the suitability of other natural, historic, pine forests of Gran Canaria. Tamadaba is the forest with most suitable woodland patches for the species. We estimated a population size of 195–430 blue chaffinches in Inagua since 2011 (95% CI, the smallest population size of a woodland passerine in the Western Palearctic. Discussion Habitat suitability obtained from modelling the location of successful breeding attempts is a good surrogate of the

Medicinal Plants Density Along an Altitudinal Gradient in and Around Ayubia National Park

International Nuclear Information System (INIS)

Tariq, A.; Adnan, M.; Begum, S.

2016-01-01

Medicinal plants are an essential source of livelihood for many rural populations and are currently facing several threats of extinction in temperate Himalaya, such as excessive grazing and collection along altitudinal gradients. The present study was designed to investigate the species density of medicinal plants at different mid-altitude levels (2200, 2300, 2400, and 2500 m above the sea level (a.s.l.) between two forest-use types and to examine the possible association between medicinal plant densities and forest-stand structural variables along the altitudinal gradient. Factorial design analysis of variance showed that the densities of all medicinal plants differed significantly between the forest-use types (p<0.00) and elevation (p<0.00). Moreover, a significant interaction (p<0.04) was also observed between the forest-use types and elevation. In the old-growth forest, density of medicinal plants was 290/40 m/sup 2/ at the higher altitude (2500 m a.s.l.), approximately 1.5-fold less than the 475/40 m/sup 2/ density observed at lower altitude (2200 m a.s.l.). However, in derived woodland, density of medicinal plants at higher altitude was approximately 4-fold less than that at the lower altitude. At these altitudinal levels, medicinal plants densities, such as Valeriana jatamansi, were significantly higher under old-growth forest compared to derived woodland, where they were almost nonexistent. A rapid vulnerability assessment has also shown that Valeriana jatamansi and Viola canescens were highly vulnerable species. Litter cover was the influential variable that was most likely related to medicinal plant density. In conclusion, abundance of medicinal plants decreased along mid-altitude levels in both of the forest-use types. However, this decrease was extremely marked in the derived woodland, and this decline may be due to human activity. Hence, these factors must be considered in future studies to suggest protective measures that can be applied along

75 FR 71463 - Woodland Mills Corporation Mill Spring, NC; Notice of Revised Determination on Reconsideration

Science.gov (United States)

2010-11-23

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-73,695] Woodland Mills Corporation Mill Spring, NC; Notice of Revised Determination on Reconsideration By application dated July 22... regarding the eligibility of workers and former workers of Woodland Mills Corporation, Mill Spring, North...

At the Crossroads: Does the Configuration of Roadside Vegetation Affect Woodland Bird Communities in Rural Landscapes?

Science.gov (United States)

Hall, Mark; Nimmo, Dale; Bennett, Andrew F.

2016-01-01

In agricultural regions worldwide, linear networks of vegetation such as hedges, fencerows and live fences provide habitat for plant and animal species in heavily modified landscapes. In Australia, networks of remnant native vegetation along roadsides are a distinctive feature of many rural landscapes. Here, we investigated the richness and composition of woodland-dependent bird communities in networks of eucalypt woodland vegetation along roadsides, in an agricultural region in which >80% of native woodland and forest vegetation has been cleared. We stratified sites in a) cross sections and b) linear strips of roadside vegetation, to test the influence on woodland birds of site location and configuration in the linear network (the ‘intersection effect’). We also examined the influence of tree size at the site, the amount of wooded vegetation surrounding the site, and the abundance of an aggressive native species, the noisy miner Manorina melanocephala. Birds were surveyed at 26 pairs of sites (cross section or linear strip) on four occasions. A total of 66 species was recorded, including 35 woodland species. The richness of woodland bird species was influenced by site configuration, with more species present at cross sections, particularly those with larger trees (>30 cm diameter). However, the strongest influence on species richness was the relative abundance of the noisy miner. The richness of woodland birds at sites where noisy miners were abundant was ~20% of that where miners were absent. These results recognise the value of networks of roadside vegetation as habitat for woodland birds in depleted agricultural landscapes; but highlight that this value is not realised for much of this vast vegetation network because of the dominance of the noisy miner. Nevertheless, roadside vegetation is particularly important where the configuration of networks create nodes that facilitate movement. Globally, the protection, conservation and restoration of such linear

At the Crossroads: Does the Configuration of Roadside Vegetation Affect Woodland Bird Communities in Rural Landscapes?

Science.gov (United States)

Hall, Mark; Nimmo, Dale; Bennett, Andrew F

2016-01-01

In agricultural regions worldwide, linear networks of vegetation such as hedges, fencerows and live fences provide habitat for plant and animal species in heavily modified landscapes. In Australia, networks of remnant native vegetation along roadsides are a distinctive feature of many rural landscapes. Here, we investigated the richness and composition of woodland-dependent bird communities in networks of eucalypt woodland vegetation along roadsides, in an agricultural region in which >80% of native woodland and forest vegetation has been cleared. We stratified sites in a) cross sections and b) linear strips of roadside vegetation, to test the influence on woodland birds of site location and configuration in the linear network (the 'intersection effect'). We also examined the influence of tree size at the site, the amount of wooded vegetation surrounding the site, and the abundance of an aggressive native species, the noisy miner Manorina melanocephala. Birds were surveyed at 26 pairs of sites (cross section or linear strip) on four occasions. A total of 66 species was recorded, including 35 woodland species. The richness of woodland bird species was influenced by site configuration, with more species present at cross sections, particularly those with larger trees (>30 cm diameter). However, the strongest influence on species richness was the relative abundance of the noisy miner. The richness of woodland birds at sites where noisy miners were abundant was ~20% of that where miners were absent. These results recognise the value of networks of roadside vegetation as habitat for woodland birds in depleted agricultural landscapes; but highlight that this value is not realised for much of this vast vegetation network because of the dominance of the noisy miner. Nevertheless, roadside vegetation is particularly important where the configuration of networks create nodes that facilitate movement. Globally, the protection, conservation and restoration of such linear

USDA Forest Service National Woodland Owner Survey, 2011-2013: design, implementation, and estimation methods

Science.gov (United States)

Brett J. Butler; Brenton J. Dickinson; Jaketon H. Hewes; Sarah M. Butler; Kyle Andrejczyk; Marla. Markowski-Lindsay

2016-01-01

The National Woodland Owner Survey (NWOS) is conducted by the U.S. Forest Service, Forest Inventory and Analysis program to increase the understanding of the attitudes, behaviors, and demographics of private forest and woodland ownerships across the United States. The information is intended to help policy makers, resource managers, educators, service providers, and...

Shortleaf pine natural community restoration on Peck Ranch Conservation Area in the Missouri Ozarks

Science.gov (United States)

John G. Tuttle; Kim J. Houf

2007-01-01

Oak decline has become a significantly increasing problem on Peck Ranch Conservation Area over the last several years. Most of the oak decline problems exist on past shortleaf pine sites. To address this issue, the area managers wrote a natural community restoration plan for 2,233 acres located on the Current-Eleven Point Oak-Pine Woodland Dissected Plain land type...

Development of broadleaved woodland on colliery and open pit coal mines in the United Kingdom

International Nuclear Information System (INIS)

Humphries, R.N.; McQuire, G.E.

1994-01-01

Broadleaved woodland is an important land use and vegetation type in the United Kingdom (UK), and potentially the most effective landscape and restoration treatment for colliery waste tips and open pit coal sites. A field-based national survey of collieries in England and Wales in 1986 and 1987 showed that establishment was satisfactory in only half of the schemes, and growth was deemed satisfactory in less than one-fifth. There are standard forestry practices whereby stock quality can be assured, and herbaceous vegetation controlled or eliminated by the use of herbicides. During the restoration of the site, depending on choice of species, adequate soil water can be provided by the selection of appropriate soil types and thicknesses, and adoption of appropriate soil handling and decompaction practices. The low affinity of the plantations with local and regional types was partly due to the planting of non-native species and partly due to the failure to match species with site and soil characteristics. There is no reason why woodlands of a local and regional character cannot be established by planting the associated species. A matrix of fast-growing tree and/or shrub species should be used to promote early woodland development. These would be removed during normal management which is essential for the ultimate success of the woodland. Planting schemes should also incorporate woodland structural elements and understory and ground flora species. Provided that these measures are fully implemented, significant improvements in establishment, growth, and woodland development on restored sites should be achieved

Decision-support model to explore the feasibility of using translocation to restore a woodland caribou population in Pukaskwa National Park, Canada

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Emily K. Gonzales

2015-12-01

Full Text Available The distribution and abundance of woodland caribou (Rangifer tarandus caribou have declined dramatically in the past century. Without intervention the most southern population of caribou in eastern North America is expected to disappear within 20 years. Although translocations have reintroduced and reinforced some populations, approximately half of caribou translocation efforts fail. Translocations are resource intensive and risky, and multiple interrelated factors must be considered to assess their potential for success. Structured decision-making tools, such as Bayesian belief networks, provide objective methods to assess different wildlife management scenarios by identifying the key components and relationships in an ecosystem. They can also catalyze dialogue with stakeholders and provide a record of the complex thought processes used in reaching a decision. We developed a Bayesian belief network for a proposed translocation of woodland caribou into a national park on the northeastern coast of Lake Superior, Ontario, Canada. We tested scenarios with favourable (e.g., good physical condition of adult caribou and unfavourable (e.g., high predator densities conditions with low, medium, and high numbers of translocated caribou. Under the current conditions at Pukaskwa National Park, augmenting the caribou population is unlikely to recover the species unless wolf densities remain low (<5.5/1000 km2 or if more than 300 animals could be translocated.

Passerine bird communities of Iberian dehesas: a review

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Tellería, J. L.

2001-01-01

Full Text Available The Iberian dehesas are a man-made habitat composed of scattered oaks (Quercus spp. and extensive grass cover occupying three million ha in south-western Iberia. This paper compares the structure of the passerine bird communities in this region with other bird assemblages of Iberian woodlands. Although forest bird numbers in the southern half of the Iberian peninsula are decreasing, the dehesas show the highest richness in breeding birds, seemingly as the result of the increased presence of border and open-habitat birds. A low intra-habitat turnover of species was observed in the dehesas, with birds recorded at a sampling point accounting for a high percentage of the total richness of the community. This can be related to the low spatial patchiness of this habitat. In winter, the dehesas continued to maintain many bird species, but showed bird densities similar to other woodlands. This pattern, as well as the scarcity of some common forest passerines during the breeding period, could result from the removal of the shrub layer typical of Mediterranean woodlands.

Eddy flux and leaf level measurements of biogeni VOC emissions from Mopane woodland of Botswana

NARCIS (Netherlands)

Greenberg, J.P.; Guenter, A.; Harley, P.; Otter, L.; Veenendaal, E.M.; Hewwit, C.N.; James, A.E.; Owen, S.M.

2003-01-01

Biogenic volatile organic compound (BVOC) emissions were measured in a mopane woodland near Maun, Botswana in January–February 2001 as part of SAFARI 2000. This landscape is comprised of more than 95% of one woody plant species, Colophospermum mopane (Caesalpinaceae). Mopane woodlands extend over a

Aboveground and belowground biomass allocation in native Prosopis caldenia Burkart secondaries woodlands in the semi-arid Argentinean pampas

International Nuclear Information System (INIS)

Risio, Lucia; Herrero, Celia; Bogino, Stella M.; Bravo, Felipe

2014-01-01

The woodlands in the south-west of the Argentinean pampas are dominated by Prosopis Caldenia Burkart (calden). The current deforestation rate of this woodlands is 0.82% per year. Different compensation initiatives have begun that recognize the role of forests as environmental service providers. The financial incentives they offer make it necessary to quantify the amount of carbon stored in the forest biomass. A model for estimating calden biomass was developed. Thirty-eight trees were selected, felled and divided into sections. An equation system was fitted using joint generalized regression to ensure the additivity property. A weighted regression was used to avoid heteroscedasticity. In these woodlands fire is the main disturbance and it can modify tree allometry, due this all models included the area of the base of the stem and tree height as independent variables since it indirectly collects this variability. Total biomass and the stem fraction had the highest R2 A dj. values (0.75), while branches with a diameter less than 7 cm had the lowest (0.58). Tree biomass was also analyzed by partitioning into the basic fractions of stem, crown, roots, and the root/shoot ratio. Biomass allocation was greatest in the crown fraction and the mean root/shoot ratio was 0.58. The carbon stock of the caldenales considering only calden tree biomass is 20.2 Mg ha −1 . While the overall carbon balance of the region is negative (deforestation and biomass burning, the remnant forested area has increased their calden density and in an indirect way his carbon sequestration capacity could also be increased. - Highlights: • A model for estimating aboveground and belowground Prosopis caldenia biomass was developed. • Biomass allocation into the tree and the root/shoot ratio were analyzed. • The equation systems presented had made it possible to more accurately estimate the biomass stored in calden woodlands

Historical mapping reveals causes and temporal patterns of woodland contraction in Austur-Skaftafellssýsla from the 12th century AD to present

Science.gov (United States)

Sigurmundsson, Friðþór S.; Gísladóttir, Guðrún; Erlendsson, Egill; Þorbjarnarson, Höskuldur

2016-04-01

Land-cover changes in Iceland over the last millennium encompass birch (Betula pubescens) woodland depletion and extensive soil erosion. Yet few studies have focused on spatial change of birch woodland coverage in Iceland over centuries and why and how the woodland depletion took place. The main objectives of this study are: (1) to map the woodland distribution today in Austur-Skaftafellssýsla (3041 km2) in southern Iceland; (2) to map woodland holdings over a period of 900 years from eleventh. AD 1100 to the early 20th century; (3) explain the relative impacts of socio-economic and natural forces on woodland cover over this period. We use a combined approach of historical reconstruction from diverse written archives, GIS techniques and field work. The woodland in Austur-Skaftafellssýsla now covers 73.2 km2 (2.5% of the study area). The woodland holdings, 44 in total, are regularly listed in the church inventories from 1179 to 1570 and are owned by the church. In the first complete register for the district in 1641 the woodland holdings were 73, owned and used by 58 estates, and distributed across Austur-Skaftafellssýsla. All the main patches of woodland remain today, with the exception of four minor woodlands which were exhausted near the end of the 19th century. The woodland was used for firewood and charcoal making as well as grazing during the study period but, crucially, in most cases only one estate had authority over each holding, none were commons. The main driving force behind the development of woodlands was socio-economic, rather than natural, where the form of ownership was fundamental for the fate of the woodland. Harsh climate and volcanism were not directly responsible for woodland depletion. The latter half of the 19th century was the period of greatest woodland loss. This period coincides with considerable expansion in livestock numbers, especially sheep and associated all year around grazing, at a time when the Little Ice Age culminated in

Real-Time Mass Spectrometry Monitoring of Oak Wood Toasting: Elucidating Aroma Development Relevant to Oak-aged Wine Quality

Science.gov (United States)

Farrell, Ross R.; Wellinger, Marco; Gloess, Alexia N.; Nichols, David S.; Breadmore, Michael C.; Shellie, Robert A.; Yeretzian, Chahan

2015-11-01

We introduce a real-time method to monitor the evolution of oak aromas during the oak toasting process. French and American oak wood boards were toasted in an oven at three different temperatures, while the process-gas was continuously transferred to the inlet of a proton-transfer-reaction time-of-flight mass spectrometer for online monitoring. Oak wood aroma compounds important for their sensory contribution to oak-aged wine were tentatively identified based on soft ionization and molecular mass. The time-intensity profiles revealed toasting process dynamics illustrating in real-time how different compounds evolve from the oak wood during toasting. Sufficient sensitivity was achieved to observe spikes in volatile concentrations related to cracking phenomena on the oak wood surface. The polysaccharide-derived compounds exhibited similar profiles; whilst for lignin-derived compounds eugenol formation differed from that of vanillin and guaiacol at lower toasting temperatures. Significant generation of oak lactone from precursors was evident at 225 oC. Statistical processing of the real-time aroma data showed similarities and differences between individual oak boards and oak wood sourced from the different origins. This study enriches our understanding of the oak toasting process and demonstrates a new analytical approach for research on wood volatiles.

Ecology and management of a remnant Brachystegia Speciformis (Miombo) Woodland in North Eastern Soutpansberg, Limpopo Province

CSIR Research Space (South Africa)

Saidi, AT

2006-01-01

Full Text Available is the season for re-sprouting. Fresh-brown to pink leaves start to grow. The fruit pods also dry and start to burst open to release the seeds. These seasonal changes are in line with what happens in miombo woodlands elsewhere on the continent. Mafuta (2000...) describes miombo woodlands as deciduous, losing leaves in winter and developing full foliage in summer. Palmer and Pitman (1972), describe similar seasonal changes, and further observe that pink and purple new foliage of miombo woodlands presents a great...

Greenhouse gas emissions from Savanna ( Miombo ) woodlands ...

African Journals Online (AJOL)

Natural vegetation represents an important sink for greenhouse gases (GHGs); however, there is relatively little information available on emissions from southern African savannas. The effects of clearing savanna woodlands for crop production on soil fluxes of N2O, CO2 and CH4 were studied on clay (Chromic luvisol) and ...

Response of bird community structure to habitat management in piñon-juniper woodland-sagebrush ecotones

Science.gov (United States)

Knick, Steven T.; Hanser, Steven E.; Grace, James B.; Hollenbeck, Jeff P.; Leu, Matthias

2017-01-01

Piñon (Pinus spp.) and juniper (Juniperus spp.) woodlands have been expanding their range across the intermountain western United States into landscapes dominated by sagebrush (Artemisia spp.) shrublands. Management actions using prescribed fire and mechanical cutting to reduce woodland cover and control expansion provided opportunities to understand how environmental structure and changes due to these treatments influence bird communities in piñon-juniper systems. We surveyed 43 species of birds and measured vegetation for 1–3 years prior to treatment and 6–7 years post-treatment at 13 locations across Oregon, California, Idaho, Nevada, and Utah. We used structural equation modeling to develop and statistically test our conceptual model that the current bird assembly at a site is structured primarily by the previous bird community with additional drivers from current and surrounding habitat conditions as well as external regional bird dynamics. Treatment reduced woodland cover by >5% at 80 of 378 survey sites. However, habitat change achieved by treatment was highly variable because actual disturbance differed widely in extent and intensity. Biological inertia in the bird community was the strongest single driver; 72% of the variation in the bird assemblage was explained by the community that existed seven years earlier. Greater net reduction in woodlands resulted in slight shifts in the bird community to one having ecotone or shrubland affinities. However, the overall influence of woodland changes from treatment were relatively small and were buffered by other extrinsic factors. Regional bird dynamics did not significantly influence the structure of local bird communities at our sites. Our results suggest that bird communities in piñon-juniper woodlands can be highly stable when management treatments are conducted in areas with more advanced woodland development and at the level of disturbance measured in our study.

Woodland caribou persistence and extirpation in relic populations on Lake Superior

Directory of Open Access Journals (Sweden)

Arthur T. Bergerud

2007-04-01

Full Text Available Extended: The hypothesis was proposed that woodland caribou (Rangifer tarandus caribou in North America had declined due to wolf predation and over-hunting rather than from a shortage of winter lichens (Bergerud, 1974. In 1974, two study areas were selected for testing: for the lichen hypothesis, we selected the Slate Islands in Lake Superior (36 km2, a closed canopy forest without terrestrial lichens, wolves, bears, or moose; for the predation hypothesis, we selected the nearby Pukaskwa National Park (PNP where terrestrial lichens, wolves, bears, and moose were present. Both areas were monitored from 1974 to 2003 (30 years. The living and dead caribou on the Slates were estimated by the ‘King census’ strip transect (mean length 108±9.3 km, extremes 22-190, total 3026 km and the Lincoln Index (mean tagged 45±3.6, extremes 15-78. The mean annual population on the Slate Islands based on the strip transects was 262±22 animals (extremes 104-606, or 7.3/km2 (29 years and from the Lincoln Index 303±64 (extremes 181-482, or 8.4/km2 (23 years. These are the highest densities in North America and have persisted at least since 1949 (56 years. Mountain maple (Acer spicatum interacted with caribou density creating a record in its age structure which corroborates persistence at relatively high density from c. 1930. The mean percentage of calves was 14.8±0.34% (20 years in the fall and 14.1±1.95% (19 years in late winter. The Slate Islands herd was regulated by the density dependent abundance of summer green foods and fall physical condition rather than density independent arboreal lichen availability and snow depths. Two wolves (1 wolf/150 caribou crossed to the islands in 1993-94 and reduced two calf cohorts (3 and 4.9 per cent calves while female adult survival declined from a mean of 82% to 71% and the population declined ≈100 animals. In PNP, caribou/moose/wolf populations were estimated by aerial surveys (in some years assisted by telemetry

Using a State-and-Transition Approach to Manage Endangered Eucalyptus albens (White Box) Woodlands

Science.gov (United States)

Spooner, Peter G.; Allcock, Kimberly G.

2006-11-01

Eucalyptus albens (White Box) woodlands are among the most poorly conserved and threatened communities in Australia. Remnants are under further threat from stock grazing, deteriorating soil conditions, weed invasion, and salinity. There is an urgent need to restore degraded White Box and other woodland ecosystems to improve landscape function. However, there is still a poor understanding of the ecology of degraded woodland ecosystems in fragmented agricultural landscapes, and consequently a lack of precise scientific guidelines to manage these ecosystems in a conservation context. State and Transition Models (STMs) have received a great deal of attention, mainly in rangeland applications, as a suitable framework for understanding the ecology of complex ecosystems and to guide management. We have developed a STM for endangered White Box woodlands and discuss the merits of using this approach for land managers of other endangered ecosystems. An STM approach provides a greater understanding of the range of states, transitions, and thresholds possible in an ecosystem, and provides a summary of processes driving the system. Importantly, our proposed STM could be used to clarify the level of “intactness” of degraded White Box woodland sites, and provide the impetus to manage different states in complementary ways, rather than attempting to restore ecosystems to one pristine stable state. We suggest that this approach has considerable potential to integrate researcher and land manager knowledge, focus future experimental studies, and ultimately serve as a decision support tool in setting realistic and achievable conservation and restoration goals.

Effect of Tree Phenology on LiDAR Measurement of Mediterranean Forest Structure

Directory of Open Access Journals (Sweden)

William Simonson

2018-04-01

Full Text Available Retrieval of forest biophysical properties using airborne LiDAR is known to differ between leaf-on and leaf-off states of deciduous trees, but much less is understood about the within-season effects of leafing phenology. Here, we compare two LiDAR surveys separated by just six weeks in spring, in order to assess whether LiDAR variables were influenced by canopy changes in Mediterranean mixed-oak woodlands at this time of year. Maximum and, to a slightly lesser extent, mean heights were consistently measured, whether for the evergreen cork oak (Quercus suber or semi-deciduous Algerian oak (Q. canariensis woodlands. Estimates of the standard deviation and skewness of height differed more strongly, especially for Algerian oaks which experienced considerable leaf expansion in the time period covered. Our demonstration of which variables are more or less affected by spring-time leafing phenology has important implications for analyses of both canopy and sub-canopy vegetation layers from LiDAR surveys.

Conflicting short and long-term management goals: Fire effects in endangered golden-cheeked warbler (Setophaga chrysoparia) habitat

Science.gov (United States)

Christina M. Andruk; Norma L. Fowler

2015-01-01

Decades of fire suppression have significantly altered the vegetation structure and composition of savannas, woodlands, and forests. The presence of endangered species and other species of conservation concern in these fire-suppressed systems makes re-introducing fire more challenging. In oak-juniper woodlands of central Texas, we are presented with the challenge of re...

A condition metric for Eucalyptus woodland derived from expert evaluations.

Science.gov (United States)

Sinclair, Steve J; Bruce, Matthew J; Griffioen, Peter; Dodd, Amanda; White, Matthew D

2018-02-01

The evaluation of ecosystem quality is important for land-management and land-use planning. Evaluation is unavoidably subjective, and robust metrics must be based on consensus and the structured use of observations. We devised a transparent and repeatable process for building and testing ecosystem metrics based on expert data. We gathered quantitative evaluation data on the quality of hypothetical grassy woodland sites from experts. We used these data to train a model (an ensemble of 30 bagged regression trees) capable of predicting the perceived quality of similar hypothetical woodlands based on a set of 13 site variables as inputs (e.g., cover of shrubs, richness of native forbs). These variables can be measured at any site and the model implemented in a spreadsheet as a metric of woodland quality. We also investigated the number of experts required to produce an opinion data set sufficient for the construction of a metric. The model produced evaluations similar to those provided by experts, as shown by assessing the model's quality scores of expert-evaluated test sites not used to train the model. We applied the metric to 13 woodland conservation reserves and asked managers of these sites to independently evaluate their quality. To assess metric performance, we compared the model's evaluation of site quality with the managers' evaluations through multidimensional scaling. The metric performed relatively well, plotting close to the center of the space defined by the evaluators. Given the method provides data-driven consensus and repeatability, which no single human evaluator can provide, we suggest it is a valuable tool for evaluating ecosystem quality in real-world contexts. We believe our approach is applicable to any ecosystem. © 2017 State of Victoria.

Stand Structure, Productivity and Carbon Sequestration Potential of Oak Dominated Forests in Kumaun Himalaya

OpenAIRE

Bijendra Lal; L.S. Lodhiyal

2016-01-01

Present study deals with stand structure, biomass, productivity and carbon sequestration in oak dominated forests mixed with other broad leaved tree species. The sites of studied forests were located in Nainital region between 29058’ N lat. and 79028’ E long at 1500-2150 m elevation. Tree density of forests ranged from 980-1100 ind.ha-1. Of this, oak trees shared 69-97%. The basal area of trees was 31.81 to 63.93 m2 ha-1. R. arboreum and Q. floribunda shared maximum basal area 16.45 and 16.32...

White Oak Creek watershed: Melton Valley area Remedial Investigation report, at the Oak Ridge National Laboratory, Oak Ridge, Tennessee: Volume 2, Appendixes A and B

International Nuclear Information System (INIS)

1996-11-01

This document contains Appendixes A ''Source Inventory Information for the Subbasins Evaluated for the White Oak Creek Watershed'' and B ''Human Health Risk Assessment for White Oak Creek / Melton Valley Area'' for the remedial investigation report for the White Oak Creek Watershed and Melton Valley Area. Appendix A identifies the waste types and contaminants for each subbasin in addition to the disposal methods. Appendix B identifies potential human health risks and hazards that may result from contaminants present in the different media within Oak Ridge National Laboratory sites

Status of oak seedlings and saplings in the northern United States: implications for sustainability of oak forests

Science.gov (United States)

Chris W. Woodall; Randall S. Morin; Jim R. Steinman; Charles H. Perry

2008-01-01

Oak species are a substantial component of forest ecosystems in a 24-state region spanning the northern U.S. During recent decades, it has been documented that the health of oak forests has been experiencing large-scale decline. To further evaluate the sustainability of oak forests in nearly half the states of the U.S., the current status of oak seedlings and saplings...

Spatio-Temporal Trends of Oak Decline and Mortality under Periodic Regional Drought in the Ozark Highlands of Arkansas and Missouri

Directory of Open Access Journals (Sweden)

Stephen R. Shifley

2012-08-01

Full Text Available At the forest landscape/region level, based on annual Forest Inventory and Analysis plot data from 1999 to 2010, oak decline and mortality trends for major oak species (groups were examined in the Ozark Highlands of Arkansas and Missouri. Oak decline has elevated cumulative mortality of red oak species to between 11 and 15 percent in terms of relative density and basal area of standing dead oak trees, respectively. These values are three to five times higher than for white oak group and non-oak species. Oak decline and associated escalating mortality have occurred primarily in red oak species while the white oak group has maintained a relatively stable mortality rate that is comparable to non-oak species. Cross-correlation analyses indicate that mortality in the red oak group was significantly correlated with the growing season Palmer drought severity index (PDSI and usually lagged two to three years following single drought events. Moreover, based on the past 17 years PDSI data, it appears that the cumulative impacts of drought may last up to 10 years. The Ozark Highlands experienced a severe drought extending from 1998 to 2000 and another milder drought from 2005 to 2006. These drought events triggered the escalation of mortality starting around year 2000. Spatially, high red oak mortality sites (hot spots with proportional basal area mortality > 0.12 initially occurred in the central Ozarks and spread gradually over most of the Ozark Highlands as regional droughts continued. In contrast, sites with elevated white oak and non-oak mortality occurred sporadically, mainly in the southern portion (Arkansas of the Ozark Highlands. During the most recent inventory period (2006–2010, over 60%, 7% and 5% of red oak, white oak and non-oak groups, respectively, had relative mortality rates of > 12%.

Long-term energy balance and vegetation water stress monitoring of Mediterranean oak savanna using satellite thermal data

Science.gov (United States)

González-Dugo, Maria P.; Chen, Xuelong; Andreu, Ana; Carpintero, Elisabet; Gómez-Giraldez, Pedro; Su, Z.(Bob)

2017-04-01

Drought is one of the major hazards faced by natural and cropped vegetation in the Mediterranean Sea Basin. Water scarcity is likely to be worsened under the predicted conditions of climate change, which is expected to make this region both warmer and drier. A Holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs. This ecosystem is considered an example of sustainable land use, supporting a large number of species and diversity of habitats and for its importance in rural economy. A similar ecosystem is worldwide distributed in areas with Mediterranean climate (as California or South Africa) and shares structural and functional properties with tropical savannas in Africa, Australia and South America. Remote sensing time series can assist the monitoring of the energy balance components, with special attention to the evapotranspiration and vegetation water stress over these areas. Long-term data analysis may improve our understanding of the functioning of the system, helping to assess drought impacts and leading to reduce the economic and environmental vulnerability of this ecosystem. This work analyzes the evolution the surface energy balance components, mapping the evapotranspiration and moisture stress of holm oak woodlands of Spain and Portugal during the last 15 years (2001-2015). The surface energy balance model (SEBS) has been applied over the Iberian Peninsula on a monthly time scale and 0.05° spatial resolution, using multi-satellite and meteorological forcing data. Modelled energy and water fluxes have been validated using ground measurements of two eddy covariance towers located in oak savanna sites during 3 years, resulting in moderate deviations from observations (10-25 W/m2). The departure of actual ET from the

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO2 exposure in a subtropical oak woodland

Science.gov (United States)

Hungate, Bruce A; Dijkstra, Paul; Wu, Zhuoting; Duval, Benjamin D; Day, Frank P; Johnson, Dale W; Megonigal, J Patrick; Brown, Alisha L P; Garland, Jay L

2013-01-01

Summary Rising atmospheric carbon dioxide (CO2) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO2. We used open-top chambers to manipulate CO2 during regrowth after fire, and measured C, N and tracer 15N in ecosystem components throughout the experiment. Elevated CO2 increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO2 increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term 15N tracer indicated that CO2 exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO2 on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO2 in current biogeochemical models, where the effect of elevated CO2 on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response. PMID:23718224

Comparative analysis of some bioecological characteristics of Hungarian oak and Turkey oak

Directory of Open Access Journals (Sweden)

Vukin Marina

2013-01-01

Full Text Available This paper gives an in-depth study of some bioecological characteristics of the Hungarian and Turkey oak, autochthonous oak species and edificators of climatogenic communities of central Serbia. Today, these forest complexes are mostly of coppice origin and as such, they require implementation of reclamation operations. In order to determine biological dominance, select the optimal reclamation operations and finally improve the state of these forests, we studied the environmental conditions, stand state, development and position of individual trees in a mixed coppice stand of Hungarian and Turkey oak in a suburban zone of the city of Belgrade.

Determining the Impact of Forest Mortality in Semi-Arid Woodlands on Local and Regional Carbon Dynamics

Energy Technology Data Exchange (ETDEWEB)

Litvak, Marcy [University of New Mexico

2018-04-09

We received funds in July 2012, and with supplemental funds, this funding ended in July 2017. Our overall project goals were to quantify the consequences of pinon mortality for carbon, water and energy exchange in pinon-juniper woodlands. To do this, we have been continuously measuring carbon, water and energy exchange using eddy covariance, over two pinon-juniper woodlands in central New Mexico. In one site, we girdled 1632 trees in the 4 ha surrounding the tower in Sept 2009. The other site, only 5 km away on the same plateau, was left intact, to serve as a control. We used this paired tower approach so we could directly evaluate the differences between how fluxes from disturbed and intact woodlands respond to the exact same climate conditions. In addition to eddy covariance measured fluxes from the two woodlands, we also made sap flux measurements, biomass, gas exchange, and soil respiration fluxes simultaneously in the two sites. The overall objective of this proposal is to measure the carbon and climate forcing consequences of widespread coniferous mortality events in the Southwestern US. We will incorporate these findings into a land surface model to understand the long term carbon dynamics of these mortality events and use remote sensing maps of mortality in PJ woodlands in NM to scale the implications of these events to regional carbon dynamics and atmospheric CO2. In 2013, our control PJ woodland experienced a natural pinon mortality event as bark beetles invaded the area. We received supplemental funds to quantify the extent of the mortality and how it progresses, and to add remotely sensed imagery to aid in this and estimate the loss of biomass at the site due to mortality. Finally, we have been exploring the use of both CLM and SIPNET to analyze how well these models to in representing how these woodlands change following pinon mortality. Here, I present the results of what we have learned in these areas: 1) how carbon, water and energy fluxes, have

The historical significance of oak

Science.gov (United States)

J. V. Thirgood

1971-01-01

A brief history of the importance of oak in Europe, contrasting the methods used in France and Britain to propagate the species and manage the forests for continued productivity. The significance of oak as a strategic resource during the sailing-ship era is stressed, and mention is made of the early development of oak management in North America. The international...

Propagation of Southern Red Oak and Water Oak by Rooted Cuttings

Science.gov (United States)

Horace J. Duncan; Fred R. Matthews

1969-01-01

Southern red oak and water oak, needed in studies of fusiform rust of southern pines, were propagated from cuttings of rooted stump sprouts and mature tree branches placed in outdoor propagation beds in June. Root strike and root development were increased when cuttings with basal wounds were treated with both the hormone IBA and the fungicide folpet. Cuttings from...

77 FR 33560 - Woodland Rail, LLC-Acquisition and Operation Exemption-Line of Maine Central Railroad Co.

Science.gov (United States)

2012-06-06

... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35628] Woodland Rail, LLC... United States. The end points of the Line are at engineering station 64+17 in Baileyville and engineering... Woodland Junction, Me., which is engineering station 363+45, and engineering station 393+37, and another...

Socia preferences to Mopane woodland management options: A ...

African Journals Online (AJOL)

Socia preferences to Mopane woodland management options: A case study from Southern Zimbabwe. TA Gondo, C Musvoto, T Mujawo. Abstract. No Abstract. Discovery and Innovation Vol. 19 (1&2) 2007: pp.4-14. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Genetic restoration in the eastern collared lizard under prescribed woodland burning.

Science.gov (United States)

Neuwald, Jennifer L; Templeton, Alan R

2013-07-01

Eastern collared lizards of the Ozarks live in glades--open, rocky habitats embedded in a woodland matrix. Past fire suppression had made the woodlands a barrier to dispersal, leading to habitat destruction, fragmentation and local extinction. Reintroduced populations of lizards were subjected to 10 years of habitat fragmentation under continued fire suppression followed by twelve years of landscape restoration with prescribed burns. Prior to prescribed burning, genetic diversity decreased within glades and differentiation increased among glades. With woodland burning, genetic diversity within glades first decreased during an expanding colonization phase, but then increased as a dynamically stable metapopulation was established. Population differentiation among glades also stabilized in the metapopulation under weak isolation-by-distance. This study is one of the first to examine the genetic changes in a species of conservation concern throughout all the stages of decline and recovery and shows the importance of landscape-level restoration for maintaining the genetic integrity of populations. This study also demonstrates how mark-recapture and genetic data together can yield detailed insight into metapopulation dynamics that would be impossible from just one type of data alone. © 2013 John Wiley & Sons Ltd.

Effects of deer exclosures on oak regeneration in closed-canopy stands

Science.gov (United States)

Angela M. Yuska; Kim C. Steiner; James C. Finley

2008-01-01

Studies of the effects of high deer densities on forest regeneration have shown altered species composition and reduced diversity in stands regenerating after harvest. The effects of browsing in fully stocked, undisturbed stands are less well known but important, as establishment of seedlings of oaks and other species prior to disturbance is very important for self-...

Laurels for Laurel Oaks

Science.gov (United States)

Sisson, Ray

1976-01-01

Describes a former Air Force base converted into a joint school district vocational school which includes among other things an up-to-date facility for the students, located at Laurel Oaks, one of the four campuses of the Great Oaks Joint Vocational School District. (HF)

The Hibernation of the oak Mildew

NARCIS (Netherlands)

Kerling, L.C.P.

1966-01-01

The oak mildew invaded Western Europa in the years 1908 and 1909. Since then this parasite, Microsphaera alphitoides Griff. & Maubl. (syn. M. quercina (Schw.) Burr.) has occurred regularly in the Netherlands on oak seedlings and oak coppice, mainly Quercus pedunculata Ehr. (syn. Q. robur L. ). After

Quercus kelloggii Newb., California black oak

Science.gov (United States)

P.M. McDonald

1990-01-01

California black oak (Quercus kelloggii) exceeds all other California oaks in volume, distribution, and altitudinal range. Yet this deciduous hardwood has had little sustained commercial use and almost no management, even though its wood closely resembles that of its valuable, managed, and heavily used counterpart-northern red oak (...

Structure of herbivore communities in two oak (Quercus spp.) hybrid zones.

Science.gov (United States)

Boecklen, William J; Spellenberg, Richard

1990-11-01

We examined patterns of density and species diversity for leaf-mining Lepidopterans and gall-forming Hymenopterans in two oak (Quercus spp.) hybrid zones: Quercus depressipes x Q. rugosa and Q. emoryi x Q. coccolobifolia. In both species complexes, hybrid hosts typically supported significantly lower densities and species diversity of parasites than did parental types. This contradicts the findings of Whitham (1989) that suggested that hybrid hosts may act as parasite sinks both in ecological and evolutionary time. We discuss features of hybrid zones that are likely to influence patterns of herbivory.

Evaluating lidar point densities for effective estimation of aboveground biomass

Science.gov (United States)

Wu, Zhuoting; Dye, Dennis G.; Stoker, Jason M.; Vogel, John M.; Velasco, Miguel G.; Middleton, Barry R.

2016-01-01

The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) was recently established to provide airborne lidar data coverage on a national scale. As part of a broader research effort of the USGS to develop an effective remote sensing-based methodology for the creation of an operational biomass Essential Climate Variable (Biomass ECV) data product, we evaluated the performance of airborne lidar data at various pulse densities against Landsat 8 satellite imagery in estimating above ground biomass for forests and woodlands in a study area in east-central Arizona, U.S. High point density airborne lidar data, were randomly sampled to produce five lidar datasets with reduced densities ranging from 0.5 to 8 point(s)/m2, corresponding to the point density range of 3DEP to provide national lidar coverage over time. Lidar-derived aboveground biomass estimate errors showed an overall decreasing trend as lidar point density increased from 0.5 to 8 points/m2. Landsat 8-based aboveground biomass estimates produced errors larger than the lowest lidar point density of 0.5 point/m2, and therefore Landsat 8 observations alone were ineffective relative to airborne lidar for generating a Biomass ECV product, at least for the forest and woodland vegetation types of the Southwestern U.S. While a national Biomass ECV product with optimal accuracy could potentially be achieved with 3DEP data at 8 points/m2, our results indicate that even lower density lidar data could be sufficient to provide a national Biomass ECV product with accuracies significantly higher than that from Landsat observations alone.

Population ecology of two woodland caribou herds in the southern Yukon

Directory of Open Access Journals (Sweden)

Richard Farnell

1996-01-01

Full Text Available Since the mid 1980's, the Aishihik herd of woodland caribou (Rangifer tarandus caribou declined from approximately 1500 to 583 animals. During the same period a nearby herd, the Wolf Lake Herd increased from approximately 664 to 1249 animals. This paper compares aspects of the ecology of these two herds to determine how these relationships conform to a general model of caribou population ecology described by Seip (1992. Comparisons include caribou demographic characteristics and distribution patterns, predator densities, abundance of alternate prey, human hunting and snow depth on caribou winter range. Ecological differences between herds were apparent in the ratio of prime bulls to cows, the abundance of moose (Alces alces, the occurrence of coyotes (Canis latrans, late winter snow conditions, and access to hunting. We hypothesize that the Wolf Lake herd was able to grow because wolves {Canis lupus preyed mainly on the relatively abundant moose population. A highly clumped winter caribou distribution may have further reduced the impact of wolf predation on the Wolf Lake herd. In contrast, the decline of the Aishihik herd was accompanied by a relative scarcity of moose, few prime aged caribou bulls probably due to a more liberal trophy harvest, and wider late-winter dispersion that offered wolves greater access to caribou. The decline may have been exaggerated by the peak in the snowshoe hare (Lepus americanus cycle which may have temporarily improved wolf pup survival. We suspect that moose are normally the primary prey of wolves in the Yukon and that a decline in moose eventually results in their being too scarce to offer an economical prey choice, prompting a prey switch to caribou. Results of our analyses conform incompletely to Seip's (1992 model for woodland caribou population ecology, particularly because the Wolf Lake herd prospered where moose were relatively abundant.

Screening of contaminants in Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Blaylock, B.G.; Frank, M.L.; Hoffman, F.O.; Hook, L.A.; Suter, G.W.; Watts, J.A.

1992-07-01

Waste Area Grouping 2 (WAG 2) of the Oak Ridge National Laboratory (ORNL) is located in the White Oak Creek Watershed and is composed of White Oak Creek Embayment, White Oak Lake and associated floodplain, and portions of White Oak Creek (WOC) and Melton Branch downstream of ORNL facilities. Contaminants leaving other ORNL WAGs in the WOC watershed pass through WAG 2 before entering the Clinch River. Health and ecological risk screening analyses were conducted on contaminants in WAG 2 to determine which contaminants were of concern and would require immediate consideration for remedial action and which contaminants could be assigned a low priority or further study. For screening purposes, WAG 2 was divided into four geographic reaches: Reach 1, a portion of WOC; Reach 2, Melton Branch; Reach 3, White Oak Lake and the floodplain area to the weirs on WOC and Melton Branch; and Reach 4, the White Oak Creek Embayment, for which an independent screening analysis has been completed. Screening analyses were conducted using data bases compiled from existing data on carcinogenic and noncarcinogenic contaminants, which included organics, inorganics, and radionuclides. Contaminants for which at least one ample had a concentration above the level of detection were placed in a detectable contaminants data base. Those contaminants for which all samples were below the level of detection were placed in a nondetectable contaminants data base

Volume and Aboveground Biomass Models for Dry Miombo Woodland in Tanzania

Directory of Open Access Journals (Sweden)

Ezekiel Edward Mwakalukwa

2014-01-01

Full Text Available Tools to accurately estimate tree volume and biomass are scarce for most forest types in East Africa, including Tanzania. Based on a sample of 142 trees and 57 shrubs from a 6,065 ha area of dry miombo woodland in Iringa rural district in Tanzania, regression models were developed for volume and biomass of three important species, Brachystegia spiciformis Benth. (n = 40, Combretum molle G. Don (n = 41, and Dalbergia arbutifolia Baker (n = 37 separately, and for broader samples of trees (28 species, n = 72, shrubs (16 species, n = 32, and trees and shrubs combined (44 species, n = 104. Applied independent variables were log-transformed diameter, height, and wood basic density, and in each case a range of different models were tested. The general tendency among the final models is that the fit improved when height and wood basic density were included. Also the precision and accuracy of the predictions tended to increase from general to species-specific models. Except for a few volume and biomass models developed for shrubs, all models had R2 values of 96–99%. Thus, the models appear robust and should be applicable to forests with similar site conditions, species, and diameter ranges.

Prescribed burning in mid and late successional juniper woodlands

Science.gov (United States)

Western juniper woodlands of the western United States have expanded rapidly since settlement in the late 1800’s. To recover shrub steppe and other plant communities requires that invasive junipers be controlled. We have evaluated recovery of several plant associations after combinations of junipe...

Woodland caribou management in Alberta: historical perspectives and future opportunities

Directory of Open Access Journals (Sweden)

Elston H. Dzus

2007-04-01

Full Text Available Woodland caribou conservation has been the topic of much debate for the past few decades. By the late 1970s there was growing concern about declining woodland caribou populations and the interaction between industrial activities and woodland caribou. Initial concerns led to the closure of the licensed hunting season in 1981. Early confrontation between government and industry in the late 1980s transformed into a series of evolving collaborative ventures. Improving our understanding of the basic ecology of woodland caribou in Alberta was at the center of early research efforts; more recent studies have examined the effects of industrial activities on caribou and effectiveness of various mitigation factors. Despite having amassed an impressive body of information from a research and monitoring perspective, progress on implementing effective management actions has been less dramatic. Industry has endured significant costs implementing a variety of perceived conservation initiatives, but caribou populations continued to decline through the last few decades. While some parties feel more research is needed, there is growing consensus that changes to habitat as induced by human activities are important factors influencing current caribou declines. Predation is a proximate cause of most caribou mortality. Climate change mediated alterations to habitat and predator-prey interactions remain a key source of uncertainty relative to future caribou population trends. Management actions will need to deal with long term habitat changes associated with human land use and short term implications of increased predation. In 2005, the provincial minister responsible for caribou conservation responded to the draft 2004 recovery plan and created the Alberta Caribou Committee (ACC. The goal of the ACC is to maintain and recover woodland caribou in Alberta’s forest ecosystems while providing opportunities for resource development, following guidance provided by the

Engaging with peri-urban woodlands in England: the contribution to people's health and well-being and implications for future management.

Science.gov (United States)

O'Brien, Liz; Morris, Jake; Stewart, Amy

2014-06-12

In this paper we engage with debates concerning people and their contact with the natural environment as part of everyday life drawing on Irwin's ideas of co-construction and Gibson's theory of affordances. We focus on peri-urban woodlands in England as important places where people can interact with nature for health and well-being. Qualitative data were collected in situ via walks in the woods, focus group discussions and photo elicitation, with a sample of 49 people. These methods provide rich data on the wide range of meanings associated with woodlands that can have a perceived impact on people's health and well-being. The findings link to contemporary debates about health, well-being and ecosystem services. We explore the inter-play between attributes of the physical environment and the range of facilities provided to enable access, social interactions and the benefits people attribute to their woodland experiences. We conclude that peri-urban woodlands can clearly contribute to self-reported health and well-being in multiple ways, and that organized activities can be important for those who face barriers to accessing woodlands. A strong message emerging from the research is the opportunity afforded by woodlands for social connections with others, as well as the provision of a range of sensory benefits and opportunities to observe and enjoy seasonal change in woodlands. Mental restoration via connection with nature also emerged as important, confirming previous research.

Reconstituted products from oak

Science.gov (United States)

W. C. Lewis; B. G. Heebink

1971-01-01

"Reconstituted" describes a family of panel products made from fractionated oak, bonded with either a synthetic resin or a natural lignin bond. Several current commercial fiber panel products from oak are described, and the status of research on experimental products and processes is presented. Recent technological developments are removing the stigma...

Microgravity survey of the Oak Ridge K-25 Site, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Kaufmann, R.D.

1996-05-01

Karst features are known to exist within the carbonate bedrock of the Oak Ridge K-25 Site and may play an important role in groundwater flow and contaminant migration. This report discusses the results of a microgravity survey of the Oak Ridge K-25 Site. The main objective of the survey is to identify areas containing bedrock cavities. Secondary objectives included correlating the observed gravity to the geology and to variations in overburden thickness. The analysis includes 11 profile lines that are oriented perpendicular to the geologic strike and major structures throughout the K-25 Site. The profile lines are modeled in an effort to relate gravity anomalies to karst features such as concentrations of mud-filled cavities. Regolith thickness and density data provided by boreholes constrain the models. Areally distributed points are added to the profile lines to produce a gravity contour map of the site. In addition, data from the K-901 area are combined with data from previous surveys to produce a high resolution map of that site. The K-25 Site is located in an area of folded and faulted sedimentary rocks within the Appalachian Valley and Ridge physiographic province. Paleozoic age rocks of the Rome Formation, Knox Group, and Chickamauga Supergroup underlie the K-25 Site and contain structures that include the Whiteoak Mountain Fault, the K-25 Fault, a syncline, and an anticline. The mapped locations of the rock units and complex structures are currently derived from outcrop and well log analysis

How to identify and manage oak wilt in Texas

Science.gov (United States)

D.N. Appel; R.S. Cameron; A.D. Wilson; J.D. Johnson

2008-01-01

Transporting unseasoned firewood from diseased red oaks is a potential means of spreading the oak wilt fungus. Oak wilt cannot be transmitted by burning infected firewood, but fungal mats may form on firewood in storage. Presently, no vectors have been proven to transmit the fungus from live oaks to other oak trees, but diseased wood fromany oak species should never be...

Regenerating oaks with the shelterwood system

Science.gov (United States)

Ivan L. Sander

1979-01-01

It is well known that a new reproduction stand that follows complete overstory removal will contain oaks in proportion to the numbers and size of advance oak reproduction present before the overstory was removed. Furthermore, the individual advance oaks must be relatively large with well-established root systems before they will compete successfully and be dominant in...

Sudden Oak Death - Eastern (Pest Alert)

Science.gov (United States)

Joseph O' Brien; Manfred Mielke; Steve Oak; Bruce Moltzan

2002-01-01

A phenomenon known as Sudden Oak Death was first reported in 1995 in central coastal California. Since then, tens of thousands of tanoaks (Lithocarpus densiflorus), coast live oaks (Quercus agrifolia), and California black oaks (Quercus kelloggii) have been killed by a newly identified fungus, Phytophthora ramorum. On these hosts, the fungus causes a bleeding canker on...

Phytoecological study of Tetraclinis articulata in the woodland of ...

African Journals Online (AJOL)

The Mediterranean flora is definitely considered as an exceptional diversity that deserves particular attention to be conserved. This work aims to quantify the floristic diversity of Tetraclinis articulata of Beni Affane located at the woodland of Sdamas Chergui (Tiaret, Algeria). The factorial analysis of correspondences allowed ...

The colonisation of woodland gaps by ferns and horsetails

NARCIS (Netherlands)

Bremer, P.

2010-01-01

In the Voorsterbos, a planted woodland on a former sea-floor (the Netherlands), artificial gaps within stands of Fagus sylvatica on boulder clay were monitored for five or six years after cutting. Ten fern species and three species of horsetail established in these gaps, with Dryopteris cristata,

Poison ivy - oak - sumac rash

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/000027.htm Poison ivy - oak - sumac rash To use the sharing features on this page, please enable JavaScript. Poison ivy, oak, and sumac are plants that commonly ...

Mapping and estimating the total living biomass and carbon in low-biomass woodlands using Landsat 8 CDR data

Directory of Open Access Journals (Sweden)

Belachew Gizachew

2016-06-01

Full Text Available Abstract Background A functional forest carbon measuring, reporting and verification (MRV system to support climate change mitigation policies, such as REDD+, requires estimates of forest biomass carbon, as an input to estimate emissions. A combination of field inventory and remote sensing is expected to provide those data. By linking Landsat 8 and forest inventory data, we (1 developed linear mixed effects models for total living biomass (TLB estimation as a function of spectral variables, (2 developed a 30 m resolution map of the total living carbon (TLC, and (3 estimated the total TLB stock of the study area. Inventory data consisted of tree measurements from 500 plots in 63 clusters in a 15,700 km2 study area, in miombo woodlands of Tanzania. The Landsat 8 data comprised two climate data record images covering the inventory area. Results We found a linear relationship between TLB and Landsat 8 derived spectral variables, and there was no clear evidence of spectral data saturation at higher biomass values. The root-mean-square error of the values predicted by the linear model linking the TLB and the normalized difference vegetation index (NDVI is equal to 44 t/ha (49 % of the mean value. The estimated TLB for the study area was 140 Mt, with a mean TLB density of 81 t/ha, and a 95 % confidence interval of 74–88 t/ha. We mapped the distribution of TLC of the study area using the TLB model, where TLC was estimated at 47 % of TLB. Conclusion The low biomass in the miombo woodlands, and the absence of a spectral data saturation problem suggested that Landsat 8 derived NDVI is suitable auxiliary information for carbon monitoring in the context of REDD+, for low-biomass, open-canopy woodlands.

Woodland carbon code: building an evidence base for the "4 per mil" initiative in land converted to forestry.

Science.gov (United States)

Hannam, Jacqueline; Vanguelova, Elena; West, Vicky

2017-04-01

The Woodland Carbon Code is a voluntary standard for woodland creation projects in the UK. Carbon sequestration resulting from certified projects will contribute directly to the UK's national targets for reducing emissions of greenhouse gases (GHG). Whilst this is concerned primarily with above ground capture there is little empirical evidence of the longer term carbon sequestration potential of soils under this land use change in the UK. We present preliminary results from a resurvey of 20 sites originally sampled as part of the soil survey of England and Wales. It includes soil carbon stocks assessed within the soil profile (up to 1m depth) where sites have been converted to forestry in the last 40 years. The small number of sites (n=20) and high variability in soil type, forest type and original land use prevented detailed analysis between these different factors, but overall there was an increase in carbon concentration in the whole profile, driven primarily by an increase the surface organic layers. For all sites combined there was no significant difference in the C stocks between the two survey periods. The increase in carbon stock in the surface organic horizons tended to be offset by a decrease in the mineral subsoils (specifically in Brown Earth soils) primarily as a result of bulk density changes. There are presently insufficient measured data from a range of UK climate, land-use and soil type conditions to quantify with confidence soil C changes during afforestation. This is partly because of the difficulties of detecting relatively slow changes in spatially heterogeneous soils and also obtaining good examples of sites that have undergone documented land use change. Reviewing results from all ongoing afforestation projects in the UK will provide better quantification of the C sequestration potential of forest soils to be accounted for in the Woodland Carbon Code's overall GHG mitigation potential.

Four millennia of woodland structure and dynamics at the Arctic treeline of eastern Canada.

Science.gov (United States)

Auger, Sarah; Payette, Serge

2010-05-01

Paleoecological analysis using complementary indicators of vegetation and soil can provide spatially explicit information on ecological processes influencing trajectories of long-term ecosystem change. Here we document the structure and dynamics of an old-growth woodland before and after its inception 1000 years ago. We infer vegetation and soil characteristics from size and age distributions of black spruce (Picea mariana (Mill.) B.S.P.), soil properties, plant fossils, and paleosols. Radiocarbon ages of charcoal on the ground and in the soil indicate that the fire return interval was approximately 300 years between 2750 and 1000 cal. yr BP. No fire evidence was found before and after this period despite the presence of spruce since 4200 cal. yr BP. The size structures of living and dead spruce suggest that the woodland is in equilibrium with present climate in absence of fire. Tree establishment and mortality occurred regularly since the last fire event around 950 cal. yr BP. Both layering and occasional seeding have contributed to stabilize the spatial distribution of spruce over the past 1000 years. Since initial afforestation, soil development has been homogenized by the changing spatial distribution of spruce following each fire. We conclude that the history of the woodland is characterized by vegetation shifts associated with fire and soil disturbances and by millennial-scale maintenance of the woodland's structure despite changing climatic conditions.

Avian response to pine restoration at Peck Ranch Conservation Area

Science.gov (United States)

Richard Clawson; Carrie Steen; Kim Houf; Terry Thompson

2007-01-01

Midco Pine Flats is a 2,223-acre region of Peck Ranch Conservation Area (CA) that is classified as a pine-oak plains land type association. Extensive logging in the early 1900s removed most overstory shortleaf pine allowing oak to become the primary overstory component. In 2000, Missouri Department of Conservation staff initiated a pineoak woodland restoration project...

Canopy, snow, and lichens on woodland caribou range in southeastern Manitoba

Directory of Open Access Journals (Sweden)

James A. Schaefer

1996-01-01

Full Text Available I examined the relationships among snow cover (api, lichen abundance, and canopy composition on the range of the Aikens Lake population of woodland caribou (Rangifer tarandus caribou in southeastern Manitoba. Percent cover of forage lichens (Cladina spp. was positively correlated with maximum total thickness and with maximum vertical hardness of api. Mixed communities of trembling aspen (Populus tremuloides, spruce (Picea spp., and balsam fir (Abies balsamea showed the most favourable nival conditions for caribou but had low lichen abundance; those dominated by jack pine (Pinus banksiana were the converse. The results suggest an energetic compromise for woodland caribou when foraging for terrestrial lichens. During winter, caribou exhibited significant selection for jack pine communities whereas mixed communities were avoided.

A National Perspective on Women Owning Woodlands (WOW) Networks

Science.gov (United States)

Huff, Emily S.

2017-01-01

This article provides a national overview of women owning woodlands (WOW) networks and the barriers and successes they encounter. Qualitative interview data with key network leaders were used for increasing understanding of how these networks operate. Network leaders were all connected professionally, and all successful WOW networks involved…

Effects of thinning, burning, seeding, and slash arrangements on understory communities in pinyon-juniper woodlands of northern Arizona

Directory of Open Access Journals (Sweden)

Maria Irwin

2011-11-01

Full Text Available Pinyon-juniper woodlands are a dominant ecosystem in the American Southwest that have been increasing in density over the last century, generating concerns about the effects on wildlife habitat, livestock forage, and wildfire risk. We tested 16 treatment combinations designed to restore stands to historic conditions by examining the impact on understory plant richness and abundance. We thinned three sites comprised of different parent soil materials: limestone, sandstone, and basalt. Each site had one of four slash arrangements: piled, broadcast, clustered, or no thinning. Each of these arrangements received a different burning/seeding treatment: prescribed fire, seeding, prescribed fire and seeding, or none. This study corresponded with the driest period in the last 55 years, and plant species richness decreased by an average of 40% from the previous year in the control plots. Richness was significantly different due to slash arrangement at the basalt site only. Burning or seeding did not affect richness at any of the sites. Plant species abundance was generally low and not influenced by treatment or site. This study demonstrates that extensive ecosystem manipulation in the pinyon-juniper woodlands of northern Arizona did not affect understory richness or abundance the first year after treatment during a drought.

Effects of thinning, burning, seeding, and slash arrangements on understory communities in pinyon-juniper woodlands of northern Arizona

Directory of Open Access Journals (Sweden)

Maria R. Irwin

2011-06-01

Full Text Available Pinyon-juniper woodlands are a dominant ecosystem in the American Southwest that have been increasing in density over the last century, generating concerns about the effects on wildlife habitat, livestock forage, and wildfire risk. We tested 16 treatment combinations designed to restore stands to historic conditions by examining the impact on understory plant richness and abundance. We thinned three sites comprised of different parent soil materials: limestone, sandstone, and basalt. Each site had one of four slash arrangements: piled, broadcast, clustered, or no thinning. Each of these arrangements received a different burning/seeding treatment: prescribed fire, seeding, prescribed fire and seeding, or none. This study corresponded with the driest period in the last 55 years, and plant species richness decreased by an average of 40% from the previous year in the control plots. Richness was significantly different due to slash arrangement at the basalt site only. Burning or seeding did not affect richness at any of the sites. Plant species abundance was generally low and not influenced by treatment or site. This study demonstrates that extensive ecosystem manipulation in the pinyon-juniper woodlands of northern Arizona did not affect understory richness or abundance the first year after treatment during a drought.

Coast live oak, Quercus agrifolia, susceptibility and response to goldspotted oak borer, Agrilus auroguttatus, injury in southern California

Science.gov (United States)

Tom W. Coleman; Nancy E. Grulke; Miles Daly; Cesar Godinez; Susan L. Schilling; Philip J. Riggan; Steven J. Seybold

2011-01-01

Oak mortality is often associated with a complex of decline factors. We describe the morphological and physiological responses of coast live oak, Quercus agrifolia Née, in California to an invasive insect, the goldspotted oak borer (GSOB), Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), and evaluate drought as a...

Grid-trapping of the wood mouse (Apodemus sylvaticus in a mediterranean oak-wood (Sicily / Analisi del popolamento di topo selvatico (Apodemus sylvaticus in un querceto mediterraneo (Sicilia

Directory of Open Access Journals (Sweden)

Maurizio Sarà

1993-06-01

Full Text Available Abstract A grid-trapping (CMR Method of the Wood Mouse (A. sylvaticus resident population was carried on three sample areas in a Mediterranean Oak-wood (Bosco della Ficuzza, Palermo. Fifty live traps were settled on a 0.5 ha grid at each sample area and permitted to calculate the Petersen-Lincoln Index (modified by Chapman. The relative density in the typical oak-wooded area (20.4/ha is highest than in the ecotonal and gazed sample area (12.6/ha. Analysis of ground permanence shows that the population in the wooded area is more dinamic than in the other area; in the former area a large number of new captures occurs, in fact, each month and the monthly variation of the relative density has a different trend. These results would confirm the indirect data coming from pellets analysis showing how in Sicily the highest densities occur in woodlands (oak-woods, as well as beech forests. The ecological niche of the Wood Mouse, due also to the apparent lack of A. flavicollis, is thus larger than in peninsular Italy and continental Europe. The reproductive season lasts over the whole year but the birth peaks occurred in summer (1988 and late fall (1989. Population each year stabilizes for overwintering and later (Jun-Nov is almost completely renowed. Moreover, differences in sex and age trappability in relation to the two mode1 of traps utilized and a low mortality due to the cautions in handling the trapped mice, were recorded. Riassunto Allo scopo di evidenziare le differenze tra i popolamenti di Apodemus sylvaticus (Linnaeus, 1758 in relazione all'habitat, sono state effettuate in una tipica querceta mediterranea (Bosco della Ficuzza, PA griglie di trappolamento in tre aree campione, ciascuna con differenti caratteristiche ambientali e morfologiche. Il campionamento, che si è protratto per circa due anni, è stato condotto con il metodo CMR (cattura-marcaggio-ricattura. I risultati ottenuti

Engaging with Peri-Urban Woodlands in England: The Contribution to People’s Health and Well-Being and Implications for Future Management

Science.gov (United States)

O’Brien, Liz; Morris, Jake; Stewart, Amy

2014-01-01

In this paper we engage with debates concerning people and their contact with the natural environment as part of everyday life drawing on Irwin’s ideas of co-construction and Gibson’s theory of affordances. We focus on peri-urban woodlands in England as important places where people can interact with nature for health and well-being. Qualitative data were collected in situ via walks in the woods, focus group discussions and photo elicitation, with a sample of 49 people. These methods provide rich data on the wide range of meanings associated with woodlands that can have a perceived impact on people’s health and well-being. The findings link to contemporary debates about health, well-being and ecosystem services. We explore the inter-play between attributes of the physical environment and the range of facilities provided to enable access, social interactions and the benefits people attribute to their woodland experiences. We conclude that peri-urban woodlands can clearly contribute to self-reported health and well-being in multiple ways, and that organized activities can be important for those who face barriers to accessing woodlands. A strong message emerging from the research is the opportunity afforded by woodlands for social connections with others, as well as the provision of a range of sensory benefits and opportunities to observe and enjoy seasonal change in woodlands. Mental restoration via connection with nature also emerged as important, confirming previous research. PMID:24927035

Engaging with Peri-Urban Woodlands in England: The Contribution to People’s Health and Well-Being and Implications for Future Management

Directory of Open Access Journals (Sweden)

Liz O'Brien

2014-06-01

Full Text Available In this paper we engage with debates concerning people and their contact with the natural environment as part of everyday life drawing on Irwin’s ideas of co-construction and Gibson’s theory of affordances. We focus on peri-urban woodlands in England as important places where people can interact with nature for health and well-being. Qualitative data were collected in situ via walks in the woods, focus group discussions and photo elicitation, with a sample of 49 people. These methods provide rich data on the wide range of meanings associated with woodlands that can have a perceived impact on people’s health and well-being. The findings link to contemporary debates about health, well-being and ecosystem services. We explore the inter-play between attributes of the physical environment and the range of facilities provided to enable access, social interactions and the benefits people attribute to their woodland experiences. We conclude that peri-urban woodlands can clearly contribute to self-reported health and well-being in multiple ways, and that organized activities can be important for those who face barriers to accessing woodlands. A strong message emerging from the research is the opportunity afforded by woodlands for social connections with others, as well as the provision of a range of sensory benefits and opportunities to observe and enjoy seasonal change in woodlands. Mental restoration via connection with nature also emerged as important, confirming previous research.

White Oak Creek Watershed: Melton Valley Area Remedial Investigation Report, Oak Ridge National Laboratory, Oak Ridge, Tennessee: Volume 3 Appendix C

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

This report provides details on the baseline ecological risk assessment conducted in support of the Remedial Investigation (RI) Report for the Melton Valley areas of the White Oak Creek watershed (WOCW). The RI presents an analysis meant to enable the US Department of Energy (DOE) to pursue a series of remedial actions resulting in site cleanup and stabilization. The ecological risk assessment builds off of the WOCW screening ecological risk assessment. All information available for contaminated sites under the jurisdiction of the US Department of Energy`s Comprehensive Environmental Response, Compensation, and Liability Act Federal Facilities Agreement within the White Oak Creek (WOC) RI area has been used to identify areas of potential concern with respect to the presence of contamination posing a potential risk to ecological receptors within the Melton Valley area of the White Oak Creek watershed. The risk assessment report evaluates the potential risks to receptors within each subbasin of the watershed as well as at a watershed-wide scale. The WOC system has been exposed to contaminant releases from Oak Ridge National Laboratory and associated operations since 1943 and continues to receive contaminants from adjacent waste area groupings.

White Oak Creek Watershed: Melton Valley Area Remedial Investigation Report, Oak Ridge National Laboratory, Oak Ridge, Tennessee: Volume 3 Appendix C

International Nuclear Information System (INIS)

1996-11-01

This report provides details on the baseline ecological risk assessment conducted in support of the Remedial Investigation (RI) Report for the Melton Valley areas of the White Oak Creek watershed (WOCW). The RI presents an analysis meant to enable the US Department of Energy (DOE) to pursue a series of remedial actions resulting in site cleanup and stabilization. The ecological risk assessment builds off of the WOCW screening ecological risk assessment. All information available for contaminated sites under the jurisdiction of the US Department of Energy's Comprehensive Environmental Response, Compensation, and Liability Act Federal Facilities Agreement within the White Oak Creek (WOC) RI area has been used to identify areas of potential concern with respect to the presence of contamination posing a potential risk to ecological receptors within the Melton Valley area of the White Oak Creek watershed. The risk assessment report evaluates the potential risks to receptors within each subbasin of the watershed as well as at a watershed-wide scale. The WOC system has been exposed to contaminant releases from Oak Ridge National Laboratory and associated operations since 1943 and continues to receive contaminants from adjacent waste area groupings

Effects of competition and herbivory over woody seedling growth in a temperate woodland trump the effects of elevated CO2.

Science.gov (United States)

Collins, L; Boer, M M; de Dios, V Resco; Power, S A; Bendall, E R; Hasegawa, S; Hueso, R Ochoa; Nevado, J Piñeiro; Bradstock, R A

2018-04-27

A trend of increasing woody plant density, or woody thickening, has been observed across grassland and woodland ecosystems globally. It has been proposed that increasing atmospheric [CO 2 ] is a major driver of broad scale woody thickening, though few field-based experiments have tested this hypothesis. Our study utilises a Free Air CO 2 Enrichment experiment to examine the effect of elevated [CO 2 ] (eCO 2 ) on three mechanisms that can cause woody thickening, namely (i) woody plant recruitment, (ii) seedling growth, and (iii) post-disturbance resprouting. The study took place in a eucalypt-dominated temperate grassy woodland. Annual assessments show that juvenile woody plant recruitment occurred over the first 3 years of CO 2 fumigation, though eCO 2 did not affect rates of recruitment. Manipulative experiments were established to examine the effect of eCO 2 on above-ground seedling growth using transplanted Eucalyptus tereticornis (Myrtaceae) and Hakea sericea (Proteaceae) seedlings. There was no positive effect of eCO 2 on biomass of either species following 12 months of exposure to treatments. Lignotubers (i.e., resprouting organs) of harvested E. tereticornis seedlings that were retained in situ for an additional year were used to examine resprouting response. The likelihood of resprouting and biomass of resprouts increased with lignotuber volume, which was not itself affected by eCO 2 . The presence of herbaceous competitors and defoliation by invertebrates and pathogens were found to greatly reduce growth and/or resprouting response of seedlings. Our findings do not support the hypothesis that future increases in atmospheric [CO 2 ] will, by itself, promote woody plant recruitment in eucalypt-dominated temperate grassy woodlands.

Hydrologic response of mechanical mastication in juniper woodland in Utah

Science.gov (United States)

Various vegetation control methods have been used to reduce juniper (Juniperus ssp.) woodland encroachment. Mechanical mastication (reducing trees to a mulch residue) has recently been used in some western states. We investigated the hydrologic impacts of rubber tire tracks from the masticating vehi...

Urbanization level and woodland size are major drivers of woodpecker species richness and abundance.

Directory of Open Access Journals (Sweden)

Lukasz Myczko

Full Text Available Urbanization is a process globally responsible for loss of biodiversity and for biological homogenization. Urbanization may have a direct negative impact on species behaviour and indirect effects on species populations through alterations of their habitats, for example patch size and habitat quality. Woodpeckers are species potentially susceptible to urbanization. These birds are mostly forest specialists and the development of urban areas in former forests may be an important factor influencing their richness and abundance, but documented examples are rare. In this study we investigated how woodpeckers responded to changes in forest habitats as a consequence of urbanization, namely size and isolation of habitat patches, and other within-patch characteristics. We selected 42 woodland patches in a gradient from a semi-natural rural landscape to the city centre of Poznań (Western Poland in spring 2010. Both species richness and abundance of woodpeckers correlated positively to woodland patch area and negatively to increasing urbanization. Abundance of woodpeckers was also positively correlated with shrub cover and percentage of deciduous tree species. Furthermore, species richness and abundance of woodpeckers were highest at moderate values of canopy openness. Ordination analyses confirmed that urbanization level and woodland patch area were variables contributing most to species abundance in the woodpecker community. Similar results were obtained in presence-absence models for particular species. Thus, to sustain woodpecker species within cities it is important to keep woodland patches large, multi-layered and rich in deciduous tree species.

Urbanization level and woodland size are major drivers of woodpecker species richness and abundance.

Science.gov (United States)

Myczko, Lukasz; Rosin, Zuzanna M; Skórka, Piotr; Tryjanowski, Piotr

2014-01-01

Urbanization is a process globally responsible for loss of biodiversity and for biological homogenization. Urbanization may have a direct negative impact on species behaviour and indirect effects on species populations through alterations of their habitats, for example patch size and habitat quality. Woodpeckers are species potentially susceptible to urbanization. These birds are mostly forest specialists and the development of urban areas in former forests may be an important factor influencing their richness and abundance, but documented examples are rare. In this study we investigated how woodpeckers responded to changes in forest habitats as a consequence of urbanization, namely size and isolation of habitat patches, and other within-patch characteristics. We selected 42 woodland patches in a gradient from a semi-natural rural landscape to the city centre of Poznań (Western Poland) in spring 2010. Both species richness and abundance of woodpeckers correlated positively to woodland patch area and negatively to increasing urbanization. Abundance of woodpeckers was also positively correlated with shrub cover and percentage of deciduous tree species. Furthermore, species richness and abundance of woodpeckers were highest at moderate values of canopy openness. Ordination analyses confirmed that urbanization level and woodland patch area were variables contributing most to species abundance in the woodpecker community. Similar results were obtained in presence-absence models for particular species. Thus, to sustain woodpecker species within cities it is important to keep woodland patches large, multi-layered and rich in deciduous tree species.

Will ecosystem management supply woodland caribou habitat in northwestern Ontario?

Directory of Open Access Journals (Sweden)

David L. Euler

1998-03-01

Full Text Available Ecosystem management is emerging as an important concept in managing forests. Although the basic conceptual idea is not new, important defining principles are developing that elucidate some of the specific attributes of ecosystem management. These principles include: the maintenance of all ecosystems in the managed forest, rhe emulation of natural disturbance patterns on rhe landscape and the insurance that structure and function of forested ecosystems are conserved. Forest management has an impact on woodland caribou (Rangifer tarandus caribou, although the presence of wolves (Canis lupus and moose (Alces alces in the same northern ecosystems also affects the caribou-forestry interacrion. Specific management for caribou as a featured species has been proposed, based on managing large landscape blocks. Ecosystem management would also produce habitat in a manner that might accomplish the goal of conserving woodland caribou as well as maintaining other important ecosystem functions.

Decision-support tool for management of miombo woodlands: a ...

African Journals Online (AJOL)

The model complexity is well adapted to the data quality and abundance, and it is dependent on proxies of some main drivers of the dynamic processes. The development of the matrix model is a step forward facilitating better decisions in the management of miombo woodlands. However, data ranges used for calibrating ...

Estimating wood volume from canopy area in deciduous woodlands ...

African Journals Online (AJOL)

In this study we tested the predictive ability of canopy area in estimating wood volume in deciduous woodlands of Zimbabwe. The study was carried out in four sites of different climatic conditions. We used regression analysis to statistically quantify the prediction of wood volume from canopy area at species and stand level ...

New relationships among the sudden oak death pathogen, bark and ambrosia beetles, and fungi colonizing coast live oaks

Science.gov (United States)

Nadir Erbilgin; Brice A. McPherson; Pierluigi Bonello; David L. Wood; Andrew J. Nelson

2008-01-01

Sudden oak death (SOD) has had devastating effects on several oak species in many California coastal forests. Phytophthora ramorum has been identified as the primary causal agent of sudden oak death. While the pathogen may be capable of killing mature trees, it is likely that in nature opportunistic organisms play significant roles in the decline and...

A meta-analysis of the fire-oak hypothesis: Does prescribed burning promote oak reproduction in eastern North America

Science.gov (United States)

Patrick H. Brose; Daniel C. Dey; Ross J. Phillips; Thomas A. Waldrop

2013-01-01

The fire-oak hypothesis asserts that the current lack of fire is a reason behind the widespread oak (Quercus spp.) regeneration difficulties of eastern North America, and use of prescribed burning can help solve this problem. We performed a meta-analysis on the data from 32 prescribed fire studies conducted in mixed-oak forests to test whether they...

Multi-scale associations between vegetation cover and woodland bird communities across a large agricultural region.

Directory of Open Access Journals (Sweden)

Karen Ikin

Full Text Available Improving biodiversity conservation in fragmented agricultural landscapes has become an important global issue. Vegetation at the patch and landscape-scale is important for species occupancy and diversity, yet few previous studies have explored multi-scale associations between vegetation and community assemblages. Here, we investigated how patch and landscape-scale vegetation cover structure woodland bird communities. We asked: (1 How is the bird community associated with the vegetation structure of woodland patches and the amount of vegetation cover in the surrounding landscape? (2 Do species of conservation concern respond to woodland vegetation structure and surrounding vegetation cover differently to other species in the community? And (3 Can the relationships between the bird community and the woodland vegetation structure and surrounding vegetation cover be explained by the ecological traits of the species comprising the bird community? We studied 103 woodland patches (0.5 - 53.8 ha over two time periods across a large (6,800 km(2 agricultural region in southeastern Australia. We found that both patch vegetation and surrounding woody vegetation cover were important for structuring the bird community, and that these relationships were consistent over time. In particular, the occurrence of mistletoe within the patches and high values of woody vegetation cover within 1,000 ha and 10,000 ha were important, especially for bird species of conservation concern. We found that the majority of these species displayed similar, positive responses to patch and landscape vegetation attributes. We also found that these relationships were related to the foraging and nesting traits of the bird community. Our findings suggest that management strategies to increase both remnant vegetation quality and the cover of surrounding woody vegetation in fragmented agricultural landscapes may lead to improved conservation of bird communities.

The supply and demand situation for oak timber

Science.gov (United States)

Kenneth L. Quigley

1971-01-01

Twenty oak species in the eastern United States account for one-third of the hardwood sawtimber volume and almost 10 percent of both hardwood and softwood growing-stock volume. The oak-hickory and oak-pine forest types occupy about 38 percent of the forest land in the eastern United States. Oak timber volume is increasing. Annual growth exceeds annual removals by about...

Comprehensive integrated planning: A process for the Oak Ridge Reservation, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1998-05-01

The Oak Ridge Comprehensive Integrated Plan is intended to assist the US Department of Energy (DOE) and contractor personnel in implementing a comprehensive integrated planning process consistent with DOE Order 430.1, Life Cycle Asset Management and Oak Ridge Operations Order 430. DOE contractors are charged with developing and producing the Comprehensive Integrated Plan, which serves as a summary document, providing information from other planning efforts regarding vision statements, missions, contextual conditions, resources and facilities, decision processes, and stakeholder involvement. The Comprehensive Integrated Plan is a planning reference that identifies primary issues regarding major changes in land and facility use and serves all programs and functions on-site as well as the Oak Ridge Operations Office and DOE Headquarters. The Oak Ridge Reservation is a valuable national resource and is managed on the basis of the principles of ecosystem management and sustainable development and how mission, economic, ecological, social, and cultural factors are used to guide land- and facility-use decisions. The long-term goals of the comprehensive integrated planning process, in priority order, are to support DOE critical missions and to stimulate the economy while maintaining a quality environment

Comprehensive integrated planning: A process for the Oak Ridge Reservation, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

The Oak Ridge Comprehensive Integrated Plan is intended to assist the US Department of Energy (DOE) and contractor personnel in implementing a comprehensive integrated planning process consistent with DOE Order 430.1, Life Cycle Asset Management and Oak Ridge Operations Order 430. DOE contractors are charged with developing and producing the Comprehensive Integrated Plan, which serves as a summary document, providing information from other planning efforts regarding vision statements, missions, contextual conditions, resources and facilities, decision processes, and stakeholder involvement. The Comprehensive Integrated Plan is a planning reference that identifies primary issues regarding major changes in land and facility use and serves all programs and functions on-site as well as the Oak Ridge Operations Office and DOE Headquarters. The Oak Ridge Reservation is a valuable national resource and is managed on the basis of the principles of ecosystem management and sustainable development and how mission, economic, ecological, social, and cultural factors are used to guide land- and facility-use decisions. The long-term goals of the comprehensive integrated planning process, in priority order, are to support DOE critical missions and to stimulate the economy while maintaining a quality environment.

Tree-shrub associations in grazed woodlands: First rodents, then cattle?

NARCIS (Netherlands)

Smit, C.; Verwijmeren, M.

2011-01-01

Spatial associations of tree saplings with spiny or toxic plants in grazed woodlands are generally explained by associational resistance, i. e., protection against grazing via a well-defended neighbor. In this study, we tested whether directed seed dispersal and post-dispersal seed removal by wood

Oak Ridge Leadership Computing Facility (OLCF)

Data.gov (United States)

Federal Laboratory Consortium — The Oak Ridge Leadership Computing Facility (OLCF) was established at Oak Ridge National Laboratory in 2004 with the mission of standing up a supercomputer 100 times...

US Department of Energy Oak Ridge Operations Environmental Management Public Involvement Plan for the Oak Ridge Reservation

International Nuclear Information System (INIS)

1996-03-01

This document was prepared in accordance with CERCLA requirements for writing community relations plans. It includes information on how the DOE Oak Ridge Operations Office prepares and executes Environmental Management Community relations activities. It is divided into three sections: the public involvement plan, public involvement in Oak Ridge, and public involvement in 1995. Four appendices are also included: environmental management in Oak Ridge; community and regional overview; key laws, agreements, and policy; and principal contacts

Allometric Models Based on Bayesian Frameworks Give Better Estimates of Aboveground Biomass in the Miombo Woodlands

Directory of Open Access Journals (Sweden)

Shem Kuyah

2016-02-01

Full Text Available The miombo woodland is the most extensive dry forest in the world, with the potential to store substantial amounts of biomass carbon. Efforts to obtain accurate estimates of carbon stocks in the miombo woodlands are limited by a general lack of biomass estimation models (BEMs. This study aimed to evaluate the accuracy of most commonly employed allometric models for estimating aboveground biomass (AGB in miombo woodlands, and to develop new models that enable more accurate estimation of biomass in the miombo woodlands. A generalizable mixed-species allometric model was developed from 88 trees belonging to 33 species ranging in diameter at breast height (DBH from 5 to 105 cm using Bayesian estimation. A power law model with DBH alone performed better than both a polynomial model with DBH and the square of DBH, and models including height and crown area as additional variables along with DBH. The accuracy of estimates from published models varied across different sites and trees of different diameter classes, and was lower than estimates from our model. The model developed in this study can be used to establish conservative carbon stocks required to determine avoided emissions in performance-based payment schemes, for example in afforestation and reforestation activities.

An ecologically based approach to oak silviculture: a synthesis of 50 years of oak ecosystem research in North America

Science.gov (United States)

Daniel C. Dey; Alejandro A. Royo; Patrick H. Brose; Todd F. Hutchinson; Martin A. Spetich; Scott H. Stoleson

2010-01-01

Oak (Quercus L.) is an abundant and widely distributed genus in eastern North America. A history of periodic fire, grazing, canopy disturbance and timber harvesting has favored oak's dominance. But, changes in this regime toward much less fire or complete fire suppression, and selective cutting are causing the successional replacement of oak....

Modeling wind fields and fire propagation following bark beetle outbreaks in spatially-heterogeneous pinyon-juniper woodland fuel complexes

Science.gov (United States)

Rodman R. Linn; Carolyn H. Sieg; Chad M. Hoffman; Judith L. Winterkamp; Joel D. McMillin

2013-01-01

We used a physics-based model, HIGRAD/FIRETEC, to explore changes in within-stand wind behavior and fire propagation associated with three time periods in pinyon-juniper woodlands following a drought-induced bark beetle outbreak and subsequent tree mortality. Pinyon-juniper woodland fuel complexes are highly heterogeneous. Trees often are clumped, with sparse patches...

Moth species richness, abundance and diversity in fragmented urban woodlands: implications for conservation and management strategies

OpenAIRE

Lintott, P.; Bunnefeld, N.; Fuentes-Montemayor, E.; Minderman, J.; Blackmore, L.; Goulson, D.; Park, K.

2014-01-01

Urban expansion threatens global biodiversity through the destruction of natural and semi-natural habitats and increased levels of disturbance. Whilst woodlands in urban areas may reduce the impact of urbanisation on biodiversity, they are often subject to under or over-management and consist of small, fragmented patches which may be isolated. Effective management strategies for urban woodland require an understanding of the\\ud ecology and habitat requirements of all relevant taxa. Yet, littl...

Effective porosity and density of carbonate rocks (Maynardville Limestone and Copper Ridge Dolomite) within Bear Creek Valley on the Oak Ridge Reservation based on modern petrophysical techniques

International Nuclear Information System (INIS)

Dorsch, J.

1997-02-01

The purpose of this study is to provide quantitative data on effective porosity of carbonate rock from the Maynardville Limestone and Copper Ridge Dolomite within Bear Creek Valley based on modern petrophysical techniques. The data will be useful for groundwater-flow and contaminant-flow modeling in the vicinity of the Y-12 Plant on the Oak Ridge Reservation (ORR). Furthermore, the data provides needed information on the amount of interconnected pore space potentially available for operation of matrix diffusion as a transport process within the fractured carbonate rock. A second aspect of this study is to compare effective porosity data based on modern petrophysical techniques to effective porosity data determined earlier by Goldstrand et al. (1995) with a different technique. An added bonus of the study is quantitative data on the bulk density and grain density of dolostone and limestone of the Maynardville Limestone and Copper Ridge Dolomite which might find use for geophysical modeling on the ORR

Intensity of 137Cs accumulation by macromycetes of oak-hornbeam forests

International Nuclear Information System (INIS)

Orlov, A.A.; Kurbet, T.V.

2005-01-01

The intensity of 137 Cs accumulation by fruit bodies of macromycetes of 25 species were studied under conditions of fresh oak forests in oak-hornbeam forests of Podolsk Hills (Ukraine). It was found the intraspecific differences of average values of 137 Cs specific activity in mushrooms fruit bodies on the same forest plots were about 35 times and average values of transfer factor - about 45 times; the ranked row of mushroom species was build up according their average values. It was shown, the row →forest litter saprotrophes→humus sapritrophes→xylotrophes-sapritrophes - is formed according to intensity of 137 Cs accumulation in fruit bodies ecological-trophic groups of macromycete. Permissible levels for density of 137 Cs soil contamination to preserve edible mushrooms were calculated; and it was drawn a conclusion to the effect that studied species of mushrooms can be presented without any limits. (author)

Analysis of forest stands used by wintering woodland caribou in Ontario

Directory of Open Access Journals (Sweden)

K. Antoniak

1998-03-01

Full Text Available Two summers' field surveys at 9 locations in northwestern Ontario showed that woodland caribou (Rangifer tarandus caribou wintering areas supported jack pine and black spruce stands with low tree densities (mean 1552 trees/ ha, 39% of a fully stocked stand, low basal areas (mean 14.14 m2/ha, low volumes (mean 116 mVha, 68% of Normal Yield Tables and short heights (95% of stands 12 m or less. Ecologically, most sights were classed V30. Significantly more lichen (averaging 39% lichen ground cover was found on plots used by caribou. Three measured areas showed few shrubs, possibly enhancing escape possibilities and reducing browse attractive to moose. An HIS model predicted known locations of caribou winter habitat from FRI data with 76% accuracy. Landsat imagery theme 3 (open conifer produced 74% accuracy. Combining these methods permitted prediction of all 50 test sites. The low volumes of timber found in caribou wintering areas suggest that setting aside reserves for caribou winter habitat would not sacrifice as much wood product value as might at first appear.

Competitive responses of seedlings and understory plants in longleaf pine woodlands: separating canopy influences above and below ground

Science.gov (United States)

Stephen D. Pecot; Robert J. Mitchell; Brian J. Palik; Barry Moser; J. Kevin Hiers

2007-01-01

A trenching study was used to investigate above- and below-ground competition in a longleaf pine (Pinus palustris P. Mill.) woodland. Trenched and nontrenched plots were replicated in the woodland matrix, at gap edges, and in gap centers representing a range of overstory stocking. One-half of each plot received a herbicide treatment to remove the...

Forecasting the future of coast live oak forests in the face of sudden oak death

Science.gov (United States)

Letty B. Brown; Barbara Allen-Diaz

2006-01-01

Little is known about the potential short- and long-term impacts of sudden oak death (SOD) on forest structure and composition. This study began in 2002 to evaluate the effects of SOD on coast live oak (Quercus agrifolia) - California bay laurel (Umbellularia californica) forests over a gradient of Phytophthora ramorum...

Development, succession, and stand dynamics of upland oak forests in the Wisconsin Driftless Area: Implications for oak regeneration and management

Science.gov (United States)

Megan L. Buchanan; Kurt F. Kipfmueller; Anthony W. D' Amato

2017-01-01

Throughout the deciduous forests of the eastern United States, oak (Quercus) regeneration has declined in stands historically dominated by oak species. In the Wisconsin Driftless Area, the level of decline in oak regeneration is variable and influenced by stand structural development, historical disturbance regime, abiotic site characteristics, and...

Amplification of North American Red Oak Microsatellite Markers in European White Oaks and Chinese Chestnut

Science.gov (United States)

P. R. Aldrich; M. Jagtap; C. H. Michler; J. Romero-Severson

2003-01-01

We examined the cross-species amplification success of thirty microsatellite markers developed from North American northern red oak (Quercus rubra) in other members of the family Fagaceae. Sixteen of these markers are newly developed and we report primer sequences and amplification conditions here. Twelve of the thirty (40.0%) red oak markers...

Runoff, erosion, and restoration studies in piñon-juniper woodlands of the Pajarito Plateau

Science.gov (United States)

Allen, Craig D.; Johnson, Peggy S.

2001-01-01

Piñon-juniper woodlands are one of the most extensive vegetation types in New Mexico, including large portions of the Pajarito Plateau. The woodland soils on local mesas largely formed under different vegetation during cooler, moister conditions of the late Pleistocene; in other words, they are over 10,000 years old, and many are over 100,000 years old (McFadden et al., 1996). Changes in climate and vegetation in the early Holocene (8,500– 6,000 years ago) led to at least localized episodes of soil erosion on adjoining uplands (Reneau and McDonald, 1996; Reneau et al., 1996). During this time, the dominant climatic and associated vegetation patterns of the modern southwestern United States developed, including grasslands, piñon-juniper woodlands, and ponderosa pine savannas (Allen et al., 1998). On the basis of local fire history, the young ages of most piñon-juniper trees here, and soils data, we believe that many upland mesa areas now occupied by dense piñon-juniper woodlands were formerly more open, with fewer trees and well-developed herbaceous understories that: (1) protected the soil from excessive erosion during intense summer thunderstorm events, and (2) provided a largely continuous fuel matrix, which allowed surface fires to spread and maintain these vegetation types (Fig. 1). In contrast, rocky canyon walls have probably changed relatively little through the centuries, as grazing and fire suppression had fewer effects on such sites.

Estimation of arboreal lichen biomass available to woodland caribou in Hudson Bay lowland black spruce sites

Directory of Open Access Journals (Sweden)

Sarah K. Proceviat

2003-04-01

Full Text Available An arboreal lichen index to be utilized in assessing woodland caribou habitat throughout northeastern Ontario was developed. The "index" was comprised of 5 classes, which differentiated arboreal lichen biomass on black spruce trees, ranging from maximal quantities of arboreal lichen (class 5 to minimal amounts of arboreal lichen (class 1. This arboreal lichen index was subsequently used to estimate the biomass of arboreal lichen available to woodland caribou on lowland black spruce sites ranging in age from 1 year to 150 years post-harvest. A total of 39 sites were assessed and significant differences in arboreal lichen biomass were found, with a positive linear relationship between arboreal lichen biomass and forest age. It is proposed that the index be utilized by government and industry as a means of assessing the suitability of lowland black spruce habitat for woodland caribou in this region.

Oak Ridge Reservation environmental report for 1991

International Nuclear Information System (INIS)

Mucke, P.C.

1992-10-01

The Oak Ridge Reservation Environmental Report for 1991 is the 21st in a series that began in 1971. The report documents the annual results of a comprehensive program to estimate the impact of the US Department of Energy (DOE) Oak Ridge operations upon human health and the environment. The report is organized into ten sections that address various aspects of effluent monitoring, environmental surveillance, dose assessment, waste management, and quality assurance. A compliance summary gives a synopsis of the status of each facility relative to applicable state and federal regulations. Data are included for the following: Oak Ridge Y-12 Plant; Oak Ridge National Laboratory (ORNL); and Oak Ridge K-25 Site. Effluent monitoring and environmental surveillance programs are intended to serve as effective indicators of contaminant releases and ambient contaminant concentrations that have the potential to result in adverse impacts to human health and the environment

The history of widespread decrease in oak dominance exemplified in a grassland--forest landscape

Science.gov (United States)

Brice B. Hanberry; Daniel C. Dey; Hong S. He

2014-01-01

Regionally-distinctive open oak forest ecosystems have been replaced either by intensive agriculture and grazing fields or by denser forests throughout eastern North America and Europe. To quantify changes in tree communities and density in the Missouri Plains, a grassland-forest landscape, we used historical surveys from1815 to 1864 and current surveys from 2004 to...

Woody debris dynamics in Interior West forests and woodlands

Science.gov (United States)

John D. Shaw; James Long; Raffaella Marzano; Matteo Garbarino

2012-01-01

Managers are interested in the dynamics of down woody material because of its role as a fuel component, a feature of wildlife habitat, a carbon pool, and other characteristics. We analyzed nearly 9,000 plots from the Interior West, spanning the range from sparse juniper and mesquite woodland to dense spruce-fir forests, in order to characterize down woody material as...

Gopher Tortoise (Gopherus polyphemus) Densities in Coastal Scrub and Slash Pine Flatwoods in Florida

Science.gov (United States)

Breininger, David R.; Schmalzer, Paul A.; Hinkle, C. Ross

1994-01-01

Densities of gopher tortoises were compared with habitat characteristics in scrub and in flatwood habitats on the Kennedy Space Center, Florida. Tortoises were distributed widely among habitat types and did not have higher densities in well-drained (oak-palmetto) than in poorly-drained (saw palmetto) habitats. Fall densities of tortoises ranged from a mean of 2.7 individuals/ha in disturbed habitat to 0.0 individuals/ha in saw palmetto habitat. Spring densities of tortoises ranged from a mean of 2.5 individuals/ha in saw palmetto habitat to 0.7 individuals/ha in oak-palmetto habitat. Densities of tortoises were correlated positively with the percent herbaceous cover, an indicator of food resources. Plots were divided into three burn classes; these were areas burned within three years, burned four to seven years, and unburned for more than seven years prior to the study. Relationships between densities of tortoises and time-since-fire classes were inconsistent.

Seeding and planting upland oaks

Science.gov (United States)

1989-01-01

Oaks can be planted or seeded in uplands to: (1) afforest old fields, strip-mined areas, or other areas devoid of trees, and (2) supplement natural reproduction within existing forests. Planting is usually more successful than direct seeding. But even under good conditions survival and growth of planted oak has been considerably poorer than with conifers and other...

Preliminary flora of the Sierra Bacadehuachi, Sonora, Mexico

Science.gov (United States)

Thomas R. Van Devender; Ana Lilia Reina-Guerrero; George M. Ferguson; George Yatskievych; Beatriz E. Loyola-Reina; Gertrudis Yanes-Arvayo; Maria de la Paz Montanez-Armenta; John L. Anderson; Stephen F. Hale; Sky Jacobs

2013-01-01

The Sierra Bacadéhuachi in east-central Sonora is the westernmost mountain range in the Sierra Madre Occidental (SMO), located east of Bacadéhuachi, Municipio de Bacadéhuachi, 34 km east of the Chihuahua border, and 165 km south of the Arizona border. The vegetation ranges from lowland foothills thornscrub up through desert grassland to oak woodland and pine-oak forest...

The mighty oak faces challenges in the Pacific West

Science.gov (United States)

Gail Wells

2010-01-01

In popular imagination, the oak tree stands for strength, endurance, and longevity. But in the coastal lowlands and central valleys of British Columbia, Washington, Oregon, and California, oaks face a battery of natural and human-induced threats. Sudden oak death, caused by a virulent pathogen identified in 2000, has killed millions of tanoaks, California black oaks,...

An aerial radiological survey of the Oak Ridge Reservation and surrounding area, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Maurer, R.J.

1989-09-01

An aerial radiological survey of the Oak Ridge Reservation (ORR) and surrounding area in Oak Ridge, Tennessee, was conducted from September 12--29, 1989. The purpose of the survey was to measure and document the site's terrestrial radiological environment for use in effective environmental management and emergency response planning. The aerial survey was flown at an altitude of 91 meters (300 feet) along a series of parallel lines 152 meters (500 feet) apart. The survey encompassed an area of 440 square kilometers (170 square miles) as defined by the Tennessee Valley Authority Map S-16A of the entire Oak Ridge Reservation and adjacent area. The results of the aerial survey are reported as inferred exposure rates at 1 meter above ground level (AGL) in the form of a radiation contour map. Typical background exposure rates were found to vary from 5 to 14 microroentgens per hour (μR/h). The man-made radionuclides, cobalt-60, cesium-137, and protactinium-234m (a radioisotope indicative of depleted uranium), were detected at several facilities on the site. In support of the aerial survey, ground-based exposure rate and soil sample measurements were obtained at several locations within the survey boundary. In addition to the large scale aerial survey, two special flyovers were requested by the Department of Energy. The first request was to conduct a survey of a 1-mile x 2-mile area in south Knoxville, Tennessee. The area had been used previously to store contaminated scrap metals from operations at the Oak Ridge site. The second request was to fly several passes over a 5-mile length of railroad tracks leading from the Oak Ridge Y-12 Plant, north through the city of Oak Ridge. The railroad tracks had been previously used in the transport of cesium-137

Litter Species Composition and Topographic Effects on Fuels and Modeled Fire Behavior in an Oak-Hickory Forest in the Eastern USA.

Science.gov (United States)

Dickinson, Matthew B; Hutchinson, Todd F; Dietenberger, Mark; Matt, Frederick; Peters, Matthew P

2016-01-01

Mesophytic species (esp. Acer rubrum) are increasingly replacing oaks (Quercus spp.) in fire-suppressed, deciduous oak-hickory forests of the eastern US. A pivotal hypothesis is that fuel beds derived from mesophytic litter are less likely than beds derived from oak litter to carry a fire and, if they do, are more likely to burn at lower intensities. Species effects, however, are confounded by topographic gradients that affect overstory composition and fuel bed decomposition. To examine the separate and combined effects of litter species composition and topography on surface fuel beds, we conducted a common garden experiment in oak-hickory forests of the Ohio Hills. Each common garden included beds composed of mostly oak and mostly maple litter, representative of oak- and maple-dominated stands, respectively, and a mixture of the two. Beds were replenished each fall for four years. Common gardens (N = 16) were established at four topographic positions (ridges, benches on south- and northeast-facing slopes, and stream terraces) at each of four sites. Litter source and topographic position had largely independent effects on fuel beds and modeled fire dynamics after four years of development. Loading (kg m-2) of the upper litter layer (L), the layer that primarily supports flaming spread, was least in more mesic landscape positions and for maple beds, implying greater decomposition rates for those situations. Bulk density in the L layer (kg m-3) was least for oak beds which, along with higher loading, would promote fire spread and fireline intensity. Loading and bulk density of the combined fermentation and humic (FH) layers were least on stream terrace positions but were not related to species. Litter- and FH-layer moistures during a 5-day dry-down period after a rain event were affected by time and topographic effects while litter source effects were not evident. Characteristics of flaming combustion determined with a cone calorimeter pointed to greater fireline

An examination of recovery planning for forest-dwelling woodland caribou (Rangifer tarandus caribou in Ontario, Canada

Directory of Open Access Journals (Sweden)

Christopher J. A. Wilkinson

2008-04-01

Full Text Available Ontario’s population of forest-dwelling woodland caribou is listed both federally and provincially as a species at risk. It is estimated that 20 000 woodland caribou remain in Ontario, of which approximately one quarter inhabit the boreal forest and are described as the sedentary forest-dwelling population. This paper examines the recovery strategy for this population developed by the Ministry of Natural Resources, as well as discussing the implications of provincial forestry policy on woodland caribou management. Commercial timber harvesting will likely soon be allowed in parts of the northern third of the province, in which woodland caribou habitat currently is relatively unimpaired by industrial development. Abstract in Norwegian / Sammendrag:Planlegging for bevaring av skogsøkotypen av Rangifer tarandus caribou i Ontario, CanadaSkogsvillreinen av skogsøkotypen i Ontario er vurdert som sårbar både føderalt og på provinsnivå. Av provinsens rundt 20 000 skogsvillrein hører omtrent en fjerdepart til den stasjonære skogsboende skogsøkoypen. Artikkelen ser på bevaringsstrategien som er utarbeidet av naturressursdepartementet i Ontario for denne spesielle bestanden og diskuterer konsekvensene for villreinen av provinsens skogpolitikk. Kommersiell hogst vil mest sannsynlig og snart bli tillatt i deler av Ontarios nordlige tredel der skogvillreinens leveområder er relativt upåvirket av industriell virksomhet.

Fuelwood and woodland improvement (or damage)

International Nuclear Information System (INIS)

Geisler, J.C.

1991-01-01

A 1985 survey (Green) of fuelwood use found that over one-fourth (26.4 percent) of Arkansas households burned fuelwood during the 1984-1985 heating season. More than 65 percent of the wood is self cut, and nearly one-half (47.7 percent) was cut from live timber. Removal of live timber through fuelwood cutting affords an opportunity to significantly improve hardwood or mixed hardwood-pine stands. It also provides an opportunity for extensive damage. This paper discusses the positive and negative impacts of fuelwood cutting and negative impacts of fuelwood cutting in live timber stands. It suggests programs for realizing woodland improvement through fuelwood cutting

Oak Ridge Reservation environmental report for 1989

International Nuclear Information System (INIS)

Jacobs, V.A.; Wilson, A.R.

1990-10-01

This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a ''stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1

Oak Ridge Reservation environmental report for 1989

Energy Technology Data Exchange (ETDEWEB)

Jacobs, V.A.; Wilson, A.R. (eds.)

1990-10-01

This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1.

Changing forest-woodland-savanna mosaics in Uganda: with implications for conservation

NARCIS (Netherlands)

Nangendo, G.

2005-01-01

Forest-Woodland-Savanna (FWS) mosaics are complex, highly varied and dynamic landscapes.Until recently, they were considered poor in terms of biodiversity. Consequently, only few scientific studies have been done on them and little attention has been paid to their

Bird communities of gambel oak: a descriptive analysis

Science.gov (United States)

Andreas Leidolf; Michael L. Wolfe; Rosemary L. Pendleton

2000-01-01

Gambel oak (Quercus gambelii Nutt.) covers 3.75 million hectares (9.3 million acres) of the western United States. This report synthesizes current knowledge on the composition, structure, and habitat relationships of gambel oak avian communities. It lists life history attributes of 183 bird species documented from gambel oak habitats of the western...

Inventories of fallout 21Pb and 137Cs radionuclides in moorland and woodland soils around Edinburgh urban area (UK)

International Nuclear Information System (INIS)

Likuku, A.S.; Branford, D.; Fowler, D.; Weston, K.J.

2006-01-01

Inventories of fallout 21 Pb and 137 Cs have been measured in moorland and woodland soils around the Edinburgh urban area, using a high purity germanium detector. The 21 Pb inventories in moorland soils were relatively uniform, with a mean value of 2520 ± 270 Bq m -2 . The mean 137 Cs inventory in moorland soils varied greatly from 1310 to 2100 Bq m -2 , with a mean value of 1580 ± 310 Bq m -2 . The variability was ascribed mainly to the non-uniform distribution of fallout Chernobyl 137 Cs. The mean 21 Pb and 137 Cs inventories in woodland canopy soils were found to be 3630 ± 380 Bq m -2 and 2510 ± 510 Bq m -2 , respectively. At sites for which both moorland and woodland data were available, the mean inventories provided fairly similar average enhancements of (47 ± 7)% and (46 ± 18)% of 21 Pb and 137 Cs under woodland canopy soils relative to open grassland soils, respectively. The enhancement factors are broadly in line with other independent findings in literature. Enhancement of both 21 Pb and 137 Cs in woodland soils relative to moorland soils is, in part, due to deposition by impaction during air turbulence, wash-off, gravitational settling and deposition during leaf senescence. Results of this study suggest that these processes affect both 21 Pb and 137 Cs carrier aerosols in a similar way

Anti nutritional evaluation of the flour of the nipples of holm oak (quercus ilex) and oak cork (quercus suber) Raw and pressure-sealed

International Nuclear Information System (INIS)

El Mahi, F. Z.

2009-01-01

The present study contributes to the development of the food potential of the nipples of oak like new resources likely to be exploited on an industrial scale for their use in animal feeds. Our work relates to two species S of nipples of oak, edible, the holm oak and the other fodder one, the oak cork known for their spontaneousness and their vey significant geographical distribution. (Author)

Hydrologic data summary for the White Oak Creek Watershed at Oak Ridge National Laboratory, Oak Ridge, Tennessee, January--December 1992

International Nuclear Information System (INIS)

Borders, D.M.; Watts, J.A.; Clapp, R.B.; Frederick, B.J.; Gregory, S.M.; Moore, T.D.

1993-06-01

This report summarizes, for the 12-month period (January through December 1992), the available dynamic hydrologic data collected, primarily, on the White Oak Creek (WOC) watershed along with information collected on the surface flow systems which affect the quality or quantity of surface water. The collection of hydrologic data is one component of numerous, ongoing Oak Ridge National Laboratory (ORNL) environmental studies and monitoring programs and is intended to: characterize the quantity and quality of water in the flow system; assist with the planning and assessment of remedial action activities; and provide long-term availability of data and quality assurance

A Dendrochronological Analysis of Red Oak Borer Abundance

Science.gov (United States)

Rose-Marie Muzika; Richard P. Guyette

2004-01-01

Unprecedented outbreaks of red oak borer (Enaphalodes rufulus Haldemann) have occurred in the lower Midwestern United States. Although generally not a mortality agent, red oak borer appears to contribute to general oak decline and mortality. The objective of this project was to explore dendrochronology as a means of determining the role of tree age,...

Reptile and amphibian responses to restoration of fire-maintained pine woodlands

Science.gov (United States)

Roger W Perry; D. Craig Rudolph; Ronald E. Thill

2009-01-01

Fire-maintained woodlands and savannas are important ecosystems for vertebrates in many regions of the world. These ecosystems are being restored by forest managers, but little information exists on herpetofaunal responses to this restoration in areas dominated by shortleaf pine (Pinus echinata). We compared habitat characteristics and...

Models for estimation of tree volume in the miombo woodlands of ...

African Journals Online (AJOL)

Volume of trees is an important parameter in forest management, but only volume models with limited geographical and tree size coverage have previously been developed for Tanzanian miombo woodlands. This study developed models for estimating total, merchantable stem and branches volume applicable for the entire ...

Reconstructing the competitive dynamics of mixed-oak neighborhoods

Science.gov (United States)

Eric K. Zenner; Daniel J. Heggenstaller; Patrick H. Brose; JeriLynn E. Peck; Kim C. Steiner

2012-01-01

The disparity between the potential for latent oak dominance within a stand and their region-wide decline in importance value raises questions about the competitiveness of oaks in early stand dynamics. We reconstructed tree height growth dynamics in mixed-species neighborhoods to determine if currently dominant oaks were ever shorter than their competitors and at what...

Responses of oaks and tanoaks to the sudden oak death pathogen after 8 y of monitoring in two coastal California forests

Science.gov (United States)

Brice A. McPherson; Sylvia R. Mori; David L. Wood; Maggi Kelly; Andrew J. Storer; Pavel Svihra; Richard B. Standiford

2010-01-01

Sudden oak death, caused by Phytophthora ramorum, is widely established in mesic forests of coastal central and northern California. In 2000, we placed 18 plots in two Marin County sites to monitor disease progression in coast live oaks (Quercus agrifolia), California black oaks (Q. kelloggii), and tanoaks (Lithocarpus densiflorus), the species that are most...

Recent land cover and use changes in Miombo woodlands of ...

African Journals Online (AJOL)

Forest and wood land ecosystems in Tanzania occupy more than 45% of the land area, more than two thirds of which made up of the Miombo woodland. The main form of land use in the Miombo region has long been shifting and small-scale sedentary cultivation. The lack of infrastructure and prevalence of deadly diseases ...

Cryptic indirect effects of exurban edges on a woodland community

Science.gov (United States)

R. J. Warren; S. M. Pearson; S. Henry; K. Rossouw; J. P. Love; M. J. Olejniczak; Katherine Elliott; M. A. Bradford

2015-01-01

Exurban development (e.g., second homes) in woodlands spreads urban land use impacts beyond suburbs, but because exurban developments often retain many components of original ecosystem structure—such as a forest canopy rather than open lawn—their ecological impacts may be underestimated. Changes in seed-dispersing ant behavior prompted by exurban land use,...

Characteristics of urban woodlands affecting breeding bird diversity and abundance

Science.gov (United States)

N.G. Tilghman

1987-01-01

Breeding bird communities were studied in 32 forest islands surrounded by urban development. These isolated woodlands in Springfield, Massachusetts, provided breeding habitats for a wider variety of birds (77 species) than previously described for other urban habitats (e.g. four times as many species as found in urban residential areas in the same city in a...

Oak moss extracts in the diagnosis of fragrance contact allergy

DEFF Research Database (Denmark)

Johansen, Jeanne Duus; Heydorn, Siri; Menné, Torkil

2002-01-01

Oak moss absolute is one of the eight ingredients of the fragrance mix (FM) used for diagnosing perfume allergy. Oak moss absolute is an extract prepared from the lichen Evernia prunastri growing on oak trees. It has been shown that the oak moss patch test material from one producer contained resin...

Effects of the goldspotted oak borer, Agrilus auroguttatus, on the health of coast live oak, Quercus agrifolia, in southern California before and after treatment with two systemic insecticides

Science.gov (United States)

Yigen Chen; Mary L. Flint; Tom W. Coleman; Joseph J. Doccola; Donald M. Grosman; David L. Wood; Steven J. Seybold

2015-01-01

The invasive goldspotted oak borer, Agrilus auroguttatus (Coleoptera: Buprestidae), is threatening the health and survival of oak trees in San Diego County, California (Flint and others 2013). The primary oak species colonized and killed in this area include coast live oak (Quercus agrifolia), California black oak (...

A field guide to insects and diseases of California oaks

Science.gov (United States)

Tedmund J. Swiecki; Elizabeth A. Bernhardt

2006-01-01

California has more than twenty-five native species, natural hybrids, and varieties of oaks (Quercus species). The form of these oaks ranges from large trees, up to about 25 m tall, to shrubs no taller than about 1.5 m. California's native oaks include representatives of three oak subgroups or subgenera (Table 1). Hybridization only occurs...

Litter Species Composition and Topographic Effects on Fuels and Modeled Fire Behavior in an Oak-Hickory Forest in the Eastern USA.

Directory of Open Access Journals (Sweden)

Matthew B Dickinson

Full Text Available Mesophytic species (esp. Acer rubrum are increasingly replacing oaks (Quercus spp. in fire-suppressed, deciduous oak-hickory forests of the eastern US. A pivotal hypothesis is that fuel beds derived from mesophytic litter are less likely than beds derived from oak litter to carry a fire and, if they do, are more likely to burn at lower intensities. Species effects, however, are confounded by topographic gradients that affect overstory composition and fuel bed decomposition. To examine the separate and combined effects of litter species composition and topography on surface fuel beds, we conducted a common garden experiment in oak-hickory forests of the Ohio Hills. Each common garden included beds composed of mostly oak and mostly maple litter, representative of oak- and maple-dominated stands, respectively, and a mixture of the two. Beds were replenished each fall for four years. Common gardens (N = 16 were established at four topographic positions (ridges, benches on south- and northeast-facing slopes, and stream terraces at each of four sites. Litter source and topographic position had largely independent effects on fuel beds and modeled fire dynamics after four years of development. Loading (kg m-2 of the upper litter layer (L, the layer that primarily supports flaming spread, was least in more mesic landscape positions and for maple beds, implying greater decomposition rates for those situations. Bulk density in the L layer (kg m-3 was least for oak beds which, along with higher loading, would promote fire spread and fireline intensity. Loading and bulk density of the combined fermentation and humic (FH layers were least on stream terrace positions but were not related to species. Litter- and FH-layer moistures during a 5-day dry-down period after a rain event were affected by time and topographic effects while litter source effects were not evident. Characteristics of flaming combustion determined with a cone calorimeter pointed to greater

Phytophthora ramorum infection in coast live oaks and Shreve's oaks treated with insecticide to prevent beetle colonization

Science.gov (United States)

Brice A. McPherson; David L. Wood; David M. Rizzo; Pavel Svihra; Steve Tjosvold; Andrew J. Storer; Richard B. Standiford

2006-01-01

As the name implies, sudden oak death, caused by Phytophthora ramorum, kills many, if not most of the coast live oaks, Quercus agrifolia, that become infected (McPherson and others, 2005). Several genera of ambrosia and bark beetles (Coleoptera: Scolytidae) colonize bleeding (infected) trees and are suspected to hasten tree death....

Searching for early-warning signals of impending dieback and death in Mediterranean oaks

Science.gov (United States)

Colangelo, Michele; Ripullone, Francesco; Julio Camarero, Jesus; De Micco, Veronica; Gazol, Antonio; Gentilesca, Tiziana; Borghetti, Marco

2017-04-01

than taller conspecifics. Further, irrespective of differences in drought sensitivity, dead trees showed lower radial-growth rates than surviving trees from 10 to 20 years prior to tree death. Contrastingly, differences in wood anatomical traits (vessel lumen size, vessel density) between dead and living trees were not always significant, being species-dependent. Our findings indicate that: (i) tree height is a proxy of the probability of drought-induced death, and (ii) recent growth trends constitute valuable early-warning signals of impending dieback and death in Mediterranean oak species.

Aspects Concerning the Heating/Drying of Oak Planks in a Radiofrequency Field

Directory of Open Access Journals (Sweden)

LAZA (BULC Marcela

2013-05-01

Full Text Available Heat transfer and the evaporation of moisture from wood may be achieved with the help of high-frequency currents, depending on the dielectric properties of wood. Since wood is generally a heterogeneous material, these properties may vary depending on frequency, humidity, temperature and density. This paper presents aspects related to the numerical modeling of the process of heating or drying oak planks arranged in a13.56 MHz radiofrequency applicator, correlated with experiments.

Ecosystem services in the face of invasion: the persistence of native and nonnative spiders in an agricultural landscape.

Science.gov (United States)

Hogg, Brian N; Daane, Kent M

2011-03-01

The presence of intact natural ecosystems in agricultural landscapes can mitigate losses in the diversity of natural enemies and enhance ecosystem services. However, native natural enemies may fail to persist in agroecosystems if invaders dominate species interactions. In this study, native and nonnative spiders were sampled along transects that extended from oak woodland and riparian zones into surrounding California vineyards, to assess the role of natural habitat as a source for spider biodiversity in the vineyard landscape, and to compare the dominance of exotic Cheiracanthium spiders between habitats. Many spider species were more abundant in natural habitat than in vineyards, and numbers of spiders and spider species within vineyards were higher at the vineyard edge adjacent to oak woodland. These results suggest that natural habitat is a key source for spiders in vineyards. The positive effect of oak woodland on the vineyard spider community extended only to the vineyard edge, however. Proportions of Cheiracanthium spiders increased dramatically in the vineyard, while numbers of native wandering spiders (the native ecological homologues of Cheiracanthium spiders) decreased. Dispersal limitation and strong habitat preferences may have prevented native wandering spiders from establishing far from the vineyard edge. Exotic Cheiracanthium spiders, in contrast, may possess specific adaptations to vineyards or to a wide range of habitats. Results suggest that the ecosystem services provided by intact natural habitat may be limited in agricultural landscapes that are dominated by invasive species.

The Adolescent Condition in Thomas Hardy's The Woodlanders.

Science.gov (United States)

Nunan, Rosanna

In The Woodlanders, Hardy examines the intersections between adolescence as scientific fact and adolescence as utilitarian economic construction. Hardy posits that the emergence of adolescence as a social category provides an opportunity for further, excessive control of young women in a patriarchal society when science is taken at its word, but, paradoxically, also opens up a space for a new kind of freedom and rebellion when the adolescent condition of nineteenth-century scientific theorists is seized for the very subversive qualities which the Victorians oppose.

Goldspotted oak borer: Field identification guide

Science.gov (United States)

S. Hishinuma; T.W. Coleman; M.L. Flint; S.J. Seybold

2011-01-01

The goldspotted oak borer (GSOB), Agrilus auroguttatus (Coleoptera: Buprestidae), is a flatheaded borer new to California that poses a significant threat to oak trees. The pest is native to southeastern Arizona, although a related species occurs in southern Mexico and northern Guatemala. GSOB was first collected and identified in California in 2004 in San Diego County...

Argan woodlands in South Morocco as an area of conflict between degradation and sustainable land use

Science.gov (United States)

Kirchhoff, Mario; Kagermeier, Andreas; Ries, Johannes B.

2016-04-01

The Argan woodlands are endemic for South Morocco and prone to degradation through expanding and intensifying agriculture and overgrazing. Unvegetated areas extend further due to degradation of soil and vegetation. Here infiltration is less than on vegetated areas, while runoff and soil erosion increase. The sale of the highly valuable oil, gained from the seeds of the argan tree, can be seen as an economic alternative for the region and a chance of survival for the argan woodlands. With the introduction of women's cooperatives for the production and sale of the oil, the Gesellschaft für Technische Zusammenarbeit (GTZ, Association for Technical Cooperation) hoped to halt argan degradation from 1995 to 2002. The effects of this approach shall be studied in a proposed DFG-project. The erosion gradient between soils under canopy cover and intertree areas in varying stages of degradation will be at the center of the analysis. Insight into onsite and offsite degradation shall be gained through the measurement of runoff and erosion rates, which lead to rill and gully erosion downslope. Measurements of soil chemical and physical properties might also help indicate when an argan woodland can be classified as natural. Furthermore to be studied are the effects of the new found value of the Argan woodlands among the local population with focus on regional tourism and a possible reduction of grazing pressure. Sustainable soil management in combination with the needs of the local population is essential for a sustainable land use in the region.

Convergence of tree water use within an arid-zone woodland.

Science.gov (United States)

O'Grady, A P; Cook, P G; Eamus, D; Duguid, A; Wischusen, J D H; Fass, T; Worldege, D

2009-07-01

We examined spatial and temporal patterns of tree water use and aspects of hydraulic architecture in four common tree species of central Australia--Corymbia opaca, Eucalyptus victrix, E. camaldulensis and Acacia aneura--to better understand processes that constrain water use in these environments. These four widely distributed species occupy contrasting niches within arid environments including woodlands, floodplains and riparian environments. Measurements of tree water use and leaf water potential were made at two sites with contrasting water table depths during a period of high soil water availability following summer rainfall and during a period of low soil water availability following 7 months of very little rainfall during 2007. There were significant differences in specific leaf area (SLA), sapwood area to leaf area ratios and sapwood density between species. Sapwood to leaf area ratio increased in all species from April to November indicating a decline in leaf area per unit sapwood area. Despite very little rainfall in the intervening period three species, C. opaca, E. victrix and E. camaldulensis maintained high leaf water potentials and tree water use during both periods. In contrast, leaf water potential and water use in the A. aneura were significantly reduced in November compared to April. Despite contrasting morphology and water use strategies, we observed considerable convergence in water use among the four species. Wood density in particular was strongly related to SLA, sapwood area to leaf area ratios and soil to leaf conductance, with all four species converging on a common relationship. Identifying convergence in hydraulic traits can potentially provide powerful tools for scaling physiological processes in natural ecosystems.

Estimating mast production: an evaluation of visual surveys and comparison with seed traps using white oaks

Science.gov (United States)

Roger W. Perry; Ronald E. Thill

1999-01-01

Perry and Thill compared five types of visual mast surveyed with seed trap data from 105 white oaks (Quercus alba L.) during 1996-1997 in the Ouachita Mountains of Arkansas. They also evaluated these visual survey methods for their usefulness in detecting differences in acorn density among areas. Indices derived from all five methods were highly...

A guide for evaluating the adequacy of oak advance reproduction.

Science.gov (United States)

Ivan L. Sander; Paul S. Johnson; Richard F. Watt

1976-01-01

Gives instructions for conducting an inventory of oak advance reproduction prior to final harvest cutting to evaluate the potential for successful oak reproduction in new stands. The potential for oak stump sprouting is also considered.

Forest stand dynamics and sudden oak death: Mortality in mixed-evergreen forests dominated by coast live oak

Science.gov (United States)

L.B. Brown; B. Allen-Diaz

2009-01-01

Sudden oak death (SOD), caused by the recently discovered non-native invasive pathogen, Phytophthora ramorum, has already killed tens of thousands of native coast live oak and tanoak trees in California. Little is known of potential short and long term impacts of this novel plant–pathogen interaction on forest structure and composition. Coast live...

Evaluation of spectral light management on growth of container-grown willow oak, nuttall oak and summer red maple

Science.gov (United States)

Plant response to blue, red, gray or black shade cloth was evaluated with willow oak (Quercus phellos L.), Nuttall oak (Quercus nuttallii Palmer, Nuttall) and Summer Red maple (Acer rubrum L. ‘Summer Red’) liners. Light transmitted through the colored shade cloth had no influence on germination of ...

Long-term trends in coast live oak and tanoak stands affected by Phytophthora ramorum canker (Sudden Oak Death)

Science.gov (United States)

Tedmund J. Swiecki; Elizabeth Bernhardt

2010-01-01

Permanent plots were established in 2000 to examine how tree and site factors affect risk of Phytophthora ramorum stem canker (sudden oak death [SOD]) and determine how affected stands change over time due to disease. P. ramorum canker was prevalent in the sampled coast live oak (Quercus agrifolia) or...

Limits to understory plant restoration following fuel-reduction treatments in a piñon-juniper woodland.

Science.gov (United States)

Redmond, Miranda D; Zelikova, Tamara J; Barger, Nichole N

2014-11-01

National fuel-reduction programs aim to reduce the risk of wildland fires to human communities and to restore forest and rangeland ecosystems to resemble their historical structure, function, and diversity. There are a number of factors, such as seed bank dynamics, post-treatment climate, and herbivory, which determine whether this latter goal may be achieved. Here, we examine the short-term (2 years) vegetation response to fuel-reduction treatments (mechanical mastication, broadcast burn, and pile burn) and seeding of native grasses on understory vegetation in an upland piñon-juniper woodland in southeast Utah. We also examine how wildlife herbivory affects the success of fuel-reduction treatments. Herbaceous cover increased in response to fuel-reduction treatments in all seeded treatments, with the broadcast burn and mastication having greater increases (234 and 160 %, respectively) in herbaceous cover than the pile burn (32 %). In the absence of seeding, herbaceous cover only increased in the broadcast burn (32 %). Notably, fuel-reduction treatments, but not seeding, strongly affected herbaceous plant composition. All fuel-reduction treatments increased the relative density of invasive species, especially in the broadcast burn, which shifted the plant community composition from one dominated by perennial graminoids to one dominated by annual forbs. Herbivory by wildlife reduced understory plant cover by over 40 % and altered plant community composition. If the primary management goal is to enhance understory cover while promoting native species abundance, our study suggests that mastication may be the most effective treatment strategy in these upland piñon-juniper woodlands. Seed applications and wildlife exclosures further enhanced herbaceous cover following fuel-reduction treatments.

Beyond cool: adapting upland streams for climate change using riparian woodlands.

Science.gov (United States)

Thomas, Stephen M; Griffiths, Siân W; Ormerod, Steve J

2016-01-01

Managed adaptation could reduce the risks of climate change to the world's ecosystems, but there have been surprisingly few practical evaluations of the options available. For example, riparian woodland is advocated widely as shade to reduce warming in temperate streams, but few studies have considered collateral effects on species composition or ecosystem functions. Here, we use cross-sectional analyses at two scales (region and within streams) to investigate whether four types of riparian management, including those proposed to reduce potential climate change impacts, might also affect the composition, functional character, dynamics and energetic resourcing of macroinvertebrates in upland Welsh streams (UK). Riparian land use across the region had only small effects on invertebrate taxonomic composition, while stable isotope data showed how energetic resources assimilated by macroinvertebrates in all functional guilds were split roughly 50:50 between terrestrial and aquatic origins irrespective of riparian management. Nevertheless, streams draining the most extensive deciduous woodland had the greatest stocks of coarse particulate matter (CPOM) and greater numbers of 'shredding' detritivores. Stream-scale investigations showed that macroinvertebrate biomass in deciduous woodland streams was around twice that in moorland streams, and lowest of all in streams draining non-native conifers. The unexpected absence of contrasting terrestrial signals in the isotopic data implies that factors other than local land use affect the relative incorporation of allochthonous subsidies into riverine food webs. Nevertheless, our results reveal how planting deciduous riparian trees along temperate headwaters as an adaptation to climate change can modify macroinvertebrate function, increase biomass and potentially enhance resilience by increasing basal resources where cover is extensive (>60 m riparian width). We advocate greater urgency in efforts to understand the ecosystem

Glade/woodland restoration in the St. Francis Mountain Bird Conservation Area

Science.gov (United States)

David A. Hasenbeck

2007-01-01

The Missouri Department of Conservation (MDC), the Missouri Department of Natural Resources, the U.S. Forest Service, and American Bird Conservancy, share goals to restore and manage high quality glade, savanna, and woodland habitats within the Saint Francis Bird Conservation Area. The partnership endeavors to maintain and enhance an ecosystem with native glade and...

Burning in Banksia Woodlands: How Does the Fire-Free Period Influence Reptile Communities?

Science.gov (United States)

Valentine, Leonie E.; Reaveley, Alice; Johnson, Brent; Fisher, Rebecca; Wilson, Barbara A.

2012-01-01

Fire is an important management tool for both hazard reduction burning and maintenance of biodiversity. The impact of time since last fire on fauna is an important factor to understand as land managers often aim for prescribed burning regimes with specific fire-free intervals. However, our current understanding of the impact of time since last fire on fauna is largely unknown and likely dependent on vegetation type. We examined the responses of reptiles to fire age in banksia woodlands, and the interspersed melaleuca damplands among them, north of Perth, Western Australia, where the current prescribed burning regime is targeting a fire-free period of 8–12 years. The response of reptiles to fire was dependent on vegetation type. Reptiles were generally more abundant (e.g. Lerista elegans and Ctenophorus adelaidensis) and specious in banksia sites. Several species (e.g. Menetia greyii, Cryptoblepharus buchananii) preferred long unburnt melaleuca sites (>16 years since last fire, YSLF) compared to recently burnt sites (16 YSLF). The terrestrial dragon C. adelaidensis and the skink Morethia obscura displayed a strong response to fire in banksia woodlands only. Highest abundances of the dragon were detected in the recently burnt (35 YSLF) banksia woodlands, while the skink was more abundant in older sites. Habitats from a range of fire ages are required to support the reptiles we detected, especially the longer unburnt (>16 YSLF) melaleuca habitat. Current burning prescriptions are reducing the availability of these older habitats. PMID:22496806

Floodplain forest succession reveals fluvial processes: A hydrogeomorphic model for temperate riparian woodlands.

Science.gov (United States)

Egger, Gregory; Politti, Emilio; Lautsch, Erwin; Benjankar, Rohan; Gill, Karen M; Rood, Stewart B

2015-09-15

River valley floodplains are physically-dynamic environments where fluvial processes determine habitat gradients for riparian vegetation. These zones support trees and shrubs whose life stages are adapted to specific habitat types and consequently forest composition and successional stage reflect the underlying hydrogeomorphic processes and history. In this study we investigated woodland vegetation composition, successional stage and habitat properties, and compared these with physically-based indicators of hydraulic processes. We thus sought to develop a hydrogeomorphic model to evaluate riparian woodland condition based on the spatial mosaic of successional phases of the floodplain forest. The study investigated free-flowing and dam-impacted reaches of the Kootenai and Flathead Rivers, in Idaho and Montana, USA and British Columbia, Canada. The analyses revealed strong correspondence between vegetation assessments and metrics of fluvial processes indicating morphodynamics (erosion and shear stress), inundation and depth to groundwater. The results indicated that common successional stages generally occupied similar hydraulic environments along the different river segments. Comparison of the spatial patterns between the free-flowing and regulated reaches revealed greater deviation from the natural condition for the braided channel segment than for the meandering segment. This demonstrates the utility of the hydrogeomorphic approach and suggests that riparian woodlands along braided channels could have lower resilience than those along meandering channels and might be more vulnerable to influences such as from river damming or climate change. Copyright © 2015 Elsevier Ltd. All rights reserved.

Burning in banksia woodlands: how does the fire-free period influence reptile communities?

Directory of Open Access Journals (Sweden)

Leonie E Valentine

Full Text Available Fire is an important management tool for both hazard reduction burning and maintenance of biodiversity. The impact of time since last fire on fauna is an important factor to understand as land managers often aim for prescribed burning regimes with specific fire-free intervals. However, our current understanding of the impact of time since last fire on fauna is largely unknown and likely dependent on vegetation type. We examined the responses of reptiles to fire age in banksia woodlands, and the interspersed melaleuca damplands among them, north of Perth, Western Australia, where the current prescribed burning regime is targeting a fire-free period of 8-12 years. The response of reptiles to fire was dependent on vegetation type. Reptiles were generally more abundant (e.g. Lerista elegans and Ctenophorus adelaidensis and specious in banksia sites. Several species (e.g. Menetia greyii, Cryptoblepharus buchananii preferred long unburnt melaleuca sites (>16 years since last fire, YSLF compared to recently burnt sites (16 YSLF. The terrestrial dragon C. adelaidensis and the skink Morethia obscura displayed a strong response to fire in banksia woodlands only. Highest abundances of the dragon were detected in the recently burnt (35 YSLF banksia woodlands, while the skink was more abundant in older sites. Habitats from a range of fire ages are required to support the reptiles we detected, especially the longer unburnt (>16 YSLF melaleuca habitat. Current burning prescriptions are reducing the availability of these older habitats.

Accelerating oak air drying by presurfacing

Science.gov (United States)

W. T. Simpson; R. C. Baltes

1972-01-01

A comparison was made between the air-drying rates of rough and presurfaced northern red oak and white oak. In both species, the presurfaced material was about 1/8 inch thinner than the rough material and dried faster than the rough material. The reduction in drying time depends on the method of analyzing the drying curves, but is slightly less than 10 percent.

Wine evolution and spatial distribution of oxygen during storage in high-density polyethylene tanks.

Science.gov (United States)

del Alamo-Sanza, María; Laurie, V Felipe; Nevares, Ignacio

2015-04-01

Porous plastic tanks are permeable to oxygen due to the nature of the polymers with which they are manufactured. In the wine industry, these types of tanks are used mainly for storing wine surpluses. Lately, their use in combination with oak pieces has also been proposed as an alternative to mimic traditional barrel ageing. In this study, the spatial distribution of dissolved oxygen in a wine-like model solution, and the oxygen transfer rate (OTR) of high-density polyethylene tanks (HDPE), was analysed by means of a non-invasive opto-luminescence detector. Also, the chemical and sensory evolution of red wine, treated with oak pieces, and stored in HDPE tanks was examined and compared against traditional oak barrel ageing. The average OTR calculated for these tanks was within the commonly accepted amounts reported for new barrels. With regards to wine evolution, a number of compositional and sensory differences were observed between the wines aged in oak barrels and those stored in HDPE tanks with oak barrel alternatives. The use of HDPE tanks in combination with oak wood alternatives is a viable alternative too for ageing wine. © 2014 Society of Chemical Industry.

The Woodlands: Una forma diferente de gobernar

Directory of Open Access Journals (Sweden)

Raquel Insa-Ciriza

2010-06-01

Full Text Available The Woodlands (Texas es uno de los mejores ejemplos de éxito de los partenariados público-privados entre el Departamento de Urbanismo y Vivienda Americano (Department of Housing and Urban Development, US - HUD y la empresa privada. The Woodlands, que fue creada como una «Nueva Ciudad» por la compañía Mitchell Energy & Development Corporation, ha ido creciendo y creando una masa crítica de residentes, trabajadores, su propio sentido de comunidad y lo más importante, su propia forma de gobierno. Es el único caso en Estados Unidos de ciudad gobernada por asociaciones privadas. Estas asociaciones, representadas por un Consejo de Administración, proveen la mayoría de los servicios públicos a los ciudadanos. En este artículo se muestra lo que llamo «complicidad ciudadana» basada en lo que el Nuevo Servicio Público define como gobierno basado en la comunidad. Ellos no están reinventando ninguna clase de gobierno, lo que están haciendo es crear una nueva forma de gobierno en la que los ciudadanos prefieren tomar el mando que servir. El estudio del caso que muestro nos ayuda a entender cómo una mayor participación de los ciudadanos en las tareas de la administración local puede hacer disminuir visiblemente el poder del promotor en el desarrollo de una Nueva Ciudad. Esta complicidad ciudadana se traduce en términos de implicación de los miembros de la comunidad en el crecimiento y en el Gobierno de la ciudad

Phylogeographical analysis of mtDNA data indicates postglacial expansion from multiple glacial refugia in woodland caribou (Rangifer tarandus caribou.

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Cornelya F C Klütsch

Full Text Available Glacial refugia considerably shaped the phylogeographical structure of species and may influence intra-specific morphological, genetic, and adaptive differentiation. However, the impact of the Quaternary ice ages on the phylogeographical structure of North American temperate mammalian species is not well-studied. Here, we surveyed ~1600 individuals of the widely distributed woodland caribou (Rangifer tarandus caribou using mtDNA control region sequences to investigate if glacial refugia contributed to the phylogeographical structure in this subspecies. Phylogenetic tree reconstruction, a median-joining network, and mismatch distributions supported postglacial expansions of woodland caribou from three glacial refugia dating back to 13544-22005 years. These three lineages consisted almost exclusively of woodland caribou mtDNA haplotypes, indicating that phylogeographical structure was mainly shaped by postglacial expansions. The putative centres of these lineages are geographically separated; indicating disconnected glacial refugia in the Rocky Mountains, east of the Mississippi, and the Appalachian Mountains. This is in congruence with the fossil record that caribou were distributed in these areas during the Pleistocene. Our results suggest that the last glacial maximum substantially shaped the phylogeographical structure of this large mammalian North American species that will be affected by climatic change. Therefore, the presented results will be essential for future conservation planning in woodland caribou.

Population diversity and evidence of introgression among the black oaks of California

Science.gov (United States)

Richard S. Dodd; Nasser Kashani; Zara Afzal-Rafii

2002-01-01

The black oaks of California include 4 tree species (California black oak, coast live oak, Shreve oak, interior live oak) that are known to hybridize. Complex patterns of population variation within each species are likely to result from these hybrid combinations and from subsequent introgressions. We have been studying population variation using biochemical and...

Estimating forest and woodland aboveground biomass using active and passive remote sensing

Science.gov (United States)

Wu, Zhuoting; Dye, Dennis G.; Vogel, John M.; Middleton, Barry R.

2016-01-01

Aboveground biomass was estimated from active and passive remote sensing sources, including airborne lidar and Landsat-8 satellites, in an eastern Arizona (USA) study area comprised of forest and woodland ecosystems. Compared to field measurements, airborne lidar enabled direct estimation of individual tree height with a slope of 0.98 (R2 = 0.98). At the plot-level, lidar-derived height and intensity metrics provided the most robust estimate for aboveground biomass, producing dominant species-based aboveground models with errors ranging from 4 to 14Mg ha –1 across all woodland and forest species. Landsat-8 imagery produced dominant species-based aboveground biomass models with errors ranging from 10 to 28 Mg ha –1. Thus, airborne lidar allowed for estimates for fine-scale aboveground biomass mapping with low uncertainty, while Landsat-8 seems best suited for broader spatial scale products such as a national biomass essential climate variable (ECV) based on land cover types for the United States.

Design assessment for the Bethel Valley FFA Upgrades at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1995-09-01

This report describes the proposed upgrades to Building 3025 and the Evaporator Area at Oak Ridge National Laboratory. Design assessments, specifications and drawings are provided. Building 3025 is a general purpose research facility utilized by the Materials and Ceramics Division to conduct research on irradiated materials. The Evaporator Area, building 2531, serves as the collection point for all low-level liquid wastes generated at the Oak Ridge National Laboratory

Variability in carbon dioxide fluxes for dense urban, suburban and woodland environments in southern England

Science.gov (United States)

Ward, Helen; Kotthaus, Simone; Grimmond, C. Sue; Bjorkegren, Alex; Wilkinson, Matt; Morrison, Will; Evans, Jon; Morison, James; Christen, Andreas

2014-05-01

The net exchange of carbon dioxide between the surface and atmosphere can be measured using the eddy covariance technique. Fluxes from a dense urban environment (central London), a suburban landscape (Swindon) and a woodland ecosystem (Alice Holt) are compared. All sites are located in southern England and experience similar climatic and meteorological conditions, yet have very different land cover. The signatures of anthropogenic and biogenic processes are explored at various (daily, seasonal and annual) timescales. Particular emphasis is placed on identifying the mixture of controls that determine the flux. In summer, there are clear similarities between the suburban and woodland sites, as the diurnal behaviour is dominated by photosynthetic uptake. In winter, however, vegetation is largely dormant and human activity determines the pattern of fluxes at the urban and suburban sites. Emissions from building heating augment the net release of carbon dioxide in cold months. Road use is a major contributor to the total emissions, and the diurnal cycle in the observed fluxes reflects this: in central London roads are busy throughout the day, whereas in Swindon a double-peaked rush-hour signal is evident. The net exchange of carbon dioxide is estimated for each site and set in context with other studies around the world. Central London has the smallest proportion of vegetation and largest emissions amongst study sites in the literature to date. Although Swindon's appreciable vegetation fraction helps to offset the anthropogenic emissions, even in summertime the 24h total flux is usually positive, indicating carbon release. Comparison of these three sites in a similar region demonstrates the effects of increasing urban density and changing land use on the atmosphere. Findings are relevant in terms of characterising the behaviour of urban surfaces and for quantifying the impact of anthropogenic activities.

Oak Ridge low-level waste disposal facility designs

International Nuclear Information System (INIS)

Van Hoesen, S.D.; Jones, L.S.

1991-01-01

The strategic planning process that culuminates in the identification, selection, construction, and ultimate operation of treatment, storage, and disposal facilities for all types of low-level waste (LLW) generated on the Oak Ridge Reservation (ORR) was conducted under the Low-Level Waste Disposal Development and Demonstration (LLWDDD) Program. This program considered management of various concentrations of short half-life radionuclides generated principally at Oak Ridge National Laboratory (ORNL) and long half-life radionuclides (principally uranium) generated at the Oak Ridge Y-12 Plant and the Oak Ridge K-25 Plant. The LLWDDD Program is still ongoing and involves four phases: (1) alternative identification and evaluation, (2) technology demonstration, (3) limited operational implementation, and (4) full operational implementation. This document provides a discussion of these phases

Radiocaesium - 137 in cultivated and woodland mushrooms

International Nuclear Information System (INIS)

Stankovic, S.; Stankovic, A.

1997-01-01

In the present work the results obtained for activity levels of 137 Cs in samples of cultivated mushrooms (Champignons - Agaricus Silvicola Vitt. Peck.) and woodland fruits ( Chantarelle - Cantarelus Cibarius Fr.; Bollets -Boletus Edulis. ex Fr. and Black Trumpets - Cratarelus Conucopioides) are presented. These samples were collected from 1991 to 1996. Biodiversity of the mushrooms regarding their uptake of radionuclides was found. Thus, the maximum value of 137 Cs activity was found in the sample of dry Bollets 375 Bq/kg in 1993. Moreover, the mean activity level of this species was much higher (126 + - 10 Bq/kg) in 1996. than, levels found in any samples taken from the same environment. (author)

Oak Ridge reservation land-use plan

Energy Technology Data Exchange (ETDEWEB)

Bibb, W. R.; Hardin, T. H.; Hawkins, C. C.; Johnson, W. A.; Peitzsch, F. C.; Scott, T. H.; Theisen, M. R.; Tuck, S. C.

1980-03-01

This study establishes a basis for long-range land-use planning to accommodate both present and projected DOE program requirements in Oak Ridge. In addition to technological requirements, this land-use plan incorporates in-depth ecological concepts that recognize multiple uses of land as a viable option. Neither environmental research nor technological operations need to be mutually exclusive in all instances. Unique biological areas, as well as rare and endangered species, need to be protected, and human and environmental health and safety must be maintained. The plan is based on the concept that the primary use of DOE land resources must be to implement the overall DOE mission in Oak Ridge. This document, along with the base map and overlay maps, provides a reasonably detailed description of the DOE Oak Ridge land resources and of the current and potential uses of the land. A description of the land characteristics, including geomorphology, agricultural productivity and soils, water courses, vegetation, and terrestrial and aquatic animal habitats, is presented to serve as a resource document. Essentially all DOE land in the Oak Ridge area is being fully used for ongoing DOE programs or has been set aside as protected areas.

Design, implementation, and analysis methods for the National Woodland Owner Survey

Science.gov (United States)

Brett J. Butler; Earl C. Leatherberry; Michael S. Williams; Michael S. Williams

2005-01-01

The National Woodland Owner Survey (NWOS) is conducted by the USDA Forest Service, Forest Inventory and Analysis program to increase our understanding of private forest-land owners in the United States. The information is intended to help policy makers, resource managers, and others interested in the forest resources of the United States better understand the social...

Inventories of fallout {sup 21}Pb and {sup 137}Cs radionuclides in moorland and woodland soils around Edinburgh urban area (UK)

Energy Technology Data Exchange (ETDEWEB)

Likuku, A.S. [School of Physics, University of Edinburgh, James Clerk Maxwell Building, King' s Buildings, Mayfield Road, Edinburgh EH9 3JZ (United Kingdom)]. E-mail: alikuku@temo.bca.bw; Branford, D. [School of Physics, University of Edinburgh, James Clerk Maxwell Building, King' s Buildings, Mayfield Road, Edinburgh EH9 3JZ (United Kingdom); Fowler, D. [Centre for Ecology and Hydrology, Edinburgh, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Weston, K.J. [School of GeoSciences, University of Edinburgh, James Clerk Maxwell Building, King' s Buildings, Mayfield Road, Edinburgh EH9 3JZ (United Kingdom)

2006-07-01

Inventories of fallout {sup 21}Pb and {sup 137}Cs have been measured in moorland and woodland soils around the Edinburgh urban area, using a high purity germanium detector. The {sup 21}Pb inventories in moorland soils were relatively uniform, with a mean value of 2520 {+-} 270 Bq m{sup -2}. The mean {sup 137}Cs inventory in moorland soils varied greatly from 1310 to 2100 Bq m{sup -2}, with a mean value of 1580 {+-} 310 Bq m{sup -2}. The variability was ascribed mainly to the non-uniform distribution of fallout Chernobyl {sup 137}Cs. The mean {sup 21}Pb and {sup 137}Cs inventories in woodland canopy soils were found to be 3630 {+-} 380 Bq m{sup -2} and 2510 {+-} 510 Bq m{sup -2}, respectively. At sites for which both moorland and woodland data were available, the mean inventories provided fairly similar average enhancements of (47 {+-} 7)% and (46 {+-} 18)% of {sup 21}Pb and {sup 137}Cs under woodland canopy soils relative to open grassland soils, respectively. The enhancement factors are broadly in line with other independent findings in literature. Enhancement of both {sup 21}Pb and {sup 137}Cs in woodland soils relative to moorland soils is, in part, due to deposition by impaction during air turbulence, wash-off, gravitational settling and deposition during leaf senescence. Results of this study suggest that these processes affect both {sup 21}Pb and {sup 137}Cs carrier aerosols in a similar way.

Mapping Decadal Land Cover Changes in the Woodlands of North Eastern Namibia from 1975 to 2014 Using the Landsat Satellite Archived Data

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Vladimir R. Wingate

2016-08-01

Full Text Available Woodlands and savannahs provide essential ecosystem functions and services to communities. On the African continent, they are widely utilized and converted to subsistence and intensive agriculture or urbanized. This study investigates changes in land cover over four administrative regions of North Eastern Namibia within the Kalahari woodland savannah biome, covering a total of 107,994 km2. Land cover is mapped using multi-sensor Landsat imagery at decadal intervals from 1975 to 2014, with a post-classification change detection method. The dominant change observed was a reduction in the area of woodland savannah due to the expansion of agriculture, primarily in the form of small-scale cereal and pastoral production. More specifically, woodland savannah area decreased from 90% of the study area in 1975 to 83% in 2004, and then increased to 86% in 2014, while agricultural land increased from 6% to 12% between 1975 and 2014. We assess land cover changes in relation to towns, villages, rivers and roads and find most changes occurred in proximity to these. In addition, we find that most land cover changes occur within land designated as communally held, followed by state protected land. With widespread changes occurring across the African continent, this study provides important data for understanding drivers of change in the region and their impacts on the distribution of woodland savannahs.

Impact of the goldspotted oak borer, Agrilus auroguttatus, on the health of coast live oak before and after treatment with two systemic insecticides

Science.gov (United States)

Yigen Chen; Mary L. Flint; Tom W. Coleman; Joseph J. Doccola; Donald M. Grosman; David L. Wood; Steven J. Seybold

2015-01-01

BACKGROUND: The invasive goldspotted oak borer, Agrilus auroguttatus, is threatening the health and survival of oak trees in San Diego County, California. From two sites in the core area of the infestation, we report a 2.5 year investigation of the impact of A. auroguttatus on coast live oak, Quercus agrifolia, before and after treatment with two systemic...

Annual and monthly range fidelity of female boreal woodland caribou in respons to petroleum development

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Boyan V. Tracz

2010-03-01

Full Text Available Petroleum-sector development in northern Alberta, Canada has been implicated as one factor influencing the decline of boreal woodland caribou (Rangifer tarandus caribou. Previous research showed that caribou are farther from petroleum-sector disturbances within their home range than expected. As petroleum development increases, the distance caribou can selectively place themselves relative to industrial disturbance must decrease, because distances between disturbances decrease. Conceptually, the number of local disturbances becomes so large that caribou either abandon their local avoidance behaviour or leave their traditional home range. We evaluated whether an intense petroleum- development event in northern Alberta was sufficient to result in home range abandonment by female woodland caribou. Using well locations as an index of petroleum development, we found that caribou studied from 1992 to 2000 did not change their annual or monthly range fidelity as a function of development intensity. Caribou remained in peatland complexes containing a large number of petroleum-sector disturbances rather than move to new areas, presumably because the risks of dispersing across upland habitat to reach other suitable habitat are high. Such range fidelity may have fitness consequences for woodland caribou if they suffer greater predation in areas where petroleum development is occurring.

The importance of drought-pathogen interactions in driving oak mortality events in the Ozark Border Region

Science.gov (United States)

Wood, Jeffrey D.; Knapp, Benjamin O.; Muzika, Rose-Marie; Stambaugh, Michael C.; Gu, Lianhong

2018-01-01

Forests are expected to become more vulnerable to drought-induced tree mortality owing to rising temperatures and changing precipitation patterns that amplify drought lethality. There is a crucial knowledge gap regarding drought-pathogen interactions and their effects on tree mortality. The objectives of this research were to examine whether stand dynamics and ‘background’ mortality rates were affected by a severe drought in 2012; and to evaluate the importance of drought-pathogen interactions within the context of a mortality event that killed 10.0% and 26.5% of white (Quercus alba L.) and black (Q. velutina Lam.) oak stems, respectively, in a single year. We synthesized (i) forest inventory data (24 years), (ii) 11 years of ecosystem flux data with supporting biological data including predawn leaf water potential and annual forest inventories, (iii) tree-ring analyses of individual white oaks that were alive and ones that died in 2013, and (iv) documentation of a pathogen infection. This forest displayed stand dynamics consistent with expected patterns of decreasing tree density and increasing basal area. Continued basal area growth outpaced mortality implying a net accumulation of live biomass, which was supported by eddy covariance ecosystem carbon flux observations. Individual white and black oaks that died in 2013 displayed historically lower growth with the majority of dead trees exhibiting Biscogniauxia cankers. Our observations point to the importance of event-based oak mortality and that drought-Biscogniauxia interactions are important in shaping oak stand dynamics in this region. Although forest function has not been significantly impaired, these drought-pathogen interactions could amplify mortality under future climate conditions and thus warrant further investigation.

Natural woodland vegetation and plant species richness of the urban open spaces in Gauteng, South Africa

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C.H. Grobler

2002-01-01

Full Text Available It is estimated that approximately 60 % of the world’s population will be living in urban areas by 2025. In Gauteng, the most densely populated province in South Africa, the natural open spaces are continually under threat from development. Vegetation is the most physical representation of the environment on which all animals are ultimately dependent. In order to evaluate an areas potential for development or conservation it is necessary to make a thorough inventory of the plant communities and their associated habitats. A survey of the natural woodlands was undertaken as part of a project describing the vegetation of the natural open spaces within the Gauteng region. Relevés were compiled in 73 stratified random sample plots in selected open spaces within the study area. A TWINSPAN classification, refined by Braun-Blanquet procedures, indicated six woodland communities that can be grouped into two major woodland communities. A classification and description of these communities as well as their species richness are presented. The results indicate that there are still patches of well-preserved natural vegetation within the study area and contribute to the limited knowledge that presently exists for the vegetation of the area.

Sampling and Analysis Plan for White Oak Creek Watershed Remedial Investigation supplemental sampling, Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1996-05-01

This Sampling and Analysis (SAP) presents the project requirements for proposed soil sampling to support the White Oak Creek Remedial Investigation/Feasibility Study at Oak Ridge National Laboratory. During the Data Quality Objectives process for the project, it was determined that limited surface soils sampling is need to supplement the historical environmental characterization database. The primary driver for the additional sampling is the need to identify potential human health and ecological risks at various sites that have not yet proceeded through a remedial investigation. These sites include Waste Area Grouping (WAG)3, WAG 4, WAG 7, and WAG 9. WAG 4 efforts are limited to nonradiological characterization since recent seep characterization activities at the WAG have defined the radiological problem there

Facilitating Oak and Hickory Regeneration in Mature Central Hardwood Forests

Directory of Open Access Journals (Sweden)

Eric J. Holzmueller

2014-12-01

Full Text Available Advanced oak and hickory regeneration is often absent in mature oak-hickory forests in the Central Hardwood Region of the United States. Prescribed fire and thinning, alone and combined, are commonly prescribed silvicultural treatments that are recommended to initiate the regeneration process. This study examined the regeneration response in three mature oak stands following four treatments: (1 thin, (2 burn, (3 thinning and burning, or (4 no treatment (control. Ten years after initial treatment, results indicate that oak and hickory seedlings had greater height and diameter in the thinning and burning treatment compared to the control and that this treatment may help facilitate desirable regeneration in mature oak-hickory forests.

Disentangling woodland caribou movements in response to clearcuts and roads across temporal scales.

Directory of Open Access Journals (Sweden)

David Beauchesne

Full Text Available Although prey species typically respond to the most limiting factors at coarse spatiotemporal scales while addressing biological requirements at finer scales, such behaviour may become challenging for species inhabiting human altered landscapes. We investigated how woodland caribou, a threatened species inhabiting North-American boreal forests, modified their fine-scale movements when confronted with forest management features (i.e. clearcuts and roads. We used GPS telemetry data collected between 2004 and 2010 on 49 female caribou in a managed area in Québec, Canada. Movements were studied using a use--availability design contrasting observed steps (i.e. line connecting two consecutive locations with random steps (i.e. proxy of immediate habitat availability. Although caribou mostly avoided disturbances, individuals nonetheless modulated their fine-scale response to disturbances on a daily and annual basis, potentially compromising between risk avoidance in periods of higher vulnerability (i.e. calving, early and late winter during the day and foraging activities in periods of higher energy requirements (i.e. spring, summer and rut during dusk/dawn and at night. The local context in which females moved was shown to influence their decision to cross clearcut edges and roads. Indeed, although females typically avoided crossing clearcut edges and roads at low densities, crossing rates were found to rapidly increase in greater disturbance densities. In some instance, however, females were less likely to cross edges and roads as densities increased. Females may then be trapped and forced to use disturbed habitats, known to be associated with higher predation risk. We believe that further increases in anthropogenic disturbances could exacerbate such behavioural responses and ultimately lead to population level consequences.

Disentangling woodland caribou movements in response to clearcuts and roads across temporal scales.

Science.gov (United States)

Beauchesne, David; Jaeger, Jochen Ag; St-Laurent, Martin-Hugues

2013-01-01

Although prey species typically respond to the most limiting factors at coarse spatiotemporal scales while addressing biological requirements at finer scales, such behaviour may become challenging for species inhabiting human altered landscapes. We investigated how woodland caribou, a threatened species inhabiting North-American boreal forests, modified their fine-scale movements when confronted with forest management features (i.e. clearcuts and roads). We used GPS telemetry data collected between 2004 and 2010 on 49 female caribou in a managed area in Québec, Canada. Movements were studied using a use--availability design contrasting observed steps (i.e. line connecting two consecutive locations) with random steps (i.e. proxy of immediate habitat availability). Although caribou mostly avoided disturbances, individuals nonetheless modulated their fine-scale response to disturbances on a daily and annual basis, potentially compromising between risk avoidance in periods of higher vulnerability (i.e. calving, early and late winter) during the day and foraging activities in periods of higher energy requirements (i.e. spring, summer and rut) during dusk/dawn and at night. The local context in which females moved was shown to influence their decision to cross clearcut edges and roads. Indeed, although females typically avoided crossing clearcut edges and roads at low densities, crossing rates were found to rapidly increase in greater disturbance densities. In some instance, however, females were less likely to cross edges and roads as densities increased. Females may then be trapped and forced to use disturbed habitats, known to be associated with higher predation risk. We believe that further increases in anthropogenic disturbances could exacerbate such behavioural responses and ultimately lead to population level consequences.

Impacts of communal fuelwood extraction on lidar-estimated biomass patterns of savanna woodlands

CSIR Research Space (South Africa)

Wessels, Konrad J

2012-07-01

Full Text Available Approximately 54% of rural households in South Africa continue to use wood as their main source of energy, mainly for cooking and heating. The provision of biomass by savanna woodlands is thus of considerable value to rural households and therefore...

Effects of breeding habitat (woodland versus urban) and metal pollution on the egg characteristics of great tits (Parus major).

Science.gov (United States)

Hargitai, Rita; Nagy, Gergely; Nyiri, Zoltán; Bervoets, Lieven; Eke, Zsuzsanna; Eens, Marcel; Török, János

2016-02-15

In an urban environment, birds are exposed to metals, which may accumulate in their tissues and cause oxidative stress. Female birds may eliminate these pollutants through depositing them into eggs, thus eggs become suitable bioindicators of pollution. In this study, we aimed to analyse whether eggshell spotting pattern, egg volume, eggshell thickness and egg yolk antioxidant (lutein, tocopherol, retinol and selenium) levels were related to the breeding area (woodland versus urban) and the metal levels in the eggshell of a small passerine species, the great tit (Parus major). In the urban habitat, soil and eggshells contained higher concentrations of metals, and soil calcium level was also higher than that in the woodland. Eggshell spotting intensity and egg volume did not differ between eggs laid in the woodland and the urban park, and these traits were not related to the metal levels of the eggshell, suggesting that these egg characteristics are not sensitive indicators of metal pollution. A more aggregated eggshell spotting distribution indicated a higher Cu concentration of the eggshell. We found that eggshells were thinner in the less polluted woodland habitat, which is likely due to the limited Ca availability of the woodland area. Great tit eggs laid in the urban environment had lower yolk lutein, retinol and selenium concentrations, however, as a possible compensation for these lower antioxidant levels, urban females deposited more tocopherol into the egg yolk. It appears that females from different breeding habitats may provide similar antioxidant protection for their offspring against oxidative damage by depositing different specific dietary antioxidants. Egg yolk lutein and retinol levels showed a negative relationship with lead concentration of the eggshell, which may suggest that lead had a negative impact on the amount of antioxidants available for embryos during development in great tits. Copyright © 2015 Elsevier B.V. All rights reserved.

Genetic hitch-hiking extends the range of coast live oak

Science.gov (United States)

Richard S. Dodd; Zara Afzal-Rafii; Wasima Mayer

2006-01-01

The northernmost range of coast live oak (Quercus agrifolia) is reported from the Ukiah Valley (Mendocino County, California). Here, field observations suggest that hybridization with interior live oak (Q. wislizeni) is important. Elsewhere in northern California, morphology of coast live oak can be highly variable (particularly...

Internal doses in Oak Ridge. The Internet beams

International Nuclear Information System (INIS)

Passchier, W.F.

1997-01-01

A brief overview is given of the information, presented by the Radiation Internal Dose Information Center (RIDIC) of the Oak Ridge Associated Universities in Oak Ridge, TN, USA, via Internet (www.orau.gov/ehsd/ridic.htm)

Contact allergy to oak moss

DEFF Research Database (Denmark)

Bernard, Guillaume; Gimenéz-Arnau, Elena; Rastogi, Suresh Chandra

2003-01-01

In addition to pure synthetic fragrance materials several natural extracts are still in use in the perfume industry. Among them oak moss absolute, prepared from the lichen Evernia prunastri (L.) Arch., is considered a major contact sensitizer and is therefore included in the fragrance mix used...... for diagnosing perfume allergy. The process of preparing oak moss absolute has changed during recent years and, even though several potential sensitizers have been identified from former benzene extracts, its present constituents and their allergenic status are not clear. In the study reported here, we applied...

Hydrologic data summary for the White Oak Watershed at Oak Ridge National Laboratory, Oak Ridge, Tennessee, October 1990--December 1991

International Nuclear Information System (INIS)

Borders, D.M.; Gregory, S.M.; Clapp, R.B.; Frederick, B.J.; Watts, J.A.

1992-06-01

This report summarizes for the 15-month period of October 1990-- December 1991 the available dynamic hydrologic data collected, primarily on the White Oak Creek (WOC) watershed, along with information collected on the surface flow systems that affect the quality or quantity of surface water. The collection of hydrologic data is one component of numerous, ongoing Oak Ridge National Laboratory (ORNL) environmental studies and monitoring programs and is intended to: (1) characterize the quantity and quality of water in the flow systems; (2) assist with the planning and assessment of remedial action activities; and, (3) provide long-term availability of data and quality assurance. Characterization of the hydrology of the WOC watershed is critical for understanding the processes that drive contaminant transport in the watershed. Identification of spatial and temporal trends in hydrologic parameters and mechanisms that affect the movement of contaminants supports the development of interim corrective measures and remedial restoration alternatives. In addition, hydrologic monitoring supports long-term assessment of the effectiveness of remedial actions in limiting the transport of contaminants across Waste Area Grouping (WAG) boundaries and ultimately to the off-site environment. For these reasons, it is of paramount importance to the Environmental Restoration Program (ERP) to collect and report hydrologic data activities that contribute to the Site Investigations component of the ERP. (White Oak Creek is also referred to as ''Whiteoak'' Creek)

75 FR 49524 - Woodland Mills Corporation, Mill Spring, NC; Notice of Affirmative Determination Regarding...

Science.gov (United States)

2010-08-13

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-73,695] Woodland Mills Corporation, Mill Spring, NC; Notice of Affirmative Determination Regarding Application for Reconsideration By application dated July 22, 2010, petitioners requested administrative [[Page 49525

Anti nutritional evaluation of the flour of the nipples of holm oak (quercus ilex) and oak cork (quercus suber) Raw and pressure-sealed

Energy Technology Data Exchange (ETDEWEB)

El Mahi, F. Z.

2009-07-01

The present study contributes to the development of the food potential of the nipples of oak like new resources likely to be exploited on an industrial scale for their use in animal feeds. Our work relates to two species S of nipples of oak, edible, the homl oak and the other fodder one, the oal cork known for their spontaneousness and their vey significant geographical distribution. (Author)

Habitat Predicts Levels of Genetic Admixture in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Viranga Tilakaratna

2017-09-01

Full Text Available Genetic admixture can provide material for populations to adapt to local environments, and this process has played a crucial role in the domestication of plants and animals. The model yeast, Saccharomyces cerevisiae, has been domesticated multiple times for the production of wine, sake, beer, and bread, but the high rate of admixture between yeast lineages has so far been treated as a complication for population genomic analysis. Here, we make use of the low recombination rate at centromeres to investigate admixture in yeast using a classic Bayesian approach and a locus-by-locus phylogenetic approach. Using both approaches, we find that S. cerevisiae from stable oak woodland habitats are less likely to show recent genetic admixture compared with those isolated from transient habitats such as fruits, wine, or human infections. When woodland yeast strains do show recent genetic admixture, the degree of admixture is lower than in strains from other habitats. Furthermore, S. cerevisiae populations from oak woodlands are genetically isolated from each other, with only occasional migration between woodlands and local fruit habitats. Application of the phylogenetic approach suggests that there is a previously undetected population in North Africa that is the closest outgroup to the European S. cerevisiae, including the domesticated Wine population. Careful testing for admixture in S. cerevisiae leads to a better understanding of the underlying population structure of the species and will be important for understanding the selective processes underlying domestication in this economically important species.

Habitat Predicts Levels of Genetic Admixture in Saccharomyces cerevisiae.

Science.gov (United States)

Tilakaratna, Viranga; Bensasson, Douda

2017-09-07

Genetic admixture can provide material for populations to adapt to local environments, and this process has played a crucial role in the domestication of plants and animals. The model yeast, Saccharomyces cerevisiae , has been domesticated multiple times for the production of wine, sake, beer, and bread, but the high rate of admixture between yeast lineages has so far been treated as a complication for population genomic analysis. Here, we make use of the low recombination rate at centromeres to investigate admixture in yeast using a classic Bayesian approach and a locus-by-locus phylogenetic approach. Using both approaches, we find that S. cerevisiae from stable oak woodland habitats are less likely to show recent genetic admixture compared with those isolated from transient habitats such as fruits, wine, or human infections. When woodland yeast strains do show recent genetic admixture, the degree of admixture is lower than in strains from other habitats. Furthermore, S. cerevisiae populations from oak woodlands are genetically isolated from each other, with only occasional migration between woodlands and local fruit habitats. Application of the phylogenetic approach suggests that there is a previously undetected population in North Africa that is the closest outgroup to the European S. cerevisiae , including the domesticated Wine population. Careful testing for admixture in S. cerevisiae leads to a better understanding of the underlying population structure of the species and will be important for understanding the selective processes underlying domestication in this economically important species. Copyright © 2017 Tilakaratna and Bensasson.

Climate change impact on a mixed lowland oak stand in Serbia

Directory of Open Access Journals (Sweden)

Dejan Stojanović

2015-12-01

Full Text Available Climatic changes and bad environmental conditions may lead to forests vitality loss and even mortality. This is the reason why increased sanitary felling operations were performed in mixed oak forests in northern Serbia in 2013 in order to solve the severe dieback which affected some Pedunculate oak (Quercus robur L. and Turkey oak (Quercus cerris L. stands, after the very dry years 2011 and 2012.Dendrochronological techniques were applied to both these oak species collected in a stand, to examine the impact of temperature, precipitation and ground water level on forest growth and investigate the potential causes of the dieback.Differences in tree-ring patterns between surviving and dead trees were not significant according to t-value (from 5.68 to 14.20 and Gleichläufigkeit coefficient (from 76% to 82%, this meaning no distinctive responses of the two ecologically different oak species. As for radial increment, pedunculate and Turkey oak trees showed a similar response to environmental variables in this mixed stand. The Simple Pearson’s correlation analysis, which was conducted, showed that among three basic environmental variables (the mean monthly air temperature, the monthly sum of precipitation and the mean monthly water level, proxy of ground water level, the water level of Danube river in May and the temperature in April were statistically related to the growth of the four tree groups: (i pedunculate oak vital, (ii pedunculate oak dead, (iii Turkey oak vital and (iv Turkey oak dead trees, for the period 1961-2010 (p<0.05, n=60. Similar phenomena had already been observed in the Sava River basin for the growth of pure pedunculate oak forests. The long-term decline of the Danube River water level may be related to climate variations and to the changes of water management, river bed, as well as land-use. Together with the increase of temperature, this decline of the water level, and its potential unavailability in the soil, represents a

Leaf gas exchange in the frankincense tree (Boswellia papyrifera) of African dry woodlands

NARCIS (Netherlands)

Mengistu, T.; Sterck, F.J.; Fetene, M.; Tadesse, W.; Bongers, F.

2011-01-01

A conceptual model was tested for explaining environmental and physiological effects on leaf gas exchange in the deciduous dry tropical woodland tree Boswellia papyrifera (Del.) Hochst. For this species we aimed at (i) understanding diurnal patterns in leaf gas exchange, (ii) exploring cause–effect

Managing an oak decline crisis in Oakville, Ontario: lessons learned

Science.gov (United States)

Peter A. Williams; John W. McNeil; Kurt W. Gottschalk; Robert A. Haack

2013-01-01

The town of Oakville, Ontario, is located along the north shore of Lake Ontario between Toronto and Hamilton. In the fall of 2002, significant oak (Quercus spp.) mortality was observed at Oakville's Iroquois Shoreline Woods Park, an environmentally significant forest remnant noted for its oak-dominated forests. Investigations suggested that oak...

Elemental concentrations in foliage of red maple, red oak, and white oak in relation to atmospheric deposition in Pennsylvania

Science.gov (United States)

D. D. Davis; J. M. Skelly; B. L. Nash

1995-01-01

Foliage was sampled in June and late August-early September in 1988 and 1989 from the outer crowns of codominant red maple (Acer rubrum L.), northern red oak (Quercus rubra L.), and white oak (Q. alba L.) trees in forest stands along an atmospheric deposition gradient in north-central Pennsylvania. Leaf samples...

Differential responses to woodland character and landscape context by cryptic bats in urban environments.

Directory of Open Access Journals (Sweden)

Paul R Lintott

Full Text Available Urbanisation is one of the most dramatic forms of land use change which relatively few species can adapt to. Determining how and why species respond differently to urban habitats is important in predicting future biodiversity loss as urban areas rapidly expand. Understanding how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. Although many bat species are able to exploit human resources, bat species richness generally declines with increasing urbanisation and there is considerable variation in the responses of different bat species to urbanisation. Here, we use acoustic recordings from two cryptic, and largely sympatric European bat species to assess differential responses in their use of fragmented urban woodland and the surrounding urban matrix. There was a high probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Additionally, the probability of recording P. pygmaeus relative to P. pipistrellus was considerably higher in urban woodland interior or edge habitat in contrast to urban grey or non-wooded green space. These results show differential habitat use occurring between two morphologically similar species; whilst the underlying mechanism for this partitioning is unknown it may be driven by competition avoidance over foraging resources. Their differing response to urbanisation indicates the difficulties involved when attempting to assess how adaptable a species is to urbanisation for conservation purposes.

Differential responses to woodland character and landscape context by cryptic bats in urban environments.

Science.gov (United States)

Lintott, Paul R; Bunnefeld, Nils; Minderman, Jeroen; Fuentes-Montemayor, Elisa; Mayhew, Rebekah J; Olley, Lena; Park, Kirsty J

2015-01-01

Urbanisation is one of the most dramatic forms of land use change which relatively few species can adapt to. Determining how and why species respond differently to urban habitats is important in predicting future biodiversity loss as urban areas rapidly expand. Understanding how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. Although many bat species are able to exploit human resources, bat species richness generally declines with increasing urbanisation and there is considerable variation in the responses of different bat species to urbanisation. Here, we use acoustic recordings from two cryptic, and largely sympatric European bat species to assess differential responses in their use of fragmented urban woodland and the surrounding urban matrix. There was a high probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Additionally, the probability of recording P. pygmaeus relative to P. pipistrellus was considerably higher in urban woodland interior or edge habitat in contrast to urban grey or non-wooded green space. These results show differential habitat use occurring between two morphologically similar species; whilst the underlying mechanism for this partitioning is unknown it may be driven by competition avoidance over foraging resources. Their differing response to urbanisation indicates the difficulties involved when attempting to assess how adaptable a species is to urbanisation for conservation purposes.

Fragmented habitats of traditional fruit orchards are important for dead wood-dependent beetles associated with open canopy deciduous woodlands.

Science.gov (United States)

Horak, Jakub

2014-06-01

The conservation of traditional fruit orchards might be considered to be a fashion, and many people might find it difficult to accept that these artificial habitats can be significant for overall biodiversity. The main aim of this study was to identify possible roles of traditional fruit orchards for dead wood-dependent (saproxylic) beetles. The study was performed in the Central European landscape in the Czech Republic, which was historically covered by lowland sparse deciduous woodlands. Window traps were used to catch saproxylic beetles in 25 traditional fruit orchards. The species richness, as one of the best indicators of biodiversity, was positively driven by very high canopy openness and the rising proportion of deciduous woodlands in the matrix of the surrounding landscape. Due to the disappearance of natural and semi-natural habitats (i.e., sparse deciduous woodlands) of saproxylic beetles, orchards might complement the functions of suitable habitat fragments as the last biotic islands in the matrix of the cultural Central European landscape.

Oak regeneration potential increased by shelterwood treatments

Science.gov (United States)

Richard C. Schlesinger; Ivan L. Sander; Kenneth R. Davidson

1993-01-01

In much of the Central Hardwood Forest Region, oak species are not regenerating well, even though large oak trees are common within the existing forests. The shelterwood method has been suggested as a potential tool for establishing and developing advanced regeneration where it is lacking. The 10-yr results from a study of several variants of the shelterwood method...

Detection of soil erosion within pinyon-juniper woodlands using Thematic Mapper (TM) satellite data

Science.gov (United States)

Price, Kevin P.; Ridd, Merrill K.

1991-01-01

The sensitivity of Landsat TM data for detecting soil erosion within pinyon-juniper woodlands, and the potential of the spectral data for assigning the universal soil loss equation (USLE) crop managemnent (C) factor to varying cover types within the woodlands are assessed. Results show greatly accelerated rates of soil erosion on pinyon-juniper sites. Percent cover by pinyon-juniper, total soil-loss, and total nonliving ground cover accounted for nearly 70 percent of the variability in TM channels 2, 3, 4, and 5. TM spectral data were consistently better predictors of soil erosion than the biotic and abiotic field variables. Satellite data were more sensitive to vegetation variation than the USLE C factor, and USLE was found to be a poor predictor of soil loss on pinyon-juniper sites. A new string-to-ground soil erosion prediction technique is introduced.

Flood tolerance of oak seedlings from bottomland and upland sites

Science.gov (United States)

Michael P. Walsh; Jerry Van Sambeek; Mark Coggeshall; David. Gwaze

2009-01-01

Artificial regeneration of oak species in floodplains presents numerous challenges because of the seasonal flooding associated with these areas. Utilizing not only flood-tolerant oak species, but also flood tolerant seed sources of the oak species, may serve to enhance seedling survival and growth rates. Despite the importance of these factors to hardwood forest...

The influence of canopy strata on remotely sensed observations of savanna-woodlands

International Nuclear Information System (INIS)

Fuller, D.O.; Prince, S.D.; Astle, W.L.

1997-01-01

Upwelling radiance from savanna woodlands may originate from two separate layers: (1) the field layer, which is a mixture of soil, litter and herbs, and (2) the tree layer composed of woody parts and leaves. Unless detailed field data are available for a particular savanna location, it is unknown how the individual layers may influence the red and near-infrared signals and whether radiative interactions between layers are important. We employed an existing radiative transfer model (SAIL) in conjunction with a simple, single-scattering model to analyse the variation in Advanced Very High Resolution Radiometer (AVHRR) channel 1 and 2 response as well as NDVI for savanna-woodland vegetation in eastern Zambia. Linear fits between predicted and observed values of reflectance and NDVI were significant ( p 0.05) in the red and in NDVI, however, the model failed to explain a high proportion of the variation in near-infrared. Red and NDVI in sites where tree cover was high were also poorly modelled, which suggests that multiple interactions between canopy layers make a single-scattering model unreliable, particularly in the near-infrared. Modelled results were also compared to aircraft radiometer measurements provided by the integrated camera and radiometer instrument (ICAR). Simulations parameterized with field data suggest that the model may be used to infer tree and field layer influences at different points during the seasonal cycle. Results also suggest that the field layer dominated the signal in our savanna woodland sites throughout most points of the seasonal cycle, which is consistent with other canopy radiative-transfer studies. Simulations indicated that the tree layer was a relatively more important component of NDVI during the dry season when the field layer was largely senescent, accounting for 20-40 per cent of the satellite signal. (author)

Transpiration of Eucalyptus woodlands across a natural gradient of depth-to-groundwater.

Science.gov (United States)

Zolfaghar, Sepideh; Villalobos-Vega, Randol; Zeppel, Melanie; Cleverly, James; Rumman, Rizwana; Hingee, Matthew; Boulain, Nicolas; Li, Zheng; Eamus, Derek

2017-07-01

Water resources and their management present social, economic and environmental challenges, with demand for human consumptive, industrial and environmental uses increasing globally. However, environmental water requirements, that is, the allocation of water to the maintenance of ecosystem health, are often neglected or poorly quantified. Further, transpiration by trees is commonly a major determinant of the hydrological balance of woodlands but recognition of the role of groundwater in hydrological balances of woodlands remains inadequate, particularly in mesic climates. In this study, we measured rates of tree water-use and sapwood 13C isotopic ratio in a mesic, temperate Eucalypt woodland along a naturally occurring gradient of depth-to-groundwater (DGW), to examine daily, seasonal and annual patterns of transpiration. We found that: (i) the maximum rate of stand transpiration was observed at the second shallowest site (4.3 m) rather than the shallowest (2.4 m); (ii) as DGW increased from 4.3 to 37.5 m, stand transpiration declined; (iii) the smallest rate of stand transpiration was observed at the deepest (37.5 m) site; (iv) intrinsic water-use efficiency was smallest at the two intermediate DGW sites as reflected in the Δ13C of the most recently formed sapwood and largest at the deepest and shallowest DGW sites, reflecting the imposition of flooding at the shallowest site and the inaccessibility of groundwater at the deepest site; and (v) there was no evidence of convergence in rates of water-use for co-occurring species at any site. We conclude that even in mesic environments groundwater can be utilized by trees. We further conclude that these forests are facultatively groundwater-dependent when groundwater depth is transpiration is likely to increase significantly at the three shallowest DGW sites. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Consumers’ knowledge of and attitudes toward the role of oak in winemaking

Directory of Open Access Journals (Sweden)

Crump AM

2014-10-01

Full Text Available Anna M Crump,1 Trent E Johnson,1 Susan EP Bastian,1 Johan Bruwer,1,2 Kerry L Wilkinson1 1School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia; 2Ehrenberg-Bass Institute, The University of South Australia, Adelaide, SA, Australia Abstract: Oak plays an important role in the production of some white wines and most red wines. Yet, consumers’ knowledge of the use of oak in winemaking and their preference for oak-related sensory attributes remains unclear. This study examined the knowledge and attitudes of 1,015 Australian wine consumers toward the use of oak in winemaking. Consumers who indicated a liking of oak-aged wines (n=847 were segmented according to their knowledge of the role of oak in wine production. Four distinct consumer clusters were identified, with significantly different preferences for wine sensory attributes and opinions regarding the use of oak alternatives for wine maturation. One segment comprised more knowledgeable consumers, who appreciate and value traditional oak maturation regimes, for which they are willing to pay a premium price. However, a segment comprising less knowledgeable wine consumers was accepting of the use of oak chips, provided wine quality was not compromised. Winemakers can therefore justify the use of oak alternatives to achieve oak-aged wines at lower price points. The outcomes of this study can be used by winemakers to better tailor their wines to the specific needs and expectations of consumers within different segments of the market. Keywords: maturation, segmentation, wine, wine consumers

Population and Habitat Objectives for Avian Conservation in California’s Central Valley Grassland–Oak Savannah Ecosystems

Directory of Open Access Journals (Sweden)

Ryan T. DiGaudio

2017-03-01

Full Text Available http://escholarship.org/uc/item/0dn9f9b4In California’s Central Valley, grassland and oak savannah ecosystems provide multiple economic and social benefits, ecosystem services, and vital bird habitat. There is a growing interest in protecting, restoring, and managing these ecosystems, and the Central Valley Joint Venture (CVJV provides leadership in the formulation of conservation goals and objectives. We defined a long-term goal of protecting, restoring, and managing Central Valley grassland and oak savannah ecosystems so that they are capable of supporting genetically robust, self-sustaining, and resilient wildlife populations. To measure progress toward this goal, we selected a suite of 12 landbird focal species that primarily breed in grasslands and oak savannahs as indicators of the state of these ecosystems on the Central Valley floor (primary focus area and in the Central Valley’s surrounding foothills (secondary focus area. Using data on current densities and habitat extent, we estimated that at least three of the focal species populations in the primary focus area and at least two of the focal species populations in the secondary focus area are currently small (<10,000 individuals and may be vulnerable to extirpation. Furthermore, at least two species appear to have steeply declining population trends. We defined long-term (100-year population objectives for each focal species that we expect to meet the goal of genetically robust, self-sustaining, and resilient populations. We then estimated corresponding short-term (10-year habitat objectives of 4,183 ha of additional grassland and 3,433 ha of additional oak savannah that will be required to make progress toward the long-term objectives. We expect that habitat restoration and enhancement efforts aimed at reaching these long-term conservation objectives will result in improvements to the function of Central Valley grassland and oak savannah ecosystems.

The epidemiology of sudden oak death in Oregon forests

Science.gov (United States)

Ebba K. Peterson

2011-01-01

The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus...

Land Cover Change in Northern Botswana: The Influence of Climate, Fire, and Elephants on Semi-Arid Savanna Woodlands

Directory of Open Access Journals (Sweden)

John Tyler Fox

2017-10-01

Full Text Available Complex couplings and feedback among climate, fire, and herbivory drive short- and long-term patterns of land cover change (LCC in savanna ecosystems. However, understanding of spatial and temporal LCC patterns in these environments is limited, particularly for semi-arid regions transitional between arid and more mesic climates. Here, we use post-classification analysis of Landsat TM (1990, ETM+ (2003, and OLI (2013 satellite imagery to classify and assess net and gross LCC for the Chobe District, a 21,000 km2 area encompassing urban, peri-urban, rural, communally-managed (Chobe Enclave, and protected land (Chobe National Park, CNP, and six protected forest reserves. We then evaluate spatiotemporal patterns of LCC in relation to precipitation, fire detections (MCD14M, 2001–2013 from the Moderate Resolution Imaging Spectroradiometer (MODIS, and dry season elephant (Loxodonta africana aerial survey data (2003, 2006, 2012, 2013. Woodland cover declined over the study period by 1514 km2 (16.2% of initial class total, accompanied by expansion of shrubland (1305 km2, 15.7% and grassland (265 km2, 20.3%. Net LCC differed importantly in protected areas, with higher woodland losses observed in forest reserves compared to the CNP. Loss of woodland was also higher in communally-managed land for the study period, despite gains from 2003–2013. Gross (class changes were characterized by extensive exchange between woodland and shrubland during both time steps, and a large expansion of shrubland into grassland and bare ground from 2003–2013. MODIS active fire detections were highly variable from year to year and among the different protected areas, ranging from 1.8 fires*year−1/km2 in the Chobe Forest Reserve to 7.1 fires*year−1/km2 in the Kasane Forest Reserve Extension. Clustering and timing of dry season fires suggests that ignitions were predominately from anthropogenic sources. Annual fire count was significantly related to total annual rainfall

Big sagebrush in pinyon-juniper woodlands: Using forest inventory and analysis data as a management tool for quantifying and monitoring mule deer habitat

Science.gov (United States)

Chris Witt; Paul L. Patterson

2011-01-01

We used Interior West Forest Inventory and Analysis (IW-FIA) data to identify conditions where pinyon-juniper woodlands provide security cover, thermal cover, and suitable amounts of big sagebrush (Artemisia tridentata spp.) forage to mule deer in Utah. Roughly one quarter of Utah's pinyon-juniper woodlands had a big sagebrush component in their understory....

Unleached Prosopis litter inhibits germination but leached stimulates seedling growth of dry woodland species

NARCIS (Netherlands)

Muturi, Gabriel M.; Poorter, Lourens; Bala, Pauline; Mohren, Godefridus M.J.

2017-01-01

Prosopis chilensis-Prosopis juliflora hybrid (hereinafter referred to as Prosopis species) invade riverine Acacia woodlands and replace indigenous Acacia tortilis through mechanism that are not yet well understood. Therefore, we tested the hypothesis that dense shade and allelopathic effects of

Hydrologic data summary for the White Oak Creek watershed at Oak Ridge National Laboratory, Oak Ridge, Tennessee, January--December 1994

International Nuclear Information System (INIS)

Borders, D.M.; Ziegler, K.S.; Reece, D.K.; Watts, J.A.; Frederick, B.J.; McCalla, W.L.; Pridmore, D.J.

1995-08-01

This report summarizes, for the 12-month period January through December 1994, the available dynamic hydrologic data collected on the White Oak Creek (WOC) watershed as well as information collected on surface flow systems in the surrounding vicinity that may affect the quality or quantity of surface water in the watershed. The collection of hydrologic data is one component of numerous, ongoing Oak Ridge National Laboratory (ORNL) environmental studies and monitoring programs and is intended to characterize the quantity and quality of water in the surface flow system, assist with the planning and assessment of remedial action activities, provide long-term availability of data and quality assurance of these data, and support long-term measures of contaminant fluxes at a spatial scale to provide a comprehensive picture of watershed performance that is commensurate with future remedial actions

Moccasins into Slippers: Woodlands Indian Hats, Bags, and Shoes in Tradition and Transformation.

Science.gov (United States)

Phillips, Ruth B.

1990-01-01

In the mid-nineteenth century, an abrupt transformation occurred in textiles and other art forms of northeastern Woodlands Indians. Trade, tourism, and survival needs sparked changes in materials used and garment types produced, as well as substitution of a new vocabulary of floral imagery for "pagan" iconographic traditions. (SV)

White Oak Creek embayment sediment retention structure: The Oak Ridge model in action

International Nuclear Information System (INIS)

Van Hoesen, S.D.; Kimmel, B.L.; Page, D.G.; Hudson, G.R.; Wilkerson, R.B.; Zocolla, M.

1992-01-01

White Oak Creek is the major surface-water drainage through the Department of Energy (DOE) Oak Ridge National Laboratory (ORNL). Samples taken from the lower portion of the creek revealed high levels of Cesium-137, and lower levels of Cobalt-60 in near-surface sediment. Other contaminants present in the sediment included: lead, mercury, chromium, and PCBS. In October 1990, DOE, US Environmental Protection Agency (EPA), and Tennessee Department of Environment and Conservation (DEC) agreed to initiate a time-critical removal action in accordance with Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) to prevent transport of the contaminated sediments into the Clinch River system. This paper discusses the environmental, regulatory, design, and construction issues that were encountered in conducting the remediation work

Environmental data for the White Oak Creek/White Oak Lake watershed: Environmental Sciences Division publication No. 2779

International Nuclear Information System (INIS)

Sherwood, C.B.; Loar, J.M.

1987-01-01

Oak Ridge National Laboratory (ORNL) is located in the White Oak Creek (WOC) watershed, which drains approximately 16.8 km 2 (6.5 mile 2 ). The waters of WOC are impounded by White Oak Dam at WOC's intersection with White Wing Road (State Route 95), 1.0 km (0.6 mile) upstream from the Clinch River. The resulting White Oak Lake (WOL) is a small, shallow impoundment, whose water level is controlled by a vertical sluice gate that remains in a fixed position during normal operations. White Oak Creek has been utilized for the discharge of treated and untreated wastes from routine operations since the Laboratory's inception. In addition, most of the more recent (1954 to date) liquid and solid low-level-waste disposal operations have been located in the drainage area of WOC. As a federally owned facility, ORNL is required to comply with all existing federal, state, and local environmental regulations regarding waste management. On July 15, 1985, the US Environmental Protection Agency published final rules to incorporate changes in the Resource Conservation and Recovery Act of 1976 that resulted from the passage of the Hazardous and Solid Waste Amendments of 1984. As a part of the rule changes, a new Sect. 3004(u) was added. The new section requires that any facility permit issued after November 8, 1984, include planned corrective actions for all continuing releases of hazardous waste or constituents from any disposal unit at the facility, regardless of when the waste was placed at the disposal unit. This report was prepared to compile existing information on the content and quantity of hazardous substances (both radioactive and nonradioactive) in the WOC/WOL watershed and to provide background information on the geology, hydrology, and ecology of the site for use in planning future remedial actions. 109 refs., 45 figs., 33 tabs

Environmental data for the White Oak Creek/White Oak Lake watershed: Environmental Sciences Division publication No. 2779

Energy Technology Data Exchange (ETDEWEB)

Sherwood, C.B.; Loar, J.M.

1987-01-01

Oak Ridge National Laboratory (ORNL) is located in the White Oak Creek (WOC) watershed, which drains approximately 16.8 km/sup 2/ (6.5 mile/sup 2/). The waters of WOC are impounded by White Oak Dam at WOC's intersection with White Wing Road (State Route 95), 1.0 km (0.6 mile) upstream from the Clinch River. The resulting White Oak Lake (WOL) is a small, shallow impoundment, whose water level is controlled by a vertical sluice gate that remains in a fixed position during normal operations. White Oak Creek has been utilized for the discharge of treated and untreated wastes from routine operations since the Laboratory's inception. In addition, most of the more recent (1954 to date) liquid and solid low-level-waste disposal operations have been located in the drainage area of WOC. As a federally owned facility, ORNL is required to comply with all existing federal, state, and local environmental regulations regarding waste management. On July 15, 1985, the US Environmental Protection Agency published final rules to incorporate changes in the Resource Conservation and Recovery Act of 1976 that resulted from the passage of the Hazardous and Solid Waste Amendments of 1984. As a part of the rule changes, a new Sect. 3004(u) was added. The new section requires that any facility permit issued after November 8, 1984, include planned corrective actions for all continuing releases of hazardous waste or constituents from any disposal unit at the facility, regardless of when the waste was placed at the disposal unit. This report was prepared to compile existing information on the content and quantity of hazardous substances (both radioactive and nonradioactive) in the WOC/WOL watershed and to provide background information on the geology, hydrology, and ecology of the site for use in planning future remedial actions. 109 refs., 45 figs., 33 tabs.

TESTING BAYESIAN ALGORITHMS TO DETECT GENETIC STRUCTURE IN TWO CLOSELY RELATED OAK TAXA

Directory of Open Access Journals (Sweden)

Cristian Mihai Enescu

2013-12-01

Full Text Available The aim of this study was to test the Bayesian algorithm implemented in the software STRUCTURE in order to detect the number of clusters, by using microsatellite data from four oak species. Several assignment models, with or without a priori grouping of individuals to species, were proposed. Better results were obtained by using the sampling location information and when only two taxa were analyzed. Particularly, pedunculate oak and sessile oak formed distinct clusters whatever the assignment model we use. By contrast, no separation between the two oaks from series Lanuginosae was observed. This can be explained, on one hand, by the small sampling size for Italian oak, or by the genetic similarities of the two pubescent oaks, namely Quercus pubescens and Q. virgiliana, on the other hand. Our findings support the hypothesis according which Italian oak is an intraspecific taxonomic unit of pubescent oak.

The effect of nitrogen additions on oak foliage and herbivore communities at sites with high and low atmospheric pollution

International Nuclear Information System (INIS)

Eatough Jones, Michele; Paine, Timothy D.; Fenn, Mark E.

2008-01-01

To evaluate plant and herbivore responses to nitrogen we conducted a fertilization study at a low and high pollution site in the mixed conifer forests surrounding Los Angeles, California. Contrary to expectations, discriminant function analysis of oak herbivore communities showed significant response to N fertilization when atmospheric deposition was high, but not when atmospheric deposition was low. We hypothesize that longer-term fertilization treatments are needed at the low pollution site before foliar N nutrition increases sufficiently to affect herbivore communities. At the high pollution site, fertilization was also associated with increased catkin production and higher densities of a byturid beetle that feeds on the catkins of oak. Leaf nitrogen and nitrate were significantly higher at the high pollution site compared to the low pollution site. Foliar nitrate concentrations were positively correlated with abundance of sucking insects, leafrollers and plutellids in all three years of the study. - Nitrogen additions at sites impacted by air pollution were associated with altered foliar herbivore communities and increased densities of a catkin-feeding beetle on Quercus kellogii

Site descriptions of environmental restoration units at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

Kuhaida, A.J. Jr.; Parker, A.F.

1997-02-01

This report provides summary information on Oak Ridge National Laboratory (ORNL) Environmental Restoration (ER) sites as listed in the Oak Ridge Reservation Federal Facility Agreement (FFA), dated January 1, 1992, Appendix C. The Oak Ridge National Laboratory was built in 1943 as part of the World War II Manhattan Project. The original mission of ORNL was to produce and chemically separate the first gram-quantities of plutonium as part of the national effort to produce the atomic bomb. The current mission of ORNL is to provide applied research and development in support of the U.S. Department of Energy (DOE) programs in nuclear fusion and fission, energy conservation, fossil fuels, and other energy technologies and to perform basic scientific research in selected areas of the physical, life, and environmental sciences. ER is also tasked with clean up or mitigation of environmental impacts resulting from past waste management practices on portions of the approximately 37,000 acres within the Oak Ridge Reservation (ORR). Other installations located within the ORR are the Gaseous Diffusion Plant (K-25) and the Y-12 plant. The remedial action strategy currently integrates state and federal regulations for efficient compliance and approaches for both investigations and remediation efforts on a Waste Area Grouping (WAG) basis. As defined in the ORR FFA Quarterly Report July - September 1995, a WAG is a grouping of potentially contaminated sites based on drainage area and similar waste characteristics. These contaminated sites are further divided into four categories based on existing information concerning whether the data are generated for scoping or remedial investigation (RI) purposes. These areas are as follows: (1) Operable Units (OU); (2) Characterization Areas (CA); (3) Remedial Site Evaluation (RSE) Areas; and (4) Removal Site Evaluation (RmSE) Areas.

Visitor preferences of thinning practice in young even-aged stands of pedunculate oak (Quercus robur L.)

DEFF Research Database (Denmark)

Petucco, Claudio; Jensen, Frank Søndergaard; Meilby, Henrik

2018-01-01

This study compared visitor preferences of forestry professionals across six European countries (Sweden, Denmark, Great Britain, Austria, Romania and Portugal) using a questionnaire survey. The 598 interviewees were asked to rank photographs depicting recently thinned experimental plots in a 13......-year old stand of pedunculate oak (Quercus robur L.) according to the criterion: “Which forest environment do you prefer as a visitor?” The plots represented five different residual stem densities: 7000 (no thinning, very high stem density), 5300 (heavy thinning, high stem density), 1000 (very heavy...... rows, indicating a preference for scenes offering perspective and accessibility. The results indicate a variation of visitor preferences among forestry professionals for different silvicultural regimes. We interpret this in the context of national traditions and forestry paradigms that influence...

The most significant fungi: Agents of wood decay in oak forests of Serbia

Directory of Open Access Journals (Sweden)

Milijašević Tanja

2007-01-01

Full Text Available The most widely distributed oak species in Serbia are Q. petrea (sessile oak, Q. cerris (Turkey oak and Q. frainetto (Hungarian oak and Quercus robur (common oak, and lignicolous fungi are the major agents of wood decay in natural and coppice oak forests. In this research, 33 species of fungi were identified. Eleven species were described, among which the most significant are: Armillaria mellea, Fomes fomentarius, Hypoxylon deustum Laetiporus sulphureus, Lenzites quercina and Phellinus robustus. This paper presents the morphological characteristics of the most significant identified fungi, their distribution, host plants and significance.

Bacteria associated with oak and ash on a TCE-contaminated site: characterization of isolates with potential to avoid evapotranspiration of TCE.

Science.gov (United States)

Weyens, Nele; Taghavi, Safiyh; Barac, Tanja; van der Lelie, Daniel; Boulet, Jana; Artois, Tom; Carleer, Robert; Vangronsveld, Jaco

2009-11-01

Along transects under a mixed woodland of English Oak (Quercus robur) and Common Ash (Fraxinus excelsior) growing on a trichloroethylene (TCE)-contaminated groundwater plume, sharp decreases in TCE concentrations were observed, while transects outside the planted area did not show this remarkable decrease. This suggested a possibly active role of the trees and their associated bacteria in the remediation process. Therefore, the cultivable bacterial communities associated with both tree species growing on this TCE-contaminated groundwater plume were investigated in order to assess the possibilities and practical aspects of using these common native tree species and their associated bacteria for phytoremediation. In this study, only the cultivable bacteria were characterized because the final aim was to isolate TCE-degrading, heavy metal resistant bacteria that might be used as traceable inocula to enhance bioremediation. Cultivable bacteria isolated from bulk soil, rhizosphere, root, stem, and leaf were genotypically characterized by amplified rDNA restriction analysis (ARDRA) of their 16S rRNA gene and identified by 16S rRNA gene sequencing. Bacteria that displayed distinct ARDRA patterns were screened for heavy metal resistance, as well as TCE tolerance and degradation, as preparation for possible future in situ inoculation experiments. Furthermore, in situ evapotranspiration measurements were performed to investigate if the degradation capacity of the associated bacteria is enough to prevent TCE evapotranspiration to the air. Between both tree species, the associated populations of cultivable bacteria clearly differed in composition. In English Oak, more species-specific, most likely obligate endophytes were found. The majority of the isolated bacteria showed increased tolerance to TCE, and TCE degradation capacity was observed in some of the strains. However, in situ evapotranspiration measurements revealed that a significant amount of TCE and its metabolites

Perspectives on cultural values of California oaks

Science.gov (United States)

Paul F. Starrs

2002-01-01

The status and prospects of oaks—those native to California and the many elsewhere—are insufficiently known, despite historical volumes of work done in the past and more ongoing today. That globally there is a blistering diversity of oaks in different environments, and put to distinct uses, is beyond dispute. Less agreed upon, though, is their complex history and the...

Stable carbon isotope analysis of soil organic matter illustrates vegetation change at the grassland/woodland boundary in southeastern Arizona, USA.

Science.gov (United States)

McPherson, G R; Boutton, T W; Midwood, A J

1993-02-01

In southeastern Arizona, Prosopis juliflora (Swartz) DC. and Quercus emoryi Torr. are the dominant woody species at grassland/woodland boundaries. The stability of the grassland/woodland boundary in this region has been questioned, although there is no direct evidence to confirm that woodland is encroaching into grassland or vice versa. We used stable carbon isotope analysis of soil organic matter to investigate the direction and magnitude of vegetation change along this ecotone. δ 13 C values of soil organic matter and roots along the ecotone indicated that both dominant woody species (C 3 ) are recent components of former grasslands (C 4 ), consistent with other reports of recent increases in woody plant abundance in grasslands and savannas throughout the world. Data on root biomass and soil organic matter suggest that this increase in woody plant abundance in grasslands and savannas may increase carbon storage in these ecosystems, with implications for the global carbon cycle.

Estructura y estado de conservación de los bosques de Prosopis flexuosa D.C. (Fabaceae, subfamilia: Mimosoideae en el noreste de Mendoza (Argentina Structure and conservative condition of the Prosopis flexuosa D.C. (Fabaceae, subfamily: Mimosoideae woodlands in northeast Mendoza (Argentina

Directory of Open Access Journals (Sweden)

JUAN AGUSTÍN ALVAREZ

2006-03-01

allowed to find out about the population structure of the Prosopis flexuosa woodlands of the northeast of Mendoza, as well as their sanitary conditions and the management potential. A total of 1,471 Prosopis individuals were sampled in the four most representative woodlands units. The total Prosopis density was as follows: P. flexuosa semi-closed woodland with Atriplex lampa and Lycium tenuispinosum in valleys in-between dunes (Woodland 1: 181 trees ha-1; P. flexuosa open woodland with Trichomaria usillo and Suaeda divaricata in the undulations (Woodland 2: 155 trees ha-1; P. flexuosa open woodland with T. usillo (Woodland 3: 233 trees ha-1, and P. flexuosa open woodland with A. lampa in soft undulations (Woodland 4: 215 trees ha-1. The principal components analysis on the diametric structure grouped the sites surveyed in the different woodland units as per the proportion of individuals with larger basal diameter. The sites from Woodland 1 (larger proportion of big trees, were separated from the sites with a higher proportion of small trees (Woodland 2 and 4. Due to the Prosopis growth habit, the quantity of wood products from these forests is low. Besides P. flexuosa presents in the area a high percentage of individuals with more than two stems, the tree shape is generally decumbent and the bole height is less than a meter. Therefore, the possible use should be done at local scale, taking into account the inclusion of other complementary activities

Distributional record of oak gall wasp (Hymenoptera: Cynipidae ...

African Journals Online (AJOL)

In this survey, oak gall wasp species were collected from the oak forests of Pardanan, Mirabad, Nalas, Sardasht, Hamran and Dar-ghabr in West-Azerbaijan province. The galls occurring on 50 cm sampled branches from four cardinal directions on each tree were counted multiple times throughout the season. Species ...

The importance of herbivore interactions for the dynamics of African savanna woodlands : an hypothesis

NARCIS (Netherlands)

Van de Koppel, J; Prins, HHT

Current hypotheses to explain dynamic transitions between savanna grasslands and woodlands in Africa focus on grazing by elephant or the influence of fire. Using a simple mathematical model, this paper argues that interactions between small herbivores such as impala or buffalo and large herbivores

Vegetation structure characteristics and relationships of Kalahari woodlands and savannas

CSIR Research Space (South Africa)

Privette, JL

2004-03-01

Full Text Available modeling has become widespread (e.g., Potter et al., 1993, 1998; Sellers et al., 1996). Nevertheless, knowledge of vegetation canopy struc- ture remains incomplete in many remote areas, such as sub-Saharan Africa. First, comparatively small changes... 929 460 Colophospermum mopane woodland with patches of Terminalia sericea thicket Harry Oppenheimer Okavango Research Centre; Measurements were 3km east of a permanent flux tower 23.591E Okwa River Crossing, Botswana 22.411S 1089 407 Open Kalahari...

Bird species associated with green ash woodlands in the Slim Buttes, South Dakota

Science.gov (United States)

Robert A. Hodorff; Carolyn Hull Sieg

1986-01-01

In western South Dakota, native deciduous woodlands are uncommon, constituting less than 1% of the total land area (Boldt et al. 1978). The Green Ash/Common Chokecherry (Fraxinus pennsylvanica/Prunus virginiana) habitat type is the major deciduous habitat type in northwestern South Dakota (Hansen and Hoffman 1985). This type occurs in depressions,...

The role of large container seedlings in afforesting oaks in bottomlands

Science.gov (United States)

Daniel C. Dey; John M. Kabrick; Michael Gold

2006-01-01

We planted large container (RPM®) and 1-0 bareroot seedlings of pin oak (Quercus palustris Muenchh.) and swamp white oak (Q. bicolor Willd.) in crop fields in the Missouri River floodplain. We also evaluated the benefits of soil mounding and a grass (Agrostis gigantea Roth) cover crop. RPM®) oak seedlings had significantly greater...

Short-term response of small mammals following oak regeneration silviculture treatments.

Science.gov (United States)

Amy L. Raybuck; Christopher E. Moorman; Christopher S. DePerno; Kevin Gross; Dean M. Simon; Gordon S. Warburton

2012-01-01

Upland, mixed-oak forests in the eastern United States have experienced widespread oak regeneration failure, largely due to cessation of anthropogenic disturbance. Silvicultural practices used to promote advance oak regeneration may affect ground-dwelling mammals. From May to August 2008 (pre-treatment), 2010 (first year post-treatment), and 2011 (second year post-...

Oak woodland conservation as mitigation for roadway improvement

Science.gov (United States)

Park Steiner; Jackson Ford

2015-01-01

East Side Potter Valley (ESPV) Road is a heavily used rural collector road running north/south through the unincorporated area of Mendocino County known as Potter Valley. The roadway is significantly deteriorated and in need of repair and upgrade. The Mendocino County Department of Transportation (MCDOT) road project encompasses approximately 6.4 km of roadway that...

Removal action report on the Building 3001 canal at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-05-01

Oak Ridge National Laboratory (ORNL) is a federal facility managed by Lockheed Martin C, Energy Research, Inc., for the U.S. Department of Energy (DOE). ORNL on the Oak Ridge Reservation in East Tennessee at the Anderson and Roane County lines, approximately 38 km (24 miles) west of Knoxville, Tennessee, and 18 km (11 miles) southwest of downtown Oak Ridge. The Oak Ridge Graphite Reactor and its storage and transfer canal are located in Bldg. 3001 in the approximate center of Waste Area Grouping I in the ORNL main complex. 4:1 The Bldg. 3001 Storage Canal is an L-shaped, underground, reinforced-concrete structure running from the back and below the Graphite Reactor in Bldg. 3001 to a location beneath a hot cell in the adjacent Bldg. 3019. The Graphite Reactor was built in 1943 to produce small quantities of plutonium and was subsequently used to produce other isotopes for medical research before it was finally shut down in 1963. The associated canal was used to transport, under water, spent fuel slugs and other isotopes from the back of the reactor to the adjacent Bldg. 31319 hot cell for further processing. During its operation and years subsequent to operation, the canal's concrete walls and floor became contaminated with radioisotopes from the water.This report documents the activities involved with replacing the canal water with a solid, controlled, low-strength material (CLSM) in response to a Comprehensive Environmental Response, Compensation, and Liability Act non-time-critical removal action

ORLANDO - Oak Ridge Large Neutrino Detector

International Nuclear Information System (INIS)

Bugg, W.; Cohn, H.; Efremenko, Yu.; Fazely, A.; Gabriel, T.; Kamyshkov, Yu.; Plasil, F.; Svoboda, R.

1999-01-01

We discuss a proposal for construction of an Oak Ridge LArge Neutrino DetectOr (ORLANDO) to search for neutrino oscillations at the Spallation Neutron Source (SNS). A 4 MW SNS is proposed to be built at the Oak Ridge National Laboratory with the first stage to be operative around 2006. It will have two target stations, which makes it possible with a single detector to perform a neutrino oscillation search at two different distances. Initial plans for the placement of the detector and the discovery potential of such a detector are discussed

Phase I remedial investigation report of Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Miller, D.E.

1995-07-01

This report presents the activities and findings of the first phase of a three-phase remedial investigation (RI) of Waste Area Grouping (WAG) 2 at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, and updates the scope and strategy for WAG-2-related efforts. WAG 2 contains White Oak Creek (WOC) and its tributaries downstream of the ORNL main plant area, White Oak Lake, White Oak Creek Embayment on the Clinch River, and the associated floodplain and subsurface environment. Water, sediment, soil, and biota in WAG 2 are contaminated and continue to receive contaminants from upgradient WAGs. This report includes field activities completed through October 1992. The remediation of WAG 2 is scheduled to follow the cessation of contaminant input from hydrologically upgradient WAGs. While upgradient areas are being remediated, the strategy for WAG 2 is to conduct a long-term monitoring and investigation program that takes full advantage of WAG 2's role as an integrator of contaminant fluxes from other ORNL WAGs and focuses on four key goals: (1) Implement, in concert with other programs, long-term, multimedia environmental monitoring and tracking of contaminants leaving other WAGs, entering WAG 2, and being transported off-site. (2) Provide a conceptual framework to integrate and develop information at the watershed-level for pathways and processes that are key to contaminant movement, and so support remedial efforts at ORNL. (3) Provide periodic updates of estimates of potential risk (both human health and ecological) associated with contaminants accumulating in and moving through WAG 2 to off-site areas. (4) Support the ORNL Environmental Restoration Program efforts to prioritize, remediate, and verify remedial effectiveness for contaminated sites at ORNL, through long-term monitoring and continually updated risk assessments

Molecular diversity among Turkish oaks ( QUERCUS ) using random ...

African Journals Online (AJOL)

Turkey is one of the most important region of the world according to oak species number and variation. In this study, species belonging to evergreen oaks in Turkey were investigated to solve taxonomic problems and to design the limit of taxa by using random amplified polymorphic DNA (RAPD) data. Here, three species of ...

Oak Ridge Reservation Site Management Plan for the Environmental Restoration Program

Energy Technology Data Exchange (ETDEWEB)

1994-06-01

This site management plan for the Oak Ridge Reservation (ORR) describes the overall approach for addressing environmental contamination problems at the ORR Superfund site located in eastern Tennessee. The ORR consists of three major US Department of Energy (DOE) installations constructed in the early to mid 1940s as research, development, and process facilities in support of the Manhattan Project. In addition to the three installations -- Oak Ridge National Laboratory (ORNL), the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site (formerly the Oak Ridge Gaseous Diffusion Plant) -- the ORR Superfund Site also includes areas outside the installations, land used by the Oak Ridge Associated Universities and waterways that have been contaminated by releases from the DOE installations. To date, {approximately} 400 areas (Appendix A) requiring evaluation have been identified. Cleanup of the ORR is expected to take two to three decades and cost several billion dollars. This site management plan provides a blueprint to guide this complex effort to ensure that the investigation and cleanup activities are carried out in an efficient and cost-effective manner.

Oak Ridge Reservation Site Management Plan for the Environmental Restoration Program

International Nuclear Information System (INIS)

1994-06-01

This site management plan for the Oak Ridge Reservation (ORR) describes the overall approach for addressing environmental contamination problems at the ORR Superfund site located in eastern Tennessee. The ORR consists of three major US Department of Energy (DOE) installations constructed in the early to mid 1940s as research, development, and process facilities in support of the Manhattan Project. In addition to the three installations -- Oak Ridge National Laboratory (ORNL), the Oak Ridge Y-12 Plant, and the Oak Ridge K-25 Site (formerly the Oak Ridge Gaseous Diffusion Plant) -- the ORR Superfund Site also includes areas outside the installations, land used by the Oak Ridge Associated Universities and waterways that have been contaminated by releases from the DOE installations. To date, ∼ 400 areas (Appendix A) requiring evaluation have been identified. Cleanup of the ORR is expected to take two to three decades and cost several billion dollars. This site management plan provides a blueprint to guide this complex effort to ensure that the investigation and cleanup activities are carried out in an efficient and cost-effective manner

Dogwood borer (Lepidoptera: Sesiidae) abundance and seasonal flight activity in apple orchards, urban landscapes, and woodlands in five eastern states.

Science.gov (United States)

Bergh, J C; Leskey, T C; Walgenbach, J F; Klingeman, W E; Kain, D P; Zhang, A

2009-06-01

The relative abundance and seasonal flight activity of dogwood borer, Synanthedon scitula Harris (Lepidoptera: Sesiidae), was measured using weekly records from traps baited with its sex pheromone and deployed in apple orchards, urban landscapes, and native woodland sites in New York, West Virginia, Virginia, North Carolina, and Tennessee in 2005 and 2006. The mean total number of moths captured per site in apple orchards was 3,146 +/- 644 and 3095 +/- 584 SE in 2005 and 2006, respectively, exceeding captures at urban sites by 16 and 13 times and at woodland sites by 210 and 206 times in 2005 and 2006, respectively. Mean total captures at urban sites exceeded those in woodland habitats by 13 and 16 times in 2005 and 2006, respectively. The mean duration (wk) of the flight period did not differ significantly between apple orchards (22.6 +/- 0.6 SE) and urban sites (20.3 +/- 1.2 SE). The onset of flight was somewhat later in New York (around early June) than further south (around early to mid-May), but moth captures continued into October in all states. Captures in apple orchards and at urban sites with higher populations were essentially continuous throughout the flight period, with substantial weekly fluctuations, and tended to show a bimodal pattern with peaks from late May through mid-July and from late August through mid-September. Captures at woodland sites tended to occur predominantly from mid-May through about mid-June and were very sporadic thereafter.

The state of mixed shortleaf pine-upland oak management in Missouri

Science.gov (United States)

Elizabeth M. Blizzard; David R. Larsen; Daniel C. Dey; John M. Kabrick; David Gwaze

2007-01-01

Mixed shortleaf pine-upland oak stands allow flexibility in type and timing of regeneration, release, and harvesting treatments for managers; provide unique wildlife and herbaceous community niches; and increase visual diversity. Most of the research to date focused on growing pure pine or oak stands, with little research on today's need to grow pine-oak mixtures...

Evolution of ellagitannins in Spanish, French, and American oak woods during natural seasoning and toasting.

Science.gov (United States)

Cadahía, E; Varea, S; Muñoz, L; Fernández De Simón, B; García-Vallejo, M C

2001-08-01

The evolution of tannins in Spanish oak heartwood of Quercus robur L., Quercus petraea Liebl.,Quercus pyrenaica Wild., and Quercus faginea Lam. was studied in relation to the processing of wood in barrel cooperage. Their evolution was compared with that of French oak of Q. robur (Limousin, France) and Q. petraea (Allier, France) and American oak of Quercus alba L. (Missouri), which are habitually used in cooperage. Two stages of process were researched: the seasoning of woods during 3 years in natural conditions and toasting. Total phenol and total ellagitannin contents and optical density at 420 nm of wood extracts were determined. The ellagitannins roburins A-E, grandinin, vescalagin, and castalagin were identified and quantified by HPLC, and the molecular weight distribution of ellagitannins was calculated by GPC. During the seasoning process the different ellagitannin concentrations decreased according to the duration of this process and in the same way as those in French and American woods. The toasting process also had an important influence on the ellagitannin composition of wood. Roburins A-E, grandinin, vescalagin, and castalagin decreased during this process in the Spanish wood species, in the same proportion as in the French and American ones. Also, the seasoning and toasting processes lead to qualitative variations in the structure of ellagitannins, especially in the molecular weight distribution, as was evidenced by GPC analysis of their acetylated derivatives.

Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

International Nuclear Information System (INIS)

Loar, J.M.; Adams, S.M.; Allison, L.J.; Blaylock, B.G.; Boston, H.L.; Huston, M.A.; Kimmel, B.L.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.; Walton, B.T.; Kitchings, J.T.; Olsen, C.R.

1991-09-01

On April 1, 1986, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge National Laboratory (ORNL) (EPA 1986). As specified in Part 3: Special Conditions (Item H) of the permit, a plan for biological monitoring of the Clinch River, White Oak Creek (WOC), Northwest Tributary (NWT) of WOC, Melton Branch (MB), Fifth Creek, and First Creek shall be submitted for approval to the US Environmental Protection Agency (EPA) and the Tennessee Department of Health and Environment (TDHE) within 90 days of the effective date of the permit. The plan, which is referred to in Part 3 (H) of the permit as the Biological Monitoring Plan and Abatement Program (BMPAP), describes characterization monitoring studies to be conducted for the duration of the permit (5 years). In order to be consistent with the terminology used for the Biological Monitoring and Abatement Programs for the Oak Ridge Y-12 Plan and the Oak Ridge K-25 Plant, BMPAP will subsequently be referred to as the Biological Monitoring and Abatement Program (BMAP). The proposed BMAP outlined in this document is based on preliminary discussions held on December 9, 1985, between staff of Martin Marietta Energy Systems, Inc. (ORNL and Central Management), the US Department of Energy (DOE), EPA, and TDHE. 232 refs., 11 figs., 7 tabs

Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

Energy Technology Data Exchange (ETDEWEB)

Loar, J.M.; Adams, S.M.; Allison, L.J.; Blaylock, B.G.; Boston, H.L.; Huston, M.A.; Kimmel, B.L.; Smith, J.G.; Southworth, G.R.; Stewart, A.J.; Walton, B.T.; Kitchings, J.T.; Olsen, C.R.

1991-09-01

On April 1, 1986, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge National Laboratory (ORNL) (EPA 1986). As specified in Part 3: Special Conditions (Item H) of the permit, a plan for biological monitoring of the Clinch River, White Oak Creek (WOC), Northwest Tributary (NWT) of WOC, Melton Branch (MB), Fifth Creek, and First Creek shall be submitted for approval to the US Environmental Protection Agency (EPA) and the Tennessee Department of Health and Environment (TDHE) within 90 days of the effective date of the permit. The plan, which is referred to in Part 3 (H) of the permit as the Biological Monitoring Plan and Abatement Program (BMPAP), describes characterization monitoring studies to be conducted for the duration of the permit (5 years). In order to be consistent with the terminology used for the Biological Monitoring and Abatement Programs for the Oak Ridge Y-12 Plan and the Oak Ridge K-25 Plant, BMPAP will subsequently be referred to as the Biological Monitoring and Abatement Program (BMAP). The proposed BMAP outlined in this document is based on preliminary discussions held on December 9, 1985, between staff of Martin Marietta Energy Systems, Inc. (ORNL and Central Management), the US Department of Energy (DOE), EPA, and TDHE. 232 refs., 11 figs., 7 tabs.

Some natural factors that govern the management of oaks

Science.gov (United States)

Sidney Weitzman; G. R., Jr. Trimble

1957-01-01

The oaks are the most important species group in the Appalachian hardwood forests. In West Virginia, oaks provide more than half of the lumber produced in the State. In addition, they provide a large portion of the mine timbers and specialty products.

Consequences of Phytophthora ramorum infection in coast live oaks

Science.gov (United States)

Brice McPherson; David L. Wood; Sylvia R. Mori; Pavel Svihra; Richard B. Standiford; N. Maggi. Kelly

2008-01-01

Sudden oak death, caused by Phytophthora ramorum, has infected and killed large numbers of oaks (Quercus spp.) and tanoaks (Lithocarpus densiflorus) in California since the mid 1990s. Since March 2000 we have been investigating the interactions between patterns of disease progression and...

FY 1995 Remedial Investigation Work Plan for Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Watkins, D.R.; Herbes, S.E.

1994-12-01

The purpose of this project is to provide key information needed by decision makers to expedite the process of environmental restoration and to provide the data base required by the Remedial Investigation/Feasibility Study (RI/FS) for Waste Area Grouping (WAG) 2 at Oak Ridge National Laboratory (ORNL). WAG 2 is the major drainage system downgradient of other WAGs that contain significant sources of contamination at ORNL. Field activities to support the remedial investigation for the RI portion include characterization of the nature and extent of contamination in WAG 2 [consisting of White Oak Creek (WOC) and associated tributaries and floodplain, White Oak Lake (WOL), and White Oak Creek Embayment (WOCE)], specifically to support risk-based remediation decisions. The project consists of three phases: Phase 1, initial scoping characterization to determine the need for early action; Phase 2, interim activities during remediation of upslope WAGs to evaluate potential changes in the contamination status of WAG 2 that would necessitate revaluation of the need for early action; and Phase 3, completion of the RI process following remediation of upslope WAGs. Overall RI objectives, consistent with ORNL Environmental Restoration (ER) Program strategic objectives to reduce risks and comply with environmental regulations, are discussed in the WAG 2 Remedial Investigation Plan

Wild Boar Impact to the Natural Regeneration of Oak and Acorn Importance in its Diet

Directory of Open Access Journals (Sweden)

Jaroslav Zeman

2016-01-01

Full Text Available In this study, the impact of wild boar on the natural regeneration of oak and importance of acorns in the wild boar diet were surveyed. The data were collected near Moravian Krumlov (Czech Republic in three types of oak stands differing in the canopy density: fully-stocked stand (1, open-canopy stand (2 and the forest stand in a conversion to the coppice forest (3. Within each stand 150 m long lines were set out. Seed traps to collect acorn harvest and control plots were installed on these lines. The plots were inspected at weekly intervals. After the end of acorn fall the average amount of fallen acorns was evaluated. The quantity of metabolizable energy in acorns was assessed and daily survival dose of energy for average weight of wild boar was counted. In spring 2014 the number of seedlings was counted at the same plots. Production of acorns per hectare and basic energy needs for one individual wild boar per day were evaluated for each chosen stand type. The found seedling density amounted to 29,600, 32,000 and 14,000 ind./ha in the first, second and third stand under study, respectively. Wild boar is a major consumer of acorns. In the studied area the production of acorns sufficiently supplied the local wild boar population during winter. Necessary amount of acorns remained for the natural regeneration.

UAV – a useful tool for monitoring woodlands

Directory of Open Access Journals (Sweden)

Zmarz Anna

2014-06-01

Full Text Available Unmanned aerial systems are in many countries one of the most dynamically developing branches of technology. They have also been recognized and are being utilized by scientists who find remote sensing indispensable in their work. Today, it is increasingly common to find research teams utilizing so-called drones in field research. Unmanned systems are becoming ever more important for environment monitoring by, on the one hand, providing data from inaccessible or remote areas, and, on the other hand, reducing the human costs required by traditional large field teams while also increasing the efficiency of the work. This paper presents the possibility of utilizing UAVs for image data collection in woodland areas.

Relationships between biotic and abiotic factors and regeneration of chestnut oak, white oak, and northern red oak

Science.gov (United States)

Songlin Fei; Kim C. Steiner; James C. Finley; Marc E. McDill

2003-01-01

A series of substantial field surveys of 38 mixed-oak stands in central Pennsylvania were carried out during 1996-2000. All the stands were surveyed 1 year prior to harvest, and 16 stands have been surveyed 1 year after harvest. Three abiotic factors at stand scale, four abiotic factors at plot scale, and two biotic factors and one abiotic factor at subplot scale was...

Oak conservation and restoration on private forestlands: negotiating a social-ecological landscape.

Science.gov (United States)

Knoot, Tricia G; Schulte, Lisa A; Rickenbach, Mark

2010-01-01

In the midwestern United States, oak (Quercus spp.) forests are considered critical habitat for conserving biodiversity and are a declining resource. Ecological conditions, such as deer herbivory and competition from more mesic broad-leaved deciduous species, have been linked to poor oak regeneration. In the Midwest, where up to 90% of forestland is privately owned, a greater understanding of social dimensions of oak regeneration success is especially critical to designing effective restoration strategies. We sought to determine factors that serve as direct and indirect constraints to oak restoration and identify policy mechanisms that could improve the likelihood for restoration success. We conducted in-depth qualitative interviews with 32 natural resource professionals working in the Midwest Driftless Area. We found that most professionals anticipate that oak will remain only a component of the future forest. Furthermore, they identified the general unwillingness of landowners to adopt oak restoration practices as a primary driving force of regional forest change. The professionals pointed to interdependent ecological and social factors, occurring at various scales (e.g., economic cost of management, deer herbivory, and exurban residential development) as influencing landowner oak restoration decisions. Professionals emphasized the importance of government cost-share programs and long-term personal relationships to securing landowner acceptance of oak restoration practices. However, given finite societal resources, ecologically- and socially-targeted approaches were viewed as potential ways to optimize regional success.

Rainfall, soil moisture, and runoff dynamics in New Mexico pinon-juniper woodland watersheds

Science.gov (United States)

Carlos Ochoa; Alexander Fernald; Vincent Tidwell

2008-01-01

Clearing trees in pinon-juniper woodlands may increase grass cover and infiltration, leading to reduced surface runoff and erosion. This study was conducted to evaluate pinon-juniper hydrology conditions during baseline data collection in a paired watershed study. We instrumented six 1.0 to 1.3 ha experimental watersheds near Santa Fe, NM to collect rainfall, soil...

Co-adapting societal and ecological interactions following large disturbances in urban park woodlands

Science.gov (United States)

Margaret Carreiro; Wayne Zipperer

2011-01-01

The responses of urban park woodlands to large disturbances provide the opportunity to identify and examine linkages in social-ecological systems in urban landscapes.We propose that the Panarchy model consisting of hierarchically nested adaptive cycles provides a useful framework to evaluate those linkages.We use two case studies as examples – Cherokee Park in...

Soil respiration and organic carbon dynamics with grassland conversions to woodlands in temperate china.

Directory of Open Access Journals (Sweden)

Wei Wang

Full Text Available Soils are the largest terrestrial carbon store and soil respiration is the second-largest flux in ecosystem carbon cycling. Across China's temperate region, climatic changes and human activities have frequently caused the transformation of grasslands to woodlands. However, the effect of this transition on soil respiration and soil organic carbon (SOC dynamics remains uncertain in this area. In this study, we measured in situ soil respiration and SOC storage over a two-year period (Jan. 2007-Dec. 2008 from five characteristic vegetation types in a forest-steppe ecotone of temperate China, including grassland (GR, shrubland (SH, as well as in evergreen coniferous (EC, deciduous coniferous (DC and deciduous broadleaved forest (DB, to evaluate the changes of soil respiration and SOC storage with grassland conversions to diverse types of woodlands. Annual soil respiration increased by 3%, 6%, 14%, and 22% after the conversion from GR to EC, SH, DC, and DB, respectively. The variation in soil respiration among different vegetation types could be well explained by SOC and soil total nitrogen content. Despite higher soil respiration in woodlands, SOC storage and residence time increased in the upper 20 cm of soil. Our results suggest that the differences in soil environmental conditions, especially soil substrate availability, influenced the level of annual soil respiration produced by different vegetation types. Moreover, shifts from grassland to woody plant dominance resulted in increased SOC storage. Given the widespread increase in woody plant abundance caused by climate change and large-scale afforestation programs, the soils are expected to accumulate and store increased amounts of organic carbon in temperate areas of China.

Long-term changes in organic matter of woodland soils cleared for arable cropping in Zimbabwe

NARCIS (Netherlands)

Zingore, S.; Manyame, C.; Nyamugafata, P.; Giller, K.E.

2005-01-01

Subsistence farmers in Africa depend largely on the soil organic matter to sustain crop productivity. Long-term changes in soil organic carbon and nitrogen were measured after woodland clearance for smallholder subsistence farming or for commercial farming. The contents of organic carbon and

Oak Ridge Dose Reconstruction Project Summary Report; Reports of the Oak Ridge Dose Reconstruction, Vol. 7

International Nuclear Information System (INIS)

Widner, Thomas E.; email = twidner@jajoneses.com

1999-01-01

In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel of individuals appointed by Tennessee's Commissioner of Health. The panel requested that the principal investigator for the project prepare the following report, ''Oak Ridge Dose Reconstruction Project Summary Report,'' to serve the following purposes: (1) summarize in a single, less technical report, the methods and results of the various investigations that comprised the Phase II of the dose reconstruction; (2) describe the systematic searching of classified and unclassified historical records that was a vital component of the project; and (3) summarize the less detailed, screening-level assessments that were performed to evaluate the potential health significance of a number of materials, such a uranium, whose priority did not require a complete dose reconstruction effort. This report describes each major step of the dose reconstruction study: (1) the review of thousands of historical records to obtain information relating to past operations at each facility; (2) estimation of the quantity and timing of releases of radioiodines from X-10, of mercury from Y-12, of PCB's from all facilities, and of cesium-137 and other radionuclides from White Oak Creek; (3) evaluation of the routes taken by these contaminants through the environment to nearby populations; and (4) estimation of doses and health risks to exposed groups. Calculations found the highest excess cancer risks for a female born in 1952 who drank goat milk; the highest non-cancer health risk was for children in a farm family exposed to PCBs in and near East Fork Poplar Creek. More detailed

Effects of a Major Tree Invader on Urban Woodland Arthropods

Science.gov (United States)

2015-01-01

Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity. PMID:26359665

Effects of a Major Tree Invader on Urban Woodland Arthropods.

Directory of Open Access Journals (Sweden)

Sascha Buchholz

Full Text Available Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia, which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera; 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity.

Effects of a Major Tree Invader on Urban Woodland Arthropods.

Science.gov (United States)

Buchholz, Sascha; Tietze, Hedwig; Kowarik, Ingo; Schirmel, Jens

2015-01-01

Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity.

Assemblages of saproxylic beetles on large downed trunks of oak.

Science.gov (United States)

Milberg, Per; Bergman, Karl-Olof; Sancak, Kerem; Jansson, Nicklas

2016-03-01

Old living oaks (Quercus robur) are known as a very species-rich habitat for saproxylic beetles, but it is less clear to what extent such veteran trees differ from an even rarer feature: downed trunks of large oaks. In this study, we set out to sample this habitat, using window traps, with two aims: (1) to describe the variation of assemblages among downed trunks of different type and (2) to compare beetles on downed oaks with data from veteran standing trees. The results showed that trunk volume and sun exposure better explained assemblages as well as species numbers on downed trunks than did decay stage. Furthermore, species classified as facultative saproxylic species showed weak or no differentiation among downed trunks. Species with different feeding habits showed no apparent differentiation among downed trunks. Furthermore, species composition on dead, downed oak trunks differed sharply from that of living, veteran oaks. Wood or bark feeders were more common on veterans than downed trunks, but there was no difference for those species feeding on fungi or those feeding on insects and their remains. In conclusion, for a successful conservation of the saproxylic beetle fauna it is important to keep downed oak trunks, and particularly large ones, in forest and pastures as they constitute a saproxylic habitat that differs from that of living trees.

A dynamic compartmental food chain model of radiocaesium transfer to Apodemus sylvaticus in woodland ecosystems

International Nuclear Information System (INIS)

Toal, M.E.; Copplestone, D.; Johnson, M.S.; Jackson, D.; Jones, S.R.

2001-01-01

A study was undertaken to quantify the activity concentrations of 137Cs in Apodemus sylvaticus (the woodmouse) in two woodland sites, Lady Wood and Longrigg Wood, adjacent to British Nuclear Fuels Ltd. (BNFL) Sellafield, Cumbria, UK. A deterministic dynamic compartmental food chain model was also constructed to predict 137Cs activity concentration [Bq kg -1 dry weight (dw)] in A. sylvaticus on a seasonal basis given the activity concentrations in its diet. Within the coniferous woodland site (Lady Wood), significant differences were found between seasons (P x / 2.3 Bq kg -1 dw) being attributed to mycophagy. Fungal concentrations ranged from 2-3213 Bq kg -1 dw. The modelled activity concentrations fell between the confidence intervals of the observed data in four of the six seasonal cohorts sampled. Disparities between predicted and observed activity concentrations are attributed to uncertainties surrounding the fundamental feeding ecology of small mammals

Effects of pedunculate oak tree vitality on gypsy moth preference and performance

Directory of Open Access Journals (Sweden)

Milanović Slobodan

2014-01-01

Full Text Available Gypsy moths and powdery mildew play a significant role in oak decline processes. However, information is lacking on the effects on the gypsy moth of impaired tree vitality caused by defoliation or parasite infection. We assessed how pedunculate oak leaves collected from vigorous, declining, and infected trees influenced gypsy moth preference and performance (growth and nutritional indices. We found a negative effect of powdery mildew-infected leaves on gypsy moth performance, while declining trees had positive effects on gypsy moth performance and preference. All examined parameters of larvae fed declining oak leaves were higher than those of larvae fed vigorous oak leaves. Increased growth on declining oak leaves was caused by both higher consumption and more efficient food utilization. The results of this research could help us to better understand multitrophic interactions in complex communities such as oak forests. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

Reduction of tree cover in West African woodlands and promotion in semi-arid farmlands

Science.gov (United States)

Brandt, Martin; Rasmussen, Kjeld; Hiernaux, Pierre; Herrmann, Stefanie; Tucker, Compton J.; Tong, Xiaoye; Tian, Feng; Mertz, Ole; Kergoat, Laurent; Mbow, Cheikh; David, John L.; Melocik, Katherine A.; Dendoncker, Morgane; Vincke, Caroline; Fensholt, Rasmus

2018-05-01

Woody vegetation in farmland acts as a carbon sink and provides ecosystem services for local people, but no macroscale assessments of the impact of management and climate on woody cover exist for drylands. Here we make use of very high spatial resolution satellite imagery to derive wall-to-wall woody cover patterns in tropical West African drylands. Our study reveals that mean woody cover in farmlands along all semi-arid and sub-humid rainfall zones is 16%, on average only 6% lower than in savannahs. In semi-arid Sahel, farmland management promotes woody cover around villages (11%), while neighbouring savannahs had on average less woody cover. However, farmlands in sub-humid zones have a greatly reduced woody cover (21%) as compared with savannahs (33%). In the region as a whole, rainfall, terrain and soil are the most important (80%) determinants of woody cover, while management factors play a smaller (20%) role. We conclude that agricultural expansion causes a considerable reduction of trees in woodlands, but observations in Sahel indicate that villagers safeguard trees on nearby farmlands which contradicts simplistic ideas of a high negative correlation between population density and woody cover.

Chemical ecology of sudden oak death/ambrosia beetle interactions

Science.gov (United States)

Frances S. Ockels; Pierluigi Bonello; Brice McPherson; David L. Wood

2006-01-01

Coast live oaks, Quercus agrifolia, infected with Phytophthora ramorum in California produce a characteristic sequence of symptoms and signs. Ambrosia beetles consistently tunnel into the bark of bleeding cankers in naturally infected trees. In field monitoring conducted since 2000, every bleeding coast live oak that subsequently...

Microsatellite Primer Development for Post Oak, Quercus stellata (Fagaceae

Directory of Open Access Journals (Sweden)

Warren B. Chatwin

2014-10-01

Full Text Available Premise of the study: The American Cross Timbers forest ecosystem runs from southeastern Kansas to Central Texas and is primarily composed of post oak (Quercus stellata. This old-growth forest currently occupies only about 2% of its ancestral range. To facilitate genetic research on this species, we developed microsatellite primers specific to post oak from reduced genomic libraries. Methods and Results: Two Q. stellata individuals, sampled from the northern and southern range of the post oak forest, were subject to genomic reduction and 454 pyrosequencing. Bioinformatic analysis identified putative microsatellites from which 12 polymorphic primer sets were screened on three populations. The number of alleles observed ranged from five to 20 across all populations, while observed and expected heterozygosity values ranged from 0.05 to 0.833 and 0.236 to 0.893, respectively, within individual populations. Conclusions: We report the development of microsatellite markers, specific to post oak, to aid the study of genetic diversity and population structure of extant forest remnants.

Association of weather and nest-site structure with reproductive success in California spotted owls

Science.gov (United States)

Malcolm North; George Steger; Renee Denton; Gary Eberlein; Tom Munton; Ken Johnson

2000-01-01

Although the spotted owl (Strix occidentalis) has been intensively studied, factors influencing its reproduction are not well understood. We examined a 9-year demographic study of 51-86 pairs of the California spotted owl (S. o. occidentalis), weather conditions, and forest structure at nest sites in oak (Quercus sp.) woodland and...

Red maple (Acer rubrum) response to prescribed burning on the William B. Bankhead National Forest, Alabama

Science.gov (United States)

Stacy L. Clark; Callie Jo Schweitzer

2013-01-01

Prescribed burning is used as a management tool on national forests in the Southeastern United States to maintain oak (Quercus spp.) -dominated forest or woodland habitat. Few studies have examined response to burning at the stand, plot, and tree level. We documented red maple (Acer rubrum) response to dormant-season prescribed...

Genetic structure of Notholithocarpus densiflorus(Fagaceae) from the species to the local scale: A review of our knowledge for conservation and replanting

Science.gov (United States)

Richard S Dodd; Alejandro Nettel; Jessica W. Wright; Zara Afzal-Rafii

2013-01-01

Tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh (Fagaceae), is an important component of mixed-evergreen forests and woodlands in coastal California and Oregon, with incursions into the Sierra Nevada and the Klamath Ranges. Sudden Oak Death (SOD) is causing severe dieback and mortality in tanoak and could...

Melton Valley Storage Tanks Capacity Increase Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1995-04-01

The US Department of Energy (DOE) proposes to construct and maintain additional storage capacity at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, for liquid low-level radioactive waste (LLLW). New capacity would be provided by a facility partitioned into six individual tank vaults containing one 100,000 gallon LLLW storage tank each. The storage tanks would be located within the existing Melton Valley Storage Tank (MVST) facility. This action would require the extension of a potable water line approximately one mile from the High Flux Isotope Reactor (HFIR) area to the proposed site to provide the necessary potable water for the facility including fire protection. Alternatives considered include no-action, cease generation, storage at other ORR storage facilities, source treatment, pretreatment, and storage at other DOE facilities

Sudden oak death: disease trends in Marin county plots after one year

Science.gov (United States)

Brice A. McPherson; David L. Wood; Andrew J. Storer; Nina Maggi Kelly; Richard B. Standiford

2002-01-01

Sudden oak death has emerged as a major threat to the oak forests of California. In oaks and tanoak, this disease complex consists of a previously unreported fungus-like pathogen, Phytophthora ramorum, insects (bark and ambrosia beetles), and a secondary fungus, Hypoxylon thouarsianum. Species monitored in this study were coast...

Analysis of landscape patterns and their relationship with oak (Quercus Humboldtii Bonpl.) regeneration in the municipality of Popayan, Cauca

International Nuclear Information System (INIS)

Cabezas Gaviria Alexander; Ospina Montealegre Roman

2010-01-01

Landscape patterns were determined for three different areas having oak populations in the Popayan municipality (Clarete, Rejoya and Pisoje). Two Landsat images from different years and polygons with areas equal or greater than 1.5 hectares were used for land use classification. Patch Analysis software was used in order to determine quantitative variables. Structure description included: number of patches, mean patch size, mean patch index, mean patch fractal dimension and mean perimeter-area ratio. Dispersion and fragmentation were evaluated with the three indexes: Mean Nearest Neighbor Distance, Mean Proximity Index and Interspersion Juxtaposition Index. Community variables included: basal area, terrain slope, light percentage and regeneration density, and were measured in an area of 3600 m2 for each landscape. Landscape and community information were analyzed using principal component analysis (PCA). The first two components explained 91.4% of data variability; they were determined mostly by landscape variables than community factors. Correlation analysis and the Kruskal-Wallis test showed that the variable of major importance regarding oak tree regeneration were the Neighbor Distance in secondary forest patches, the Mean Proximity Index in oak tree forest patches and the Juxtaposition Index in patches of planted forests.

Site characterization plan for groundwater in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

Lee, R.R.; Curtis, A.H.; Houlberg, L.M.; Purucker, S.T.; Singer, M.L.; Tardiff, M.F.; Wolf, D.A.

1994-07-01

The Waste Area Grouping (WAG) 1 Groundwater Operable Unit (OU) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, is undergoing a site characterization to identify environmental contamination that may be present. This document, Site Characterization Report for Groundwater in Waste Area Grouping I at Oak Ridge National Laboratory, Oak Ridge, Tennessee, identifies areas of concern with respect to WAG 1 groundwater and presents the rationale, justification, and objectives for conducting this continuing site characterization. This report summarizes the operations that have taken place at each of the areas of concern in WAG 1, summarizes previous characterization studies that have been performed, presents interpretations of previously collected data and information, identifies contaminants of concern, and presents an action plan for further site investigations and early actions that will lead to identification of contaminant sources, their major groundwater pathways, and reduced off-site migration of contaminated groundwater to surface water. Site characterization Activities performed to date at WAG I have indicated that groundwater contamination, principally radiological contamination, is widespread. An extensive network of underground pipelines and utilities have contributed to the dispersal of contaminants to an unknown extent. The general absence of radiological contamination in surface water at the perimeter of WAG 1 is attributed to the presence of pipelines and underground waste storage tank sumps and dry wells distributed throughout WAG 1 which remove more than about 40 million gal of contaminated groundwater per year.

Site characterization plan for groundwater in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Lee, R.R.; Curtis, A.H.; Houlberg, L.M.; Purucker, S.T.; Singer, M.L.; Tardiff, M.F.; Wolf, D.A.

1994-07-01

The Waste Area Grouping (WAG) 1 Groundwater Operable Unit (OU) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, is undergoing a site characterization to identify environmental contamination that may be present. This document, Site Characterization Report for Groundwater in Waste Area Grouping I at Oak Ridge National Laboratory, Oak Ridge, Tennessee, identifies areas of concern with respect to WAG 1 groundwater and presents the rationale, justification, and objectives for conducting this continuing site characterization. This report summarizes the operations that have taken place at each of the areas of concern in WAG 1, summarizes previous characterization studies that have been performed, presents interpretations of previously collected data and information, identifies contaminants of concern, and presents an action plan for further site investigations and early actions that will lead to identification of contaminant sources, their major groundwater pathways, and reduced off-site migration of contaminated groundwater to surface water. Site characterization Activities performed to date at WAG I have indicated that groundwater contamination, principally radiological contamination, is widespread. An extensive network of underground pipelines and utilities have contributed to the dispersal of contaminants to an unknown extent. The general absence of radiological contamination in surface water at the perimeter of WAG 1 is attributed to the presence of pipelines and underground waste storage tank sumps and dry wells distributed throughout WAG 1 which remove more than about 40 million gal of contaminated groundwater per year

Productivity Contribution of Paleozoic Woodlands to the Formation of Shale-Hosted Massive Sulfide Deposits in the Iberian Pyrite Belt (Tharsis, Spain)

Science.gov (United States)

Fernández-Remolar, David C.; Harir, Mourad; Carrizo, Daniel; Schmitt-Kopplin, Philippe; Amils, Ricardo

2018-03-01

The geological materials produced during catastrophic and destructive events are an essential source of paleobiological knowledge. The paleobiological information recorded by such events can be rich in information on the size, diversity, and structure of paleocommunities. In this regard, the geobiological study of late Devonian organic matter sampled in Tharsis (Iberian Pyrite Belt) provided some new insights into a Paleozoic woodland community, which was recorded as massive sulfides and black shale deposits affected by a catastrophic event. Sample analysis using TOF-SIMS (Time of Flight Secondary Ion Mass Spectrometer), and complemented by GC/MS (Gas Chromatrograph/Mass Spectrometer) identified organic compounds showing a very distinct distribution in the rock. While phytochemical compounds occur homogeneously in the sample matrix that is composed of black shale, the microbial-derived organics are more abundant in the sulfide nodules. The cooccurrence of sulfur bacteria compounds and the overwhelming presence of phytochemicals provide support for the hypothesis that the formation of the massive sulfides resulted from a high rate of vegetal debris production and its oxidation through sulfate reduction under suboxic to anoxic conditions. A continuous supply of iron from hydrothermal activity coupled with microbial activity was strictly necessary to produce this massive orebody. A rough estimate of the woodland biomass was made possible by accounting for the microbial sulfur production activity recorded in the metallic sulfide. As a result, the biomass size of the late Devonian woodland community was comparable to modern woodlands like the Amazon or Congo rainforests.

Third report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

Energy Technology Data Exchange (ETDEWEB)

Loar, J.M. [ed.; Adams, S.M.; Bailey, R.D. [and others

1994-03-01

As a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1985, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC); selected tributaries of WOC, including Fifth Creek, First Creek, Melton Branch, and Northwest Tributary; and the Clinch River. The BMAP currently consists of six major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs at ORNL. These are (1) toxicity monitoring, (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota, (3) biological indicator studies, (4) instream ecological monitoring, (5) assessment of contaminants in the terrestrial environment, and (6) radioecology of WOC and White Oak Lake (WOL). The investigation of contaminant transport, distribution, and fate in the WOC embayment-Clinch River-Watts Bar Reservoir system was originally a task of the BMAP but, in 1988, was incorporated into the Resource Conservation and Recovery Act Facility Investigation for the Clinch River, a separate study to assess offsite contamination from all three Department of Energy facilities in Oak Ridge.

Third report on the Oak Ridge National Laboratory Biological Monitoring and Abatement Program for White Oak Creek Watershed and the Clinch River

International Nuclear Information System (INIS)

Loar, J.M.; Adams, S.M.; Bailey, R.D.

1994-03-01

As a condition of the National Pollutant Discharge Elimination System (NPDES) permit issued to Oak Ridge National Laboratory (ORNL) on April 1, 1985, a Biological Monitoring and Abatement Program (BMAP) was developed for White Oak Creek (WOC); selected tributaries of WOC, including Fifth Creek, First Creek, Melton Branch, and Northwest Tributary; and the Clinch River. The BMAP currently consists of six major tasks that address both radiological and nonradiological contaminants in the aquatic and terrestrial environs at ORNL. These are (1) toxicity monitoring, (2) bioaccumulation monitoring of nonradiological contaminants in aquatic biota, (3) biological indicator studies, (4) instream ecological monitoring, (5) assessment of contaminants in the terrestrial environment, and (6) radioecology of WOC and White Oak Lake (WOL). The investigation of contaminant transport, distribution, and fate in the WOC embayment-Clinch River-Watts Bar Reservoir system was originally a task of the BMAP but, in 1988, was incorporated into the Resource Conservation and Recovery Act Facility Investigation for the Clinch River, a separate study to assess offsite contamination from all three Department of Energy facilities in Oak Ridge

Movement pathways and habitat selection by woodland caribou during spring migration

Directory of Open Access Journals (Sweden)

D. Joanne Saher

2005-05-01

Full Text Available Woodland caribou (Rangifer tarandus caribou are a threatened species throughout Canada. Special management is therefore required to ensure habitat needs are met, particularly because much of their current distribution is heavily influenced by resource extraction activities. Although winter habitat is thought to be limiting and is the primary focus of conservation efforts, maintaining connectivity between summer and winter ranges has received little attention. We used global positioning system data from an interprovincial, woodland caribou herd to define migratory movements on a relatively pristine range. Non-linear models indicated that caribou movement during migration was punctuated; caribou traveled for some distance (movement phase followed by a pause (resting/foraging phase. We then developed resource selection functions (RSFs, using case-controlled logistic regression, to describe resting/foraging sites and movement sites, at the landscape scale. The RSFs indicated that caribou traveled through areas that were less rugged and closer to water than random and that resting/foraging sites were associated with older forests that have a greater component of pine, and are further from water than were random available locations. This approach to analyzing animal location data allowed us to identify two patterns of habitat selection (travel and foraging/resting for caribou during the migratory period. Resultant models are important tools for land use planning to ensure that connectivity between caribou summer and winter ranges is maintained.

Diversity and production of Ethiopian dry woodlands explained by climate- and soil- stress gradients

NARCIS (Netherlands)

Eshete, A.; Sterck, F.J.; Bongers, F.

2011-01-01

Dry woodlands cover about 14% of the total African land surface and represent about 25% of the natural vegetation. They are characterized by a seasonal climate, with a dry season of 4–7 months. Large parts of these ecosystems are degrading due to grazing, fire or exploitation by people. We studied

Geophysical survey work plan for White Wing Scrap Yard (Waste Area Grouping 11) at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1994-02-01

The White Wing Scrap Yard, located on the U.S. Department of Energy's Oak Ridge Reservation, served as an aboveground storage and disposal area for contaminated debris and scrap from the Oak Ridge K-25 Site, the Oak Ridge Y-12 Plant, and the Oak Ridge National laboratory. The site is believed to have been active from the early 1950s until the mid-1960s. A variety of materials were disposed of at the site, including contaminated steel tanks and vehicles. As an interim corrective action, a surface debris removal effort was initiated in November 1993 to reduce the potential threat to human health and the environment from the radionuclide-contaminated debris. Following this removal effort, a geophysical survey will be conducted across the site to locate and determine the lateral extent of buried nonindigenous materials. This survey will provide the data necessary to prepare a map showing areas of conductivity and magnetic intensity that vary from measured background values. These anomalies represent potential buried materials and therefore can be targeted for further evaluation. This work plan outlines the activities necessary to conduct the geophysical survey

Bear Creek Valley Floodplain Hot Spot Removal Action Project Plan, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1998-01-01

The Bear Creek Valley Floodplain Hot Spot Removal Action Project Plan, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee (Y/ER-301) was prepared (1) to safely, cost-effectively, and efficiently evaluate the environmental impact of solid material in the two debris areas in the context of industrial land uses (as defined in the Bear Creek Valley Feasibility Study) to support the Engineering Evaluation/Cost Assessment and (2) to evaluate, define, and implement the actions to mitigate these impacts. This work was performed under Work Breakdown Structure 1.x.01.20.01.08

Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry.

Science.gov (United States)

Mämmelä, P; Savolainen, H; Lindroos, L; Kangas, J; Vartiainen, T

2000-09-01

Extractable tannins were analysed by liquid chromatography-electrospray ionisation mass spectrometry in two oak species, North American white oak (Quercus alba) and European red oak (Quercus robur). They mainly included various glucose gallic and ellagic acid esters. The structures were partially determined, and they included grandinin/roburin E, castalagin/vescalagin, gallic acid, valoneic acid bilactone, monogalloyl glucose, digalloyl glucose, trigalloyl glucose, ellagic acid rhamnose, quercitrin and ellagic acid.

Leaf elemental analysis in mycorrhizal post oak seedlings

Energy Technology Data Exchange (ETDEWEB)

Boling, B.C. [Department of Biology, University of North Texas, P.O. Box 305220, Denton, TX 76203-5220 (United States); Naab, F.U. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States)]. E-mail: fun001@unt.edu; Smith, D. [Department of Biology, University of North Texas, P.O. Box 305220, Denton, TX 76203-5220 (United States); Duggan, J.L. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); McDaniel, F.D. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States)

2006-09-15

Growth and element assimilation was investigated in the leaves of post oak seedlings exposed to four different treatment combinations of fertilization and ectomycorrhizal inoculation. Element concentration was analyzed via particle-induced X-ray emission spectrometry (PIXE). PIXE detected 10 of the 13 essential macro and micronutrients: P, S, Mg, Ca, K, Cu, Zn, Mn, Fe and Cl. Mean growth and dry weight was significantly different across the treatment groups as well as the mean concentration of Mg, Al, S, K, Ca, Fe, Cu and Zn. The data suggest that fertilization rather than mycorrhizal inoculation had a stronger influence on nutrient uptake. This study is the first to analyze element concentration in post oak and to investigate the potential benefits of mycorrhizal symbiosis in post oak seedlings in terms of nutrient uptake.

Sustaining oak forests in eastern North America: regeneration and recruitment, the pillars of sustainability

Science.gov (United States)

Daniel C. Dey

2014-01-01

Oak cover types comprise half of the forestlands in the eastern United States. There is a great desire to sustain these highly valued forests. Unfortunately, reports of the successional replacement of oak are all too common, as they are throughout the world. Sustaining the oak resource requires the ability to both regenerate and recruit oak into the overstory as...

Woodland pond salamander abundance in relation to forest management and environmental conditions in northern Wisconsin

Science.gov (United States)

Deahn M. Donner; Christine A. Ribic; Albert J. Beck; Dale Higgins; Dan Eklund; Susan. Reinecke

2015-01-01

Woodland ponds are important landscape features that help sustain populations of amphibians that require this aquatic habitat for successful reproduction. Species abundance patterns often reflect site-specific differences in hydrology, physical characteristics, and surrounding vegetation. Large-scale processes such as changing land cover and environmental conditions...

Vegetation studies on Vandenberg Air Force Base, California

Science.gov (United States)

Schmalzer, Paul A.; Hickson, Diana E.; Hinkle, C. Ross

1988-01-01

Vandenburg Air Force Base, located in coastal central California with an area of 98,400 ac, contains resources of considerable biological significance. Available information on the vegetation and flora of Vandenburg is summarized and new data collected in this project are presented. A bibliography of 621 references dealing with vegetation and related topics related to Vanderburg was compiled from computer and manual literature searches and a review of past studies of the base. A preliminary floristic list of 642 taxa representing 311 genera and 80 families was compiled from past studies and plants identified in the vegetation sampling conducted in this project. Fifty-two special interest plant species are known to occur or were suggested to occur. Vegetation was sampled using permanent plots and transects in all major plant communities including chaparral, Bishop pine forest, tanbark oak forest, annual grassland, oak woodland, coastal sage scrub, purple sage scrub, coastal dune scrub, coastal dunes, box elder riparian woodland, will riparian woodland, freshwater marsh, salt marsh, and seasonal wetlands. Comparison of the new vegetation data to the compostie San Diego State University data does not indicate major changes in most communities since the original study. Recommendations are made for additional studies needed to maintain and extend the environmental data base and for management actions to improve resource protection.

Tenth workshop on seedling physiology and growth problems in oak plantings

Science.gov (United States)

Brian Roy Lockhart; Emile S. Gardiner; Daniel C. Dey

2008-01-01

Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 15 abstracts.

Sporulation capacity of Phytophthora ramorum on northern red oak and chestnut oak

Science.gov (United States)

Branches from six 2 to 3-year old northern red and chestnut oak seedlings were dip-inoculated with ca. 5,000 sporangia per milliliter of Phytophthora ramorum isolate Pr-6 and incubated at 100 percent relative humidity in dew chambers for 6 days. Three plants were then used to assess sporangia produ...

Surface radiological investigation of Trench 5 in Waste Area Grouping 7 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Goff, D.D.

1991-08-01

A surface radiological investigation of areas encompassing Trench 5 on the Oak Ridge Reservation (ORR) was conducted from May 1990 through November 1990. This survey was led by the author, assisted by various members of the Measurement Applications and Development (MAD) group of the Health and Safety Research Division (HASRD) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The purpose of the investigation was to determine the presence, nature, and extent of surface radiological contamination at Trench 5, the Homogeneous Reactor Experiment fuel wells, and surrounding areas. Based on the data obtained in the field, interim corrective measures were recommended to limit human exposure to radioactivity and to minimize insult to the environment. It should be stressed that this project was not intended to be a complete site characterization but rather to be a preliminary investigation into the potential contamination problem that might exist as a result of past operations at Trench 5

Evaluation of fire severity via analysis of photosynthetic pigments: Oak, eucalyptus and cork oak leaves in a Mediterranean forest.

Science.gov (United States)

Soler, M; Úbeda, X

2018-01-15

Few studies to date have examined the effect of the high temperatures attained during wildfire events on the pigments present in forest foliage. Here, we seek to analyse the main photosynthetic pigments in the leaves of the oak, cork oak and eucalyptus following a wildfire. We also subject leaves of these last two species to a range of contact temperatures (100-500 °C) in the laboratory using a muffle furnace. The samples were left in the muffle for two hours at 100, 150, 200, 250, 300, 350, 400 and 500 °C, in line with other soil study models (Úbeda et al., 2009; Düdaite et al., 2013). At temperatures above 250 °C, chromatography fails to detect any pigments. A minimal increase in temperature degrades chlorophyll, the process being more rapid in eucalyptus than in cork oak, while it increases pheophytin concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.