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Sample records for density oak woodlands

  1. Cork oak woodlands patchiness

    DEFF Research Database (Denmark)

    Costa, Augusta; Madeira, Manuel; Plieninger, Tobias

    2014-01-01

    The cork oak (Quercus suber L.) woodlands of the agroforestry landscapes of Southwestern Iberia are undergoing drastic change due to severe natural and anthropogenic disturbances. These may eventually result in woodland loss or deforestation, the final step of an ongoing process of woodland...... degradation. Monitoring changes in the spatial patterns of woodlands - especially fractional canopy cover of woodlands and/or their patchiness in the landscape mosaic - potentially enables forecasting of loss and responding to it at an early stage. We examine the degradation process in two cork oak woodlands...

  2. Cork oak woodlands patchiness

    DEFF Research Database (Denmark)

    Costa, Augusta; Madeira, Manuel; Plieninger, Tobias

    2014-01-01

    The cork oak (Quercus suber L.) woodlands of the agroforestry landscapes of Southwestern Iberia are undergoing drastic change due to severe natural and anthropogenic disturbances. These may eventually result in woodland loss or deforestation, the final step of an ongoing process of woodland degra...

  3. Management of California Oak Woodlands: Uncertainties and Modeling

    Science.gov (United States)

    Jay E. Noel; Richard P. Thompson

    1995-01-01

    A mathematical policy model of oak woodlands is presented. The model illustrates the policy uncertainties that exist in the management of oak woodlands. These uncertainties include: (1) selection of a policy criterion function, (2) woodland dynamics, (3) initial and final state of the woodland stock. The paper provides a review of each of the uncertainty issues. The...

  4. The economic drivers behind residential conversion in the oak woodlands

    Science.gov (United States)

    William Stewart; James Spero; Shawn Saving

    2008-01-01

    Acre for acre, oak woodlands provide habitats for a greater range of wildlife species than grasslands and irrigated agricultural lands. Oak woodlands also are highly valued as open space around residential development. The rich habitat diversity and the physical attractiveness drives residential interest in living in or adjacent to oak woodlands as well as preservation...

  5. The oak woodland bird conservation plan: a strategy for protecting and managing oak woodland habitats and associated birds in California

    Science.gov (United States)

    Steve Zack; Mary K. Chase; Geoffrey R. Geupel

    2002-01-01

    Over 330 species of birds, mammals, reptiles, and amphibians depend on oak woodlands in California at some stage in their life cycle. California oak woodlands may rank among the top three habitat types in North America for bird richness. Oak woodlands are able to sustain such abundant wildlife primarily because they produce acorns, a high quality and frequently copious...

  6. Oak woodland conservation management planning in southern CA - lessons learned

    Science.gov (United States)

    Rosi Dagit

    2015-01-01

    The California Oak Woodlands Conservation Act (AB 242 2001) established requirements for the preservation and protection of oak woodlands and trees, and allocated funding managed by the Wildlife Conservation Board. In order to qualify to use these funds, counties and cities need to adopt an oak conservation management plan. Between 2008 and 2011, a team of concerned...

  7. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia

    DEFF Research Database (Denmark)

    Costa, A.; Madeira, M.; Lima Santos, J.

    2014-01-01

    Mediterranean evergreen oak woodlands (composed of Quercus suber L. and Quercus rotundifolia Lam.) are becoming increasingly fragmented in the human-modified landscapes of Southwestern Portugal and Spain. Previous studies have largely neglected to assess the spatial changes of oak woodlands in re...

  8. Silvicultural considerations for managing fire-dependent oak woodland ecosystems

    Science.gov (United States)

    John M. Kabrick; Daniel C. Dey; Carter O. Kinkead; Benjamin O. Knapp; Michael Leahy; Matthew G. Olson; Michael C. Stambaugh; Aaron P. Stevenson

    2014-01-01

    Oak woodlands are characterized by open understories and dense ground flora composed of forbs, grasses, and sedges. They once were common in the western Central Hardwood Forest region and the prairie-forest transition zone where low-intensity fires occurred frequently. In the absence of fire, many of the woodland ecosystems throughout much of this region have succeeded...

  9. Land Change in Eastern Mediterranean Wood-Pasture Landscapes: The Case of Deciduous Oak Woodlands in Lesvos (Greece)

    Science.gov (United States)

    Schaich, Harald; Kizos, Thanasis; Schneider, Stefan; Plieninger, Tobias

    2015-07-01

    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 remained stable with marginal losses in one study site and gains in the other one. Oak canopy cover increased by 8 and 9 %. Spatial hotspots of change were mountainous and peripheral phrygana areas with expanding oak stands, as well as river valleys and near urban areas with expanding olive groves and grass- and shrublands in former complex cultivation and oak stands. We conclude that the parallel processes of abandonment of crop cultivation and intensification of livestock grazing have been less detrimental to oak woodlands than supposed. To ensure long-term persistence of oak woodlands in the face of ongoing rural depopulation and land-use intensification, environmental and agricultural policies should better address their specificities as anthropogenic habitats.

  10. Macrofungi diversity in cork-oak and holm-oak Woodlands in Alentejo (Southern Portugal)

    OpenAIRE

    Santos-Silva,Celeste; Louro, Rogério

    2011-01-01

    With the purpose of contributing to a better knowledge of the Portuguese mycota, a compilation study of the macrofungal diversity of cork-oak and holm-oak woodlands (montado/dehesas) of Alentejo, Southern Portugal was made. This work is based on a series of macrofungi surveys, carried out by the authors, between 2005 and 2011, in six representative sites. Taxonomy and nomenclature follows Kirk et al. (2001) and Kirk (2004-2011). Current species distribution was consulted in: online intern...

  11. Influence of Scale on the Management of Wildlife in California Oak Woodlands

    Science.gov (United States)

    William M. Block; Michael L. Morrison

    1991-01-01

    Distributions, abundances, and patterns of resource use of amphibians, reptiles, birds, and small mammals varied spatially and temporally in California oak woodlands. Spatial variations occurred within stands, between stands of a similar type (e.g., canyon live oak [Quercus chrysolepis], blue oak [Q. douglasii], or valley oak [

  12. Fragmentation patterns of evergreen oak woodlands in Southwestern Iberia: identifying key spatial indicators.

    Science.gov (United States)

    Costa, Augusta; Madeira, Manuel; Lima Santos, José; Plieninger, Tobias; Seixas, Júlia

    2014-01-15

    Mediterranean evergreen oak woodlands (composed of Quercus suber L. and Quercus rotundifolia Lam.) are becoming increasingly fragmented in the human-modified landscapes of Southwestern Portugal and Spain. Previous studies have largely neglected to assess the spatial changes of oak woodlands in relation to their surrounding landscape matrix, and to characterize and quantify woodland boundaries and edges. The present study aims to fill this gap by analyzing fragmentation patterns of oak woodlands over a 50-year period (1958-2007) in three landscapes. Using archived aerial imagery from 1958, 1995 and 2007, for two consecutive periods (1958-1995 and 1995-2007), we calculated a set of landscape metrics to compare woodland fragmentation over time. Our results indicated a continuous woodland fragmentation characterized by their edge dynamics. From 1958 to 2007, the replacement of open farmland by shrubland and by new afforestation areas in the oak woodland landscape surrounding matrix, led to the highest values for edge contrast length trends of 5.0 and 12.3, respectively. Linear discriminant analysis was performed to delineate fragmented woodland structures and identify metric variables that characterize woodland spatial configuration. The edge contrast length with open farmland showed a strong correlation with F1 (correlations ranging between 0.55 and 0.98) and may be used as a proxy for oak woodland mixedness in landscape matrix. The edge dynamics of oak woodlands may result in different patterns of oak recruitment and therefore, its study may be helpful in highlighting future baselines for the sustainable management of oak woodlands.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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...

  15. Development of secondary woodland in oak wood pastures reduces the richness of rare epiphytic lichens.

    Science.gov (United States)

    Paltto, Heidi; Nordberg, Anna; Nordén, Björn; Snäll, Tord

    2011-01-01

    Wooded pastures with ancient trees were formerly abundant throughout Europe, but during the last century, grazing has largely been abandoned often resulting in dense forests. Ancient trees constitute habitat for many declining and threatened species, but the effects of secondary woodland on the biodiversity associated with these trees are largely unknown. We tested for difference in species richness, occurrence, and abundance of a set of nationally and regionally red-listed epiphytic lichens between ancient oaks located in secondary woodland and ancient oaks located in open conditions. We refined the test of the effect of secondary woodland by also including other explanatory variables. Species occurrence and abundance were modelled jointly using overdispersed zero-inflated Poisson models. The richness of the red-listed lichens on ancient oaks in secondary woodland was half of that compared with oaks growing in open conditions. The species-level analyses revealed that this was mainly the result of lower occupancy of two of the study species. The tree-level abundance of one species was also lower in secondary woodland. Potential explanations for this pattern are that the study lichens are adapted to desiccating conditions enhancing their population persistence by low competition or that open, windy conditions enhance their colonisation rate. This means that the development of secondary woodland is a threat to red-listed epiphytic lichens. We therefore suggest that woody vegetation is cleared and grazing resumed in abandoned oak pastures. Importantly, this will also benefit the vitality of the oaks.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  18. 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.

  19. Life-cycle assessment of typical Portuguese cork oak woodlands.

    Science.gov (United States)

    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.

  20. The ancient blue oak woodlands of California: longevity and hydroclimatic history

    Science.gov (United States)

    Stahle, D.W.; Griffin, R.D.; Meko, D.M.; Therrell, M.D.; Edmondson, J.R.; Cleaveland, M.K.; Burnette, D.J.; Abatzoglou, J.T.; Redmond, K.T.; Dettinger, M.D.; Cayan, D.R.

    2013-01-01

    Ancient blue oak trees are still widespread across the foothills of the Coast Ranges, Cascades, and Sierra Nevada in California. The most extensive tracts of intact old-growth blue oak woodland appear to survive on rugged and remote terrain in the south Coast Ranges and on the foothills west and southwest of Mt. Lassen. In our sampling of old-growth stands, most blue oak appear to have recruited to the canopy in the mid- to late-19th century. The oldest living blue oak tree sampled was over 459-years old and several dead blue oak logs had over 500 annual rings. Precipitation sensitive tree-ring chronologies up to 700-years long have been developed from old blue oak trees and logs. Annual ring-width chronologies of blue oak are strongly correlated with cool season precipitation totals, streamflow in the major rivers of California, and the estuarine water quality of San Francisco Bay. A new network of 36 blue oak chronologies records spatial anomalies in growth that arise from latitudinal changes in the mean storm track and location of landfalling atmospheric rivers. These long, climate-sensitive blue oak chronologies have been used to reconstruct hydroclimatic history in California and will help to better understand and manage water resources. The environmental history embedded in blue oak growth chronologies may help justify efforts to conserve these authentic old-growth native woodlands.

  1. 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.

  2. 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

  3. Design considerations for examining trends in avian abundance using point counts: examples from oak woodlands

    Science.gov (United States)

    Kathryn L. Purcell; Sylvia R. Mori; Mary K. Chase

    2005-01-01

    We used data from two oak-woodland sites in California to develop guidelines for the design of bird monitoring programs using point counts. We used power analysis to determine sample size adequacy when varying the number of visits, count stations, and years for examining trends in abundance. We assumed an overdispersed Poisson distribution for count data, with...

  4. Drivers of Productivity Trends in Cork Oak Woodlands over the Last 15 Years

    Directory of Open Access Journals (Sweden)

    Maria João Santos

    2016-06-01

    Full Text Available Higher biodiversity leads to more productive ecosystems which, in turn, supports more biodiversity. Ongoing global changes affect ecosystem productivity and, therefore, are expected to affect productivity-biodiversity relationships. However, the magnitude of these relationships may be affected by baseline biodiversity and its lifeforms. Cork oak (Quercus suber woodlands are a highly biodiverse Mediterranean ecosystem managed for cork extraction; as a result of this management cork oak woodlands may have both tree and shrub canopies, just tree and just shrub canopies, and just grasslands. Trees, shrubs, and grasses may respond differently to climatic variables and their combination may, therefore, affect measurements of productivity and the resulting productivity-biodiversity relationships. Here, we asked whether the relationship between productivity and climate is affected by the responses of trees, shrubs, and grasses in cork oak woodlands in Southern Portugal. To answer this question, we linked a 15-year time series of Enhanced Vegetation Index (EVI derived from Landsat satellites to micrometeorological data to assess the relationship between trends in EVI and climate. Between 2000 and 2013 we observed an overall decrease in EVI. However, EVI increased over cork oaks and decreased over shrublands. EVI trends were strongly positively related to changes in relative humidity and negatively related to temperature. The intra-annual EVI cycle of grasslands and sparse cork oak woodland without understorey (savannah-like ecosystem had higher variation than the other land-cover types. These results suggest that oaks and shrubs have different responses to changes in water availability, which can be either related to oak physiology, to oaks being either more resilient or having lagged responses to changes in climate, or to the fact that shrublands start senesce earlier than oaks. Our results also suggest that in the future EVI could improve because the

  5. Litter dominates surface fluxes of carbonyl sulfide in a Californian oak woodland

    OpenAIRE

    Sun, Wu; Maseyk, Kadmiel; Lett, Céline; Seibt, Ulli

    2016-01-01

    Carbonyl sulfide (COS) is a promising tracer for partitioning terrestrial photosynthesis and respiration from net carbon fluxes, based on its daytime co-uptake alongside CO2 through leaf stomata. Because ecosystem COS fluxes are the sum of plant and soil fluxes, using COS as a photosynthesis tracer requires accurate knowledge of soil COS fluxes. At an oak woodland in Southern California, we monitored below-canopy surface (soil + litter) COS and CO2 fluxes for 40 days using chambers and laser ...

  6. Performance of Burn-Severity Metrics and Classification in Oak Woodlands and Grasslands

    Directory of Open Access Journals (Sweden)

    Michael C. Stambaugh

    2015-08-01

    Full Text Available Burn severity metrics and classification have yet to be tested for many eastern U.S. deciduous vegetation types, but, if suitable, would be valuable for documenting and monitoring landscape-scale restoration projects that employ prescribed fire treatments. Here we present a performance analysis of the Composite Burn Index (CBI and its relationship to spectral data (differenced Normalized Burn Ratio (dNBR and its relative form (RdNBR across an oak woodland - grassland landscape in southwestern Oklahoma, USA. Correlation and regression analyses were used to compare CBI strata, assess models describing burn severity, and determine thresholds for burn severity classes. Confusion matrices were used to assess burn severity classification accuracy. Our findings suggest that dNBR and RdNBR, thresholded using total CBI, can produce an accurate burn severity map in oak woodlands, particularly from an initial assessment period. Lower accuracies occurred for burn severity classifications of grasslands and raises questions related to definitions and detection of burn severity for grasslands, particularly in transition to more densely treed structures such as savannas and woodlands.

  7. Responses of a Federally Endangered Songbird to Understory Thinning in Oak-Juniper Woodlands

    Science.gov (United States)

    Long, Ashley M.; Marshall, Mike E.; Morrison, Michael L.; Hays, K. Brian; Farrell, Shannon L.

    2017-04-01

    Wildlife conservation and management on military lands must be accomplished in the context of military readiness, which often includes ground-based training that is perceived to conflict with wildlife needs and environmental regulations. From 2008‒2012, we examined territory density, pairing success, and fledging success of the federally endangered golden-cheeked warbler ( Setophaga chrysoparia; hereafter warbler) in relation to removal of small-diameter trees from the understory of mature oak-juniper ( Quercus-Juniperus) woodland at the 87,890 ha Fort Hood Military Reservation in central Texas. Understory thinning created troop maneuver lanes, but left canopy vegetation intact. Warbler density, pairing success, and fledging success were similar across thinned and control sites. We found that warbler pairing and fledging success were best predicted by Ecological site (hereafter Ecosite), an indicator of hardwood tree species composition. Warbler pairing and fledging success were about 1.5 and 1.6 times higher, respectively, for territories dominated by the Low Stony Hill Ecosite than territories dominated by the Redlands Ecosite. Our results indicate that understory thinning for military training purposes did not have a negative effect on warblers at Fort Hood in the manner tested, and suggest that removal of smaller trees from the understory in a way that replicates historic conditions may elicit neutral responses from this forest-dependent songbird. Quantifying wildlife responses to military activities provides the Department of Defense and US Fish and Wildlife Service with data to guide conservation of threatened and endangered species on Department of Defense facilities while maintaining the military mission, and supports wildlife management efforts on other public and private lands.

  8. 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

  9. Using Landsat 8 imagery in detecting cork oak (Quercus suber L. woodlands: a case study in Calabria (Italy

    Directory of Open Access Journals (Sweden)

    Giuseppe Modica

    2016-12-01

    Full Text Available In the Mediterranean basin, cork oak (Quercus suber L. woodlands are characteristic and widespread forestry ecosystems. Though presenting significant economic potential as a renewable resource, they are not adequately valorised, in spite of a growing market demand for cork and cork-based products, which are appreciated, today, for their use in sustainable building. In this respect, cork meets the needs of the building industry in responding to the growing demand for quality products, which are eco- and energy-friendly and hygienically safe. Moreover, European cultural and biodiversity value has been attributed to cork oak woodlands and their most significant examples have been included in the Natura 2000 framework. So far, in some countries like Italy, the territorial distribution and characterisation of cork oak woodlands have not been adequately investigated. This study provides a method for mapping the actual presence of cork oak woodlands and for assessing their potential distribution. Special attention was given to the characterisation of cork oak spectral signature. To this end, Landsat 8 satellite images, digital photointerpretation and in situ surveys were implemented. The work carried out allows assessing the effectiveness of GIS and remote sensing techniques coupled with ancillary data and tools, and their applicability for the development of a comprehensive mapping and monitoring system of cork oak woodlands in Mediterranean ecosystems. Such techniques are vital to develop a detailed management strategy and to assist restoration activities and the economic assessment of semi-natural habitats. A case study, carried out in two different locations in Calabria (Italy, is provided.

  10. Spatial distribution of oak mistletoe as it relates to habits of oak woodland frugivores.

    Directory of Open Access Journals (Sweden)

    Ethan A Wilson

    Full Text Available This study addresses the underlying spatial distribution of oak mistletoe, Phoradendron villosum, a hemi-parasitic plant that provides a continuous supply of berries for frugivorous birds overwintering the oak savanna habitat of California's outer coast range. As the winter community of birds consuming oak mistletoe varies from group-living territorial species to birds that roam in flocks, we asked if mistletoe volume was spatially autocorrelated at the scale of persistent territories or whether the patterns predicted by long-term territory use by western bluebirds are overcome by seed dispersal by more mobile bird species. The abundance of mistletoe was mapped on trees within a 700 ha study site in Carmel Valley, California. Spatial autocorrelation of mistletoe volume was analyzed using the variogram method and spatial distribution of oak mistletoe trees was analyzed using Ripley's K and O-ring statistics. On a separate set of 45 trees, mistletoe volume was highly correlated with the volume of female, fruit-bearing plants, indicating that overall mistletoe volume is a good predictor of fruit availability. Variogram analysis showed that mistletoe volume was spatially autocorrelated up to approximately 250 m, a distance consistent with persistent territoriality of western bluebirds and philopatry of sons, which often breed next door to their parents and are more likely to remain home when their parents have abundant mistletoe. Using Ripley's K and O-ring analyses, we showed that mistletoe trees were aggregated for distances up to 558 m, but for distances between 558 to 724 m the O-ring analysis deviated from Ripley's K in showing repulsion rather than aggregation. While trees with mistletoe were aggregated at larger distances, mistletoe was spatially correlated at a smaller distance, consistent with what is expected based on persistent group territoriality of western bluebirds in winter and the extreme philopatry of their sons.

  11. Is cork oak (Quercus suber L. woodland loss driven by eucalyptus plantation? A case-study in southwestern Portugal

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    Costa A

    2014-06-01

    Full Text Available Mediterranean landscapes with open cork oak (Quercus suber L. woodlands have recently experienced drastic changes in southwestern Portugal. Changes in agricultural activities, the traditional driver of the economy in this region, led to new land uses, such as long-term set aside (shrublands and eucalyptus plantations. A study was conducted on the oak woodland landscape dynamics over a 50-year period (from 1958 to 2007 in order to assess the effect of different biophysical conditions on landscape spatial changes, and to identify the resilience of lanscape composition to different disturbances (e.g., socio-economic changes and wildfires. Land use changes over two consecutive periods (1958-1995 and 1995-2007 were inferred by spatial analysis of land cover data (aerial photographs and related to landscape physical attributes (slope and soil type. A transition matrix of four vegetation land-cover classes was obtained, allowing the assessment of the landscape composition changes bewteen the two above periods. Results showed that lansdcape in 1958 was largely occupied by open farmland, with large patches of open oak woodlands on steep slopes surrounding watercourses. Open farmland and shrubland drastically declined from 1958 to 1995, while eucalyptus plantation exhibited a dramatic expansion. Although large areas of cork oak forest turned into eucalyptus plantation, the net loss of oak forest was low and counterbalanced by its increment on former open farmland. The occurrence of a wildfire in 2003 promoted a dramatic decrease in cork oak woodlands, which mostly turned into shrubland. However, shrubland may be considered “safe sites” for ecological succession, ensuring natural cork oak regeneration and the colonisation of neighboring areas.

  12. Holocene semi-arid oak woodlands in the Irano-Anatolian region of Southwest Asia: natural or anthropogenic?

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    Asouti, Eleni; Kabukcu, Ceren

    2014-04-01

    It is commonly accepted that, following the end of the Pleistocene, semi-arid deciduous oak woodlands did not spread in the Irano-Anatolian region of Southwest Asia as quickly as they did in the Levantine Mediterranean littoral, despite the fact that climatic improvement occurred broadly at the same time in both regions. Prehistoric impacts on woodland vegetation (such as woodcutting, burning and clearance for cultivation), the harsh continental climate of inland Southwest Asia and its distance from late Pleistocene arboreal refugia have all been discussed in the literature as likely causes of the delay. In this paper we argue that semi-arid deciduous oak woodlands should not be viewed as part of the “natural” vegetation of the Irano-Anatolian region that has been progressively destroyed by millennia of human activities since the Neolithic. They represent instead one of the earliest anthropogenic vegetation types in Southwest Asia, one that owes its very existence to prehistoric landscape practices other scholars commonly label as “destructive”. Drawing on anthracological, pollen and modern vegetation data from central Anatolia we describe how the post-Pleistocene species-rich and structurally diverse temperate semi-arid savanna grasslands were gradually substituted by low-diversity, even-aged Quercus-dominated parklands and wood pastures in the course of the early Holocene. Economic strategies that encouraged the establishment and spread of deciduous oaks included sheep herding that impacted on grass and forb vegetation, the controlling of competing arboreal vegetation through woodcutting, and woodland management practices such as coppicing, pollarding and shredding that enhanced Quercus vegetative propagation, crown and stem growth. Understanding the origin and evolution of the Irano-Anatolian semi-arid oak woodlands of Southwest Asia is of critical importance for reconstructing the changing ecologies and geographical distributions of the progenitors of

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

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    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

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

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    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

  15. Litter leachate sources for streamwater dissolved organic matter in an oak woodland catchment

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    Dyda, R. Y.; Hernes, P. J.; Flores, S. C.; O'Geen, A. T.; Dahlgren, R. A.; Spencer, R.

    2009-12-01

    Streamwater dissolved organic matter (DOM) is derived from a variety of sources, but until recently was largely thought to originate from degraded soil organic matter (SOM) pools. However, recent investigations of dissolved organic carbon (DOC) have called into question the idea that DOM in streams is derived primarily from aged SOM. Evidence includes riverine DOC 14C ages (~5 years) that are much younger than SOM within the catchment as well as the riverine particulate organic matter (POM) pool (decades to 100’s of years). Molecular fractionation due to litter leaching in the laboratory and sorption to mineral surfaces can completely account for the degraded molecular signatures observed in dissolved lignin compositions within the DOM pool. To evaluate whether these processes hold true under environmental conditions, we conducted a leaching incubation experiment using litters and degraded “duff” litters (estimated 2-5 yrs of degradation) from four vegetation types (live and blue oak leaves, foothill pine needles, and mixed annual grasses) in an oak woodland ecosystem in the foothills of the Sierra mountains of California. Litters and duffs were placed on sieves within funnels throughout the catchment, and leachates were collected during each rainfall event from Dec. 1, 2006 through May 31, 2007. On a bulk carbon basis, duff material yielded the greatest flux of DOC and weighted average carbon normalized lignin yields and ratios of syringyl and cinnamyl phenols to vanillyl phenols were remarkably similar to that observed in the stream, indicating that processes such as sorption may not be the driving force behind the composition observed. However, elevated ratios of acid to aldehyde compounds of the syringyl and vanillyl phenols in the stream relative to the weighted average of the litter leachate as well as the litter and duff materials indicates that some modification of the lignin phenols. Areal yields of DOM are up to two orders of magnitude greater than

  16. Litter dominates surface fluxes of carbonyl sulfide in a Californian oak woodland

    Science.gov (United States)

    Sun, Wu; Maseyk, Kadmiel; Lett, Céline; Seibt, Ulli

    2016-02-01

    Carbonyl sulfide (COS) is a promising tracer for partitioning terrestrial photosynthesis and respiration from net carbon fluxes, based on its daytime co-uptake alongside CO2 through leaf stomata. Because ecosystem COS fluxes are the sum of plant and soil fluxes, using COS as a photosynthesis tracer requires accurate knowledge of soil COS fluxes. At an oak woodland in Southern California, we monitored below-canopy surface (soil + litter) COS and CO2 fluxes for 40 days using chambers and laser spectroscopy. We also measured litter fluxes separately and used a depth-resolved diffusion-reaction model to quantify the role of litter uptake in surface COS fluxes. Soil and litter were primarily COS sinks, and mean surface COS uptake was small (˜1 pmol m-2 s-1). After rainfall, uptake rates were higher (6-8 pmol m-2 s-1), and litter contributed a significant fraction (up to 90%) to surface fluxes. We observed rapid concurrent increases in COS uptake and CO2 efflux following the onset of rain. The patterns were similar to the Birch effect widely documented for soils; however, both COS and CO2 flux increases originated mainly in the litter. The synchronous COS-CO2 litter Birch effect indicates that it results from a rapid increase in litter microbial activity after rainfall. We expect that the drying-rewetting cycles typical for mediterranean and other semiarid ecosystems create a pronounced seasonality in surface COS fluxes. Our results highlight that litter uptake is an important component of surface COS exchange that needs to be taken into account in ecosystem COS budgets and model simulations.

  17. Partitioning water and carbon fluxes in a Mediterranean oak woodland using stable oxygen isotopes

    Science.gov (United States)

    Dubbert, Maren; Piayda, Arndt; Cuntz, Matthias; Correia, Alexandra; Silva, Filipe Costa e.; Pereira, Joao; Werner, Christiane

    2014-05-01

    Water is a key factor driving ecosystem productivity, especially in water-limited ecosystems. A separation of the component fluxes is needed to gain a functional understanding on the development of net ecosystem water fluxes and their coupling with biogeochemical cycles. Oxygen isotope signatures are valuable tracers for water movements within the ecosystem because of the distinct isotopic compositions of water in soil and vegetation. In the past, determination of isotopic signatures of evaporative or transpirational fluxes has been challenging since measurements of water vapor isotopes were difficult to obtain using cold-trap methods, delivering data with low time resolution. Recent developments in laser spectroscopy now enable direct high frequency measurements of the isotopic composition of atmospheric water vapor (δv), evapotranspiration (δET), and its components and allow validations of common modeling approaches for estimating δE and δT based on Craig and Gordon (1965). Here, a novel approach was used, combining a custom build flow-through gas-exchange branch chamber with a Cavity Ring-Down Spectrometer in a Mediteranean cork-oak woodland where two vegetation layers respond differently to drought: oak-trees (Quercus suber L.) avoid drought due to their access to ground water while herbaceous plants survive the summer as seeds. We aimed at 1) testing the Craig and Gordon equation for soil evaporation against directly measured δE and 2) quantifying the role of non-steady-state transpiration under natural conditions. Thirdly, we used this approach to quantify the impact of the understory herbaceous vegetation on ecosystem carbon and water fluxes throughout the year and disentangle how ET components of the ecosystem relate to carbon dioxide exchange. We present one year data comparing modeled and measured stable oxygen isotope signatures (δ18O) of soil evaporation, confirming that the Craig and Gordon equation leads to good agreement with measured δ18O of

  18. Land use practices and ectomycorrhizal fungal communities from oak woodlands dominated by Quercus suber L. considering drought scenarios.

    Science.gov (United States)

    Azul, Anabela Marisa; Sousa, João Paulo; Agerer, Reinhard; Martín, María P; Freitas, Helena

    2010-02-01

    Oak woodlands in the Mediterranean basin have been traditionally converted into agro-silvo-pastoral systems and exemplified sustainable land use in Europe. In Portugal, in line with the trend of other European countries, profound changes in management options during the twentieth century have led to landscape simplification. Landscapes are dynamic and the knowledge of future management planning combining biological conservation and soil productivity is needed, especially under the actual scenarios of drought and increasing evidence of heavy oak mortality. We examined the ectomycorrhizal (ECM) fungal community associated with cork oak in managed oak woodlands (called montado) under different land use practices, during summer. ECM fungal richness and abundance were assessed in 15 stands established in nine montados located in the Alentejo region (southern Portugal), using morphotyping and ITS rDNA analysis. Parameters related to the montados landscape characteristics, land use history over the last 25 years, climatic and edaphic conditions were taken into account. Fifty-five ECM fungal taxa corresponding to the most abundant fungal symbionts were distinguished on cork oak roots. Cenococcum geophilum and the families Russulaceae and Thelephoraceae explained 56% of the whole ECM fungal community; other groups were represented among the community: Cortinariaceae, Boletaceae, Amanita, Genea, Pisolithus, Scleroderma, and Tuber. There were pronounced differences in ECM fungal community structure among the 15 montados stands: C. geophilum was the only species common to all stands, tomentelloid and russuloid species were detected in 87-93% of the stands, Cortinariaceae was detected in 60% of the stands, and the other groups were more unequally distributed. Ordination analysis revealed that ECM fungal richness was positively correlated with the silvo-pastoral exploitation regime and low mortality of cork oak, while ECM fungal abundance was positively correlated with extensive

  19. Monitoring for pests and diseases in native oak woodlands: the case of acute oak decline in the United Kingdom

    Science.gov (United States)

    Nathan Brown; Stephen Parnell; Frank van den Bosch; Mike Jeger; Sandra Denman

    2017-01-01

    In recent years, a novel form of decline has been observed in southern and central England. This syndrome has been termed acute oak decline (AOD) and affects native oak, Quercus petraea and Q. robur. Typical symptoms include bark cracks that weep dark exudates, which are caused by necrotic patches in the...

  20. The impact of changes in the amount and timing of precipitation on the herbaceous understorey of Mediterranean evergreen oak woodlands

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    Jongen, Marjan; Lecomte, Xavier; Pereira, João. S.

    2010-05-01

    In the Iberian Peninsula, the evergreen oak woodlands, called montados in Portugal and dehesas in Spain, are of great ecological and socio-economic importance. Dominated by evergreen Quercus species, these savanna-type woodlands are characterized by a widely separated tree stratum associated with an herbaceous understorey, dominated by C3 annual species. The productivity and biogeochemical cycles of the herbaceous layer are highly dependent on timing and magnitude of precipitation. Climate change scenarios for the region suggest not only increasing air temperatures, but also the possibility of decreasing spring precipitation, accompanied by an increase in the interval between precipitation events, which might cause drought conditions to occur. To understand the impact of hydrological changes on productivity and ecosystem processes of the herbaceous understorey in these ecosystems, water manipulation experiments are being carried out in Portugal. In autumn 2009, large (30 m2) rain-out shelters were constructed near Coruche (Portugal), with the aim of studying the effect of precipitation variability on the understorey vegetation in a managed cork oak woodland. Initially, the two treatments in the rain-out shelters will be: (1) ambient precipitation quantity, with a dry period of 7 days, and (2) ambient precipitation quantity with a dry period of 21 days. The 'ambient precipitation quantity' is based on historical precipitation data for the experimental site, with average annual precipitation of 680 mm. In addition to the above two treatments, there will be non-sheltered reference plots, receiving natural rainfall patterns. In the future we aim to reduce the precipitation quantity (-30%) with similar length of the dry periods as above. From February 2010 onwards, we will gather a full data set for environmental variables, as well as productivity, species composition, soil CO2 flux, soil nitrogen and photosynthesis. Preliminary results will be presented.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    Alla eShvaleva

    2015-10-01

    Full Text Available 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 gas fluxes 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 gene 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, SOM had a positive effect on soil extracellular enzyme activities (EEA, 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.

  3. 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.

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

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    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.

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

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    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.

  6. 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)

  7. 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.

  8. 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.

  9. Evaluation of wildlife-habitat relationships data base for predicting bird community composition in central California chaparral and blue oak woodlands

    Science.gov (United States)

    Avery, M.L.; van Riper, Charles

    1990-01-01

    The California Wildlife-Habitat Relationships (WHR) database can be used to assist resource managers to evaluate effects of habitat manipulations on wildlife. The accuracy of predictions from WHR was evaluated using data from bird surveys conducted during winter and spring 1984 and 1985 in chamise (Adenostema fasciculata) chaparral, mixed chaparral and blue oak (Quercus douglasii) woodland. Considerable variability between habitat types was found for errors both of commission and of omission.

  10. Nitrogen inputs and losses in response to chronic CO2 exposure in a sub-tropical oak woodland

    Directory of Open Access Journals (Sweden)

    B. A. Hungate

    2014-01-01

    Full Text Available Rising atmospheric CO2 concentrations could alter the nitrogen (N content of ecosystems by changing N inputs and N losses, but responses vary in field experiments, possibly because multiple mechanisms are at play. We measured N fixation and N losses in a subtropical oak woodland exposed to 11 yr of elevated atmospheric CO2 concentrations. We also explored the role of herbivory, carbon limitation, and competition for light and nutrients in shaping response of N fixation to elevated CO2. Elevated CO2 did not significantly alter gaseous N losses, but lower recovery and deeper distribution in the soil of a long-term 15N tracer indicated that elevated CO2 increased leaching losses. Elevated CO2 had no effect on asymbiotic N fixation, and had a transient effect on symbiotic N fixation by the dominant legume. Elevated CO2 tended to reduce soil and plant concentrations of iron, molybdenum, phosphorus, and vanadium, nutrients essential for N fixation. Competition for nutrients and herbivory likely contributed to the declining response N fixation to elevated CO2. These results indicate that positive responses of N fixation to elevated CO2 may be transient, and that chronic exposure to elevated CO2 can increase N leaching. Models that assume increased fixation or reduced N losses with elevated CO2 may overestimate future N accumulation in the biosphere.

  11. Beyond CO2: Changes in Limiting Resources in California Oak Woodland

    Science.gov (United States)

    Hasselquist, N.; Allen, M.

    2007-12-01

    As atmospheric CO2 continues to increase, other resources become even more limiting to plants and the wildland ecosystems they support. Traditionally, California Mediterranean-type ecosystems are limited by water, then N. In these ecosystems, CO2 enrichment causes a minor increase in production associated with enhanced water-use efficiency, but N rapidly becomes the limiting factor to both production and to soil organism dynamics. In urbanizing areas, such as southern California, strong gradients in NOx deposition are also created by vehicular pollution. We have studied the regulation of N uptake by mycorrhizae in Coast Live Oak (Quercus agrifolia) using information with natural abundance from the early 1900s, current plants and fungi, and modeling change. Contrasts were made from a high NOx deposition site, a low deposition site, and a site where NOx deposition is rapidly increasing. We examined natural abundance δ15 N of current and past plant material (leaves, wood), mycorrhizal and saprobic fungal fruiting bodies, and soil. We modeled relative N uptake, fractionation, and transport between soil, fungus and plant. Our data show complex interactions between increasing NOx deposition and increasing atmospheric CO2 on mycorrhizal-plant interactions. There is a significant shift in N sources and reduction upon mycorrhizae with NOx deposition. However, the elevated CO2 appears to also have created a greater N demand on the trees, increasing dependence on mycorrhizae and the ability of the fungi to acquire organic N and NH4. The individual fungal species differ among sites, but complex trends between fungal genera and trees can be seen. Projections of increasing atmospheric CO2 and regional NOx deposition suggest strong but complex gradients in fungal-oak interactions with decreasing dependence on mycorrhizae near urbanizing areas, mediated by the rate of increasing CO2 and inorganic NOx deposition, and paradoxically, increasing dependency on mycorrhizae and organic

  12. 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.

  13. 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.

  14. Influence of tree canopy on N₂ fixation by pasture legumes and soil rhizobial abundance in Mediterranean oak woodlands.

    Science.gov (United States)

    Carranca, C; Castro, I V; Figueiredo, N; Redondo, R; Rodrigues, A R F; Saraiva, I; Maricato, R; Madeira, M A V

    2015-02-15

    Symbiotic N2 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, N2 fixation was evaluated in four oak woodlands under Mediterranean conditions using a split-plot design and three replicates. (15)N technique was used for determination of N2 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 N2 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(-1)yr(-1)). Overall, competition of pasture growth for light was negligible, but soil rhizobial abundance and symbiotic N2 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, N2 fixation capacity increased from about 0.10 kg N ha(-1) per day in the autumn-winter period to 0.15 kg N ha(-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.

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

    Directory of Open Access Journals (Sweden)

    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, Reco 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 Reco/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

  16. Abundance and Bloodfeeding Patterns of Mosquitoes (Diptera: Culicidae) in an Oak Woodland on the Eastern Slope of the Northern Coast Range of California.

    Science.gov (United States)

    Thiemann, Tara C; Woodward, David L; Fang, Ying; Ryan, Bonnie M; Nelms, Brittany M; Scott, Jamesina J; Reisen, William K

    2017-09-01

    The abundance and bloodfeeding patterns of mosquitoes was studied from 2008 to 2010 at an 18 ha. oak woodland in Lake County, CA. Host-seeking females were collected weekly from sunset to sunrise by paired dry-ice-baited CDC style traps, whereas resting females were aspirated from paired walk-in red boxes. Sequences of the COI gene amplified from bloodmeals from engorged resting females were used to identify the bloodmeal hosts. Aedes sierrensis (Ludlow) and Aedes increpitus Dyar complex mosquitoes were univoltine, although the timing of emergence and abundance varied temporally and seemed weather dependent. Abundance of both Anopheles franciscanus McCracken and Anopheles freeborni Aitken peaked in mid to late summer. Females of both genera bloodfed primarily on mule deer and black-tailed jackrabbits, and few fed on either dogs or humans that were consistently present within the woodland. In contrast, multivoltine Culex tarsalis Coquillett and Culex stigmatosoma Dyar were abundant throughout summer, especially from July to September. Both Culex species bloodfed on a wide variety of avian hosts, with most bloodmeals originating from California scrub-jay, wild turkey, oak titmouse, and house finch. Culex tarsalis fed on proportionately more mammals as summer progressed, peaking at 33% in September. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. US Forest Service Historical Woodland Density of the Conterminous United States, 1873

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map service on the www that includes polygons with a minimum of 40 acres of woodlands per square mile as depicted in William H. Brewer’s 1873 map of woodland...

  18. In situ spectral measurements improve the efficiency of light use efficiency models to estimate gross primary productivity in Mediterranean cork oak woodland

    Science.gov (United States)

    Cerasoli, S.; Silva, J. M.; Carvalhais, N.; Correia, A.; Costa e Silva, F.; Pereira, J. S.

    2013-12-01

    The Light Use Efficiency (LUE) concept is usually applied to retrieve Gross Primary Productivity (GPP) estimates in models integrating spectral indexes, namely Normalized Difference Vegetation Index (NDVI) and Photochemical Reflectance Index (PRI), considered proxies of biophysical properties of vegetation. The integration of spectral measurements into LUE models can increase the robustness of GPP estimates by optimizing particular parameters of the model. NDVI and PRI are frequently obtained by broad band sensors on remote platforms at low spatial resolution (e.g. MODIS). In highly heterogeneous ecosystems such spectral information may not be representative of the dynamic response of the ecosystem to climate variables. In Mediterranean oak woodlands different plant functional types (PFT): trees canopy, shrubs and herbaceous layer, contribute to the overall Gross Primary Productivity (GPP). In situ spectral measurements can provide useful information on each PFT and its temporal variability. The objectives of this study were: i) to analyze the temporal variability of NDVI, PRI and others spectral indices for the three PFT, their response to climate variables and their relationship with biophysical properties of vegetation; ii) to optimize a LUE model integrating selected spectral indexes in which the contribution of each PFT to the overall GPP is estimated individually; iii) to compare the performance of disaggregated GPP estimates and lumped GPP estimates, evaluated against eddy covariance measurements. Ground measurements of vegetation reflectance were performed in a cork oak woodland located in Coruche, Portugal (39°8'N, 8°19'W) where carbon and water fluxes are continuously measured by eddy covariance. Between April 2011 and June 2013 reflectance measurements of the herbaceous layer, shrubs and trees canopy were acquired with a FieldSpec3 spectroradiometer (ASD Inc.) which provided data in the range of 350-2500nm. Measurements were repeated approximately on

  19. 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

  20. Impact of herbaceous understory vegetation to ecosystem water cycle, productivity and infiltration in a semi arid oak woodland assessed by stable oxygen isotopes

    Science.gov (United States)

    Dubbert, Maren; Piayda, Arndt; Silva, Filipe Costa e.; Correia, Alexandra C.; Pereira, Joao S.; Cuntz, Matthias; Werner, Christiane

    2015-04-01

    Water is one of the key factors driving ecosystem productivity, especially in water-limited ecosystems. Thus a separation of these component fluxes is needed to gain a functional understanding on the development of net ecosystem water and carbon fluxes. Oxygen isotope signatures are valuable tracers for such water movements within the ecosystem because of the distinct isotopic compositions of water in the soil and vegetation. Here, a novel approach was used (Dubbert et al., 2013), combining a custom build flow-through gas-exchange branch chamber with a Cavity Ring-Down Spectrometer in a Mediterranean cork-oak woodland where two vegetation layers respond differently to drought: oak-trees (Quercus suber L.) avoid drought due to their access to ground water while herbaceous plants survive the summer as seeds. We used this approach to quantify the impact of the understory herbaceous vegetation on ecosystem carbon and water fluxes throughout the year and disentangle how ET components of the ecosystem relate to carbon dioxide exchange. Partitioning ecosystem ET and NEE into its three sources revealed that understory vegetation contributed markedly to ecosystem ET and gross primary production (GPP; max. 43 and 51%, respectively). It reached similar water-use efficiencies (WUE) as cork-oak trees and significantly contributed to the ecosystem sink-strength in spring and fall. The understory vegetation layer further strongly inhibited soil evaporation (E) and, although E was large during wet periods, it did not diminish ecosystem WUE during water-limited times (Dubbert et al., 2014a). Although, during most of the year, interactions with trees neither facilitated nor hampered the development of the understory vegetation, strong competition for water could be observed at the end of the growing period, which shortened the life-cycle of understory plants and significantly reduced the carbon uptake of the ecosystem in spring (Dubbert et al., 2014b). Finally, herbaceous understory

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

    Science.gov (United States)

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

    2016-01-01

    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,...

  2. Does nest site availability limit the density of hole nesting birds in small woodland patches?

    Directory of Open Access Journals (Sweden)

    J. Loman

    2006-11-01

    Full Text Available By providing nest boxes, previous studies have shown that nest sites are in short supply and limit the populations of several small passerines, including the Great Tit Parus major, the Blue Tit P. caeruleus, and the Pied Flycatcher Ficedula hypoleuca. Can this influence their distribution over a range of small woodland patch sizes in a heterogeneous landscape? To investigate this, a study was conducted in a heterogeneous agricultural landscape, with a mixture of wooded patches and cropped fields, in southern Sweden. The descriptive part of the study involved mapping territories of the three species in 135 patches. These species avoided small (<1 ha, Pied Flycatcher or very small (<0.2 ha, the two tit species forest patches in this landscape. In an experimental part, a subset of 34 patches, 0.01 to 24 ha in size was used. Territories were mapped in a first year as a control. In a second year, patches were matched by size and vegetation and nest-boxes were provided in one patch of each pair. Territories were again mapped. Providing nestboxes increased the density of breeding Great Tits in patches of all sizes and expanded their use of very small patches. The nest-boxes increased the density of Pied Flycatchers in large patches but not in small patches. So, is the lack of territories in small patches due to shortage of nest sites? The outcome of the experiment suggests nest site limitation as a cause of the observed Great Tit discrimination against very small habitat patches. The lack of Pied Flycatchers in small patches must however have another basis than lack of nest sites. The effect of providing nest-boxes on Blue Tit distribution was inconclusive.

  3. 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.

  4. Density and Distribution of Citemene Fields in a Miombo Woodland Environment in Zambia.

    Science.gov (United States)

    Sprague; Oyama

    1999-09-01

    / The Bemba people of northern Zambia practice citemene shifting cultivation. We utilized Landsat satellite images from 1984 and 1992 to map the distribution of citemene fields in those two years and to assess changes in the spatial sustainability of citemene cultivation in a miombo woodland study area. The citemene fields were concentrated within about 5-6 km of roads. Between 1984 and 1992, there was a decrease in the number of fields, and an increase in the average distance from the road. These changes may have been due to the introduction of semipermanent maize farming in the intervening years. The estimated cycle times for woodland utilization may have been long enough to maintain sustainability under traditional citemene cultivation practices. However, cycle times may be too short to maintain sustainability within the woodlands along roads.KEY WORDS: Shifting agriculture; GIS; Sustainability; Citemene; Miombo; Zambiahttp://link.springer-ny.com/link/service/journals/00267/bibs/24n2p273.html

  5. Linking water and carbon fluxes in a Mediterranean oak woodland using a combined flux and ?18O partitioning approach

    Science.gov (United States)

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

    2013-12-01

    Water is one of the key factors driving ecosystem productivity, especially in water-limited ecosystems, where global climate change is expected to intensify drought and alter precipitation patterns. One such ecosystem is the ';Montado', where two vegetation layers respond differently to drought: oak trees avoid drought due to their access to deeper soil layers and ground water while herbaceous plants, surviving the summer in the form of seeds. We aimed at 1) quantifying the impact of the understory herbaceous vegetation on ecosystem carbon and water fluxes throughout the year, 2) determining the driving environmental factors for evapotranspiration (ET) and net ecosystem exchange (NEE) and 3) disentangling how ET components of the ecosystem relate to carbon dioxide exchange. We present one year data set comparing modeled and measured stable oxygen isotope signatures (δ18O) of soil evaporation, confirming that the Craig and Gordon equation leads to good agreement with measured δ18O of evaporation (Dubbert et al. 2013). Partitioning ecosystem ET and NEE into its three sources revealed a strong contribution of soil evaporation (E) and herbaceous transpiration (T) to ecosystem ET during spring and fall. In contrast, soil respiration (R) and herbaceous net carbon gain contributed to a lesser amount to ecosystem NEE during spring and fall, leading to consistently smaller water use efficiencies (WUE) of the herbaceous understory compared to the cork-oaks. Here, we demonstrate that the ability to assess ET, NEE and WUE independent of soil evaporation dynamics enables the understanding of the mechanisms of the coupling between water and carbon fluxes and their responses to drought. Dubbert, M., Cuntz, M., Piayda, A., Maguas, C., Werner, C., 2013: Partitioning evapotranspiration - Testing the Craig and Gordon model with field measurements of oxygen isotope ratios of evaporative fluxes. J Hydrol. a) Oxygen isotope signatures of soil evaporation on bare soil plots calculated

  6. Why is cultural resource site density high in the pinon-juniper woodland?

    Science.gov (United States)

    Sarah Schlanger; Signa Larralde

    2008-01-01

    (Please note, this is an extended abstract only) Hunter gatherers relied on healthy pinon-juniper woodland because it supports a wide variety of small game, large game, and bird species that shelter in the trees and forage on pinon nuts, a rich food source for humans as well as game.

  7. Effects of management thinning on CO2 exchange by a plantation oak woodland in south-eastern England

    Science.gov (United States)

    Wilkinson, Matthew; Crow, Peter; Eaton, Edward L.; Morison, James I. L.

    2016-04-01

    Forest thinning, which removes some individual trees from a forest stand at intermediate stages of the rotation, is commonly used as a silvicultural technique and is a management practice that can substantially alter both forest canopy structure and carbon storage. Whilst a proportion of the standing biomass is removed through harvested timber, thinning also removes some of the photosynthetic leaf area and introduces a large pulse of woody residue (brash) to the soil surface, which potentially can alter the balance of autotrophic and heterotrophic respiration. Using a combination of eddy covariance (EC) and aerial light detection and ranging (lidar) data, this study investigated the effects of management thinning on the carbon balance and canopy structure in a commercially managed oak plantation in the south-east of England. Whilst thinning had a large effect on the canopy structure, increasing canopy complexity and gap fraction, the effects of thinning on the carbon balance were not as evident. In the first year post thinning, the peak summer photosynthetic rate was unaffected by the thinning, suggesting that the better illuminated ground vegetation and shrub layer compensated for the removed trees. Peak summer photosynthetic rate was reduced in the thinned area between 2009 and 2011, but there was no significant difference between sectors. Ecosystem respiration fluxes increased in the thinned relative to the unthinned area in the post-thinning phase.

  8. Effects of management thinning on CO2 exchange by a plantation oak woodland in south-eastern England

    Science.gov (United States)

    Wilkinson, M.; Crow, P.; Eaton, E. L.; Morison, J. I. L.

    2015-10-01

    Forest thinning, which removes some individual trees from a forest stand at intermediate stages of the rotation, is commonly used as a silvicultural technique and is a management practice that can substantially alter both forest canopy structure and carbon storage. Whilst a proportion of the standing biomass is removed through harvested timber, thinning also removes some of the photosynthetic leaf area and introduces a large pulse of woody residue (brash) to the soil surface which potentially can alter the balance of autotrophic and heterotrophic respiration. Using a combination of eddy covariance (EC) and aerial light detection and ranging (LiDAR) data, this study investigated the effects of management thinning on the carbon balance and canopy structure in a commercially managed oak plantation in the south-east of England. Whilst thinning had a large effect on the canopy structure, increasing canopy complexity and gap fraction, the effects of thinning on the carbon balance were not as evident. In the first year post thinning, Net Ecosystem Exchange (NEE) was unaffected by the thinning, suggesting that the better illuminated ground vegetation and shrub layer partially compensated for the removed trees. NEE was reduced in the thinned area but not until two years after the thinning had been completed (2009); initially this was associated with an increase in ecosystem respiration (Reco). In subsequent years, NEE remained lower with reduced carbon sequestration in fluxes from the thinned area, which we suggest was in part due to heavy defoliation by caterpillars in 2010 reducing GPP in both sectors of the forest, but particularly in the east.

  9. [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.

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

    Directory of Open Access Journals (Sweden)

    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

  11. 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

  12. Facilitation of Quercus ilex recruitment by shrubs in Mediterranean open woodlands

    NARCIS (Netherlands)

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

    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

  13. Group Dynamics of Zebra and Wildebeest in a Woodland Savanna: Effects of Predation Risk and Habitat Density

    OpenAIRE

    Maria Thaker; Vanak, Abi T.; Cailey R. Owen; Monika B. Ogden; Rob Slotow

    2010-01-01

    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...

  14. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

  17. Baskett Slough/William L. Finley - Oregon White Oak Restoration, Douglas-fir Removal, Phase III

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — With less than 7% of historic oak woodland habitat and 1% of oak savanna currently remaining in the Willamette Valley, the WV NWRC holds some of the largest and best...

  18. Fire in Eastern North American Oak Ecosystems: Filling the Gaps

    Science.gov (United States)

    Julian (Morgan) Varner; Mary Arthur; Stacy Clark; Daniel C. Dey; Justin Hart; Callie Schweitzer

    2016-01-01

    This special issue of Fire Ecology is focused on the fire ecology of eastern USA oak (Quercus L.) forests, woodlands, and savannas. The papers were presented as part of the Fifth Fire in Eastern Oak Forests Conference in Tuscaloosa, Alabama, USA, in 2015. The topic of fire in eastern oak ecosystems is one that has received insufficient interest from the...

  19. Organic C distribution and N mineralization in soil of oak woodlands with improved pastures Distribuição espacial do C orgânico e da mineralização de N em solos de montado com pastagem melhorada

    Directory of Open Access Journals (Sweden)

    Maria Xesús Gómez-Rey

    2011-01-01

    Full Text Available Cork oak woodlands in Portugal are a multipurpose agroforestry system occurring in areas mostly degraded by former cereal crops and overgrazing. The objective of this study was to evaluate the effect of scattered cork oak trees (Quercus suber L. on soil quality, considering two land use systems: unmanaged pastures and improved pastures. Soil samples were collected in a square grid around scattered cork oak trees to evaluate the spatial variability of soil bulk density and chemical properties. In soil samples taken beneath tree canopy and in the open, net N mineralization was evaluated by aerobic incubations. Also, laboratory incubations were carried out to evaluate the effect of roots (tree or/and herbaceous and water solutions (bulk precipitation, throughfall or stemflow on net N mineralization.Contents of organic C, total N and extractable P were increased beneath the tree canopy, and gradually decreased with the increase of distance to the tree trunk. Improved pastures established 26 years ago increased organic C (0.76 kg m-2, total N (0.06 kg m-2 and extractable P (2.70 g m-2 amounts in the 0-10 cm soil layer beneath the tree canopy relatively to those of unmanaged pastures. Net N mineralization was significantly greater (about 2 times in soils beneath the tree canopy than in those of open areas. N mineralization was unaffected by addition of throughfall or stemflow, while a significant reduction resulted from tree roots addition, this effect being stronger for herbaceous plant roots than for tree roots. Maintenance of tree cover combined with permanent improved pastures should be considered to improve soil quality in oak woodlands of Southern Portugal.O montado em Portugal corresponde a um sistema multifuncional que ocorre em áreas frequentemente degradadas pelo cultivo de cereais e de sobre pastoreio. O objectivo deste estudo foi avaliar a influência das árvores espaçadas na variação do C orgânico, N total e P extraível num montado

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

    Science.gov (United States)

    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...

  1. Transpiration of oak trees in the oak savannas of the Southwestern Borderlands region

    Science.gov (United States)

    Peter F. Ffolliott; Cody L. Stropki; Aaron T. Kauffman; Gerald J. Gottfried

    2008-01-01

    Transpiration of oak trees on the Cascabel watersheds in the savannas on the eastern slope of the Peloncillo Mountains in southwestern New Mexico has been estimated by the sap-flow method. Transpiration represents the largest loss of gross precipitation falling on a watershed in approximations of water budgets for the more densely stocked oak woodlands of the...

  2. 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...

  3. 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.

  4. 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. D

  5. Tree Species Richness and Stand Productivity in Low-Density Cluster Plantings with Oaks (Quercus robur L. and Q. petraea (Mattuschka Liebl.

    Directory of Open Access Journals (Sweden)

    Christian Kuehne

    2013-08-01

    Full Text Available Low density plantings complemented by natural regeneration is an increasingly common reforestation technique to ensure growth of a sufficient number of trees from desired species while maintaining natural processes such as succession. One such form of low density planting that aims at lowering establishment costs—oak clusters—has been developed as an alternative to row planting since the 1980s in central Europe. However, whether cluster planting provides higher species richness and productivity than high density row planting has not previously been analyzed. Here, we compare tree species richness and productivity (measured as stand basal area between oak cluster plantings and conventional row planting in young (10–26 years old forest stands at seven study sites in Germany. Tree species richness was significantly higher in cluster plantings than in row plantings, whereas total basal areas were comparable. Naturally regenerated trees contributed on average to 43% of total stand basal area in cluster plantings, which was significantly higher than in row plantings. Total stand basal area in cluster planting was significantly related to the density of naturally regenerated trees. In turn, tree species diversity, density and basal area of naturally regenerated trees were increased with the size of unplanted area between clusters. Our results demonstrate that the admixture of naturally regenerated, early and mid-successional tree species compensates for a possible loss in productivity from planting fewer oaks. Low density cluster plantings can offer significant environmental benefits, at least for the first few decades of stand development, without compromising productivity.

  6. Using 13C and 15N isotopes to study allocation patterns in oak seedlings

    Science.gov (United States)

    Laura M. Suz; María V. Albarracín; Caroline S. Bledsoe

    2008-01-01

    In California’s oak woodlands, survival and growth of oaks may depend on a symbiosis between oak roots and fungi that form ectomycorrhizas. Ectomycorrhizal (ECM) fungi are major players in carbon (C) and nitrogen (N) utilization and cycling because they facilitate water and nutrient uptake from the soil into the plant. The ECM fungi also benefit because plants supply...

  7. Symptoms of the naturalisation of the Turkey oak (Quercus cerris L. in Polish forests

    Directory of Open Access Journals (Sweden)

    Danielewicz Władysław

    2016-09-01

    Full Text Available The Turkey oak (Quercus cerris L., the natural range of which embraces southern Europe and Asia Minor, belongs to trees rarely introduced into Polish forests. Tree stands where it appears, established before the Second World War, can be found in some 20 localities, mostly in the western part of the country. Because this species is capable of a natural renewal in a woodland environment, a research was made to find in what conditions and how far it undergoes spontaneous naturalisation. Three study sites were chosen in the forests of central Wielkopolska. An inventory was made of mature stands of the Turkey oak and its generative renewal. Plant communities in which the young generation of Q. cerris usually appears were characterised. It was found that self-sown seedlings of this species grew at a distance of up to 2,500 m from parent trees. The highest number and the greatest density of specimens of the secondary generation of the Turkey oak were found at ‘Racot’, which is a 100-hectare, mid-field woodland island where mesotrophic habitats predominate and where about 50% of the area is occupied by communities with manmade pine tree stands. At all sites, Q. cerris penetrates primarily this type of deformed phytocoenoses, developing mostly on former farmland. It has become a permanent component of the underbrush and undergrowth in them, and in some places, it also makes up the tree layer. It was observed that in the study area, it penetrated the woodland environment much more effectively than Quercus rubra, considered an invasive species. The expansion of the Turkey oak in several of the examined localities can be regarded as a basic manifestation of its naturalisation in places where there are phytocoenoses with pine stands in broad-leaf forest habitats in the neighbourhood of parent trees.

  8. Early and long-term impacts of browsing by roe deer in oak coppiced woods along a gradient of population density

    Directory of Open Access Journals (Sweden)

    Francesco Chianucci

    2015-01-01

    Full Text Available Over the last few decades, wild ungulate populations have exhibited relevant geographic and demographic expansion in most European countries; roe deer is amongst the most widespread ungulate species. The increasing roe deer densities have led to strong impact on forest regeneration; the problem has been recently recognized in coppice woods, a silvicultural system which is widespread in Italy, where it amounts to about 56% of the total national forested area.In this study we investigated the effect of roe deer browsing on the vegetative regeneration of Turkey oak few years after coppicing, along a gradient of roe deer density. A browsing index revealed that browsing impact was high at any given roe deer density but increased at higher density, with the browsing rate ranging from 65% to 79%. We also analyzed the long-term impact of browsing six and eleven years after coppicing under a medium roe deer density. Results indicated the early impact are not ephemeral but produced prolonged impacts through time, with an average reduction in volume of -57% and -41% six and eleven years after coppicing, respectively. Based on these results we proposed integrating browsing monitoring with roe deer density estimation to allow identifying ungulate densities which are compatible with silvicultural and forest management objectives. The proposed browsing index can be regarded as an effective management tool, on account of its simplicity and cost-effectiveness, being therefore highly suitable for routine, large scale monitoring of browsing impact.

  9. Single-nucleotide polymorphism discovery and validation in high-density SNP array for genetic analysis in European white oaks.

    Science.gov (United States)

    Lepoittevin, C; Bodénès, C; Chancerel, E; Villate, L; Lang, T; Lesur, I; Boury, C; Ehrenmann, F; Zelenica, D; Boland, A; Besse, C; Garnier-Géré, P; Plomion, C; Kremer, A

    2015-11-01

    An Illumina Infinium SNP genotyping array was constructed for European white oaks. Six individuals of Quercus petraea and Q. robur were considered for SNP discovery using both previously obtained Sanger sequences across 676 gene regions (1371 in vitro SNPs) and Roche 454 technology sequences from 5112 contigs (6542 putative in silico SNPs). The 7913 SNPs were genotyped across the six parental individuals, full-sib progenies (one within each species and two interspecific crosses between Q. petraea and Q. robur) and three natural populations from south-western France that included two additional interfertile white oak species (Q. pubescens and Q. pyrenaica). The genotyping success rate in mapping populations was 80.4% overall and 72.4% for polymorphic SNPs. In natural populations, these figures were lower (54.8% and 51.9%, respectively). Illumina genotype clusters with compression (shift of clusters on the normalized x-axis) were detected in ~25% of the successfully genotyped SNPs and may be due to the presence of paralogues. Compressed clusters were significantly more frequent for SNPs showing a priori incorrect Illumina genotypes, suggesting that they should be considered with caution or discarded. Altogether, these results show a high experimental error rate for the Infinium array (between 15% and 20% of SNPs potentially unreliable and 10% when excluding all compressed clusters), and recommendations are proposed when applying this type of high-throughput technique. Finally, results on diversity levels and shared polymorphisms across targeted white oaks and more distant species of the Quercus genus are discussed, and perspectives for future comparative studies are proposed.

  10. 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...

  11. 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.

  12. Ecological effect of planting density and woodland preparation in E.saligna x exserta%柳窿桉9号造林密度与整地生态效应研究

    Institute of Scientific and Technical Information of China (English)

    吴清金

    2011-01-01

    Ecological effect of planting density and woodland preparation in E. Saligna x exserta were investigated in the present work. Hie results showed that the effect of soil preparation specifications on the stand growth, wind resistance, soil fertility, vegetation and water conservation forest of E. Saligna × exserta were very limited, and no obvious interactions with the planting density and the soil preparation specifications were obtained. However, the effects of planting density on stand growth, wind resistance, soil fertility, forest vegetation and water conservation were significant, and played chief roles in wind resistance and yield. Basedon stand growth, wind resistance, soil fertility, forest vegetation diversity, water conservation, investment cost, and on condition that without obviously affect the growth and wind resistance of the plant, the planting density of 1110 ~ 1 320 tree per hm2 was comparatively appropriate for increase in productivity, enhancement of wind resistance, and maintenance of soil fertility.%对柳窿按9号的造林密度及整地生态效应进行研究.结果表明:整地规格对柳窿桉9号林分生长量、抗风性、土壤肥力、林下植被以及水源涵养的影响较小,而且其与造林密度互作对柳窿桉9号林分生长量及抗风性的效应不明显.但密度对林分生长量、抗风性、土壤肥力、林下植被以及水源涵养的影响却较大,是影响产量和抗风性的主要因素.综合林分生长量、抗风性、土壤肥力、林下植被多样性、水源涵养功能以及投资成本,在不严重影响生长量和抗风性的情况下,柳窿桉9号的造林整地挖穴规格以小规格(30 cm×20 cm×20cm)即可.而造林密度以1110~1320株/hm2较为适宜,不但有利于提高产量、增强抗风性且有利于地力维护.

  13. Topographic position modulates the mycorrhizal response of oak trees to interannual rainfall variability.

    Science.gov (United States)

    Querejeta, José I; Egerton-Warburton, Louise M; Allen, Michael F

    2009-03-01

    California coast live oak (Quercus agrifolia) forms tripartite symbiotic associations with arbuscular (AMF) and ectomycorrhizal (EMF) fungi. We selected oak individuals differing in topographic position and depth to groundwater (mesic valley vs. xeric hill sites) to investigate changes of tree mycorrhizal status in response to interannual rainfall variability. EMF root colonization, as well as hyphal abundance and viability in upper rhizosphere soil (0-30 cm), were negatively affected by severe multi-year drought, although not to the same extent in each topographic location. Oak trees growing in hill sites showed EMF colonization levels drought. By contrast, oaks in valley sites maintained much higher EMF colonization (>19%) in upper roots during drought. EMF root colonization increased sharply at both topographic positions during the ensuing wet year (78% in valley, 49% in hill), which indicates that the mycorrhizal status of roots in upper rhizosphere soil is highly responsive to interannual rainfall variability. Across sites and years, percentage EMF colonization and soil hyphal density and viability were strongly positively correlated with soil moisture potential, but percentage AMF root colonization was not. Interestingly, changes in percentage EMF root colonization and density of viable hyphae between a wet and a dry year were proportionally much greater in xeric hill sites than in mesic valley sites. The mycorrhizal status of oak trees was particularly responsive to changes in soil moisture at the hill sites, where roots in upper rhizosphere soil shifted from almost exclusively AMF during severe drought to predominantly EMF during the ensuing wet year. By contrast, the mycorrhizal status of oaks in the valley sites was less strongly coupled to current meteorological conditions, as roots in upper soil layers remained predominantly EMF during both a dry and a wet year. Canopy shading and hydraulic lift by oaks in valley sites likely contributed to maintain the

  14. Phylogenetic diversity of Moroccan cork oak woodlands fungi

    Directory of Open Access Journals (Sweden)

    Abourouh M.

    2009-01-01

    Full Text Available Interspecific variation among 87 sporocarps of fungi belonging to 15 genera and 39 species were evaluated by analyzing the internal transcribed spacer (ITS of the rDNA region using restriction fragment length polymorphism (RFLP. The ITS region was first amplified by polymerase chain reaction (PCR with specific primers and then cleaved with different restriction enzymes. Amplification products, which ranged between 500 and 950 base pairs (bp, were obtained for all the isolates analyzed. The degree of polymorphism observed did not allow proper identification of most of the species. Cleavage of amplified fragments with the restriction enzymes Alu I, EcoR I and Hinf I revealed extensive polymorphism. The fifteen genera and most species presented specific restriction patterns. The only species not identifiable by a specific pattern belonged to the genera Russula (R. decipiens and R. straminea. These species might be considered as closely related species. The Pisolithus sporocarps had two ITS-RFLP types with one dominating. ITS sequencing confirms that the two RFLP types correspond to two distinct species of Pisolithus. Our data show the potential of ITS region PCR-RFLP for the molecular characterization of ectomycorrhizal fungi and their identification and monitoring in artificial inoculation programs.

  15. Sustaining Oak Ecosystems in the Central Hardwood Region: Lessons from the Past--Continuing the History of Disturbance

    Science.gov (United States)

    Daniel C. Dey; Richard P. Guyette

    2000-01-01

    Oak savannas, woodlands and forests were dominant ecosystems throughout the central hardwood Region (CHR) before European settlement. Today, only 0.02 percent of the original oak savannas present at the time of European settlement remain, and bottomland hardwood forests have been reduced by 70 to 95 percent depending on the watershed (Nuzzo 1986, Sharitz and Mitsch...

  16. 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....

  17. Comparative measurements of transpiration an canopy conductance in two mixed deciduous woodlands differing in structure and species composition

    DEFF Research Database (Denmark)

    Herbst, Mathias; Rosier, Paul T.W.; Morecroft, Michael D.;

    2008-01-01

    Transpiration of two heterogeneous broadleaved woodlands in southern England was monitored by the sap flux technique throughout the 2006 growing season. Grimsbury Wood, which had a leaf area index (LAI) of 3.9, was dominated by oak (Quercus robur L.) and birch (Betula pubescens L.) and had a cont...

  18. Indiana residents' perceptions of woodland management

    Science.gov (United States)

    Daniel J. Witter; Shannon M. Amberg; David J. Case; Phillip T. Seng

    2013-01-01

    A 2009 telephone survey of 1,402 Indiana adults was conducted to assess opinions regarding woodland management. Forty-eight percent said they were "very concerned" about the health and productivity of Indiana's woodlands, and 45 percent, "somewhat concerned." Almost half (47 percent) thought that the state's woodlands are held in about...

  19. 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...

  20. 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

  1. 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

  2. Farm woodlands for the future. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, P.J.; Brierley, E.D.R.; Morris, J. [eds.] [Cranfield University, Silsoe (United Kingdom). Institute of Water and Environment; Evans, J. [Imperial College, London (United Kingdom). T.H. Huxley School

    1999-07-01

    This book contains the papers presented at the conference on 'Farm Woodlands for the Future' held at Cranfield University on 8-10 September 1999. Topics covered include the socio-economic role of farm woodlands; the value of farm woodlands for shelter, biodiversity and landscape enhancement; the economic value of of farm woodlands; the value of agroforestry, poplar and short rotation coppice; and the promotion of farm woodlands. Of the eighteen papers published in this book, one is abstracted here.

  3. Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning

    Science.gov (United States)

    Asbjornsen, H.; Tomer, M.D.; Gomez-Cardenas, M.; Brudvig, L.A.; Greenan, C.M.; Schilling, K.

    2007-01-01

    Oak savannas, once common in the Midwest, are now isolated remnants within agricultural landscapes. Savanna remnants are frequently encroached by invasive trees to become woodlands. Thinning and prescribed burning can restore savanna structure, but the ecohydrological effects of managing these remnants are poorly understood. In this study, we measured sap flow (Js) to quantify transpiration in an Iowa bur oak (Quercus macrocarpa) savanna woodland encroached by elms (Ulmus americana), and in an adjacent restored savanna after thinning to remove elms, during summer 2004. Savanna oaks had greater mean daily Js (35.9 L dm-2 day-1) than woodland oaks (20.7 L dm-2 day-1) and elms (12.4 L dm-2 day-1). The response of Js to vapor pressure deficit (D) was unexpectedly weak, although oaks in both stands showed negative correlation between daily Js and D for D > 0.4 kPa. An earlier daily peak in Js in the elm trees showed a possible advantage for water uptake. As anticipated, the woodland's stand transpiration was greater (1.23 mm day-1) than the savanna's (0.35 mm day-1), yet the savanna achieved 30% of the woodland's transpiration with only 11% of its sapwood area. The difference in transpiration influenced water table depths, which were 2 m in the savanna and 6.5 m in the woodland. Regionally, row-crop agriculture has increased groundwater recharge and raised water tables, providing surplus water that perhaps facilitated elm encroachment. This has implications for restoration of savanna remnants. If achieving a savanna ecohydrology is an aim of restoration, then restoration strategies may require buffers, or targeting of large or hydrologically isolated remnants. ?? 2007.

  4. 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

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

    Science.gov (United States)

    Košulič, Ondřej; Michalko, Radek; Hula, Vladimír

    2016-01-01

    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-scale improvements

  6. Management Tools and Potential of Dry Miombo Woodland in Carbon Cycling

    DEFF Research Database (Denmark)

    Mwakalukwa, Ezekiel Edward

    Abstract Tools to support sustainable management of dry Miombo woodlands and precise assessment of carbon storage and sequestration potential are in most cases lacking in Tanzania. Accordingly, using Gangalamtumba Village Land Forest Reserve as a case study area located in Iringa region......, this thesis aims to develop management tools and generate information that will enhance our understanding of the actual and potential contribution of dry Miombo woodlands in carbon cycling. This is done through a detailed assessment of floristic composition, structure, species associations and through...... development of models for wood basic density, volume, biomass and growth. The overall research objective was thus to enhance the basis for good woodland management planning including exploring the extent to which dry Miombo woodlands in Tanzania store and sequester C from the atmosphere. Correct...

  7. 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

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

    Science.gov (United States)

    Bergerot, Benjamin; Merckx, Thomas; Van Dyck, Hans; Baguette, Michel

    2012-04-27

    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. 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. 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-benefit ratios of movements in fragmented landscapes.

  9. Pinyon-juniper woodlands [chapter 6

    Science.gov (United States)

    Gerald J. Gottfried; Thomas W. Swetnam; Craig D. Allen; Julio L. Betancourt; Alice L. Chung-MacCoubrey

    1995-01-01

    Pinyon-juniper woodlands are one of the largest ecosystems in the Southwest and in the Middle Rio Grande Basin (Fig. 1). The woodlands have been important to the region's inhabitants since prehistoric times for a variety of natural resources and amenities. The ecosystems have not been static; their distributions, stand characteristics, and site conditions have...

  10. 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.

  11. Examining the Resilience of Crop Production, Livestock Carrying Capacity, and Woodland Density in a Rural Zimbabwean Socio-Ecological System Using Agent-Based Models Representing Human Management Decisions

    Science.gov (United States)

    Eitzel Solera, M. V.; Neves, K.; Veski, A.; Solera, J.; Omoju, O. E.; Mawere Ndlovu, A.; Wilson, K.

    2016-12-01

    As climate change increases the pressures on arid ecosystems by changing timing and amount of rainfall, understanding the ways in which human management choices affect the resilience of these systems becomes key to their sustainability. On marginal farmland in Mazvihwa, Midlands Province, the historical carrying capacity of livestock has been consistently surprisingly high. We explore this phenomenon by building an agent-based model in NetLogo from a wealth of long-term data generated by the community-based participatory research team of The Muonde Trust, a Zimbabwean non-governmental organization. We combine the accumulated results of 35 years of indigenous and local knowledge with national datasets such as rainfall records. What factors keep the carrying capacity high? What management choices can maintain crops, livestock, and woodland at levels necessary for the community's survival? How do these choices affect long-term sustainability, and does increasing resilience at one scale reduce resilience at another scale? We use our agent-based model to explore the feedbacks between crops, livestock, and woodland and the impacts of various human choices as well as temporal and spatial ecological variation. By testing different scenarios, we disentangle the complex interactions between these components. We find that some factors out of the community's control can strongly affect the sustainability of the system through times of drought, and that supplementary feed may maintain livestock potentially at the expense of other resources. The challenges to resilience encountered by the farmers in Mazvihwa are not unique - many indigenous and rural people face drought and the legacies of colonialism, which contribute to lowered resilience to external challenges such as climate change, epidemics, and political instability. Using the agent-based model as a tool for synthesis and exploration initiates discussion about resilience-enhancing management choices for Mazvihwa's farmer-researchers.

  12. 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

  13. Sap flow measurements combining sap-flux density radial profiles with punctual sap-flux density measurements in oak trees (Quercus ilex and Quercus pyrenaica) - water-use implications in a water-limited savanna-

    Science.gov (United States)

    Reyes, J. Leonardo; Lubczynski1, Maciek W.

    2010-05-01

    measurements using the HFD-measured radial profiles. The standard TDP daily mean of sap-flux density was 95% higher than the 2cm equivalent of the HFD for Q. ilex and 70% higher for Q. pyrenaica. NTG-corrected TDP daily mean of sap-flux density was 34% higher than HFD for Q. ilex and 47% lower for Q. pyrenaica. Regarding sap flow measurements, the standard TDP sap flow was 81% higher than HFD sap flow for Q. ilex and 297% for Q. pyrenaica. The NTG-corrected TDP sap flow was 24% higher than HFD sap flow for Q. ilex and 23% for Q. pyrenaica. The radial correction, for TDP-NTG-corrected sap-flux density, produced sap-flow measurements in well agreement with HFD, just slightly lower (-3% Q.i. and -4% Q.p.). The TDP-HFD sap flow data acquired in dry season over the savanna type of sparsely distributed oak trees (Q. ilex & Q. pyrenaica) showed that the TDP method must be corrected for NTG and for radial variability of sap flux density in trees with sapwood thicker than 2 cm. If such corrections are not taken into consideration, the amount of accounted water used by the trees is prone to overestimation, especially for Quercus pyrenaica. The obtained results indicate also that the combination of HFD and TDP leads to an efficient and accurate operational sap flow measurement schema that is currently in the optimization stage.

  14. Pollen-limited reproduction in blue oak: Implications for wind pollination in fragmented populations

    Science.gov (United States)

    Knapp, E.E.; Goedde, M.A.; Rice, K.J.

    2001-01-01

    Human activities are fragmenting forests and woodlands worldwide, but the impact of reduced tree population densities on pollen transfer in wind-pollinated trees is poorly understood. In a 4-year study, we evaluated relationships among stand density, pollen availability, and seed production in a thinned and fragmented population of blue oak (Quercus douglasii). Geographic coordinates were established and flowering interval determined for 100 contiguous trees. The number of neighboring trees within 60 m that released pollen during each tree's flowering period was calculated and relationships with acorn production explored using multiple regression. We evaluated the effects of female flower production, average temperature, and relative humidity during the pollination period, and number of pollen-producing neighbors on individual trees' acorn production. All factors except temperature were significant in at least one of the years of our study, but the combination of factors influencing acorn production varied among years. In 1996, a year of large acorn crop size, acorn production was significantly positively associated with number of neighboring pollen producers and density of female flowers. In 1997, 1998, and 1999, many trees produced few or no acorns, and significant associations between number of pollen-producing neighbors and acorn production were only apparent among moderately to highly reproductive trees. Acorn production by these reproductive trees in 1997 was significantly positively associated with number of neighboring pollen producers and significantly negatively associated with average relative humidity during the pollination period. In 1998, no analysis was possible, because too few trees produced a moderate to large acorn crop. Only density of female flowers was significantly associated with acorn production of moderately to highly reproductive trees in 1999. The effect of spatial scale was also investigated by conducting analyses with pollen producers

  15. 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.

  16. Woodland Management Plan: Sherburne National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Four objectives have been established for the woodland management program for Sherburne NWR. These objectives are in compliance with and support the overall...

  17. Status of woodland caribou in western north America

    Directory of Open Access Journals (Sweden)

    E. Janet Edmonds

    1991-10-01

    Full Text Available A review of current population size and trends of woodland caribou (Rangifer tarandus caribou in seven jurisdictions in western North America shows a wide range of situations. A total maximum population estimate of woodland caribou west of the Ontario/Manitoba border is 61 090. Of 44 herds or populations described in this review: 14 are stable; two are stable to slightly decreasing; four are decreasing; four are increasing; and 22 are of unknown status. Caribou are classified as a threatened species in Alberta and as an endangered species in Washington/Idaho. The decline of caribou in North America following settlement (Bergerud, 1974 has continued along the southern edge of woodland caribou distribution. Direct loss of habitat to logging, mines and dams continued throughout the I960s, 1970s and 1980s. The secondary effects of these habitat changes, (i.e. increased roads leading to increased hunting and poaching, and increased early succession habitat leading to increased alternate prey/predator densities has led in some cases to the total loss or decreased size of local herds. Three ecotypes of woodland caribou are described and their relative distribution delineated. These ecotypes live under different environmental conditions and require different inventory and management approaches. Woodland caribou herds in northern B.C., Yukon and N.W.T. generally are of good numbers and viable (stable or increasing, and management primarily is directed at regulating human harvest and natural predation to prevent, herd declines. Land use activities such as logging or energy development are not extensive. Managers in southern caribou ranges stress the need for a better understanding of caribou population stability within mixed prey/predator regimes; how habitat changes (eg. through logging affect these regimes; and how to develop effective land use guidelines for resource extraction that can sustian caribou populations and maintain resource industries

  18. 75 FR 71463 - Woodland Mills Corporation Mill Spring, NC; Notice of Revised Determination on Reconsideration

    Science.gov (United States)

    2010-11-23

    ... Employment and Training Administration Woodland Mills Corporation Mill Spring, NC; Notice of Revised... of Woodland Mills Corporation, Mill Spring, North Carolina, to apply for Trade Adjustment Assistance... yarn produced by Woodland Mills Corporation, Mill Spring, North Carolina Woodland Mills...

  19. Survey of simple sequence repeats in woodland strawberry (Fragaria vesca).

    Science.gov (United States)

    Guan, L; Huang, J F; Feng, G Q; Wang, X W; Wang, Y; Chen, B Y; Qiao, Y S

    2013-07-30

    The use of simple sequence repeats (SSRs), or microsatellites, as genetic markers has become popular due to their abundance and variation in length among individuals. In this study, we investigated linkage groups (LGs) in the woodland strawberry (Fragaria vesca) and demonstrated variation in the abundances, densities, and relative densities of mononucleotide, dinucleotide, and trinucleotide repeats. Mononucleotide, dinucleotide, and trinucleotide repeats were more common than longer repeats in all LGs examined. Perfect SSRs were the predominant SSR type found and their abundance was extremely stable among LGs and chloroplasts. Abundances of mononucleotide, dinucleotide, and trinucleotide repeats were positively correlated with LG size, whereas those of tetranucleotide and hexanucleotide SSRs were not. Generally, in each LG, the abundance, relative abundance, relative density, and the proportion of each unique SSR all declined rapidly as the repeated unit increased. Furthermore, the lengths and frequencies of SSRs varied among different LGs.

  20. Developing monitoring techniques for the invasive goldspotted oak borer (Coleoptera: Buprestidae) in California.

    Science.gov (United States)

    Coleman, Tom W; Chen, Yigen; Graves, Andrew D; Hishinuma, Stacy M; Grulke, Nancy E; Flint, Mary Louise; Seybold, Steven J

    2014-06-01

    The goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), is an invasive species that has colonized oak woodlands in southern California. To better define its seasonal flight activity, assist with forest and integrated pest management activities, and define the current distribution in California, an effective monitoring technique for A. auroguttatus is necessary. We assessed the efficacy of two colors of flight-intercept prism traps, the placement of these traps at three heights, and several commercially available lures [Manuka oil, Phoebe oil, and a green leaf volatile, (3Z)-hexenol] for monitoring the flight of adult A. auroguttatus. Landing rates and the densities of D-shaped emergence holes of A. auroguttatus adults were assessed on the lower stems of coast live oak, Quercus agrifolia Née, of varying size and crown health classes. Purple flight-intercept prism traps placed at heights of 3 m and 4.5 m caught significantly more female A. auroguttatus than green prism traps. In one experiment, males also responded at a significantly higher level to purple than to green prism traps placed at 3 m height. The addition of commercially available lures significantly enhanced male, but not female, A. auroguttatus trap catch when compared with unbaited control traps. There were no differences among male flight responses to the three lures. A. auroguttatus landing rates and emergence hole densities were significantly greater on the largest-diameter trees (>76.2 cm diameter at breast height) and on trees with severe crown thinning or complete crown collapse. The annual increment in emergence hole densities was also significantly greater on trees with severe crown thinning or complete crown collapse. In three trapping studies over multiple years in southern California, the adult flight period began as early as mid-May, peaked in mid-June to early July, and ended in early- to mid-September. To demonstrate the efficacy of the detection method for A

  1. 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

  2. Analysing the effect of stand density and site conditions on structure and growth of oak species using Nelder trials along an environmental gradient: experimental design, evaluation methods, and results

    Institute of Scientific and Technical Information of China (English)

    Enno; Uhl; Peter; Biber; Matthias; Ulbricht; Michael; Heym; Tamás; Horváth; Ferenc; Lakatos; Janós; Gál; Leonhard; Steinacker; Giustino; Tonon; Maurizio; Ventura; Hans; Pretzsch

    2015-01-01

    Background: Most current approaches in forest science and practice require information about structure and growth of individual trees rather than- or in addition to- sum and mean values of growth and yield at forest stand level as provided by classic experimental designs. By inventing the wheel design, Nelder provided the possibility to turn to the individual tree as basic information unit. Such trials provide valuable insights into the dependency of growth on stand density at particular sites.Methods: Here, we present an extension of the original design and evaluation by Nelder.(i) We established Nelder wheels along an environmental gradient through Europe in atlantic climate in Belgium and Germany, Mediterranean climate in Italy, continental climate in Hungary as well as on high land climate in Mexico. Such disjunct Nelder wheels along an environmental gradient can be regarded and analysed as a two-factor design with the factors of site condition and stand density.(ii) We present an advanced statistical approach to evaluate density dependent growth dynamics of trees planted in form of the Nelder design, which considers spatio-temporal autocorrelation.(iii)We prove the usefulness of the methods in improving ecological theory concerning density related productivity,trade-offs between facilitation and competition, and allometric relations between size variables.Results: First evaluations based on remeasured Nelder wheels in oak(Quercus robur L.) show a size growth differentiation during the first observation period. In particular, height growth is accelerated under higher competition indicating facilitation effects. We detect furthermore a high variability in allometric relations.Conclusions: The proposed design, methods, and results are discussed regarding their impact on forest practice,model building, and ecological theory. We conclude that the extended Nelder approach is highly efficient in providing currently lacking individual tree level information.

  3. Analysing the effect of stand density and site conditions on structure and growth of oak species using Nelder trials along an environmental gradient: experimental design, evaluation methods, and results

    Directory of Open Access Journals (Sweden)

    Enno Uhl

    2015-05-01

    Full Text Available Background Most current approaches in forest science and practice require information about structure and growth of individual trees rather than - or in addition to - sum and mean values of growth and yield at forest stand level as provided by classic experimental designs. By inventing the wheel design, Nelder provided the possibility to turn to the individual tree as basic information unit. Such trials provide valuable insights into the dependency of growth on stand density at particular sites. Methods Here, we present an extension of the original design and evaluation by Nelder. (i We established Nelder wheels along an environmental gradient through Europe in atlantic climate in Belgium and Germany, Mediterranean climate in Italy, continental climate in Hungary as well as on high land climate in Mexico. Such disjunct Nelder wheels along an environmental gradient can be regarded and analysed as a two-factor design with the factors of site condition and stand density. (ii We present an advanced statistical approach to evaluate density dependent growth dynamics of trees planted in form of the Nelder design, which considers spatio-temporal autocorrelation. (iii We prove the usefulness of the methods in improving ecological theory concerning density related productivity, trade-offs between facilitation and competition, and allometric relations between size variables. Results First evaluations based on remeasured Nelder wheels in oak (Quercus roburL. show a size growth differentiation during the first observation period. In particular, height growth is accelerated under higher competition indicating facilitation effects. We detect furthermore a high variability in allometric relations. Conclusions The proposed design, methods, and results are discussed regarding their impact on forest practice, model building, and ecological theory. We conclude that the extended Nelder approach is highly efficient in providing currently lacking individual tree level

  4. The Study of Woodland Use Efficiency from the Perspective of Forest Resources Change

    Institute of Scientific and Technical Information of China (English)

    Shaozhou; ZHOU; Min; LIU

    2014-01-01

    From the perspective of forest resources change,this article uses comparative analysis and panel data regression to study the woodland use efficiency from forest resources quantity and quality change.The results show that although the forest coverage and forest stock volume per hectare show an overall upward trend,there are different change laws between the two;there are also differences in the influencing factors between forest coverage and forest stock volume per hectare( population density,rainfall and project having significant effect on forest coverage;population density,economic density and institution having significant effect on forest stock per hectare).Finally the recommendations are put forth for improving the woodland resources use efficiency:it is necessary to improve both the forest quantity and forest quality,focus on demand and supply,and pay equal attention to project promotion and property rights system reform.

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

    Science.gov (United States)

    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

  6. Ridgefield - Himalayan Blackberry Removal/Woodland Regeneration

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project would expand the control, restoration, and monitoring efforts to replace stands of Himalayan blackberry and reed canarygrass with Oregon oak and Oregon...

  7. Seedling diversity and spatially related regenaration dynamics in holly woodlands and surrounding habitats

    Directory of Open Access Journals (Sweden)

    S. Arrieta

    2001-06-01

    Full Text Available Spatial patterns of seedling distribution and diversity were analysed in small fragments of holly Ilex aquifolium L. woodlands and in their surrounding areas. Two sampling locations with similar structure were selected for this study: Oncala and Robregordo. They consist of nearly monospecific Ilex stands surrounded by grasslands with high scrub abundance.

    The seedling appearance of woody species was quantified from March to November 1998. Sampled areas were: 1 closed holly canopy; 2 open holly canopy or small forest gaps; 3 holly woodland edge; 4 surrounding grassland; 5 under isolated fleshy-fruited shrubs scattered over the grassland; 6 under dry-fruited shrubs and 7 the closest forest to the holly woodland. Additionally, a pine forest at a distance of 20 km from Oncala was sampled. In every area ten permanent 50 × 50 cm quadrats were fixed for monthly seedling control.

    The highest germination density occurs under the holly woodland, especially in closed canopy areas. Nevertheless, these closed woodlands neither maintain a great quantity of surviving seedlings nor a high diversity. Seedling density is considerable in canopy gaps, shrubs and forest edge, and these habitats have greater diversity values than understorey habitats. Fleshy-fruited shrubs maintain higher seedling densities and diversity than dry-fruited shrubs. Woody seedlings are rare over the grassland. The three non-holly forests studied have very similar seedling densities and diversity values, higher than those under closed-canopy holly.

    Regional differences are important for the numbers of seedlings surviving from previous years, which are scareer in Robregordo. However, little difference is observed in spatial patterns of seedling diversity between the two locations.

    We discuss a number of processes affecting seed rain density and differential mortality rates that could account for these spatial patterns, namely competition

  8. Bur oak savanna

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of research and activities related to bur oak savanna on Neal Smith National Wildlife Refuge between 1992 and 2006. Titles of studies summarized in...

  9. Poison ivy - oak - sumac

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002886.htm Poison ivy - oak - sumac To use the sharing features ... the plant, if known Amount swallowed (if swallowed) Poison Control Your local poison center can be reached ...

  10. 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.

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

    Science.gov (United States)

    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

  12. Variation in the radial patterns of sap flux density in pubescent oak (Quercus pubescens) and its implications for tree and stand transpiration measurements.

    Science.gov (United States)

    Poyatos, Rafael; Cermák, Jan; Llorens, Pilar

    2007-04-01

    Radial variation in sap flux density across the sapwood was assessed by the heat field deformation method in several trees of Quercus pubescens Wild., a ring-porous species. Sapwood depths were delimited by identifying the point of zero flow in radial patterns of sap flow, yielding tree sapwood areas that were 1.5-2 times larger than assumed based on visual examinations of wood cores. The patterns of sap flow varied both among trees and diurnally. Rates of sap flow were higher close to the cambium, although there was a significant contribution from the inner sapwood, which was greater (up to 60% of total flow) during the early morning and late in the day. Accordingly, the normalized difference between outer and inner sapwood flow was stable during the middle of the day, but showed a general decline in the afternoon. The distribution of sap flux density across the sapwood allowed us to derive correction coefficients for single-point heat dissipation sap flow measurements. We used daytime-averaged coefficients that depended on the particular shape of the radial profile and ranged between 0.45 and 1.28. Stand transpiration calculated using the new method of estimating sapwood areas and the radial correction coefficients was similar to (Year 2003), or about 25% higher than (Year 2004), previous uncorrected values, and was 20-30% of reference evapotranspiration. We demonstrated how inaccuracies in determining sapwood depths and mean sap flux density across the sapwood of ring-porous species could affect tree and stand transpiration estimates.

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

    Directory of Open Access Journals (Sweden)

    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

  14. The West Central Alberta Woodland Caribou Landscape Plan: Using a Modeling Approach to Develop Alternative Scenarios

    Directory of Open Access Journals (Sweden)

    Anne Hubbs

    2011-09-01

    Full Text Available Woodland caribou (Rangifer tarandus are classified as threatened in Alberta. In support of Canada's Species at Risk Act, a Recovery Plan for Woodland Caribou in Alberta was completed in 2004 which required local implementation plans to be completed within 5 areas of the province. The West Central Alberta Caribou Landscape Plan (WCCLP is the first of these to be initiated and it addresses the recovery strategies for 4 herds. Two aspatial computer models built on the STELLA© modelling platform (ISee Systems, 2007 were used to assist the planning team in evaluating cumulative effects and alternative scenarios for caribou conservation. The ALCES© (Forem Technologies 2008 modelling tool was used to forecast potential changes in the west central Alberta landscape over time. Yearly landscape condition outputs from ALCES© were then exported into a caribou-specific population model, REMUS© (Weclaw, 2004, that was used to project potential population responses by woodland caribou, other primary prey species [moose (Alces alces, elk (Cervus elaphus and deer (Odocoileus sp.] and wolves (Canis lupus (Weclaw & Hudson, 2004. Simulated habitat management strategies that resulted in the highest likelihood of caribou recovery included the maintenance of a high proportion of old forest, the aggregation of industrial footprints and the reclamation of historic seismic lines (although the latter took decades to provide real dividends. Sharing of industrial roads, protection of fragments of old-growth, and expanding an already aggressive fire control strategy in Alberta had little additional effect on caribou recovery. Simulated population management strategies that were successful all involved decades of intensive wolf control, either directly or indirectly through intensive primary prey control (with the exception of woodland caribou until old-growth forests recovered to densities that provided caribou habitat and decreased alternate prey of wolves. Although

  15. Landscape dynamics in Mediterranean oak forests under global change: understanding the role of anthropogenic and environmental drivers across forest types.

    Science.gov (United States)

    Acácio, Vanda; Dias, Filipe S; Catry, Filipe X; Rocha, Marta; Moreira, Francisco

    2017-03-01

    The Mediterranean region is projected to be extremely vulnerable to global change, which will affect the distribution of typical forest types such as native oak forests. However, our understanding of Mediterranean oak forest responses to future conditions is still very limited by the lack of knowledge on oak forest dynamics and species-specific responses to multiple drivers. We compared the long-term (1966-2006) forest persistence and land cover change among evergreen (cork oak and holm oak) and deciduous oak forests and evaluated the importance of anthropogenic and environmental drivers on observed changes for Portugal. We used National Forest Inventories to quantify the changes in oak forests and explored the drivers of change using multinomial logistic regression analysis and an information theoretical approach. We found distinct trends among oak forest types, reflecting the differences in oak economic value, protection status and management schemes: cork oak forests were the most persistent (62%), changing mostly to pines and eucalypt; holm oak forests were less persistent (53.2%), changing mostly to agriculture; and deciduous oak forests were the least persistent (45.7%), changing mostly to shrublands. Drivers of change had distinct importance across oak forest types, but drivers from anthropogenic origin (wildfires, population density, and land accessibility) were always among the most important. Climatic extremes were also important predictors of oak forest changes, namely extreme temperatures for evergreen oak forests and deficit of precipitation for deciduous oak forests. Our results indicate that under increasing human pressure and forecasted climate change, evergreen oak forests will continue declining and deciduous oak forests will be replaced by forests dominated by more xeric species. In the long run, multiple disturbances may change competitive dominance from oak forests to pyrophytic shrublands. A better understanding of forest dynamics and the

  16. Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for mediterranean evergreen woodlands

    Science.gov (United States)

    Pinho, P.; Theobald, M. R.; Dias, T.; Tang, Y. S.; Cruz, C.; Martins-Loução, M. A.; Máguas, C.; Sutton, M.; Branquinho, C.

    2011-11-01

    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 have been established, such as critical loads (deposition fluxes) and levels (concentrations). For Mediterranean ecosystems, few studies have been carried out to assess these parameters. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for Mediterranean evergreen woodlands. For that we have considered changes in epiphytic lichen communities, which have been shown to be one of the most sensitive to excessive N. 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 under Mediterranean climate, in evergreen cork-oak woodlands, by sampling lichen functional diversity and annual atmospheric ammonia concentrations and modelling N deposition downwind from a reduced N source (a cattle barn). By modelling the highly significant relationship between lichen functional groups and N deposition, the critical load was estimated to be below 26 kg (N) ha-1 yr-1, which is within the upper range established for other semi-natural ecosystems. By modelling the highly significant relationship of lichen functional groups with annual atmospheric ammonia concentration, the critical level was estimated to be below 1.9 μg m-3, in agreement with recent studies for other ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should be taken into account in policies that aim at protecting Mediterranean woodlands from the initial effects of excessive N.

  17. Critical loads of nitrogen deposition and critical levels of atmospheric ammonia for mediterranean evergreen woodlands

    Directory of Open Access Journals (Sweden)

    P. Pinho

    2011-11-01

    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 have been established, such as critical loads (deposition fluxes and levels (concentrations. For Mediterranean ecosystems, few studies have been carried out to assess these parameters. Our objective was therefore to determine the critical loads of N deposition and long-term critical levels of atmospheric ammonia for Mediterranean evergreen woodlands. For that we have considered changes in epiphytic lichen communities, which have been shown to be one of the most sensitive to excessive N. 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 under Mediterranean climate, in evergreen cork-oak woodlands, by sampling lichen functional diversity and annual atmospheric ammonia concentrations and modelling N deposition downwind from a reduced N source (a cattle barn. By modelling the highly significant relationship between lichen functional groups and N deposition, the critical load was estimated to be below 26 kg (N ha−1 yr−1, which is within the upper range established for other semi-natural ecosystems. By modelling the highly significant relationship of lichen functional groups with annual atmospheric ammonia concentration, the critical level was estimated to be below 1.9 μg m−3, in agreement with recent studies for other ecosystems. Taking into account the high sensitivity of lichen communities to excessive N, these values should be taken into account in policies that aim at protecting Mediterranean woodlands from the initial effects of excessive N.

  18. Woodland type and spatial distribution of nymphal Ixodes scapularis (Acari: Ixodidae)

    Science.gov (United States)

    Ginsberg, Howard S.; Zhioua, Elyes; Mitra, Shaibal; Fischer, Jason L.; Buckley, P.A.; Verret, Frank; Underwood, H. Brian; Buckley, Francine G.

    2004-01-01

    Spatial distribution patterns of black-legged ticks, Ixodes scapularis, in deciduous and coniferous woodlands were studied by sampling ticks in different woodland types and at sites from which deer had been excluded and by quantifying movement patterns of tick host animals (mammals and birds) at the Lighthouse Tract, Fire Island, NY, from 1994 to 2000. Densities of nymphal ticks were greater in deciduous than coniferous woods in 3 of 7 yr. Only engorged ticks survived the winter, and overwintering survival of engorged larvae in experimental enclosures did not differ between deciduous and coniferous woods. Nymphs were not always most abundant in the same forest type as they had been as larvae, and the habitat shift between life stages differed in direction in different years. Therefore, forest type by itself did not account for tick distribution patterns. Nymphal densities were lower where deer had been excluded compared with areas with deer present for 3 yr after exclusion, suggesting that movement patterns of vertebrate hosts influenced tick distribution, but nymphal densities increased dramatically in one of the enclosures in the fourth year. Therefore, movements of ticks on animal hosts apparently contribute substantially to tick spatial distribution among woodland types, but the factor(s) that determine spatial distribution of nymphal I. scapularis shift from year to year.

  19. Soil Black Carbon Loss and Sediment Black Carbon Accumulation in a Central Texas Woodland

    Science.gov (United States)

    Schieve, E. A.; Hockaday, W. C.; White, J. D.

    2016-12-01

    The Balcones Canyonlands National Wildlife Refuge is located along the eastern edge of the Edwards Plateau in Texas, and was established in 1992 for the purpose of conserving habitat for two endangered bird species. The landscape is composed of hilly, mesa-valley terrain, which is mostly covered by grasslands and woodlands dominated by juniper with intermingling of various oak species. Based on historical photo analysis and tree fire scar dendrochronology, the area has experienced major land use changes over the last century due to wildfire, logging, and drought affecting soil stability and woodland species composition. A previous study on soil black carbon showed that site-specific soil erosion potential and time since last fire may act as controls on soil black carbon concentrations. However, the black carbon transport flux, depositional fate, or the magnitude of soil erosion effects upon the black carbon budget are unconstrained at the watershed scale. To address this, we sampled the sediments accumulating in small ponds constructed during the 1950's for livestock watering. We are quantifying black carbon in sediments using solid-state 13C nuclear magnetic resonance spectroscopy. Preliminary data suggest that the pond sediments are a black carbon sink. Black carbon comprises 15 % - 25 %, of the sedimentary organic carbon, as substantial enrichment relative to soils within the watershed. We will present an early assessment of the black carbon erosion and sediment accumulation rates in first- and second-order watersheds.

  20. Conversion of an oak seed orchard to oak silvopasture

    Science.gov (United States)

    K. Connor; L. Dimov; R. Barlow; M. Smith; E. Kirkland

    2013-01-01

    The potential of hardwood silvopasture has yet to be realized in the Southeastern United States. The decommissioning of the Stauffer Nursery, Opelika, AL, provided the opportunity to intensively research hardwood silvopasture using various oak species. Average crown diameter ranged from 5.9 feet in white oak (Quercus alba) to 10.7 feet in Nuttall oak...

  1. Diurnal and Seasonal Changes in Stem Radius Increment and Sap Flow Density Indicate Different Responses of Two Co-existing Oak Species to Drought Stress

    Directory of Open Access Journals (Sweden)

    MÉSZÁROS, Ilona

    2011-01-01

    Full Text Available Using continuous monitoring of stem radius combined with sap flow measurements weassessed the effects of environmental conditions on tree radial growth and water status of two coexistingoak species (Quercus petraea and Quercus cerris at high resolution time in growingseasons of 2008 and 2009. The forest (95–100 yr is situated in a xeric site in the transition zonebetween forested and forest-steppe regions in north-eastern Hungary, Bükk mountains (47o90’N,20o46’E, elevation 320–340 m a.s.l.. Weather conditions in the growing season of 2008 (totalrainfall 354 mm, mean daily temperature 17.0 oC was less extreme than in 2009 (total rainfall299 mm, temperature 17.9 oC. Rainfall strongly determined the course of radial growth incrementin trees. Radial growth of trees was limited in 2009 due to the drought in spring. The maximumradial increment of both species was achieved three weeks earlier (4th week of June than in 2008(4th week of July. We used dendrometer monitoring data for estimation of stem (tree waterdeficit (W by measuring water-related changes in stem radius (Zweifel et al. 2005. Themagnitude of tree water deficit variation (W was always smaller in Q. cerris than in Q. petraea.In contrast, Quercus cerris always exhibited larger daytime averages and maxima of sap flowdensity. In August of 2009 when drought became severe there were larger increases in tree waterdeficit (W (50–55 % in both species compared to July as it could be expected from the extentof decreases in sap flow density (24–28%. Our data suggested that due to the low SWC thetranspiration was supported mainly from the inner water storage of trees during prolonged droughtwhich resulted in high stem water deficit (W.

  2. RESTORATION OF QUAKING ASPEN WOODLANDS INVADED BY WESTERN JUNIPER

    Science.gov (United States)

    Quaking aspen woodlands are important plant communities in the interior mountains of the western United States, providing essential habitat for many wildlife species and contain a high diversity of understory plants. Western juniper woodlands are rapidly replacing lower elevation (<6800 ft) quaking...

  3. Poison Ivy/Oak/Sumac

    Science.gov (United States)

    ... Your 1- to 2-Year-Old First Aid: Poison Ivy/Oak/Sumac KidsHealth > For Parents > First Aid: Poison Ivy/Oak/Sumac Print A A A The oil in poison ivy /oak/sumac plants (called urushiol ) can cause ...

  4. Assessment of soil erosion under woodlands using USLE in China

    Institute of Scientific and Technical Information of China (English)

    Changshun ZHANG; Gaodi XIE; Chunlan LIU; Chunxia LU

    2011-01-01

    Universal Soil Loss Equation (USLE),originally developed by the USDA for agricultural lands and then used throughout the world,was applied in mountainous forest terrain in China.The woodland area was divide into 100 m × 100 m grid cells.The ArcInfo 9.2 GIS software provided spatial input data was used to predict the spatial distribution of the average annual soilloss on grid basis.The average rainfall erositivityfactor (R) for national woodlands was found to be 21-highest for Chinese woodland.Most of the slope lengthfactors (LS) were less than 5 for the national woodland.The highest and lowest values of cover and managementfactor (C) were found out to be 0.0068 and 0.2550respectively for coniferous woodland and orchard woodland.The value of conservation factor (P) was assigned to be 1 for Chinese woodlands because of scarcity of conversation practice data at the national scale.The average annual soil loss of the national woodland areas area was found out to be under slight erosion class,whereas it only resulted in about 41.97% of soil loss under woodland area,and 58.03% of soil loss occurred under Therefore,those zones need immediate attention from soil conservation point of view.The results here are consistent with many domestic and oversea previous researches under mountainous forests or hilly catchments,thus we showed that the USLE can be applied to estimations of soil erosion for Chinese woodlands at the national scale.

  5. Management of oak forests

    DEFF Research Database (Denmark)

    Löf, Magnus; Brunet, Jörg; Filyushkina, Anna

    2016-01-01

    uses. Management for the production of high-value timber species like oaks and management to conserve biodiversity, or for cultural services can be in conflict with each other. This study evaluates the capacity of three contrasting management regimes to provide societies with economic revenue from...

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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.

  8. Optimization of dry - season sap flow measurements in an oak semi - arid open woodland in Spain

    NARCIS (Netherlands)

    Reyes-Acosta, J.L.; Lubczynski, M.

    2014-01-01

    In sap flow studies, there is no method complying with high efficiency and versatility of sap flow measurements. To improve that, we propose combining two methods: (1) thermal dissipation probe (TDP) known to be efficient and cost effective and (2) heat field deformation (HFD) known to be versatile.

  9. Turbidity and total suspended solid concentration dynamics in streamflow from California oak woodland watersheds

    Science.gov (United States)

    David J. Lewis; Kenneth W. Tate; Randy A. Dahlgren; Jacob Newell

    2002-01-01

    Resource agencies, private landowners, and citizen monitoring programs utilize turbidity (water clarity) measurements as a water quality indicator for total suspended solids (TSS – mass of solids per unit volume) and other constituents in streams and rivers. The dynamics and relationships between turbidity and TSS are functions of watershed-specific factors and...

  10. The role of forest certification for the conservation of biodiversity and sustainability of cork oak woodlands

    OpenAIRE

    Dias, Filipe Eduardo Parreiras Silva

    2015-01-01

    Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL Sustainable forest management is crucial for the conservation of biodiversity and ecosystem services. Forest certification (FC) is a market-based conservation tool based on third-party auditing of compliance with environmental and socio-economic sustainable management standards. Forest Stewardship Council (FSC) certification is a major certification scheme covering 183 million hectares of fo...

  11. Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover

    Science.gov (United States)

    Grundel, Ralph; Pavlovic, Noel B.; Sulzman, Christina L.

    1998-01-01

    The Karner blue butterfly Lycaeides melissa samuelis is an endangered species residing in the Great Lakes and northeastern regions of the United States. Increased canopy cover is a major factor implicated in the decline of the Karner blue at many locales. Therefore, we examined how the butterfly's behavior varied with canopy cover. Adult males at Indiana Dunes National Lakeshore used habitat under canopy openings for nearly 90% of their activities; females used openings and shaded areas more equally. The frequency of oviposition on the sole host plant, wild lupine Lupinus perennis, was highest under 30–60% canopy cover even though lupine was more abundant in more open areas. Larvae fed preferentially on larger lupine plants and on lupines in denser patches. However, lupines were generally larger in the shade. Therefore, shade-related trade-offs existed between lupine abundance and distribution of larval feeding and oviposition. Also, heterogeneity of shading by sub-canopy woody vegetation was greater at oviposition sites than at sites where lupine did not grow. Given the importance of shade heterogeneity, a mixture of canopy openings and shade, on a scale similar to daily adult movement range, should be beneficial for this butterfly.

  12. The Effect of Anthropogenic Disturbance in the Ecohydrology of Pinyon Juniper Woodlands with Soil Biocrust

    Science.gov (United States)

    Lebron, I.; Chandler, D. G.; Robinson, D. A.; Belnap, J.; Madsen, M.

    2005-12-01

    The canopy and intercanopy in pinyon-juniper woodlands are intrinsically related and constitute an ecosystem of great importance in the arid lands in the United States. The integrity of this ecosystem is continually challenged by anthropogenic disturbances as oil exploration and recreation activities in these environments. An important feature in the intercanopy of pinyon juniper drylands is the soil biological crust or biocrust. Biocrust is important to the nutrient cycles and hydrology and sediment production of this system. To quantify the effect of disturbances in the soil physical properties in the interspace of a pinion-juniper woodland we measured soil bulk density, water content, and hydraulic conductivity in undisturbed and disturbed areas of sandy soil. The disturbance had minimal impact on the bulk soil properties in the interspace soils. We also analyzed chlorophyll and other pigments related with bacterial activity in top 4mm of the soil and found chlorophyll activity to be almost zero in the disturbed areas while the undisturbed ones showed several orders of magnitude higher concentrations. Subsequent analysis of the soil surface properties indicates that a drastic change in the surface roughness and structure at the surface due to disturbances can alter the microenvironment characteristics critical for the bacterial survival. Since cyanobacteria colonization is the first step in the formation of biocrust, we conclude that surface properties are critical for the preservation and establishment of biocrust in the intercanopy space of the pinyon-juniper woodlands ecosystems.

  13. 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.

  14. 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)....

  15. The genome of woodland strawberry (Fragaria vesca).

    Science.gov (United States)

    Shulaev, Vladimir; Sargent, Daniel J; Crowhurst, Ross N; Mockler, Todd C; Folkerts, Otto; Delcher, Arthur L; Jaiswal, Pankaj; Mockaitis, Keithanne; Liston, Aaron; Mane, Shrinivasrao P; Burns, Paul; Davis, Thomas M; Slovin, Janet P; Bassil, Nahla; Hellens, Roger P; Evans, Clive; Harkins, Tim; Kodira, Chinnappa; Desany, Brian; Crasta, Oswald R; Jensen, Roderick V; Allan, Andrew C; Michael, Todd P; Setubal, Joao Carlos; Celton, Jean-Marc; Rees, D Jasper G; Williams, Kelly P; Holt, Sarah H; Ruiz Rojas, Juan Jairo; Chatterjee, Mithu; Liu, Bo; Silva, Herman; Meisel, Lee; Adato, Avital; Filichkin, Sergei A; Troggio, Michela; Viola, Roberto; Ashman, Tia-Lynn; Wang, Hao; Dharmawardhana, Palitha; Elser, Justin; Raja, Rajani; Priest, Henry D; Bryant, Douglas W; Fox, Samuel E; Givan, Scott A; Wilhelm, Larry J; Naithani, Sushma; Christoffels, Alan; Salama, David Y; Carter, Jade; Lopez Girona, Elena; Zdepski, Anna; Wang, Wenqin; Kerstetter, Randall A; Schwab, Wilfried; Korban, Schuyler S; Davik, Jahn; Monfort, Amparo; Denoyes-Rothan, Beatrice; Arus, Pere; Mittler, Ron; Flinn, Barry; Aharoni, Asaph; Bennetzen, Jeffrey L; Salzberg, Steven L; Dickerman, Allan W; Velasco, Riccardo; Borodovsky, Mark; Veilleux, Richard E; Folta, Kevin M

    2011-02-01

    The woodland strawberry, Fragaria vesca (2n = 2x = 14), is a versatile experimental plant system. This diminutive herbaceous perennial has a small genome (240 Mb), is amenable to genetic transformation and shares substantial sequence identity with the cultivated strawberry (Fragaria × ananassa) and other economically important rosaceous plants. Here we report the draft F. vesca genome, which was sequenced to ×39 coverage using second-generation technology, assembled de novo and then anchored to the genetic linkage map into seven pseudochromosomes. This diploid strawberry sequence lacks the large genome duplications seen in other rosids. Gene prediction modeling identified 34,809 genes, with most being supported by transcriptome mapping. Genes critical to valuable horticultural traits including flavor, nutritional value and flowering time were identified. Macrosyntenic relationships between Fragaria and Prunus predict a hypothetical ancestral Rosaceae genome that had nine chromosomes. New phylogenetic analysis of 154 protein-coding genes suggests that assignment of Populus to Malvidae, rather than Fabidae, is warranted.

  16. Monitoring of recharge water quality under woodland

    Science.gov (United States)

    Krajenbrink, G. J. W.; Ronen, D.; Van Duijvenbooden, W.; Magaritz, M.; Wever, D.

    1988-03-01

    The study compares the quality of groundwater in the water table zone and soil moisture below the root zone, under woodland, with the quality of the regional precipitation. The water quality under forest shows evidence of the effect of atmospheric deposition of acidic components (e.g. SO 2) and ammonia volatilized from land and feed lots. Detailed chemical profiles of the upper meter of groundwater under different plots of forest, at varying distances from cultivated land, were obtained with a multilayer sampler, using the dialysis-cell method. Porous ceramic cups and a vacuum method were used to obtain soil moisture samples at 1.20 m depth under various types of trees, an open spot and arable land, for the period of a year. The investigation took place in the recharge area of a pumping station with mainly mixed forest, downwind of a vast agricultural area with high ammonia volatilization and underlain by an ice-deformed aquifer. Very high NO -3 concentrations were observed in soil moisture and groundwater (up to 21 mg Nl -1) under coniferous forest, especially in the border zone. This raises the question of the dilution capacity of recharge water under woodland in relation to the polluted groundwater under farming land. The buffering capacity of the unsaturated zone varies substantially and locally a low pH (4.5) was observed in groundwater. The large variability of leachate composition on different scales under a forest and the lesser but still significant concentration differences in the groundwater prove the importance of a monitoring system for the actual solute flux into the groundwater.

  17. 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....

  18. Assessment of soil erosion under woodlands using USLE in China

    Science.gov (United States)

    Zhang, Changshun; Xie, Gaodi; Liu, Chunlan; Lu, Chunxia

    2011-06-01

    Universal Soil Loss Equation (USLE), originally developed by the USDA for agricultural lands and then used throughout the world, was applied in mountainous forest terrain in China. The woodland area was divide into 100 m × 100 m grid cells. The ArcInfo 9.2 GIS software provided spatial input data was used to predict the spatial distribution of the average annual soil loss on grid basis. The average rainfall erositivity factor ( R) for national woodlands was found to be 21-1798 MJ·mm·ha-1·h-1·a-1. The soil erodibility factor ( K) with a magnitude of 0.043 t·ha·h· ha-1·MJ-1·mm-1 is the highest for Chinese woodland. Most of the slope length factors ( LS) were less than 5 for the national woodland. The highest and lowest values of cover and management factor ( C) were found out to be 0.0068 and 0.2550 respectively for coniferous woodland and orchard woodland. The value of conservation factor ( P) was assigned to be 1 for Chinese woodlands because of scarcity of conversation practice data at the national scale. The average annual soil loss of the national woodland areas was 3.82 t·km-2·a-1. About 99.89% of Chinese woodland area was found out to be under slight erosion class, whereas it only resulted in about 41.97% of soil loss under woodland area, and 58.03% of soil loss occurred under high erosion potential zone, namely more than 5 t·ha-1·a-1. Therefore, those zones need immediate attention from soil conservation point of view. The results here are consistent with many domestic and oversea previous researches under mountainous forests or hilly catchments, thus we showed that the USLE can be applied to estimations of soil erosion for Chinese woodlands at the national scale.

  19. 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

    Directory of Open Access Journals (Sweden)

    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.

  20. Challenging the Woodfuel Crisis in West African Woodlands

    DEFF Research Database (Denmark)

    Hansfort, Sofie Louise; Mertz, Ole

    2011-01-01

    —have been produced by the government of Mali to prove the impacts of woodfuel consumption in Bamako on surrounding woodlands. This study evaluates the methodology and data used to describe this woodfuel crisis through a comparison with regional and historical data. The results of the energy gap analyses...... of West African woodlands and urban consumption are needed to avoid misinterpretations of the impacts of woodfuel harvesting on woody resources....

  1. 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

  2. A long-term experimental site in temperate oak-pine forest

    OpenAIRE

    Korboulewsky, N.; Balandier, P.; Ballon, P; Boscardin, Y.; Dauffy Richard, E.; Dumas, Y.; Ginisty, C.; Gosselin, M.; Hamard, J.P.; Laurent, L.; Marell, A.; Menuet, C.; Ndiaye, A.; Novara, E.; Pérot, T.

    2015-01-01

    The objective is to study the cross effects of: - stand composition (pure oak, pure pine, mixed pine-oak) and - stand density (number of trees/ha) combined with - presence of wild ungulates (roe deer, wild boar, red deer), on the ecosystem functioning such as tree productivity, resource use and allocation (including water and nutrients), biodiversity and understory vegetation dynamics including regeneration.

  3. The genome of woodland strawberry (Fragaria vesca)

    Science.gov (United States)

    Shulaev, Vladimir; Sargent, Daniel J; Crowhurst, Ross N; Mockler, Todd C; Folkerts, Otto; Delcher, Arthur L; Jaiswal, Pankaj; Mockaitis, Keithanne; Liston, Aaron; Mane, Shrinivasrao P; Burns, Paul; Davis, Thomas M; Slovin, Janet P; Bassil, Nahla; Hellens, Roger P; Evans, Clive; Harkins, Tim; Kodira, Chinnappa; Desany, Brian; Crasta, Oswald R; Jensen, Roderick V; Allan, Andrew C; Michael, Todd P; Setubal, Joao Carlos; Celton, Jean-Marc; Rees, D Jasper G; Williams, Kelly P; Holt, Sarah H; Ruiz Rojas, Juan Jairo; Chatterjee, Mithu; Liu, Bo; Silva, Herman; Meisel, Lee; Adato, Avital; Filichkin, Sergei A; Troggio, Michela; Viola, Roberto; Ashman, Tia-Lynn; Wang, Hao; Dharmawardhana, Palitha; Elser, Justin; Raja, Rajani; Priest, Henry D; Bryant, Douglas W; Fox, Samuel E; Givan, Scott A; Wilhelm, Larry J; Naithani, Sushma; Christoffels, Alan; Salama, David Y; Carter, Jade; Girona, Elena Lopez; Zdepski, Anna; Wang, Wenqin; Kerstetter, Randall A; Schwab, Wilfried; Korban, Schuyler S; Davik, Jahn; Monfort, Amparo; Denoyes-Rothan, Beatrice; Arus, Pere; Mittler, Ron; Flinn, Barry; Aharoni, Asaph; Bennetzen, Jeffrey L; Salzberg, Steven L; Dickerman, Allan W; Velasco, Riccardo; Borodovsky, Mark; Veilleux, Richard E; Folta, Kevin M

    2012-01-01

    The woodland strawberry, Fragaria vesca (2n = 2x = 14), is a versatile experimental plant system. This diminutive herbaceous perennial has a small genome (240 Mb), is amenable to genetic transformation and shares substantial sequence identity with the cultivated strawberry (Fragaria × ananassa) and other economically important rosaceous plants. Here we report the draft F. vesca genome, which was sequenced to ×39 coverage using second-generation technology, assembled de novo and then anchored to the genetic linkage map into seven pseudochromosomes. This diploid strawberry sequence lacks the large genome duplications seen in other rosids. Gene prediction modeling identified 34,809 genes, with most being supported by transcriptome mapping. Genes critical to valuable horticultural traits including flavor, nutritional value and flowering time were identified. Macrosyntenic relationships between Fragaria and Prunus predict a hypothetical ancestral Rosaceae genome that had nine chromosomes. New phylogenetic analysis of 154 protein-coding genes suggests that assignment of Populus to Malvidae, rather than Fabidae, is warranted. PMID:21186353

  4. 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.

  5. 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.

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

    Science.gov (United States)

    Pinho, P.; Theobald, M. R.; Dias, T.; Tang, Y. S.; Cruz, C.; Martins-Loução, M. A.; Máguas, C.; Sutton, M.; Branquinho, C.

    2012-03-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Tree Crown Delineation on Vhr Aerial Imagery with Svm Classification Technique Optimized by Taguchi Method: a Case Study in Zagros Woodlands

    Science.gov (United States)

    Erfanifard, Y.; Behnia, N.; Moosavi, V.

    2013-09-01

    The Support Vector Machine (SVM) is a theoretically superior machine learning methodology with great results in classification of remotely sensed datasets. Determination of optimal parameters applied in SVM is still vague to some scientists. In this research, it is suggested to use the Taguchi method to optimize these parameters. The objective of this study was to detect tree crowns on very high resolution (VHR) aerial imagery in Zagros woodlands by SVM optimized by Taguchi method. A 30 ha plot of Persian oak (Quercus persica) coppice trees was selected in Zagros woodlands, Iran. The VHR aerial imagery of the plot with 0.06 m spatial resolution was obtained from National Geographic Organization (NGO), Iran, to extract the crowns of Persian oak trees in this study. The SVM parameters were optimized by Taguchi method and thereafter, the imagery was classified by the SVM with optimal parameters. The results showed that the Taguchi method is a very useful approach to optimize the combination of parameters of SVM. It was also concluded that the SVM method could detect the tree crowns with a KHAT coefficient of 0.961 which showed a great agreement with the observed samples and overall accuracy of 97.7% that showed the accuracy of the final map. Finally, the authors suggest applying this method to optimize the parameters of classification techniques like SVM.

  9. Parameter optimization of image classification techniques to delineate crowns of coppice trees on UltraCam-D aerial imagery in woodlands

    Science.gov (United States)

    Erfanifard, Yousef; Stereńczak, Krzysztof; Behnia, Negin

    2014-01-01

    Estimating the optimal parameters of some classification techniques becomes their negative aspect as it affects their performance for a given dataset and reduces classification accuracy. It was aimed to optimize the combination of effective parameters of support vector machine (SVM), artificial neural network (ANN), and object-based image analysis (OBIA) classification techniques by the Taguchi method. The optimized techniques were applied to delineate crowns of Persian oak coppice trees on UltraCam-D very high spatial resolution aerial imagery in Zagros semiarid woodlands, Iran. The imagery was classified and the maps were assessed by receiver operating characteristic curve and other performance metrics. The results showed that Taguchi is a robust approach to optimize the combination of effective parameters in these image classification techniques. The area under curve (AUC) showed that the optimized OBIA could well discriminate tree crowns on the imagery (AUC=0.897), while SVM and ANN yielded slightly less AUC performances of 0.819 and 0.850, respectively. The indices of accuracy (0.999) and precision (0.999) and performance metrics of specificity (0.999) and sensitivity (0.999) in the optimized OBIA were higher than with other techniques. The optimization of effective parameters of image classification techniques by the Taguchi method, thus, provided encouraging results to discriminate the crowns of Persian oak coppice trees on UltraCam-D aerial imagery in Zagros semiarid woodlands.

  10. Effects of waterlogging on seed germination of three Mediterranean oak species: Ecological implications

    Science.gov (United States)

    Pérez-Ramos, Ignacio M.; Marañón, Teodoro

    2009-05-01

    Soil water saturation during prolonged periods of time generates a negative impact on nearly all terrestrial plants. In Mediterranean woodlands, precipitation can be very abundant during the wet season, inducing temporary soil waterlogging, coinciding with the seed dispersal and germination time of many species. We investigated the effects of waterlogging on seed germination and early root growth of three coexisting oak species ( Quercus canariensis, Q. suber and Q. pyrenaica), by completely flooding of seeds for various periods of time. The three oak species showed a certain level of tolerance to waterlogging, only being affected those seeds subjected for long periods of submersion (over 30 days). Waterlogging during prolonged periods of time decreased the probability of seed germination in the three oak species, lengthened the time to germination, and hampered root development in two of the studied species. The main differences between oak species occurred in terms of root growth ( Q. canariensis being the less affected, and Q. suber the most); these differential responses could be related to a species rank of waterlogging tolerance. Thus inter-specific differences in germination responses to waterlogging could contribute to explain, at least partially, species habitat and distribution patterns across landscapes. Seed mass also played an important role on different aspects of germination, though its relative importance varied as function of species and waterlogging treatment. The tolerance to stress induced by waterlogging increased with seed mass, but only in the case of Q. canariensis.

  11. Are the long-term effects of mesobrowsers on woodland dynamics substitutive or additive to those of elephants?

    Science.gov (United States)

    O'Kane, Christopher A. J.; Duffy, Kevin J.; Page, Bruce R.; Macdonald, David W.

    2011-09-01

    The large spectrum of existing literature on browser-woodland dynamics, both from savanna and temperate biomes, converges towards concluding that all browsers importantly impact woody plants. In this context a crucial question in the current debate about reintroducing elephant culling, is whether the long-term effects of elephants and mesobrowsers are similar. If the two groups impact the same woody species in the same habitats, sufficiently high biomass-densities of mesobrowsers may, following removal of elephants, continue to heavily impact earlier life-history stages of the same suite of woody plants that elephant impacted, preventing these species from maturing. Thus, as existing mature trees die from natural causes and fade from the system, a similar end-point for woodland structure and composition is achieved. We reviewed 49 years of literature on the savanna browser guild, performing a meta-analysis on the disparate data on the guild's woody plant species use (3677 records) and habitat use (894 records). Mesobrowsers' and elephants' extensive overlap in habitat use and staple woody species diet, together with evidence of their influencing each others' abundance and of their dietary separation increasing with resource depletion, implies that the two groups impact the same core woody species in the same habitats. It therefore seems probable that high biomass-density mesobrowsers may have a long-term substitutive effect to that of elephant on woodland dynamics. Consequently management wanting a particular state of savanna woodland, should consider the biomass-density of both groups, rather than just focus on the system's perceived keystone species. Such principles may also apply to temperate and other systems.

  12. Woodland recovery after suppression of deer: cascade effects for small mammals, wood mice (Apodemus sylvaticus and bank voles (Myodes glareolus.

    Directory of Open Access Journals (Sweden)

    Emma R Bush

    Full Text Available Over the past century, increases in both density and distribution of deer species in the Northern Hemisphere have resulted in major changes in ground flora and undergrowth vegetation of woodland habitats, and consequentially the animal communities that inhabit them. In this study, we tested whether recovery in the vegetative habitat of a woodland due to effective deer management (from a peak of 0.4-1.5 to <0.17 deer per ha had translated to the small mammal community as an example of a higher order cascade effect. We compared deer-free exclosures with neighboring open woodland using capture-mark-recapture (CMR methods to see if the significant difference in bank vole (Myodes glareolus and wood mouse (Apodemus sylvaticus numbers between these environments from 2001-2003 persisted in 2010. Using the multi-state Robust Design method in program MARK we found survival and abundance of both voles and mice to be equivalent between the open woodland and the experimental exclosures with no differences in various metrics of population structure (age structure, sex composition, reproductive activity and individual fitness (weight, although the vole population showed variation both locally and temporally. This suggests that the vegetative habitat--having passed some threshold of complexity due to lowered deer density--has allowed recovery of the small mammal community, although patch dynamics associated with vegetation complexity still remain. We conclude that the response of small mammal communities to environmental disturbance such as intense browsing pressure can be rapidly reversed once the disturbing agent has been removed and the vegetative habitat is allowed to increase in density and complexity, although we encourage caution, as a source/sink dynamic may emerge between old growth patches and the recently disturbed habitat under harsh conditions.

  13. 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

  14. Using remote sensing and biogeographic modeling to understand the oak savannas of the Sheyenne National Grassland, North Dakota, USA

    Science.gov (United States)

    SigdelPhuyal, Mandira

    Oak savannas are valuable and complex ecosystems that provide multiple ecosystem goods and services, including grazing for livestock, watershed regulation, and recreation. These ecosystems of the woodland-prairie ecoregion of the Midwestern United States are, however, in danger of disappearing. The Sheyenne National Grassland, North Dakota, a protected Prairie grassland-savanna, is a representative of such rare habitats, where oak savanna is found at the landscape scale. In this research, I map the distribution patterns of oak savanna in the Sheyenne using a combination of remote sensing and geospatial datasets, including landscape topography, soils, and fire disturbance. Further, I interpret the performance of a suite of advanced Species Distribution Modeling approaches including Maximum Entropy, Random Forest, Generalized Boosted Model, and Classification Tree to analyze the primary environmental and management factors influencing oak distributions at landscape scales. Woody canopy cover was estimated with high classification accuracy (80-95%) for two study areas of the Sheyenne National Grassland. Among the four species distribution modeling approaches tested, the Random Forest (RF) approach provided the best predictive model. RF model parameters indicate that oak trees favor gently sloping locations, on well-drained upland and sandy soils, with north-facing aspect. While no direct data on water relationships were possible in this research, the importance of the topographic and soil variables in the SDM presumably reflect oak preference for locations and soils that are not prone to water saturation, with milder summer temperatures (i.e. northern aspects), providing conditions suitable for seedling establishment and growth. This research increases our understanding of the biogeography of Midwestern tall-grass oak savannas and provides a decision-support tool for oak savanna management.

  15. Simulation of soil water dynamics in a Caragana intermedia woodland in Huangfuchuan watershed

    Institute of Scientific and Technical Information of China (English)

    JIA Haikun; LIU Yinghui; XU Xia; WANG Kun; GAO Qiong

    2007-01-01

    As vegetation coverage increases,soil water content can decrease due to water uptake and evapotranspiration.At a very high level of plant density,poor growth and even mortality can occur due to the decrease of soil water content.Hence,a better understanding of the relationship between soil water content and the density of plants is important to design effective restoration projects.To study these relationships,we developed a soil water dynamic simulation model of a Caragana intermedia woodland under different slope gradient and slope aspect conditions in the Huangfuchuan watershed on the basis of the previous studies and field experiments.The model took into account the major processes that address the relationships of plants and the environment,including soil characteristics,precipitation,infiltration,vegetation transpiration,and soil evaporation.Daily changes in soil water content,transpiration,and evaporation of the Caragana intermedia woodland with different vegetation coverage,slope gradient,and slope aspect were simulated from 1971 to 2000.Based on the model simulations,we determined the functional relationships among soil water content,plant coverage and slope as well as the optimal plant density on flat slopes.We also determined the effects of slope gradient and slope aspect on soil water content.When slope gradient was less than l0~,the optimal plant density was sensitive to slope gradient.In the slope range from 10° to 30°,plant density was not sensitive to slope gradient.Therefore,it is important to consider planting densities on the hillsides with slope gradients less than 10° for reconstructing vegetation.

  16. Carbon, Nitrogen, and Phosphorus Increase in Soil Physical Fractions Following Vegetation Change from Grassland to Woodland

    Science.gov (United States)

    Kantola, I. B.; Boutton, T. W.; Filley, T. R.; Hallmark, C. T.

    2009-12-01

    Woody plant encroachment has been pervasive in grass-dominated ecosystems around the world during the past century due to livestock grazing, fire suppression, and/or changes in climate and atmospheric chemistry. In the Rio Grande Plains of Texas, subtropical thorn woodlands dominated by N-fixing tree legumes have largely replaced grasslands. This dramatic land cover change has increased above- and belowground primary productivity and accelerated rates of biogeochemical processes in the soil. The purpose of this study was to assess the impact of this grassland to woodland transition on C, N, and P concentrations in soil physical fractions that differ in turnover rates. Soil samples (0-10 cm) were collected in remnant grasslands and near the centers of woody plant clusters ranging in age from 15 to 90 yrs in a subtropical savanna parkland in southern Texas. Soils were fractionated by wet sieving into five size and density classes: un-sieved whole soil, free light fraction (density 250 µm), microaggregates (53-250 µm), and free silt and clay (plant-microbe and plant-plant interactions, and successional dynamics in this ecosystem.

  17. The red oak - white oak forests of the Anthracite Region

    Science.gov (United States)

    C. F. Burnham; M. J. Ferree; F. E. Cunningham

    1947-01-01

    The red oak - white oak forests of the Anthracite Region occupy as substantial portion - 28.6 percent or 915,200 acres - of the region's 3,198,400 acres of forest land. These forests have been so heavily cut for lumber and mine timbers during the past 100 years and have been so badly ravaged by fire following these heavy cuttings that in their present condition...

  18. Riparian woodland flora in upland rivers of Western Greece

    Directory of Open Access Journals (Sweden)

    S. ZOGARIS

    2012-12-01

    Full Text Available Although natural riparian woodlands are an important feature that affects the quality of aquatic conditionsin streams and rivers, surveying riparian zone flora is rarely implemented in the Mediterraneancountries. We developed a rapid assessment method for gathering standardized plot-based woody flora andvegetation data from riparian woodlands. In 2005 we surveyed 218 streamside vegetation plots at 109 sitesin upland areas of four major rivers in mainland Greece (Alfios, Acheloos, Arachthos, and Aoos. Herewe describe the survey method and provide selected results from its initial implementation. The simplicityand effectiveness of this survey procedure supports the use of rapid site-based biodiversity surveys for riparianzones alongside aquatic status assessments.

  19. Late pleistocene history of coniferous woodland in the mohave desert.

    Science.gov (United States)

    Wells, P V; Berger, R

    1967-03-31

    Seventeen ancient wood-rat middens, ranging in radiocarbon age from 7400 to 19,500 years and to older than 40,000 years, have been uncovered in the northeastern, north-central, southeastern, and southwestern sectors of the Mohave Desert. Excellent preservation of macroscopic plant materials (including stems, buds, leaves, fruits, and seeds) enables identification of many plant species growing within the limited foraging range of the sedentary wood rat. An approximately synchronous zonal differentiation of vegetation in response to a gradient of elevation on limestone in the northeastern Mohave Desert is apparent from the macrofossil evidence, preserved in wood-rat middens and ground-sloth coprolites, covering a time span bracketed by radiocarbon ages of about 9000 and 10,000 years. XerophilQus juniper woodlands descended to an elevation of 1100 meters, some 600 meters below the present lower limit of woodland (1700 meters) in the latitude of Frenchman Flat. But desert or semidesert shrubs coexisted with the woodland trees throughout much of the span of elevation corresponding to the pluvial lowering of the woodland zone, and the more mesophytic phase of pinyonjuniper woodland was evidently confined to montane habitats at elevations above 1500 meters. Joshua trees, accompanied by desert shrubs, prevailed down to about 600 meters at Gypsum Cave, Nevada, but only the shrubs of the existing warm-desert vegetation occurred at 530 meters near Rampart Cave, Arizona. Pleistocene middens from the southeastern Mohave Desert record a relatively large downward shift of the pinyon-juniper woodland zone, paralleling the remarkably low minimum elevation of the existing woodland zone in that area. The macrofossil evidence speaks for former continuity of the many disjunct stands of woodland vegetation in the Mohave Desert region, at least along the higher divides connecting most of the ranges. However, there is no macrofossil evidence of pluvial continuity of range for the more

  20. Towards a Manitoba Hydro boreal woodland caribou strategy: Outcomes from Manitoba Hydro boreal woodland caribou workshop

    Directory of Open Access Journals (Sweden)

    Fiona E. Scurrah

    2012-03-01

    Full Text Available Manitoba Hydro is responsible for the continued supply of energy to meet the needs of the province and is committed to protecting the environment when planning the construction and operation of its facilities. Corporate policy dictates ongoing improvement of Environmental Management Systems (EMS in order to meet or surpass regulatory requirements. Environmental objectives are reviewed annually and programs are modified when necessary to address improvements in environmental performance. Manitoba Hydro plans and constructs major transmission projects throughout northern Manitoba which includes areas occupied by boreal woodland caribou. In recognition of the potential issues associated with hydro transmission construction in boreal caribou range, Manitoba Hydro hosted an expert workshop on May 8, 2007 to provide objective advice in the development of a draft corporate strategy that effectively directs targeted monitoring and research for environmental assessment and mitigation. The workshop focused on assessing the potential threats to boreal woodland caribou from a transmission line construction and operation perspective, and identifying appropriate approaches in site selection and environmental assessment (SSEA and long-term monitoring and research. A total of nine threat categories were reviewed to determine the degree and magnitude of potential effects that may result from transmission construction and operation; and of the original nine, five final threat categories were delineated. The main elements of the workshop provided strategic approaches for proactive pre-construction monitoring, research on recruitment and mortality for local populations impacted by ROWs and control areas, and various habitat monitoring, management, and mitigation techniques. Research and monitoring priorities have been identified and continued collaboration with Manitoba Conservation and other land users were also identified.

  1. 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.

  2. 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.

  3. 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.

  4. Modelling above-ground carbon dynamics using multi-temporal airborne lidar: insights from a Mediterranean woodland

    Directory of Open Access Journals (Sweden)

    W. Simonson

    2015-09-01

    Full Text Available Woodlands represent highly significant carbon sinks globally, though could lose this function under future climatic change. Effective large-scale monitoring of these woodlands has a critical role to play in mitigating for, and adapting to, climate change. Mediterranean woodlands have low carbon densities, but represent important global carbon stocks due to their extensiveness and are particularly vulnerable because the region is predicted to become much hotter and drier over the coming century. Airborne lidar is already recognized as an excellent approach for high-fidelity carbon mapping, but few studies have used multi-temporal lidar surveys to measure carbon fluxes in forests and none have worked with Mediterranean woodlands. We use a multi-temporal (five year interval airborne lidar dataset for a region of central Spain to estimate above-ground biomass (AGB and carbon dynamics in typical mixed broadleaved/coniferous Mediterranean woodlands. Field calibration of the lidar data enabled the generation of grid-based maps of AGB for 2006 and 2011, and the resulting AGB change were estimated. There was a close agreement between the lidar-based AGB growth estimate (1.22 Mg ha−1 year−1 and those derived from two independent sources: the Spanish National Forest Inventory, and a~tree-ring based analysis (1.19 and 1.13 Mg ha−1 year−1, respectively. We parameterised a simple simulator of forest dynamics using the lidar carbon flux measurements, and used it to explore four scenarios of fire occurrence. Under undisturbed conditions (no fire occurrence an accelerating accumulation of biomass and carbon is evident over the next 100 years with an average carbon sequestration rate of 1.95 Mg C ha−1 year−1. This rate reduces by almost a third when fire probability is increased to 0.01, as has been predicted under climate change. Our work shows the power of multi-temporal lidar surveying to map woodland carbon fluxes and provide parameters for carbon

  5. Modelling above-ground carbon dynamics using multi-temporal airborne lidar: insights from a Mediterranean woodland

    Science.gov (United States)

    Simonson, W.; Ruiz-Benito, P.; Valladares, F.; Coomes, D.

    2016-02-01

    Woodlands represent highly significant carbon sinks globally, though could lose this function under future climatic change. Effective large-scale monitoring of these woodlands has a critical role to play in mitigating for, and adapting to, climate change. Mediterranean woodlands have low carbon densities, but represent important global carbon stocks due to their extensiveness and are particularly vulnerable because the region is predicted to become much hotter and drier over the coming century. Airborne lidar is already recognized as an excellent approach for high-fidelity carbon mapping, but few studies have used multi-temporal lidar surveys to measure carbon fluxes in forests and none have worked with Mediterranean woodlands. We use a multi-temporal (5-year interval) airborne lidar data set for a region of central Spain to estimate above-ground biomass (AGB) and carbon dynamics in typical mixed broadleaved and/or coniferous Mediterranean woodlands. Field calibration of the lidar data enabled the generation of grid-based maps of AGB for 2006 and 2011, and the resulting AGB change was estimated. There was a close agreement between the lidar-based AGB growth estimate (1.22 Mg ha-1 yr-1) and those derived from two independent sources: the Spanish National Forest Inventory, and a tree-ring based analysis (1.19 and 1.13 Mg ha-1 yr-1, respectively). We parameterised a simple simulator of forest dynamics using the lidar carbon flux measurements, and used it to explore four scenarios of fire occurrence. Under undisturbed conditions (no fire) an accelerating accumulation of biomass and carbon is evident over the next 100 years with an average carbon sequestration rate of 1.95 Mg C ha-1 yr-1. This rate reduces by almost a third when fire probability is increased to 0.01 (fire return rate of 100 years), as has been predicted under climate change. Our work shows the power of multi-temporal lidar surveying to map woodland carbon fluxes and provide parameters for carbon

  6. Microfungi in the soil beneath common oak and their effect on Armillaria occurrence

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśna

    2014-08-01

    Full Text Available Microfungal assemblages in a soil beneath 30- and 50·year-old oaks and their 2-year-old stumps were studied using the soil dilution plate method. A total of 98 culturable microfungi were isolated. Compared to the living oaks before felling and the control living oaks, the density of Mortierella macrocystis, Penicillium jonczewskii, Pseudogymnoascus roseus Sporothrix schenckii, Tolypoccladiumum inflatum and Umbelopsis vinacea sigificantly inacased in the soil beneath slumps in the 32- and 52-year-old stands. Density of Aspergillus kanagawaensis, Monodictys lepraria, P. daleae and sterile dematiaceous hyphomycetes increased significantly in the 32-year-old stand and Chrysosporium merdarium in the 52·year-old stand. These fungi are known 'stimulants' of Armillaria rhizomorph formation. It is suggested that the increase in density of Armillaria rhizomorph 'stimulants' in a soil beneath oak stumps may increase the possibility of colonization of stumps by Armillaria.

  7. Spatial pattern of occurrence of epiphytic lichens on oaks in a heterogeneous landscape

    Science.gov (United States)

    Westerberg, Lars M.; Muhammadi, Usman Haider; Bergman, Karl-Olof; Milberg, Per

    2017-10-01

    Quercus robur (oaks) provides an important substrate for many epiphytic lichens, and with increasing age the bark becomes suitable for some rare species. These species may respond to environmental and landscape factors differently, and at different spatial scales. We tested the effect of factors related to the individual tree and the surrounding landscape on the occurrence and richness patterns of lichens species. The study system consisted of 213 oaks selected in a grid system within a 400 km2 heterogeneous oak-rich area in south-eastern Sweden. Oaks had been selected to be relatively uniform in size (circumference 3.1-4.1 m), and as uniformly distributed as possible in the study area. Landscape factors were calculated for various spatial scales (circles with radius ranging from 28 to 1225 m from a studied oak). One of the landscape factors stands out as of general importance - oak density in the surrounding - while the others (amount of forest, water, houses and arable field) had no effects, or weak effects on only some species. Among the tree specific variables, circumference was consistently important (despite ranging from only 3.1-4.1 m) while inconsistent effects were seen by sun exposure of oak trunk (Chaenotheca phaeocephala, Ramalina baltica) and density of shrubs and trees near the tree (Ch. phaeocephala). The occurrence patterns of Cliostomum corrugatum, Ch. phaeocephala, R. baltica and richness (number of eleven target lichens) were best explained by the density of oaks within radii of 401, 199, 199 and 303 m, respectively. In conclusion, our study highlighted the importance of spatial scale for understanding the occurrence of epiphytic lichens and suggests spatial scales and oak densities that could be targeted for landscape and conservation planning.

  8. 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…

  9. The ecology and management of the Miombo woodlands for ...

    African Journals Online (AJOL)

    The ecology and management of the Miombo woodlands for sustainable livelihoods in southern Africa: the case for non-timber forest products. ... This paper examines and reviews some of the work that has been done in the Miombo ecoregion ...

  10. 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...

  11. 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,...

  12. 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

  13. [Spatial patterns of seed dispersal in Hemiptelea davidii woodland in Keerqin sandy land, China].

    Science.gov (United States)

    Yang, Yun-Fei; Bai, Yun-Peng; Li, Jian-Dong; Li, Li

    2010-08-01

    In order to reveal the space expansion potential of Hemiptelea davidii woodland in Keerqin sandy land in China, the quantitative spatial characteristics of the seed rain in the understory and at the woodsides, as well as the seed dispersal patterns at the woodsides and of the isolating trees, were analyzed through survey on sequential sampling away from seed source in different directions at the woodsides and isolating trees and random sampling in the understory. The results showed that among three sampling plots, the average density of the seed rain in the understory was the highest (13732.5 +/- 3106.2 seeds x m(-2)). For isolating trees, the seed rain had the highest density (5449.4 +/- 1429.3 seeds x m(-2)) in southeast transect, being significantly higher than that in other directions, and the lowest one (650.2 +/- 631.6 seeds x m(-2)) in the northwest transect, being significantly lower than that in other directions. At the woodsides, the seed rain density was significantly higher in the east and south transects than in the west and north transects. The variation of the seed density was greater, with the variation coefficient being 25.7%-106.3% in different directions in the two plots of isolating trees and woodsides. Same as other anemochorous plants, H. davidii had the characteristics of seed dispersal away from the seed source. In the eight sampling transects, there existed diversity in the patterns of the seed dispersal away from the seed source in per unit area and in accumulated area, including linear, power, exponential, quadratic parabola, and logarithmic functions. It was suggested that the space expansion potential of H. davidii woodland in Keerqin sandy land would be greater in more frequency down wind directions such as the south, southeast, and east than in more frequency upwind directions such as the north, northwest, and west.

  14. 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.

  15. Canopy recovery of pedunculate oak, Turkey oak and beech trees after severe defoliation by gypsy moth (Lymantria dispar: Case study from Western Hungary

    Directory of Open Access Journals (Sweden)

    Csóka György

    2015-09-01

    Full Text Available We investigated the canopy recovery of 3 tree species (pedunculate oak, Turkey oak, European beech at two locations in the Veszprém county (Western Hungary after severe defoliation by gypsy moth caterpillars in the spring of 2005. The Turkey oak has evidently the best recovery potential, and it almost completely replaced the lost foliage in 4 months. The pedunculate oak and beech needed 2 years to reach the same level of recovery. The pedunculate oak suffered from a heavy infection of Microsphaera alphitoides after defoliation and it probably slowed down its recovery. Neither the presence of Agrilus biguttatus in the oak plot nor the appearance of Agrilus viridis in the beech plot was observed during the study period. Population density of the buprestid Coraebus floerentinus showed a considerable increase in the oak plot, but remained under the damage level. Neither other harmful appearance of other pests nor significant tree mortality were observed within 4 years from the defoliation. These results provide information for the evaluation of longer term influences of the gypsy moth defoliation and may support the decisions concerning pest control.

  16. Sustaining northern red oak forests: managing oak from regeneration to canopy dominance in mature stands

    Science.gov (United States)

    Daniel C. Dey; Gary W. Miller; John M. Kabrick

    2008-01-01

    Across the range of northern red oak, managers have problems sustaining current stocking of northern red oak in forests. Oak species are adapted to frequent stand disturbances that reduce the abundance of shade tolerant competitors and control fast-growing pioneer species. A widely recommended approach to regenerating northern red oak is to develop relatively large...

  17. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  19. The role of habitat patches on mammalian diversity in cork oak agroforestry systems

    Science.gov (United States)

    Rosalino, Luis M.; Rosário, João do; Santos-Reis, Margarida

    2009-07-01

    Habitat patches, depending on the degree of differentiation from the matrix, can add few or many elements to the species pool of a particular landscape. Their importance to biodiversity is particularly relevant in areas with complex landscapes, where natural, naturalized, or managed habitats are interspersed by small patches of habitat types with very different biophysical characteristics; e.g., fruit orchards and riparian areas. This is the case of the montado landscape, a cork oak agroforestry system that largely covers south-western Portugal. We evaluated whether the high mammalian biodiversity found in this system is, in part, the cumulative result of the species found in the non-matrix habitats. Our results indicate that in areas where there are inclusions of orchards/olive yards and riparian vegetation in the cork oak woodland, a significantly higher number of mammalian species are present. We further detected a positive effect of low human disturbance on mammal diversity. Ultimately, our results can be used by managers to augment their management options, since we show that the inclusion and maintenance of non-matrix habitat patches in cork oak agro-silvo-forestry systems can help to maximize mammal biodiversity without compromising services associated with agriculture and forestry.

  20. Contact allergy to oak moss

    DEFF Research Database (Denmark)

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

    2003-01-01

    a method developed for the identification of contact allergens present in natural complex mixtures to oak moss absolute. The method is based on the combination of bioassay-guided chemical fractionation, gas chromatography-mass spectrometry analysis and structure-activity relationship studies. Our first......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...

  1. Carbon Stock Potential of Oak and Pine Forests in Garhwal Region in Indian Central Himalayas

    Directory of Open Access Journals (Sweden)

    Nanda Nautiyal

    2013-05-01

    Full Text Available Oak (Quercus leucotichophora and pine (Pinus roxburghii are the two most dominant forest types occurring in Indian Central Himalayas. CO2 mitigation potential of these two forest types was observed in the present study. Carbon stock densities for AGTB, BB, LHG, DWS, AGSB and SOC were estimated and higher values were recorded in oak forest stands. Total carbon density estimated was 2420.54 Mg/ha for oak forest of Gopeshwar and 986.93 Mg/ha for pine forest of Nandprayag. CO2 mitigation potential of oak forest of Gopeshwar was recorded to be 8,713.94 CO2e and of pine forests 3552.95 CO2e.

  2. 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

  3. Oaks belowground: mycorrhizas, truffles, and small mammals

    Science.gov (United States)

    Jonathan Frank; Seth Barry; Joseph Madden; Darlene Southworth

    2008-01-01

    Oaks depend on hidden diversity belowground. Oregon white oaks (Quercus garryana) form ectomycorrhizas with more than 40 species of fungi at a 25-ha site. Several of the most common oak mycorrhizal fungi form hypogeous fruiting bodies or truffles in the upper layer of mineral soil. We collected 18 species of truffles associated with Oregon white...

  4. 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 (...

  5. Changes in densities of Sahelian bird species in response to recent ...

    African Journals Online (AJOL)

    Changes in densities of Sahelian bird species in response to recent habitat ... pronounced, due to anthropogenic effects and (potentially) climate change. ... We predicted declines in the abundance of woodland bird species with deforestation.

  6. 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.

  7. The shifting phenological landscape: Within- and between-species variation in leaf emergence in a mixed-deciduous woodland.

    Science.gov (United States)

    Cole, Ella F; Sheldon, Ben C

    2017-02-01

    Many organisms rely on synchronizing the timing of their life-history events with those of other trophic levels-known as phenological matching-for survival or successful reproduction. In temperate deciduous forests, the extent of matching with the budburst date of key tree species is of particular relevance for many herbivorous insects and, in turn, insectivorous birds. In order to understand the ecological and evolutionary forces operating in these systems, we require knowledge of the factors influencing leaf emergence of tree communities. However, little is known about how phenology at the level of individual trees varies across landscapes, or how consistent this spatial variation is between different tree species. Here, we use field observations, collected over 2 years, to characterize within- and between-species differences in spring phenology for 825 trees of six species (Quercus robur, Fraxinus excelsior, Fagus sylvatica, Betula pendula, Corylus avellana, and Acer pseudoplatanus) in a 385-ha woodland. We explore environmental predictors of individual variation in budburst date and bud development rate and establish how these phenological traits vary over space. Trees of all species showed markedly consistent individual differences in their budburst timing. Bud development rate also varied considerably between individuals and was repeatable in oak, beech, and sycamore. We identified multiple predictors of budburst date including altitude, local temperature, and soil type, but none were universal across species. Furthermore, we found no evidence for interspecific covariance of phenology over space within the woodland. These analyses suggest that phenological landscapes are highly complex, varying over small spatial scales both within and between species. Such spatial variation in vegetation phenology is likely to influence patterns of selection on phenology within populations of consumers. Knowledge of the factors shaping the phenological environments

  8. Woodland Survey of Great Britain 1971-2001

    Science.gov (United States)

    Wood, C. M.; Smart, S. M.; Bunce, R. G. H.

    2015-08-01

    The Woodland Survey of Great Britain is a unique data set, consisting of a detailed range of ecological measurements at a national scale, covering a time span of 30 years. A set of 103 woods spread across Britain were first surveyed in 1971, which were again surveyed in 2000-2003 (for convenience referred to subsequently as the "2001 survey"). Standardised methods of describing the trees, shrubs, ground flora, soils and general habitats present were used for both sets of surveys. The sample of 1648 plots spread through 103 woodland sites located across Britain makes it probably the most extensive quantitative ecological woodland survey undertaken in Britain; it is also notable for the range of sites that have been revisited after such a long interval. The data set provides a unique opportunity to explore the effects of a range of potential drivers of woodland change that operated between 1971 and 2001. The data set is available in four discrete parts, which have been assigned the following DOIs: 10.5285/4d93f9ac-68e3-49cf-8a41-4d02a7ead81a (Kirby et al., 2013b), 10.5285/d6409d40-58fe-4fa7-b7c8-71a105b965b4 (Kirby et al., 2013d), 10.5285/fb1e474d-456b-42a9-9a10-a02c35af10d2 (Kirby et al., 2013c), 10.5285 (Kirby et al., 2013a).

  9. Arborealities: The Tactile Ecology of Hardy’s Woodlanders

    OpenAIRE

    William A. Cohen

    2014-01-01

    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...

  10. Workshop: Conserving woodland caribou in the managed forest

    Directory of Open Access Journals (Sweden)

    George Hamilton et al.

    1998-03-01

    Full Text Available A workshop was held August 19 to foster discussion and debate on issues related to conservation of woodland caribou in the managed forest. Six panelists were invited to make brief presentations on their points of view on this subject. They were Don Thomas (Canadian Wildlife Service; Hartley Multimaki (Buchanan Forest Products; Colin Edey (NOVA Corporation; Jerry English (Ontario Ministry of Natural Resources - retired; Dale Seip (British Columbia Ministry of Forests and Harold Cumming (Lakehead University - retired.

  11. Changes in Woodland Use from Longleaf Pine to Loblolly Pine

    OpenAIRE

    John Schelhas; Indrajit Majumdar; Yaoqi Zhang

    2010-01-01

    There is growing evidence suggesting that the United States’ roots are not in a state of “pristine” nature but rather in a “human-modified landscape” over which Native people have since long exerted vast control and use. The longleaf pine is a typical woodland use largely shaped by fires, lightning and by Native Americans. The frequent fires, which were used to reduce fuels and protect themselves from wildfires, enhance wildlife habitats and for hunting, protect themselves from predators and ...

  12. Oak Ridge callibration recall program

    Energy Technology Data Exchange (ETDEWEB)

    Falter, K.G.; Wright, W.E. [Oak Ridge National Lab., TN (United States); Pritchard, E.W. [Oak Ridge Centers for Manufacturing Technology, TN (United States)] [and others

    1996-12-31

    A development effort was initiated within the Oak Ridge metrology community to address the need for a more versatile and user friendly tracking database that could be used across the Oak Ridge complex. This database, which became known as the Oak Ridge Calibration Recall Program (ORCRP), needed to be diverse enough for use by all three Oak Ridge facilities, as well as the seven calibration organizations that support them. Various practical functions drove the initial design of the program: (1) accessible by any user at any site through a multi-user interface, (2) real-time database that was able to automatically generate e-mail notices of due and overdue measuring and test equipment, (3) large memory storage capacity, and (4) extremely fast data access times. In addition, the program needed to generate reports on items such as instrument turnaround time, workload projections, and laboratory efficiency. Finally, the program should allow the calibration intervals to be modified, based on historical data. The developed program meets all of the stated requirements and is accessible over a network of computers running Microsoft Windows software.

  13. Acorn production in red oak

    Science.gov (United States)

    Daniel C. Dey

    1995-01-01

    Manipulation of stand stocking through thinning can increase the amount of oak in the upper crown classes and enhance individual tree characteristics that promote good acorn production. Identification of good acorn producers before thinning or shelterwood harvests can be used to retain them in a stand. Stocking charts can be used to time thinnings and to estimate acorn...

  14. Poison ivy - oak - sumac rash

    Science.gov (United States)

    ... to identify poison ivy, oak, and sumac. Teach children to identify them as soon as they are able to learn about these plants. Remove these plants if they grow near your home (but never burn them). Be aware of plant resins carried by ...

  15. Predicting Polylepis distribution: vulnerable and increasingly important Andean woodlands

    Directory of Open Access Journals (Sweden)

    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.

  16. Arborealities: The Tactile Ecology of Hardy’s Woodlanders

    Directory of Open Access Journals (Sweden)

    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

  17. Environmental drivers of ectomycorrhizal communities in Europe's temperate oak forests.

    Science.gov (United States)

    Suz, Laura M; Barsoum, Nadia; Benham, Sue; Dietrich, Hans-Peter; Fetzer, Karl Dieter; Fischer, Richard; García, Paloma; Gehrman, Joachim; Kristöfel, Ferdinand; Manninger, Miklós; Neagu, Stefan; Nicolas, Manuel; Oldenburger, Jan; Raspe, Stephan; Sánchez, Gerardo; Schröck, Hans Werner; Schubert, Alfred; Verheyen, Kris; Verstraeten, Arne; Bidartondo, Martin I

    2014-11-01

    Ectomycorrhizal fungi are major ecological players in temperate forests, but they are rarely used in measures of forest condition because large-scale, high-resolution, standardized and replicated belowground data are scarce. We carried out an analysis of ectomycorrhizas at 22 intensively monitored long-term oak plots, across nine European countries, covering complex natural and anthropogenic environmental gradients. We found that at large scales, mycorrhizal richness and evenness declined with decreasing soil pH and root density, and with increasing atmospheric nitrogen deposition. Shifts in mycorrhizas with different functional traits were detected; mycorrhizas with structures specialized for long-distance transport related differently to most environmental variables than those without. The dominant oak-specialist Lactarius quietus, with limited soil exploration abilities, responds positively to increasing nitrogen inputs and decreasing pH. In contrast, Tricholoma, Cortinarius and Piloderma species, with medium-distance soil exploration abilities, show a consistently negative response. We also determined nitrogen critical loads for moderate (9.5-13.5 kg N/ha/year) and drastic (17 kg N/ha/year) changes in belowground mycorrhizal root communities in temperate oak forests. Overall, we generated the first baseline data for ectomycorrhizal fungi in the oak forests sampled, identified nitrogen pollution as one of their major drivers at large scales and revealed fungi that individually and/or in combination with others can be used as belowground indicators of environmental characteristics.

  18. Evaluation Model of the Ecology Benefit Value of Woodland in China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Main influencing factors affecting the ecology benefit value of woodland are analyzed,mainly including the water conservation value,environment cleaning value,water and soil conservation value,and climate regulation value.Evaluation model of the ecology benefit value of woodland is put forward which can deal with the uncertain information.Method for determining index weights is discussed,as well as the processing method for uncertain information during the evaluation of ecology benefit value of woodland.Finally,the feasibility and convenience of the evaluation model of the woodland ecology benefit value are illustrated with examples.

  19. [Vertical distribution characteristics of N2O emission in tea garden and its adjacent woodland].

    Science.gov (United States)

    Fan, Li-chao; Han, Wen-yan; Li, Xin; Li, Zhi-xin

    2015-09-01

    In this study, we determined the vertical distribution of N2O emission rates in tea soils and its adjacent woodland soils. The results showed that total nitrogen contents, N2O fluxes and cumulative emissions in the tea garden and woodland decreased with the increasing depth of the soil layer, and their average values were greater in tea garden than in woodland. Generally, pH, soil water soluble organic nitrogen (WSON), soil microbial biomass nitrogen (MBN), NO(3-)-N and NH(4+)-N contents had a downward trend with the increasing depth of soil layer. The WSON, MBN, NO(3-)-N and NH(4+)-N contents from each soil layer were greater in tea garden than in woodland, but the pH value in tea garden was lower than that in woodland. The N2O emission rate was significantly positively related with TN, MBN and NH(4+)-N contents, but not with pH value. The N2O emission rate was significantly correlated with WSON content in woodland, but not in tea garden. The N20 emission rate was significantly correlated with NO(3-)-N concentration in tea garden, but not in woodland. WSON/TN and N2O-N/SMBN were averagely greater than in tea garden in woodland, and SMBN/TN was opposite. These results indicated that tea soil was not conducive to accumulate nitrogen pool, maintain soil quality and its sustainable use compared to woodland.

  20. 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

  1. Four-year comparison of water contents beneath a grass ley and a deciduous oak wood overlying Triassic sandstone in lowland England

    Science.gov (United States)

    Green, Julian C.; Reid, Ian; Calder, Ian R.; Nisbet, Thomas R.

    2006-09-01

    SummaryDifferences in the seasonal water dynamics of a sand soil overlying Triassic sandstone have been investigated to a depth of 9 m beneath both a grass ley and a pendunculate oak woodland within Clipstone Forest, Nottinghamshire, England. Fortnightly measurements with a neutron-probe over a four-year period allowed a comparison of the soil-rock water content to depths rarely reported. In spring, the rate of decrease of water content of the uppermost 2 m of soil was much greater under grass than oak woodland. In contrast, the rate of decrease under oak was greater after leafing out in May, while the rate of rewetting in early autumn was lower for this land-use until senescence and leaf-fall in late autumn. In the uppermost 2 m of soil - a depth that includes all plant roots - the soil moisture minima were between 47 and 58 mm lower under oak than grass in each year of monitoring. As a result of both these drier conditions and the comparatively late leaf fall of this species, penetration of the winter-season wetting front to 2 m was delayed by between one and three months at the oak site relative to grass in years of near-average rainfall. Rewetting at 9 m lags by 10-12 months, compared to the surface, giving an average penetration rate for the wetting front to this depth of 25-30 mm day -1, with little observable differences between the land-uses. Preferential flow is evident under both sites, affecting the profile to 3 m in all years and to at least 6 m following winters experiencing exceptional rainfall.

  2. Historical fire and multidecadal drought as context for piñon-juniper woodland restoration in western Colorado.

    Science.gov (United States)

    Shinneman, Douglas J; Baker, William L

    2009-07-01

    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, U.S.A., 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 approximately 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-rotation, high

  3. Population variation and natural selection on leaf traits in cork oak throughout its distribution range

    Science.gov (United States)

    Ramírez-Valiente, José Alberto; Valladares, Fernando; Sánchez-Gómez, David; Delgado, Antonio; Aranda, Ismael

    2014-07-01

    A central issue in evolutionary biology is the exploration of functional trait variation among populations and the extent to which this variation has adaptive value. It was recently proposed that specific leaf area (SLA), leaf nitrogen concentration per mass (Nmass) and water use efficiency in cork oak play an important role in adaptation to water availability in the environment. In order to investigate this hypothesis, we explored, first, whether there was population-level variation in cork oak (Quercus suber) for these functional traits throughout its distribution range; if this were the case, it would be consistent with the hypothesis that different rainfall patterns have led to ecotypic differentiation in this species. Second, we studied whether the population-level variation matched short-term selection on these traits under different water availability conditions using two fitness components: survival and growth. We found high population-level differentiation in SLA and Nmass, with populations from dry places exhibiting the lowest values for SLA and Nmass. Likewise, reduced SLA had fitness benefits in terms of growth for plants under dry conditions. However, contrary to our expectations, we did not find any pattern of association between functional traits and survival in nine-year-old saplings despite considerable drought during one year of the study period. These results together with findings from the literature suggest that early stages of development are the most critical period for this species. Most importantly, these findings suggest that cork oak saplings have a considerable potential to cope with dry conditions. This capacity to withstand aridity has important implications for conservation of cork oak woodlands under the ongoing climate change.

  4. 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.

  5. BIFoR FACE: A Free-Air Carbon Dioxide Enrichment (FACE) facility in old-growth temperate deciduous woodland

    Science.gov (United States)

    MacKenzie, Rob; Thomas, Rick; Ellsworth, David; Hemming, Debbie; Crous, Kristine; Blaen, Phillip; Poynter, Alex; Blenkhorn, Daniel; Pope, Francis

    2016-04-01

    The Birmingham Institute of Forest research (BIFoR) focuses on fundamental physical, biological, ecological, social and cultural research of direct relevance to forested landscapes worldwide. A core platform for BIFoR is a Free-Air Carbon Dioxide Enrichment (FACE) facility, with which we study the ten-year response of a mature temperate deciduous forest ecosystem to a 150-ppmv step-change in atmospheric [CO2]. BIFoR FACE is being established in Mill Haft, a mature (~150 year-old) oak (Quercus robur) and hazel (Corylus avellana) coppice-with-standards woodland in central England, UK. The facility enables elevated CO2 (eCO2) treatments to be introduced in 30 m diameter rings (3 treatment plots, 3 fully-replicated control plots, and 3 unmodified ambient controls). Primary research questions focus on carbon uptake and storage, corresponding nutrient limitations, and biodiversity and ecosystem responses to elevated CO2. Here we describe the facility and experimental design, and present baseline data collected through the growing season of 2015. These data include: biophysical tree properties; atmospheric CO2/H2O fluxes; airborne and ground laser scatterometry; leaf area index; geophysical survey data; canopy phenology; soil and water chemical and physical properties; and invertebrate surveys. Data from an intensive campaign conducted during august 2015 are also shown, including in- and above- canopy characterisation of biogenic VOCs using a Proton Transfer Reaction Mass Spectrometer, aerosol loading including bioaerosols, and air quality. Further campaign results are presented from leaf level photosynthetic carbon-dioxide response curve (A/Ci) performed at different canopy heights on oak trees, and on the dominant understory species - hazel and sycamore (Acer pseudoplatanus) across the site. BIFoR FACE is intended to be an international facility for forest science - ideas for collaborations are encouraged. Please see http

  6. 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.

  7. Population ecology of vervet monkeys in a high latitude, semi-arid riparian woodland

    Directory of Open Access Journals (Sweden)

    Graham Pasternak

    2013-02-01

    Full Text Available Narrow riparian woodlands along non-perennial streams have made it possible for vervet monkeys to penetrate the semi-arid karoo ecosystem of South Africa, whilst artificial water points have more recently allowed these populations to colonize much more marginal habitat away from natural water sources. In order to better understand the sequelae of life in these narrow, linear woodlands for historically ‘natural’ populations and to test the prediction that they are ecologically stressed, we determined the size of troops in relation to their reliance on natural and artificial water sources and collected detailed data from two river-centred troops on activity, diet and ranging behaviour over an annual cycle. In comparison to other populations, our data indicate that river-centred troops in the karoo were distinctive primarily both for their large group sizes and, consequently, their large adult cohorts, and in the extent of home range overlap in what is regarded as a territorial species. Whilst large group size carried the corollary of increased day journey length and longer estimated interbirth intervals, there was little other indication of the effects of ecological stress on factors such as body weight and foraging effort. We argue that this was a consequence of the high density of Acacia karroo, which accounted for a third of annual foraging effort in what was a relatively depauperate floristic habitat. We ascribed the large group size and home range overlap to constraints on group fission.Conservation implications: The distribution of group sizes, sampled appropriately across habitats within a conservation area, will be of more relevance to management than average values, which may be nothing more than a statistical artefact, especially when troop sizes are bimodally distributed.

  8. Oak Ridge National Laboratory Review

    Energy Technology Data Exchange (ETDEWEB)

    Krause, C.; Pearce, J.; Zucker, A. (eds.)

    1992-01-01

    This report presents brief descriptions of the following programs at Oak Ridge National Laboratory: The effects of pollution and climate change on forests; automation to improve the safety and efficiency of rearming battle tanks; new technologies for DNA sequencing; ORNL probes the human genome; ORNL as a supercomputer research center; paving the way to superconcrete made with polystyrene; a new look at supercritical water used in waste treatment; and small mammals as environmental monitors.

  9. Great Basin semi-arid woodland dynamics during the late quaternary

    Energy Technology Data Exchange (ETDEWEB)

    Wigand, P.E.; Hemphill, M.L.; Sharpe, S.E. [Univ. and Community College System of Nevada, Reno, NV (United States)] [and others

    1995-09-01

    Semi-arid woodlands have dominated the middle elevations of Great Basin mountain ranges during the Holocene where subalpine woodlands prevailed during the Pleistocene. Ancient woodrat middens, and in a few cases pollen records indicate in the late Pleistocene and early Holocene woodland history lowered elevation of subalpine woodland species. After a middle Holocene retrenchment at elevations in excess of 500 meters above today, Juniper-dominated semi-arid woodland reached its late Holocene maximum areal extent during the Neoglacial (2 to 4 ka). These records, along with others indicate contracting semi-arid woodland after the Neoglacial about 1.9 ka. Desert shrub community expansion coupled with increased precariousness of wetland areas in the southern Great Basin between 1.9 and 1.5 ka coincide with shrinking wet-lands in the west-central and northern Great Basin. Coincident greater grass abundance in northern Great Basin sagebrush steppe, reaching its maximum between 1.5 and 1.2 ka, corresponds to dramatic increases in bison remains in the archaeological sites of the northern Intermontane West. Pollen and woodrat midden records indicate that this drought ended about 1.5 ka. Succeeding ameliorating conditions resulted in the sudden northward and downward expansion of pinon into areas that had been dominated by juniper during the Neoglacial. Maximum areal extent of pinon dominated semi-arid woodland in west-central Nevada was centered at 1.2 ka. This followed by 100 years the shift in dominance from juniper to pinon in southern Nevada semi-arid woodlands. Great Basin woodlands suffered from renewed severe droughts between .5 to .6 ka. Effectively wetter conditions during the {open_quotes}Little Ice Age{close_quotes} resulted in re-expansion of semi-arid woodland. Activities related to European settlement in the Great Basin have modified prehistoric factors or imposed new ones that are affecting woodland response to climate.

  10. Cork oak (Quercus suber L.) site rating

    OpenAIRE

    Gonçalves, Ana Cristina; Saraiva Dias, Susana; Gonçalves Ferreira, Alfredo; Ribeiro, Nuno de Almeida

    2004-01-01

    Alentejo cork oak stands are crucial in terms of cork production and sustainability of agrosilvopastoral systems, therefore the development of a tool that allows site zoning, according to cork oak establishment and growth potentials is worthwhile. The site potential and consequently tree development are mainly governed by soil characteristics such as depth, permeability, chemistry, internal drainage, runoff and climate characteristics such as precipitation and temperature. A cork oak site-rat...

  11. Energy-conserving site design: case study, The Woodlands, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, M

    1980-03-01

    The Woodlands is a HUD Title VII New Town located north of Houston. It includes 22,000 acres and the plan for the new town consists of 6 residential villages, a town center called the Metro Center and several additional tracts, such as the Trade Center for larger-scale industrial use. Each village is to be structured around one large and several supporting neighborhood centers. Ultimate population is planned to be 150,000. Included in this report are sections on background, team structure and organization, methodological considerations, the conventional and energy-conserving plan, constraints to implementation, and general conclusions and next phases.

  12. Extreme Drought Event and Shrub Invasion Reduce Oak Trees Functioning and Resilience on Water-Limited Ecosystems

    Science.gov (United States)

    Caldeira, M. C.; Lobo-do-Vale, R.; Lecomte, X.; David, T. S.; Pinto, J. G.; Bugalho, M. N.; Werner, C.

    2016-12-01

    Extreme droughts and plant invasions are major drivers of global change that can critically affect ecosystem functioning. Shrub encroachment is increasing in many regions worldwide and extreme events are projected to increase in frequency and intensity, namely in the Mediterranean region. Nevertheless, little is known about how these drivers may interact and affect ecosystem functioning and resilience Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event in a Mediterranean oak woodland, we show that the combination of native shrub invasion and extreme drought reduced ecosystem transpiration and the resilience of the key-stone oak tree species. We established six 25 x 25 m paired plots in a shrub (Cistus ladanifer L.) encroached Mediterranean cork-oak (Quercus suber L.) woodland. We measured sapflow and pre-dawn leaf water potential of trees and shrubs and soil water content in all plots during four years. We determined the resilience of tree transpiration to evaluate to what extent trees recovered from the extreme drought event. From February to November 2011 we conducted baseline measurements for plot comparison. In November 2011 all the shrubs from one of all the paired plots were cut and removed. Ecosystem transpiration was dominated by the water use of the invasive shrub, which further increased after the extreme drought. Simultaneously, tree transpiration in invaded plots declined more sharply (67 ± 13 %) than in plots cleared from shrubs (31 ± 11%) relative to the pre-drought year (2011). Trees in invaded plots were not able to recover in the following wetter year showing lower resilience to the extreme drought event. Our results imply that in Mediterranean-type of climates invasion by water spending species coupled with the projected recurrent extreme droughts will cause critical drought tolerance thresholds of trees to be overcome, thus increasing the probability of tree mortality.

  13. Conservation opportunities in Spanish Juniper Juniperus thurifera woodlands: the case of migratory thrushes Turdus spp.

    NARCIS (Netherlands)

    Telleria, J.L.; De la Hera, I.; Ramírez, A.; Santos, T.

    2011-01-01

    Conservation opportunities in Spanish juniper Juniperus thurifera woodlands: the case of migratory thrushes Turdus spp. Spanish juniper Juniperus thurifera woodlands are the core habitat of several sites included in the Nature 2000 Network and the wintering ground of many European thrushes Turdus

  14. Sagebrush steppe recovery after fire varies by development phase of Juniperus occidentalis woodland

    Science.gov (United States)

    Pinus-Juniperus L. (Piñon- juniper) woodlands have expanded into Artemisia tridentata Beetle (big sagebrush) steppe of the western United States primarily as a result of reduced fire disturbances. Woodland control measures, including prescribed fire, have been increasingly employed to restore sagebr...

  15. Oak wilting in Slovakia. [Ophiostoma; ceratocystis

    Energy Technology Data Exchange (ETDEWEB)

    Lecontovyc, R.; Capek, M.

    1987-03-01

    Wilt disease, a tracheomykosis, is triggered and spread by a complex of detrimental factors involving both natural and anthropogenic environmental influences. These developments and their impact on the health of the oaks are discussed separately. The inadequate water supply, which has multiple causes, leads to outbreaks of phytophagous and xylophagus insect pests; these insects predispose the oak stands to mycosis infection and may even function as vectors. Oak wilt disease-causing fungi of the genera Ophiostoma/Ceratocystis are listed and their different effect on the various oak species as well as measures to combat them presented.

  16. Minimal role of eastern fence lizards in Borrelia burgdorferi transmission in central New Jersey oak/pine woodlands

    Science.gov (United States)

    Rulison, Eric L.; Kerr, Kaetlyn T; Dyer, Megan C; Han, Seungeun; Burke, Russell L.; Tsao, Jean I.; Ginsberg, Howard S.

    2014-01-01

    The Eastern fence lizard, Sceloporus undulatus, is widely distributed in eastern and central North America, ranging through areas with high levels of Lyme disease, as well as areas where Lyme disease is rare or absent. We studied the potential role of S. undulatus in transmission dynamics of Lyme spirochetes by sampling ticks from a variety of natural hosts at field sites in central New Jersey, and by testing the reservoir competence of S. undulatus for Borrelia burgdorferi in the laboratory. The infestation rate of ticks on fence lizards was extremely low (proportion infested = 0.087, n = 23) compared to that on white footed mice and other small mammals (proportion infested = 0.53, n = 140). Of 159 nymphs that had fed as larvae on lizards that had previously been exposed to infected nymphs, none was infected with B. burgdorferi, compared with 79.9% of 209 nymphs that had fed as larvae on infected control mice. Simulations suggest that changes in the numbers of fence lizards in a natural habitat would have little effect on the infection rate of nymphal ticks with Lyme spirochetes. We conclude that in central New Jersey S. undulatus plays a minimal role in the enzootic transmission cycle of Lyme spirochetes.

  17. Influence of plant community structure on vulnerability to drought of semiarid pine woodlands.

    Science.gov (United States)

    Moreno-Gutiérrez, Cristina; Battipaglia, Giovanna; Cherubini, Paolo; Saurer, Matthias; Siegwolf, Rolf; Querejeta, José Ignacio

    2010-05-01

    The growth, water status and water use efficiency of trees are sensitive to drought. The severity of drought experienced by trees can be magnified or diminished depending on plant community structure and density. This is especially important in semiarid environments. In dense afforested plantations, high inter-tree competition for soil water could increase the water stress of trees in comparison to plants in an open woodland. On the other hand, the shading effect of the tree canopy and the increased soil infiltration capacity in semiarid afforested stands could prevail over competition and buffer the drought effect. Thus, in dense afforested plantations, greater inter-tree competition but more favourable microclimatic conditions may have opposite effects, and the prevalence of one of them could depend on annual meteorological conditions. To test these hypotheses, we made a long term assessment (50 years) of tree ring growth and isotopic composition of Pinus halepensis in two nearby communities: an afforested pine stand and an open pine woodland with under storey (shrub land), both located in semiarid SE Spain (Murcia). We sampled 10 trees per site and we measured tree ring width. The individual time series were detrended and the mean chronology was calculated for each series. On selected five trees per location, the annual δ13C and δ18O were measured on cellulose extracted from latewood. The relationships between measured variables and meteorological (temperature and precipitation) data, provided by the Spanish Agency of Meteorology, were statistically assessed with linear regression analyses. We found a strong significant correlation between the standardized mean chronologies of pines in both communities. In both sites, the mean sensitivity of the mean chronologies was high: 0.37 in the open pine woodland (ow) and 0.54 in the afforested stand (as), suggesting that the individual growth series have a clear common signal. Our results show significant positive

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

    Directory of Open Access Journals (Sweden)

    B. M. Campbell

    1995-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    B. M. Campbell

    1995-12-01

    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.

  20. 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.

  1. The impact of broadleaved woodland on water resources in lowland UK: III. The results from Black Wood and Bridgets Farm compared with those from other woodland and grassland sites

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available In the United Kingdom the planting of broadleaved woodland has led to concerns about the impact on water resources. Comparative studies, typically using soil water measurements, have been established to compare water use of broadleaved woodland and grassland. The diversity of outcomes from these studies makes it difficult to make any consistent prediction of the hydrological impact of afforestation. Most studies have shown greater drying of soils under broadleaved woodland than under grass. However, two studies in a beech wood growing on shallow soils above chalk at Black Wood, Micheldever, Hampshire showed little overall difference between broadleaved woodland and grass, either in soil water abstraction or in evaporation. Two factors are thought to contribute to the different results from Black Wood. It is known that evaporation can be considerably enhanced at the edges of woodlands or in small areas of woodlands. The studies at Black Wood were made well within a large area of fairly uniform woodland. Other studies in which a difference occurred in soil drying between broadleaved woodland and grass used measurements made in small areas of woodlands or at woodland edges. Another important difference between comparison of woodland at Black Wood and grassland growing nearby, also on shallow soils above Chalk, compared to other broadleaved woodland/grass comparisons, growing on other geologies, is the influence of the Chalk. Although vegetation such as grass (and woodland does not populate the chalk profusely with roots, water can be removed from the Chalk by the roots which proliferate at the soil/chalk interface and which can generate upward water movement within the Chalk. Published work showed that only in a very dry summer did the evaporation from grass growing on shallow soils above chalk fall below potential. In broadleaved woodland/grass comparisons on non-chalky soils it is possible that moisture deficits in the soil below the grass may

  2. Changes in Woodland Use from Longleaf Pine to Loblolly Pine

    Directory of Open Access Journals (Sweden)

    John Schelhas

    2010-08-01

    Full Text Available There is growing evidence suggesting that the United States’ roots are not in a state of “pristine” nature but rather in a “human-modified landscape” over which Native people have since long exerted vast control and use. The longleaf pine is a typical woodland use largely shaped by fires, lightning and by Native Americans. The frequent fires, which were used to reduce fuels and protect themselves from wildfires, enhance wildlife habitats and for hunting, protect themselves from predators and enemy tribes, led to the establishment of the fire dependent and fire tolerant longleaf pine across the southern landscape. In the last 3 centuries however, the range of longleaf ecosystem has been gradually replaced first by agriculture and then by loblolly pine farming. The joint effects of agricultural expansion, intense logging of the longleaf in the late 1800s, expanded fire control since the early 20th century, and subsequent bare-root planting beginning in the 1930s, has permitted loblolly pine to become dominantly established in the south. Longleaf and loblolly pines represent two distinct woodland uses and represent separate human values. This study investigated the change from longleaf pine use to loblolly pine farming in Southern US from perspectives of human values of land and natural resources.

  3. Occupational poison ivy and oak dermatitis.

    Science.gov (United States)

    Epstein, W L

    1994-07-01

    Among the growing and diverse groups of outdoor and environmental workers, poison ivy and poison oak continue to be the major cause of occupational contact dermatitis. This article reviews the practical and theoretic means to prevent poison ivy and poison oak dermatitis in workers occupationally exposed to these weeds.

  4. 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.

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

    Science.gov (United States)

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

    2016-12-14

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    Sheffer, Efrat; Canham, Charles D; Kigel, Jaime; Perevolotsky, Avi

    2014-01-01

    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 understanding species

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

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Schaich, H.

    2014-01-01

    . Mean diameters and species richness values are high. Typical socialist woodland species are nonnative (mean 35 %) and/or coniferous (mean 51 %). Stands have a uniform, even-aged stand structure. Species richness/diversity indices are generally low. Postsocialist woodlands exhibit a high degree...... of variability. Percentages of nonnative (7 %) and coniferous (10 %) individuals are low. The findings suggest that socialist and postsocialist farmland and forest policies translated into distinct land-use legacies in the newly established farm woodlands, which differ considerably from the composition...

  9. 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.

  10. Surveying woodland raptors by broadcast of conspecific vocalizations

    Science.gov (United States)

    Mosher, J.A.; Fuller, M.R.; Kopeny, M.

    1990-01-01

    We surveyed for raptors in forests on study areas in five of the eastern United States. For Cooper's Hawks (Accipiter cooperi), Red-shouldered Hawks (Buteo lineatus), and Barred Owls (Strix varia) the contact rates obtained by broadcasting taped vocalizations of conspecifics along roads were significantly greater than contact rates obtained by only looking and listening from the roadside. Broad-winged Hawks (B. platypterus) were detected only after their calls were broadcast. Most raptors were detected within 10 min of the beginning of the broadcasts. Red-tailed Hawks (B. jamaicensis) and Goshawks (A. gentilis) nested infrequently on our study areas, and we were unable to increase detections of these species. Generally, point count transects along woodland roads, from which conspecific vocalizations were broadcast, resulted in higher species specific detection rates than when walking, driving continuously, or only looking and listening for raptors at roadside stops.

  11. Preliminary research on environmental impact of woodland grazing by pigs

    Directory of Open Access Journals (Sweden)

    Danilo Mani

    2010-01-01

    Full Text Available 6 castrate pigs about 30 kg live weight each entered in a fence into hilly woodland area. The pigs were bred until about 140 kg live weight. After 10 months of pasture breeding, the environmental damages (cover ground, plants and soil characteristics by rooting and trampling were evaluated. The damages to cover ground and to shrubs and to physical structure (Fissures and Aggregate stability caused hydro-geological instability with soil erosion and landslides. Removing surface layers of soil caused considerable loss of organic matter (Total Organic Carbon and Total Nitrogen, microbial activity (Microbial ATP and breathing and enzyme activity changes (Total β−glucosidase and Extra cellular β−glucosidase. Damages to native plants are different in relation to the root and the trunk kinds, and to the palatability of leaves and apexes which result inversely related whit the abundance of disagreeable substances content (ADL, Tannins, Resins, Latex.

  12. SGR: an online genomic resource for the woodland strawberry.

    Science.gov (United States)

    Darwish, Omar; Slovin, Janet P; Kang, Chunying; Hollender, Courtney A; Geretz, Aviva; Houston, Sam; Liu, Zhongchi; Alkharouf, Nadim W

    2013-12-23

    Fragaria vesca, a diploid strawberry species commonly known as the alpine or woodland strawberry, is a versatile experimental plant system and an emerging model for the Rosaceae family. An ancestral F. vesca genome contributed to the genome of the octoploid dessert strawberry (F. ×ananassa), and the extant genome exhibits synteny with other commercially important members of the Rosaceae family such as apple and peach. To provide a molecular description of floral organ and fruit development at the resolution of specific tissues and cell types, RNAs from flowers and early developmental stage fruit tissues of the inbred F. vesca line YW5AF7 were extracted and the resulting cDNA libraries sequenced using an Illumina HiSeq2000. To enable easy access as well as mining of this two-dimensional (stage and tissue) transcriptome dataset, a web-based database, the Strawberry Genomic Resource (SGR), was developed. SGR is a web accessible database that contains sample description, sample statistics, gene annotation, and gene expression analysis. This information can be accessed publicly from a web-based interface at http://bioinformatics.towson.edu/strawberry/Default.aspx. The SGR website provides user friendly search and browse capabilities for all the data stored in the database. Users are able to search for genes using a gene ID or description or obtain differentially expressed genes by entering different comparison parameters. Search results can be downloaded in a tabular format compatible with Microsoft excel application. Aligned reads to individual genes and exon/intron structures are displayed using the genome browser, facilitating gene re-annotation by individual users. The SGR database was developed to facilitate dissemination and data mining of extensive floral and fruit transcriptome data in the woodland strawberry. It enables users to mine the data in different ways to study different pathways or biological processes during reproductive development.

  13. Ecohydrologic relationships of two juniper woodlands with different precipitation regimes

    Science.gov (United States)

    Ochoa, C. G.; Guldan, S. J.; Deboodt, T.; Fernald, A.; Ray, G.

    2015-12-01

    The significant expansion of juniper (Juniperus spp.) woodlands throughout the western U.S. during the last two centuries has disrupted important ecological functions and hydrologic processes. The relationships between water and vegetation distribution are highly impacted by the ongoing shift from shrub steppe and grassland to woodland-dominated landscapes. We investigated vegetation dynamics and hydrologic processes occurring in two distinct juniper landscapes with different precipitation regimes in the Intermountain West region: A winter snow-dominated (Oregon) and a summer rain-dominated with some winter precipitation (New Mexico) landscape. Results from the Oregon site showed marginal differences (1-2%) in soil moisture in treated vs untreated watersheds throughout the dry and wet seasons. In general, soil moisture was greater in the treated watershed in both seasons. Canopy cover affected soil moisture over time. Perennial grass cover was positively correlated with changes in soil moisture, whereas juniper cover was negatively correlated with changes in soil moisture. Shallow groundwater response observed in upland and valley monitoring wells indicate there are temporary hydrologic connections between upland and valley locations during the winter precipitation season. Results from the New Mexico site provided valuable information regarding timing and intensity of monsoon-driven precipitation and the rainfall threshold (5 mm/15 min) that triggers runoff. Long-term vegetation dynamics and hydrologic processes were evaluated based on pre- and post-juniper removal (70%) in three watersheds. In general, less runoff and greater forage response was observed in the treated watersheds. During rainfall events, soil moisture was less under juniper canopy compared with inter-canopy; this difference in soil moisture was intensified during high intensity, short duration rainstorms in the summer months. We found that winter snow precipitation helped recharge soil moisture

  14. Phytoliths in woody plants from the Miombo woodlands of Mozambique.

    Science.gov (United States)

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

    2009-07-01

    There are no descriptions of phytoliths produced by plants from the 'Zambezian' zone, where Miombo woodlands are the dominant element of the largest single phytochorion in sub-Saharan Africa. The preservation of phytoliths in fossil records of Africa makes phytoliths a tool to study early plant communities. Paleo-ethnobotanical interpretation of phytoliths relies on the comparison of ancient types with morphotypes extracted from living reference collections. Phytoliths were extracted from plant samples representing 41 families, 77 genera and 90 species through sonic cleaning, dry ashing and acid treatment; and phytoliths thus extracted were quantified. For each species, an average of 216 phytoliths were counted. The percentage of each morphotype identified per species was calculated, and types were described according to the descriptors from the International Code for Phytolith Nomenclature. Phytolith assemblages were subject to discriminant analysis, cluster analysis and principal component analysis. Phytoliths were grouped into 57 morphotypes (two were articulated forms and 55 were discrete shapes), and provide a reference collection of phytolith assemblages produced by Miombo woody species. Common and unique morphotypes are described and taxonomic and grouping variables are looked into from a statistical perspective. The first quantitative taxonomy of phytoliths from Miombos is presented here, including new types and constituting the most extensive phytolith key for any African ecoregion. Evidence is presented that local woody species are hypervariable silica producers and their phytolith morphotypes are highly polymorphic. The taxonomic significance of these phytoliths is largely poor, but there are important exceptions that include the morphotypes produced by members from >10 families and orders. The typical phytolithic signal that would allow scientists to identify ancient woodlands of 'Zambezian' affiliation comprises only half of the original number of

  15. 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...

  16. 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

  17. 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-...

  18. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Final Critical Habitat for Southern Selkirk Mountains Population of Woodland Caribou (Rangifer tarandus caribou)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of final critical habitat for Rangifer tarandus caribou (Southern Selkirk Mountains population of Woodland Caribou).

  1. Final Critical Habitat for Southern Selkirk Mountains Population of Woodland Caribou (Rangifer tarandus caribou)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of final critical habitat for Rangifer tarandus caribou (Southern Selkirk Mountains population of Woodland Caribou).

  2. Habitat characteristics of prairie-woodland edges at Des Lacs National Wildlife Refuge, North Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Little is known about the vegetation structure and composition of prairie-woodland transition areas at Des Lacs National Wildlife Refuge (DLNWR) in northwestern...

  3. 75 FR 49524 - Woodland Mills Corporation, Mill Spring, NC; Notice of Affirmative Determination Regarding...

    Science.gov (United States)

    2010-08-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Woodland Mills Corporation, Mill Spring, NC; Notice of Affirmative Determination Regarding Application for Reconsideration By application dated July 22, 2010,...

  4. 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.

  5. 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.

  6. Feeding site selection by woodland caribou in north-central British Columbia

    Directory of Open Access Journals (Sweden)

    Chris J. Johnson

    2000-04-01

    Full Text Available We examined the foraging habits of the northern woodland caribou ecotype {Rangifer tarandus caribou at the scale of the individual feeding site. Field data were collected in north-central British Columbia over two winters (Dec 1996-Apr 1998. We trailed caribou and measured vegetation characteristics (species composition and percent cover, snow conditions (depth, density, and hardness, and canopy closure at terrestrial and arboreal feeding sites, and at random sites where feeding had not occurred. Logistic regression was used to determine the attributes of feeding sites that were important to predicting fine scale habitat selection in forested and alpine areas. In the forest, caribou selected feeding sites that had a greater percent cover of Cladina mitis and Cladonia spp, lower snow depths, and a lower percentage of debris and moss. Biomass of Bryoria spp. at the 1-2 m stratum above the snow significantly contributed to predicting what trees caribou chose as arboreal feeding sites. In the alpine, caribou selected feeding sites with a greater percent cover of Cladina mitis, Cladina rangiferina, Cetraria cucullata, Cetraria nivalis, Thamnolia spp., and Stereocaulon alpinum as well as lower snow depths.

  7. 1100 years of human impact on woodland and soils in Kjarardalur, West Iceland

    Science.gov (United States)

    Gísladóttir, Guðrún; Erlendsson, Egill; Lal, Rattan

    2013-04-01

    further soil degradation. The property where sustainable land use had been adopted preserved woodland cover and maintained greater soil quality than elsewhere in the valley, where thresholds of ecosystem resilience were crossed. Unsustainable land use over 1100 years caused vegetation denudation that accelerated soil erosion, with attendant redistribution of soil over the landscape, and decline in its quality. Vegetated areas became important sinks for wind-transported soils, as evidenced by increase in deposition rate and higher bulk density. This led to an increase in susceptibility to soil erosion, and decline in SOC content. Despite decrease in SOC content, the high sedimentation rate and elevated bulk weight resulted in higher SOC sequestration at these sites, even though soil quality declined. The potential soil C sequestration in adjacent sparsely or devegetated soils were highly impaired and along with soil mass losses these areas became sources of anthropogenic CO2.

  8. Dynamics of Sudanian savanna-woodland ecosystem in response to disturbances

    OpenAIRE

    Savadogo, Patrice

    2007-01-01

    Grazing, fire and selective tree cutting are major disturbances shaping species diversity and productivity in savanna-woodland ecosystems. Their effects, however, are highly variable and poorly understood. Structural and functional responses of the Sudanian savanna-woodland ecosystem to such disturbances were investigated, with particular emphasis on the herbaceous vegetation. Fuel and fire behaviour were characterized in relation to grazing, dominant grass type and wind direction. The result...

  9. The impact of broadleaved woodland on water resources in lowland UK: I. Soil water changes below beech woodland and grass on chalk sites in Hampshire

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available The possible effects of broadleaved woodland on recharge to the UK Chalk aquifer have led to a study of evaporation and transpiration from beech woodland (Black Wood and pasture (Bridgets Farm, growing in shallow soils above chalk in Hampshire. Eddy correlation measurements of energy balance components above both the forest and the grassland enabled calculation of latent heat flux (evaporation and transpiration as a residual. Comparative measurements of soil water content and soil water potential in 9 m profiles under both forest and grassland found changes in soil water content down to 6 m at both sites; however, the soil water potential measurements showed upward movement of water only above a depth of about 2 m. Below this depth, water continued to drain and the soil water potential measurements showed downward movement of water at both sites, notwithstanding significant negative soil water potentials in the chalk and soil above. Seasonal differences occur in the soil water content profiles under broadleaved woodland and grass. Before the woodland foliage emerges, greater drying beneath the grassland is offset in late spring and early summer by increased drying under the forest. Yet, when the change in soil water profiles is at a maximum, in late summer, the profiles below woodland and grass are very similar. A comparison of soil water balances for Black Wood and Bridgets Farm using changes in soil water contents, local rainfall and evaporation measured by the energy balance approach allowed drainage to be calculated at each site. Although seasonal differences occurred, the difference in cumulative drainage below broadleaved woodland and grass was small.

  10. Carbon storage in degraded cork oak (Quercus suber forests on flat lowlands in Morocco

    Directory of Open Access Journals (Sweden)

    Oubrahim H

    2016-02-01

    Full Text Available The present study aims to quantify the carbon stored in a degraded cork oak (Quercus suber L. ecosystem in the north west of Morocco, in view of potential management implications. To this end, carbon stocks were evaluated in the first 100 cm of the soil, the cork oak trees, and the understorey species (both above- and belowground. Results show that the total carbon stocks in the cork oak ecosystem ranges from 65 to 237 Mg ha-1 with a mean value of 121 Mg ha-1. The first 100 cm of the soil (including the forest floor represents the largest carbon pool (~51% of the total organic carbon of the ecosystem. Tree biomass (above- and belowground tissues of cork oak represents the second largest pool (47%, whereas the contribution of the understorey is less than 2%. Within the first 100 cm of the soil, over 87% of all the soil organic carbon is situated in the first 40 cm of the soil depth. The amount of carbon stored here ranges from 30 to 110 Mg ha-1and these organic carbon stocks vary considerably with the stand basal area of the cork oak (R2 = 0.82. In practice, the carbon stocks of the different pools considered are strongly correlated with the stand density of the cork oak stands. In the semi-arid forest ecosystems of our study, management prescriptions aiming at increasing the standing biomass of the cork oak should thus considerably contribute, both directly through tree biomass and indirectly through increased soil organic matter, to efficient carbon sequestration.

  11. Potential for Ammonia Recapture by Farm Woodlands: Design and Application of a New Experimental Facility

    Directory of Open Access Journals (Sweden)

    Mark R. Theobald

    2001-01-01

    Full Text Available There has been increasing pressure on farmers in Europe to reduce the emissions of ammonia from their land. Due to the current financial climate in which farmers have to operate, it is important to identify ammonia control measures that can be adopted with minimum cost. The planting of trees around farmland and buildings has been identified as a potentially effective and low-cost measure to enhance ammonia recapture at a farm level and reduce long-range atmospheric transport. This work assesses experimentally what fraction of ammonia farm woodlands could potentially remove from the atmosphere. We constructed an experimental facility in southern Scotland to simulate a woodland shelterbelt planted in proximity to a small poultry unit. By measuring horizontal and vertical ammonia concentration profiles within the woodland, and comparing this to the concentration of an inert tracer (SF6 we estimate the depletion of ammonia due to dry deposition to the woodland canopy. Together with measurements of mean ammonia concentrations and throughfall fluxes of nitrogen, this information is used to provide a first estimate of the fraction of emitted ammonia that is recaptured by the woodland canopy. Analysis of these data give a lower limit of recapture of emitted ammonia, at the experimental facility, of 3%. By careful design of shelterbelt woodlands this figure could be significantly higher.

  12. Oak Ridge TNS Program: system description manual

    Energy Technology Data Exchange (ETDEWEB)

    Reid, R.L.; Becraft, W.R.; Brown, T.G.; Peng, Y.K.M.; Sardella, C.; Shannon, T.E.; Steiner, D.; Wells, W.M.; Wiseman, G.W.

    1979-05-01

    This document provides a systems description of the Reference Design for The Next Step (TNS) evolved at Oak Ridge National Laboratory (ORNL) during FY 1978. The description is presented on the basis of 24 individual device and facility systems. Additional information on these systems, the Reference Design, and the FY 1978 Oak Ridge TNS activities can be found in the associated technical memoranda, ORNL/TM-6720 and ORNL/TM-6722--ORNL/TM-6733.

  13. Ecological effects of lead mining on Ozark streams: In-situ toxicity to woodland crayfish (Orconectes hylas)

    Science.gov (United States)

    Allert, A.L.; Fairchild, J.F.; DiStefano, R.J.; Schmitt, C.J.; Brumbaugh, W.G.; Besser, J.M.

    2009-01-01

    The Viburnum Trend mining district in southeast Missouri, USA is one of the largest producers of lead-zinc ore in the world. Previous stream surveys found evidence of increased metal exposure and reduced population densities of crayfish immediately downstream of mining sites. We conducted an in-situ 28-d exposure to assess toxicity of mining-derived metals to the woodland crayfish (Orconectes hylas). Crayfish survival and biomass were significantly lower at mining sites than at reference and downstream sites. Metal concentrations in water, detritus, macroinvertebrates, fish, and crayfish were significantly higher at mining sites, and were negatively correlated with caged crayfish survival. These results support previous field and laboratory studies that showed mining-derived metals negatively affect O. hylas populations in streams draining the Viburnum Trend, and that in-situ toxicity testing was a valuable tool for assessing the impacts of mining on crayfish populations.

  14. Efficiency of sample-based indices for spatial pattern recognition of wild pistachio (Pistacia atlantica) trees in semi-arid woodlands

    Institute of Scientific and Technical Information of China (English)

    Yousef Erfanifard; Joachim Saborowski; Kerstin Wiegand; Katrin M Meyer

    2016-01-01

    The efficiency of sample-based indices pro-posed to quantify the spatial distribution of trees is influ-enced by the structure of tree stands, environmental heterogeneity and degree of aggregation. We evaluated 10 commonly used distance-based and 10 density-based indices using two structurally different stands of wild pis-tachio trees in the Zagros woodlands, Iran, to assess the reliability of each in revealing stand structure in wood-lands. All trees were completely stem-mapped in a nearly pure (40 ha) and a mixed (45 ha) stand. First, the inho-mogeneous pair correlation function [g(r)] and the Clark–Evans index (CEI) were used as references to reveal the true spatial arrangement of all trees in these stands. The sampled data were then evaluated using the 20 indices. Sampling was undertaken in a grid based on a square lattice using square plots (30 m 9 30 m) and nearest neighbor distances at the sample points. The g(r) and CEI statistics showed that the wild pistachio trees were aggregated in both stands, although the degree of aggregation was markedly higher in the pure stand. Three distance-and six density-based indices statistically verified that the wild pistachio trees were aggregated in both stands. The dis-tance-based Hines and Hines statistic (ht) and the density-based standardised Morisita (Ip), patchiness (IP) and Cassie (CA) indices revealed aggregation of the trees in the two structurally different stands in the Zagros woodlands and the higher clumping in the pure stand, whereas the other indices were not sensitive enough.

  15. 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

  16. 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.

  17. Comparison of oak and sugar maple distribution and regeneration in central Illinois upland oak forests

    Science.gov (United States)

    Peter J. Frey; Scott J. Meiners

    2014-01-01

    Changes in disturbance frequencies, habitat fragmentation, and other biotic pressures are allowing sugar maple (Acer saccharum) to displace oak (Quercus spp.) in the upland forest understory. The displacement of oaks by sugar maples represents a major management concern throughout the region. We collected seedling microhabitat data...

  18. Reactive nitrogen oxides and ozone above a taiga woodland

    Science.gov (United States)

    Bakwin, Peter S.; Jacob, Daniel J.; Wofsy, Steven C.; Munger, J. William; Daube, Bruce C.; Bradshaw, John D.; Sandholm, Scott T.; Talbot, Robert W.; Singh, Hanwant B.; Gregory, Gerald L.; Blake, Donald R.

    1994-01-01

    Measurements of reactive nitrogen oxides (NOx and NOy) and ozone (O3) were made in the planetary boundary layer (PBL) above a taiga woodland in northern Quebec, Canada, during June-August, 1990, as part of NASA Artie Boundary Layer Expedition (ABLE) 3B. Levels of nitrogen oxides and O3 were strongly modulated by the synoptic scale meteorology that brought air from various source regions to the site. Industrial pollution from the Great Lakes region of the U.S. and Canada appears to be a major source for periodic elevation of NOx, NOy and O3. We find that NO/NO2 ratios at this site at midday were approximately 50% those expected from a simple photochemical steady state between NOx and O3, in contrast to our earlier results from the ABLE 3A tundra site. The difference between the taiga and tundra sites is likely due to much larger emissions of biogenic hydrocarbons (particularly isoprene) from the taiga vegetation. Hydrocarbon photooxidation leads to relatively rapid production of peroxy radicals, which convert NO to NO2, at the taiga site. Ratios of NOx to NOy were typically 2-3 times higher in the PBL during ABLE 3B than during ABLE 3 A. This is probably the result of high PAN levels and suppressed formation of HNO3 from NO2 due to high levels of biogenic hydrocarbons at the ABLE 3B site.

  19. Social complexity and the bow in the Eastern Woodlands.

    Science.gov (United States)

    Blitz, John H; Porth, Erik S

    2013-01-01

    Bingham and Souza have presented an evolutionary theory that specifies a causal relationship between the advent of powerful projectile weapons such as the bow and radical rearrangements in social relations and histories. They propose that the acquisition of weapons that permitted humans to kill at ever-increasing distances provided the coercive means to suppress conflicts of interest among nonkin, self-interested individuals in social groups, thus paving the way for greater social complexity. An unprecedented reduction in projectile point size identifies the arrival of the bow ca. A.D. 300 in the Eastern Woodlands of North America, which initiated a causal chain of cultural changes. In the Midwest, the bow, combined with food production, precipitated the decline of Hopewell by conferring household autonomy and dispersal, which at first suppressed social complexity, but later created conditions favorable to maize intensification. In the lower Southeast, where food production was unimportant, populations aggregated at concentrated wild-food sources, and the bow did not confer household autonomy. The relationship between the bow and social complexity varied under different environmental, social, and historical conditions.

  20. Little Smoky Woodland Caribou Calf Survival Enhancement Project

    Directory of Open Access Journals (Sweden)

    Kirkby G. Smith

    2011-09-01

    Full Text Available The Little Smoky woodland caribou (Rangifer tarandus herd is a boreal ecotype located in west central Alberta, Canada. This herd has declined steadily over the past decade and is currently thought to number approximately 80 animals. Factors contributing to the herds' decline appear related to elevated predator-caused mortality rates resulting from industrial caused landscape change. At current rates of decline, the herd is at risk of extirpation. A calf survival enhancement project was initiated in the first half of 2006 as a means of enhancing recruitment while other longer-term approaches were implemented. A total of 10 pregnant females were captured in early March and held in captivity until all calves were at least 3 weeks old. Before release, calves were radiocollared with expandable drop-off collars. Following release, survival of mother and offspring were tracked at intervals until the fall rut. Survival of penned calves was compared to "wild-born" calves at heel of non captive radiocollared females. This approach is compared to other techniques designed to increase recruitment in caribou.

  1. Woodland caribou range occupancy in northwestern Ontario: past and present

    Directory of Open Access Journals (Sweden)

    G.D. Racey

    2000-04-01

    Full Text Available A zone of continuous woodland caribou (Rangifer tarandus caribou distribution is defined for northwestern Ontario. This zone establishes a benchmark for measuring the success of future management of habitat and conservation of populations. Inventory of key winter, summer and calving habitats reaffirms the concept of a dynamic mosaic of habitat tracts that supports caribou across the landscape. The historical range recession leading to this current distribution has been associated with resource development, fire and hunting activities over the past 150 years, and numerous attempts at conservation over the last 70 years. The decline was apparently phased according to several periods of development activity: i early exploitation in the early to mid-1800s; ii isolation and extirpation of southern populations due to rapid changes in forest use and access between 1890 and 1930; and iii further loss of the southernmost herds due to forest harvesting of previously inaccessible areas since the 1950s. Lessons learned from history support current conservation measures to manage caribou across broad landscapes, protect southern herds, maintain caribou habitat as part of continuous range, maintain large contiguous tracts of older forest and ensure connectivity between habitat components.

  2. The development of an aquatic spill model for the White Oak Creek watershed, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.O.

    1996-05-01

    This study develops an aquatic spill model applicable to the White Oak Creek watershed draining the Oak Ridge National Laboratory. Hazardous, toxic, and radioactive chemicals are handled and stored on the laboratory reservation. An accidental spill into the White Oak Creek watershed could contaminate downstream water supplies if insufficient dilution did not occur. White Oak Creek empties into the Clinch River, which flows into the Tennessee River. Both rivers serve as municipal water supplies. The aquatic spill model provides estimates of the dilution at sequential downstream locations along White Oak creek and the Clinch River after an accidental spill of a liquid containing a radioactively decaying constituent. The location of the spill on the laboratory is arbitrary, while hydrologic conditions range from drought to extreme flood are simulated. The aquatic spill model provides quantitative estimates with which to assess water quality downstream from the site of the accidental spill, allowing an informed decision to be made whether to perform mitigating measures so that the integrity of affected water supplies is not jeopardized.

  3. 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.

  4. Taxonomic status of Woodland's enigmatic tapeworms (Cestoda: Proteocephalidea) from Amazonian catfishes: back to museum collections.

    Science.gov (United States)

    de Chambrier, Alain; Scholz, Tomáš; Kuchta, Roman

    2014-01-01

    Poorly known proteocephalidean cestodes of peculiar morphology, described by Woodland (1934) from pimelodid catfishes in Amazonia, Brazil, were studied. Re-examination of their type-specimens and evaluation of newly-collected material from Brazil and Peru made it possible to clarify their taxonomic status. Brayela karuatayi (Woodland, 1934), the type-species of the monotypic Brayela Rego, 1984, which has never been recorded since its original description, is redescribed and its scolex morphology, which has been misinterpreted in the original description, was studied using scanning electron microscopy (SEM). The actual definitive host of B. karuatayi is not a species of Glanidium Lütken (Auchenipteridae), but coroatá, Platynematichthys notatus (Jardine) (Pimelodidae). Peru is a new geographical record for B. karuatayi. The definitive host of other two proteocephalidean cestodes, Megathylacus jandia Woodland, 1934 and Proteocephalus jandia Woodland, 1934, is not a species of Rhamdia Bleeker (family Heptapteridae), but the pimelodid Zungaro zungaro (Humboldt) [syn. Paulicea luetkeni (Steindachner)]. Proteocephalus jandia is in fact conspecific with Travassiella avitellina Rego & Pavanelli, 1987, type-species of Travassiella Rego & Pavanelli, 1987. As a result, a new combination, Travassiella jandia (Woodland, 1934), is proposed. Megathylacus jandia Woodland, 1934 is considered conspecific with M. brooksi Rego & Pavanelli, 1985 described from the congeneric host [Zungaro jahu (Ihering)] from the Paraná River in Brazil; the latter species becomes its new junior synonym. The validity of M. travassosi Pavanelli & Rego, 1992, a parasite of Pseudoplatystoma corruscans (Spix & Agassiz) in the Paraná River basin in Brazil, is confirmed by a study of its type- and voucher specimens. The present account provides strong arguments to always study museum specimens in taxonomic studies; it also represents an evidence of the importance of depositing types and vouchers in

  5. Effects of restoring oak savannas on bird communities and populations.

    Science.gov (United States)

    Brawn, Jeffrey D

    2006-04-01

    Efforts to restore and maintain oak savannas in North America, with emphasis on the use of prescribed fire, have become common. Little is known, however about how restoration affects animal populations, especially those of birds. I compared the breeding densities, community structure, and reproductive success of birds in oak savannas maintained by prescribed fire (12 sites) with those in closed-canopy forests (13 sites). All sampling was conducted in Illinois (U.S.A.). Of the 31 bird species analyzed, 12 were more common in savannas, 14 were not affected by habitat structure, and 5 were more common in forest habitat. The species favored by disturbance and restoration included Northern Bobwhites (Colinus virginianus), Mourning Doves (Zenaida macroura), Red-headed Woodpeckers (Melanerpes erythrocephalus), Indigo Buntings (Passerina cyanea), and Baltimore Orioles (Icterus galbula). Those more common in closed-canopy forest included Ovenbirds (Seiurus aurocapilla) and Wood Thrushes (Hylocichla mustelina). Few species were unique to one type of habitat, but overall avian community structure in oak savannas and closed-canopy forests was generally distinctive. Estimates of nesting success (derived from 785 nests) revealed that 6 of the 13 species considered experienced greater productivity in the savanna habitat. Rates of brood parasitism were unaffected by restoration and habitat structure. Within savannas, tract size had little effect on breeding abundances and reproductive success. My results illustrate that restoration techniques can significantly affect the ecology of constituent animal populations and communities and have key implications regarding avian conservation and the management of forest habitat in fragmented landscapes. Small patches of forest habitat that regularly function as population sinks may offer far better prospects for birds if they are subjected to disturbance and ecosystem restoration.

  6. Canopy arthropods community within and among oak species in central Mexico

    Institute of Scientific and Technical Information of China (English)

    Efraín TOVAR-SANCHEZ

    2009-01-01

    Quercus rugosa and Q.laurina are species that presents a wide geographical distribution range in temperate forests of Mexico. Oak canopies contain a considerable portion of arthropod diversity and the arthropods fauna fulfill a wide variety of ecological roles. We examined the effect of oak species and seasonal changes on some community structure parameters (diversity, composition, similarity, biomass, rare species, and density of arthropod fauna) of canopy arthropods. In total, 40 oak canopies were fogged during rainy and dry season. A total of 614 identified arthropod morphospecies were recognized belonging to 22 orders associated with tree canopies. A separation of host tree species during both seasons, suggesting a different community structure on host plants species was demonstrated by the principal component analyses (PCA), therefore, differences between oak species results in phenotypes that structure the composition of the arthropod community. Q.laurina registered the highest densities, diversity index and number of rare species in comparison with Q.rugosa. While arthropod biomass showed an inverse pattern. Trees more close to one another (spatial distance) register a more similar canopy arthropod fauna. This study suggests that the trees of Q.laurina could act as a center of biodiversity by the accumulation of arthropod fauna with a considerable number of rare species, which presents wide ecological roles or is involved in critical processes that maintain forest ecosystems[Current Zoology 55(2):132-144,2009].

  7. The social value of carbon sequestered in Great Britain's woodlands

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, Julii; Bateman, Ian J.; Lovett, Andrew A. [Centre for Social and Economic Research on the Global Environment, School of Environmental Sciences, University of East Anglia, Norwich, Norfolk NR4 7TJ (United Kingdom)

    2009-02-15

    The economic value of carbon storage associated with British woodland is calculated. Models were developed to estimate C flux associated with live trees, forest floor litter, soils, wood products, harvest, fossil fuel used in manufacturing and C displacement from biofuels and products for representative British plantation species: Sitka spruce (Picea sitchensis) and beech (Fagus sylvatica). Map databases of publicly and privately owned woodlands were compiled for Great Britain. Carbon flux was determined for individual woodland sites, and monetised using candidate parameters for the social discount rate (1, 3, 3.5 or 5%) and social value of carbon (USD109.5, USD1, USD10 or USD17.10/t). A conventional discount function was applied. Final results are expressed as Net Present Values, for the base year 2001, with discounting commencing in 2002. The minimum suggested NPV (discount rate = 3% and social value of carbon = USD1) of GB woodlands already existing in 2001 is USD82 million, with a further USD72 million that might be added by future afforestation. These figures rise dramatically if a discount rate of 1% and social value of sequestered carbon = USD109.5/t are assumed. The calculated total value of C stored in British woodland depends significantly on parameter assumptions, especially about appropriate discount rate and social value of sequestered carbon. (author)

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

    Science.gov (United States)

    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.

  9. Hydrology and ecology of pinyon-juniper woodlands: Conceptual framework and field studies

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, B.P.; Breshears, D.D.

    1994-09-01

    Pinyon-juniper woodlands represent an important ecosystem in the semiarid western United States. Concern over the sustainability of, and management approaches for, these woodlands is increasing. As in other semiarid environments, water dynamics and vegetation patterns in pinyon-juniper woodlands are highly interrelated. An understanding of these relationships can aid in evaluating various management strategies. In this paper we describe a conceptual framework designed to increase our understanding of water and vegetation in pinyon-juniper woodlands. The framework comprises five different scales, at each of which the landscape is divided into {open_quotes}functional units{close_quotes} on the basis of hydrologic characteristics. The hydrologic behavior of each unit and the connections between units are being evaluated using an extensive network of hydrological and ecological field studies on the Pajarito Plateau in northern New Mexico. Data from these studies, coupled with application of the conceptual model, have led to the development of a number of hypotheses concerning the interrelationships of water and vegetation in pinyon-juniper woodlands.

  10. Revision of Wenyonia Woodland, 1923 (Cestoda: Caryophyllidea) from catfishes (Siluriformes) in Africa.

    Science.gov (United States)

    Schaeffner, Bjoern C; Jirků, Miloslav; Mahmoud, Zuheir N; Scholz, Tomáš

    2011-06-01

    Tapeworms of the genus Wenyonia Woodland, 1923 (Caryophyllidea: Caryophyllaeidae), parasites of catfishes in Africa, are revised. This revision is based on material from large-scale sampling, in the Democratic Republic of the Congo, Kenya, Senegal and the Sudan between 2006 and 2009, and the examination of all of the type-specimens available. The following six species are considered valid and their redescriptions are provided: Wenyonia virilis Woodland, 1923 (type-species; new synonym W. kainjii Ukoli, 1972); W. acuminata Woodland, 1923; W. longicauda Woodland, 1937; W. minuta Woodland, 1923 (new synonym W. mcconnelli Ukoli, 1972); W. synodontis Ukoli, 1972; and W. youdeoweii Ukoli, 1972. A key to the identification of Wenyonia spp. is provided and numerous new hosts and geographical records are reported. A comparative phylogenetic analysis of partial sequences of the 28S rRNA gene of four species divided the monophyletic genus into two lineages, one represented by W. acuminata and W. minuta and another one composed of W. virilis and W. youdeoweii.

  11. Ecosystem services from southern African woodlands and their future under global change.

    Science.gov (United States)

    Ryan, Casey M; Pritchard, Rose; McNicol, Iain; Owen, Matthew; Fisher, Janet A; Lehmann, Caroline

    2016-09-19

    Miombo and mopane woodlands are the dominant land cover in southern Africa. Ecosystem services from these woodlands support the livelihoods of 100 M rural people and 50 M urban dwellers, and others beyond the region. Provisioning services contribute $9 ± 2 billion yr(-1) to rural livelihoods; 76% of energy used in the region is derived from woodlands; and traded woodfuels have an annual value of $780 M. Woodlands support much of the region's agriculture through transfers of nutrients to fields and shifting cultivation. Woodlands store 18-24 PgC carbon, and harbour a unique and diverse flora and fauna that provides spiritual succour and attracts tourists. Longstanding processes that will impact service provision are the expansion of croplands (0.1 M km(2); 2000-2014), harvesting of woodfuels (93 M tonnes yr(-1)) and changing access arrangements. Novel, exogenous changes include large-scale land acquisitions (0.07 M km(2); 2000-2015), climate change and rising CO2 The net ecological response to these changes is poorly constrained, as they act in different directions, and differentially on trees and grasses, leading to uncertainty in future service provision. Land-use change and socio-political dynamics are likely to be dominant forces of change in the short term, but important land-use dynamics remain unquantified.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'. © 2016 The Authors.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Ecosystem services from southern African woodlands and their future under global change

    Science.gov (United States)

    Pritchard, Rose; McNicol, Iain; Owen, Matthew; Fisher, Janet A.; Lehmann, Caroline

    2016-01-01

    Miombo and mopane woodlands are the dominant land cover in southern Africa. Ecosystem services from these woodlands support the livelihoods of 100 M rural people and 50 M urban dwellers, and others beyond the region. Provisioning services contribute $9 ± 2 billion yr−1 to rural livelihoods; 76% of energy used in the region is derived from woodlands; and traded woodfuels have an annual value of $780 M. Woodlands support much of the region's agriculture through transfers of nutrients to fields and shifting cultivation. Woodlands store 18–24 PgC carbon, and harbour a unique and diverse flora and fauna that provides spiritual succour and attracts tourists. Longstanding processes that will impact service provision are the expansion of croplands (0.1 M km2; 2000–2014), harvesting of woodfuels (93 M tonnes yr−1) and changing access arrangements. Novel, exogenous changes include large-scale land acquisitions (0.07 M km2; 2000–2015), climate change and rising CO2. The net ecological response to these changes is poorly constrained, as they act in different directions, and differentially on trees and grasses, leading to uncertainty in future service provision. Land-use change and socio-political dynamics are likely to be dominant forces of change in the short term, but important land-use dynamics remain unquantified. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’. PMID:27502377

  14. BIFoR FACE: A ten-year Free-Air Carbon Dioxide Enrichment (FACE) Experiment in Old Growth Deciduous English Woodland

    Science.gov (United States)

    Thomas, R. M.; MacKenzie, A. R.; Ellsworth, D.; Hemming, D.; Crous, K.; Pope, F.; Blaen, P.; Poynter, A.; Hamilton, L.; Blenkhorn, D.; Jarvis-Rouse, F.

    2015-12-01

    The Birmingham Institute of Forest research (BIFoR) will perform fundamental physical, biological, ecological, social and cultural research of direct relevance to forested landscapes worldwide. A core platform for BIFoR to study the ten-year response of a mature temperate deciduous forest ecosystem to against a large step-change in atmospheric [CO2] is the BIFoR Free-Air Carbon Dioxide Enrichment (FACE) experiment. BIFoR FACE is being established in Mill Haft, a mature (~150 year-old) oak (Quercus robur) and hazel (Corylus avellana) coppice-with-standards woodland in central England. The facility will enable elevated CO2 (eCO2) treatments to be introduced in 30 m diameter rings (3 treatment and 6 control plots), commencing in spring 2016. Under eCO2 conditions primary research questions will investigate carbon uptake and storage, corresponding nutrient limitations, and biodiversity and ecosystem responses. As well as describing the facility and experimental design, we present baseline data collected throughout 2015, prior to fumigation. These data include: biophysical tree properties; atmospheric CO2/H2O fluxes; airborne and ground laser scatterometry; leaf area index; geophysical survey data; phenology camera derivatives; soil and water chemical and physical properties; and invertebrate surveys. Data from an intensive campaign conducted during august 2015 are also shown, including in- and above- canopy characterisation of biogenic VOCs using a Proton Transfer Reaction Mass Spectrometer, aerosol loading including bioaerosols, and enhanced atmospheric chemistry. Further campaign results are presented from leaf level photosynthetic carbon-dioxide response curve (A/Ci) performed at different canopy heights on oak trees, and on the dominant understory species - hazel and sycamore (Acer pseudoplatinus) across the site. BIFoR FACE is an exciting new international facility for forest science - ideas for collaborations are encouraged. Please see http

  15. Phylogeographical Variation of Chloroplast DNA in Cork Oak (Quercus suber)

    OpenAIRE

    Lumaret, Roselyne; TRYPHON-DIONNET, MATHIEU; MICHAUD, HENRI; SANUY, AURÉLIE; IPOTESI, EMILIE; Born, Céline; MIR, CÉLINE

    2005-01-01

    • Background and Aims In the last decades, the geographical location of the centre of origin of Quercus suber (cork oak), a strictly western Mediterranean oak species, has been the subject of controversy.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. 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

  18. 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.

  19. Ecohydrological and Socioeconomic Relationships in Disturbed Woodland Ecosystems of the Western U.S.

    Science.gov (United States)

    Ochoa, C. G.; Guldan, S. J.; Tidwell, V. C.; Deboodt, T.

    2016-12-01

    In many areas of the western U.S., the significant encroachment of juniper (Juniperus spp.) into grassland and sage steppe ecosystems has disrupted important ecological and hydrological functions. Striking landscape changes attributed to high levels of encroachment have raised considerable concerns about the negative impacts of juniper expansion on multiple ecosystem functions and services. Juniper encroachment can limit the growth of understory vegetation, reduce biodiversity, modify hydrologic processes, and alter soil nutrient cycling. Many producers, agency staff, and scientists have indicated the need for an integrated approach to manage juniper woodlands for multiple ecosystem benefits (e.g., water, forage, and wildlife habitat). Using a systems approach, we are investigating biophysical and socioeconomic linkages in very dense juniper-dominated landscapes of Oregon and New Mexico. Ongoing study results in the biophysical component in Oregon show that increases in perennial grass cover are positively correlated with soil moisture, whereas increases in juniper cover are negatively correlated. Winter precipitation infiltrates relatively rapidly through the soil profile and into the aquifer. Greater springflow and runoff rates are observed in a watershed where juniper was removed (90%). Shallow groundwater response observed in watershed and valley monitoring wells show there are temporary hydrologic connections between upland and lowland locations during the winter precipitation season. Study findings indicate that in similar, highly encroached landscapes, reducing juniper tree density may improve overall watershed function and enhance ecosystems services such as forage and water provisioning. In the socioeconomic component, we are in constant communication with different stakeholders to enhance our understanding of current management practices and perceptions related to juniper control. Also, we are gathering economic data from secondary sources that will

  20. Dynamics of the leaf-litter arthropod fauna following fire in a neotropical woodland savanna.

    Directory of Open Access Journals (Sweden)

    Heraldo L Vasconcelos

    Full Text Available Fire is an important agent of disturbance in tropical savannas, but relatively few studies have analyzed how soil-and-litter dwelling arthropods respond to fire disturbance despite the critical role these organisms play in nutrient cycling and other biogeochemical processes. Following the incursion of a fire into a woodland savanna ecological reserve in Central Brazil, we monitored the dynamics of litter-arthropod populations for nearly two years in one burned and one unburned area of the reserve. We also performed a reciprocal transplant experiment to determine the effects of fire and litter type on the dynamics of litter colonization by arthropods. Overall arthropod abundance, the abundance of individual taxa, the richness of taxonomic groups, and the species richness of individual taxa (Formiciade were lower in the burned site. However, both the ordinal-level composition of the litter arthropod fauna and the species-level composition of the litter ant fauna were not dramatically different in the burned and unburned sites. There is evidence that seasonality of rainfall interacts with fire, as differences in arthropod abundance and diversity were more pronounced in the dry than in the wet season. For many taxa the differences in abundance between burned and unburned sites were maintained even when controlling for litter availability and quality. In contrast, differences in abundance for Collembola, Formicidae, and Thysanoptera were only detected in the unmanipulated samples, which had a lower amount of litter in the burned than in the unburned site throughout most of our study period. Together these results suggest that arthropod density declines in fire-disturbed areas as a result of direct mortality, diminished resources (i.e., reduced litter cover and less favorable microclimate (i.e., increased litter desiccation due to reduction in tree cover. Although these effects were transitory, there is evidence that the increasingly prevalent fire

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Managing California black oak for tribal ecocultural restoration

    Science.gov (United States)

    Jonathan W. Long; Ron W. Goode; Raymond J. Gutteriez; Jessica J. Lackey; M. Kat Anderson

    2017-01-01

    Many tribes in California and Oregon value California black oak (Quercus kelloggii) as a traditional source of food and other values. Over centuries or millennia, Native Americans learned that they could enhance production of desired resources by regularly igniting low-intensity surface fires in stands of black oak. Although black oak is likely to...

  3. 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...

  4. Woodland: Geographical and Forest Inventory Indications and Criteria (Continuation. Beginning in N. 1, 2014

    Directory of Open Access Journals (Sweden)

    R. A. Ziganshin

    2014-04-01

    Full Text Available The definition of woodland is discussed. The structure and dynamics of forestland are considered on the example of the Tankhoisky forestry district in the South Baikal region. In particular, we consider the representation in the woodland series of forest types, forest inventory compartments by series of forest types, the types of tree species' mixing in the birch forest types. The distribution of all forest types by the productivity classes is done. The age dynamics of tree species' composition and tree stand timber stock is considered for the most representative forest types. The characteristics of natural regeneration in this woodland is presented. The features of forest management and forestry regime for the first group of mountain forests in the Baikal lake basin are discussed. In conclusion the geographical and forest inventory features, criteria and materials describing the forest are enumerated.

  5. 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.

  6. Management Tools and Potential of Dry Miombo Woodland in Carbon Cycling

    DEFF Research Database (Denmark)

    Mwakalukwa, Ezekiel Edward

    , this thesis aims to develop management tools and generate information that will enhance our understanding of the actual and potential contribution of dry Miombo woodlands in carbon cycling. This is done through a detailed assessment of floristic composition, structure, species associations and through......Abstract Tools to support sustainable management of dry Miombo woodlands and precise assessment of carbon storage and sequestration potential are in most cases lacking in Tanzania. Accordingly, using Gangalamtumba Village Land Forest Reserve as a case study area located in Iringa region...... in above- and below-ground soil carbon pools. Assuming that other species’ production are equal to B. spiciformis, which is the most dominant species in the study area, the estimated C sequestration potential of the dry Miombo woodlands was found to vary from 0.42 ± 0.03 Mg C ha-1year-1 to 1.39 ± 0.08 Mg C...

  7. 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...

  8. Anchor chaining’s influence on soil hydrology and seeding success in burned piñon-juniper woodlands

    Science.gov (United States)

    Broadcast seeding is one of the most commonly used rehabilitation treatments for the restoration of burned piñon (Pinus ssp.) and juniper (Juniperus spp.) woodlands, but the success rate of this treatment is notoriously low. In piñon-juniper woodlands, post-fire soil water repellency can impair rese...

  9. Indigenous Cultural Self-Representation and Its Internal Critiques: A Case Study of the Woodland Cultural Centre, Canada

    Science.gov (United States)

    Nakamura, Naohiro

    2014-01-01

    This research report discusses Indigenous cultural representation and its internal critiques, based on the case study of an Indigenous-run museum, the Woodland Cultural Centre, in Canada. Since its establishment in 1972, the Woodland Cultural Centre has strived to promote Indigenous culture, especially First Nations art, and has challenged the…

  10. 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

  11. 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....

  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

  13. 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

  14. How oaks respond to water limitation

    Science.gov (United States)

    Michael F. Allen

    2015-01-01

    Oaks are extremely resilient trees. They have persisted since the mid-Cretaceous, with life forms ranging from shrubs to large trees, from evergreen to deciduous. They have two distinct, but critical, adaptations to drought that make this "mesic" taxon adaptable to dry hot environments. First, they form both arbuscular and ectotrophic mycorrhizae, with a high...

  15. Chloroplast DNA variation of northern red oak

    Science.gov (United States)

    Jeanne Romero-Severson; Preston Aldrich; Yi Feng; Weilin Sun; Charles Michler

    2003-01-01

    Chloroplast DNA (cpDNA) variation was examined in 48 northern red oaks at 14 sites representing contrasting glacial histories and age structures within the state of Indiana in the United States. PCR-RFLP of three intergenic regions revealed five haplotypes. Haplotype I was common to seven sites and was the most frequent (17 trees). Haplotype II was common to five sites...

  16. 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.

  17. Consort contact dermatitis due to oak moss.

    Science.gov (United States)

    Held, J L; Ruszkowski, A M; Deleo, V A

    1988-02-01

    An allergic contact dermatitis in a woman was found to be due to oak moss in her husband's after-shave lotion. When routine patch testing reveals a positive reaction, the dermatologist should consider exposure to the antigen not only in the patient but also through contact with the patient's consort.

  18. Oak Ridge Reservation Waste Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.W. [ed.

    1995-02-01

    This report presents the waste management plan for the Oak Ridge Reservation facilities. The primary purpose is to convey what facilities are being used to manage wastes, what forces are acting to change current waste management systems, and what plans are in store for the coming fiscal year.

  19. Seismic hazard evaluation for Department of Energy Oak Ridge Reservations, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, R.K.; Toro, G.F. [Risk Engineering, Inc., Golden, CO (United States); Hunt, R.J. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States). Center for Natural Phenomena Engineering

    1992-09-30

    This study presents the results of an investigation of seismic hazard at the Department of Energy Oak Ridge Reservations (K-25 Site, Oak Ridge National Laboratories, and Oak Ridge Y-12 Plant), located in Oak Ridge, Tennessee. Oak Ridge is located in eastern Tennessee, in an area of moderate to high historical seismicity. Results from two separate seismic hazard analyses are presented. The EPRI/SOG analysis uses the input data and methodology developed by the Electric Power Research Institute, under the sponsorship of several electric utilities, for the evaluation of seismic hazard in the central and eastern United States. The LLNL analysis uses the input data and methodology developed by the Lawrence Livermore National Laboratory for the Nuclear Regulatory Commission. Both the EPRI/SOG and LLNL studies characterize earth-science uncertainty on the causes and characteristics of earthquakes in the central and eastern United States. This is accomplished by considering multiple hypotheses on the locations and parameters of seismic source zones and by considering multiple attenuation functions for the prediction of ground shaking given earthquake size and location. These hypotheses were generated by multiple expert teams and experts. Furthermore, each team and expert was asked to generate multiple hypotheses in order to characterize his own internal uncertainty. The seismic-hazard calculations are performed for all hypotheses. Combining the results from each hypothesis with the weight associated to that hypothesis, one obtains an overall representation of the seismic hazard at the Oak Ridge site and its uncertainty.

  20. 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.

  1. MODELS AND TABLES OF GROWTH OF ARTIFICIAL ORIGIN OAK FORESTS IN THE LOWER VOLGA REGION

    Directory of Open Access Journals (Sweden)

    Panchenko L. A.

    2013-11-01

    Full Text Available The article discusses the function of growth for the simulation of forest indices of individual tree element of the forest. Algorithm calculate tables of growth based on materials by eye-measuring taxation on the basis of patterns of variability of the amount of Room space of sections of stands of oak is proposed. Tables of growth of stands of different density are developed

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  3. The effects of seeding sterile triticale on a native plant community after wildfire in a pinyon pinemountain mahogany woodland

    Science.gov (United States)

    Waitman, B.A.; Draper, T.M.; Esque, T.C.

    2009-01-01

    Post-fire seeding with grasses is a common practice for emergency rehabilitation of burned woodlands. However, most post-seeding monitoring does not address consequences to native flora. In November 2004, the US Forest Service hand-seeded triticale (Triticosecale Wittm. ex A. Camus), a sterile wheatrye hybrid, on a small burned area in the Spring Mountains of southern Nevada, United States. A monitoring project using paired plots was designed to quantify the effects of seeding triticale on density and species richness of native annual and perennial plants, cover of perennial plants, and aboveground production of annual plants. We did not find any effects of triticale seeding on annual plant species or most responses of perennial plants. However, the density of woody perennial seedlings was significantly lower 2 years after triticale was added. Although we found a smaller impact from seeding with exotic grass than other studies, quantifiable costs to native vegetation were observed. We caution against the use of non-native grass for seeding in areas with naturally low perennial recruitment. ?? IAWF 2009.

  4. Water balance and carbon sink strength of an European savannah-type woodland during the drought year 2012

    Science.gov (United States)

    Piayda, A.; Dubbert, M.; Rebmann, C.; Kolle, O.; Costa e Silva, F.; Correia, A.; Pereira, J. S.; Werner, C.; Cuntz, M.

    2013-12-01

    Savannah-type ecosystems account for around 30% of global gross primary production (GPP) and are the second most important biome in terms of global GPP after the tropical forests. A typical savannah-type woodland in Europe (montado) consists of a sparse tree layer and a herbaceous understorey layer, covering an area of 2-2.5 million ha on the Iberian Peninsula. These ecosystems are adapted to regular summer droughts depending on life form (Chamaephyte or Therophyte) and access to different water reservoirs. In the recent past, annual precipitation exhibits a significant decrease in winter and spring as well as of total annual rainfall on the Iberian Peninsula. The objective of this study is to investigate the differences in ecosystem fluxes of a typical European savannah-type cork oak (Quercus suber L.) woodland between the very wet year 2011 and the extreme drought year 2012. We measured CO2 and H2O fluxes of the trees and the understory with two eddy covariance towers above and below the tree canopy, respectively. We also measured auxiliary ecosystem variables such as precipitation, soil temperature Ts and moisture θ, and leaf area index LAI. Precipitation P was 34% higher in 2011 and 39% lower in 2012 than the long-term average. The intra-annual pattern of P shows a severe drought anomaly in winter to early spring 2012 accounting for up to 68% of the total annual P reduction. However, evapotranspiration (ET) only diminished by 15% due to a decrease in canopy conductance gc while vapour pressure deficit stayed almost constant. Thus, annual ET/P fraction increased from 34% to 80%. This left only a very small amount of water for soil moisture replenishing, resulting in only half the soil moisture in spring 2012 compared to the spring 2011. While gc was reduced by 15% in 2012 compared to 2011, annual GPP of the trees was reduced by 28%. We could attribute this by fitting the Farquhar-model of photosynthesis to a further reduction of the maximum carboxylation rate

  5. 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.

  6. 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.

  7. From protege to nurse plant : Establishment of thorny shrubs in grazed temperate woodlands

    NARCIS (Netherlands)

    Smit, Christian; Ruifrok, Jasper Laurens

    2011-01-01

    Question Thorny shrubs play keystone roles in grazed ecosystems by defending non-protected plants against herbivores, but their establishment in grazed ecosystems is poorly understood. Which factors control establishment of recruits of thorny nurse shrubs in grazed temperate woodlands? Location Anci

  8. Soil morphology of canopy and intercanopy sites in a pinon-Juniper woodland

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, D.W.; Wilcox, B.P.; Breshear, D.D. [Los Alamos National Lab., NM (United States)

    1996-11-01

    Pinon-juniper woodlands in the semiarid western USA have expanded as much as fivefold during the last 150 yr, often accompanied by losses of understory vegetation and increasing soil erosion. We conducted this study to determine the differences in soil morphology between canopy and intercanopy locations within a pinon (Pinus edulis Engelm.)-juniper [Juniperus monosperma (Engelm.) Sarg.] woodland with uniform parent material, topography, and climate. The woodland studied, located near Los Alamos, NM, has a mean tree age of 135 yr. We examined soil morphology by augering 135 profiles in a square grid pattern and comparing soils under pinon and juniper canopies with intercanopy soils. Only two of the 17 morphological properties compared showed significant differences. The B horizons make up a slightly greater proportion of total profile thickness in intercanopy soils, and there are higher percentages of coarse fragments in the lower portions of canopy soil profiles. Canopy soils have lower mean pH and higher mean organic C than intercanopy soils. Regression analysis showed that most soil properties did not closely correspond with tree size, but total soil thickness and B horizon thickness are significantly greater under the largest pinon trees, and soil reaction is lower under the largest juniper trees. Our findings suggest that during the period in which pinon-juniper woodlands have been expanding, the trees have had only minor effects on soil morphology. 36 refs., 4 figs., 4 tabs.

  9. Developing a woodland caribou habitat mosaic on the Ogoki-Nakina North Forests of northwestern Ontario

    Directory of Open Access Journals (Sweden)

    I. Armstrong

    1998-03-01

    Full Text Available The Ogoki-North Nakina Forests consist of (10 638 km2 unroaded boreal forest approximately 400 km northeast of Thunder Bay, Ontario (lat 50°- 51°31'N, long 86°30'- 89°W. Woodland caribou (Rangifer tarandus caribou inhabit discrete portions within these forests based on minimal current and past historical data. As part of the Forest Management Planning process, for the period 1997-2097, a woodland caribou habitat mosaic has been developed to coordinate present and future forest management activities with the retention and development of current and future woodland caribou habitat. Several criteria including, past fire history, forest structure, age, species composition, proximity to current road access and location of existing and potential caribou habitat, helped identify and delineate 50 mosaic harvest blocks. Each harvest block will be logged in one of five 20 year periods over a 100 year rotation (1997¬2097. The harvest blocks have been developed to simulate a pattern of past wildfire history in an area that has not been subjected to past forest management activities, while managing for woodland caribou, a locally featured species.

  10. 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.

  11. Managing fire for woodland caribou in Jasper and Banff National Parks

    Directory of Open Access Journals (Sweden)

    Landon Shepherd

    2007-04-01

    Full Text Available Woodland caribou (Rangifer tarandus caribou populations in Jasper (JNP and Banff National Parks (BNP have declined since the 1970s, coincident with reduced fire activity in both parks, relative to historic levels. Some researchers have suggested that long periods without fire may cause habitat deterioration for woodland caribou, primarily by reducing available lichen forage. We examined winter habitat selection by woodland caribou at coarse and fine scales based on GPS-derived telemetry data and used models that included stand origin (decade, topography, and several stand structure variables that are related to time since fire, to explore relationships among caribou, lichen, and fire history. Based on the relationships illustrated by the models, we assessed how fire management could be applied to caribou conservation in JNP and BNP. At a coarse scale, caribou selected old forest (> 75 years in landscapes that have likely experienced less frequent wildfire. While the abundance of Cladonia spp. influenced caribou use at fine scales, a preference for areas with older trees within stands was also significant. We conclude that short-term habitat protection for woodland caribou in JNP and BNP likely requires fire exclusion from caribou range.

  12. From protege to nurse plant : Establishment of thorny shrubs in grazed temperate woodlands

    NARCIS (Netherlands)

    Smit, Christian; Ruifrok, Jasper Laurens

    Question Thorny shrubs play keystone roles in grazed ecosystems by defending non-protected plants against herbivores, but their establishment in grazed ecosystems is poorly understood. Which factors control establishment of recruits of thorny nurse shrubs in grazed temperate woodlands? Location

  13. Mapping East African tropical forests and woodlands : a comparison of classifiers

    NARCIS (Netherlands)

    Nangendo, G.; Skidmore, A.K.; Oosten, van H.

    2007-01-01

    In mapping the forest¿woodland¿savannah mosaic of Budongo Forest Reserve, Uganda, four classification methods were compared, i.e. Maximum Likelihood classifier (MLC), Spectral Angle Mapper (SAM), Maximum Likelihood combined with an Expert System (MaxExpert) and Spectral Angle Mapper combined with an

  14. Phenology and climate relationships in aspen (Populus tremuloides Michx.) forest and woodland communities of southwestern Colorado

    Science.gov (United States)

    Meier, Gretchen A.; Brown, Jesslyn F.; Evelsizer, Ross J.; Vogelmann, James E.

    2014-01-01

    Trembling aspen (Populus tremuloides Michx.) occurs over wide geographical, latitudinal, elevational, and environmental gradients, making it a favorable candidate for a study of phenology and climate relationships. Aspen forests and woodlands provide numerous ecosystem services, such as high primary productivity and biodiversity, retention and storage of environmental variables (precipitation, temperature, snow–water equivalent) that affect the spring and fall phenology of the aspen woodland communities of southwestern Colorado. We assessed the land surface phenology of aspen woodlands using two phenology indices, start of season time (SOST) and end of season time (EOST), from the U.S. Geological Survey (USGS) database of conterminous U.S. phenological indicators over an 11-year time period (2001–2011). These indicators were developed with 250 m resolution remotely sensed data from the Moderate Resolution Imaging Spectroradiometer processed to highlight vegetation response. We compiled data on SOST, EOST, elevation, precipitation, air temperature, and snow water equivalent (SWE) for selected sites having more than 80% cover by aspen woodland communities. In the 11-year time frame of our study, EOST had significant positive correlation with minimum fall temperature and significant negative correlation with fall precipitation. SOST had a significant positive correlation with spring SWE and spring maximum temperature.

  15. Microsite and time since prescribed fire's influence on soil microbiology in a pinyon woodland

    Science.gov (United States)

    Benjamin M. Rau; Robert R. Blank; Tye Morgan

    2008-01-01

    Pinyon-juniper (Pinus monophylla Torr. & Frém.? Juniperus osteosperma Torr.) encroachment into sagebrush grasslands is a continuing problem in the Western United States. Prescribed burning has been suggested to slow woodland encroachment. We examined surface soil microbial community structure using Phospholipid Fatty Acid (PLFA...

  16. 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 m

  17. 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.

  18. Influence of Prescribed Fire on Ecosystem Biomass, Carbon, and Nitrogen in a Pinyon Juniper Woodland

    Science.gov (United States)

    Pinyon and juniper woodland encroachment associated with climate change and land use history in the Great Basin is thought to provide offsets for carbon emissions. However, the largest pools of carbon in arid landscapes are typically found in soils, and aboveground biomass cannot be considered long ...

  19. 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 s

  20. Arbuscular mycorrhizal associations in Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands of Northern Ethiopia.

    NARCIS (Netherlands)

    Emiru Birhane, E.B.; Kuyper, T.W.; Sterck, F.J.; Bongers, F.

    2010-01-01

    This study assessed the arbuscular mycorrhizal (AM) status of Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands in relation to season, management and soil depth in Ethiopia. We studied 43 woody species in 52 plots in three areas. All woody species were colonized by AM fungi,

  1. Woodland salamanders as metrics of forest ecosystem recovery: a case study from California’s redwoods

    Science.gov (United States)

    Hart Welsh; Garth Hodgson

    2013-01-01

    Woodland (Plethodontid) salamanders occur in huge numbers in healthy forests in North America where the abundances of many species vary along successional gradients. Their high numbers and trophic role as predators on shredder and decomposer arthropods influence nutrient and carbon pathways at the leaf litter/soil interface. Their extreme niche conservatism and low...

  2. Ground Spider Guilds and Functional Diversity in Native Pine Woodlands and Eucalyptus Plantations.

    Science.gov (United States)

    Corcuera, Pablo; Valverde, Pedro Luis; Jiménez, María Luisa; Ponce-Mendoza, Alejandro; De la Rosa, Gabriela; Nieto, Gisela

    2016-04-01

    Vegetation structure and floristics have a strong influence on the relative abundance of spider guilds and functional diversity of terrestrial arthropods. Human activities have transformed much of the temperate woodlands. The aim of this study was to test five predictions related to the guild distribution and functional diversity of the ground spider communities of Eucalyptus plantations and native pine woodlands in western Mexico. Spiders were collected every fortnight from September to November from 15 pitfalls positioned in each of the eight sites. We also assessed the cover of grasses, herbs, shrubs, and leaf litter in each site. We found that the abundances of ground hunters and sheet weavers between plantations and pine woodlands were different. Nevertheless, there was not a consistent difference between sites of each of the vegetation types. Most species of ground hunters, sheet web weavers, and many other hunters were associated with litter and the grass cover. Nonetheless, in some cases, species of different families belonging to the same guild responded to different variables. Wolf spiders were related to the grass Aristida stricta Micheaux, 1803, while the species of the other families of ground hunters were associated with leaf litter. One Eucalyptus plantation and one pine woodland had the highest functional diversity of all sites. These sites have a well developed litter and grass cover. Our study suggests that the abundance of litter and a high cover of grasses explain the occurrence of species with different traits, and these habitat components results in a high functional diversity.

  3. Coppice management effects on experimentally established populations of three herbaceous layer woodland species

    NARCIS (Netherlands)

    H van Calster; P. Endels; K. Antonio; K. Verheyen; M. Hermy

    2008-01-01

    Traditional coppice management creates a temporal release of resources. We determined how this affected three herbaceous species (Cardamine pratensis, Primula elatior and Geum urbanum) and if it was suitable for their conservation within woodland given their differing phenologies and habitat affinit

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

    NARCIS (Netherlands)

    Smit, Christian; Verwijmeren, Mart

    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 mi

  5. 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...

  6. 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 nitroge

  7. Biological soil crust response to late season prescribed fire in a Great Basin juniper woodland

    Science.gov (United States)

    Steven D. Warren; Larry L. St.Clair; Jeffrey R. Johansen; Paul Kugrens; L. Scott Baggett; Benjamin J. Bird

    2015-01-01

    Expansion of juniper on U.S. rangelands is a significant environmental concern. Prescribed fire is often recommended to control juniper. To that end, a prescribed burn was conducted in a Great Basin juniper woodland. Conditions were suboptimal; fire did not encroach into mid- or late-seral stages and was patchy in the early-seral stage. This study evaluated the effects...

  8. 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 cons

  9. 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 Pros

  10. 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 nitroge

  11. Floristic composition, structure, and species associations of dry Miombo woodland in Tanzania

    DEFF Research Database (Denmark)

    Mwakalukwa, Ezekiel Edward; Meilby, Henrik; Treue, Thorsten

    2014-01-01

    Village Land Forest Reserve, a dry Miombo woodland area in Tanzania. A total of 35 nested circular plots with radii of 5, 15, and 20 m were used to collect data on woody species and soil samples across the 6,065 ha community-managed forest reserve. Stumps were measured 20 cm above ground. A total of 88...

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. What Drives the Phenology of Carbon Exchange in an Australian Temperate Woodland?

    Science.gov (United States)

    Pendall, E.; Resco de Dios, V.; Cleverly, J. R.; Isaac, P. R.; Renchon, A.; Barton, C. V.; Boer, M. M.; Tissue, D.; Maier, C.

    2015-12-01

    Temperate, broadleaved evergreen woodlands dominated by Eucalyptus species are adapted to a wide range of moisture conditions. However, these ecosystems can be susceptible to extremes of environmental stress, including droughts and heat waves. We evaluated climatic drivers of carbon and water exchange using eddy covariance techniques for over two years in a dry sclerophyll woodland near Sydney, Australia. We found that the strongest net C uptake by this ecosystem occurred during the winter months (June through August), and that precipitation and minimum air temperature were the most important environmental drivers of net uptake. Ecosystem respiration was highest during summer as soil drought was alleviated by frequent thunderstorm events, and lowest during winter due to drier soil and cooler temperatures. Gross primary production was independent of surface soil moisture but was constrained by high VPD during summer. Highest water and light use efficiencies for GPP were observed during winter. This study demonstrates the importance of strong stomatal regulation of dry Eucalyptus woodlands in limiting summer uptake, and warm-season rain in enhancing soil organic matter decomposition, leading to net C losses during summer. The temporal patterns of CO2 fluxes in this mild temperate forest are unusual in comparison to other temperate forests. By persisting through unfavourable conditions and growing in response to favourable conditions during any season, the phenology of C dynamics in temperate sclerophyll woodlands can resemble that of drier ecosystems. The climatic drivers of net C uptake by these woodlands should be considered for evaluating vulnerability to extreme climate events that might limit their productivity as well as ecosystem C storage.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  20. Fuel wood properties of some oak tree species of Manipur, India.

    Science.gov (United States)

    Meetei, Shougrakpam Bijen; Singh, E J; Das, Ashesh Kumar

    2015-07-01

    Five indigenous oak tree species, i.e., Castanopsis indica (Roxb. ex Lindl.) A.DC., Lithocarpus fenestratus (Roxb.) Rehder, Lithocarpus pachyphyllus (Kurz) Rehder, Lithocarpus polystachyus (Wall. ex A.DC.) Rehder and Quercus serrata Murray were estimated for their wood properties such as calorific value, density, moisture content and ash content from a sub-tropical forest of Haraothel hill, Senapati District, Manipur. Wood biomass components were found to have higher calorific value (kJ g(-)) than bark components. The calorific values for tree species were found highest in L. pachyphyllus (17.99 kJ g(-1)) followed by C. indica (17.98 kJ g1), L. fenestratus (17.96 kJ g"), L. polystachyus (17.80 kJ g(-1)) and Q. serrata (17.49 kJ g(-1)). Calorific values for bole bark, bole wood and branch bark were found significantly different (F > 3.48 at p = 0.05) in five oak tree species. Percentage of ash on dry weight basis was found to be highest in Q. serrata (4.73%) and lowest in C. indica (2.19%). Ash content of tree components gives a singnificant factor in determining fuelwood value index (FVI). Of all the five oak tree species, Q. serrata exhibited highest value of wood density (0.78 g cm-) and lowest was observed in C. indica (0.63 g cm(-3)). There was significant correlation between wood density (p L. pachyphyllus (898.41)> L. polystachyus (879.02)> L. fenestratus (824.61)> Q. serrata (792.50). Thus, the present study suggests that C. indica may be considered as a fuelwood oak tree species in Manipur.

  1. The influence of vegetation covers on soil moisture dynamics at high temporal resolution in scattered tree woodlands of Mediterranean climate

    Science.gov (United States)

    Lozano-Parra, Javier; Schnabel, Susanne; Ceballos-Barbancho, Antonio

    2015-04-01

    Soil water is a key factor that controls the organization and functioning of dryland ecosystems. However, in spite of its great importance in ecohydrological processes, most of the studies focus on daily or longer timescales, while its dynamics at shorter timescales are very little known. The main objective of this work was to determine the role of vegetation covers (grassland and tree canopy) in the soil hydrological response using measurements with high temporal resolution in evergreen oak woodland with Mediterranean climate. For this, soil water content was monitored continuously with a temporal resolution of 30 minutes and by means of capacitance sensors, mainly for the hydrological years 2010-2011 and 2011-2012. They were installed at 5, 10 and 15 cm, and 5 cm above the bedrock and depending on soil profile. This distribution along the soil profile is justified because soils are generally very shallow and most of the roots are concentrated in the upper layer. The sensors were gathered in 8 soil moisture stations in two contrasting situations characterized by different vegetation covers: under tree canopy and in open spaces or grasslands. Soil moisture variations were calculated at rainfall event scale at top soil layer and deepest depth by the difference between the final and initial soil moisture registered by a sensor at the finish and the beginning of the rainfall event, respectively. Besides, as soil moisture changes are strongly influenced by antecedent conditions, different antecedent soil moisture conditions or states, from driest to wettest, were also defined. The works were carried out in 3 experimental farms of the Spanish region of Extremadura. Results obtained revealed that rainwater amount bypassing vegetation covers and reaching the soil may temporarily be modified by covers according to precipitation properties and antecedent environmental conditions (from dry to wet) before the rain episode. Rainfall amounts triggering a positive soil

  2. Changes in Structure and Diversity of Woody Plants in a Secondary Mixed Pine-Oak Forest in the Sierra Madre del Sur of Mexico

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Almazán-Núñez

    2016-04-01

    Full Text Available The biotic province of the Sierra Madre del Sur presents a mosaic of woodlands at different successional stages due to frequent modifications in land use. In this study, we analyzed changes in woody flora across three successional stages of pine-oak forest: early, intermediate, and mature. Vegetation composition and diversity were characterized in 10 plots (each 0.28 ha. The mature stage had the highest values for species richness, abundance, and diversity. Pioneer plants were dominant in the early-successional site and may promote the establishment of late-successional species. The vegetation structure was more complex in the mature stage, where members of the Quercus genus were co-dominant with Pinus species. Pine tree richness was highest in the early-successional stage, and its abundance increased at the intermediate-successional site. These results suggest that Pinus species can grow in perturbed and sunny environments but also require favorable edaphic and microclimatic conditions, such as those found in intermediate woodlands. Results of this fieldwork support the initial floristic composition succession model, which suggests that species present at early stages will also occur in subsequent stages. Ecological succession may be considered to be a natural restoration process, and thus, conservation strategies should focus on maintaining distinct successional communities in addition to mature forests in order to preserve a high number of species.

  3. Marketing for Oak Ridge technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Prosser, G.A.

    1989-06-15

    Martin Marietta Energy Systems, Inc., which manages major research and production facilities in Oak Ridge, Tennessee for the Department of Energy, has implemented a systematic approach to marketing for technology transfer. Unique mechanisms have been created to address the need for market research and analysis, strategy formulation, and the execution of plans designed to engender the broadest commercial use of government-funded technologies. Establishment of formal ties with the University of Tennessee Graduate School of Business has resulted in an expanded role for marketing in support of the Oak Ridge program. The creation of graduate research positions has enabled MBA students to contribute to, and learn from, a program which is at the forefront of an important national initiative.

  4. A Review of Polyphenolics in Oak Woods

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2015-03-01

    Full Text Available Polyphenolics, which are ubiquitous in plants, currently are among the most studied phytochemicals because of their perceptible chemical properties and antioxidant activity. Oak barrels and their alternatives, which are widely used in winemaking nowadays, contribute polyphenolics to wines and are thought to play crucial roles in the development of wines during aging. This study summarizes the detailed information of polyphenolics in oak woods and their products by examining their structures and discussing their chemical reactions during wine aging. This paper evaluates the most recent developments in polyphenolic chemistry by summarizing their extraction, separation, and their identification by the use of chromatographic and spectral techniques. In addition, this paper also introduces polyphenol bioactive ingredients in other plant foods.

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

    Directory of Open Access Journals (Sweden)

    Bijendra Lal

    2016-08-01

    Full Text Available 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 m2 ha-1, respectively in forest site-1 and 2 while Quercus leucotrichophora shared maximum (35.69 m2 ha-1 in site-3. The biomass and primary productivity of tree species ranged from 481-569 t ha-1 and 16.9-20.9 t ha-1yr-1, respectively. Of this, biomass and primary productivity of oak tree species accounted for 81 to 95 and 78 to 98%, respectively. Carbon stock and carbon sequestration ranged from 228 to 270 t ha-1 and 8.0 to 9.9 t ha-1yr-1, respectively. The share of oak tree species ranged from 81 to 94.7 and 79 to 97%, respectively. The diversity of tree species ranged from 0.03 to 0.16 in forest sites-1, 2 and 3. The diversity of oak species was 0.08-0.16 in all the forest sites. Thus it is concluded that among the oak tree species, Quercus floribunda and Quercus leucotrichophora were highly dominated in the studied forests. The climax form of oak dominated trees in the studied forest sites depicted slightly lower richness and diversity of tree species compared to the forests in the region and elsewhere. As far as dry matter and carbon of forests is concerned, these estimates are close to the earlier reports of forests in the region. Therefore, studied forests have the potential to increase the diversity, productivity and carbon sequestration of forest tree species by providing the adequate scientific conservation and management inputs.

  6. 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.

  7. Embryogenesis in Oak species. A review

    Directory of Open Access Journals (Sweden)

    Aranzazu Gomez-Garay

    2014-08-01

    Full Text Available Aim of study: A review on the propagation methods of four Quercus species, namely Q. suber, Q. robur, Q. ilex and Q. canariensis, through somatic embryogenesis and anther embryogenesis are presented.Area of study: The study comprises both Mediterranean and Atlantic oak species located in Spain.Material and Methods: Somatic embryogenesis was induced on immature zygotic embryos of diverse oak species, permitting the multiplication of half-sib families. Induction of haploid embryos and doubled haploids was assayed in both Q. suber and Q. ilex by temperature stress treatments of anthers containing late vacuolated microspores. The haploid origin of the anther embryos has been evaluated by quantitative nuclear DNA analysis through flow cytometry and by DNA microsatellite markers. Genetic transformation of cork oak has also been performed by means of Agrobacterium tumefaciens vectors. Proteomic analysis has been conducted to screen the diverse protein profiles followed by in vitro derived embryos during their development.Research highlights: Successful plant regeneration from both somatic and haploid embryos has been achieved. In the particular case of cork oak, doubled-haploid plants were obtained. Plantlets regenerated from selected parent trees through somatic embryogenesis were acclimated in the greenhouse and in the nursery, and were planted in an experimental plot in the field. Preliminary evaluation of the cork quality of the plants showed a good heritability correlation with the parent trees. This article revises the work of and is dedicated to Dr. M.A. Bueno, who devoted much of her professional life to the research on Biotechnology and Genetics of forest species, leading the Laboratory of Forest Biotechnology at the Spanish Institute of Agronomic Research (INIA.Key words: anther embryogenesis; microspore; pollen; Quercus canariensis; Quercus ilex; Quercus robur; Quercus suber; somatic embryogenesis. 

  8. ORNL (Oak Ridge National Laboratory) 89

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.D.; Appleton, B.R.; Jefferson, J.W.; Merriman, J.R.; Mynatt, F.R.; Richmond, C.R.; Rosenthal, M.W.

    1989-01-01

    This is the inaugural issues of an annual publication about the Oak Ridge National Laboratory. Here you will find a brief overview of ORNL, a sampling of our recent research achievements, and a glimpse of the directions we want to take over the next 15 years. A major purpose of ornl 89 is to provide the staff with a sketch of the character and dynamics of the Laboratory.

  9. Delineating demographic units of woodland caribou (Rangifer tarandus caribou in Ontario: cautions and insights

    Directory of Open Access Journals (Sweden)

    Jennifer L. Shuter

    2012-03-01

    Full Text Available Delineating demographic structure across an organism’s range can reveal the extent to which population dynamics in different geographic areas are driven by local or external factors and can be crucial for effective conservation and management. Obtaining optimal data for such analyses can be time and resource-intensive and impending development and resource extraction pressures may necessitate the examination of existing data, even when they are less than ideal. We analyzed a historic telemetry dataset containing satellite radio-collar locations of 73 forest-dwelling woodland caribou in northern Ontario to determine demographic structure. We applied several clustering methods (i.e., agglomerative, divisive and fuzzy k-means to median seasonal locations. Results were used to distinguish demographic units and minimum convex polygons and fixed-kernel density estimates were used to delineate unit boundaries and core areas. For areas where sampling was considered representative of the distribution of caribou on the landscape, we assessed demographic distinctness by evaluating intra-individual variation in cluster membership, membership strength and distance between boundaries and core areas of adjacent units. The number and composition of clusters identified was similar among methods and caribou were grouped into 6 general clusters. The distinctions between the three clusters identified in the central portion of the province (i.e., Lac Seul, Wabakimi, Geraldton and the two clusters identified in the eastern portion of the province (i.e., Cochrane and Cochrane-Quebec were determined to represent demographic structuring. Additional distinctions in other areas (i.e., between The Red Lake and Lac Seul clusters in the west and between the central and eastern clusters may just be artifacts of the original sampling effort. Amongst demographic units, there was no evidence of individual flexibility in cluster membership and average membership strength was

  10. Oak moss extracts in the diagnosis of fragrance contact allergy.

    Science.gov (United States)

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

    2002-03-01

    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 acids which are ingredients of another lichen, tree moss. Resin acids, e.g. abietic acid and dehydroabietic acid, are also the main allergens in colophonium. The aim of the study was to assess whether the contamination of oak moss absolute and thus the FM with resin acids had affected their diagnostic value so that they, instead of indicating fragrance allergy, had become indicators of allergy to resin acids and thus colophonium. Two studies were undertaken. First the relationship between patch test reactions to FM, oak moss absolute, both with contents of resin acids, and colophonium were assessed in 885 consecutive patients. A significant relationship between reactions to colophonium and FM was seen (p < 0.001) as well as a significant relationship between oak moss absolute and colophonium (p < 0.001). The relationship between colophonium and FM was still significant when all reactions to oak moss absolute were disregarded (p < 0.001), showing a relationship also between colophonium and fragrance ingredients other than oak moss absolute. Second, 119 consecutive patients were tested with an old and a new version of oak moss absolute containing resin acid (0.05%) and no measurable resin acid, respectively, and with the corresponding FM. No overall difference in reactivity to the old and new version of oak moss absolute/FM was seen. It is concluded the diagnostic value of oak moss absolute as indicator fragrance contact allergy has been and is unaffected by the resin acid contamination.

  11. A Tree-based Approach for Modelling Interception Loss From Evergreen Oak Mediterranean Savannas

    Science.gov (United States)

    Pereira, Fernando L.; Gash, John H. C.; David, Jorge S.; David, Teresa S.; Monteiro, Paulo R.; Valente, Fernanda

    2010-05-01

    Evaporation of rainfall intercepted by tree canopies is usually an important part of the overall water balance of forested catchments and there have been many studies dedicated to measuring and modelling rainfall interception loss. These studies have mainly been conducted in dense forests; there have been few studies on the very sparse forests which are common in dry and semi-arid areas. Water resources are scarce in these areas making sparse forests particularly important. Methods for modelling interception loss are thus required to support sustainable water management in those areas. In very sparse forests, trees occur as widely spaced individuals rather than as a continuous forest canopy. We therefore suggest that interception loss for this vegetation type can be more adequately modelled if the overall forest evaporation is derived by scaling up the evaporation from individual trees. The evaporation rate for a single tree can be estimated using a simple Dalton-type diffusion equation for water vapour as long as its surface temperature is known. From theory, this temperature is shown to be dependent upon the available energy and windspeed. However, the surface temperature of a fully saturated tree crown, under rainy conditions, should approach the wet bulb temperature as the radiative energy input to the tree reduces to zero. This was experimentally confirmed from measurements of the radiation balance and surface temperature of an isolated tree crown. Thus, evaporation of intercepted rainfall can be estimated using an equation which only requires knowledge of the air dry and wet bulb temperatures and of the bulk tree-crown aerodynamic conductance. This was taken as the basis of a new approach for modelling interception loss from savanna-type woodland, i.e. by combining the Dalton-type equation with the Gash's analytical model to estimate interception loss from isolated trees. This modelling approach was tested using data from two Mediterranean savanna-type oak

  12. Dalechampii oak (Quercus dalechampii Ten., an important host plant for folivorous lepidoptera larvae

    Directory of Open Access Journals (Sweden)

    Kulfan, M.

    2013-06-01

    Full Text Available We conducted a structured analysis of lepidoptera larvae taxocenoses living in leaf bearing crowns of Dalechampii oak (Quercus dalechampii Ten. in nine study plots in the Malé Karpaty Mountains (Central Europe. The differences between lepidoptera taxocenoses in individual oak stands were analyzed. A total of 96 species and 2,140 individuals were found. Species abundance peaked in May, while number of species and species diversity reached the highest values from April to May and from April to June, respectively. Abundance showed two notable peaks in flush feeders and in late summer feeders. Lepidoptera taxocenosis in the study plot Horný háj (isolated forest, high density of ants differed significantly from all other taxocenoses according to Sörensen’s index of species similarity, species diversity, analysis of similarity on the basis of permutation and pairwise tests (ANOSIM, seasonal variability of species composition, and NMDS ordination.

  13. Radiant flux density, energy density, and fuel consumption in mixed-oak forest surface fires

    Science.gov (United States)

    R.L. Kremens; M.B. Dickinson; A.S. Bova

    2012-01-01

    Closing the wildland fire heat budget involves characterising the heat source and energy dissipation across the range of variability in fuels and fire behaviour. Meeting this challenge will lay the foundation for predicting direct ecological effects of fires and fire-atmosphere coupling. In this paper, we focus on the relationships between the fire radiation field, as...

  14. Assessment of nest fates of woodland songbirds in J. Clark Slayer National Wildlife Refuge : 2002 progress report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Progress report for the 2002 field season of a study to assess nest fates of woodland songbirds in J. Clark Slayer National Wildlife Refuge (JCSNWR), in northcentral...

  15. 林地地租量化研究%A Study on the Calculation of Woodland Rent

    Institute of Scientific and Technical Information of China (English)

    邹秀清; 张志云

    2001-01-01

    以马克思地租理论为指导,阐明市场经济条件下我国林地地租的内涵及特征:求出零级土地的立地指数等级和各立地等级的年级差地租,从总地租中分离出绝对地租和级差地租。%Guided by Marxist land rent theory, under the condition of market economy, the connotation and characteristics of woodland rent in our country are expounded. By calculating site index of zero-leveled woodland, annually differential woodland rent has been separated from absolute woodland rent among total rent.

  16. The impact of broadleaved woodland on water resources in lowland UK: II. Evaporation estimates from sensible heat flux measurements over beech woodland and grass on chalk sites in Hampshire

    Directory of Open Access Journals (Sweden)

    J. Roberts

    2005-01-01

    Full Text Available The impact on recharge to the Chalk aquifer of substitution of broadleaved woodland for pasture is a matter of concern in the UK. Hence, measurements of energy balance components were made above beech woodland and above pasture, both growing on shallow soils over chalk in Hampshire. Latent heat flux (evaporation was calculated as the residual from these measurements of energy balances in which sensible heat flux was measured with an eddy correlation instrument that determined fast response vertical wind speeds and associated temperature changes. Assessment of wind turbulence statistics confirmed that the eddy correlation device performed satisfactorily in both wet and dry conditions. There was excellent agreement between forest transpiration measurements made by eddy correlation and stand level tree transpiration measured with sap flow devices. Over the period of the measurements, from March 1999 to late summer 2000, changes in soil water content were small and grassland evaporation and transpiration estimated from energy balance-eddy flux measurements were in excellent agreement with Penman estimates of potential evaporation. Over the 18-month measurement period, the cumulative difference between broadleaved woodland and grassland was small but evaporation from the grassland was 3% higher than that from the woodland. In the springs of 1999 and 2000, evaporation from the grassland was greater than that from the woodland. However, following leaf emergence in the woodland, the difference in cumulative evaporation diminished until the following spring.

  17. Vegetation characteristics of forest stands used by woodland caribou and those disturbed by fire or logging in Manitoba

    Directory of Open Access Journals (Sweden)

    Juha M. Metsaranta

    2003-04-01

    Full Text Available This study examined woodland caribou (Rangifer tarandus caribou in an area known as the Kississing-Naosap caribou range in west central Manitoba. The vegetation characteristics of areas used by caribou and areas disturbed by fire or logging were measured in order to develop a model to estimate habitat quality from parameters collected during stan¬dard resource inventories. There was evidence that habitat index values calculated using a visual score-sheet index could be used as the basis to relate parameters commonly collected during resource inventories to habitat suitability. Use of this model to select long and short-term leave areas during forest management planning could potentially mitigate some of the negative impacts of forest harvesting. Abundance of arboreal lichen and wind-fallen trees were important predictor variables in the suitability model, but their inclusion did not explain more variance in habitat suitability than models that did not include them. Extreme post-fire deadfall abundance may play a role in predator-prey dynamics by creating habitat that is equally unsuitable for all ungulates, and thus keeping both moose and caribou densities low.

  18. 76 FR 78908 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation

    Science.gov (United States)

    2011-12-20

    ..., Department of Energy Oak Ridge Operations Office, P.O. Box 2001, EM-90, Oak Ridge, TN 37831. Phone (865) 241... and Reuse. The speaker will be Brian Henry, DOE Oak Ridge. Public Participation: The EM SSAB,...

  19. Relation between Growth and Vertical Distribution of Fine Roots and Soil Density in the Weibei Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhong; Li Peng; Xue Wenpeng; Guo Shengwu

    2006-01-01

    The influence of woodland soil bulk density on the growth and distribution of fine root system of main planting tree species in the Weibei Loess Plateau was investigated by means of pot culture and field survey.Results indicated that in the woodland of Pinus tabulaeformis,soil bulk density increased with the depth at different sites,while in the woodland of Robinia pseudoacacia,soil bulk density was higher than that in P.tabulaeformis,and there was no clear difference across the profile.Further analysis implied that there existed negative correlations between soil bulk density and fine root length in the woodland of P.tabulaeformis.Results from pot culture indicated that although the effects of pot culture media on the free root growth and development of different tree species seedlings were different,all treated seedlings grew better in the soil matter with medium bulk density and porosity and with the biggest biomass.Bulk density of pot culture media had clear effects on the growth and development of P.tabulaeformis and R.pseudoacacia seedling roots,especially on the former,whereas it had little effect on that of Platycladus orientalis and Prunus armeniaca var.ansu,whose fine root biomass changed little in different pot culture media.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  1. Quality of rooting environments and patterns of root colonization by arbuscular mycorrhizal fungi in strangler figs in a Mexican palmetto woodland.

    Science.gov (United States)

    Guevara, Roger; López, Juan C

    2007-10-01

    Arbuscular mycorrhizal colonization in strangler figs, spore richness, and abundance of arbuscular mycorrhizal fungi were quantified in epiphytic and ground-rooted trees in a Sabal palmetto woodland that had marked heterogeneity in rooting environments for hemiepiphytic plants. An inoculation experiment was performed to assess whether low spore density could limit mycorrhizal colonization. There was no significant difference in mycorrhizal colonization among Ficus species, but epiphytic plants in nutrient-rich rooting environments had less mycorrhizal colonization than ground-rooted plants in low-nutrient soils. However, richness and abundance of spores was low, and to some extent, this limited the mycorrhizal colonization of strangler figs. Nevertheless, our results suggest intraindividual adjusting levels of root colonization in strangler figs in accordance with mineral availability. Such responses could maximize the cost-benefit balance of arbuscular mycorrhizal interactions throughout the development of strangler figs from epiphytic young plants to ground-rooted trees.

  2. Prey specialization and morphological conformation of wolves associated with woodland caribou and moose

    Directory of Open Access Journals (Sweden)

    David M.A. Wiwchar

    2012-03-01

    Full Text Available Morphological analysis of wolves associated with woodland caribou in late succession boreal coniferous forests north of the commercial cut line and those associated with moose in early succession boreal deciduous forests south of the commercial cut line were studied in Ontario. Socalled “moose-wolves” could readily be distinguished from “caribouwolves” in both genders using a few morphological measurements. Wolves associated with woodland caribou were significantly smaller in most measurements, and increased in size within seven years post-harvest as moose totally replaced caribou in the ecosystem. Whether this change in wolf morphology is related to micro-evolutionary change, the migration of larger “moose-wolves” into the area, or both, remains unclear.

  3. Allometry and growth of eight tree taxa in United Kingdom woodlands.

    Science.gov (United States)

    Evans, Matthew R; Moustakas, Aristides; Carey, Gregory; Malhi, Yadvinder; Butt, Nathalie; Benham, Sue; Pallett, Denise; Schäfer, Stefanie

    2015-01-01

    As part of a project to develop predictive ecosystem models of United Kingdom woodlands we have collated data from two United Kingdom woodlands - Wytham Woods and Alice Holt. Here we present data from 582 individual trees of eight taxa in the form of summary variables relating to the allometric relationships between trunk diameter, height, crown height, crown radius and trunk radial growth rate to the tree's light environment and diameter at breast height. In addition the raw data files containing the variables from which the summary data were obtained. Large sample sizes with longitudinal data spanning 22 years make these datasets useful for future studies concerned with the way trees change in size and shape over their life-span.

  4. 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.

  5. Preliminary analysis of habitat utilization by woodland caribou in northwestern Ontario using satellite telemetry

    Directory of Open Access Journals (Sweden)

    T.L. Hillis

    1998-03-01

    Full Text Available Locational data collected over a one year period from 10 female woodland caribou, Rangifer tarandus caribou, collared with Argos satellite collars in northwestern Ontario, Canada were superimposed on supervised Landsat images using Geographical Information System (GIS technology. Landscape parameters, land cover classifications, and drainage were utilized to create the basemap. Using ARCVIEW software, all digital fixes from collared caribou with information of date, time, and activity status were overlain on the basemap to facilitate a preliminary analysis of habitat use in this species. Results supported the conclusions (1 that woodland caribou in northwestern Ontario select habitats containing high to moderate conifer cover and avoided disturbed areas and shrub-rich habitats, (2 that seasonal changes in habitat utilization occurs in females of this species, and (3 that satellite telemetry technology can be employed in the boreal forest ecosystem to assess habitat utilization by large ungulate species.

  6. Integration of woodland caribou habitat management and forest management in northern Ontario - current status and issues

    Directory of Open Access Journals (Sweden)

    Ted (E.R Armstrong

    1998-03-01

    Full Text Available Woodland caribou {Rangifer tarandus caribou range across northern Ontario, occurring in both the Hudson Bay Lowlands and the Boreal Forest. Woodland caribou extend south well into the merchantable forest, occurring in licensed and/or actively managed Forest Management Units (FMU's across the province. Caribou range has gradually but continuously receded northward over the past century. Since the early 1990's, the Ontario Ministry of Natural Resources (OMNR has been developing and implementing a woodland caribou habitat management strategy in northwestern Ontario. The purpose of the caribou habitat strategy is to maintain woodland caribou occupancy of currently occupied range in northwestern Ontario. Long-term caribou habitat needs and predator-prey dynamics form the basis of this strategy, which requires the development of a landscape-level caribou habitat mosaic across the region within caribou range. This represents a significant change from traditional forest management approaches, which were based partially upon moose (Alces alces habitat management principles. A number of issues and concerns regarding implications of caribou management to the forest industry are being addressed, including short-term and long-term reductions in wood supply and wood quality, and increased access costs. Other related concerns include the ability to regenerate forests to pre-harvest stand conditions, remote tourism concerns, implications for moose populations, and required information on caribou biology and habitat. The forest industry and other stakeholders have been actively involved with the OMNR in attempting to address these concerns, so that caribou habitat requirements are met while ensuring the maintenance of a viable timber industry, other forest uses and the forest ecosystem.

  7. Wetland habitat selection by woodland caribou as characterized using the Alberta Wetland Inventory

    OpenAIRE

    W. Kent Brown; W. James Rettie; Bob Wynes; Kim Morton

    2011-01-01

    We examined habitat selection by woodland caribou (Rangifer tarandus caribou) in northwestern Alberta based on a wetland classification system developed for the Alberta Vegetation Inventory. Our two objectives were to describe caribou habitat use, and to assess the utility of the wetland classification system in land-use planning on caribou range. We used a geographical information system to overlay the locations of radio-collared caribou on the habitat map. Using a "moving-window" analysis o...

  8. Relative importance of perch and facilitative effects on nucleation in tropical woodland in Malawi

    Science.gov (United States)

    Fujita, Tomohiro

    2016-01-01

    Individual trees in open vegetation such as woodlands can act as "nuclei" for the colonization of forest tree species, which consequently lead to the formation of forest patches. This phenomenon is known as nucleation. The mechanism of nucleation is generally attributed to two factors: trees provide perches for frugivores that increase seed deposition (perch effect), and tree crowns ameliorate environmental conditions, which improves seedling establishment (facilitative effect). Few studies have attempted to distinguish the relative importance of these two factors. In this study, I separated these two effects in a woodland in northern Malawi. I chose Ficus natalensis as a potential nuclei tree because large individuals of this species are commonly located at the center of forest patches within open woodland at the study site. I monitored several environmental variables, seedling survival, seedling composition, and seed rain at three microsites: under F. natalensis, under Brachystegia floribunda (a dominant woodland species), and in open sites. Both tree species provided similar favorable conditions for the establishment of forest species compared to open sites. Thus, the survival of forest tree seedlings under F. natalensis and B. floribunda was similar, and substantially higher than seedling survival in open sites. However, communities of naturally occurring seedlings differed significantly between F. natalensis and B. floribunda. These results indicate that the facilitative effect alone cannot explain the nucleation pattern. I attribute this result to the perch effect of F. natalensis because the forest seedling species recorded under F. natalensis reportedly have small, brightly colored diaspores, which are indicative of dispersal by birds. Seed deposition of forest species under F. natalensis was significantly higher than that under B. floribunda or in open sites. My findings reinforce the idea that trees will lead to nucleation when they enhance seed

  9. Woodland: Dynamics of Deciduous Tree Stand Average Diameters of the Principal Forest Types

    Directory of Open Access Journals (Sweden)

    R. A. Ziganshin

    2014-06-01

    Full Text Available The analysis of age dynamics of average diameters of a deciduous tree stands of different forest types at Highland Khamar-Daban (natural woodland in South-East Baikal Lake region has been done. The aggregate data of average tree stand diameters by age classes, as well as tree stand current periodic and overall average increment are presented and discussed in the paper. Forest management appraisal is done.

  10. Evaluation of Propiconazole Application Methods for Control of Oak Wilt in Texas Live Oaks

    Science.gov (United States)

    A. Dan Wilson; D.G. Lester

    1996-01-01

    Four fungicide application methods using the microencapsulated (blue) 14.3% EC formulation of propiconazole (Alamo), including a low-concentration high volume method, two high-concentration low volume microinjection methods, and a low-concentration intermediate volume soil drench method, were tested for effectiveness in controlling oak wilt in a mature natural stand of...

  11. 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.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. The carbon accumulation and dissipation features of sub—alpine woodland in Mt.Gongga

    Institute of Scientific and Technical Information of China (English)

    CHENGGenwei

    2003-01-01

    Based on biomass investigations,soil respiration and plant photosynthesis measurement of dominant trees in Hailuogou valley of Mt.Gongga,Southwest China,the carbon(C) storage,absorption and release for several typical woodlands in sub-alpine zones have been discussed.For Abies fahri forest of 3,000 m above sea level,the Cstorage amount is 177.4t/ha for above-ground biomass and 143.2 t/ha for soil below-ground biomass. The annual gross C fixed by vegetation photosynthesis is 20-24 t/ha. The C release by canopy respiration is 3.0-5.5 t/ha for arbors and 10-19 t/ha for surface soil and roots.The annual net C fixed of forest ecosystem is about 6.0-7.1 t/ha.At lower elevations,the amount of C released by woodlands is higher than that of woods at higher elevations.The C fixed capacity of renewed forest with middle-aged trees is higher than that of mature forest.Before becoming over-matured forest,woodland is an important sink of C whereas bareland in woods is the source of atmospheric C.

  15. The Woodlands Metro Center energy study. Case studies of project planning and design for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    The Woodlands is a HUD Title VII New Town located near Houston, including 22,000 acres; the plan for the new town consists of 6 residential villages, a town center (Metro), and a Trade Center for larger-scale industrial use. Included within the program for each village are schools and commercial activities, as well as employment activities. The Woodlands is planned to be developed over a 26-year period (commenced in 1972) with an ultimate population of 150,000. Following a summary chapter, Chapter II presents background material on The Woodlands and results of the study are summarized. Chapter III describes the project team and its organizational structure. Chapter IV outlines and documents the methodology that was employed in developing, analyzing, and evaluating the case study. The next chapter describes and analyzes the conventional plan, documents the process by which energy-conserving methods were selected, and evaluates the application of these methods to the Metro Center Study area. Chapter VI discusses constraints to implementation and is followed by a final chapter that presents the general conclusions from the case study and suggests directions for further investigation.

  16. Field Use of NMIS at Oak Ridge

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, L.G.; Conger, M.; Hughes, S.S.; Mattingly, J.K.; McEvers, J.A.; Mihalczo, J.T.; Mullens, J.A.; Perez, R.B.; Turner, C.R.; Uckan, T.; Valentine, T.E.

    1999-08-26

    The Nuclear Materials Identification System (NMIS), developed by the Oak Ridge National Laboratory and Oak Ridge Y-12 Plant (Y-12), has been successfully used at Y-12 for nuclear material control and accountability (NMC&A). It is particularly useful in the high gamma-ray background of storage arrays and for shielded HEU. With three systems in use at Y-12, NMIS has enhanced the NMC&A capability for verification and for confirmation of materials in storage and for HEU receipts by providing capability not available or practical by other NDA methods for safeguards. It has recently cost-effectively quantified the HEU mass and enrichment of hundreds of HEU metal items to within a total spread of {+-} 5% (3 sigma) with and mean deviations for all HEU verified of + 0.2% for mass and {minus}0.2% for enrichment. Three cart portable systems are easily moved around with minimal impact on facility operations since no permanent dedicated floor space is required. The positive impact of NMIS at the Oak Ridge Y-12 Plant is improved and more cost effective NMC&A as well as the resolution of NMC&A findings. Its operation at the Y-12 Plant is essential for compliance with the NMC&A requirements of the US Department of Energy. NMIS portability has allowed one system to be moved temporarily to the former K-25 Gaseous Diffusion Plant for characterization of a large deposit of hydrated uranyl fluoride. The impact of this NMIS application was enhanced and verified nuclear criticality safety that led to the safe removal of a large deposit originally estimated by gamma-ray spectrometry and neutron counting to contain 1300 kg of 3.3 wt% {sup 235}U material. NMIS has also been operational at Los Alamos National Laboratory and Pantex.

  17. Oak Ridge Leadership Computing Facility Position Paper

    Energy Technology Data Exchange (ETDEWEB)

    Oral, H Sarp [ORNL; Hill, Jason J [ORNL; Thach, Kevin G [ORNL; Podhorszki, Norbert [ORNL; Klasky, Scott A [ORNL; Rogers, James H [ORNL; Shipman, Galen M [ORNL

    2011-01-01

    This paper discusses the business, administration, reliability, and usability aspects of storage systems at the Oak Ridge Leadership Computing Facility (OLCF). The OLCF has developed key competencies in architecting and administration of large-scale Lustre deployments as well as HPSS archival systems. Additionally as these systems are architected, deployed, and expanded over time reliability and availability factors are a primary driver. This paper focuses on the implementation of the Spider parallel Lustre file system as well as the implementation of the HPSS archive at the OLCF.

  18. Toxicodendron dermatitis: poison ivy, oak, and sumac.

    Science.gov (United States)

    Gladman, Aaron C

    2006-01-01

    Allergic contact dermatitis caused by the Toxicodendron (formerly Rhus) species-poison ivy, poison oak, and poison sumac-affects millions of North Americans every year. In certain outdoor occupations, for example, agriculture and forestry, as well as among many outdoor enthusiasts, Toxicodendron dermatitis presents a significant hazard. This review considers the epidemiology, identification, immunochemistry, pathophysiology, clinical features, treatment, and prevention of this common dermatologic problem. Recent research in prevention is emphasized, and resources to help in the identification of plants are provided in the bibliography. The literature was searched using a MEDLINE query for "Toxicodendron dermatitis", and the identified article bibliographies were searched as well.

  19. Oak Ridge Reservation Annual Site environmental report summary for 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This document presents a summary of the information collected for the Oak Ridge Reservation 1994 site environmental report. Topics discussed include: Oak Ridge Reservation mission; ecology; environmental laws; community participation; environmental restoration; waste management; radiation effects; chemical effects; risk to public; environmental monitoring; and radionuclide migration.

  20. 60 Years of Great Science (Oak Ridge National Laboratory)

    Science.gov (United States)

    2003-01-01

    This issue of Oak Ridge National Laboratory Review (vol. 36, issue 1) highlights Oak Ridge National Laboratory's contributions in more than 30 areas of research and related activities during the past 60 years and provides glimpses of current activities that are carrying on this heritage.

  1. Pollination biology of northern red and black oak

    Science.gov (United States)

    Robert A. Cecich; William W. Haenchen

    1995-01-01

    Pistillate flower abortion in northern red oak and black oak was evaluated in relation to pollination and fertilization. The presence, position, and characteristics of the pollen grains, pollen tubes, and ovules were determined with bright field and fluorescence microscopy. Flower survival counts were made weekly, from late April to mid- September. Both species have...

  2. Blue Oak Canopy Effect on Seasonal Forage Production and Quality

    Science.gov (United States)

    William E. Frost; Neil K. McDougald; Montague W. Demment

    1991-01-01

    Forage production and forage quality were measured seasonally beneath the canopy of blue oak (Quercus douglasii) and in open grassland at the San Joaquin Experimental Range. At the March and peak standing crop sampling dates forage production was significantly greater (p=.05) beneath blue oak compared to open grassland. At most sampling dates, the...

  3. Eaten out of house and home: impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands.

    Science.gov (United States)

    Howland, Brett; Stojanovic, Dejan; Gordon, Iain J; Manning, Adrian D; Fletcher, Don; Lindenmayer, David B

    2014-01-01

    Large mammalian grazers can alter the biotic and abiotic features of their environment through their impacts on vegetation. Grazing at moderate intensity has been recommended for biodiversity conservation. Few studies, however, have empirically tested the benefits of moderate grazing intensity in systems dominated by native grazers. Here we investigated the relationship between (1) density of native eastern grey kangaroos, Macropus giganteus, and grass structure, and (2) grass structure and reptiles (i.e. abundance, richness, diversity and occurrence) across 18 grassland and grassy Eucalyptus woodland properties in south-eastern Australia. There was a strong negative relationship between kangaroo density and grass structure after controlling for tree canopy cover. We therefore used grass structure as a surrogate for grazing intensity. Changes in grazing intensity (i.e. grass structure) significantly affected reptile abundance, reptile species richness, reptile species diversity, and the occurrence of several ground-dwelling reptiles. Reptile abundance, species richness and diversity were highest where grazing intensity was low. Importantly, no species of reptile was more likely to occur at high grazing intensities. Legless lizards (Delma impar, D. inornata) were more likely to be detected in areas subject to moderate grazing intensity, whereas one species (Hemiergis talbingoensis) was less likely to be detected in areas subject to intense grazing and three species (Menetia greyii, Morethia boulengeri, and Lampropholis delicata) did not appear to be affected by grazing intensity. Our data indicate that to maximize reptile abundance, species richness, species diversity, and occurrence of several individual species of reptile, managers will need to subject different areas of the landscape to moderate and low grazing intensities and limit the occurrence and extent of high grazing.

  4. Eaten out of house and home: impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands.

    Directory of Open Access Journals (Sweden)

    Brett Howland

    Full Text Available Large mammalian grazers can alter the biotic and abiotic features of their environment through their impacts on vegetation. Grazing at moderate intensity has been recommended for biodiversity conservation. Few studies, however, have empirically tested the benefits of moderate grazing intensity in systems dominated by native grazers. Here we investigated the relationship between (1 density of native eastern grey kangaroos, Macropus giganteus, and grass structure, and (2 grass structure and reptiles (i.e. abundance, richness, diversity and occurrence across 18 grassland and grassy Eucalyptus woodland properties in south-eastern Australia. There was a strong negative relationship between kangaroo density and grass structure after controlling for tree canopy cover. We therefore used grass structure as a surrogate for grazing intensity. Changes in grazing intensity (i.e. grass structure significantly affected reptile abundance, reptile species richness, reptile species diversity, and the occurrence of several ground-dwelling reptiles. Reptile abundance, species richness and diversity were highest where grazing intensity was low. Importantly, no species of reptile was more likely to occur at high grazing intensities. Legless lizards (Delma impar, D. inornata were more likely to be detected in areas subject to moderate grazing intensity, whereas one species (Hemiergis talbingoensis was less likely to be detected in areas subject to intense grazing and three species (Menetia greyii, Morethia boulengeri, and Lampropholis delicata did not appear to be affected by grazing intensity. Our data indicate that to maximize reptile abundance, species richness, species diversity, and occurrence of several individual species of reptile, managers will need to subject different areas of the landscape to moderate and low grazing intensities and limit the occurrence and extent of high grazing.

  5. The Influence of Woodland Encroachment on Runoff and Erosion in Sagebrush Steppe Systems, Great Basin, USA.

    Science.gov (United States)

    Pierson, F. B.; Kormos, P. R.; Williams, C. J.

    2007-12-01

    Pinyon and juniper woodlands have expanded 10 to 30% in the past 30 years and now occupy nearly 20 million hectares of sagebrush shrub steppe in the Great Basin Region and Colorado Plateau, USA. The conversion of sagebrush steppe to pinyon and juniper woodlands has been linked to changes in plant community structure and composition and respective increases in overland flow and erosion from these landscapes. The Sagebrush Steppe Treatment Evaluation Project (SageSTEP, www.sagestep.org) was implemented in 2005 as a 5 year interdisciplinary research study to evaluate restoration methodologies for sagebrush rangelands degraded by woodland and grassland encroachment over a six state area within the Great Basin. The hydrology component of SageSTEP focuses on the relationships between changes in vegetation and groundcover and runoff/erosion processes. In 2006, 140 small scale (0.5 m2) rainfall simulations were conducted at 2 locations within the Great Basin to determine whether critical thresholds exist in vegetation and ground cover that significantly influence infiltration, runoff, and erosion in pinyon and juniper woodlands. Simulation plots were distributed on interspaces (areas between shrub/tree canopies) and juniper, pinyon, and shrub coppices (areas underneath canopy). Water drop penetration times and litter depths were also collected for each plot to explore controls on soil hydrophobicity. Preliminary results suggest a positive correlation between litter depth and hydrophobicity, as soils under thick pinyon and juniper coppices are strongly water repellant and soils in interspaces and under shrub coppices are easily wettable. Interspace plots with varying amounts of grasses and forbs have the highest erosion and runoff rates due to higher percentages of bare ground and relatively low soil stability. Pinyon coppices have the least runoff and erosion due to very high litter depths and low bare ground cover, even though surface soils are hydrophobic. Juniper and

  6. Wettability, polarity, and water absorption of holm oak leaves: effect of leaf side and age.

    Science.gov (United States)

    Fernández, Victoria; Sancho-Knapik, Domingo; Guzmán, Paula; Peguero-Pina, José Javier; Gil, Luis; Karabourniotis, George; Khayet, Mohamed; Fasseas, Costas; Heredia-Guerrero, José Alejandro; Heredia, Antonio; Gil-Pelegrín, Eustaquio

    2014-09-01

    Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition, and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of holm oak (Quercus ilex) as a model. By measuring the leaf water potential 24 h after the deposition of water drops onto abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water-repellent abaxial holm oak leaf sides. The surface free energy and solubility parameter decreased with leaf age, with higher values determined for the adaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition, and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical chemistry, and plant ecophysiology.

  7. Scale-dependent segregation of seeders and resprouters in cork oak (Quercus suber) forests.

    Science.gov (United States)

    Coca, M; Pausas, J G

    2012-02-01

    Recent studies showed that disturbances and water availability determine the richness among plants with different post-fire strategies of Mediterranean-type ecosystems. The aim of this study was to determine whether or not the scale of analysis has an influence on the effects of these factors and, therefore, on the segregation of the dominant post-fire strategies, obligate seeders and obligate resprouters, and facultative species. We recorded all woody species and geographical features on 94 (75 m(2)) plots of cork oak woodlands in the southern Iberian Peninsula. For each regenerative type (resprouters, seeders and species with both traits--facultative species), we tested the relationship between the number of species and the predictors using a generalised linear mixed model. The fixed predictor considered at the large scale was altitude, and fixed predictors considered at the local scale were aspect (north/south) and disturbance (fire and clearing by heavy machinery; yes/no). The random predictor was the factor of site. When this factor did not have significant effect for some regenerative types, these relationships was tested using a generalised linear model. Resprouting species were most represented at lower altitudes and in undisturbed sites, while seeders were also at lower altitudes but mostly on south-facing slopes, especially south-facing disturbed sites. For facultative species, site is the most important variable. The proportion of seeders from the total species is not related to altitude, but it is related to disturbance and aspect. These results suggest that there is no segregation of the richness of seeders and resprouters at the large scale (altitudinal gradient). Differences appeared at the local scale (aspect and disturbance).

  8. 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

  9. 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 ...

  10. Performance of nutrient-loaded red oak and white oak seedlings on mine lands in southern Indiana

    Science.gov (United States)

    K. Francis Salifu; Douglass F. Jacobs; Zonda K. D. Birge

    2008-01-01

    Exponential nutrient loading was used to build nutrient reserves in northern red oak (Quercus rubra) and white oak (Q. alba) seedlings during standard bareroot nursery culture at the Vallonia State Nursery, Indiana. Nursery grown seedlings were outplanted the following year onto a mine reclamation site in southern Indiana to...

  11. Seasonal Variability in Soil Inorganic Nitrogen Across Borders Between Woodland and Farmland in the Songnen Plain of Northeast China

    Institute of Scientific and Technical Information of China (English)

    LIN Chang-Cun; FU Yao; LIU Li; WANG Kun; WANG De-Li

    2013-01-01

    To study the seasonal variability of soil inorganic nitrogen (N) across borders at the woodland-farmland ecotone and potential mechanisms,contents of soil inorganic N were measured during the dry season (May 20 and June 30) and the rainy season (August 10 and September 20) of 2006 in the Songnen Plain of Northeast China.The borders between farmland and woodland were determined by a border-and-ecotone detection analysis (BEDA).The ecotone limits,often referred to as the depth-of-edge influence (DEI),are critical for determining the scale at which edge effect operates.The results showed that the soil inorganic N border between the woodland and farmland was located further toward the woodland interior during the rainy season (DEI =53.4 ±-8.7 m,August 10) than during the dry season (DEI =35.0 ± 12.6 m,May 20).The seasonal variability in the soil inorganic N border was found to be associated with seasonal changes of deposition flux of N (the correlation coefficients between them for the dry season and rainy season were 0.61 and 0.67,respectively),which resulted from foliation patterns of trees and crops.Accordingly,the leaf area index at woodland edges was lower than that in the woodland interior,so woodland edges captured large amounts of atmosphere nitrogen deposition.The average DEI was 44.1 m,which was in accordance with the values of other temperate forest boundaries in literatures; therefore,BEDA was an appropriate method to estimate the borders of ecotones.

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

    Science.gov (United States)

    Knick, Steven T.; Hanser, Steve; 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.

  13. Assessment and Management of Oak Coppice Stands (Quercus variabilis) in Shangnan County,Southern Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    Xiao-lan Wang; Hany El Kateb; Bernhard Felbermeier; Ping-cang Zhang; Reinhard Mosandl

    2012-01-01

    The present study was conducted within the frame of the Sino-German project " Rehabilitation of degraded land ecosystems in the mountainous area of the Southern Shaanxi Province,China".The study deals with the assessment of the potential of oak coppices as well as the evaluation of the socioeconomic conditions in the Shangnan County.The ulimate objective of the study is to provide recommendations on the sustainable management of forest resources,which does not only aim to improve the environmental situation but also to satisfy the demands of the local rural residents.The study was based on 30 samples of oak coppices stands,which were randomly selected within an area of a size of 20 km × 20 km.In each selected stand,the mature stand and understory regeneration were investigated in depth.For the socio-economic survey,175 households from 11 villages were randomly selected.Results revealed that the stocking capacity of the cork oak coppices reaches 120 m3/ha in average at the older age classes (≥25 years) even after frequent timber harvest.High potential for productivity was indicated by the availability of sufficient vigorous individuals at different age classes.In addition,the understory regeneration was sufficient in density (19,000 ± 133 individual/ha) and consisted of diverse valuable nativespecies (17 species within a survey area of 400 m2).The results of the assessment of the oak coppices provided possibilities for some practices that can be recommended towards sustainable management of such stands.On the other hand,results of the socioeconomic study showed a high degree of acceptance among the local inhabitants (79% of the total households)to change traditional land use,providing an enhancement of their economic situation.

  14. Differences in photosynthesis and isoprene emission in post oak (Quercus stellata) and sweetgum (Liquidambar styraciflua) trees along an urban-to-rural gradient in Texas

    Science.gov (United States)

    Crossett, C.; Lahr, E.; Haas, G.; Schade, G. W.

    2014-12-01

    Many plants produce isoprene, a volatile organic compound that can mitigate damage to photosynthetic systems during short- or long-term increases in leaf temperature. After its production within leaves, isoprene is emitted to the atmosphere and influences regional atmospheric chemistry. Here, we use an urban-to-rural gradient to explore future effects of climate change on tree eco-physiology and feedbacks to atmospheric chemistry. Urban areas mimic many of the conditions expected to occur in the future; in particular, cities have warmer temperatures due to the urban heat island (UHI) effect, and less water availability relative to rural areas. Along a 90 km urban-to-rural gradient, we measured photosynthesis and isoprene emission from trees at three sites in eastern Texas: Houston (urban), The Woodlands (suburban) and Sam Houston National Forest (rural). Isoprene emission from post oak (Quercus stellata) was higher in Houston than the other sites, and when leaf temperatures were increased above ambient conditions, trees produced more isoprene. Leaves produced more isoprene at high leaf temperatures in early summer than in late summer, suggesting gradual acclimation of photosynthetic processes over the course of the summer. We also found that sweetgum (Liquidambar styraciflua) emitted more isoprene than post oak, but when leaf temperatures were increased, isoprene emission was exhausted more quickly in sweetgum relative to post oak. At the same time, post oak maintained higher levels of photosynthesis seasonally and during short-term temperature increases. Both post oak and sweetgum are significant isoprene emitters and represent approximately two and four percent crown cover in the United States, respectively. Our results suggest that in a warming climate, we can expect trees to produce more isoprene seasonally and in response to short-term temperature extremes, and that species-specific differences in photosynthesis and isoprene emission may play an important role

  15. Source document for waste area groupings at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, P.L.; Kuhaida, A.J., Jr.

    1996-09-01

    This document serves as a source document for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and other types of documents developed for and pertaining to Environmental Restoration (ER) Program activities at Oak Ridge National Laboratory (ORNL). It contains descriptions of the (1) regulatory requirements for the ORR ER Program, (2) Oak Ridge Reservation (ORR) ER Program, (3) ORNL site history and characterization, and (4) history and characterization of Waste Area Groupings (WAGS) 1-20. This document was created to save time, effort, and money for persons and organizations drafting documents for the ER Program and to improve consistency in the documents prepared for the program. By eliminating the repetitious use of selected information about the program, this document will help reduce the time and costs associated with producing program documents. By serving as a benchmark for selected information about the ER Program, this reference will help ensure that information presented in future documents is accurate and complete.

  16. Melton Valley Storage Tanks Capacity Increase Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  17. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ``doses`` of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases.

  18. Technical background information for the environmental and safety report, Volume 4: White Oak Lake and Dam

    Energy Technology Data Exchange (ETDEWEB)

    Oakes, T.W.; Kelly, B.A.; Ohnesorge, W.F.; Eldridge, J.S.; Bird, J.C.; Shank, K.E.; Tsakeres, F.S.

    1982-03-01

    This report has been prepared to provide background information on White Oak Lake for the Oak Ridge National Laboratory Environmental and Safety Report. The paper presents the history of White Oak Dam and Lake and describes the hydrological conditions of the White Oak Creek watershed. Past and present sediment and water data are included; pathway analyses are described in detail.

  19. Tiger team assessment of the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1990-02-01

    This document contains findings identified during the Tiger Team Compliance Assessment of the Department of Energy's (DOE's) Y-12 Plant in Oak Ridge, Tennessee. The Y-12 Plant Tiger Team Compliance Assessment is comprehensive in scope. It covers the Environmental, Safety, and Health (including Occupational Safety and Health Administration (OSHA) compliance), and Management areas and determines the plant's compliance with applicable federal (including DOE), state, and local regulations and requirements. 4 figs., 12 tabs.

  20. 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.

  1. A comparison of change detection measurements using object-based and pixel-based classification methods on western juniper dominated woodlands in eastern Oregon

    Directory of Open Access Journals (Sweden)

    Ryan G. Howell

    2017-03-01

    Full Text Available Encroachment of pinyon (Pinus spp and juniper (Juniperus spp. woodlands in western North America is considered detrimental due to its effects on ecohydrology, plant community structure, and soil stability. Management plans at the federal, state, and private level often include juniper removal for improving habitat of sensitive species and maintaining sustainable ecosystem processes. Remote sensing has become a useful tool in determining changes in juniper woodland structure because of its uses in comparing archived historic imagery with newly available multispectral images to provide information on changes that are no longer detectable by field measurements. Change in western juniper (J. occidentalis cover was detected following juniper removal treatments between 1995 and 2011 using panchromatic 1-meter NAIP and 4-band 1-meter NAIP imagery, respectively. Image classification was conducted using remotely sensed images taken at the Roaring Springs Ranch in southeastern Oregon. Feature Analyst for ArcGIS (object-based extraction and a supervised classification with ENVI 5.2 (pixel-based extraction were used to delineate juniper canopy cover. Image classification accuracy was calculated using an Accuracy Assessment and Kappa Statistic. Both methods showed approximately a 76% decrease in western juniper cover, although differing in total canopy cover area, with object-based classification being more accurate. Classification results for the 2011 imagery were much more accurate (0.99 Kappa statistic because of its low juniper density and the presence of an infrared band. The development of methods for detecting change in juniper cover can lead to more accurate and efficient data acquisition and subsequently improved land management and monitoring practices. These data can subsequently be used to assess and quantify juniper invasion and succession, potential ecological impacts, and plant community resilience.

  2. Site descriptions of environmental restoration units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, P.L.; Legeay, A.J.; Pesce, D.S.; Stanley, A.M.

    1995-11-01

    This report, Site Descriptions of Environmental Restoration Units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee, is being prepared to assimilate information on sites included in the Environmental Restoration (ER) Program of the K-25 Site, one of three major installations on the Oak Ridge Reservation (ORR) built during World War III as part of the Manhattan Project. The information included in this report will be used to establish program priorities so that resources allotted to the K-25 ER Program can be best used to decrease any risk to humans or the environment, and to determine the sequence in which any remedial activities should be conducted. This document will be updated periodically in both paper and Internet versions. Units within this report are described in individual data sheets arranged alphanumerically. Each data sheet includes entries on project status, unit location, dimensions and capacity, dates operated, present function, lifecycle operation, waste characteristics, site status, media of concern, comments, and references. Each data sheet is accompanied by a photograph of the unit, and each unit is located on one of 13 area maps. These areas, along with the sub-area, unit, and sub-unit breakdowns within them, are outlined in Appendix A. Appendix B is a summary of information on remote aerial sensing and its applicability to the ER program.

  3. Oak Ridge Reservation environmental report for 1989

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-10-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1989. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1989 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Vol. 2. The tables in Vol. 2 are addressed in Vol. 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Vol. 1. 16 figs., 194 tabs.

  4. Oak Ridge Reservation Environmental report for 1990

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A.R. (ed.)

    1991-09-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1990. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1990 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Vol. 2. The tables in Vol. 2 are addressed in Vol. 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Vol. 1.

  5. Accumulation of Glycoconjugates of 3-Methyl-4-hydroxyoctanoic Acid in Fruits, Leaves, and Shoots of Vitis vinifera cv. Monastrell following Foliar Applications of Oak Extract or Oak Lactone.

    Science.gov (United States)

    Pardo-Garcia, Ana I; Wilkinson, Kerry L; Culbert, Julie A; Lloyd, Natoiya D R; Alonso, Gonzalo L; Salinas, M Rosario

    2015-05-13

    Grapevines are capable of absorbing volatile compounds present in the vineyard during the growing season, and in some cases, volatiles have been found to accumulate in fruits or leaves in glycoconjugate forms, that is, with one or more sugar moieties attached. The presence of oak lactone in wine is usually attributable to oak maturation, but oak lactone has been detected in wines made with fruit from grapevines treated with oak extract or oak lactone. This study investigated the accumulation of glycoconjugates of 3-methyl-4-hydroxyoctanoic acid (i.e., the ring-opened form of oak lactone) in the fruits, leaves, and shoots of Monastrell grapevines following foliar application of either oak extract or oak lactone at approximately 7 days postveraison. Fruits, leaves, and shoots were collected at three different time points, including at maturity. The oak lactone content of fruit was determined by gas chromatography-mass spectrometry, with declining concentrations observed in fruit from grapevines treated with oak lactone with ripening. The concentrations of a β-d-glucopyranoside of 3-methyl-4-hydroxyoctanoic acid in fruits, leaves, and shoots was determined by liquid chromatography-tandem mass spectrometry, with the highest oak lactone glucoside levels observed in leaves of grapevines treated with oak lactone. A glucose-glucose disaccharide was also tentatively identified. These results demonstrate both ring-opening and glycosylation of oak lactone occurred after experimental treatments were imposed.

  6. Screening of contaminants in Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Comparison of seasonal habitat selection between threatened woodland caribou ecotypes in central British Columbia

    Directory of Open Access Journals (Sweden)

    Elena S. Jones

    2007-04-01

    Full Text Available Woodland caribou (Rangifer tarandus caribou in British Columbia have been classified into ecotypes based on differences in use of habitat in winter. Although recovery planning focuses on ecotypes, habitat use and selection varies within ecotypes. Our objectives were to compare habitat use and selection among previously identified woodland caribou herds at the transition zone between northern (Moberly, Quintette, and Kennedy herds and mountain (Parsnip herd ecotypes in central British Columbia. We developed selection models for each herd in spring, calving, summer/fall, early and late winter. Topographic models best predicted selection by most herds in most seasons, but importance of vegetation-cover was highlighted by disproportionate use of specific vegetation-cover types by all caribou herds (e.g., in early winter, 75% of Kennedy locations were in pine-leading stands, 84% of Parsnip locations were in fir and fir-leading stands, and 87 and 96% of locations were in alpine for the Moberly and Quintette herds, respectively. Using a combination of GPS and VHF radio-collar locations, we documented some spatial overlap among herds within the year, but use of vegetation-cover types and selection of elevations, aspects, and vegetation-cover types differed among herds and within ecotypes in all seasons. Habitat use and selection were most similar between the two northern-ecotype herds residing on the eastern side of the Rocky Mountains. This research indicates that habitat use and selection by caribou herds in all seasons is more variable than ecotype classifications suggest and demonstrates the value of undertaking herd-specific mapping of critical habitat for woodland caribou.

  8. 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.

  9. Simulating range-wide population and breeding habitat dynamics for an endangered woodland warbler in the face of uncertainty

    Science.gov (United States)

    Adam Duarte,; Hatfield, Jeffrey; Todd M. Swannack,; Michael R. J. Forstner,; M. Clay Green,; Floyd W. Weckerly,

    2015-01-01

    Population viability analyses provide a quantitative approach that seeks to predict the possible future status of a species of interest under different scenarios and, therefore, can be important components of large-scale species’ conservation programs. We created a model and simulated range-wide population and breeding habitat dynamics for an endangered woodland warbler, the golden-cheeked warbler (Setophaga chrysoparia). Habitat-transition probabilities were estimated across the warbler's breeding range by combining National Land Cover Database imagery with multistate modeling. Using these estimates, along with recently published demographic estimates, we examined if the species can remain viable into the future given the current conditions. Lastly, we evaluated if protecting a greater amount of habitat would increase the number of warblers that can be supported in the future by systematically increasing the amount of protected habitat and comparing the estimated terminal carrying capacity at the end of 50 years of simulated habitat change. The estimated habitat-transition probabilities supported the hypothesis that habitat transitions are unidirectional, whereby habitat is more likely to diminish than regenerate. The model results indicated population viability could be achieved under current conditions, depending on dispersal. However, there is considerable uncertainty associated with the population projections due to parametric uncertainty. Model results suggested that increasing the amount of protected lands would have a substantial impact on terminal carrying capacities at the end of a 50-year simulation. Notably, this study identifies the need for collecting the data required to estimate demographic parameters in relation to changes in habitat metrics and population density in multiple regions, and highlights the importance of establishing a common definition of what constitutes protected habitat, what management goals are suitable within those protected

  10. 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 -based identification of the components of each vegetation stratum as well as the measuring of the actual maximum height of each stratum. Phenological changes were also monitored over the four different seasons in a year and recorded in a form of photographs taken... As for phenology, the results of the analysis revealed that the woodland in the study area goes through four distinctive changes that correspond with the four seasons in a year. In summer, Brachystegia spiciformis is in full green canopy. Flowering starts...

  11. Taphonomic alterations by the rodent species woodland vole (Microtus pinetorum) upon human skeletal remains.

    Science.gov (United States)

    Pokines, James T

    2015-12-01

    This forensic case report describes the taphonomic effects of woodland vole (Microtus pinetorum) upon a set of skeletonized human remains recovered in Massachusetts, USA. Remains of an individual of this rodent species were discovered where it had been nesting inside the human cranium. Fine, parallel grooves indicative of small rodent gnawing were noted on multiple postcranial elements, and all isolated grooves were consistent in size with the incisors of this species. Other taphonomic alterations to these remains include some gnawing damage and dispersal by large carnivores. This case represents the first report of this rodent species affecting human remains. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Transpiration and hydraulic strategies in a piñon-juniper woodland.

    Science.gov (United States)

    West, A G; Hultine, K R; Sperry, J S; Bush, S E; Ehleringer, J R

    2008-06-01

    Anthropogenic climate change is likely to alter the patterns of moisture availability globally. The consequences of these changes on species distributions and ecosystem function are largely unknown, but possibly predictable based on key ecophysiological differences among currently coexisting species. In this study, we examined the environmental and biological controls on transpiration from a piñon-juniper (Pinus edulis-Juniperus osteosperma) woodland in southern Utah, USA. The potential for climate-change-associated shifts in moisture inputs could play a critical role in influencing the relative vulnerabilities of piñons and junipers to drought and affecting management decisions regarding the persistence of this dominant landscape type in the Intermountain West. We aimed to assess the sensitivity of this woodland to seasonal variations in moisture and to mechanistically explain the hydraulic strategies of P. edulis and J. osteosperma through the use of a hydraulic transport model. Transpiration from the woodland was highly sensitive to variations in seasonal moisture inputs. There were two distinct seasonal pulses of transpiration: a reliable spring pulse supplied by winter-derived precipitation, and a highly variable summer pulse supplied by monsoonal precipitation. Transpiration of P. edulis and J. osteosperma was well predicted by a mechanistic hydraulic transport model (R2 = 0.83 and 0.92, respectively). Our hydraulic model indicated that isohydric regulation of water potential in P. edulis minimized xylem cavitation during drought, which facilitated drought recovery (94% of pre-drought water uptake) but came at the cost of cessation of gas exchange for potentially extended periods. In contrast, the anisohydric J. osteosperma was able to maintain gas exchange at lower water potentials than P. edulis but experienced greater cavitation over the drought and showed a lesser degree of post-drought recovery (55% of pre-drought uptake). As a result, these species

  13. Simultaneous assimilation of satellite and eddy covariance data for improving terrestrial water and carbon simulations at a semi-arid woodland site in Botswana

    NARCIS (Netherlands)

    Kato, T.; Knorr, W.; Scholtze, M.; Veenendaal, E.M.; Kaminski, T.; Kattge, J.; Gobron, N.

    2013-01-01

    Terrestrial productivity in semi-arid woodlands is strongly susceptible to changes in precipitation, and semi-arid woodlands constitute an important element of the global water and carbon cycles. Here, we use the Carbon Cycle Data Assimilation System (CCDAS) to investigate the key parameters control

  14. 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

  15. Does the structure of wood contribute to understanding the oaks decline phenomenon?

    Directory of Open Access Journals (Sweden)

    Mirela Tulik

    2014-04-01

    Full Text Available Vascular cambium is a meristematic tissue which produces wood centriphugaly and phloem centripetaly. In the structure of wood and phloem, data concerning developmental processes taking place in the cambium is recorded. The history of the cambium is encoded in the dimensions, numbers and arrangements of the wood and phloem cells. For investigations, the wood is usually preferred because it is durable and such data could remain unchanged for centuries, whereas in the phloem due to distorted processes, it deranges after a few years. In broadleaves, the wood is composed of vessels, tracheids, fibers and parenchyma cells. The process of the wood formation consists of the cambial cell derivatives expansion, lignification of its walls and programmed cell death. Since the seventies of the nineteenth century, the process of declining oaks taking place in Europe on a regular basis has been observed. Oak decline is a complex process that involves interactions of both biotic and abiotic factors leading to increased trees mortality. The main goal of the studies is the examination of the structure of wood in declining oaks (Quercus robur L. in respect to physiological (conductive role of this tissue. It is known that on the level of the wood structure, water transport efficiency depends on the diameter of vessels - the main elements of the hydraulic conductivity system. Any reduction of the vessels lumen causes the reduction of the water transport to the organs of the trees body and, therefore, influences organisms survival rate. Anatomical analyses were carried out on wood samples (comprising all annual rings formed during the 30-40 years life of the analyzed trees collected at breast height from the main stem of healthy, weakened and dead oaks. The anatomical traits of the wood like as the width of the annual increments, the diameter and density of early wood vessels were measured. The results which are described in the paper by Tulik (2014 revealed that

  16. Technical Evaluation of Oak Ridge Filter Test Facility

    CERN Document Server

    Kriskovich, J R

    2002-01-01

    Two evaluations of the Oak Ridge Department of Energy (DOE) Filter Test Facility (FTF) were performed on December 11 and 12, 2001, and consisted of a quality assurance and a technical evaluation. This report documents results of the technical evaluation.

  17. Baskett Slough - Oregon White Oak Restoration- North Butte

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Willamette Valley National Wildlife Refuge Complex (WVNWRC) holds some of the largest and best examples of Oregon white oak habitat remaining in the Valley....

  18. Narrative report Oak Orchard National Wildlife Refuge: January - April, 1959

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from January through April of 1959. The report begins by summarizing...

  19. Narrative report Oak Orchard National Wildlife Refuge: September - December, 1960

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from September through December of 1960. The report begins by...

  20. Narrative report Oak Orchard National Wildlife Refuge: September - December, 1959

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from September through December of 1959. The report begins by...

  1. Big Oaks National Wildlife Refuge : Interim Plans : 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This interim plan for Big Oaks National Wildlife Refuge cover an interim comprehensive conservation plan, a hunting and fishing plan and an interim compatibility...

  2. Recognizing the Toxicodendrons (poison ivy, poison oak, and poison sumac).

    Science.gov (United States)

    Guin, J D; Gillis, W T; Beaman, J H

    1981-01-01

    Poison ivy, poison oak, and poison sumac are now classified in the genus Toxicodendron which is readily distinguished from Rhus. In the United States, there are two species of poison oak, Toxicodendron diversilobum (western poison oak) and Toxicodendron toxicarium (eastern poison oak). There are also two species of poison ivy, Toxicodendron rydbergii, a nonclimbing subshrub, and Toxicodendron radicans, which may be either a shrub or a climbing vine. There are nine subspecies of T. radicans, six of which are found in the United States. One species of poison sumac, Toxicodendron vernix, occurs in the United States. Distinguishing features of these plants and characteristics that separate Toxicodendron from Rhus are outlined in the text and illustrated in color plates.

  3. Narrative report Oak Orchard National Wildlife Refuge: September - December, 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from September through December of 1962. The report begins by...

  4. Narrative report Oak Orchard National Wildlife Refuge: May - August, 1963

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from May through August of 1963. The report begins by summarizing the...

  5. Narrative report Oak Orchard National Wildlife Refuge: May - August, 1959

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from May through August of 1959. The report begins by summarizing the...

  6. Narrative report Oak Orchard National Wildlife Refuge: September - December, 1963

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from September through December of 1963. The report begins by...

  7. Narrative report Oak Orchard National Wildlife Refuge: May - August, 1960

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from May through August of 1960. The report begins by summarizing the...

  8. Narrative report Oak Orchard National Wildlife Refuge: January - April, 1960

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from January through April of 1960. The report begins by summarizing...

  9. Narrative report Oak Orchard National Wildlife Refuge: May - August, 1961

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from May through August of 1961. The report begins by summarizing the...

  10. Narrative report Oak Orchard National Wildlife Refuge: January - April, 1961

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from January through April of 1961. The report begins by summarizing...

  11. Narrative report Oak Orchard National Wildlife Refuge: January - April, 1963

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from January through April of 1963. The report begins by summarizing...

  12. Narrative report Oak Orchard National Wildlife Refuge: January - April, 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from January through April of 1962. The report begins by summarizing...

  13. Narrative report Oak Orchard National Wildlife Refuge: September - December, 1961

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from September through December of 1961. The report begins by...

  14. Narrative report Oak Orchard National Wildlife Refuge: May - August, 1962

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Oak Orchard National Wildlife Refuge outlines Refuge accomplishments from May through August of 1962. The report begins by summarizing the...

  15. Big Oaks National Wildlife Refuge : Interim Public Access Plan : 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This interim plan covers public access for Big Oaks National Wildlife Refuge. Sections include introduction, safety briefing protocols, entry procedure, types of...

  16. 60 years of great science [Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-01-01

    This issue highlights Oak Ridge National Laboratory's contributions in more than 30 areas of research and related activities during the past 60 years and provides glimpses of current activities that are carrying on this heritage.

  17. Redescrição de Nomimoscolex admonticellia (Woodland, comb.n. (Cestoda: Proteocephalidea, parasito de Pinirampus pirinampu (Spix, um siluriforme de água doce Redescription of Nomimoscolex admonticellia (Woodland, comb.n (Cestoda: Proteocephalidea parasite of Pinirampus pirinampu (Spix, a freshwater siluriform fish

    Directory of Open Access Journals (Sweden)

    Amilcar Arandas Rego

    1992-01-01

    Full Text Available The Monticelliidae species, Nomimoscolex admonticellia (Woodland, 1934, comb.n., parasite of Pinirampus pirinampu (Spix, 1829 a freshwater siluriform fish, is redescribed. This species is the type of the genus Myzophorus Woodland, 1934. The authors discuss the validity of this genus and propose its suppression. Their species are transferred to Nomimoscolex (Zigobothriinae whose diagnose is modified to include: N. admonticellia, comb.n., N. pirarara (Woodland, 1935, comb.n. and N. woodlandi (Rego, 1984, comb.n.

  18. The Oak Ridge Reservation Annual Site Environmental Report Summary, 2007

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-02-28

    The Oak Ridge Reservation Annual Site Environmental Report is prepared and published each year to inform the public of the environmental activities that take place on the reservation and in the surrounding areas. It is written to comply with DOE Order 231.1A, Environment, Safety, and Health Reporting. This document has been prepared to present the highlights of the Oak Ridge Reservation Annual Site Environmental Report 2007 in an easy-to-read, summary format.

  19. Chloroplast DNA Diversity of Oak Species in Eastern Romania

    Directory of Open Access Journals (Sweden)

    Ioan Calin MOLDOVAN

    2010-12-01

    Full Text Available The chloroplast DNA of 34 sessile oak (Quercus petraea and 27 pedunculate oak (Q. robur populations covering the entire natural distribution of the two oak species in Eastern Romania was investigated using four large regions of the chloroplast genome by PCR and RFLP technique. A total of seven chloroplast DNA haplotypes sensu lato have been observed by analysing 305 mature trees. However, due to the high resolution of the electrophoresis method a total of 22 chloroplast variants could have been detected, with new mutations and fragment combinations in two of the amplified regions: psbC/trnD and trnT/trnF. All of the haplotypes belong to the phylogenetic lineages A and E, which originate from the Balkan Peninsula. Most of genetic diversity is distributed among populations (GST=0.779. The chloroplast DNA haplotypes are shared by the two oak species. Different dispersal abilities may explain the higher value of genetic differentiation among populations in sessile oak than in pedunculate oak.

  20. Acorn Production Characteristics of Southern Appalachian Oaks: A Simple Method to Predict Within-Year Crop Size

    Science.gov (United States)

    Cathryn H. Greenberg; Bernard R. Parresol

    2000-01-01

    We examined acorn production from 1993-97 by black oak (Quercus velutina Lam.), northern red oak (Q. rubra L.), scarlet oak (Q. coccinea Muenchh.), chestnut oak (Q. prinus L.), and white oak (Q. alba L.) in the Southern Appalichians to determine how frequency of acorn...

  1. Runoff and erosion in a pinon-juniper woodland: Influence of vegetation patches

    Energy Technology Data Exchange (ETDEWEB)

    Reid, K.D.; Wilcox, B.P.; Breshears, D.D.; MacDonald, L.

    1999-12-01

    In many semiarid regions, runoff and erosion differ according to vegetation patch type. These differences, although hypothesized to fundamentally affect ecological processes, have been poorly quantified. In a semiarid pinion-juniper woodland [Pinus edulis Engelm. and Juniperus monosperma (Engelm) Sarg.] in northern New Mexico, the authors measured runoff and erosion from the three patch types that compose these woodlands: Canopy patches (those beneath woody plants), vegetated patched in intercanopy areas, and bare patches in intercanopy areas. The bare intercanopy patches exhibited the highest rates, followed by vegetated intercanopy patches and then by canopy patches. Large convective summer storms, though relatively infrequent, generated much of the runoff and most of the sediment; prolonged frontal storms were capable of generating considerable runoff but little sediment. A portion of the runoff and most of the sediment generated from bare intercanopy patches was redistributed down-slope, probably to adjacent vegetated intercanopy patches, demonstrating connectivity between these two patch types. Their results indicate that there are significant and important differences in runoff and sediment production from the three patch types; that bare intercanopy patches act as sources of both water and sediment for the vegetated intercanopy patches; and that the transfer of water and sediment at small scales is both frequent enough and substantial enough to be considered ecologically significant.

  2. National recovery strategy for woodland caribou (Rangifer tarandus caribou, boreal population, in Canada

    Directory of Open Access Journals (Sweden)

    Dave Hervieux

    2007-04-01

    Full Text Available Recovery planning for the boreal population of woodland caribou is a complex task, spanning eight Canadian provinces and territories. To accommodate unique situations across the country, recovery planning for this Species at Risk Act-listed threatened species is occurring at both provincial/ territorial and national levels. The national recovery strategy strives to identify nationally important issues and provide direction for provinces and territories as they plan and implement boreal caribou recovery within their jurisdictions. The national vision is to conserve and recover boreal caribou and their habitat across Canada. Specific goals are to: 1 Prevent extirpation of local boreal caribou populations from all existing caribou ranges; and 2 Maintain or enhance local boreal caribou populations at or to self-sustaining levels within all existing caribou ranges; and 3 Maintain or enhance boreal caribou habitat to support self-sustaining local populations. Nineteen broad national approaches are identified. These approaches include items relating to: habitat planning and management, caribou population monitoring and management, management of human-caused mortality, management of other wildlife species, consideration of government legislation and policy,promotion of stewardship and public outreach, and research. Specific outcomes are provided for each stated recovery approach. For more information on Canada's national recovery strategy for the boreal population of woodland caribou please see www.speciesatrisk.gc.ca/recovery/default_e.cfm

  3. Detection of soil erosion within pinyon-juniper woodlands using Thematic Mapper (TM) data

    Science.gov (United States)

    Price, Kevin P.

    1993-01-01

    Multispectral measurements collected by Landsat Thematic Mapper (TM) were correlated with field measurements, direct soil loss estimates, and Universal Soil Loss Equation (USLE) estimates to determine the sensitivity of TM data to varying degrees of soil erosion in pinyon-juniper woodland in central Utah. TM data were also evaluated as a predictor of the USLE Crop Management C factor for pinyon-juniper woodlands. TM spectral data were consistently better predictors of soil erosion factors than any combination of field factors. TM data were more sensitive to vegetation variations than the USLE C factor. USLE estimates showed low annual rates of erosion which varied little among the study sites. Direct measurements of rate of soil loss using the SEDIMENT (Soil Erosion DIrect measureMENT) technique, indicated high and varying rates of soil loss among the sites since tree establishment. Erosion estimates from the USLE and SEDIMENT methods suggest that erosion rates have been severe in the past, but because significant amounts of soil have already been eroded, and the surface is now armored by rock debris, present erosion rates are lower. Indicators of accelerated erosion were still present on all sites, however, suggesting that the USLE underestimated erosion within the study area.

  4. Auxin biosynthesis by the YUCCA6 flavin monooxygenase gene in woodland strawberry.

    Science.gov (United States)

    Liu, Hong; Xie, Wei-Fa; Zhang, Ling; Valpuesta, Victoriano; Ye, Zheng-Wen; Gao, Qing-Hua; Duan, Ke

    2014-04-01

    Auxin has been regarded as the main signal molecule coordinating the growth and ripening of fruits in strawberry, the reference genomic system for Rosaceae. The mechanisms regulating auxin biosynthesis in strawberry are largely elusive. Recently, we demonstrated that two YUCCA genes are involved in flower and fruit development in cultivated strawberry. Here, we show that the woodland strawberry (Fragaria vesca L.) genome harbors nine loci for YUCCA genes and eight of them encode functional proteins. Transcription pattern in different plant organs was different for all eight FvYUCs. Functionality of the FvYUC6 gene was studied in transgenic strawberry overexpressing FvYUC6, which showed typical high-auxin phenotypes. Overexpression of FvYUC6 also delayed flowering and led to complete male sterility in F. vesca. Additionally, specific repression of FvYUC6 expression by RNA interference significantly inhibited vegetative growth and reduced plant fertility. The development of leaves, roots, flowers, and fruits was greatly affected in FvYUC6-repressed plants. Expression of a subset of auxin-responsive genes was well correlated with the changes of FvYUC6 transcript levels and free indole-3-acetic acid levels in transgenic strawberry. These observations are consistent with an important role of FvYUC6 in auxin synthesis, and support a main role of the gene product in vegetative and reproductive development in woodland strawberry.

  5. Modelling soil moisture for a grassland and a woodland site in south-east England

    Directory of Open Access Journals (Sweden)

    E. Blyth

    2002-01-01

    Full Text Available This paper describes a comparison between two soil moisture prediction models. One is MORECS (Met Office Rainfall and Evaporation Calculation Scheme, the Met Office soil moisture model that is used by agriculture, flood modellers and weather forecasters to initialise their models. The other is MOSES (Met Office Surface Exchange Scheme, modified with a runoff generation module. The models are made compatible by increasing the vegetation information available to MOSES. Both models were run with standard parameters and were driven using meteorological observations at Wallingford (1995-1997. Detailed soil moisture measurements were available at a grassland site and a woodland site in this area. The comparison between the models and the observed soil moisture indicated that, for the grassland site, MORECS dried out too quickly in the spring and, for the woodland site, was too wet. Overall, the performance of MOSES was superior. The soil moisture predicted by the new, modified MOSES will be included as a product of Nimrod - the 5 km x 5km gridded network of observed meteorological data across the UK. Keywords: Soil moisture, model, observation, field capacity

  6. 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.

  7. Mapping forest stand complexity for woodland caribou habitat assessment using multispectral airborne imagery

    Science.gov (United States)

    Zhang, W.; Hu, B.; Woods, M.

    2014-11-01

    The decline of the woodland caribou population is a result of their habitat loss. To conserve the habitat of the woodland caribou and protect it from extinction, it is critical to accurately characterize and monitor its habitat. Conventionally, products derived from low to medium spatial resolution remote sensing data, such as land cover classification and vegetation indices are used for wildlife habitat assessment. These products fail to provide information on the structure complexities of forest canopies which reflect important characteristics of caribou's habitats. Recent studies have employed the LiDAR system (Light Detection And Ranging) to directly retrieve the three dimensional forest attributes. Although promising results have been achieved, the acquisition cost of LiDAR data is very high. In this study, utilizing the very high spatial resolution imagery in characterizing the structural development the of forest canopies was exploited. A stand based image texture analysis was performed to predict forest succession stages. The results were demonstrated to be consistent with those derived from LiDAR data.

  8. Effects of fire and thinning on oak and other hardwood species regeneration in mixed oak forests of southeastern Ohio

    Science.gov (United States)

    Brian C. McCarthy; Matthew A. Albrecht

    2005-01-01

    We conducted a study of hardwood regeneration in the mixed oak forests of unglaciated southeastern Ohio following various silvicultural practices. Our study was conducted at three separate forests within the region.

  9. Decomposition of oak leaf litter and millipede faecal pellets in soil under temperate mixed oak forest

    Science.gov (United States)

    Tajovský, Karel; Šimek, Miloslav; Háněl, Ladislav; Šantrůčková, Hana; Frouz, Jan

    2015-04-01

    The millipedes Glomeris hexasticha (Diplopoda, Glomerida) were maintained under laboratory conditions and fed on oak leaf litter collected from a mixed oak forest (Abieto-Quercetum) in South Bohemia, Czech Republic. Every fourth day litter was changed and produced faecal pellets were separated and afterwards analysed. Content of organic carbon and C:N ratio lowered in faecal pellets as compared with consumed litter. Changes in content of chemical elements (P, K, Ca, Mg, Na) were recognised as those characteristic for the first stage of degradation of plant material. Samples of faecal pellets and oak leaf litter were then exposed in mesh bags between the F and H layers of forest soil for up to one year, subsequently harvested and analysed. A higher rate of decomposition of exposed litter than that of faecal pellets was found during the first two weeks. After 1-year exposure, the weight of litter was reduced to 51%, while that of pellets to 58% only, although the observed activity of present biotic components (algae, protozoans, nematodes; CO2 production, nitrogenase activity) in faecal pellets was higher as compared with litter. Different micro-morphological changes were observed in exposed litter and in pellets although these materials originated from the same initial sources. Comparing to intact leaf litter, another structural and functional processes occurred in pellets due to the fragmentation of plant material by millipedes. Both laboratory and field experiments showed that the millipede faecal pellets are not only a focal point of biodegradation activity in upper soil layers, but also confirmed that millipede feces undergo a slower decomposition than original leaf litter.

  10. Project plan for the Background Soil Characterization Project on the Oak Ridge Reservation, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    The Background Soil characterization Project (BSCP) will provide background concentration levels of selected metals, organic compounds, and radionuclides in soils from uncontaminated on-site areas at the Oak Ridge Reservation (ORR), and off-site in the western part of Roane County and the eastern part of Anderson County. The BSCP will establish a database, recommend how to use the data for contaminated site assessment, and provide estimates of the potential human health and environmental risks associated with the background level concentrations of potentially hazardous constituents.

  11. Data Sharing Report Characterization of Isotope Row Facilities Oak Ridge National Laboratory Oak Ridge TN

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Phyllis C. [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

    2013-12-12

    The U.S. Department of Energy (DOE) Oak Ridge Office of Environmental Management (EM-OR) requested that Oak Ridge Associated Universities (ORAU), working under the Oak Ridge Institute for Science and Education (ORISE) contract, provide technical and independent waste management planning support using funds provided by the American Recovery and Reinvestment Act (ARRA). Specifically, DOE EM-OR requested ORAU to plan and implement a survey approach, focused on characterizing the Isotope Row Facilities located at the Oak Ridge National Laboratory (ORNL) for future determination of an appropriate disposition pathway for building debris and systems, should the buildings be demolished. The characterization effort was designed to identify and quantify radiological and chemical contamination associated with building structures and process systems. The Isotope Row Facilities discussed in this report include Bldgs. 3030, 3031, 3032, 3033, 3033A, 3034, 3036, 3093, and 3118, and are located in the northeast quadrant of the main ORNL campus area, between Hillside and Central Avenues. Construction of the isotope production facilities was initiated in the late 1940s, with the exception of Bldgs. 3033A and 3118, which were enclosed in the early 1960s. The Isotope Row facilities were intended for the purpose of light industrial use for the processing, assemblage, and storage of radionuclides used for a variety of applications (ORNL 1952 and ORAU 2013). The Isotope Row Facilities provided laboratory and support services as part of the Isotopes Production and Distribution Program until 1989 when DOE mandated their shutdown (ORNL 1990). These facilities performed diverse research and developmental experiments in support of isotopes production. As a result of the many years of operations, various projects, and final cessation of operations, production was followed by inclusion into the surveillance and maintenance (S&M) project for eventual decontamination and decommissioning (D&D). The

  12. Geophysical Surveys of a Known Karst Feature, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, P.J.; Carr, B.J.; Doll, W.E.; Kaufmann, R.D.; Nyquist, J.E.

    1999-11-14

    Geophysical data were acquired at a site on the Oak Ridge Reservation, Tennessee to determine the characteristics of a mud-filled void and to evaluate the effectiveness of a suite of geophysical methods at the site. Methods that were used included microgravity, electrical resistivity, and seismic refraction. Both microgravity and resistivity were able to detect the void as well as overlying structural features. The seismic data provide bedrock depth control for the other two methods, and show other effects that are caused by the void.

  13. INDEPENDENT VERIFICATION OF THE BUILDING 3550 SLAB AT OAK RIDGE NATIONAL LABORATORY OAK RIDGE, TENNESSEE

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Phyllis C.

    2012-05-08

    The Oak Ridge Institute for Science and Education (ORISE) has completed the independent verification survey of the Building 3550 Slab. The results of this effort are provided. The objective of this verification survey is to provide independent review and field assessment of remediation actions conducted by Safety and Ecology Corporation (SEC) to document that the final radiological condition of the slab meets the release guidelines. Verification survey activities on the Building 3550 Slab that included scans, measurements, and the collection of smears. Scans for alpha, alpha plus beta, and gamma activity identified several areas that were investigated.

  14. Oak Ridge Reservation environmental report for 1990

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A.R. (ed.)

    1991-09-01

    The purpose of this report is to provide information to the public about the impact of the US Department of Energy's (DOE's) facilities located on the Oak Ridge Reservation (ORR) on the public and the environment. It describes the environmental surveillance and monitoring activities conducted at and around the DOE facilities operated by Martin Marietta Energy Systems, Inc. Preparation and publication of this report is in accordance with DOE Order 5400.1. The order specifies a publication deadline of June of the following year for each calendar year of data. The primary objective of this report is to summarize all information collected for the previous calendar year regarding effluent monitoring, environmental surveillance, and estimates of radiation and chemical dose to the surrounding population. When multiple years of information are available for a program, trends are also evaluated. The first seven sections of Volume 1 of this report address this objective. The last three sections of Volume 1 provide information on solid waste management, special environmental studies, and quality assurance programs.

  15. Drought impact on carbon and water cycling in a Mediterranean Quercus suber L. woodland during the extreme drought event in 2012

    Science.gov (United States)

    Piayda, Arndt; Dubbert, Maren; Rebmann, Corinna; Kolle, Olaf; Silva, Filipe Costa e.; Correia, Alexandra; Pereira, João S.; Werner, Christiane; Cuntz, Matthias

    2015-04-01

    Savannah-type ecosystems account for 26-30% of global gross primary productivity GPP, with water being one of the major driving factors. In Europe, savannah-type woodlands cover an area of about 1.5 million ha. Here, the recent past has shown a significant decrease in precipitation P in winter and spring as well as a decrease in total annual precipitation. Strong effects on local water balance and carbon sink strength have thus been reported due to changes in precipitation regime. The objective of this study is to quantify the impact of the extreme drought event in 2012 on the water balance, gross primary productivity and carbon sink strength of a typical Portuguese cork-oak woodland (montado) compared to the wet year of 2011. Physiological responses of the dominant tree species Quercus suber (L.) are disentangled employing combined photosynthesis and stomatal conductance modelling. Precipitation effectiveness ET/P increased from 86% in 2011 to 122% in the 2012 dry year due to deep soil or groundwater access of the Q. suber trees leaving no water for groundwater replenishment. Understorey and overstorey GPP were strongly reduced, by 53 and 28%, respectively, in 2012 compared to 2011, due to the late onset of the autumn rains in 2011 and an additional severe winter/spring drought. However, the ecosystem was still a carbon sink in both years, but with a 38% reduced sink strength under extreme drought in 2012 compared to 2011. The combined photosynthesis-stomatal conductance model yielded the best results if it was allowed to adjust photosynthetic and stomatal parameters simultaneously. If stomatal response was modelled with the Leuning approach, which allows for a different sensitivity to vapour pressure deficit, the stomatal model parameters were highly coupled. A change in either of the parameters needed to be compensated by the other to guarantee a stable sensitivity of stomatal conductance to assimilation, independent of variations in vapour pressure deficit. The

  16. Drought impact on carbon and water cycling in a Mediterranean Quercus suber L. woodland during the extreme drought event in 2012

    Directory of Open Access Journals (Sweden)

    A. Piayda

    2014-07-01

    Full Text Available Savannah-type ecosystems account for 26–30% of global gross primary productivity GPP with water being one of the major driving factors. In Europe, savannah-type woodlands cover an area of about 1.5 million ha. Here, the recent past has shown a significant decrease of precipitation P in winter and spring as well as decrease of total annual precipitation. Strong effects on local water balance and carbon sink strength have thus been reported due to changes in precipitation regime. The objective of this study is to quantify the impact of the extreme drought event in 2012 on the water balance, gross primary productivity and carbon sink strength of a typical Portuguese cork-oak woodland (montado compared to the wet year 2011. Physiological responses of the dominant tree species Quercus suber (L. are disentangled, employing combined photosynthesis and stomatal conductance modelling. Precipitation effectiveness ET / P increased from 86% in 2011 to 122% in the dry year 2012 due to deep soil or ground water access of the Q. suber trees leaving no water for ground water replenishment. Understorey and overstorey GPP were strongly reduced by 53% and 28%, respectively, in 2012 compared to 2011 due to the late onset of the autumn rains in 2011 and an additional severe winter/spring drought. However, the ecosystem was still a carbon sink in both years but with a 38% reduced sink strength under extreme drought in 2012 compared to 2011. The combined photosynthesis-stomatal conductance model yielded best results if it was allowed to adjust photosynthetic and stomatal parameters simultaneously. If stomatal response was modelled with the Leuning approach, which allows for a different sensitivity to vapour pressure deficit, the stomatal model parameters were highly coupled. A change in either of the parameters needed to be compensated by the other to guarantee a stable sensitivity of stomatal conductance to assimilation, independently from variations in vapour

  17. Changes in avian and plant communities of aspen woodlands over 12 years after livestock removal in the Northwestern Great Basin.

    Science.gov (United States)

    Earnst, Susan L; Dobkin, David S; Ballard, Jennifer A

    2012-10-01

    Riparian and quaking aspen (Populus tremuloides) woodlands are centers of avian abundance and diversity in the western United States, but they have been affected adversely by land use practices, particularly livestock grazing. In 1990, cattle were removed from a 112,500-ha national wildlife refuge in southeastern Oregon. Thereafter, we monitored changes in vegetation and bird abundance in years 1-3 (phase 1) and 10-12 (phase 2) in 17 riparian and 9 snow-pocket aspen plots. On each 1.5-ha plot, we sampled vegetation in 6 transects. Three times during each breeding season, observers recorded all birds 50 m to each side of the plot's 150-m centerline for 25 minutes. We analyzed data with multivariate analysis of variance and paired t tests with p values adjusted for multiple comparisons. In both periods, riparian and snow-pocket aspen produced extensive regeneration of new shoots (stems/ha and 7079 stems/ha, respectively). By phase 2, a 64% increase in medium-diameter trees in riparian stands indicated successful recruitment into the overstory, but this pattern was not seen in snow-pocket stands, where the density of trees was over 2 times greater. By phase 2 in riparian and snow-pocket stands, native forb cover had increased by 68% and 57%, respectively, mesic shrub cover had increased by 29% and 58%, and sagebrush cover had decreased by 24% and 31%. Total avian abundance increased by 33% and 39% in riparian and snow-pocket aspen, respectively, ground or understory nesters increased by 133% and 67% and overstory nesters increased by 34% and 33%. Similarly, ground or understory foragers increased by 25% and 32%, aerial foragers by 55% and 57%, and overstory foragers by 66% and 43%. We interpreted the substantial regeneration of aspen shoots, increased densities of riparian forbs and shrubs, and increased avian abundances as a multitrophic-level response to the total removal of livestock and as substantial movement toward recovery of biological integrity.

  18. Wild Harvests from Scottish Woodlands Social, cultural and economic values of contemporary non-timber forest products

    Science.gov (United States)

    Marla Emery; Suzanne Martin; Alison Dyke; Alison Dyke

    2006-01-01

    More than 30 people were interviewed about the wild edibles, medicinals, and craft materials they collect and the part that collecting plays in their lives as part of the Wild Harvests from Scottish Woodlands project. Interviews were conducted in autumn 2004. Collecting non-timber forest products (NTFPs) is a source of joy and satisfaction for many of those interviewed...

  19. Current forest and woodland carbon storage and flux in California: An estimate for the 2010 statewide assessment

    Science.gov (United States)

    Timothy A. Robards

    2012-01-01

    This study used USDA Forest Service Forest Inventory and Analysis (FIA) plot data, forest growth models, wildland fire emission estimates and timber harvest data to estimate the live tree carbon storage and flux of California's forests and woodlands. Approximately 30 Tg C02e per year was estimated as the annual flux for all California forests. The forest inventory...

  20. Genetic structure in populations of an ancient woodland sedge, carex sylvatica Hudson, at a regional and local scale.

    NARCIS (Netherlands)

    Arens, P.F.P.; Bijlsma, R.J.; Westende, van 't W.P.C.; Os, van B.; Smulders, M.J.M.; Vosman, B.J.

    2005-01-01

    Wood sedge (Carex sylvatica) is a well-known ancient woodland species with a long-term persistent seed bank and a caespitose growth habit. All thirteen isolated Carex sylvatica populations in the Dutch Rhine floodplain (including the river branches Waal and IJssel) were mapped in detail and analysed

  1. Influence of soil water repellency on seedling emergence and plant survival in a burned semi-arid woodland

    Science.gov (United States)

    Despite post-fire reseeding efforts, Pinus-Juniperus (piñon-juniper) woodlands often become invaded by annual weeds that out-compete native species, degrade ecological processes, and modify natural fire patterns. In order to develop successful post-fire restoration approaches in these communities, i...

  2. Utilizing national agriculture imagery program data to estimate tree cover and biomass of pinyon and juniper woodlands

    Science.gov (United States)

    With the encroachment of pinyon (Pinus ssp.) and juniper (Juniperus ssp.) (P-J) woodlands into sagebrush steppe communities, there is an increasing interest in rapid, accurate, and inexpensive quantification methods to estimate tree canopy cover and aboveground biomass over large landscapes. The o...

  3. 林地估价技术体系研究%A Study of Technical System of Woodland Valuation

    Institute of Scientific and Technical Information of China (English)

    况水标; 尹少华; 王伟

    2011-01-01

    Within the framework of the system of integrated environmental and economic accounting,forest valuation is a new job of woodland asset management.In terms of the valuation of woodland benefits,combining with the present methods of estimating,the paper proposed a whole set of estimation methods for assessing the woodland.In the framework of the system of integrated environmental and economic accounting,it will take the time as the work of forest resources commercialization after implementation of woodland protection using.%林地估价是绿色国民经济核算体系框架背景下林地资产化管理的一项新工作。从林地的收益估算理论入手,结合现行林地和林木资产评估方法,在林地分等定级相关研究成果基础上,建立以评估林地基准地价为核心的一整套林地估价技术体系,以期为今后绿色国民经济框架下,森林资源的商品化推进工作奠定基础。

  4. Exploiting machine learning algorithms for tree species classification in a semiarid woodland using RapidEye image

    CSIR Research Space (South Africa)

    Adelabu, S

    2013-11-01

    Full Text Available in semiarid environments. In this study, we examined the suitability of 5-band RapidEye satellite data for the classification of five tree species in mopane woodland of Botswana using machine leaning algorithms with limited training samples. We performed...

  5. What lies beneath: detecting sub-canopy changes in savanna woodlands using a three-dimensional classification method

    CSIR Research Space (South Africa)

    Fisher, JT

    2015-07-01

    Full Text Available Vegetation Science What lies beneath: detecting sub-canopy changes in savanna woodlands using a three-dimensional classification method Jolene T. Fisher, Ed T.F. Witkowski, Barend F.N. Erasmus, Penelope J. Mograbi, Gregory P. Asner, Jan A.N. van...

  6. 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.

  7. Planning for and implementing an emerald ash borer-induced forest restoration program in municipal woodlands in Oakville, Ontario

    Science.gov (United States)

    Peter A. Williams; Candace. Karandiuk

    2017-01-01

    Oakville is an urban municipality with 846 ha of woodland. Management priorities are to maintain forest health, environmental health, and safety; wood production is a minor objective. The town developed a comprehensive strategy to plan for emerald ash borer (EAB; Agrilus planipennis) induced ash mortality and forest restoration. Oakville has begun...

  8. Characterization plan for the Oak Ridge National Laboratory Area-Wide Groundwater Program, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    This characterization plan has been developed as part of the U.S. Department of Energy`s (DOE`s) investigation of the Groundwater Operable Unit (GWOU) at Oak Ridge National Laboratory (ORNL) located near Oak Ridge, Tennessee. The first iteration of the characterization plan is intended to serve as a strategy document to guide subsequent GWOU remedial investigations. The plan provides a rationale and organization for groundwater data acquisition, monitoring, and remedial actions to be performed during implementation of environmental restoration activities associated with the ORNL GWOU. It is important to note that the characterization plan for the ORNL GWOU is not a prototypical work plan. As such, remedial investigations will be conducted using annual work plans to manage the work activities, and task reports will be used to document the results of the investigations. Sampling and analysis results will be compiled and reported annually with a review of data relative to risk (screening level risk assessment review) for groundwater. This characterization plan outlines the overall strategy for the remedial investigations and defines tasks that are to be conducted during the initial phase of investigation. This plan is presented with the understanding that more specific addenda to the plan will follow.

  9. 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.

  10. Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

    Directory of Open Access Journals (Sweden)

    M. V. Thomas

    2011-06-01

    Full Text Available We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE data were partitioned into gross primary productivity (GPP and ecosystem respiration (Re and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1. Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression, variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods

  11. Nest sites selection by sympatric cavity-nesting birds in miombo woodlands

    Directory of Open Access Journals (Sweden)

    Vincent R. Nyirenda

    2016-03-01

    Full Text Available Deforestation and habitat fragmentation have long been known as drivers of wildlife depletion but information on their specific impacts on cavity-nesting birds in the miombo woodlands has been lacking. A comparative study of disturbed and undisturbed sites was conducted in miombo woodlands of Zambia to assess impacts of environmental stressors on birds. Foot patrols were employed to locate, identify and count host trees and cavities for cavity-nesting birds on twenty 200 m × 200 m sample plots. Undisturbed forests had three times more cavities (the nesting sites for birds, while there were 24.6% fewer abandoned cavities in undisturbed forests than in disturbed forests. The rate of cavity abandonment was about twice as high in human-dominated forests compared to undisturbed forests (61.3% c.f. 31.9%. Cavity-nesting birds preferred larger (> 36.0 cm diameter at breast height and taller (> 5.0 m trees for nest placement, especially in human-dominated forests. A number of cavity-nesting birds preferred Brachystegia spiciformis (zebrawood, Julbernadia paniculata (munsa, Parinari curatellifolia (mobola-plum and Uapaca kirkiana (mahobohobo as host trees to 14 other miombo tree species. Arnot’s Chat (Myrmecocichla arnoti had a wider selection of host trees for cavity-nesting than the other 40 cavity-nesting birds in the study areas. Anthropogenic activities such as uncontrolled firewood collection, wild fires, logging, and land clearing for agriculture negatively influenced wood abundance and diversity, with potential implications for persistence of cavity-nesting birds. The negative impacts of anthropogenic activities could be counteracted by conservation strategies such as implementation of sound forest policies, integrative land use practices, sustainable livelihood security and stakeholders’ awareness of the need to safeguard forest-dependent avifauna.Conservation implications: This comparative study unravels specific anthropogenic impacts on

  12. High spatial resolution remote sensing imagery improves GPP predictions in disturbed, semi-arid woodlands

    Science.gov (United States)

    Krofcheck, D. J.; Eitel, J.; Vierling, L. A.; Schulthess, U.; Litvak, M. E.

    2012-12-01

    Climate across the globe is changing and consequently the productivity of terrestrial vegetation is changing with it. Gross primary productivity (GPP) is an integral part of the carbon cycle, yet challenging to measure everywhere, all the time. Efforts to estimate GPP in the context of climate change are becoming continually more salient of the need for models sensitive to the heterogeneous nature of drought and pest induced disturbance. Given the increased availability of high spatial resolution remotely sensed imagery, their use in ecosystem scale GPP estimation is becoming increasingly viable. We used a simple linear model with inputs derived from RapidEye time series data (5 meter spatial resolution) as compared to MODIS inputs (250 meter spatial resolution) to estimate GPP in intact and girdled PJ woodland to simulate drought and pest induced disturbance. An area equal to the MODIS pixels measured was aggregated using RapidEye data centered on the flux towers for comparison purposes. We generated four model runs, two using only MODIS or RapidEye spectral vegetation indices (VIs) and two using MODIS and RapidEye VIs combined at both the control and disturbed tower site. Our results suggest that for undisturbed regions, MODIS derived VIs perform better than the higher spatial resolution RapidEye VIs when a moisture sensitive index is incorporated into the model (RMSE of 17.51for MODIS vs. 22.71 for RapidEye). Modeling GPP in disturbed regions however benefits from the inclusion of high spatial resolution data (RMSE of 14.83 for MODIS vs. 14.70 for RapidEye). This discrepancy may have to do with the disparate scale of a MODIS pixel and the size of the tower fetch. Our results suggest that the best source of VI's for the modeling GPP in semi-arid woodlands depends on the level of disturbance in the landscape. Given that the rate and extent of drought and insect induced mortality events in terrestrial forests are projected to increase with our changing climate

  13. Carbon dioxide fluxes over an ancient broadleaved deciduous woodland in southern England

    Directory of Open Access Journals (Sweden)

    M. V. Thomas

    2010-05-01

    Full Text Available We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled Net Ecosystem Exchange (NEE data were partitioned into Gross Primary Productivity (GPP and ecosystem respiration (Re and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated at 21.1 Mg C ha−1 yr−1 and Re at 19.8 Mg C ha−1 yr−1; Net Ecosystem Productivity (NEP was 1.2 Mg C ha−1 yr−1. These estimates are very consistent with independent bottom-up estimates derived from Net Primary Productivity (NPP and flux chamber measurements in 2008 (GPP=20.3±1.0 Mg C ha−1 yr−1, Re=18.9±1.7 Mg C ha−1 yr−1, biomass increment =~1.4 Mg C ha−1 yr−1. Interannual variability of seasonal NEP was predominantly driven by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daytime CO2 fluxes (R2=0.53 for the summer months, interannual variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those

  14. Growing season boundary layer climate and surface exchanges in a subarctic lichen woodland

    Science.gov (United States)

    Fitzjarrald, David R.; Moore, Kathleen E.

    1994-01-01

    Between June and August 1990, observations were made at two surface micrometeorological towers near Schefferville Quebec (54 deg 52 min N, 66 deg 40.5 min W), one in a fen and one in the subarctic lichen woodland, and at four surface climatological stations. Data from these surface stations were supplemented by regular radiosonde launches. Supporting measurements of radiative components and soil temperatures allowed heat and moisture balances to be obtained at two sites. The overall surface meteorological experiment design and results of micrometeorological observations made on a 30-m tower in the lichen woodland are presented here. Seasonal variation in the heat and water vapor transport characteristics illustrate the marked effect of the late summer climatological shift in air mass type. During the first half of the summer, average valley sidewalls only 100 m high are sufficient to channel winds along the valley in the entire convective boundary layer. Channeling effects at the surface, known for some time at the long-term climate station in Schefferville, are observed both at ridge top and in the valley, possibly the response of the flow to the NW-SE orientation of valleys in the region. Diurnal surface temperature amplitude at ridge top (approximately equal to 10 C) was found to be half that observed in the valley. Relatively large differences in precipitation among these stations and the climatological station at Schefferville airport were observed and attributed to the local topography. Eddy correlation observations of the heat, moisture and momentum transports were obtained from a 30-m tower above a sparse (approximately equal to 616 stems/ha) black spruce lichen woodland. Properties of the turbulent surface boundary layer agree well with previous wind tunnel studies over idealized rough surfaces. Daytime Bowen ratios of 2.5-3 are larger than those reported in previous studies. Surface layer flux data quality was assessed by looking at the surface layer heat

  15. Growing season boundary layer climate and surface exchanges in a subarctic lichen woodland

    Science.gov (United States)

    Fitzjarrald, David R.; Moore, Kathleen E.

    1994-01-01

    Between June and August 1990, observations were made at two surface micrometeorological towers near Schefferville Quebec (54 deg 52 min N, 66 deg 40.5 min W), one in a fen and one in the subarctic lichen woodland, and at four surface climatological stations. Data from these surface stations were supplemented by regular radiosonde launches. Supporting measurements of radiative components and soil temperatures allowed heat and moisture balances to be obtained at two sites. The overall surface meteorological experiment design and results of micrometeorological observations made on a 30-m tower in the lichen woodland are presented here. Seasonal variation in the heat and water vapor transport characteristics illustrate the marked effect of the late summer climatological shift in air mass type. During the first half of the summer, average valley sidewalls only 100 m high are sufficient to channel winds along the valley in the entire convective boundary layer. Channeling effects at the surface, known for some time at the long-term climate station in Schefferville, are observed both at ridge top and in the valley, possibly the response of the flow to the NW-SE orientation of valleys in the region. Diurnal surface temperature amplitude at ridge top (approximately equal to 10 C) was found to be half that observed in the valley. Relatively large differences in precipitation among these stations and the climatological station at Schefferville airport were observed and attributed to the local topography. Eddy correlation observations of the heat, moisture and momentum transports were obtained from a 30-m tower above a sparse (approximately equal to 616 stems/ha) black spruce lichen woodland. Properties of the turbulent surface boundary layer agree well with previous wind tunnel studies over idealized rough surfaces. Daytime Bowen ratios of 2.5-3 are larger than those reported in previous studies. Surface layer flux data quality was assessed by looking at the surface layer heat

  16. 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.

  17. 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.

  18. Oak Ridge National Laboratory Core Competencies

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, J.B.; Anderson, T.D.; Berven, B.A.; Hildebrand, S.G.; Hartman, F.C.; Honea, R.B.; Jones, J.E. Jr.; Moon, R.M. Jr.; Saltmarsh, M.J.; Shelton, R.B. [and others

    1994-12-01

    A core competency is a distinguishing integration of capabilities which enables an organization to deliver mission results. Core competencies represent the collective learning of an organization and provide the capacity to perform present and future missions. Core competencies are distinguishing characteristics which offer comparative advantage and are difficult to reproduce. They exhibit customer focus, mission relevance, and vertical integration from research through applications. They are demonstrable by metrics such as level of investment, uniqueness of facilities and expertise, and national impact. The Oak Ridge National Laboratory (ORNL) has identified four core competencies which satisfy the above criteria. Each core competency represents an annual investment of at least $100M and is characterized by an integration of Laboratory technical foundations in physical, chemical, and materials sciences; biological, environmental, and social sciences; engineering sciences; and computational sciences and informatics. The ability to integrate broad technical foundations to develop and sustain core competencies in support of national R&D goals is a distinguishing strength of the national laboratories. The ORNL core competencies are: 9 Energy Production and End-Use Technologies o Biological and Environmental Sciences and Technology o Advanced Materials Synthesis, Processing, and Characterization & Neutron-Based Science and Technology. The distinguishing characteristics of each ORNL core competency are described. In addition, written material is provided for two emerging competencies: Manufacturing Technologies and Computational Science and Advanced Computing. Distinguishing institutional competencies in the Development and Operation of National Research Facilities, R&D Integration and Partnerships, Technology Transfer, and Science Education are also described. Finally, financial data for the ORNL core competencies are summarized in the appendices.

  19. Estimating Arrival Numbers for Informal Recreation: A Geographical Approach and Case Study of British Woodlands

    Directory of Open Access Journals (Sweden)

    Marije Schaafsma

    2010-02-01

    Full Text Available This paper describes a novel methodology for generating models of demand for informal outdoor recreation. We analyze visitor data from multiple forest sites across Great Britain. We introduce a wide range of variables typically omitted from most economic demand models of recreation. These include on-site characteristics, and off-site locational drivers of visitation including substitute and complement availability. A Poisson multilevel model is used to model visitor counts, and the methodology is applied to a dataset of more than 10,000 visits to open-access woodland sites. Results confirm it identifies a broader range of demand drivers than previously observed. The use of nationally available explanatory variables enhances the transferability and hence general applicability of the methodology.

  20. Volume and aboveground biomass models for dry Miombo woodland in Tanzania

    DEFF Research Database (Denmark)

    Mwakalukwa, Ezekiel Edward; Meilby, Henrik; Treue, Thorsten

    2014-01-01

    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=31), and trees and shrubs combined (44 species, n=104). Applied...... 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....