Carbon and nitrogen distribution in oak-hickory forests distributed along a productivity gradient

Energy Technology Data Exchange (ETDEWEB)

Reber, R.T.; Kaczmarek, D.J.; Pope, P.E.; Rodkey, K.S. [Purdue Univ., West Lafayette, IN (United States)

1993-12-31

Biomass, carbon and nitrogen pools were determined for oak-hickory forests of varying productivity. Little information of this type is available for the central hardwood region. Six oak-hickory dominated forests were chosen to represent a range in potential site productivity as influenced by soil type, amount of recyclable nutrients and available water. Biomass, carbon and nitrogen storage were determined for the following components: above ground standing biomass, fine root biomass, forest floor organic layers and litterfall. As site sequestered at each site was dependent more on the amount of living biomass at each site Litterfall, to some extent, increased with increasing site productivity. As potential site productivity decreased, total fine root biomass increased. The data suggest that as site quality decreased fine root production and turnover may become as important in nutrient cycling as annual litterfall.

Relative nitrogen mineralization and nitrification potentials in relation to soil chemistry in oak forest soils along a historical deposition gradient

Science.gov (United States)

Ralph E. J. Boerner; Elaine Kennedy Sutherland

1996-01-01

This study quantified soil nutrient status and N mineralization/nitrification potentials in soils of oak-dominated, unmanaged forest stands in seven USDA Forest Service experimental forests (EF) ranging along a historical and current acidic deposition gradient from southern Illinois to central West Virginia.

A dendrochronological analysis of a disturbance-succession model for oak-pine forests of the Appalachian Mountains, USA

Science.gov (United States)

Patrick H. Brose; Thomas A. Waldrop

2010-01-01

Disturbance-succession models describe the relationship between the disturbance regime and the dominant tree species of a forest type. Such models are useful tools in ecosystem management and restoration, provided they are accurate. We tested a disturbance-succession model for the oak-pine (Quercus spp. - Pinus spp.) forests of the...

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

Science.gov (United States)

Letty B. Brown; Barbara Allen-Diaz

2006-01-01

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

The macrofungal diversity and community of Atlantic oak (Quercus petraea and Q. robur) forests in Ireland

OpenAIRE

Harrington, Thomas J.; O’Hanlon, Richard

2012-01-01

The oak species Quercus petraea and Q. Robur are dominant canopy tree species of native deciduous forests in Ireland and coastal regions of Western Europe. These forests are typically plant species-rich, and can also have a rich fungal flora. This survey examined macrofungi found in five native oak sites across Ireland over three years. Overall, 94 macrofungal species belonging to 39 genera were discovered with Mycena, Lactarius, Russula and Cortinarius the most species-rich genera. The speci...

Sapflow-Based Stand Transpiration in a Semiarid Natural Oak Forest on China’s Loess Plateau

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Mei-Jie Yan

2016-10-01

Full Text Available The semi-arid region of China’s Loess Plateau is characterized by fragile ecosystems and a shortage of water resources. The major natural forest type in this region is the secondary forest with the flora dominated by the Liaodong oak (Quercus liaotungensis Koidz.. To understand its transpiration water use in relation to environmental factors, we applied Granier-type thermal dissipation probes to monitor stem sap flows of 21 sample trees, representing different classes of diameter at breast height in a permanent plot. The stem- and stand-scale transpiration values during the 2008–2010 growing seasons were estimated using measurements of sap flux densities and corresponding sapwood areas. The dominant factors affecting stand-scale transpiration varied with time scales. Daily stand transpiration correlated with daily solar radiation and daytime average vapor pressure deficit. Seasonal and interannual changes in stand transpiration were closely related to leaf area index (LAI values. No obvious relationship was observed between monthly stand transpiration and soil moisture or precipitation during the period, probably as a result of both the hysteretic effect of precipitation on transpiration, and changes in LAI throughout the growing season. Stand transpiration during the three growing seasons ranged from 75 to 106 mm, representing low to normal values for the semi-arid forest. The proportion of transpiration by oak trees in the stand was stable ranging from 60% to 66% and corresponded to their basal area proportion of approximately 59%. The results suggest that the natural forest consisting mainly of oak trees is in a formal stage of forest development that maintains a normal magnitude of annual water consumption.

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

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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.

Managing an oak decline crisis in Oakville, Ontario: lessons learned

Science.gov (United States)

Peter A. Williams; John W. McNeil; Kurt W. Gottschalk; Robert A. Haack

2013-01-01

The town of Oakville, Ontario, is located along the north shore of Lake Ontario between Toronto and Hamilton. In the fall of 2002, significant oak (Quercus spp.) mortality was observed at Oakville's Iroquois Shoreline Woods Park, an environmentally significant forest remnant noted for its oak-dominated forests. Investigations suggested that oak...

Facilitating Oak and Hickory Regeneration in Mature Central Hardwood Forests

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Eric J. Holzmueller

2014-12-01

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

Impacts of Potential Oak Forest Change on Breeding Birds in Northwestern Arkansas

Science.gov (United States)

Douglas A. James

2004-01-01

Birds found on existing census routes in the Ozark region of northwestern Arkansas were used to predict avifaunal changes that could occur in the area due to oak-hickory forest degradation caused by red oak borer beetle infestations. The two census routes used passed through high elevation forests where red oaks thrive the best. Analysis showed that 21 bird species...

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

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Imre Berki

2016-12-01

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

Mammals of the Oak forest

International Nuclear Information System (INIS)

Otalora Ardila, Aida

2003-01-01

The high rate of deforestation over the Andean forests has generated a large proportion of fragmented landscapes in the country. The distribution of oak groves in the country was determined based on ecosystem maps. Charala and Encino oak groves patches are the largest ones found at the east Andes and like others, due to the unfair use of these resources, have suffered a fragmentation process. Fifty-five species of mammals included in 10 orders and 14 families were found in these forests. Chiroptera and Rodentia were the most representative groups. Anthropic processes had produced a 68.1% loss of the habitat and constitute the main threat for these forests. The sizes of the patches were evaluated for three mammal species categories. The patches' area are not favorable for large-size species, intermediately to favorable to medium-size species and are favorable for small-size species. It is suggested that patches' area effect over mammal species could relate to the decrease of species richness and of each fragment area. There are good connections between patches (only five isolated), allowing the presence of a greater species diversity. There is also a bleak plateau zone between connected patches increasing their connectivity and offering different habitats and resources for some mammal species

Indiana's Forests 2008

Science.gov (United States)

Christopher W. Woodall; Mark N. Webb; Barry T. Wilson; Jeff Settle; Ron J. Piva; Charles H. Perry; Dacia M. Meneguzzo; Susan J. Crocker; Brett J. Butler; Mark Hansen; Mark Hatfield; Gary Brand; Charles. Barnett

2011-01-01

The second full annual inventory of Indiana's forests reports more than 4.75 million acres of forest land with an average volume of more than 2,000 cubic feet per acre. Forest land is dominated by the white oak/red oak/hickory forest type, which occupies nearly a third of the total forest land area. Seventy-six percent of forest land consists of sawtimber, 16...

Regeneration of native California oaks in the forest zone [Abstract

Science.gov (United States)

P.M. McDonald

1999-01-01

The two native California oaks in the forest zone of California are California black oak (Quercus kelloggii Newb.) and tanoak (Lithocarpus densiflorus [Hook. and Arn.] Rehd.). Both are ancient species with many adaptations to withstand California's Mediterranean climate, but some weaknesses as well. Both sprout vigorously...

Phytosociological studies of the forests with sessile oak and Norway spruce from South-Eastern Transylvania

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Adrian Indreica

2011-02-01

Full Text Available The forests with sessile oak (Quercus petraea and Norway spruce (Picea abies from south-eastern Transylvania represent a peculiar type of phytocenoses, rather unusual for the present-day vegetation of Romania’s territory. Aim of the study is to provide a detailed description of the vegetation and to identify the phytosociological and typological units to which it could belong. Beside this, stand structure and regeneration status of the main tree species are illustrated. The studied area is located around Carpathian intermountain depressions Braşov and Ciuc, where vegetation had a peculiar history and today sessile oak forests on high altitude exists, interfering with spruce forests. The hypothesis of the process naturalness is supported by vegetation history in the area, climate, stand structure and peculiarities of herb layer composition (the mixture of relic of both mountain-boreal origin and south-European origin, like Vaccinium vitis-idaea, Pyrola rotundifolia and respectively Potentilla micrantha, Lathyrus venetus respectively. Sintaxonomically, studied phytocenoses with sessile oak and spruce belong mainly to acidophilus oak forests (Luzulo luzuloidis-Quercetum petraeae, but some of them resemble oak-hornbeam forests (Carici pilosae-Carpinetum, indicating a more recent change in stand structure and suggesting that not the soil, but the climate is the driving force of succession. Regeneration of sessile oak is at least satisfactory, but the expansion of spruce in such stands could seriously restrict the survival of sessile oak. A new typological unit will be appropriate,for a better management of sessile oak forests with spruce admixture.

Phytosociological studies of the forests with sessile oak and Norway spruce from South-Eastern Transylvania

Directory of Open Access Journals (Sweden)

Adrian Indreica

2011-06-01

Full Text Available The forests with sessile oak (Quercus petraea and Norway spruce (Picea abies from south-eastern Transylvania represent a peculiar type of phytocenoses, rather unusual for the present-day vegetation of Romania’s territory. Aim of the study is to provide a detailed description of the vegetation and to identify the phytosociological and typological units to which it could belong. Beside this, stand structure and regeneration status of the main tree species are illustrated. The studied area is located around Carpathian intermountain depressions Brasov and Ciuc, where vegetation had a peculiar history and today sessile oak forests on high altitude exists, interfering with spruce forests. The hypothesis of the process naturalness is supported by vegetation history in the area, climate, stand structure and peculiarities of herb layer composition (the mixture of relic of both mountain-boreal origin and south-European origin, like Vaccinium vitis-idaea, Pyrola rotundifolia and respectively Potentilla micrantha, Lathyrus venetus respectively. Sintaxonomically, studied phytocenoses with sessile oak and spruce belong mainly to acidophilus oak forests (Luzulo luzuloidis-Quercetum petraeae, but some of them resemble oak-hornbeam forests (Carici pilosae-Carpinetum, indicating a more recent change in stand structure and suggesting that not the soil, but the climate is the driving force of succession. Regeneration of sessile oak is at least satisfactory, but the expansion of spruce in such stands could seriously restrict the survival of sessile oak. A new typological unit will be appropriate, for a better management of sessile oak forests with spruce admixture.

Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

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Wen J Wang

Full Text Available Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest vulnerability to oak decline by removing susceptible species and declining trees. However, the long-term, landscape-scale effects of these different harvest alternatives are not well studied because of the limited availability of experimental data. In this study, we applied a forest landscape model in combination with field studies to evaluate the effects of the three harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape. Results showed that the potential oak decline in high risk sites decreased strongly in the next five decades irrespective of harvest alternatives. This is because oak decline is a natural process and forest succession (e.g., high tree mortality resulting from intense competition would eventually lead to the decrease in oak decline in this area. However, forest harvesting did play a role in mitigating oak decline and the effectiveness varied among the three harvest alternatives. The group selection and clearcutting alternatives were most effective in mitigating oak decline in the short and medium terms, respectively. The long-term effects of the three harvest alternatives on mitigating oak decline became less discernible as the role of succession increased. The thinning alternative had the highest biomass retention over time, followed by the group selection and clearcutting alternatives. The group selection alternative that balanced treatment effects and retaining biomass was the most viable alternative for managing oak decline. Insights from this study may be useful in developing effective and informed forest harvesting plans for managing oak

Regime shifts and weakened environmental gradients in open oak and pine ecosystems.

Science.gov (United States)

Hanberry, Brice B; Dey, Dan C; He, Hong S

2012-01-01

Fire suppression allows tree species that are intolerant of fire stress to increase their distribution, potentially resulting in disruption of historical species-environmental relationships. To measure changes between historical General Land Office surveys (1815 to 1850) and current USDA Forest Inventory and Assessment surveys (2004 to 2008), we compared composition, distribution, and site factors of 21 tree species or species groups in the Missouri Ozarks. We used 24 environmental variables and random forests as a classification method to model distributions. Eastern redcedar, elms, maples, and other fire-sensitive species have increased in dominance in oak forests, with concurrent reductions by oak species; specific changes varied by ecological subsection. Ordinations displayed loss of separation between formerly distinctive oak and fire-sensitive tree species groups. Distribution maps showed decreased presence of disturbance-dependent oak and pine species and increased presence of fire-sensitive species that generally expanded from subsections protected from fire along rivers to upland areas, except for eastern redcedar, which expanded into these subsections. Large scale differences in spatial gradients between past and present communities paralleled reduced influence of local topographic gradients in the varied relief of the Missouri Ozarks, as fire-sensitive species have moved to higher, drier, and sunnier sites away from riverine corridors. Due to changes in land use, landscapes in the Missouri Ozarks, eastern United States, and world-wide are changing from open oak and pine-dominated ecosystems to novel oak-mixed species forests, although at fine scales, forests are becoming more diverse in tree species today. Fire suppression weakened the influence by environmental gradients over species dominance, allowing succession from disturbance-dependent oaks to an alternative state of fire-sensitive species. Current and future research and conservation that rely on

Social participation and oak forest conservation: Paipa and Duitama study case

International Nuclear Information System (INIS)

Escobar Torres, Vivian Constanza; Palacio Tamayo, Dolly Cristina

2010-01-01

Social dynamics within social participation is a crucial issue for the accomplishment of forest conservation. In order to contribute to this field, a study of 31 institutional and community organized actors' cooperative practices, within forest conservation processes in Paipa and Duitama, located at the oak forests conservation corridor Guantiva, La Rusia, Iguaque in Colombia, was made, applying Social Network Analysis (SNA). Particularly, this article inquiry is about models of participation of these actors within the period of 2004-2008, looking at their projects and actions as management practices of forest conservation. The research questions were how social participation is included and understood in the conservation of these oak forests, observing cooperative practices amongst this set of actors, at local level. The results are related with the structural patterns of co-participation established amongst these actors within each other's projects and actions and the impact of those in the aim of forest conservation at local level, regarding power relations and its impact on forest conservation.

The efforts for cork oak forest management and their effects on soil conservation

Energy Technology Data Exchange (ETDEWEB)

Laouina, A.; Aderghal, M.; Al Karkouri, J.; Antari, M.; Chaker, M.; Laghazi, Y.; Machmachi, I.; Machouri, N.; Nafaa, R.; Naimi, K.; Nouira, A.; Sfa, M.

2010-07-01

The Shoul oak grove is a forested ecosystem inherited from a Holocene phase of ecological optimum; its evolution, through the double geologic and human temporality, and in relation with several processes of degradation, led to the progressive loss of its environmental equilibrium and further to the reduction of its economic contributions. The fragility of these forests is the consequence of the convergence of two main factors, i) the intrinsic fragility of the forested environment based on an unstable balance between the tree, the leached soils and their moisture content ; ii) the anthropological action on the forest environment and its degradation with the change of its floristic composition. During the colonization the new context was at the origin of the new social and economic relation between the forest and the surrounding populations. The current use of this oak grove is in a classic scheme of the reports society / forest in Morocco. The population is especially of pastoral main activity in the bordering communes. But the oak groves of Mamora-Sehoul are integrated into the area of influence of several cities, what exposes the forest to the risks of uncontrolled urbanization. These oak groves are thus in the centre of interest of several stake holders with opposite behaviour and a new paradigm of relation rural/urban. Through a double approach, environmental and socio-economic, this paper will try to bring elements of answer by analyzing the interactions between a forest which reached an alarming threshold of degradation and a society affected by important changes in its modes of intervention and exploitation. (Author) 28 refs.

Forest structure of oak plantations after silvicultural treatment to enhance habitat for wildlife

Science.gov (United States)

Twedt, Daniel J.; Phillip, Cherrie-Lee P.; Guilfoyle, Michael P.; Wilson, R. Randy; Schweitzer, Callie Jo; Clatterbuck, Wayne K.; Oswalt, Christopher M.

2016-01-01

During the past 30 years, thousands of hectares of oak-dominated bottomland hardwood plantations have been planted on agricultural fields in the Mississippi Alluvial Valley. Many of these plantations now have closed canopies and sparse understories. Silvicultural treatments could create a more heterogeneous forest structure, with canopy gaps and increased understory vegetation for wildlife. Lack of volume sufficient for commercial harvest in hardwood plantations has impeded treatments, but demand for woody biomass for energy production may provide a viable means to introduce disturbance beneficial for wildlife. We assessed forest structure in response to prescribed pre-commercial perturbations in hardwood plantations resulting from silvicultural treatments: 1) row thinning by felling every fourth planted row; 2) multiple patch cuts with canopy gaps of gaps appear likely to be filled by regenerating saplings.

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

Science.gov (United States)

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

2010-01-01

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

Approaches to Scandinavian Crime Fiction

DEFF Research Database (Denmark)

Agger, Gunhild

2010-01-01

as the approach of genre typology and the concept of evil – seemingly disparate concepts and approaches, but all related to the complex processes in the borderlands between crime fiction and society. Using examples from Scandinavian crime fiction, I discuss whether the growing proximity to international genres......The working paper discusses some of the major approaches to Scandinavian crime fiction in the light of the dominant features of crime culture, e.g. the broad exposure of crime fiction via different platforms and media. In this connection, the concept of mediatization is considered as well......, ways of production and standards increasingly removes Scandinavian crime fiction from its original attractions or not....

Assessing management effects on Oak forests in Austria

Science.gov (United States)

Gautam, Sishir; Pietsch, Stephan A.; Hasenauer, Hubert

2010-05-01

Historic land use as well as silvicultural management practices have changed the structures and species composition of central European forests. Such changes have effects on the growth of forests and contribute to global warming. As insufficient information on historic forest management is available it is hard to explain the effect of management on forests growth and its possible consequences to the environment. In this situation, the BIOME-BGC model, which integrates the main physical, biological and physiological processes based on current understanding of ecophysiology is an option for assessing the management effects through tracking the cycling of energy, water, carbon and nutrients within a given ecosystems. Such models are increasingly employed to simulate current and future forest dynamics. This study first compares observed standing tree volume, carbon and nitrogen content in soil in the high forests and coppice with standards stands of Oak forests in Austria. Biome BGC is then used to assess the effects of management on forest growth and to explain the differences with measured parameters. Close positive correlations and unbiased results and statistically insignificant differences between predicted and observed volumes indicates the application of the model as a diagnostic tool to assess management effects in oak forests. The observed data in 2006 and 2009 was further compared with the results of respective model runs. Further analysis on simulated data shows that thinning leads to an increase in growth efficiency (GE), nitrogen use efficiency (NUE) and water use efficiency (WUE), and to a decrease in the radiation use efficiency (RUE) in both forests. Among all studied growth parameters, only the difference in the NUE was statistically significant. This indicates that the difference in the yield of forests is mainly governed by the NUE difference in stands due to thinning. The coppice with standards system produces an equal amount of net primary

The macrofungal diversity and community of Atlantic oak (Quercus petraea and Q. robur forests in Ireland

Directory of Open Access Journals (Sweden)

Harrington, Thomas J.

2012-06-01

Full Text Available The oak species Quercus petraea and Q. Robur are dominant canopy tree species of native deciduous forests in Ireland and coastal regions of Western Europe. These forests are typically plant species-rich, and can also have a rich fungal flora. This survey examined macrofungi found in five native oak sites across Ireland over three years. Overall, 94 macrofungal species belonging to 39 genera were discovered with Mycena, Lactarius, Russula and Cortinarius the most species-rich genera. The species accumulation curve did not show signs of levelling off, indicating that more sampling would reveal more new species. Species richness estimation using the Chao2 estimator indicated that up to 135 species may be present across all of our plots, with individual plots receiving estimates from 19 to 61 species per plot. Sampled-based rarefaction analysis showed no significant differences in macrofungal species richness between our plots. The five most common species were Laccaria amethystina, L. laccata, Stereum hirsutum, Armillaria mellea and Cortinarius flexipes. Comparisons of the results with results from oak forests in similar regions found that the communities in Great Britain were most similar to those found in Ireland. There were some key oak forest distinguishing fungal species from the family Boletaceae lacking from Irish oak forests. It is hypothesised that the historic deforestation of Ireland, caused a reduction of suitable habitats for Irish oak associated macrofungi, leading to the unspecific mycota found in the oak forests of this study. The threats to Atlantic oak forests in Ireland are briefly discussed.Las especies de Quercus petraea y Q. Robur se encuentran en bosques de Irlanda y regiones de influencia atlántica de Europa Occidental. Estos bosques, típicamente ricos en especies de plantas, presentan una abundante micobiota. Este estudio examina la diversidad de macromicetes en cinco bosques naturales de roble en Irlanda durante un

Sustaining oak forests in eastern North America: regeneration and recruitment, the pillars of sustainability

Science.gov (United States)

Daniel C. Dey

2014-01-01

Oak cover types comprise half of the forestlands in the eastern United States. There is a great desire to sustain these highly valued forests. Unfortunately, reports of the successional replacement of oak are all too common, as they are throughout the world. Sustaining the oak resource requires the ability to both regenerate and recruit oak into the overstory as...

Establishing Mixtures of Redcedar In Poor Oak-Hickory Forests

Science.gov (United States)

Leon S. Minckler

1966-01-01

Oak-history forests on the poorest sites in the Upper Mississippi Valley have both low productivity and little esthetic appeal. A mixture of the native evergreen redcedar would add bearty and increase wildlife values.

Regime shifts and weakened environmental gradients in open oak and pine ecosystems.

Directory of Open Access Journals (Sweden)

Brice B Hanberry

Full Text Available Fire suppression allows tree species that are intolerant of fire stress to increase their distribution, potentially resulting in disruption of historical species-environmental relationships. To measure changes between historical General Land Office surveys (1815 to 1850 and current USDA Forest Inventory and Assessment surveys (2004 to 2008, we compared composition, distribution, and site factors of 21 tree species or species groups in the Missouri Ozarks. We used 24 environmental variables and random forests as a classification method to model distributions. Eastern redcedar, elms, maples, and other fire-sensitive species have increased in dominance in oak forests, with concurrent reductions by oak species; specific changes varied by ecological subsection. Ordinations displayed loss of separation between formerly distinctive oak and fire-sensitive tree species groups. Distribution maps showed decreased presence of disturbance-dependent oak and pine species and increased presence of fire-sensitive species that generally expanded from subsections protected from fire along rivers to upland areas, except for eastern redcedar, which expanded into these subsections. Large scale differences in spatial gradients between past and present communities paralleled reduced influence of local topographic gradients in the varied relief of the Missouri Ozarks, as fire-sensitive species have moved to higher, drier, and sunnier sites away from riverine corridors. Due to changes in land use, landscapes in the Missouri Ozarks, eastern United States, and world-wide are changing from open oak and pine-dominated ecosystems to novel oak-mixed species forests, although at fine scales, forests are becoming more diverse in tree species today. Fire suppression weakened the influence by environmental gradients over species dominance, allowing succession from disturbance-dependent oaks to an alternative state of fire-sensitive species. Current and future research and

Change in oak abundance in the eastern United States from 1980 to 2008

Science.gov (United States)

Songlin Fei; Ningning Kong; Kim C. Steiner; W. Keith Moser; Eric B. Steiner

2011-01-01

Although oaks (Quercus spp.) have historically dominated much of the forest land in eastern North America, a great deal of fragmentary and sometimes anecdotal evidence suggests that they have been yielding dominance in recent decades to other, typically more shade-tolerant species. Using FIA data, our work formally quantifies the change in oak abundance in the eastern...

Monitoring oak-hickory forest change during an unprecedented red oak borer outbreak in the Ozark Mountains: 1990 to 2006

Science.gov (United States)

Jones, Joshua S.; Tullis, Jason A.; Haavik, Laurel J.; Guldin, James M.; Stephen, Fred M.

2014-01-01

Upland oak-hickory forests in Arkansas, Missouri, and Oklahoma experienced oak decline in the late 1990s and early 2000s during an unprecedented outbreak of a native beetle, the red oak borer (ROB), Enaphalodes rufulus (Haldeman). Although remote sensing supports frequent monitoring of continuously changing forests, comparable in situ observations are critical for developing an understanding of past and potential ROB damage in the Ozark Mountains. We categorized forest change using a normalized difference water index (NDWI) applied to multitemporal Landsat TM and ETM+ imagery (1990, 2001, and 2006). Levels of decline or growth were categorized using simple statistical thresholds of change in the NDWI over time. Corresponding decline and growth areas were then observed in situ where tree diameter, age, crown condition, and species composition were measured within variable radius plots. Using a machine learning decision tree classifier, remote sensing-derived decline and growth was characterized in terms of in situ observation. Plots with tree quadratic mean diameter at breast height ≥21.5 cm were categorized remotely as in severe decline. Landsat TM/ETM+-based NDWI derivatives reveal forest decline and regrowth in post-ROB outbreak surveys. Historical and future Landsat-based canopy change detection should be incorporated with existing landscape-based prediction of ROB hazard.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

The most significant fungi: Agents of wood decay in oak forests of Serbia

Directory of Open Access Journals (Sweden)

Milijašević Tanja

2007-01-01

Full Text Available The most widely distributed oak species in Serbia are Q. petrea (sessile oak, Q. cerris (Turkey oak and Q. frainetto (Hungarian oak and Quercus robur (common oak, and lignicolous fungi are the major agents of wood decay in natural and coppice oak forests. In this research, 33 species of fungi were identified. Eleven species were described, among which the most significant are: Armillaria mellea, Fomes fomentarius, Hypoxylon deustum Laetiporus sulphureus, Lenzites quercina and Phellinus robustus. This paper presents the morphological characteristics of the most significant identified fungi, their distribution, host plants and significance.

Long-term persistence and fire resilience of oak shrubfields in dry conifer forests of northern New Mexico

Science.gov (United States)

Guiterman, Christopher H.; Margolis, Ellis; Allen, Craig D.; Falk, Donald A.; Swetnam, Thomas W.

2017-01-01

Extensive high-severity fires are creating large shrubfields in many dry conifer forests of the interior western USA, raising concerns about forest-to-shrub conversion. This study evaluates the role of disturbance in shrubfield formation, maintenance and succession in the Jemez Mountains, New Mexico. We compared the environmental conditions of extant Gambel oak (Quercus gambelii) shrubfields with adjoining dry conifer forests and used dendroecological methods to determine the multi-century fire history and successional dynamics of five of the largest shrubfields (76–340 ha). Across the study area, 349 shrubfields (5–368 ha) occur in similar topographic and climate settings as dry conifer forests. This suggests disturbance, rather than other biophysical factors, may explain their origins and persistence. Gambel oak ages and tree-ring fire scars in our sampled shrubfields indicate they historically (1664–1899) burned concurrently with adjoining conifer forests and have persisted for over 115 years in the absence of fire. Aerial imagery from 1935 confirmed almost no change in sampled shrubfield patch sizes or boundaries over the twentieth century. The largest shrubfield we identified is less than 4% the size of the largest conifer-depleted and substantially shrub-dominated area recently formed in the Jemez following extensive high-severity wildfires, indicating considerable departure from historical patterns and processes. Projected hotter droughts and increasingly large high-severity fires could trigger more forest-to-shrub transitions and maintain existing shrubfields, inhibiting conifer forest recovery. Restoration of surface fire regimes and associated historical forest structures likely could reduce the rate and patch size of dry conifer forests being converted to shrubfields.

Changes in understory species occurrence of a secondary broadleaved forest after mass mortality of oak trees under deer foraging pressure

Directory of Open Access Journals (Sweden)

Hiroki Itô

2016-12-01

Full Text Available The epidemic of mass mortality of oak trees by Japanese oak wilt has affected secondary deciduous broadleaved forests that have been used as coppices in Japan. The dieback of oak trees formed gaps in the crown that would be expected to enhance the regeneration of shade-intolerant pioneer species. However, foraging by sika deer Cervus nippon has also affected forest vegetation, and the compound effects of both on forest regeneration should be considered when they simultaneously occur. A field study was conducted in Kyôto City, Japan to investigate how these compound effects affected the vegetation of the understory layer of these forests. The presence/absence of seedlings and saplings was observed for 200 quadrats sized 5 m ×5 m for each species in 1992, before the mass mortality and deer encroachment, and in 2014 after these effects. A hierarchical Bayesian model was constructed to explain the occurrence, survival, and colonization of each species with their responses to the gaps that were created, expanded, or affected by the mass mortality of Quercus serrata trees. The species that occurred most frequently in 1992, Eurya japonica, Quercus glauca, and Cleyera japonica, also had the highest survival probabilities. Deer-unpalatable species such as Symplocos prunifolia and Triadica sebifera had higher colonization rates in the gaps, while the deer-palatable species Aucuba japonica had the smallest survival probability. The gaps thus promoted the colonization of deer-unpalatable plant species such as Symplocos prunifolia and Triadica sebifera. In the future, such deer-unpalatable species may dominate gaps that were created, expanded, or affected by the mass mortality of oak trees.

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

Science.gov (United States)

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

2015-01-01

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

Illinois' Forests 2005

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Susan J. Crocker; Gary J. Brand; Brett J. Butler; David E. Haugen; Dick C. Little; Dacia M. Meneguzzo; Charles H. Perry; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall

2009-01-01

The first full, annualized inventory of Illinois' forests reports more than 4.5 million acres of forest land with an average of 459 trees per acre. Forest land is dominated by oak/hickory forest types, which occupy 65 percent of total forest land area. Seventy-two percent of forest land consists of sawtimber, 20 percent contains poletimber, and 8 percent contains...

Effects of dust on forest tree health in Zagros oak forests.

Science.gov (United States)

Moradi, A; Taheri Abkenar, K; Afshar Mohammadian, M; Shabanian, N

2017-10-10

Dust is one of the most devastating factors for the environment threatening all animal and plant species. In many regions, the ecological and economic impact of microdust on scarce species is critical. In the western region of Iran, the Zagros forests have been exposed to dust storms for many years. In this study, the effect of dust on oak trees, the most important trees of Zagros forests, is investigated. For this purpose, 3-year-old seedlings of three species of oak trees under natural conditions were exposed to dust during spring and summer months. Seedlings were divided into two groups; one group was assigned as dust treatment and the other as control that the control group washed regularly to remove dust. Anatomical characteristics of leaves and dust deposits on leaves during the study period were examined by scanning electron microscope (SEM). The rate of photosynthesis and gas exchange in control and treated plants was examined by IRGA, LCI. SEM images showed that stomata structure, trichome density, and epicuticular waxes of leaves are different in all three species. This difference in micromorphology of species influences the effects of dust deposited on the leaves. A comparison of leaf species images in control and dust treatment showed that in dust treatment the percentage of stomata blocked by dust in three species (per unit area) of Quercus infectoria, Q. libni, and Q. brantii were 61/6, 48/4, and 38/1%, respectively. The results of leaf gas exchange investigation indicated that stomatal occlusion by dust had a negative impact on the examined parameters of three oak species (P ≤ 0.01). Thus, gas exchange and photosynthetic rates of the treated species were significantly reduced. The results of both parts of the study showed the vulnerability of the three species to dust as Q. infectoria > Q. libni > Q. brantii. Therefore, based on these findings, dust can disrupt the physiological activities of the studied species and the continuation of the

Illinois' Forests 2010

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Susan J. Crocker; Mark D. Nelson; Charles J. Barnett; Brett J. Butler; Grant M. Domke; Mark H. Hansen; Mark A. Hatfield; Tonya W. Lister; Dacia M. Meneguzzo; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall

2013-01-01

The second full annual inventory of Illinois' forests, completed in 2010, reports more than 4.8 million acres of forest land and 97 tree species. Forest land is dominated by oak/hickory and elm/ash/cottonwood forest-type groups, which occupy 93 percent of total forest land area. The volume of growing stock on timberland totals 7.2 billion cubic feet. The average...

Nebraska's Forests 2010

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Dacia M Meneguzzo; Susan J. Crocker; Mark D. Nelson; Charles J. Barnett; Brett J. Butler; Grant M. Domke; Mark H. Hansen; Mark A. Hatfield; Greg C. Liknes; Andrew J. Lister; Tonya W. Lister; Ronald J. Piva; Barry T. (Ty) Wilson; Christopher W. Woodall

2012-01-01

The second full annual inventory of Nebraska's forests reports more than 1.5 million acres of forest land and 39 tree species. Forest land is dominated by the elm/ash/cottonwood and oak/hickory forest types, which occupy nearly half of the total forest land area. The volume of growing stock on timberland currently totals 1.1 billion cubic feet. The average annual...

Use of forest species associated to oak forests (Quercus humboldtii Bonpl.) for energetic purposes, in three villages of the Encino municipality in Santander

International Nuclear Information System (INIS)

Diaz Silva, Monica Rocio de las Mercedes

2010-01-01

We surveyed the firewood consumption for energetic purposes from the oak forest of the Patios Altos and Canada villages in Encino-Santander. Tools used to collect data were: structured surveys, open interviews and participant observation to those families dependent upon forest resources. Twenty-one species for domestic use were recorded, from which seven were related to the oak for est. The most preferred and used tree species was the Oak (Quercus humboldtii Bonpl) followed by the Laurel (Morella pubescens (Humb. and Bonpl. ex Willd.) Wilbur). Results show that 98% of the population uses only firewood and firewood alternated with gas, which suggests the importance of firewood to the community. Firewood consumption per person is 3.6 + - 1.35 kg per day, while annual consumption of the whole group (54 families) is the 354.78 kg per year. This usage corresponds to native tree species (78.2%), native shrubs 12.4%) and exotics (9.3%). Firewood usage represents savings to local inhabitants, corresponding to 33% of their monthly earnings, approximate Oak forest, Colombia, wood demand, native forest species, firewood, domestic use of wood.

An Old-Growth Definition for Dry and Dry-Mesic Oak-Pine Forests.

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David L. White; F. Thomas. Lloyd

1998-01-01

Dry and dry-mesic oak-pine forests are widely distributed from New Jersey to Texas, but representative old-growth stands are rare. Historical accounts of composition, along with information from existing old-growth stands, were used to characterize this type. Shortleaf pine and white oak were the most widely distributed trees across all old-growth stands. Shortleaf was...

Tree and forest water use under elevated CO2 and temperature in Scandinavian boreal forest

Science.gov (United States)

Berg Hasper, Thomas; Wallin, Göran; Lamba, Shubhangi; Sigurdsson, Bjarni D.; Laudon, Hjalmar; Medhurst, Jane L.; Räntfors, Mats; Linder, Sune; Uddling, Johan

2014-05-01

predictions of boreal atmosphere-biosphere interactions, indicating that tree responses to precipitation and temperature are more important than responses to elevated [CO2] in determining the future forest water-use and hydrology of Scandinavian boreal ecosystems.

The symbiotic relationship between dominant canopy trees and soil microbes affects the nitrogen source utilization of co-existing understory trees

Science.gov (United States)

Iwaoka, C.; Hyodo, F.; Taniguchi, T.; Shi, W.; Du, S.; Yamanaka, N.; Tateno, R.

2017-12-01

The symbiotic relationship between dominant canopy trees and soil microbes such as mycorrhiza or nitrogen (N) fixer are important determinants of soil N dynamics of a forest. However, it is not known how and to what extent the symbiotic relationship of dominant canopy trees with soil microbes affect the N source of co-existing trees in forest. We measured the δ15N of surface soils (0-10 cm), leaves, and roots of the dominant canopy trees and common understory trees in an arbuscular mycorrhizal N-fixing black locust (Robinia pseudoacacia) plantation and an ectomycorrhizal oak (Quercus liaotungensis) natural forest in a China dryland. We also analyzed the soil dissolved N content in soil extracts and absorbed by ion exchange resin, and soil ammonia-oxidizer abundance using real-time PCR. The δ15N of soil and leaves were higher in the black locust forest than in the oak forest, although the δ15N of fine roots was similar in the two forests, in co-existing understory trees as well as dominant canopy trees. Accordingly, the δ15N of leaves was similar to or higher than that of fine roots in the black locust forest, whereas it was consistently lower than that of fine roots in the oak forest. In the black locust forest, the soil dissolved organic N and ammonium N contents were less abundant but the nitrate N contents in soils and absorbed by the ion exchange resin and ammonia-oxidizer abundance were greater, due to N fixation or less uptake of organic N from arbuscular mycorrhiza. In contrast, the soil dissolved organic N and ammonium N contents were more abundant in the oak forest, whereas the N content featured very low nitrate, due to ectomycorrhizal ability to access organic N. These results suggest that the main N source is nitrate N in the black locust forest, but dissolved organic N or ammonium N in the oak forest. N fixation or high N loss due to high N availability would cause high δ15N in soil and leaves in black locust forest. On the other hand, low soil N

Impact of Market-Based Disturbance on the Composition of West Virginia's Forest Resource

Science.gov (United States)

William G. Luppold; John E. Baumgras; John E. Baumgras

2000-01-01

The eastern hardwood resource has been shaped by a combination of human and natural disturbances. This impact on the forest resources of West Virginia has been especially dramatic. This resource has changed from a virgin forest dominated white oak, chestnut, spruce, white pine, and hemlock in the late 19th century, to one dominated by red oak in the 1950's, to...

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

Science.gov (United States)

Tom Coleman; Steven Seybold

2016-01-01

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

West Virginia Forests 2013

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Randall S. Morin; Gregory W. Cook; Charles J. Barnett; Brett J. Butler; Susan J. Crocker; Mark A. Hatfield; Cassandra M. Kurtz; Tonya W. Lister; William G. Luppold; William H. McWilliams; Patrick D. Miles; Mark D. Nelson; Charles H. (Hobie) Perry; Ronald J. Piva; James E. Smith; Jim Westfall; Richard H. Widmann; Christopher W. Woodall

2016-01-01

The annual inventory of West Virginia's forests, completed in 2013, covers nearly 12.2 million acres of forest land with an average volume of more than 2,300 cubic feet per acre. This report is based data collected from 2,808 plots located across the State. Forest land is dominated by the oak/hickory forest-type group, which occupies 74 percent of total forest...

New Jersey's forests, 2008

Science.gov (United States)

Susan J. Crocker; Mark D. Nelson; Charles J. Barnett; Gary J. Brand; Brett J. Butler; Grant M. Domke; Mark H. Hansen; Mark A. Hatfield; Tonya W. Lister; Dacia M. Meneguzzo; Charles H. Perry; Ronald J. Piva; Barry T. Wilson; Christopher W. Woodall; Bill. Zipse

2011-01-01

The first full annual inventory of New Jersey's forests reports more than 2.0 million acres of forest land and 83 tree species. Forest land is dominated by oak-hickory forest types in the north and pitch pine forest types in the south. The volume of growing stock on timberland has been rising since 1956 and currently totals 3.4 billion cubic feet. The average...

Pennsylvania forests 2014

Science.gov (United States)

Thomas A. Albright; William H. McWilliams; Richard H. Widmann; Brett J. Butler; Susan J. Crocker; Cassandra M. Kurtz; Shawn Lehman; Tonya W. Lister; Patrick D. Miles; Randall S. Morin; Rachel Riemann; James E. Smith

2017-01-01

This report summarizes the third cycle of annualized inventory of Pennsylvania with field data collected from 2009 through 2014. Pennsylvania has 16.9 million acres of forest land dominated by sawtimber stands of oak/hickory and maple/beech/birch forest-type groups. Volumes continue to increase as the forests age with an average of 2,244 cubic feet per acre on...

Kentucky's forests, 2004

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Jeffery A. Turner; Christopher M. Oswalt; James L. Chamberlain; Roger C. Conner; Tony G. Johnson; Sonja N. Oswalt; KaDonna C. Randolph

2008-01-01

Forest land area in the Commonwealth of Kentucky amounted to 11.97 million acres, including 11.6 million acres of timberland. Over 110 different species, mostly hardwoods, account for an estimated 21.2 billion cubic feet of all live tree volume. Hardwood forest types occupy 85 percent of Kentucky’s timberland, and oak-hickory is the dominant forest-type group...

New Jersey Forests 2013

Science.gov (United States)

Susan J. Crocker; Charles J. Barnett; Brett J. Butler; Mark A. Hatfield; Cassandra M. Kurtz; Tonya W. Lister; Dacia M. Meneguzzo; Patrick D. Miles; Randall S. Morin; Mark D. Nelson; Ronald J. Piva; Rachel Riemann; James E. Smith; Christopher W. Woodall; William. Zipse

2017-01-01

The second full annual inventory of New Jersey’s forests reports more than 2.0 million acres of forest land and 77 tree species. Forest land is dominated by oak/hickory forest types in the north and pitch pine forest types in the south. The volume of growing stock on timberland has been rising since 1956 and currently totals 3.3 billion cubic feet. Average annual net...

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

Science.gov (United States)

Jennifer Juzwik; Jane Cummings-Carlson; Kyoko Scanlon

2010-01-01

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

Field test of foliar-spray herbicides to control mountain laurel in mature mixed-oak forests in western Maryland

Science.gov (United States)

Gary W. Miller; Patrick H. Brose; Jeffrey D. Kochenderfer; James N. Kochenderfer; Kurt W. Gottschalk; John R. Denning

2016-01-01

Successful oak (Quercus spp.) regeneration requires the presence of competitive sources of oak reproduction before parent oaks are harvested. Mountain laurel (Kalmia latifolia) in the understory of many Appalachian forests prevents new oak seedlings from receiving adequate sunlight to survive and grow into competitive size classes. This study examined the efficacy of...

[Impact of cork oak management on the ectomycorrhizal fungal diversity associated with Quercus suber in the Mâamora forest (Morocco)].

Science.gov (United States)

Maghnia, Fatima Z; Sanguin, Hervé; Abbas, Younes; Verdinelli, Marcello; Kerdouh, Benaissa; El Ghachtouli, Naima; Lancellotti, Enrico; Bakkali Yakhlef, Salah Eddine; Duponnois, Robin

2017-05-01

The cork oak forest is an ecosystem playing a major role in Moroccan socio-economy and biodiversity conservation. However, this ecosystem is negatively impacted by extensive human- and climate-driven pressures, causing a strong decrease in its distribution and a worsening of the desertification processes. This study aims at characterising the impact of cork oak forest management on a major actor of its functioning, the ectomycorrhizal (EcM) fungal community associated with Quercus suber, and the determination of EcM bio-indicators. The EcM fungal community has been monitored during spring and winter seasons in two sites of the Moroccan Mâamora forest, corresponding to a forest site either impacted by human activities or protected. A significant impact of cork oak forest management on the EcM fungal community has been revealed, with major differences during the summer season. The results confirmed the potential ecological significance of several EcM fungi (e.g., Cenococcum) in the sustainability of the cork oak forest functioning, but also the significant association of certain EcM fungi (Pachyphloeus, Russula, Tomentella) with a perturbation or a season, and consequently to the cork oak forest status or to climatic conditions, respectively. The development of study at the Mediterranean scale may improve the robustness of ecological models to predict the impact of global changes on this emblematic ecosystem of Mediterranean basin. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Coarse woody debris facilitates oak recruitment in Bialowieza Primeval Forest, Poland

NARCIS (Netherlands)

Smit, Christian; Kuijper, Dries P. J.; Prentice, David; Wassen, Martin J.; Cromsigt, Joris P. G. M.

2012-01-01

While oaks contribute to the ecology and economy of temperate lowland forests, recruitment into larger size classes is generally scarce. Ungulate herbivory is a limiting factor for tree recruitment, thus natural structures protecting against ungulates may be important for recruitment success. We

Changes in the species composition and structure of the herb layer of a thermophilous oak forest subject to clear cutting

Directory of Open Access Journals (Sweden)

Hieronim Andrzejewski

2014-01-01

Full Text Available Changes in the herb layer of a thermophilous oak forest (Potentillo albae-Quercetum, subject to clear cutting and artificial reforestation with Scotch pine monoculture, were analysed by a comparative method. It was found that cutting of a tree stand and underbrush did not destroy phytocoenose totally. Floristically-rich clearance communities resembled in their composition and structure the ground layer of an natural form of an oak forest. The regress of the herb layer took place several years later in a young pine stand. Then, a compact tree canopy highly restricted light inflow to the bottom of a forest. Later, thinning of a forest stand enabled the herb layer to regenerate. Nevertheless, even 60 years after clear cutting it significantly differed from the herb layer of a natural oak forest.

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

Science.gov (United States)

Paul G. Rodewald; Kimberly G. Smith

1998-01-01

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

Long-term effects of single prescribed fires on hardwood regeneration in oak shelterwood stands

Science.gov (United States)

Patrick H. Brose

2010-01-01

One of the arguments against using prescribed fire to regenerate oak (Quercus spp.) forests is that the improvement in species composition of the hardwood regeneration pool is temporary and multiple burns are necessary to achieve and maintain oak dominance. To explore this concern, I re-inventoried a prescribed fire study conducted in the mid-1990s...

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...

Contrasting responses to drought of forest floor CO2 efflux in a loblolly pine plantation and a nearby Oak-Hickory forest

Science.gov (United States)

S. Palmroth; Chris A. Maier; Heather R. McCarthy; A. C. Oishi; H. S. Kim; Kurt H. Johnsen; Gabrial G. Katul; Ram Oren

2005-01-01

Forest floor C02 efflux (Fff) depends on vegetation type, climate, and soil physical properties. We assessed the effects of biological factors on Fff by comparing a maturing pine plantation (PP) and a nearby mature Oak-Hickory-type hardwood forest (HW). Fff was measured...

The tree-species-specific effect of forest bathing on perceived anxiety alleviation of young-adults in urban forests

Directory of Open Access Journals (Sweden)

Haoming Guan

2017-12-01

Full Text Available Forest bathing, i.e. spending time in a forest to walk, view and breathe in a forest, can alleviate the mental depression of visitors, but the tree-species-specific effect of this function by the urban forest is unknown. In this study, sixty-nine university students (aged 19-22, male ratio: 38% were recruited as participants to visit urban forests dominated by birch (Betula platyphylla Suk., maple (Acer triflorum Komarov and oak (Quercus mongolica Fisch. ex Ledeb trees in a park at the center of Changchun City, Northeast China. In the maple forest only the anxiety from study interest was decreased, while the anxiety from employment pressure was alleviated to the most extent in the birch forest. Participants perceived more anxiety from lesson declined in the oak forest than in the birch forest. Body parameters of weight and age were correlated with the anti-anxiety scores. In the oak forest, female participants can perceive more anxiety alleviation than male participants. For university students, forest bathing in our study can promote their study interest. Forest bathing can be more effective to alleviate the anxiety of young adults with greater weight. The birch forest was recommended to be visited by students to alleviate the pressure of employment worry, and the oak forest was recommended to be visited by girls.

Effect of long-term understory prescribed burning on standing and down dead woody material in dry upland oak forests

Science.gov (United States)

Polo, John A.; Hallgren, S.W.; Leslie,, David M.

2013-01-01

Dead woody material, long ignored or viewed as a nuisance for forest management, has gained appreciation for its many roles in the forest including wildlife habitat, nutrient storage and cycling, energy for trophic webs, protection of soil, fuel for fire and carbon storage. The growing interest in managing dead woody material has created strong demand for greater understanding of factors controlling amounts and turnover. Prescribed burning, an important management tool, may have strong effects of dead woody material given fire’s capacity to create and consume dead woody material. We determined effects of long-term understory prescribed burning on standing and down woody material in upland oak forests in south-central North America. We hypothesized that as frequency of fire increased in these stands the amount of deadwood would decrease and the fine woody material would decrease more rapidly than coarse woody material. The study was conducted in forests dominated by post oak (Quercus stellata) and blackjack oak (Quercus marilandica) in wildlife management areas where understory prescribed burning had been practiced for over 20 years and the range of burn frequencies was 0 (unburned) fires per decade (FPD) to 4.6 FPD. The amount of deadwood was low compared with more productive forests in southeastern North America. The biomass (24.7 Mg ha-1) and carbon stocks (11.7 Mg ha-1) were distributed among standing dead (22%), coarse woody debris (CWD, dia. > 7.5 cm., 12%), fine woody debris (FWD, dia. prescribed burning influenced the amount and size distribution of standing and down dead woody material. There were two explanations for the lack of a detectable effect. First, a high incidence of severe weather including ice storms and strong winds that produce large amounts of deadwood intermittently in an irregular pattern across the landscape may preclude detecting a strong effect of understory prescribed burning. Second, fire suppression during the first one-half of the

The dynamic response of housing values to a forest invasive disease: evidence from a sudden oak death infestation

Science.gov (United States)

Kent Kovacs; Thomas P Holmes; Jeffrey E Englin; Janice Alexander

2011-01-01

“Sudden Oak Death” (Phytophthora ramorum) is a non-indigenous forest pathogen which causes substantial mortality of coast live oak (Quercus agrifolia) and several other oak tree species on the Pacific Coast of the United States. We estimated the time path of residential property values subject to oak mortality using a dataset that spans more than two decades—including...

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

Science.gov (United States)

Scott R. Abella; Peter Z. Fulé

2008-01-01

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

Habitat use by bats in two Indiana forests prior to silvicultural treatments for oak regeneration

Science.gov (United States)

Jeremy J. Sheets; Joseph E. Duchamp; Megan K. Caylor; Laura D' Acunto; John O. Whitaker; Virgil Jr. Brack; Dale W. Sparks

2013-01-01

As part of a study examining the effects of silvicultural treatments for oak regeneration on habitat use by bats, we surveyed forest stands prior to the implementation of treatments in two state forests in Indiana. Interior forest sites corresponding to areas designated for silvicultural treatments were surveyed for 2 nights each during the summers of 2007 and 2008....

How Biotic Differentiation of Human Impacted Nutrient Poor Deciduous Forests Can Affect the Preservation Status of Mountain Forest Vegetation

Directory of Open Access Journals (Sweden)

Tomasz Durak

2016-10-01

Full Text Available A significant loss of biodiversity resulting from human activity has caused biotic homogenisation to become the dominant process shaping forest communities. In this paper, we present a rare case of biotic differentiation in European temperate deciduous forest herb layer vegetation. The process is occurring in nutrient poor oak-hornbeam forests in mountain areas (Polish Eastern Carpathians, Central Europe where non-timber use was converted into conventional forest management practice. This change contributed to increases in the nitrogen content and pH reaction of the soil that, contrary to predominant beliefs on the negative impact of habitat eutrophication on diversity, did not result in a decrease in the latter. We discuss possible reasons for this phenomenon that indicate the important role of tree stand composition (an increasing admixture of beech worsening the trophic properties of the soil. The second issue considered involves the effect of the changes in herb species composition of oak-hornbeam forest on its distinctiveness from the beech forest predominating in the Polish Eastern Carpathians. Unfortunately, despite the increase in the species compositional dissimilarity of oak-hornbeam forest, a reduction in their distinctiveness in relation to the herb species composition of beech forest was found. Such a phenomenon is an effect of the major fragmentation of oak-hornbeam forests, a spread of beech forest-type species, and forest management that gives preference to beech trees. Consequently, it can be expected that changes occurring in oak-hornbeam forest vegetation will contribute to a decrease in the forest vegetation variability at the regional scale.

A multi-century analysis of disturbance dynamics in pine-oak forests of the Missouri Ozark Highlands

Science.gov (United States)

Chad King; Rose-Marie. Muzika

2013-01-01

Using dendrochronology and growth release approaches, we analyzed the disturbance history of shortleaf pine (Pinus echinata Mich.) white oak (Quercus alba L.) forests in the Missouri Ozark Highlands. The objectives of this study were to (1) identify growth release events using living and remnant shortleaf pine and white oak, (2)...

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.

Fire behavioral changes as a result of sudden oak death in coastal California forests

Science.gov (United States)

Y. Vlachovic; C. Lee; H. Scanlon; J.M. Varner; R. Glebocki; B.D. Graham; D.M. Rizzo

2013-01-01

Field observations and anecdotal evidence suggest that sudden oak death (SOD), a disease caused by the pathogen Phytophthora ramorum, may alter fuel loading in affected forests. Though it is reasonable to assume that a disease resulting in leaf blight, dead branches, and tree mortality would increase forest fuels, little work has been done to...

Pedunculate oak forests (Quercus robur L. survey in the Ticino Regional Park (Italy by remote sensing

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Rossini M

2007-01-01

Full Text Available Pedunculate oak forests (Quercus robur L. in the Ticino Regional Park (Italy show sensible damage conditions due to different environmental stresses: insect attacks, summer drought and air pollution. Knowing whether oaks are healthy or stressed can provide useful information in order to conserve the forest ecosystems and avoid the lost of valuable natural resources. Environmental stresses can affect tree biochemical and structural variables, such as the concentration, composition and efficiency in light harvesting of foliar pigments, and the Leaf Area Index (LAI. Interest in the use of these variables for forest condition assessment has recently increased because they can be indirectly estimated from remote observations at leaf and canopy level. In particular, in this research we found that total chlorophyll (Chl concentration, a biochemical variable related to crown discoloration rate, was the most suitable variable for the detection of pedunculate oak decline in the Ticino Park. A regression analysis between Chl concentration and optical indices computed from hyperspectral MIVIS data was performed in order to estimate Chl concentration from remote observations. The good correlation between field measurements of Chl concentration and MIVIS optical indices allowed the development of a model to map Chl concentration across the Ticino Park forested area. Promising results demonstrated that remotely sensed data can provide an accurate estimation of Chl concentration and indicated the potential of this technique for forest condition monitoring.

Estimate of biomass and carbon pools in disturbed and undisturbed oak forests in Tunisia

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Zribi, L.; Chaar, H.; Khaldi, A.; Henchi, B.; Mouillot, F.; Gharbi, F.

2016-07-01

Aim of the study. To estimate biomass and carbon accumulation in a young and disturbed forest (regenerated after a tornado) and an aged cork oak forest (undisturbed forest) as well as its distribution among the different pools (tree, litter and soil). Area of study. The north west of Tunisia. Material and methods. Carbon stocks were evaluated in the above and belowground cork oak trees, the litter and the 150 cm of the soil. Tree biomass was estimated in both young and aged forests using allometric biomass equations developed for wood stem, cork stem, wood branch, cork branch, leaves, roots and total tree biomass based on combinations of diameter at breast height, total height and crown length as independent variables. Main results. Total tree biomass in forests was 240.58 Mg ha-1 in the young forest and 411.30 Mg ha-1 in the aged forest with a low root/shoot ratio (0.41 for young forest and 0.31 for aged forest). Total stored carbon was 419.46 Mg C ha-1 in the young forest and 658.09 Mg C ha-1 in the aged forest. Carbon stock (Mg C ha-1) was estimated to be113.61(27.08%) and 194.08 (29.49%) in trees, 3.55 (0.85%) and 5.73 (0.87%) in litter and 302.30 (72.07%) and 458.27 (69.64%) in soil in the young and aged forests, respectively. Research highlights. Aged undisturbed forest had the largest tree biomass but a lower potential for accumulation of carbon in the future; in contrast, young disturbed forest had both higher growth and carbon storage potential. (Author)

Decomposition and N cycling changes in redwood forests caused by sudden oak death

Science.gov (United States)

Richard C. Cobb; David M. Rizzo

2012-01-01

Phytophthora ramorum is an emergent pathogen in redwood forests which causes the disease sudden oak death. Although the disease does not kill coast redwood (Sequoia sempervirens), extensive and rapid mortality of tanoak (Notholithocarpus densiflorus) has removed this...

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

Patterns of tree species diversity and composition in old-field successional forests in central Illinois

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Scott M. Bretthauer; George Z. Gertner; Gary L. Rolfe; Jeffery O. Dawson

2003-01-01

Tree species diversity increases and dominance decreases with proximity to forest border in two 60-year-old successional forest stands developed on abandoned agricultural land in Piatt County, Illinois. A regression equation allowed us to quantify an increase in diversity with closeness to forest border for one of the forest stands. Shingle oak is the most dominant...

Soil moisture in sessile oak forest gaps

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Zagyvainé Kiss, Katalin Anita; Vastag, Viktor; Gribovszki, Zoltán; Kalicz, Péter

2015-04-01

By social demands are being promoted the aspects of the natural forest management. In forestry the concept of continuous forest has been an accepted principle also in Hungary since the last decades. The first step from even-aged stand to continuous forest can be the forest regeneration based on gap cutting, so small openings are formed in a forest due to forestry interventions. This new stand structure modifies the hydrological conditions for the regrowth. Without canopy and due to the decreasing amounts of forest litter the interception is less significant so higher amount of precipitation reaching the soil. This research focuses on soil moisture patterns caused by gaps. The spatio-temporal variability of soil water content is measured in gaps and in surrounding sessile oak (Quercus petraea) forest stand. Soil moisture was determined with manual soil moisture meter which use Time-Domain Reflectometry (TDR) technology. The three different sizes gaps (G1: 10m, G2: 20m, G3: 30m) was opened next to Sopron on the Dalos Hill in Hungary. First, it was determined that there is difference in soil moisture between forest stand and gaps. Second, it was defined that how the gap size influences the soil moisture content. To explore the short term variability of soil moisture, two 24-hour (in growing season) and a 48-hour (in dormant season) field campaign were also performed in case of the medium-sized G2 gap along two/four transects. Subdaily changes of soil moisture were performed. The measured soil moisture pattern was compared with the radiation pattern. It was found that the non-illuminated areas were wetter and in the dormant season the subdaily changes cease. According to our measurements, in the gap there is more available water than under the forest stand due to the less evaporation and interception loss. Acknowledgements: The research was supported by TÁMOP-4.2.2.A-11/1/KONV-2012-0004 and AGRARKLIMA.2 VKSZ_12-1-2013-0034.

The role of selected soil fauna as predators of Apethymus abdominalis Lep. (Hymenoptera: Tenthredinidae) in oak forests in the District Caiuti, Romania

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C. Ciornei; N. Popa; L. Ciuca; C. Rang

2003-01-01

The present study was initiated in 2001 in the oak forests from Trotus valley (Forest District Caiucti - Bacau, Romania) which were heavily infested by oak sawflies Apethymus abdominalis Lep. (Hymenoptera: Tenthredinidae), in order to understand better the role of soil-inhabitating predators in population regulation of this pest.

Evaluation of fire severity via analysis of photosynthetic pigments: Oak, eucalyptus and cork oak leaves in a Mediterranean forest.

Science.gov (United States)

Soler, M; Úbeda, X

2018-01-15

Few studies to date have examined the effect of the high temperatures attained during wildfire events on the pigments present in forest foliage. Here, we seek to analyse the main photosynthetic pigments in the leaves of the oak, cork oak and eucalyptus following a wildfire. We also subject leaves of these last two species to a range of contact temperatures (100-500 °C) in the laboratory using a muffle furnace. The samples were left in the muffle for two hours at 100, 150, 200, 250, 300, 350, 400 and 500 °C, in line with other soil study models (Úbeda et al., 2009; Düdaite et al., 2013). At temperatures above 250 °C, chromatography fails to detect any pigments. A minimal increase in temperature degrades chlorophyll, the process being more rapid in eucalyptus than in cork oak, while it increases pheophytin concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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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....

Comparison of growth response to thinning in oak forests managed as coppice with standards and high forest

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Gautam, S.; Hasenauer, H.; Pietsch, S. A.

2009-04-01

The BIOME-BGC model integrates the main physical, biological and physiological processes based on current understanding of ecophysiology to assess forest ecosystem dynamics. This study evaluates the application of the model to assess the thinning effects on coppiced oak forests in Austria. We analyze the growth response, i.e. growth efficiency (GE), nitrogen use efficiency (NUE), water use efficiency (WUE) and radiation use efficiency (RUE) of oak forests to thinning. The results of coppice with standards and high forests simulations are analysed for differences in simulated growth response after thinning. The forest field data of the year 2006 and the respective model runs are used to evaluate model application. Strong positive relationship (r2 = 0.90) with unbiased results and statistically insignificant differences between predicted and observed volume allows the use of the model as a diagnostic tool to assess management effects. Results indicate that the coppice with standards exhibits a significantly higher yield by 2.97% (i.e. 10 cubic meters per hectare in one rotation), a higher harvest (49.9%) but a lower growing stock (19.69%) than the high forests. The higher growing stock and the lower extraction in the high forests confirm that the high forest sequestrates significantly more carbon than the coppice with standards. Results show that thinning leads to an increase in the GE, the NUE and the WUE, and to a decrease in the RUE. Although the coppice with standards forest ecosystem exhibits higher values in all studied growth parameters, only the difference in the NUE was statistically significant. This verifies that the difference in the yield between the coppice with standards and the high forests is mainly governed by the NUE difference in stands after thinning. The coppice with standards system produces an equal amount of net primary production while consuming significantly less nitrogen (16%) compared to the high forest system. In the coppice with

Approaches to restoration of oak forests on farmed lowlands of the Mississippi River and its tributaries

Science.gov (United States)

Emile S. Gardiner; Daniel C. Dey; John A. Stanturf; Brian Roy. Lockhart

2010-01-01

The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More...

Carbon content of forest floor and mineral soil in Mediterranean Pinus spp. and Oak stands in acid soils in Northern Spain

Energy Technology Data Exchange (ETDEWEB)

Herrero, C.; Turrión, M.B.; Pando, V.; Bravo, F.

2016-07-01

Aim of the study: The aim of the study was to determine the baseline carbon stock in forest floor and mineral soils in pine and oak stands in acid soils in Northern Spain. Area of study: The study area is situated in northern Spain (42° N, 4° W) on “Paramos y Valles” region of Palencia. aterial and methods: An extensive monitoring composed of 48 plots (31 in pine and 17 in oak stands) was carried out. Litter layers and mineral soil samples, at depths of 0-30 cm and 30-60 cm, were taken in each plot. An intensive monitoring was also performed by sampling 12 of these 48 plots selected taken in account species forest composition and their stand development stage. Microbial biomass C (CMB), C mineralization (CRB), and soil organic C balance at stand level were determined in surface soil samples of intensive monitoring. Main results: No differences in soil C content were detected in the two forest ecosystems up to 60 cm depth (53.0±25.8 Mg C ha-1 in Pinus spp. plantations and 60.3±43.8 Mg C ha-1 in oak stands). However, differences in total C (CT), CMB and CRB were found in the upper 10 cm of the soils depending on the stand development stage in each species forest composition (Pinus nigra, Pinus pinaster, Pinus sylvestris and Quercus pyrenaica). Plots with high development stage exhibited significant lower metabolic quotient (qCO2), so, meant more efficient utilization of C by the microbial community. The C content in the forest floor was higher in pine stands (13.7±0.9 Mg C ha-1) than in oak stands (5.4±0.7 Mg C ha-1). A greater turnover time was found in pine ecosystems vs. oak stands. In contrast, forest floor H layer was nonexistent in oak stands. Research highlights: Results about litterfall, forest floor and mineral soil dynamics in this paper can be used strategically to reach environmental goals in new afforestation programs and sustainable forest management approaches. (Author)

Ground truth assessments of forests affected by oak decline and red oak borer in the interior highlands of Arkansas, Oklahoma, and Missouri: preliminary results from overstory analysis

Science.gov (United States)

James M. Guldin; Edward A. Poole; Eric Heitzman; John M. Kabrick; Rose-Marie Muzika

2006-01-01

Forests of the Interior Highlands of Arkansas, Oklahoma, and Missouri are being affected by oak decline and an unprecedented outbreak of a native beetle called the red oak borer. On average, Interior Highlands stands contained 236 trees per acre, of which 32 trees per acre (13.4 percent) were dead or dying. Stands averaged 97 square feet per acre of basal area, of...

CpDNA haplotype variation reveals strong human influence on oak stands of the Veluwe forest in the Netherlands

NARCIS (Netherlands)

Buiteveld, J.; Koelewijn, H.P.

2006-01-01

We examined chloroplast DNA (cpDNA) variation in 78 oak stands of an important forest complex (the Veluwe) in The Netherlands. Based on historical maps and information oak stands were classified as planted or autochthonous. A genetic study by means of cpDNA haplotype characterisation was carried out

Innovation and dedication underpin management of sudden oak death (Phytophthora ramorum) in California and Oregon forests

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Susan J. Frankel

2017-01-01

This special issue of Forest Phytophthoras serves as part of the proceedings from the Sixth Sudden Oak Death Science Symposium held June 21 -23, 2016 at Fort Mason Center in San Francisco, CA, USA. The symposium marked almost 16 years to the day that David Rizzo (UC Davis) and Matteo Garbelotto (UC Berkeley) identified the cause of sudden oak death to be a previously...

Timing fire to minimize damage in managing oak ecosystems

Science.gov (United States)

Daniel C. Dey; Callie Jo Schweitzer

2015-01-01

The long history of fire in North America spans millennia and is recognized as an important driver in the widespread and long-term dominance of oak species. Early European settlers intensified the occurrence of fire from about 1850 to 1950, with dates varying by region. This resulted in much forest damage and gained fire a negative reputation. The lack of fire for the...

Origin, development, and impact of mountain laurel thickets on the mixed-oak forests of the central Appalachian Mountains, USA

Science.gov (United States)

Patrick H. Brose

2016-01-01

Throughout forests of the northern hemisphere, some species of ericaceous shrubs can form persistent understories that interfere with forest regeneration processes. In the Appalachian Mountains of eastern North America, mountain laurel (Kalmia latifolia) may interfere in the regeneration of mixed-oak (Quercus spp.) forests. To...

Estimation of Throughfall and Stemflow Bacterial Flux in a Subtropical Oak-Cedar Forest

Science.gov (United States)

Bittar, Thais B.; Pound, Preston; Whitetree, Ansley; Moore, L. Dean; Van Stan, John T.

2018-02-01

Transport pathways of microbes between ecosystem spheres (atmosphere, phyllosphere, and pedosphere) represent major fluxes in nutrient cycles and have the potential to affect microbially mediated biogeochemical processes. Novel data on bacterial fluxes from the phyllosphere to the pedosphere during rainfall via throughfall (rain dripping from/through the canopy) and stemflow (rain funneled down tree stems) are reported. Bacterial concentrations were quantified using flow cytometry and validated with quantitative polymerase chain reaction assays in rainfall samples from an oak-cedar forest in coastal Georgia (southeastern U.S.). Bacteria concentrations (cells mL-1) and storm-normalized fluxes (cells m-2 h-1, cells m-2 mm-1) were greater for cedar versus oak. Total bacterial flux was 1.5 × 1016 cells ha-1 yr-1. These previously unexamined bacterial fluxes are interpreted in the context of major elemental pools and fluxes in forests and could represent inoculum-level sources of bacteria (if alive), and organic matter and inorganic solute inputs (if lysed) to soils.

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

Directory of Open Access Journals (Sweden)

Matthew B Dickinson

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

The response of epiphytes to anthropogenic disturbance of pine-oak forests in the highlands of Chiapas, Mexico

NARCIS (Netherlands)

Wolf, J.H.D.

2005-01-01

Epiphytes contribute up to over 30% of the vascular plant diversity of old-growth tropical rain forests, but little is known about their occurrence in exploited forests that are structurally altered. Here, I estimate epiphyte species richness and biomass on 35 oak host trees, equally divided over

Does fire affect amphibians and reptiles in eastern U.S. oak forests?

Science.gov (United States)

Rochelle B. Renken

2006-01-01

Current information about the effect of fire on amphibians and reptiles in oak forests of the Eastern and Central United States is reviewed. Current data suggest that fire results in little direct mortality of amphibians and reptiles. Fire has no effect on overall amphibian abundance, diversity, and number of species in comparisons of burned and unburned plots, though...

How does vegetation structure influence woodpeckers and secondary cavity nesting birds in African cork oak forest?

Science.gov (United States)

Segura, Amalia

2017-08-01

The Great Spotted Woodpecker provides important information about the status of a forest in terms of structure and age. As a primary cavity creator, it provides small-medium size cavities for passerines. However, despite its interest as an ecosystem engineer, studies of this species in Africa are scarce. Here, spatially explicit predictive models were used to investigate how forest structural variables are related to both the Great Spotted Woodpecker and secondary cavity nesting birds in Maamora cork oak forest (northwest Morocco). A positive association between Great Spotted Woodpecker and both dead-tree density and large mature trees (>60 cm dbh) was found. This study area, Maamora, has an old-growth forest structure incorporating a broad range of size and condition of live and dead trees, favouring Great Spotted Woodpecker by providing high availability of foraging and excavating sites. Secondary cavity nesting birds, represented by Great Tit, African Blue Tit, and Hoopoe, were predicted by Great Spotted Woodpecker detections. The findings suggest that the conservation of the Maamora cork oak forest could be key to maintaining these hole-nesting birds. However, this forest is threatened by forestry practises and livestock overgrazing and the challenge is therefore to find sustainable management strategies that ensure conservation while allowing its exploitation.

The supply and demand situation for oak timber

Science.gov (United States)

Kenneth L. Quigley

1971-01-01

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

Evaluating small mammal response to natural disturbance and restoration in oak ecosystems in the Mississippi alluvial valley

International Nuclear Information System (INIS)

Smith Carl G; Hamel Paul B; Fuzaro Gullo, Manoelle

2010-01-01

Oak species form a conspicuous and often dominant component of bottom land forests of the Mississippi Alluvial Valley. The extent of these forests has been drastically reduced as a result of clearing for agriculture in the past two centuries. Patterns of clearing have reduced the distribution of remaining forest patches to a much more flood-prone subset of the landscape than was historically the case, reducing the diversity of oak species currently present on the landscape. Intensive harvesting has further changed the composition of the remaining stands. Small remnant patches of primary forest continue to exist as Research Natural Areas on the Delta National Forest in Sharkey County, Mississippi. In particular, the Over cup Oak (Quercus lyrata) and Redgum (Liquidambar styraciflua) Research Natural Areas pres ent substantial components of the trees for which the areas were named, as well as Quercus nuttallii and smaller components of other species. Recent interest in afforestation has produced a resurgence of interest in restoration of oak forest to abandoned farmland in the region. We have studied small mammal response to restoration on an extensive experiment near the Delta National Forest since 1995. We have also examined small mammal response to a tornado that disturbed approximately half of the Over cup Oak Research Natural Area in 2008. We use these studies to demonstrate how population estimates of small mammals can be obtained from capture-recapture studies, employing different designs, and utilizing Program Capture for population estimation. Small mammal communities in these stands are more species-rich in early succession than in primary forest. The study of response to tornado damage to the Over cup Oak Research Natural Area is complicated by the fact that this particular forest type is very flood-prone, creating obstacles to colonization by small mammals. Analysis of capture-recapture data with robust methods illustrated in this study permits extraction

Macromycetes of oak-lime-hornbeam woods in the Niepołomice Forest near Kraków (S Poland - monitoring studies

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Władysława Wojewoda

2014-08-01

Full Text Available In the years 1994-1996 studies on macromycetes of the Niepołomice Forest near Kraków were made in four plots designated in deciduous forests (Tilio-Carpinetum stachyetosum with a population of Carpinus betulus, Quercus robur and Tilia cordata (the size of each plot was 1000 m2. The observations were made through an international project "Mycological monitoring in European oak forests". As many as 274 species were recorded, including 234 saprobic, 33 mycorrhizal, and 7 parasitic fungi. Moreover, 15 species of fungi are connected with oak, 24 species of fungi are threatened, and 16 species are new to Poland.

A greenhouse study of northern red oak seedling growth on two forest soils at different stages of acidification

International Nuclear Information System (INIS)

Sharpe, W.E.; Swistock, B.R.; Dewalle, D.R.

1993-01-01

The objective of this study was to determine whether or not Ca and P in soils from two forested sites at two different stages of acidification were limiting growth of red oak seedlings. The A and E horizons of a Berks soils from Watershed 4 at the Fernow Experimental Forest (cation exchange buffer range) and a Hazelton-Dekalb soil from Pea Vine Hill in Southwestern Pennsylvania (A1 buffer range) were placed in pots and utilized as the growth medium for northern red oak seedlings in a greenhouse environment. Soil water NO 3 -N, Ca, Mg and K concentrations were significantly higher on the Berks soil. Soil exchangeable P and soil solution TP (total phosphorus) were significantly higher on the Hazelton-Dekalb soil. Both soils were amended with bone meal (CaPO 4 ) to determine the effects of Ca and P addition on the growth and nutrient uptake of the seedlings. Height growth of the control red oak seedlings was significantly greater on the Berks soil after 45 d, but amendment of Hazelton-Dekalb soils with bone meal eliminated this difference. Bone meal addition to the Hazelton-Dekalb soil resulted in significantly greater height growth of red oak seedlings when compared to red oak seedings grown on unamended Hazelton-Dekalb soil, but did not have a similar effect for red oak seedlings grown on Berks soil. Bone meal addition to Hazelton-Dekalb soil resulted in greater concentrations of Ca and Mg in red oak leaves. Unfertilized Berks red oak seedling leaves had significantly higher concentrations of Ca and K than their Hazelton-Dekalb counterparts. Al-Ca molar ratios were significantly lower on the Berks soil. Red oak height growth was increased significantly by Ca addition to the Hazelton-Dekalb soil. 24 refs., 2 figs., 8 tabs

Comparison of vegetation patterns and soil nutrient relations in an oak-pine forest and a mixed deciduous forest on Long Island, New York

Energy Technology Data Exchange (ETDEWEB)

Peterson, S.C.; Curtis, P.S.

1980-11-01

An analysis of soil nutrient relations in two forest communities on Long Island, NY, yielded a correlation between the fertility of the top-soil and vegetational composition. The oak-pine forest soils at Brookhaven National Laboratory contain lower average concentrations of NH/sub 3/, Ca, K, and organic matter than the mixed deciduous forest soils in the Stony Brook area. The pH of the topsoil is also more acidic at Brookhaven. The observed differences between localities are greater than within-locality differences between the two soil series tested (Plymouth and Riverhead), which are common to both localities. Nutrient concentrations in the subsoil are not consistently correlated with either locality or soil series, although organic matter and NH/sub 3/ show significantly higher concentrations at Stony Brook. Supporting data on density and basal area of trees and coverage of shrubs and herbs also reveals significant variation between the two forest communities. An ordination of the vegetation data shows higher similarity within than between localities, while no obvious pattern of within-locality variation due to soil series treatments is apparent. These data support the hypothesis that fertility gradients may influence forest community composition and structure. This hypothesis is discussed with reference to vegetation-soil interactions and other factors, such as frequency of burning, which may direct the future development of the Brookhaven oak-pine forest.

Sudden Oak Death in redwood forests: vegetation dynamics in the wake of tanoak decline

Science.gov (United States)

Benjamin Ramage; Kevin O’Hara

2010-01-01

Numerous lines of inquiry have concluded that tanoak (Lithocarpus densiflorus) will continue to experience drastic population declines and may even disappear entirely from redwood (Sequoia sempervirens) forests as a result of the exotic disease sudden oak death (SOD) (Maloney and others 2005, McPherson and others 2005,...

Sympatric parallel diversification of major oak clades in the Americas and the origins of Mexican species diversity.

Science.gov (United States)

Hipp, Andrew L; Manos, Paul S; González-Rodríguez, Antonio; Hahn, Marlene; Kaproth, Matthew; McVay, John D; Avalos, Susana Valencia; Cavender-Bares, Jeannine

2018-01-01

Oaks (Quercus, Fagaceae) are the dominant tree genus of North America in species number and biomass, and Mexico is a global center of oak diversity. Understanding the origins of oak diversity is key to understanding biodiversity of northern temperate forests. A phylogenetic study of biogeography, niche evolution and diversification patterns in Quercus was performed using 300 samples, 146 species. Next-generation sequencing data were generated using the restriction-site associated DNA (RAD-seq) method. A time-calibrated maximum likelihood phylogeny was inferred and analyzed with bioclimatic, soils, and leaf habit data to reconstruct the biogeographic and evolutionary history of the American oaks. Our highly resolved phylogeny demonstrates sympatric parallel diversification in climatic niche, leaf habit, and diversification rates. The two major American oak clades arose in what is now the boreal zone and radiated, in parallel, from eastern North America into Mexico and Central America. Oaks adapted rapidly to niche transitions. The Mexican oaks are particularly numerous, not because Mexico is a center of origin, but because of high rates of lineage diversification associated with high rates of evolution along moisture gradients and between the evergreen and deciduous leaf habits. Sympatric parallel diversification in the oaks has shaped the diversity of North American forests. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Using aerial photography to estimate wood suitable for charcoal in managed oak forests

Science.gov (United States)

Ramírez-Mejía, D.; Gómez-Tagle, A.; Ghilardi, A.

2018-02-01

Mexican oak forests (genus Quercus) are frequently used for traditional charcoal production. Appropriate management programs are needed to ensure their long-term use, while conserving the biodiversity and ecosystem services, and associated benefits. A key variable needed to design these programs is the spatial distribution of standing woody biomass. A state-of-the-art methodology using small format aerial photographs was developed to estimate the total aboveground biomass (AGB) and aboveground woody biomass suitable for charcoal making (WSC) in intensively managed oak forests. We used tree crown area (CAap) measurements from very high-resolution (30 cm) orthorectified small format digital aerial photographs as the predictive variable. The CAap accuracy was validated using field measurements of the crown area (CAf). Allometric relationships between: (a) CAap versus AGB, and (b) CAap versus WSC had a high significance level (R 2 > 0.91, p < 0.0001). This approach shows that it is possible to obtain sound biomass estimates as a function of the crown area derived from digital small format aerial photographs.

Forest meteorology research within the Oak Ridge site, eastern deciduous forest biome, USIBP

International Nuclear Information System (INIS)

Hutchison, B.A.; Matt, D.R.

1977-01-01

The data presented here indicate that the diurnal trends in forest microclimate are dominated by the diurnal trend in incident solar radiation amounts and the diurnal changes in solar elevations. Absolute values of these microclimatic variables, on the other hand, reflect strongly, the synoptic climatic conditions present and, to a lesser degree, the interactions among synoptic climatic parameters, forest structure, forest physiology, and soil moisture conditions. The seasonal changes in forest microclimate are the result of changes in incident radiation amounts, earth-sun geometry, and phenological change in forest structure along with seasonal changes in synoptic climatic parameters. The temporal and spatial variations of solar radiation within and above a deciduous forest composed predominately of tulip poplar (biriodendron tulipifera) were documented and on attempt was made to relate the variations to forest structure

Winning and losing tree species of reassembly in Minnesota's mixed and broadleaf forests.

Directory of Open Access Journals (Sweden)

Brice B Hanberry

Full Text Available We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota's mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive species on mesic sites. The proportion of shade-tolerant species increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity.

Winning and losing tree species of reassembly in Minnesota's mixed and broadleaf forests.

Science.gov (United States)

Hanberry, Brice B; Palik, Brian J; He, Hong S

2013-01-01

We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota's mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive species on mesic sites. The proportion of shade-tolerant species increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity.

Disking and mid- and understory removal following an above-average acorn crop in three mature oak forests in southern Indiana

Science.gov (United States)

Ronald A. Rathfon; Nathanael I. Lichti; Robert K. Swihart

2008-01-01

We disked using small-scale equipment in the understory of three mature upland oak (Quercus) forests in southern Indiana immediately following acorn dispersal in an aboveaverage seed crop year as a means of improving oak seedling establishment. Three different mid- and understory removal treatments were also applied to create favorable light...

Winning and Losing Tree Species of Reassembly in Minnesota’s Mixed and Broadleaf Forests

Science.gov (United States)

Hanberry, Brice B.; Palik, Brian J.; He, Hong S.

2013-01-01

We examined reassembly of winning and losing tree species, species traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing species by changes in composition, distribution, and site factors between historical and current surveys in Minnesota’s mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant tree species. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive species on mesic sites. The proportion of shade-tolerant species increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity. PMID:23613911

Assessing the Cost of an Invasive Forest Pathogen: A Case Study with Oak Wilt

Science.gov (United States)

Haight, Robert G.; Homans, Frances R.; Horie, Tetsuya; Mehta, Shefali V.; Smith, David J.; Venette, Robert C.

2011-03-01

Economic assessment of damage caused by invasive alien species provides useful information to consider when determining whether management programs should be established, modified, or discontinued. We estimate the baseline economic damage from an invasive alien pathogen, Ceratocystis fagacearum, a fungus that causes oak wilt, which is a significant disease of oaks ( Quercus spp.) in the central United States. We focus on Anoka County, Minnesota, a 1,156 km2 mostly urban county in the Minneapolis-Saint Paul metropolitan region. We develop a landscape-level model of oak wilt spread that accounts for underground and overland pathogen transmission. We predict the economic damage of tree mortality from oak wilt spread in the absence of management during the period 2007-2016. Our metric of economic damage is removal cost, which is one component of the total economic loss from tree mortality. We estimate that Anoka County has 5.92 million oak trees and 885 active oak wilt pockets covering 5.47 km2 in 2007. The likelihood that landowners remove infected oaks varies by land use and ranges from 86% on developed land to 57% on forest land. Over the next decade, depending on the rates of oak wilt pocket establishment and expansion, 76-266 thousand trees will be infected with discounted removal cost of 18-60 million. Although our predictions of removal costs are substantial, they are lower bounds on the total economic loss from tree mortality because we do not estimate economic losses from reduced services and increased hazards. Our predictions suggest that there are significant economic benefits, in terms of damage reduction, from preventing new pocket establishment or slowing the radial growth of existing pockets.

A neighborhood analysis of the consequences of Quercus suber decline for regeneration dynamics in Mediterranean forests.

Directory of Open Access Journals (Sweden)

Beatriz Ibáñez

Full Text Available In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber. Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species' relative abundance and canopy trees' health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current

Understory response to varying fire frequencies after 20 years of prescribed burning in an upland oak forest

Science.gov (United States)

Burton, J.A.; Hallgren, S.W.; Fuhlendorf, S.D.; Leslie, David M.

2011-01-01

Ecosystems in the eastern United States that were shaped by fire over thousands of years of anthropogenic burning recently have been subjected to fire suppression resulting in significant changes in vegetation composition and structure and encroachment by invasive species. Renewed interest in use of fire to manage such ecosystems will require knowledge of effects of fire regime on vegetation. We studied the effects of one aspect of the fire regime, fire frequency, on biomass, cover and diversity of understory vegetation in upland oak forests prescribe-burned for 20 years at different frequencies ranging from zero to five fires per decade. Overstory canopy closure ranged from 88 to 96% and was not affected by fire frequency indicating high tolerance of large trees for even the most frequent burning. Understory species richness and cover was dominated by woody reproduction followed in descending order by forbs, C3 graminoids, C4 grasses, and legumes. Woody plant understory cover did not change with fire frequency and increased 30% from one to three years after a burn. Both forbs and C3 graminoids showed a linear increase in species richness and cover as fire frequency increased. In contrast, C4 grasses and legumes did not show a response to fire frequency. The reduction of litter by fire may have encouraged regeneration of herbaceous plants and helped explain the positive response of forbs and C3 graminoids to increasing fire frequency. Our results showed that herbaceous biomass, cover, and diversity can be managed with long-term prescribed fire under the closed canopy of upland oak forests. ?? 2011 Springer Science+Business Media B.V.

Remnant large 'rescue' trees enhance epiphyte resilience to anthropogenic disturbance of pine-oak forests in the Highlands of Chiapas, Mexico

NARCIS (Netherlands)

Wolf, J.H.D.

2006-01-01

I studied vascular epiphytes in 16 pine-oak forest fragments within an 400 km2 relatively flat area at c. 2300 m elevation on an extended gradient of anthropogenic disturbance. Epiphyte biomass and species richness on 35 oak host trees in six diameter classes varied between the sites from 0.8 to 243

Scandinavian Participatory Design

DEFF Research Database (Denmark)

Iversen, Ole Sejer; Smith, Rachel Charlotte

2012-01-01

As Scandinavian Participatory Design (PD) approach is a highly values-led design approach, and is gaining importance in IDC research, we discuss the underlying values of democracy, quality of work and emancipation of this approach. We present a case study, Digital Natives, in which the Scandinavian...... PD approach was put into practice. Here we involved seven teenagers in the design of an interactive museum exhibition. We discuss how this particular approach effects key design activities such as the establishment of the design space, power relations among participants, the dialogical design process......, project evaluation and the final outcome of the project. We conclude that the end goal of Scandinavian PD is not necessarily the final research prototype. Rather, in Scandinavian PD, designers strive to provide children with meaningful alternatives to existing technologies. It is to help children realize...

Scandinavian Cooperative Advantage

DEFF Research Database (Denmark)

Strand, Robert; Freeman, R. Edward

2015-01-01

. We conclude by endorsing the expression “Scandinavian cooperative advantage” in an effort to draw attention to the Scandinavian context and encourage the field of strategic management to shift its focus from achieving a competitive advantage toward achieving a cooperative advantage....

Impacts of Phytophthora ramorum on oaks and tanoaks in Marin County, California forests since 2000

Science.gov (United States)

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

2010-01-01

The forests of Marin County were among the first in coastal California to be affected by the Phytophthora ramorum epidemic. Although initially observed in 1994 in tanoaks (Lithocarpus densiflorus) and 1995 in coast live oaks (Quercus agrifolia), it is evident from studies of disease progression that the...

Photo guide for estimating risk to hardwood trees during prescribed burning operations in eastern oak forests

Science.gov (United States)

Patrick H. Brose

2009-01-01

A field guide of 40 photographs of common hardwood trees of eastern oak forests and fuel loadings surrounding their bases. The guide contains instructions on how to rapidly assess a tree's likelihood to be damaged or killed by prescribed burning.

Fire frequency effects on fuel loadings in pine-oak forests of the Madrean Province

Science.gov (United States)

Francisco J. Escobedo; Peter F. Ffolliott; Gerald J. Gottfried; Florentino Garza

2001-01-01

Loadings of downed woody fuels in pine-oak forests of the Madrean Province are heavier on sites in southeastern Arizona with low fire frequencies and lower on sites in northeastern Sonora, Mexico, with high fire frequencies. Low fire frequencies in southeastern Arizona are attributed largely to past land uses and the fire suppression policies of land management...

Scandinavian Participatory Design

DEFF Research Database (Denmark)

Iversen, Ole Sejer; Smith, Rachel Charlotte

2012-01-01

As Scandinavian Participatory Design (PD) approach is a highly values-led design approach, and is gaining importance in IDC research, we discuss the underlying values of democracy, quality of work and emancipation of this approach. We present a case study, Digital Natives, in which the Scandinavian...

Concentrations and fluxes of isoprene and oxygenated VOCs at a French Mediterranean oak forest

International Nuclear Information System (INIS)

Kalogridis, C.; Gros, V.; Sarda-Esteve, R.; Bonsang, B.; Bonnaire, N.; Boissard, C.; Baisnee, D.; Lathiere, J.

2014-01-01

The CANOPEE project aims to better understand the biosphere-atmosphere exchanges of biogenic volatile organic compounds (BVOCs) in the case of Mediterranean ecosystems and the impact of in-canopy processes on the atmospheric chemical composition above the canopy. Based on an intensive field campaign, the objective of our work was to determine the chemical composition of the air inside a canopy as well as the net fluxes of reactive species between the canopy and the boundary layer. Measurements were carried out during spring 2012 at the field site of the Oak Observatory of the Observatoire de Haute Provence (O3HP) located in the southeast of France. The site is a forest ecosystem dominated by downy oak, Quercus pubescens Willd., a typical Mediterranean species which features large isoprene emission rates. Mixing ratios of isoprene, its degradation products methylvinylketone (MVK) and methacrolein (MACR) and several other oxygenated VOC (OxVOC) were measured above the canopy using an online proton transfer reaction mass spectrometer (PTR-MS), and fluxes were calculated by the disjunct eddy covariance approach. The O3HP site was found to be a very significant source of isoprene emissions, with daily maximum ambient concentrations ranging between 2-16 ppbv inside and 2-5 ppbv just above the top of the forest canopy. Significant isoprene fluxes were observed only during daytime, following diurnal cycles with midday net emission fluxes from the canopy ranging between 2.0 and 9.7 mgm -2 h -1 . Net isoprene normalized flux (at 30 C, 1000 μmol quantam -2 s -1 ) was estimated at 7.4 mgm -2 h -1 . Evidence of direct emission of methanol was also found exhibiting maximum daytime fluxes ranging between 0.2 and 0.6 mgm -2 h -1 , whereas flux values for monoterpenes and others OxVOC such as acetone and acetaldehyde were below the detection limit. The MVK+MACR-to-isoprene ratio provided useful information on the oxidation of isoprene, and is in agreement with recent findings

The historical significance of oak

Science.gov (United States)

J. V. Thirgood

1971-01-01

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

Oak regeneration potential increased by shelterwood treatments

Science.gov (United States)

Richard C. Schlesinger; Ivan L. Sander; Kenneth R. Davidson

1993-01-01

In much of the Central Hardwood Forest Region, oak species are not regenerating well, even though large oak trees are common within the existing forests. The shelterwood method has been suggested as a potential tool for establishing and developing advanced regeneration where it is lacking. The 10-yr results from a study of several variants of the shelterwood method...

Consumption and reaccumulation of forest fuels in oak shelterwood stands managed with prescribed fire

Science.gov (United States)

Patrick H. Brose

2016-01-01

In the shelterwood-burn technique, a moderate- to high-intensity growing-season prescribed fire is essential to achieve desired oak regeneration goals. These levels of fire intensity are dependent on the increased fuel loadings created by the preceding first removal cut. However, the loadings of forest fuels and their fluctuation during implementation of the...

An evaluation of seven methods for controlling mountain laurel thickets in the mixed-oak forests of the central Appalachian Mountains, USA

Science.gov (United States)

Patrick H. Brose

2017-01-01

In the Appalachian Mountains of eastern North America, mountain laurel (Kalmia latifolia) thickets in mixed-oak (Quercus spp.) stands can lead to hazardous fuel situations, forest regeneration problems, and possible forest health concerns. Therefore, land managers need techniques to control mountain laurel thickets and limit...

Species-specific Mechanisms Contributing to the Mesophication of Upland Oak Stands in the Absence of Fire

Science.gov (United States)

Babl, E. K.; Alexander, H. D.; Siegert, C. M.; Willis, J. L.; Berry, A. I.

2017-12-01

Upland oak forests of the eastern United States are shifting dominance towards shade-tolerant, fire-intolerant species. This shift is hypothesized to be driven by anthropogenic fire suppression and lead to mesophication, a positive feedback loop where shade-tolerant, fire-sensitive species (i.e. mesophytes) create a cool, moist understory, reducing forest flammability and promoting their own proliferation at the expense of pyrophytic, shade-intolerant species such as oaks. There have been few empirical studies identifying mechanisms of mesophication, and these studies have yet to extensively explore potential mesophytes other than red maple (Acer rubrum). To address this issue, we sampled four hypothesized mesophytes (A. rubrum, A. saccharum, Carya glabra, and Fagus grandifolia) and two upland oak species (Quercus alba and Q. montana) across a gradient of sizes (20-60 cm DBH) in western Kentucky. We quantified canopy, bark, and leaf litter traits among upland oaks and mesophytes that may lead to differences in forest flammability. Preliminary results show that mesophytes had thinner and smoother bark than upland oaks and an increased canopy volume (normalized to stem volume), traits known to influence water movement through the canopy and understory microclimate. Maple leaf litter also decomposed faster, which could decrease fuel loads; after 6 months, red and sugar maple leaf litter lost 37% of original mass compared to 32%, 22%, and 14% mass loss in hickory, oak, and American beech litter, respectively. Furthermore, volumetric soil moisture of the soil organic layer beneath the canopies of mesophytes was 62% moister two days following a rainfall event compared to oaks. These differences in soil organic layer water retention after rainfall could lead to fuel discontinuity. These findings suggest that mesophytes may alter future forest flammability through their bark, canopy, and leaf litter traits which may modify fuel moisture, loads, and continuity and that a

Modeling the effects of harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape

Science.gov (United States)

Wen J. Wang; Hong S. He; Martin A. Spetich; Stephen R. Shifley; Frank R. III Thompson; Jacob S. Fraser

2013-01-01

Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest...

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

Science.gov (United States)

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

2007-01-01

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

Fire Frequency and Vegetation Composition Influence Soil Nitrogen Cycling and Base Cations in an Oak Savanna Ecosystem

Science.gov (United States)

McLauchlan, K. K.; Nelson, D. M.; Perakis, S.; Marcotte, A. L.

2017-12-01

Fire frequency is crucial for maintaining savannas in the transition between forests and grasslands. In general, increasing fire frequency has two effects: it increases herbaceous plant cover more than woody plant cover, and it lowers soil organic matter stocks. These effects have been demonstrated at a long-term prescribed fire experiment in an oak savanna ecosystem at Cedar Creek Ecosystem Science Reserve, Minnesota, U.S.A. The fire experiment began in 1964 and oak savannas are burned at various frequencies ranging from every year to not at all. This has led to changes in vegetation ranging from almost 100% grassland to 100% oak forest. Additionally, nitrogen stocks almost doubled in the sites that were not burned, as it accumulated in the trees, leaf litter, and soil. We addressed additional soil changes taking place at this experiment by asking the question: How have fire and oak-grass balance affected soil nutrients, specifically nitrogen and base cations? Surface soils were collected from 12 plots on the oak savanna burn experiment. Soils were collected in increments to 100 cm depth, from under grass-dominated vegetation and from under tree-dominated vegetation. We non-destructively estimated soil base cations by measuring elemental concentrations of dried soil subsamples with a handheld x-ray fluorescence analyzer. We also measured carbon and nitrogen concentrations and isotopic composition of the soil samples. Soils in plots with high fire frequency had higher concentrations of calcium than soils in unburned plots (low fire frequency). Similar trends were seen for soil potassium, magnesium, and phosphorus concentrations. In contrast, soils in plots with high fire frequency had dramatically lowered nitrogen cycling rates and stocks across the oak savanna. The contrast between the responses of different nutrients to changing fire frequency has important implications for the consequences of fire and tree-grass composition on nutrient cycling dynamics.

Spatial patterning of fuels and fire hazard across a central U.S. deciduous forest region

Science.gov (United States)

Michael C. Stambaugh; Daniel C. Dey; Richard P. Guyette; Hong S. He; Joseph M. Marschall

2011-01-01

Information describing spatial and temporal variability of forest fuel conditions is essential to assessing overall fire hazard and risk. Limited information exists describing spatial characteristics of fuels in the eastern deciduous forest region, particularly in dry oak-dominated regions that historically burned relatively frequently. From an extensive fuels survey...

Hyperdiversity of ectomycorrhizal fungus assemblages on oak seedlings in mixed forests in the southern Appalachian Mountains

Science.gov (United States)

John F. Walker; Orson K. Miller; Jonathan L. Horton

2005-01-01

Diversity of ectotrophic mycobionts on outplanted seedlings of two oak species (Quercus rubra and Quercus prinus) was estimated at two sites in mature mixed forests in the southern Appalachian Mountains by sequencing nuclear 5.8S rRNA genes and the flanking internal transcribed spacer regions I and II (ITS). The...

Microsatellite Primer Development for Post Oak, Quercus stellata (Fagaceae

Directory of Open Access Journals (Sweden)

Warren B. Chatwin

2014-10-01

Full Text Available Premise of the study: The American Cross Timbers forest ecosystem runs from southeastern Kansas to Central Texas and is primarily composed of post oak (Quercus stellata. This old-growth forest currently occupies only about 2% of its ancestral range. To facilitate genetic research on this species, we developed microsatellite primers specific to post oak from reduced genomic libraries. Methods and Results: Two Q. stellata individuals, sampled from the northern and southern range of the post oak forest, were subject to genomic reduction and 454 pyrosequencing. Bioinformatic analysis identified putative microsatellites from which 12 polymorphic primer sets were screened on three populations. The number of alleles observed ranged from five to 20 across all populations, while observed and expected heterozygosity values ranged from 0.05 to 0.833 and 0.236 to 0.893, respectively, within individual populations. Conclusions: We report the development of microsatellite markers, specific to post oak, to aid the study of genetic diversity and population structure of extant forest remnants.

Phenophases alter the soil respiration-temperature relationship in an oak-dominated forest

Science.gov (United States)

Jared L. DeForest; Askoo Noormets; Steve G. McNulty; Ge Sun; Gwen Teeney; Jiquan Chen

2006-01-01

Soil respiration (SR) represents a major component of forest ecosystem respiration and is influenced seasonally by environmental factors such as temperature, soil moisture, root respiration, and litter fall. Changes in these environmental factors correspond with shifts in plant phenology. In this study, we examined the relationship between canopy phenophases @re-growth...

The Turkey oak high forests in the Molise region (central Italy. Analysis of past silvicultural system and current management choices.

Directory of Open Access Journals (Sweden)

Paolo Cantiani

2010-12-01

Full Text Available Normal 0 14 false false false MicrosoftInternetExplorer4 Aim of the work is to provide further knowledge on the silvicultural system applied to Quercus cerris hight forests in the Molise Region (Central Italy. An historical analysis, based on a number of forest management plans applied since 1940 referred to 19 municipalities and on other historical documents, is provided in the paper. Forest management has been traditionally applied in the Molise Region and therefore is at now possible to reconstruct in detail the management of the forests of Molise Region. The historical study has been integrated with the analysis of a chronosequence including four steps of stand development in a Turkey oak stand: the regeneration phase (1-2 yrs - the unthinned young stand (46 yrs - the unthinned adult stand (aged 60 to 100 - the mature stand (126 yrs. Mensurational surveys were carried out at each phase in order to characterize both stand structure and derive information on the silvicultural practices applied in the past, but not documented in the available papers. The stand age was determined by tree coring and count of annual rings. At the beginning of the last century, the silvicultural system to be applied in oak high forests wasn’t strictly defined and a particular kind of selection cutting was carried out. It was named taglio a salto per sezioni i.e. “compartment selection cutting”, partly leading back to a real selection cutting, partly to a shelterwood system. The use of the reported silvicultural system gave rise to irregular forest structures and led to management problems well-described in the management plans at the end of 1940s. Another consequence of the applied practices was the absence or the inadequate natural regeneration establishment. The contemporary unregulated practice of grazing the forest floor contributed to the unsuccessful regeneration and made the situation worse. The presence of an understorey layer made up by sproutings

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

Science.gov (United States)

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

2008-01-01

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

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

Science.gov (United States)

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

2013-01-01

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

Climate change impact on a mixed lowland oak stand in Serbia

Directory of Open Access Journals (Sweden)

Dejan Stojanović

2015-12-01

Full Text Available Climatic changes and bad environmental conditions may lead to forests vitality loss and even mortality. This is the reason why increased sanitary felling operations were performed in mixed oak forests in northern Serbia in 2013 in order to solve the severe dieback which affected some Pedunculate oak (Quercus robur L. and Turkey oak (Quercus cerris L. stands, after the very dry years 2011 and 2012.Dendrochronological techniques were applied to both these oak species collected in a stand, to examine the impact of temperature, precipitation and ground water level on forest growth and investigate the potential causes of the dieback.Differences in tree-ring patterns between surviving and dead trees were not significant according to t-value (from 5.68 to 14.20 and Gleichläufigkeit coefficient (from 76% to 82%, this meaning no distinctive responses of the two ecologically different oak species. As for radial increment, pedunculate and Turkey oak trees showed a similar response to environmental variables in this mixed stand. The Simple Pearson’s correlation analysis, which was conducted, showed that among three basic environmental variables (the mean monthly air temperature, the monthly sum of precipitation and the mean monthly water level, proxy of ground water level, the water level of Danube river in May and the temperature in April were statistically related to the growth of the four tree groups: (i pedunculate oak vital, (ii pedunculate oak dead, (iii Turkey oak vital and (iv Turkey oak dead trees, for the period 1961-2010 (p<0.05, n=60. Similar phenomena had already been observed in the Sava River basin for the growth of pure pedunculate oak forests. The long-term decline of the Danube River water level may be related to climate variations and to the changes of water management, river bed, as well as land-use. Together with the increase of temperature, this decline of the water level, and its potential unavailability in the soil, represents a

Can root biomass of white oak advance regeneration be reliably predicted from diameter and height?

Science.gov (United States)

Benjamin O. Knapp; G. Geoff Wang; Joan L. Walker; David H. van Lear

2006-01-01

The successful regeneration of oak-dominated stands is an issue of concern for foresters today. The size of the root system is directly related to the rate of growth following release and therefore to the chances of establishment of regrowth. The size of the root system is difficult to measure without destructive sampling, but it may be assessed through modeling. The...

Effects of Thinning Intensities on Soil Infiltration and Water Storage Capacity in a Chinese Pine-Oak Mixed Forest

OpenAIRE

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning):

The Society for Scandinavian Art

DEFF Research Database (Denmark)

Grand, Karina Lykke

2016-01-01

The Society for Nordic Art & the Scandinavian Society [Selskabet for Nordisk Kunst & Skandinavisk Selskab]......The Society for Nordic Art & the Scandinavian Society [Selskabet for Nordisk Kunst & Skandinavisk Selskab]...

The Scandinavian Approach to the Experience Economy

DEFF Research Database (Denmark)

Bille, Trine

2012-01-01

This article discusses the concept of experience economy in a Scandinavian context and shows how the Scandinavian version of the concept has come about from a mix of three different approaches and theories. In the Scandinavian countries, the experience economy has been developed in a political...... context and is apparently a popular development policy for local government authorities and regions. The Scandinavian definition links the experience economy closely with cultural activities, and to the expectation of economic return and economic development. This article discusses the Scandinavian...

Monitoring endophyte populations in pine plantations and native oak forests in Northern Spain

Energy Technology Data Exchange (ETDEWEB)

Martinez-Alvarez, P.; Martin-Garcia, J.; Rodriguez-Ceinos, S.; Diez, J. J.

2012-07-01

The replacement of native forest with plantations of other species may have important impacts on ecosystems. Some of these impacts have been widely studied, but very little is known about the effects on fungal communities and specifically endo phytic fungi. In this study, endophyte assemblages in pine plantations (Pinus sylvestris, P. nigra and P. pinaster) and native oak forests (Quercus pyrenaica) in the north of the province of Palencia (Spain) were analyzed. For this purpose, samples of needles/leaves and twigs were collected from three trees in each of three plots sampled per host species. The samples were later processed in the laboratory to identify all of the endo phytic species present. In addition, an exhaustive survey was carried out of the twelve sites to collect data on the environmental, crown condition, dendrometric and soil variables that may affect the distribution of the fungi. The endophyte assemblages isolated from P. sylvestris and P. nigra were closely related to each other, but were different from those isolated from P. pinaster. The endophytes isolated from Q. pyrenaica were less closely related to those from the other hosts, and therefore preservation of oak stands is important to prevent the loss of fungal diversity. Finally, the distribution of the endophyte communities was related to some of the environmental variables considered. (Author) 42 refs.

Phytosociological characteristics of forest vegetation NPR Dubnik

International Nuclear Information System (INIS)

Hrabovsky, A.; Balkovic, J.; Kollar, J.

2010-01-01

National Wildlife (NPR) Dubnik represents a unique fragment of natural forest vegetation in the region of Nitra loess upland. Status of oak and oak-hornbeam forests in this book was last documented in 1965. The aim of the contribution is to assess the current status of forest vegetation in the NPR Dubnik by modern methods of phytosociology in accordance with current thinking on the classification of oak and oak-hornbeam forests.

Red maple (Acer rubrum) response to prescribed burning on the William B. Bankhead National Forest, Alabama

Science.gov (United States)

Stacy L. Clark; Callie Jo Schweitzer

2013-01-01

Prescribed burning is used as a management tool on national forests in the Southeastern United States to maintain oak (Quercus spp.) -dominated forest or woodland habitat. Few studies have examined response to burning at the stand, plot, and tree level. We documented red maple (Acer rubrum) response to dormant-season prescribed...

Reconstructing the competitive dynamics of mixed-oak neighborhoods

Science.gov (United States)

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

2012-01-01

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

A δ(15)N assessment of nitrogen deposition for the endangered epiphytic orchid Laelia speciosa from a city and an oak forest in Mexico.

Science.gov (United States)

Díaz-Álvarez, Edison A; Reyes-García, Casandra; de la Barrera, Erick

2016-09-01

Atmospheric nitrogen deposition poses a major threat to global biodiversity. Tropical epiphytic plants are especially at risk given their reliance on atmospheric sources of nutrients. The leaf, pseudobulb, and root carbon and nitrogen content, C:N ratio, as well as the nitrogen isotopic composition were studied for individuals of Laelia speciosa from a city and from an oak forest in Mexico. The nitrogen content of leaves was similar between the city and the oak forest, reaching 1.3 ± 0.2 % (dry mass). The δ(15)N of leaves, pseudobulbs, and roots reached 5.6 ± 0.2 ‰ in the city, values found in sites exposed to industrial and vehicular activities. The δ(15)N for plant from the oak forest amounted to -3.1 ± 0.3 ‰, which is similar to values measured from sites with low industrial activities. Some orchids such as Laelia speciosa produce a single pseudobulb per year, i.e., a water and nutrient storage organ, so the interannual nitrogen deposition was studied by considering the ten most recent pseudobulbs for plants from either site formed between 2003 and 2012. The C:N ratio of the ten most recent pseudobulbs from the oak forest, as well as that of the pseudobulbs formed before 2010 for plants in the city were indistinguishable from each other, averaging 132.4 ± 6.5, while it was lower for the two most recent pseudobulbs in the city. The δ(15)N values of pseudobulbs from the oak forest averaged ‒4.4 ± 0.1 ‰ for the entire series. The δ(15)N ranged from 0.1 ± 1.6 ‰ for the oldest pseudobulb to 4.7 ± 0.2 ‰ for the pseudobulb formed in the city from 2008 onwards. Isotopic analysis and the C:N ratio for L. speciosa revealed that rates of nitrogen deposition were higher in the city than in the forest. The δ(15)N values of series of pseudobulbs showed that it is possible to track nitrogen deposition over multiple years.

An approximation to the fauna associated with oak forests of Guantiva- La Rusia - Iguaque corridor (Boyaca-Santander, Colombia)

International Nuclear Information System (INIS)

Saenz Jimenez, Fausto Alexis

2010-01-01

There were 380 species of vertebrates in the Guantiva - La Rusia - Iguaque corridor, distributed in 256 birds, 83 mammals, 31 amphibians and 10 reptiles. Twenty correspond to endangered species (10 amphibians, 8 birds and 2 mammals), 28 to endemic species (21 amphibians, 5 birds and 3 mammals) and 15 to migratory bird species. One hundred and three species were associated with oak forests of the corridor; comprising 62 birds, 18 mammals, 22 amphibians and 1 reptile species. Birds of the families Cracidae, Grallaridae, Phasianidae, Picidae, Psittacidae Trogonidae, mammals of the families Phyllostomidae, Sciuridae, Centrolenidae and amphibians of the family Strabomantidae had the highest number of species associated with oak. The amphibians were most frequently associated with these ecosystems, since 58% of the species of this group have a preference for habitats with oak presence.

Spatio-temporal analysis of oak forests (Quercus humboldtii Bonpl.) change and its relationship with pottery at Aguabuena (Raquira-Boyaca)

International Nuclear Information System (INIS)

Moncada Rasmussen, Dora Maria

2010-01-01

This research was conducted at Aguabuena, Raquira-Boyaca, and the main objective was to identify the changes in the settlement patterns and oak - forest cover, due to the development of new technologies and destinies for ceramics production. The study was carried out using aerial photographs from 1985 and 1993 processed in ArcGIS v. 9.0, as well as the application of participatory methods and spatial statistics. The spatio-temporal analysis of the forests allowed the measurement of perimeter and area changes and the number of fragments, where the loss of forest cover was 43.43% for the evaluated years. For analytical purposes related to the ceramics production organization, two different types of workshops can be pointed out: Domestic and Family - Industry. In the Domestic workshops spatial aggregation is due to the forest presence, its relative and different antiquity. The family - indus try- workshops are located along roads, for their relatives and population increment. Each ceramic production system represents different forms of relations with nature; the domestic ones are located in the oaks forests, using high quality fuel in the heating ceramics, while the Industrial-Family looks for the roads with the purpose of centralizing the production and favoring the intermediate relations. These two modes of production reflect the human role in the change and creation of new land scapes from the pottery.

Effects of thinning intensities on soil infiltration and water storage capacity in a Chinese pine-oak mixed forest.

Science.gov (United States)

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning): soil infiltration rate and water storage capacity of pine-oak mixed forest in Qinling Mountains. The soil initial infiltration rate, stable infiltration rate, and average infiltration rate in thinning 30% treatment were significantly increased by 21.1%, 104.6%, and 60.9%, compared with the control. The soil maximal water storage capacity and noncapillary water storage capacity in thinning 30% treatment were significantly improved by 20.1% and 34.3% in contrast to the control. The soil infiltration rate and water storage capacity were significantly higher in the surface layer (0~20 cm) than in the deep layers (20~40 cm and 40~60 cm). We found that the soil property was closely related to soil infiltration rate and water storage capacity.

Thinning to improve growth, bole quality, and forest health in an Inonotus hispidus-infected, red oak-sweetgum stand in the Mississippi Delta: 10-year results

Science.gov (United States)

James S. Meadows; Theodor D. Leininger; David Montwé; T. Evan Nebeker

2013-01-01

A 55-year-old red oak-sweetgum (Quercus spp.- Liquidambar styraciflua) stand on the Delta National Forest in western Mississippi was subjected to a combination of low thinning and improvement cutting in 1997. Special emphasis was placed on removing all red oaks infected with Inonotus hispidus, a canker decay...

Seeding and planting upland oaks

Science.gov (United States)

1989-01-01

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

Behavioral assumptions of conservation policy: conserving oak habitat on family-forest land in the Willamette Valley, Oregon

Science.gov (United States)

A. Paige Fischer; John C. Bliss

2008-01-01

Designing policies that harness the motivations of landowners is essential for conserving threatened habitats on private lands. Our goal was to understand how to apply ethnographic information about family-forest owners to the design of conservation policy for Oregon white oak (Quercus garryana) in the Willamette Valley, Oregon (U.S.A.). We examined...

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

Czech Academy of Sciences Publication Activity Database

Vodka, Štěpán; Konvička, Martin; Čížek, Lukáš

2009-01-01

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

Impacts of prescribed fire on Pinus rigida Mill. in upland forests of the Atlantic Coastal Plain.

Science.gov (United States)

Carlo, Nicholas J; Renninger, Heidi J; Clark, Kenneth L; Schäfer, Karina V R

2016-08-01

A comparative analysis of the impacts of prescribed fire on three upland forest stands in the Northeastern Atlantic Plain, NJ, USA, was conducted. Effects of prescribed fire on water use and gas exchange of overstory pines were estimated via sap-flux rates and photosynthetic measurements on Pinus rigida Mill. Each study site had two sap-flux plots, one experiencing prescribed fire and one control (unburned) plot for comparison before and after the fire. We found that photosynthetic capacity in terms of Rubisco-limited carboxylation rate and intrinsic water-use efficiency was unaffected, while light compensation point and dark respiration rate were significantly lower in the burned vs control plots post-fire. Furthermore, quantum yield in pines in the pine-dominated stands was less affected than pines in the mixed oak/pine stand, as there was an increase in quantum yield in the oak/pine stand post-fire compared with the control (unburned) plot. We attribute this to an effect of forest type but not fire per se. Average daily sap-flux rates of the pine trees increased compared with control (unburned) plots in pine-dominated stands and decreased in the oak/pine stand compared with control (unburned) plots, potentially due to differences in fuel consumption and pre-fire sap-flux rates. Finally, when reference canopy stomatal conductance was analyzed, pines in the pine-dominated stands were more sensitive to changes in vapor pressure deficit (VPD), while stomatal responses of pines in the oak/pine stand were less affected by VPD. Therefore, prescribed fire affects physiological functioning and water use of pines, but the effects may be modulated by forest stand type and fuel consumption pattern, which suggests that these factors may need to be taken into account for forest management in fire-dominated systems. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

Science.gov (United States)

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

1999-01-01

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

Intraspecific variation in host susceptibility and climatic factors mediate epidemics of sudden oak death in western US forests

Science.gov (United States)

D. Huberli; K.J. Hayden; M. Calver; M. Garbelotto

2011-01-01

Umbellularia californica is one of the key infectious hosts of the exotic Phytophthora ramorum, which causes sudden oak death (SOD) in California and Oregon forests. This study provides a comprehensive analysis of the epidemiologically relevant parameters for SOD in California and southern Oregon, including potential differences between the two...

Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.

Science.gov (United States)

Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S

2016-09-01

We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality.

Domination Game: Extremal Families for the 3/5-Conjecture for Forests

Directory of Open Access Journals (Sweden)

Henning Michael A.

2017-05-01

Full Text Available In the domination game on a graph G, the players Dominator and Staller alternately select vertices of G. Each vertex chosen must strictly increase the number of vertices dominated. This process eventually produces a dominating set of G; Dominator aims to minimize the size of this set, while Staller aims to maximize it. The size of the dominating set produced under optimal play is the game domination number of G, denoted by γg(G. Kinnersley, West and Zamani [SIAM J. Discrete Math. 27 (2013 2090-2107] posted their 3/5-Conjecture that γg(G ≤ ⅗n for every isolate-free forest on n vertices. Brešar, Klavžar, Košmrlj and Rall [Discrete Appl. Math. 161 (2013 1308-1316] presented a construction that yields an infinite family of trees that attain the conjectured 3/5-bound. In this paper, we provide a much larger, but simpler, construction of extremal trees. We conjecture that if G is an isolate-free forest on n vertices satisfying γg(G = ⅗n, then every component of G belongs to our construction.

The Scandinavian Cooperative Advantage

DEFF Research Database (Denmark)

Strand, Robert; Freeman, R. Edward

In this article we clarify the historical roots of stakeholder theory to establish that a much larger role was played by Scandinavian thinkers in its development than is currently acknowledged. We show that important contributions to the stakeholder concept were being made by Eric Rhenman and his...... Scandinavian contemporaries in parallel to the contributions from the Stanford Research Institute (SRI) in the early 1960s and thereafter and thus are not a “historical trail” as they are currently labeled. Therefore we offer a significant modification to the historical narrative as presented in Strategic...... Management: A Stakeholder Approach (Freeman, 1984). These important Scandinavian contributions include the first publication and description of the expression „stakeholder‟ in management literature accessible to scholars throughout the world and the introduction of the first stakeholder map to the management...

Earthworms as indicators for different forest management types and human disturbance in Ilam oak forest, Iran

Directory of Open Access Journals (Sweden)

Heydari Mehdi

2014-09-01

Full Text Available There has been observed widespread destruction of natural ecosystems around the world due to population growth, land use change and clear cutting which have affected soil properties. Different management strategies have been so far implemented to reduce this crisis in various regions of the world, such as e.g. short-term and long-term conservation management in the Zagros region. However, any management approach should be evaluated with appropriate measures to determine how managed areas respond. The main objective of the present study was to evaluate the potential of earthworms as an indicator for different forest management strategies and human disturbances in Zagros oak (Quercus persica Jaub. and Spach forest. The sites selected included undisturbed one as the control (Un, the sites under five-year conservation management (FCM and twenty-year conservation management (TCM as well as the disturbed site (D. The results of principal component analysis (PCA showed that different regions separated into the components: PC1 and PC2. Un and TCM sites gathered together and represented higher values of the factors such as pH, Kavailable, OC, clay content, Pavailable, CEC, overstory tree canopy, Ntot, biomass and abundance of earthworms. The positive direction of the first axis reflected a gradient of EC, BD and Ptot. According to the logistic model, NH4-N and EC played the most important role in earthworm presence and absence in Zagros forest ecosystem. Earthworm abundance and biomass could be a good indicator to evaluate different forest management strategies in the study area.

Initial observations on tree mortality following a severe drought in 2012 in two Indiana state forests and implications for long-term compositional dynamics

Science.gov (United States)

Andrew R. Meier; Mike R. Saunders

2014-01-01

Compositional and structural changes in response to silvicultural treatments in forest stands are well documented (e.g., Saunders and Wagner 2008), but the stochastic nature of natural disturbance events often precludes direct observation of their impacts on stand dynamics. Though the current dominance of oak-hickory forest types in the Central Hardwoods Forest region...

Sudden oak death-caused changes to surface fuel loading and potential fire behavior in Douglas-fir-tanoak forests

Science.gov (United States)

Y.S. Valachovic; C.A. Lee; H. Scanlon; J.M. Varner; R. Glebocki; B.D. Graham; D.M. Rizzo

2011-01-01

We compared stand structure and fuel loading in northwestern California forests invaded by Phytophthora ramorum, the cause of sudden oak death, to assess whether the continued presence of this pathogen alters surface fuel loading and potential fire behavior in ways that may encumber future firefighting response. To attempt to account for these...

Photo guide for estimating fuel loading and fire behavior in mixed-oak forests of the Mid-Atlantic Region

Science.gov (United States)

Patrick H. Brose

2009-01-01

A field guide of 45 pairs of photographs depicting ericaceous shrub, leaf litter, and logging slash fuel types of eastern oak forests and observed fire behavior of these fuel types during prescribed burning. The guide contains instructions on how to use the photo guide to choose appropriate fuel models for prescribed fire planning.

Seasonal Pattern of Decomposition and N, P, and C Dynamics in Leaf litter in a Mongolian Oak Forest and a Korean Pine Plantation

Directory of Open Access Journals (Sweden)

Jaeeun Sohng

2014-10-01

Full Text Available Distinct seasons and diverse tree species characterize temperate deciduous forests in NE Asia, but large areas of deciduous forests have been converted to conifer plantations. This study was conducted to understand the effects of seasons and tree species on leaf litter decomposition in a temperate forest. Using the litterbag method, the decomposition rate and nitrogen, phosphorous, and carbon dynamics of Mongolian oak (Quercus mongolica, Korean pine (Pinus koraiensis, and their mixed leaf litter were compared for 24 months in a Mongolian oak stand, an adjacent Korean pine plantation, and a Mongolian oak—Korean pine mixed stand. The decomposition rates of all the leaf litter types followed a pattern of distinct seasonal changes: most leaf litter decomposition occurred during the summer. Tree species was less influential on the leaf litter decomposition. The decomposition rates among different leaf litter types within the same stand were not significantly different, indicating no mixed litter effect. The immobilization of leaf litter N and P lasted for 14 months. Mongolian oak leaf litter and Korean pine leaf litter showed different N and P contents and dynamics during the decomposition, and soil P2O5 was highest in the Korean pine plantation, suggesting effects of plantation on soil nutrient budget.

Mass loss and nutrient concentrations of buried wood as a function of organic matter removal, soil compaction, and vegetation control in a regenerating oak-pine forest

Science.gov (United States)

Felix Ponder; John M. Kabrick; Mary Beth Adams; Deborah S. Page-Dumroese; Marty F. Jurgensen

2017-01-01

Mass loss and nutrient concentrations of northern red oak (Quercus rubra) and white oak (Q. alba) wood stakes were measured 30 months after their burial in the upper 10 cm of soil in a regenerating forest after harvesting and soil disturbance. Disturbance treatments were two levels of organic matter (OM) removal (only...

Regenerating oaks with the shelterwood system

Science.gov (United States)

Ivan L. Sander

1979-01-01

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

Seed Bank Variation under Contrasting Site Quality Conditions in Mixed Oak Forests of Southeastern Ohio, USA

International Nuclear Information System (INIS)

Small, Ch.J.; McCarthy, B.C.

2010-01-01

Seed bank composition was sampled in 192-2.5 m 2 quadrats, established in six regenerating clearcut (∼7 years) and six second-growth ((∼125 years) mixed-oak forest stands in southeastern Ohio. Seed bank and aboveground composition diverged markedly (Sorensen's coefficient <10%), emphasizing the importance of fast-growing, early-successional germinants to early ecosystem recovery. Seed richness was significantly (ρ<.01) higher in clearcut stands, suggesting declining richness with stand age. Richness estimations 28%-60% higher than observed values demonstrated high seed bank heterogeneity, emphasizing the need for intensive sampling to assess temperate forest seed bank variation. Site quality (topographic aspect) strongly influenced seed bank composition, with greater importance of early-successional trees, thicket-forming shrubs, and nonnative species on mesic sites. Thus, forest seed banks are likely to play an important, site-dependent role in shaping competitive environments for commercially important timber species after harvesting and soil disturbance and have the potential for marked influence on post harvest forest development.

Examining fire-induced forest changes using novel remote sensing technique: a case study in a mixed pine-oak forest

Science.gov (United States)

Meng, R.; Wu, J.; Zhao, F. R.; Cook, B.; Hanavan, R. P.; Serbin, S.

2017-12-01

Fire-induced forest changes has long been a central focus for forest ecology and global carbon cycling studies, and is becoming a pressing issue for global change biologists particularly with the projected increases in the frequency and intensity of fire with a warmer and drier climate. Compared with time-consuming and labor intensive field-based approaches, remote sensing offers a promising way to efficiently assess fire effects and monitor post-fire forest responses across a range of spatial and temporal scales. However, traditional remote sensing studies relying on simple optical spectral indices or coarse resolution imagery still face a number of technical challenges, including confusion or contamination of the signal by understory dynamics and mixed pixels with moderate to coarse resolution data (>= 30 m). As such, traditional remote sensing may not meet the increasing demand for more ecologically-meaningful monitoring and quantitation of fire-induced forest changes. Here we examined the use of novel remote sensing technique (i.e. airborne imaging spectroscopy and LiDAR measurement, very high spatial resolution (VHR) space-borne multi-spectral measurement, and high temporal-spatial resolution UAS-based (Unmanned Aerial System) imagery), in combination with field and phenocam measurements to map forest burn severity across spatial scales, quantify crown-scale post-fire forest recovery rate, and track fire-induced phenology changes in the burned areas. We focused on a mixed pine-oak forest undergoing multiple fire disturbances for the past several years in Long Island, NY as a case study. We demonstrate that (1) forest burn severity mapping from VHR remote sensing measurement can capture crown-scale heterogeneous fire patterns over large-scale; (2) the combination of VHR optical and structural measurements provides an efficient means to remotely sense species-level post-fire forest responses; (3) the UAS-based remote sensing enables monitoring of fire

Ligninolytic Activity at 0 °C of Fungi on Oak Leaves Under Snow Cover in a Mixed Forest in Japan.

Science.gov (United States)

Miyamoto, Toshizumi; Koda, Keiichi; Kawaguchi, Arata; Uraki, Yasumitsu

2017-08-01

Despite the importance of litter decomposition under snow cover in boreal forests and tundra, very little is known regarding the characteristics and functions of litter-decomposing fungi adapted to the cold climate. We investigated the decomposition of oak leaves in a heavy snowfall forest region of Japan. The rate of litter weight loss reached 26.5% during the snow cover period for 7 months and accounted for 64.6% of the annual loss (41.1%). Although no statistically significant lignin loss was detected, decolourization portions of oak leaf litter, which was attributable to the activities of ligninolytic fungi, were observed during snow cover period. This suggests that fungi involved in litter decomposition can produce extracellular enzymes to degrade lignin that remain active at 0 °C. Fungi were isolated from oak leaves collected from the forest floor under the snow layer. One hundred and sixty-six strains were isolated and classified into 33 operational taxonomic units (OTUs) based on culture characteristics and nuclear rDNA internal transcribed spacer (ITS) region sequences. To test the ability to degrade lignin, the production of extracellular phenoloxidases by isolates was quantified at 0 °C. Ten OTUs (9 Ascomycota and 1 Basidiomycota) of fungi exhibited mycelial growth and ligninolytic activity. These results suggested that some litter-decomposing fungi that had the potential to degrade lignin at 0 °C significantly contribute to litter decomposition under snow cover.

Energy and cooperation among the Scandinavian countries

Energy Technology Data Exchange (ETDEWEB)

Milas, R

1984-11-01

The Scandinavian countries have a long experience of functional cooperation in the field of energy. The oil crisis has been largely attenuated for Norway since the exploitation of the North Sea oil deposits. The future will be oil or nuclear, this is the characteristic of energy cooperation on the Scandinavian, European and international levels. In this connection, no level excludes another and the Scandinavian countries are going to patiently attempt to benefit from their Scandinavian dimension over the short range, their European vocation for research and development and their free trade ideology for the surveillance of markets on the level of international agencies.

The Routledge Handbook of Scandinavian Politics

DEFF Research Database (Denmark)

Scandinavian politics today through a series of cutting-edge chapters. It will be a key reference point both for advanced-level students developing knowledge about the subject, as well as researchers producing new material in the area and beyond. It brings geographical scope and depth, with comparative...... chapters contributed by experts across the region. Methodologically and theoretically pluralistic, the handbook is in itself a reflection of the field of political science in Scandinavia and the diversity of the issues covered in the volume. The Routledge Handbook of Scandinavian Politics......The Routledge Handbook of Scandinavian Politics is a comprehensive overview of Scandinavian politics provided by leading experts in the field and covering the polity, the politics and the policy of Scandinavia. Coherently structured with a multi-level thematic approach, it explains and details...

Do Scandinavian Care about international law?

DEFF Research Database (Denmark)

Wind, Marlene

2016-01-01

Although Scandinavians are often celebrated as the vanguards of human rights and international law, we know little about whether courts and judges in these countries have embraced those international courts and conventions that they themselves helped establish after the Second World War....... This article presents original and comprehensive data on three Scandinavian courts' citation practice. It demonstrates that not only do Scandinavian Supreme Courts engage surprisingly little with international law, but also that there is great variation in the degree to which they have domesticated...... international law and courts by citing their case law. Building on this author's previous research, it is argued that Norway sticks out as much more engaged internationally due to a solid judicial review tradition at the national level. It is also argued that Scandinavian legal positivism has influenced a much...

Seed production differences of the Andean oak Quercus Humboldtii Bonpl. in two Andean forests of the Colombian Eastern Cordillera

International Nuclear Information System (INIS)

Gonzalez Melo, Andres; Parrado Rosselli Angela

2010-01-01

Knowledge of mechanisms of tree species reproduction under natural situations including fruit and seed production patterns is very important for forest management strategies. Considering the influence of abiotic factors such as soil characteristics, humidity and rainfall on fruiting phenology, we studied fruit production patterns of the Andean oak (Quercus humboldtii: Fagaceae) in two forest sites of the Colombian Eastern Cordillera (Cachalu and Patios Altos), under contrasting environmental conditions. At both sites, we monitored monthly fruit production of 15 trees in Cachalu and 11 in Patios Altos using fruit/seed traps placed under the tree crowns. In each site soil cores were extracted below the litter layer 20 cm depth, and soil characteristics and nutrients were analyzed. In general, trees in Cachalu produced more fruits than in Patios Altos, as well as mean fruit mass (wet and dry weight) was significantly higher in Cachalu. At both sites, oak fruiting peaked from April to May, when the highest rainfall occurs. We found positive correlations between fruit production and rainfall one month prior. High phosphorus (P) and potassium (K) were the main variables for explaining the high production. In contrast, high aluminum (Al) contents explained the low production found in Patios Altos. We discuss the importance of including fruit production for oak management strategies, such as restoration and reforestation programs.

Influence of climate and land use on historical surface fires in pine-oak forests, Sierra Madre Occidental, Mexico

Science.gov (United States)

Emily K. Heyerdahl; Ernesto Alvarado

2003-01-01

The rugged mountains of the Sierra Madre Occidental, in north-central Mexico, support a mosaic of diverse ecosystems. Of these, the high-elevation, temperate pine-oak forests are ecologically significant for their extensiveness and biodiversity. They cover nearly half the land area in the states of Durango and Chihuahua (42%), and comprise a similar percentage of the...

The Scandinavian Cooperative Advantage

OpenAIRE

Strand, Robert; Freeman, R. Edward

2013-01-01

In this article we clarify the historical roots of stakeholder theory to establish that a much larger role was played by Scandinavian thinkers in its development than is currently acknowledged. We show that important contributions to the stakeholder concept were being made by Eric Rhenman and his Scandinavian contemporaries in parallel to the contributions from the Stanford Research Institute (SRI) in the early 1960s and thereafter and thus are not a “historical trail” as they ...

Plant and bird diversity in natural forests and in native and exotic plantations in NW Portugal

Science.gov (United States)

Proença, Vânia M.; Pereira, Henrique M.; Guilherme, João; Vicente, Luís

2010-03-01

Forest ecosystems have been subjected to continuous dynamics between deforestation and forestation. Assessing the effects of these processes on biodiversity could be essential for conservation planning. We analyzed patterns of species richness, diversity and evenness of plants and birds in patches of natural forest of Quercus spp. and in stands of native Pinus pinaster and exotic Eucalyptus globulus in NW Portugal. We analyzed data of forest and non-forest species separately, at the intra-patch, patch and inter-patch scales. Forest plant richness, diversity and evenness were higher in oak forest than in pine and eucalypt plantations. In total, 52 species of forest plants were observed in oak forest, 33 in pine plantation and 28 in eucalypt plantation. Some forest species, such as Euphorbia dulcis, Omphalodes nitida and Eryngium juresianum, were exclusively or mostly observed in oak forest. Forest bird richness and diversity were higher in both oak and pine forests than in eucalypt forest; evenness did not differ among forests. In total, 16 species of forest birds were observed in oak forest, 18 in pine forest and 11 in eucalypt forest. Species such as Certhia brachydactyla, Sitta europaea and Dendrocopos major were common in oak and/or pine patches but were absent from eucalypt stands. Species-area relationships of forest plants and forest birds in oak patches had consistently a higher slope, at both the intra and inter-patch scales, than species-area relationships of forest species in plantations and non-forest species in oak forest. These findings demonstrate the importance of oak forest for the conservation of forest species diversity, pointing the need to conserve large areas of oak forest due to the apparent vulnerability of forest species to area loss. Additionally, diversity patterns in pine forest were intermediate between oak forest and eucalypt forest, suggesting that forest species patterns may be affected by forest naturalness.

Phytophthora ramorum detection surveys for forests in the United States

Science.gov (United States)

S. W. Oak; W. D. Smith; B.M. Tkacz

2006-01-01

Diseases caused by Phytophthora ramorum in forest landscapes of North America are presently confined to areas of the Pacific coast in the states of CA and OR. However, the vulnerability of other ecosystems is suggested by the discovery in Europe and the U.K. of disease in hosts which are abundant in oak-dominated ecosystems of eastern North America;...

Oak conservation and restoration on private forestlands: negotiating a social-ecological landscape.

Science.gov (United States)

Knoot, Tricia G; Schulte, Lisa A; Rickenbach, Mark

2010-01-01

In the midwestern United States, oak (Quercus spp.) forests are considered critical habitat for conserving biodiversity and are a declining resource. Ecological conditions, such as deer herbivory and competition from more mesic broad-leaved deciduous species, have been linked to poor oak regeneration. In the Midwest, where up to 90% of forestland is privately owned, a greater understanding of social dimensions of oak regeneration success is especially critical to designing effective restoration strategies. We sought to determine factors that serve as direct and indirect constraints to oak restoration and identify policy mechanisms that could improve the likelihood for restoration success. We conducted in-depth qualitative interviews with 32 natural resource professionals working in the Midwest Driftless Area. We found that most professionals anticipate that oak will remain only a component of the future forest. Furthermore, they identified the general unwillingness of landowners to adopt oak restoration practices as a primary driving force of regional forest change. The professionals pointed to interdependent ecological and social factors, occurring at various scales (e.g., economic cost of management, deer herbivory, and exurban residential development) as influencing landowner oak restoration decisions. Professionals emphasized the importance of government cost-share programs and long-term personal relationships to securing landowner acceptance of oak restoration practices. However, given finite societal resources, ecologically- and socially-targeted approaches were viewed as potential ways to optimize regional success.

Dominant effect of increasing forest biomass on evapotranspiration: interpretations of movement in Budyko space

Science.gov (United States)

Jaramillo, Fernando; Cory, Neil; Arheimer, Berit; Laudon, Hjalmar; van der Velde, Ype; Hasper, Thomas B.; Teutschbein, Claudia; Uddling, Johan

2018-01-01

During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s) of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961-2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60 % of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large-scale evapotranspiration

The epidemiology of sudden oak death in Oregon forests

Science.gov (United States)

Ebba K. Peterson

2011-01-01

The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus...

Elemental concentrations in foliage of red maple, red oak, and white oak in relation to atmospheric deposition in Pennsylvania

Science.gov (United States)

D. D. Davis; J. M. Skelly; B. L. Nash

1995-01-01

Foliage was sampled in June and late August-early September in 1988 and 1989 from the outer crowns of codominant red maple (Acer rubrum L.), northern red oak (Quercus rubra L.), and white oak (Q. alba L.) trees in forest stands along an atmospheric deposition gradient in north-central Pennsylvania. Leaf samples...

Management of oak forests

DEFF Research Database (Denmark)

Löf, Magnus; Brunet, Jörg; Filyushkina, Anna

2016-01-01

timber production, habitats for biodiversity and cultural services, and the study analyses associated trade-offs and synergies. The three regimes were: intensive oak timber production (A), combined management for both timber production and biodiversity (B) and biodiversity conservation without management...... of wood production and cultural services. In contrast, Regime B provided a balanced delivery of timber production, biodiversity conservation and cultural services. We identified several stand-management options which provide comparatively synergistic outcomes in ecosystem services delivery. The use...

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....

Long-term variability in the water budget and its controls in an oak-dominated temperate forest

Science.gov (United States)

Jing Xie; Ge Sun; Hou-Sen Chu; Junguo Liu; Steven G. McNulty; Asko Noormets; Ranjeet John; Zutao Ouyang; Tianshan Zha; Haitao Li; Wenbin Guan; Jiquan Chen

2014-01-01

Water availability is one of the key environmental factors that control ecosystem functions in temperate forests. Changing climate is likely to alter the ecohydrology and other ecosystem processes, which affect forest structures and functions. We constructed a multi-year water budget (2004–2010) and quantified environmental controls on an evapotranspiration (ET) in a...

Carbon Stocks of Fine Woody Debris in Coppice Oak Forests at Different Development Stages

Directory of Open Access Journals (Sweden)

Ender Makineci

2017-06-01

Full Text Available Dead woody debris is a significant component of the carbon cycle in forest ecosystems. This study was conducted in coppice-originated oak forests to determine carbon stocks of dead woody debris in addition to carbon stocks of different ecosystem compartments from the same area and forests which were formerly elucidated. Weight and carbon stocks of woody debris were determined with recent samplings and compared among development stages (diameter at breast height (DBH, D1.3m, namely small-diameter forests (SDF = 0–8 cm, medium diameter forests (MDF = 8–20 cm, and large-diameter forests (LDF = 20–36 cm. Total woody debris was collected in samplings; as bilateral diameters of all woody debris parts were less than 10 cm, all woody parts were in the “fine woody debris (FWD” class. The carbon concentrations of FWD were about 48% for all stages. Mass (0.78–4.92 Mg·ha−1 and carbon stocks (0.38–2.39 Mg·ha−1 of FWD were significantly (p > 0.05 different among development stages. FWD carbon stocks were observed to have significant correlation with D1.3m, age, basal area, and carbon stocks of aboveground biomass (Spearman rank correlation coefficients; 0.757, 0.735, 0.709, and 0.694, respectively. The most important effects on carbon budgets of fine woody debris were determined to be coppice management and intensive utilization. Also, national forestry management, treatments of traditional former coppice, and conversion to high forest were emphasized as having substantial effects.

Characterization of total ecosystem scale biogenic VOC exchange at a Mediterranean oak-hornbeam forest

Science.gov (United States)

Schallhart, S.; Rantala, P.; Nemitz, E.; Mogensen, D.; Tillmann, R.; Mentel, T. F.; Rinne, J.; Ruuskanen, T. M.

2015-10-01

Recently, the number and amount of biogenically emitted volatile organic compounds (VOCs) has been discussed vigorously. Depending on the ecosystem the published number varies between a dozen and several hundred compounds. We present ecosystem exchange fluxes from a mixed oak-hornbeam forest in the Po Valley, Italy. The fluxes were measured by a proton transfer reaction-time-of-flight (PTR-ToF) mass spectrometer and calculated by the eddy covariance (EC) method. Detectable fluxes were observed for twelve compounds, dominated by isoprene, which comprised over 65 % of the total flux emission. The daily average of the total VOC emission was 9.5 nmol m-2 s-1. Methanol had the highest concentration and accounted for the largest deposition. Methanol seemed to be deposited to dew, as the deposition happened in the early morning, right after the calculated surface temperature came closest to the calculated dew point temperature. We estimated that up to 27 % of the upward flux of methyl vinyl ketone (MVK) and methacrolein (MACR) originated from atmospheric oxidation of isoprene. A comparison between two flux detection methods (classical/visual and automated) was made. Their respective advantages and disadvantages were discussed and the differences in their results shown. Both provide comparable results; however we recommend the automated method with a compound filter, which combines the fast analysis and better flux detection, without the overestimation due to double counting.

Avian response to fire in pine–oak forests of Great Smoky Mountains National Park following decades of fire suppression

Science.gov (United States)

Rose, Eli T.; Simons, Theodore R.

2016-01-01

Fire suppression in southern Appalachian pine–oak forests during the past century dramatically altered the bird community. Fire return intervals decreased, resulting in local extirpation or population declines of many bird species adapted to post-fire plant communities. Within Great Smoky Mountains National Park, declines have been strongest for birds inhabiting xeric pine–oak forests that depend on frequent fire. The buildup of fuels after decades of fire suppression led to changes in the 1996 Great Smoky Mountains Fire Management Plan. Although fire return intervals remain well below historic levels, management changes have helped increase the amount of fire within the park over the past 20 years, providing an opportunity to study patterns of fire severity, time since burn, and bird occurrence. We combined avian point counts in burned and unburned areas with remote sensing indices of fire severity to infer temporal changes in bird occurrence for up to 28 years following fire. Using hierarchical linear models that account for the possibility of a species presence at a site when no individuals are detected, we developed occurrence models for 24 species: 13 occurred more frequently in burned areas, 2 occurred less frequently, and 9 showed no significant difference between burned and unburned areas. Within burned areas, the top models for each species included fire severity, time since burn, or both, suggesting that fire influenced patterns of species occurrence for all 24 species. Our findings suggest that no single fire management strategy will suit all species. To capture peak occupancy for the entire bird community within xeric pine–oak forests, at least 3 fire regimes may be necessary; one applying frequent low severity fire, another using infrequent low severity fire, and a third using infrequently applied high severity fire.

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...

Seed Bank Variation under Contrasting Site Quality Conditions in Mixed Oak Forests of Southeastern Ohio, USA

Directory of Open Access Journals (Sweden)

Christine J. Small

2010-01-01

Full Text Available Seed bank composition was sampled in 192–2.5 m2 quadrats, established in six regenerating clearcut (∼7 years and six second-growth (∼125 years mixed-oak forest stands in southeastern Ohio. Seed bank and aboveground composition diverged markedly (Sørensen's coefficient <10%, emphasizing the importance of fast-growing, early-successional germinants to early ecosystem recovery. Seed richness was significantly (P<.01 higher in clearcut stands, suggesting declining richness with stand age. Richness estimations 28%–60% higher than observed values demonstrated high seed bank heterogeneity, emphasizing the need for intensive sampling to assess temperate forest seed bank variation. Site quality (topographic aspect strongly influenced seed bank composition, with greater importance of early-successional trees, thicket-forming shrubs, and nonnative species on mesic sites. Thus, forest seed banks are likely to play an important, site-dependent role in shaping competitive environments for commercially important timber species after harvesting and soil disturbance and have the potential for marked influence on postharvest forest development.

Some natural factors that govern the management of oaks

Science.gov (United States)

Sidney Weitzman; G. R., Jr. Trimble

1957-01-01

The oaks are the most important species group in the Appalachian hardwood forests. In West Virginia, oaks provide more than half of the lumber produced in the State. In addition, they provide a large portion of the mine timbers and specialty products.

Projected changes in the future distribution and production of sessile oak forests near the xeric limit

Science.gov (United States)

Gulyás, Krisztina; Berki, Imre; Veperdi, Gábor

2017-04-01

As a result of regional climate change, most European countries are experiencing an increase in mean annual temperature and CO2 concentration and a decrease in mean annual precipitation. In low-elevation areas in Southeast Europe, where precipitation is a limiting factor, the projected climate change threatens the health, production, and potential distribution of forest ecosystems. The intensive summer droughts and commonly occurring extreme weather events create negative influences that cause health declines, changes in yield potential, and tree mortality. Due to the observed damages, attention has been focused on these problems. The impacts of climatic extremes cause difficulties in forest management; these difficulties occur more frequently in Hungary, which is a region that is the most sensitive to climatic extremes. Regional climate model simulations project that the frequency of extremely high temperatures and long-term dry periods will increase; both of these factors have negative effects on future tree species distribution and production. Thus, the aim of our study is to utilize the sessile oak (Quercus petraea) as a climate indicator tree species to investigate potential future distribution and estimate changes in growth trends. For future spatial distribution, we used the Fuzzy membership distribution model in a new Decision Support System (DSS) which was developed for the Hungarian forestry and agricultural sectors. Through study techniques we can employ DSS, which contains various environmental layers (topography, vegetation, past and projected future climate, soils, and hydrology), to create probability distribution maps. The results, based on 12 regional climate model simulations (www.ensembles-eu.org), show that the area of sessile oak forests is shrinking continuously and will continue to do so to the end of the 21st century. For future production estimations, we analysed intensive long-term growth monitoring network plots that were established in

Utilization of the invasive plant Impatiens parviflora DC. by the snail Columella edentula Draparnaud in oak-hornbeam forests

Directory of Open Access Journals (Sweden)

Renata Piskorz

2011-01-01

Full Text Available This study investigated the extend to which the snail Columella edentula is more strongly associated with the small balsam Impatiens parviflora than with other plants in the herb layer of an oak-hornbeam forest, and to interpret the character of the interaction Impatiens parviflora - Columella edentula. Numbers of C. edentula and rates of colonization were compared on various plant species under natural and laboratory conditions. Seasonal variation in snail abundance on I. parviflora was observed on permanent plots. The leaf injuries caused by C. edentula were localized in respect of the morphological and anatomical structure of leaves. The results show that I. parviflora is one of the plant species of the herb layer that are most abundantly colonized by this snail in oak-hornbeam forest. Snail finds a plant particularly suitable as a place for resting. The most favoured attachment site is on the underside of the leaf, along the midrib, which provides the highest and relatively stable humidity, as well as protection from direct sunlight and predators. I. parviflora is also a food for the snails, but they do not eat these fragments of leaves where calcium carbonate is accumulated.

Distributional record of oak gall wasp (Hymenoptera: Cynipidae ...

African Journals Online (AJOL)

In this survey, oak gall wasp species were collected from the oak forests of Pardanan, Mirabad, Nalas, Sardasht, Hamran and Dar-ghabr in West-Azerbaijan province. The galls occurring on 50 cm sampled branches from four cardinal directions on each tree were counted multiple times throughout the season. Species ...

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

Science.gov (United States)

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

2013-09-01

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

Dominant effect of increasing forest biomass on evapotranspiration: interpretations of movement in Budyko space

Directory of Open Access Journals (Sweden)

F. Jaramillo

2018-01-01

Full Text Available During the last 6 decades, forest biomass has increased in Sweden mainly due to forest management, with a possible increasing effect on evapotranspiration. However, increasing global CO2 concentrations may also trigger physiological water-saving responses in broadleaf tree species, and to a lesser degree in some needleleaf conifer species, inducing an opposite effect. Additionally, changes in other forest attributes may also affect evapotranspiration. In this study, we aimed to detect the dominating effect(s of forest change on evapotranspiration by studying changes in the ratio of actual evapotranspiration to precipitation, known as the evaporative ratio, during the period 1961–2012. We first used the Budyko framework of water and energy availability at the basin scale to study the hydroclimatic movements in Budyko space of 65 temperate and boreal basins during this period. We found that movements in Budyko space could not be explained by climatic changes in precipitation and potential evapotranspiration in 60 % of these basins, suggesting the existence of other dominant drivers of hydroclimatic change. In both the temperate and boreal basin groups studied, a negative climatic effect on the evaporative ratio was counteracted by a positive residual effect. The positive residual effect occurred along with increasing standing forest biomass in the temperate and boreal basin groups, increasing forest cover in the temperate basin group and no apparent changes in forest species composition in any group. From the three forest attributes, standing forest biomass was the one that could explain most of the variance of the residual effect in both basin groups. These results further suggest that the water-saving response to increasing CO2 in these forests is either negligible or overridden by the opposite effect of the increasing forest biomass. Thus, we conclude that increasing standing forest biomass is the dominant driver of long-term and large

Short-term response of small mammals following oak regeneration silviculture treatments.

Science.gov (United States)

Amy L. Raybuck; Christopher E. Moorman; Christopher S. DePerno; Kevin Gross; Dean M. Simon; Gordon S. Warburton

2012-01-01

Upland, mixed-oak forests in the eastern United States have experienced widespread oak regeneration failure, largely due to cessation of anthropogenic disturbance. Silvicultural practices used to promote advance oak regeneration may affect ground-dwelling mammals. From May to August 2008 (pre-treatment), 2010 (first year post-treatment), and 2011 (second year post-...

Epiphytic lichen diversity in central European oak forests: Assessment of the effects of natural environmental factors and human influences

International Nuclear Information System (INIS)

Svoboda, David; Peksa, Ondrej; Vesela, Jana

2010-01-01

We investigated lichen diversity in temperate oak forests using standardized protocols. Forty-eight sites were sampled in the Czech Republic, Slovakia and Hungary. The effects of natural environmental predictors and human influences on lichen diversity (lichen diversity value, species richness) were analysed by means of correlation tests. We found that lichen diversity responded differently to environmental predictors between two regions with different human impact. In the industrial region, air pollution was the strongest factor. In the agricultural to highly forested regions, lichen diversity was strongly influenced by forest age and forest fragmentation. We found that several natural factors can in some cases obscure the effect of human influences. Thus, factors of naturality gradient must be considered (both statistically and interpretively) when studying human impact on lichen diversity. - We detected the different responses of lichens to ecological predictors in polluted and unpolluted areas.

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

Science.gov (United States)

William F. Jr. Laudenslayer; Roberta J. Fargo

2002-01-01

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

Occurrence of Phytophthora plurivora and other Phytophthora species in oak forests of southern Poland and their association with site conditions and the health status of trees.

Science.gov (United States)

Jankowiak, R; Stępniewska, H; Bilański, P; Kolařík, M

2014-11-01

Phytophthora plurivora and other Phytophthora species are known to be serious pathogens of forest trees. Little is known, however, about the presence of P. plurivora in Polish oak forests and their role in oak decline. The aims of this study were to identify P. plurivora in healthy and declining Quercus robur stands in southern Poland and to demonstrate the relationship between different site factors and the occurrence of P. plurivora. In addition, the virulence of P. plurivora and other Phytophthora species was evaluated through inoculations using 2-year-old oak seedlings. Rhizosphere soil was investigated from 39 oak stands representing different healthy tree statuses. The morphology and DNA sequences of the internal transcribed spacer regions (ITS) of the ribosomal DNA and the mitochondrial cox1 gene were used for identifications. P. plurivora, an oak fine root pathogen, was isolated from rhizosphere soil samples in 6 out of 39 stands. Additionally, Phytophthora cambivora, Phytophthora polonica and Phytophthora rosacearum-like were also obtained from several stands. The results showed a significant association between the presence of P. plurivora and the health status of oak trees. Similar relationships were also observed for all identified Phytophthora species. In addition, there was evidence for a connection between the presence of all identified Phytophthora species and some site conditions. Phytophthora spp. occurred more frequently in declining stands and in silt loam and sandy loam soils with pH ≥ 3.66. P. plurivora and P. cambivora were the only species capable of killing whole plants, producing extensive necrosis on seedling stems.

Archival Education in Scandinavian Countries

Directory of Open Access Journals (Sweden)

Muhammet Hanefi Kutluoğlu

2008-03-01

Full Text Available Every country has responsibilities to provide the necessary personnel needed for their archival inheritance by education. Education can be shaped through tradition, historical inheritance and scientifi c necessities by defi ning the right educational method. Scandinavian countries have determined different education models based on their tradition, historical inheritance and requirements. In this article we focused on the formation of archival tradition, application of archival education in Scandinavian countries and the infl uence of the developments taking place in Europe on these countries. The relation between the archival education in European and Scandinavian countries is evaluated through a comparative method, and similarities to other countries are also evaluated. Finally, the present situation of archival education and the measures needed in this fi eld are taken into consideration.

Status and conservation of old-growth forests and endemic birds in the pine-oak zone of the Sierra Madre Occidental, Mexico

NARCIS (Netherlands)

Lammertink, J.M.; Rojas-Tomé, J.A.; Casillas-Orona, F.M.; Otto, R.L.

1996-01-01

The pine-oak forests of the Sierra Madre Occidental, a mountain range in NW Mexico, have recently been recognized as an area of high endemism and biodiversity. Selective logging threatens three bird species endemic to this habitat, who depend on standing dead trees (snags). This report is based on

Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae) dominated tropical rain forest (Talamanca, Costa Rica).

Science.gov (United States)

Valverde-Barrantes, Oscar J; Rocha, Oscar J

2014-03-01

The factors that determine the existence of tropical forests dominated by a single species (monodominated forests) have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees > or = 2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02) and 12 years (L-12) prior to sampling and an unlogged forest (ULF). Our results showed that L-02 stands had lower species richness (25 species) than the L-12 and ULF stands (49 and 46 species, respectively). As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/ m2) than in the L-02 and L-12 stands (0.322 and 0.466 seedlings/m2, respectively). However, seedling mortality was higher in the ULF stands (54%) than in the L-02 (26%) and L-12 (15%) stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions.

Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae dominated tropical rain forest (Talamanca, Costa Rica

Directory of Open Access Journals (Sweden)

Oscar J. Valverde-Barrantes

2014-03-01

Full Text Available The factors that determine the existence of tropical forests dominated by a single species (monodominated forests have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees ≥2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02 and 12 years (L-12 prior to sampling and an unlogged forest (ULF. Our results showed that L-02 stands had lower species richness (25 species than the L-12 and ULF stands (49 and 46 species, respectively. As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/m² than in the L-02and L-12 stands (0.322 and 0.466 seedlings/m², respectively. However, seedling mortality was higher in the ULF stands (54% than in the L-02 (26% and L-12 (15% stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions. Rev. Biol. Trop. 62 (1: 347-357. Epub 2014 March 01.

Ability of LANDSAT-8 Oli Derived Texture Metrics in Estimating Aboveground Carbon Stocks of Coppice Oak Forests

Science.gov (United States)

Safari, A.; Sohrabi, H.

2016-06-01

The role of forests as a reservoir for carbon has prompted the need for timely and reliable estimation of aboveground carbon stocks. Since measurement of aboveground carbon stocks of forests is a destructive, costly and time-consuming activity, aerial and satellite remote sensing techniques have gained many attentions in this field. Despite the fact that using aerial data for predicting aboveground carbon stocks has been proved as a highly accurate method, there are challenges related to high acquisition costs, small area coverage, and limited availability of these data. These challenges are more critical for non-commercial forests located in low-income countries. Landsat program provides repetitive acquisition of high-resolution multispectral data, which are freely available. The aim of this study was to assess the potential of multispectral Landsat 8 Operational Land Imager (OLI) derived texture metrics in quantifying aboveground carbon stocks of coppice Oak forests in Zagros Mountains, Iran. We used four different window sizes (3×3, 5×5, 7×7, and 9×9), and four different offsets ([0,1], [1,1], [1,0], and [1,-1]) to derive nine texture metrics (angular second moment, contrast, correlation, dissimilar, entropy, homogeneity, inverse difference, mean, and variance) from four bands (blue, green, red, and infrared). Totally, 124 sample plots in two different forests were measured and carbon was calculated using species-specific allometric models. Stepwise regression analysis was applied to estimate biomass from derived metrics. Results showed that, in general, larger size of window for deriving texture metrics resulted models with better fitting parameters. In addition, the correlation of the spectral bands for deriving texture metrics in regression models was ranked as b4>b3>b2>b5. The best offset was [1,-1]. Amongst the different metrics, mean and entropy were entered in most of the regression models. Overall, different models based on derived texture metrics

Conservation biogeography of red oaks (Quercus, section Lobatae) in Mexico and Central America.

Science.gov (United States)

Torres-Miranda, Andrés; Luna-Vega, Isolda; Oyama, Ken

2011-02-01

Oaks are dominant trees and key species in many temperate and subtropical forests in the world. In this study, we analyzed patterns of distribution of red oaks (Quercus, section Lobatae) occurring in Mexico and Central America to determine areas of species richness and endemism to propose areas of conservation. Patterns of richness and endemism of 75 red oak species were analyzed using three different units. Two complementarity algorithms based on species richness and three algorithms based on species rarity were used to identify important areas for conservation. A simulated annealing analysis was performed to evaluate and formulate effective new reserves for red oaks that are useful for conserving the ecosystems associated with them after the systematic conservation planning approach. Two main centers of species richness were detected. The northern Sierra Madre Oriental and Serranías Meridionales of Jalisco had the highest values of endemism. Fourteen areas were considered as priorities for conservation of red oak species based on the 26 priority political entities, 11 floristic units and the priority grid-cells obtained in the complementarity analysis. In the present network of Natural Protected Areas in Mexico and Central America, only 41.3% (31 species) of the red oak species are protected. The simulated annealing analysis indicated that to protect all 75 species of red oaks, 12 current natural protected areas need to be expanded by 120000 ha of additional land, and 26 new natural protected areas with 512500 ha need to be created. Red oaks are a useful model to identify areas for conservation based on species richness and endemism as a result of their wide geographic distribution and a high number of species. We evaluated and reformulated new reserves for red oaks that are also useful for the conservation of ecosystems associated with them.

Scandinavian links

DEFF Research Database (Denmark)

Matthiessen, Christian Wichmann; Knowles, Richard D.

2014-01-01

are impressive mega structures spanning international waterways. These waterways between the Baltic Sea and the North Sea have played major roles in history. The length of each of the crossings are around 20 km. The fixed links closes gaps between the Scandinavian and European motorway and rail networks...

Randomised controlled trials in Scandinavian educational research

DEFF Research Database (Denmark)

Pontoppidan, Maiken; Keilow, Maria; Dietrichson, Jens

2018-01-01

of this paper is to examine the history of randomised controlled trials in Scandinavian compulsory schools (grades 0–10; pupil ages 6-15). Specifically, we investigate drivers and barriers for randomised controlled trials in educational research and the differences between the three Scandinavian countries...... crucial for the implementation of RCTs and are likely more important in smaller countries such as the Scandinavian ones. Supporting institutions have now been established in all three countries, and we believe that the use of RCTs in Scandinavian educational research is likely to continue....... or more interventions were randomly assigned to groups of students and carried out in a school setting with the primary aim of improving the academic performance of children aged 6-15 in grades 0–10 in Denmark, Norway, or Sweden. We included both conducted and ongoing trials. Publications that seemed...

Dynamics of forest populations in the mountain resort region of the North Caucasus

Science.gov (United States)

Chalaya, Elena; Efimenko, Natalia; Slepykh, Olga; Slepykh, Viktor; Povolotskaya, Nina

2017-04-01

Prehistoric formula of forest species composition of the resort region Caucasian Mineralnye Vody (RR CMV) in the North Caucasus is 6Q3Cb1Fe [1]. According to it, undisturbed forests of the region consisted of the pedunculate oak (Quercus robur L.) and the durmast (Quercus cerris L.) by 60%, the European hornbeam (Carpinus betulus L.) by 30% and the European ash (Fraxinus excelsior L.) only by 10%. At present the formula of forest composition of the region is 5Fe3Cb2Q, according to it, the rate of oak-groves (the most valuable to resort landscape gardening) has reduced to 20%, and the ash-tree, though the rate of the hornbeam has not changed, increased up to 50%. Forest breeding populations in the RR CMV are referred to natural medical resources as they have high rehabilitation and climate-regulating properties, the change in forest breeding populations influences the conditions of the resort climate-landscape-therapy. The researches conducted in the perfect oak wood of vegetative origin in Beshtaugorsky Forestry Area (BFA) of the RR CMV have shown the reduction of the pedunculate oak in the tree-stand composition during 1984-2014 from 10 to 8 units in the composition: the European ash (1 unit) and the crataegus monogyna (Crataegus monogyna Jacq.), the checker tree (Sorbus torminalis (L.) Crantz), the common pear (Pyrus communis L.) have appeared [2]. The rate of the pedunculate oak decreased from 10 units to 9 in the perfect planting of the pedunculate oak of the artificial origin (Mashuk section of the forestry of BFA of the RR CMV) during 1986-2016. Among accompanying breeds there was the English field maple (Acer campestre L.), the Chinese elm in singular (Ulmus parvifolia Jacq.), the single-seed hawthorn. The reliable regrowth (4C3Fe3Ac+Q+Cm+Pc+Up) in number of 3,9 thousand pieces/hectare defines the perspective of complete replacement of the oak crop in the future on planting with dominance of the hornbeam and the involvement of the ash-tree and the English

Properties of Hungarian oak(quercus conferta Kit. wood from the Hilandar Monastery forest

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Popović Zdravko

2007-01-01

Full Text Available This paper presents the study results of the basic physical and strength properties of Hungarian oak (Quercus conferta Kit. wood from the Kakovo Monastery forests of Hilandar Monastery in Greece. Wood properties were analyzed in detail, as an indispensable proof of wood quality and its use for joinery, interiors and wooden floors. The basic physical properties of wood (moisture content at the time of tree felling, density and volume porosity and the basic strength properties (compressive strength, bending strength and module of elasticity were researched. The results are presented in Tables and in Diagrams with statistical parameters and compared to the literature data. The correlation of the study properties of wood was also analyzed.

Status and conservation of old-growth forests and endemic birds in the pine-oak zone of the Sierra Madre occidental Mexico

OpenAIRE

Lammertink, J.M.; Rojas-Tome, J.A.; Casillas-Orona, F.M.; Otto, R.L.

1996-01-01

The pine-oak forests of the Sierra Madre Occidental, a mountain range in NW Mexico, have recently been recognized as an area of high endemism and biodiversity. Selective logging threatens three bird species endemic to this habitat, who depend on standing dead trees (snags). This report is based on an 11 month field survey that aimed to locate oldgrowth remnants and to assess the status of the endemic birds. Old-growth is defined here as a forest that has never been logged mechanically. Old-gr...

Floristic diversity of posavina's floodplain forests in serbia and their wider geographical context

International Nuclear Information System (INIS)

Jurisic, B.; Puvaca, N.

2014-01-01

In order to detect floristic divergence of analysed stands we applied TWINSPAN classification and ordinary Correspondence Analysis. Both analyses have shown an almost identical result of floristic composition, where 114 studied samples were grouped into seven association groups at the third twinspan classification level. These seven groups, successively from the most humid to most dry, comprising two large groups of plant associations, completely corresponding to two alliances: Forest of Pedunculate Oak and Alder and Forest of Pedunculate Oak and Hornbeam. SIMPER procedure have shown tahat within the first 20.51% of cumulative contribution, the floristic divegence among the studied forest stands includes 13 taxa: Carpinus betulus., Fraxinus angustifolia, Quercus cerris, Amorpha fruticosa, Convallaria majalis, Crataegus oxyacantha, Quercus robur, Lysimachia nummularia, Tamus communis, Galium aparine, Rubus caesius, Ulmus carpinifolia and Ajuga reptans. ANOSIM analysis were used to determine the degree of floristic discontinuity. It was largest between forest of Pedunculate Oak, Hornbeam and Turkey Oak and forest of Pedunculate Oak and Ash (statistics R = 0.8824 (p<0.001)). The lowest floristic dissimilarity was between the forest of Pedunculate Oak, Hornbeam and Turkey Oak and forest of Pedunculate Oak, Hornbeam and Turkey Oak with Lindens, where R = 0.2009 (p<0.01). Posavina floodplain forests in Serbia generally show good agreement with analogous communities in neighbouring countries in the Balkan peninsula and Central Europe. (author)

Stand restoration burning in oak-pine forests in the southern Applachians: effects on aboveground biomass and carbon and nitrogen cycling

Science.gov (United States)

Robert M. Hubbard; James M. Vose; Barton D. Clinton; Katherine J. Elliott; Jennifer D. Knoepp

2004-01-01

Understory prescribed burning is being suggested as a viable management tool for restoring degraded oak–pine forest communities in the southern Appalachians yet information is lacking on how this will affect ecosystem processes. Our objectives in this study were to evaluate the watershed scale effects of understory burning on total aboveground biomass, and the carbon...

Sudden oak death: disease trends in Marin county plots after one year

Science.gov (United States)

Brice A. McPherson; David L. Wood; Andrew J. Storer; Nina Maggi Kelly; Richard B. Standiford

2002-01-01

Sudden oak death has emerged as a major threat to the oak forests of California. In oaks and tanoak, this disease complex consists of a previously unreported fungus-like pathogen, Phytophthora ramorum, insects (bark and ambrosia beetles), and a secondary fungus, Hypoxylon thouarsianum. Species monitored in this study were coast...

Size as Leading Indicator among Scandinavian Constructor Compagnies

DEFF Research Database (Denmark)

Bentzen, Eric

This paper studies predictability of stock marked prices in the Scandinavian constructor market.......This paper studies predictability of stock marked prices in the Scandinavian constructor market....

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

Science.gov (United States)

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

2012-01-01

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

Regional and geomorphic influence on the productivity, composition, and structure of oak ecosystems in the western central hardwoods region

Science.gov (United States)

Amber M. Steele; John M. Kabrick; Randall J. Miles

2013-01-01

The steeply dissected glaciated landscapes of the Chariton River Hills Ecological Subsection (CRHES) in northern Missouri have extensive, but largely unmanaged, oak forests that are relatively unstudied. There is increasing interest in these forests for oak ecosystem restoration, ecological site description, and production of oak timber for biofuels. Our objectives...

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.

Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA

Science.gov (United States)

Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

2014-01-01

Flooding is a defining disturbance in floodplain forests affecting seed germination, seedling establishment, and tree growth. Globally, flood control, including artificial levees, dams, and channelization has altered flood regimes in floodplains. However, a paucity of data are available in regards to the long-term effects of levees on stand establishment and tree growth in floodplain forests. In this study, we used dendrochronological techniques to reconstruct tree recruitment and tree growth over a 90-year period at three stands within a ring levee in the Mississippi River Alluvial Valley (MAV) and to evaluate whether recruitment patterns and tree growth changed following levee construction. We hypothesized that: (1) sugarberry is increasing in dominance and overcup oak (Quercus lyrata) is becoming less dominant since the levee, and that changes in hydrology are playing a greater role than canopy disturbance in these changes in species dominance; and (2) that overcup oak growth has declined following construction of the levee and cessation of overbank flooding whereas that of sugarberry has increased. Recruitment patterns shifted from flood-tolerant overcup oak to flood-intolerant sugarberry (Celtis laevigata) after levee construction. None of the 122 sugarberry trees cored in this study established prior to the levee, but it was the most common species established after the levee. The mechanisms behind the compositional change are unknown, however, the cosmopolitan distribution of overcup oak during the pre-levee period and sugarberry during the post-levee period, the lack of sugarberry establishment in the pre-levee period, and the confinement of overcup oak regeneration to the lowest areas in each stand after harvest in the post-levee period indicate that species-specific responses to flooding and light availability are forcing recruitment patterns. Overcup oak growth was also affected by levee construction, but in contrast to our hypothesis, growth actually

Ash properties of some dominant Greek forest species

International Nuclear Information System (INIS)

Liodakis, S.; Katsigiannis, G.; Kakali, G.

2005-01-01

The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

Ash properties of some dominant Greek forest species

Energy Technology Data Exchange (ETDEWEB)

Liodakis, S. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)]. E-mail: liodakis@central.ntua.gr; Katsigiannis, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece); Kakali, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)

2005-10-15

The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

A new approach in the monitoring of the phytosanitary conditions of forests: the case of oak and beech stands in the Sicilian Regional Parks

Directory of Open Access Journals (Sweden)

Cinzia Rizza

2016-10-01

Full Text Available The objective of this study was to investigate the health conditions of oak and beech stands in the three Regional Parks of Sicily (Etna, Madonie and Nebrodi. A total of 81 sampling areas were investigated, 54 in oak stands and 27 in beech stands. The phytosanitary conditions of each tree within the respective sampling area was expressed with a synthetic index namely phytosanitary class (PC. Oak stands showed severe symptoms of decline, with 85% of the sampling areas including symptomatic trees. In general, beech stands were in better condition, with the exception of Nebrodi Park, where trees showed severe symptoms of decline. On oak trees, infections of fungal pathogens were also observed, including Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides and Armillaria sp. By contrast, on beech trees Biscogniauxia nummularia, Fomes fomentarius and Neonectria radicicola were recognized. Furthermore, twenty-two permanent sampling areas were delimited with the aim of monitoring regularly the health conditions of forests in these three parks.

LandscapeDNDC used to model nitrous oxide emissions from soils under an oak forest in southern England

Science.gov (United States)

Cade, Shirley; Clemitshaw, Kevin; Lowry, David; Yamulki, Sirwan; Casella, Eric; Molina, Saul; Haas, Edwin; Kiese, Ralf

2013-04-01

Nitrous oxide (N2O) is an important greenhouse gas, having a global warming potential of approximately 300 times that of carbon dioxide (CO2), and plays a significant role in depleting stratospheric ozone. Its principal source is microbial activity in soils and waters. Measured values of N2O emissions from soils show high temporal dynamics and a large range as a result of inter-related physico-chemical factors affecting the microbial processes, thus making predictions difficult. Emissions often occur in pulses following re-wetting, frost-thaw or management events such as N-fertilization, which further complicates predictions. Process-based models have been developed to help understand this emission variability and as potential tools for IPCC Tier 3 reporting on national emission inventories. Forests are promoted as sinks for CO2 and can be used as renewable sources of energy or longer term CO2 storage if timber is used in products such as in construction and furniture, provided appropriate replanting takes place. It is important that the effect of any changes in forest management and land use as a result of a desire to reduce CO2 emissions does not increase N2O emissions from forest soils, which are still poorly understood, compared to agricultural soils. LandscapeDNDC (Haas et al 2012) has been developed as a process-oriented model, based on the biogeochemical model, DNDC (Li et al, 1992), in order to simulate biosphere-atmosphere-hydrosphere exchanges at site and regional scales. It can model the carbon and nitrogen turnover and associated greenhouse gas (GHG) emissions of forest, agricultural and grassland ecosystems, and allows modelling of impacts of regional land use change over time. This study uses data (including forest growth, GHG emissions and soil moisture) from an oak forest, known as the Straits Enclosure, at Alice Holt in Hampshire, where extensive measurements have been made by Forest Research since 1995. It involves validation of the site scale

Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink.

Science.gov (United States)

McGarvey, Jennifer C; Thompson, Jonathan R; Epstein, Howard E; Shugart, Herman H

2015-02-01

Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (Liriodendron tulipifera) store the most live biomass, while the mixed oak (Quercus spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.

Patterns of contemporary hybridization inferred from paternity analysis in a four-oak-species forest

Directory of Open Access Journals (Sweden)

Gailing Oliver

2009-12-01

Full Text Available Abstract Background Few studies address the issue of hybridization in a more than two-species context. The species-rich Quercus complex is one of the systems which can offer such an opportunity. To investigate the contemporary pattern of hybridization we sampled and genotyped 320 offspring from a natural mixed forest comprising four species of the European white oak complex: Quercus robur, Q. petraea, Q. pubescens, and Q. frainetto. Results A total of 165 offspring were assigned unambiguously to one of the pollen donors within the study plot. The minimum amount of effective pollen originating from outside the plot varied markedly among the seed parents, ranging from 0.18 to 0.87. The majority of the successful matings (64.1% occurred between conspecific individuals indicating the existence of reproductive barriers between oak species. However, the isolation was not complete since we found strong evidence for both first-generation (8.4% and later-generation hybrids (27.5%. Only two out of eight seed parents, belonging to Q. petraea and Q. robur, showed a high propensity to hybridize with Q. pubescens and Q. petraea, respectively. Significant structure of the effective pollen pools (Φpt = 0.069, P = 0.01 was detected in our sample. However, no support was found for the isolation by distance hypothesis. The proportion of hybrids was much higher (79% in the seed generation when compared to the adult tree generation. Conclusion First-generation hybrids were observed only between three out of six possible species combinations. Hybrids between one pair of species preferred to mate with one of their parental species. The observation of first and later-generation hybrids in higher frequency in acorns than in adults might be explained by selection against hybrid genotypes, the history of this uneven-aged forest or past introgression between species.

Evidence of the dynamic response of housing values to a sudden oak death infestation

Science.gov (United States)

Kent F. Kovacs; Thomas P. Holmes; Jeffrey E. Englin; Janice. Alexander

2010-01-01

Sudden oak death (SOD), caused by the non-indigenous forest pathogen Phytophthora ramorum, causes substantial mortality in coast live oak (Quercus agrifolia) and several other oak species on the Pacific Coast of the United States. Quasi-experimental hedonic models examine the effect of SOD on property...

Spatial scaling of core and dominant forest cover in the Upper Mississippi and Illinois River floodplains, USA

Science.gov (United States)

De Jager, Nathan R.; Rohweder, Jason J.

2011-01-01

Different organisms respond to spatial structure in different terms and across different spatial scales. As a consequence, efforts to reverse habitat loss and fragmentation through strategic habitat restoration ought to account for the different habitat density and scale requirements of various taxonomic groups. Here, we estimated the local density of floodplain forest surrounding each of ~20 million 10-m forested pixels of the Upper Mississippi and Illinois River floodplains by using moving windows of multiple sizes (1–100 ha). We further identified forest pixels that met two local density thresholds: 'core' forest pixels were nested in a 100% (unfragmented) forested window and 'dominant' forest pixels were those nested in a >60% forested window. Finally, we fit two scaling functions to declines in the proportion of forest cover meeting these criteria with increasing window length for 107 management-relevant focal areas: a power function (i.e. self-similar, fractal-like scaling) and an exponential decay function (fractal dimension depends on scale). The exponential decay function consistently explained more variation in changes to the proportion of forest meeting both the 'core' and 'dominant' criteria with increasing window length than did the power function, suggesting that elevation, soil type, hydrology, and human land use constrain these forest types to a limited range of scales. To examine these scales, we transformed the decay constants to measures of the distance at which the probability of forest meeting the 'core' and 'dominant' criteria was cut in half (S 1/2, m). S 1/2 for core forest was typically between ~55 and ~95 m depending on location along the river, indicating that core forest cover is restricted to extremely fine scales. In contrast, half of all dominant forest cover was lost at scales that were typically between ~525 and 750 m, but S 1/2 was as long as 1,800 m. S 1/2 is a simple measure that (1) condenses information derived from multi

Single-tree harvesting reduces survival and growth of oak stump sprouts in the Missouri Ozark Highlands

Science.gov (United States)

Daniel C. Dey; Randy G. Jensen; Michael J. Wallendorf

2008-01-01

Regeneration and recruitment into the overstory is critical to the success of using uneven-aged systems to sustain oak forests. We evaluated survival and growth of white oak (Quercus alba L.), black oak (Q. velutina Lam.), and scarlet oak (Q. coccinea Muenchh.) stump sprouts 10 years after harvesting Ozark...

Do Scandinavians Care about International Law?

DEFF Research Database (Denmark)

Wind, Marlene

2016-01-01

Although Scandinavians are often celebrated as the vanguards of human rights and international law, we know little about whether courts and judges in these countries have embraced those international courts and conventions that they themselves helped establish after the Second World War. This art......Although Scandinavians are often celebrated as the vanguards of human rights and international law, we know little about whether courts and judges in these countries have embraced those international courts and conventions that they themselves helped establish after the Second World War...... international law and courts by citing their case law. Building on this author’s previous research, it is argued that Norway sticks out as much more engaged internationally due to a solid judicial review tradition at the national level. It is also argued that Scandinavian legal positivism, has influenced a much...

Scandinavian Semantics and the Human Body

DEFF Research Database (Denmark)

Levisen, Carsten

2015-01-01

, it is demonstrated that Scandinavian and English systems differ significantly in some aspects of the way in which the construe the human body with words. The study ventures an innovative combination of methods, pairing the Natural Semantic Metalanguage (NSM) approach to linguistic and conceptual analysis......This paper presents an ethnolinguistic analysis of how the space between the head and the body is construed in Scandinavian semantic systems vis-a-vis the semantic system of English. With an extensive case study of neck-related meanings in Danish, and with cross-Scandinavian reference...... with empirical evidence from the Evolution of Semantic Systems (EoSS) project. This combination of empirical and interpretative tools helps to integrate evidence from semantics and semiotics, pinning out in great detail the intricacies of the meanings of particular body words. The paper concludes that body words...

Use of damage surveys and field inventories to evaluate oak and sugar maple health in the northern United States

Science.gov (United States)

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

2009-01-01

Oak species (Quercus spp.) and sugar maple (Acer saccharum) are substantial components of the forest ecosystems in the 24-state region spanning the northern U.S. During recent decades, both damage surveys and forest inventories have documented declines of sugar maple and oak health. In order to more fully assess the status of oak and sugar maple health, we examined...

Soil respiration shifts as drought-induced tree substitution advances from Scots pine to Holm oak forest

Science.gov (United States)

Barba, Josep; Curiel Yuste, Jorge; Poyatos, Rafael; Janssens, Ivan A.; Lloret, Francisco

2014-05-01

There is more and more evidences that the current global warming trend and the increase of frequency and intensity of drought events during the last decades in the Northern hemisphere are currently producing an increment of drought-induced forest die-off events, being the Mediterranean region one of the most affected areas. This drought-induced mortality could lead in a vegetation shift with unpredicted consequences in carbon pools, where soils are the most determinant factor in this carbon balance as they contain over two-thirds of carbon on forest ecosystems. There are several uncertainties related on the interaction between soil, environmental conditions and vegetation shifts that could modify their capability to be net carbon sinks or sources in a warming context. We studied soil respiration and its heterotrophic (RH) and autotrophic (Ra) (split in fine roots [Rr] and mycorrhizal respiration [Rs]) components in a mixed Mediterranean forest where Scots pine (Pinus sylvestris L.) are suffering from drought-induced die-off and replaced by Holm oak (Quercus ilex L.) as the dominant tree species. Soil respiration fluxes and its fractions were measured every two weeks during one year at four stages of the substitution process (non defoliated pines [NDP], defoliated pines [DFP], dead pines [DP] and Holm oak [HO]), using the mesh exclusion method. The aims were (i) to describe soil respiration fluxes in a drought-induced secondary successional process, (ii) to test whether the changes in vegetation affected soil respiration fluxes and (iii) to determine the influence of environmental and abiotic variables on the different soil respiration fractions. Total soil respiration was 10.10±6.17 TC ha-1 y-1, RH represented the 67% of the total, Ra represented the 34% of the total, and Rr and Rs were the 22 and 12%, respectively. Significant differences were found in total soil respiration and RH between NDP and HO, being lower in HO than in NDP (34% in total and 48% in RH). No

Environmental analysis of raw cork extraction in cork oak forests in southern Europe (Catalonia--Spain).

Science.gov (United States)

Rives, Jesús; Fernandez-Rodriguez, Ivan; Rieradevall, Joan; Gabarrell, Xavier

2012-11-15

Cork oak grows endemically in a narrow region bordering the western Mediterranean, and especially in the Iberian Peninsula. The importance of cork agro-forestry systems lies in the fact that a natural and renewable raw material - cork - can be extracted sustainably without endangering the tree or affecting biodiversity. This paper describes an environmental analysis of the extraction of raw cork in cork oak forests in Catalonia, using data from five representative local forest exploitations. The evaluation was carried out using life cycle assessment (LCA) methodology, and all the forestry management required to obtain a tonne of raw cork was included. The aim of the study was to evaluate the environmental impacts - in terms of global warming, acidification, eutrophication, human toxicity, and so on - caused by cork extraction and determine the carbon dioxide balance of these forestry systems, with a tree lifespan of about 200 years. During the life cycle extraction of cork in Catalonia, 0.2 kg of CO(2) eq. was emitted per kg of raw cork extracted. Moreover, cork cannot be extracted without the tree, which will be fixing carbon dioxide throughout its technological useful life (200 years), despite the fact that the bark is removed periodically: every 13-14 years. If the emission from extraction and the carbon contained in the material is discounted, the carbon dioxide balance indicates that 18 kg of CO(2) are fixed per kg of raw cork extracted. Therefore, cork is a natural, renewable and local material that can replace other non-renewable materials, at local level, to reduce the environmental impacts of products, and particularly to reduce their carbon footprint. Copyright © 2012 Elsevier Ltd. All rights reserved.

Silvicultural and classificatory analysis of forests of Dnipropetrovsk region

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S. A. Sytnik

2013-11-01

Full Text Available The total forest area of Dnipropetrovsk Region is 198,600 ha, of which 90,800 ha, 45.7% of the total area, comes under the administration of the Forestry and Hunting Department of Dnipropetrovsk Region. 65,700 haor 72.4% of the total surface of the area under the region’s Forestry and Hunting Administration is actually covered by forest vegetation. The most prevalent types of forests in the territory of the Forestry and Hunting Department of Dnipropetrovsk Region (FHDDR are SD1H (dry pine-oak halogenic type, which takes up 13.1% of the forested area of Dnipropetrovsk region, D1H (dry oak halogenic forest – 11.6%, D1BP (dry elm-maple-oak – 10.7%, SB1OP (dry oak-pine – 7.6% D2BP (mesophilous elm-maple-oak – 7.8%, SD1P (dry maple-pine-oak – 6.5%. Forests of the region are classified under environmental, scientific, historical, cultural, recreational and health, protection (erosion control designations. Forests classified as having conservation, scientific, historical and cultural significance cover an area of 13,410 ha (14.8% of the area under Dnipropetrovsk Region’s Forestry and Hunting Administration; recreational forests cover 45,841.5 ha (50.5%. One third of the forests under FHDDR are classified as protective forests. These are anti-erosion forests which cover an area of 31,478.5 ha (34.7%. Commercially exploitable forests do not exist in the region. According to forest regulations the total area protected by the Nature Reserve Fund of Ukraine subordinate to FHDDR is 12,952.6 ha. Objects of state importance are the Dnipro-Oril’ Nature Reserve (3,759.4 ha, wildlife reserves (4,903.1 ha and natural monuments (8,718.5 ha. Areas and sites of local importance include regional landscape parks (2,157.0 ha, wildlife reserves (1,730.0 ha, natural monuments (105.3 ha, park monuments of landscape architecture (208.0 ha, nature reserve boundaries (33.8 ha. The dominant species of conifer is the pine with a total stand area of 16

Forest Disturbance Across the Conterminous United States from 1985-2012: The Emerging Dominance of Forest Decline

Science.gov (United States)

Cohen, Warren B.; Yang, Zhiqiang; Stehman, Stephen; Schroeder, Todd; Bell, David M.; Masek, Jeffrey; Huang, Chengquan; Meigs, Garrett W.

2015-01-01

Evidence of shifting dominance among major forest disturbance agent classes regionally to globally has been emerging in the literature. For example, climate-related stress and secondary stressors on forests (e.g., insect and disease, fire) have dramatically increased since the turn of the century globally, while harvest rates in the western US and elsewhere have declined. For shifts to be quantified, accurate historical forest disturbance estimates are required as a baseline for examining current trends. We report annual disturbance rates (with uncertainties) in the aggregate and by major change causal agent class for the conterminous US and five geographic subregions between 1985 and 2012. Results are based on human interpretations of Landsat time series from a probability sample of 7200 plots (30 m) distributed throughout the study area. Forest disturbance information was recorded with a Landsat time series visualization and data collection tool that incorporates ancillary high-resolution data. National rates of disturbance varied between 1.5% and 4.5% of forest area per year, with trends being strongly affected by shifting dominance among specific disturbance agent influences at the regional scale. Throughout the time series, national harvest disturbance rates varied between one and two percent, and were largely a function of harvest in the more heavily forested regions of the US (Mountain West, Northeast, and Southeast). During the first part of the time series, national disturbance rates largely reflected trends in harvest disturbance. Beginning in the mid-90s, forest decline-related disturbances associated with diminishing forest health (e.g., physiological stress leading to tree canopy cover loss, increases in tree mortality above background levels), especially in the Mountain West and Lowland West regions of the US, increased dramatically. Consequently, national disturbance rates greatly increased by 2000, and remained high for much of the decade. Decline

Oak Wilt: People and Trees, A Community Approach to Management

Science.gov (United States)

J. Juzwik; S. Cook; L. Haugen; J. Elwell

2004-01-01

Version 1.3. This self-paced short course on CD-ROM was designed as a learning tool for urban and community foresters, city administrators, tree inspectors, parks and recreation staff, and others involved in oak wilt management.Click the "View or print this publication" link below to request your Oak Wilt: People and...

Identification of Quercus agrifolia (coast live oak resistant to the invasive pathogen Phytophthora ramorum in native stands using Fourier-transform infrared (FT-IR spectroscopy

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Anna Olivia Conrad

2014-10-01

Full Text Available Over the last two decades coast live oak (CLO dominance in many California coastal ecosystems has been threatened by the alien invasive pathogen Phytophthora ramorum, the causal agent of sudden oak death. In spite of high infection and mortality rates in some areas, the presence of apparently resistant trees has been observed, including trees that become infected but recover over time. However, identifying resistant trees based on recovery alone can take many years. The objective of this study was to determine if Fourier-transform infrared (FT-IR spectroscopy, a chemical fingerprinting technique, can be used to identify CLO resistant to P. ramorum prior to infection. Soft independent modeling of class analogy identified spectral regions that differed between resistant and susceptible trees. Regions most useful for discrimination were associated with carbonyl group vibrations. Additionally, concentrations of two putative phenolic biomarkers of resistance were predicted using partial least squares regression; > 99% of the variation was explained by this analysis. This study demonstrates that chemical fingerprinting can be used to identify resistance in a natural population of forest trees prior to infection with a pathogen. FT-IR spectroscopy may be a useful approach for managing forests impacted by sudden oak death, as well as in other situations where emerging or existing forest pests and diseases are of concern.

[Contribution of tropical upland forests to carbon storage in Colombia].

Science.gov (United States)

Yepes, Adriana; Herrera, Johana; Phillips, Juan; Galindo, Gustavo; Granados, Edwin; Duque, Alvaro; Barbosa, Adriana; Olarte, Claudia; Cardona, María

2015-03-01

The tropical montane forests in the Colombian Andean region are located above 1500 m, and have been heavily deforested. Despite the general presumption that productivity and hence carbon stocks in these ecosystems are low, studies in this regard are scarce. This study aimed to (i) to estimate Above Ground Biomass (AGB) in forests located in the South of the Colombian Andean region, (ii) to identify the carbon storage potential of tropical montane forests dominated by the black oak Colombobalanus excelsa and to identify the relationship between AGB and altitude, and (iii) to analyze the role of tropical mountain forests in conservation mechanisms such as Payment for Environmental Services (PES) and Reducing Emissions from Deforestation and Degradation (REDD+). Twenty six 0.25 ha plots were randomly distributed in the forests and all trees with D > or =10 cm were measured. The results provided important elements for understanding the role of tropical montane forests as carbon sinks. The information produced can be used in subnational initiatives, which seek to mitigate or reduce the effects of deforestation through management or conservation of these ecosystems, like REDD+ or PES. The AGB and carbon stocks results obtained were similar to those reported for lowland tropical forests. These could be explained by the dominance and abundance of C. excelsa, which accounted for over 81% of AGB/carbon. The error associated with the estimates of AGB/carbon was 10.58%. We found a negative and significant relationship between AGB and altitude, but the higher AGB values were in middle altitudes (approximatly = 700-1800 m), where the environmental conditions could be favorable to their growth. The carbon storage potential of these forests was higher. However, if the historical rate of the deforestation in the study area continues, the gross emissions of CO2e to the atmosphere could turn these forests in to an important emissions source. Nowadays, it is clear that tropical

Conservation thinning in secondary forest: negative but mild effect on land molluscs in closed-canopy mixed oak forest in Sweden.

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Birte Rancka

Full Text Available Secondary succession is changing the character of many temperate forests and often leads to closed-canopy stands. In such forests set aside for conservation, habitat management alternatives need to be tested experimentally, but this is rarely done. The Swedish Oak Project compares two often debated alternatives: minimal intervention and non-traditional active management (conservation thinning on plots of each type replicated at 25 sites. We study responses of several taxa, and here report results for land molluscs. They are considered to be sensitive to more open, drier forest and we predicted a negative effect of the thinning (26% reduction of the basal area; mean value for 25 experimental forests. We sampled molluscs in the litter in ten 20 x 25 cm subplots, and by standardised visual search, in each plot. In total, we recorded 53 species of snails and slugs (24 369 individuals and the mean species richness in plots was 17. Two seasons after thinning, mean (± SE species richness had decreased by 1.4 (± 0.9 species in thinning plots, but increased by 0.7 (± 1.0 species in minimal intervention plots, a significant but small change with considerable variation among sites. In matched comparisons with minimal intervention, thinning reduced the overall abundance of molluscs. Most species responded negatively to thinning - but only five of the 53 species were significantly affected, and reproduction seemed to be negatively affected in only one species. An ordination analysis did not reveal any particular change in the species community due to thinning. Thus, the negative effect of conservation thinning on land molluscs was apparently mild - one reason was that many trees, shrubs and other forest structures remained after the treatment. Conservation thinning may be recommended, since other taxa are favoured, but minimal intervention is also a useful form of management for molluscs and saproxylic taxa.

Development of northern red oak rooted cutting and enrichment planting systems

Science.gov (United States)

Matthew H. Gocke; Jamie Schuler; Daniel J. Robison; Barry Goldfarb

2005-01-01

Enrichment planting may provide an efficient means to establish elite northern red oak (Quercus rubra L.) genotypes in recently harvested natural forests. However, planting northern red oak (NRO) seedlings into natural stands has proven difficult in the past, especially when competition and other stress factors are not controlled.

A Scandinavian Public Transport Model? Reform Changes in Denmark, Sweden and Norway

DEFF Research Database (Denmark)

Hansson, Lisa; Lissandrello, Enza; Næss, Petter

2017-01-01

Scandinavian public transport, especially aspects of how the Scandinavian countries (i.e., Sweden, Denmark, and Norway) have created governing structures for a cohesive public transport system, is often cited positively in international research. Scandinavia is often treated as a homogeneous unit...... in public transport research, which sometimes refers to the “Scandinavian model of public transport”. It is not uncommon for conclusions regarding Scandinavian countries to be based on analyses of just one country. Is there actually such a thing as a Scandinavian model of public transport? All around Europe...... the public transport sector is changing, taking public transport governance in various directions. This paper provides an overview of the changes and similarities in public transport governance in Scandinavian countries from the 1970s to 2012, discussing whether it is justifiable to speak of a Scandinavian...

Dominance and Diversity of Bird Community in Floodplain Forest Ecosystem

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Karel Poprach

2015-01-01

Full Text Available The paper is aimed to assessment of diversity and structure of bird community in floodplain forest ecosystem. Authors present results of analyses data on bird communities obtained at two transects in the Litovelské Pomoraví Protected Landscape Area (Czech Republic in the period 1998–2012. Research of bird communities was carried out using the point-count method. The article deals with qualitative and quantitative representation of breeding bird species, including their relation to habitat type (closed floodplain forest, ecotone. Altogether 63 breeding species were recorded at the Vrapač transect and 67 at the Litovelské luhy transect, respectively. To be able to detect all recorded species, 11 out of 14 years of monitoring were needed at the Vrapač transect and all 8 years of monitoring at the Litovelské luhy transect, respectively. Authors show that the values in dominant bird species change significantly among the particular census dates within one season, mainly with respect to their activity and detectability. Results are discussed in the frame of sustainable forest management in floodplain forest ecosystems. The presented article can promote to discussion aimed to management strategy for floodplain forest ecosystems, which ranks among natural habitat types of Community interest protected under the Natura 2000 European network.

The biotransformation of soil biocenosis by micromycetes under introduction of Fagus sylvatica L. to oak-hornbeam forest

Science.gov (United States)

Likhanov, Artur; Bilyera, Nataliya; Sedykh, Olena; Melnychuk, Maksym

2017-04-01

Keywords: micromycetes, beech, soil enzymes, illuminance, Penicillium canescens. European beech (Fagus sylvatica L.) is a commercially valuable tree species. As the potential distribution area for beech forest is restricted by Europe, planting of artificial stands is adopted in this region. Beech introduction can alter ecosystem considerably, but the mechanism of this transformation is not clear. We aimed to define abiotic and biotic parameters affecting floor development in beech stands introduced to the oak-hornbeam forest ecosystem ca.50 years ago in Eastern Europe (Ukraine). The daylight illuminace level was similar (2.9-6.5 klx) for both stands. However, grass cover in beech stands did not exceed 0.1-0.5 % even on sites with illuminace level 7.5-8.3 klx. It does not comply with the commonly used suggestion that shading is the main factor causes forest floor absence in the beech stands. We indicated predominantly biotic factors influencing forest floor formation. Thus, particular edaphon represented by micromycetes was able to inhibit plants and microorganisms. We isolated Penicillium canescens strains from soil under beech stands. These fungi utilized beech root exudates and phenol compounds of leaf litter, and produced biologically active substances caused cytostatic and mutagenic effects. They also accelerated (in 2-3.2 times) soil β-glucosidase activity, but had no effect on phosphatase. The biomass of fungi varied under cultivation of Penicillium canescens strains on Czapek medium with the addition of aqueous extracts of beech leaf litter. The biomass of micromycetes increased on 10-15 % at plant phenols concentrations up to 1 mg mL-1. On the contrary, increasing the concentration of phenols up to 4 mg mL-1resulted in a biomass decrease to 40%. The relationship between the concentration of plant phenols and rate of fungal biomass formation indicates that there is probably seasonal regulation of micromycetes activity in the forest biocenosis. The highest

Limited native plant regeneration in novel, exotic-dominated forests on Hawaii

Science.gov (United States)

Joseph Mascaro; Kristen K. Becklund; R. Flint Hughes; Stefan A. Schnitzer

2008-01-01

Ecological invasions are amajor driver of global environmental change. When invasions are frequent and prolonged, exotic species can become dominant and ultimately create novel ecosystem types. These ecosystems are now widespread globally. Recent evidence from Puerto Rico suggests that exoticdominated forests can provide suitable regeneration sites for native species...

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

Science.gov (United States)

Clinton S. Wright; Robert E. Vihnanek

2014-01-01

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

Oak Ridge Reservation Physical Characteristics and Natural Resources

Energy Technology Data Exchange (ETDEWEB)

Parr, P.D.; Hughes, J.F.

2006-09-19

The topography, geology, hydrology, vegetation, and wildlife of the Oak Ridge Reservation (ORR) provide a complex and intricate array of resources that directly impact land stewardship and use decisions (Fig. 1). The purpose of this document is to consolidate general information regarding the natural resources and physical characteristics of the ORR. The ORR, encompassing 33,114 acres (13,401 ha) of federally owned land and three Department of Energy (DOE) installations, is located in Roane and Anderson Counties in east Tennessee, mostly within the corporate limits of the city of Oak Ridge and southwest of the population center of Oak Ridge. The ORR is bordered on the north and east by the population center of the city of Oak Ridge and on the south and west by the Clinch River/Melton Hill Lake impoundment. All areas of the ORR are relatively pristine when compared with the surrounding region, especially in the Valley and Ridge Physiographic Province (Fig. 2). From the air, the ORR is clearly a large and nearly continuous island of forest within a landscape that is fragmented by urban development and agriculture. Satellite imagery from 2006 was used to develop a land-use/land-cover cover map of the ORR and surrounding lands (Fig. 3). Following the acquisition of the land comprising the ORR in the early 1940s, much of the Reservation served as a buffer for the three primary facilities: the X-10 nuclear research facility (now known as the Oak Ridge National Laboratory [ORNL]), the first uranium enrichment facility or Y-12 (now known as the Y-12 National Security Complex [Y-12 Complex]), and a gaseous diffusion enrichment facility (now known as the East Tennessee Technology Park [ETTP]). Over the past 60 years, this relatively undisturbed area has evolved into a rich and diverse eastern deciduous forest ecosystem of streams and reservoirs, hardwood forests, and extensive upland mixed forests. The combination of a large land area with complex physical characteristics

The impact of cattle and goats grazing on vegetation in oak stands of varying coppicing age

Science.gov (United States)

Papachristou, Thomas G.; Platis, Panayiotis D.

2011-01-01

The effects of cattle and goats grazing on oak shoot growth and herbaceous vegetation in three oak forest stands with different coppicing age (1, 4 and 7 yrs after the clear cutting) were investigated. In April 1997, an experimental area was chosen with three forest stands, which were clear cut in 1996 (CL1996), 1993 (CL1993), and 1990 (CL1990). All stands were grazed by cattle and goats after they were clear cut. In each forest stand, five 10 m × 10 m paired plots were located, which represented grazed and protected patches. Herbage biomass within protected and grazed plots was measured four times each year (spring: May-June, summer: July-August, autumn: September-October, and winter: November-December). Behavioural observations on grazing animals were conducted in the same periods. In both protected and open plots the height and basal diameter of all oak shoots on 5 preselected stumps were measured at the end of five growing periods from 1997 to 2001. All forest stands carried a similar amount of available herbage (averaged over forest stands and growing season, 2614 kg/ha). Grazing animals removed on average 1057 kg/ha throughout the growing period. Cattle mainly consumed herbage (97% of bites) while goats consumed a mixture of oak browse (41% bites), herbaceous species (34% bites), and other woody species browse (25% bites). The height, diameter and volume of oak shoots were affected by grazing. The three forest stands had similar shoot heights in the protected plots in 2001 after 5 years of grazing protection. The volume of oak shoots of the grazed plots were 146.7 cm3 for CL1996, 232.9 cm3 for CL1993, and 239.1 cm3 for CL1990 in 2001 (i.e. 5, 8, and 11 years grazing after the clear cuttings, respectively). The protected plots carried greater volumes of oak shoots, CL1996: 496.0 cm3 (few months grazing before protection), CL1993: 690.0 cm3 (4 years grazing before protection), and CL1990: 344.0 cm3 (7 years grazing before protection). In conclusion, almost

Lignin properties in topsoils of a beech/oak forest after 8 years of manipulated litter fall: relevance of altered input and oxidation of lignin

NARCIS (Netherlands)

Klotzbücher, T.; Strohmeier, S.; Kaiser, K.; Bowden, R.D.; Lajtha, K.; Ohm, H.; Kalbitz, K.

2013-01-01

Background and aims We studied the response of lignin oxidation in soils of a beech/oak forest to changes in litter fall. Additionally we considered possible factors in lignin oxidation, including altered (i) input of fresh organic matter and (ii) fungi-to-bacteria ratios. Methods The field-based

A compartment model of plutonium dynamics in a deciduous forest ecosystem

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

1978-01-01

A linear compartment donor-controlled model was designed to describe and simulate the behaviour of plutonium ( 239 , 240 Pu) in a contaminated deciduous forest ecosystem at Oak Ridge, Tennessee. At steady states predicted by the model, less than 0.25% of the Pu in the ecosystem resides in forest biota. Soil is the major repository of Pu in the forest, and reciprocal exchanges of Pu between soil and litter or soil and tree roots were dominant transfers affecting the ecosystem distribution of Pu. Variation in predicted steady state amounts of Pu in the forest, given variability in the model parameters, indicated that ones ability to develop reliable models of Pu transport in ecosystems will improve with greater precision in data from natural environments and a better understanding of sources of variation in Pu data. (author)

Structure of the community of nesting birds in a ravine oak wood in the valley of the Oskol river

Directory of Open Access Journals (Sweden)

A. A. Atemasov

2016-10-01

Full Text Available This investigation was carried out in a forest on the southern borders of the Central-Russian Upland, on the Prioskolsky plateau, in the Srednedonskoy subprovince of the Pontic steppe province. The aim of this work is to identify the peculiarities of structure and ways of formation of the breeding population of ravine oak forests on the border of two geographic zones. The objectives of the work were to describe quantitative and qualitative characteristics of the population of the nesting birds of ravine oak forests, as well as provide an analysis of the faunogenesic structure of the nesting bird population. To obtain data on the species composition and density of nesting birds we used the line transect method by D. Hayne – Y. Ravkin. The surveys were carried out in 2011–2015 three times per season (April to June. The indicators of the breeding density of each bird species and the totals for each year were calculated. The Polydominant Simpson index was used to characterize species diversity. To evaluate the uniformity we used the calibrated version of G ‘Alatalo index F’. The calculations were performed using the program PAST. In total we observed 34 species of birds over the 5 years of research. The dynamics of the total density of breeding birds in the period researched (2011–2015 showed a maximum in 2013 (1,711 pairs/km2; the average index for the 5 years was 1,288 ± 133 pairs/km2, which is similar to the characteristics of the populations of birds forests of the steppe zone (Donetsk Ridge, Azov Upland. The dominant and subdominant species comprised 32.2–54.7% of the population, indicating a balanced community, in spite of the insular nature of the forest. The absolute dominant in all years was the Chaffinch (an average of 21.2% of the population; subdominant species were the Robin (11.2%, Great Tit (10.5% and the Collared Flycatcher (10.3%. Over a third of the total number of birds are the hollow-nesting birds (37.1%; species

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

Science.gov (United States)

Christine J. Small; James L. Chamberlain

2015-01-01

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

Managing redwood ecosystems using Sudden Oak Death as a silvicultural tool

Science.gov (United States)

Frederick D. Euphrat

2015-01-01

In response to the wave of sudden oak death (SOD), caused by Phytophthora ramorum, sweeping the redwood forest ecosystems of California's North Coast, the role of foresters and other ecosystem managers is being tested. On Bear Flat Tree Farm, near Healdsburg, California, Forest, Soil & Water, Inc. (FSW) has conducted a multi-year,...

Multiple recruitment limitation causes arrested succession in mediterranean cork oak systems

NARCIS (Netherlands)

Acacio, Vanda; Holmgren, Milena; Jansen, Patrick A.; Schrotter, Ondrej

2007-01-01

Lack of tree regeneration and persistency of species-poor shrublands represent a growing problem across Mediterranean evergreen oak forests. What constrains forest regeneration is poorly understood, and restoration attempts have been largely unsuccessful. We assessed the contribution of four

Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S.

Science.gov (United States)

Hadley, J. L.; Kuzeja, P.; Mulcahy, T.; Singh, S.

2008-12-01

Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S. Julian Hadley, Paul Kuzeja, Safina Singh and Thomas Mulcahy Transfers of water vapor from terrestrial ecosystems to the atmosphere affect regional hydrology, weather and climate over short time scales, and forest-atmosphere CO2 exchange affects global climate over long timescales. To better understand these effects for forests dominated by two very different tree species, we measured forest-atmosphere water vapor and CO2 transfers by the eddy flux technique to at two sites in central Massachusetts USA for three years. Average annual evapotranspiration (ET) for a young deciduous forest dominated by red oak (Quercus rubra L., the most abundant tree species in the area), was about 430 mm or 25 percent greater than for a coniferous forest dominated by 100 to 230 year old eastern hemlock (Tsuga canadensis L.). The difference in ET was most pronounced in July and August when the deciduous forest lost about 50 percent more water by ET in the average year (192 mm for oak forest versus 130 mm for hemlock). These data indicate that if deciduous trees with similar physiology to red oak replace hemlocks, summertime ET will increase while summer streamflow, soil water content and the extent of year- round wetlands will decrease. Increased summertime ET should also lead to slightly higher regional atmospheric humidity and precipitation. Hemlock-to-deciduous forest conversion has occurred from North Carolina to southern New England and is continuing northward as a lethal insect pest, the hemlock woolly adelgid (Adelges tsugae Annand) continues to kill hemlocks. Average annual carbon storage for the old hemlock forest in our study was about 3.3 Mg C/ha, nearly equal to the average for the deciduous forest, 3.5 Mg C/ha. This calls into question ecological theory that predicts large declines in the rate of carbon uptake for old forests, and

Analytical approaches to the determination of simple biophenols in forest trees such as Acer (maple), Betula (birch), Coniferus, Eucalyptus, Juniperus (cedar), Picea (spruce) and Quercus (oak).

Science.gov (United States)

Bedgood, Danny R; Bishop, Andrea G; Prenzler, Paul D; Robards, Kevin

2005-06-01

Analytical methods are reviewed for the determination of simple biophenols in forest trees such as Acer (maple), Betula (birch), Coniferus, Eucalyptus, Juniperus (cedar), Picea (spruce) and Quercus (oak). Data are limited but nevertheless clearly establish the critical importance of sample preparation and pre-treatment in the analysis. For example, drying methods invariably reduce the recovery of biophenols and this is illustrated by data for birch leaves where flavonoid glycosides were determined as 12.3 +/- 0.44 mg g(-1) in fresh leaves but 9.7 +/- 0.35 mg g(-1) in air-dried samples (data expressed as dry weight). Diverse sample handling procedures have been employed for recovery of biophenols. The range of biophenols and diversity of sample types precludes general procedural recommendations. Caution is necessary in selecting appropriate procedures as the high reactivity of these compounds complicates their analysis. Moreover, our experience suggests that their reactivity is very dependent on the matrix. The actual measurement is less contentious and high performance separation methods particularly liquid chromatography dominate analyses whilst coupled techniques involving electrospray ionization are becoming routine particularly for qualitative applications. Quantitative data are still the exception and are summarized for representative species that dominate the forest canopy of various habitats. Reported concentrations for simple phenols range from trace level (<0.1 microg g(-1)) to in excess of 500 microg g(-1) depending on a range of factors. Plant tissue is one of these variables but various biotic and abiotic processes such as stress are also important considerations.

Phytophthora ramorum in coast live oak: search for resistance and mechanisms.

Science.gov (United States)

B.A. McPherson; D.L. Wood; S.R. Mori; A. Conrad; P. Bonello

2013-01-01

Despite the presence of Phytophthora ramorum in northern and central California forests since at least 1994, asymptomatic coast live oaks (Quercus agrifolia Née) still remain in heavily infested stands. Coast live oak infection and mortality rates of 5 percent y-1 and 3 percent y-1, respectively, observed in long-term...

The Ecology and Silviculture of Oaks, Second Edition: A new book

Science.gov (United States)

Paul S. Johnson; Stephen R. Shifley; Robert. Rogers

2011-01-01

The second edition of The Ecology and Silviculture of Oaks was recently published (Johnson and others 2009). The approach of the book is fundamentally silvicultural, but the content is based on the premise that eff ective and environmentally sound management and protection of oak forests and associated landscapes must be grounded in ecological...

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

Science.gov (United States)

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

2006-01-01

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

Model of plutonium dynamics in a deciduous forest ecosystem

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

1980-01-01

A linear compartment model with donor-controlled flows between compartments was designed to describe and simulate the behavior of plutonium ( 239 240 Pu) in a contaminated forest ecosystem at Oak Ridge, TN. At steady states predicted by the model, less than 0.25% of the plutonium in the ecosystem resides in biota. Soil is the major repository of plutonium in the forest, and exchanges of plutonium between soil and litter or soil and tree roots were dominant transfers affecting the ecosystem distribution of plutonium. Variation in predicted steady-state amounts of plutonium in the forest, given variability in the model parameters, indicates that our ability to develop models of plutonium transport in ecosystems should improve with greater precision in data from natural environments and a better understanding of sources of variation in plutonium data

The dynamic response of housing values to a forst invasive disease: evidence from a sudden oak death infestation

Science.gov (United States)

Kent Kovacs; Thomas P. Holmes; Jeffrey E. Englin; Janice Alexander

2011-01-01

"Sudden Oak Death" (Phytophthora ramorum) is a non-indigenous forest pathogen which causes substantialmortality of coast live oak (Quercus agrifolia) and several other oak tree species on the Pacific Coast of the United States. We estimated the time path of residential property values subject to oak mortality using a...

Dominant Species in Subtropical Forests Could Decrease Photosynthetic N Allocation to Carboxylation and Bioenergetics and Enhance Leaf Construction Costs during Forest Succession.

Science.gov (United States)

Xiao, Yihua; Liu, Shirong; Tong, Fuchun; Chen, Bufeng; Kuang, Yuanwen

2018-01-01

It is important to understand how eco-physiological characteristics shift in forests when elucidating the mechanisms underlying species replacement and the process of succession and stabilization. In this study, the dominant species at three typical successional stages (early-, mid-, and late-succession) in the subtropical forests of China were selected. At each stage, we compared the leaf construction costs (CC), payback time (PBT), leaf area based N content ( N A ), maximum CO 2 assimilation rate ( P max ), specific leaf area (SLA), photosynthetic nitrogen use efficiency (PNUE), and leaf N allocated to carboxylation ( N C ), and to bioenergetics ( N B ). The relationships between these leaf functional traits were also determined. The results showed that the early-succession forest is characterized with significantly lower leaf CC, PBT, N A , but higher P max , SLA, PNUE, N C , and N B , in relation to the late-succession forest. From the early- to the late-succession forests, the relationship between P max and leaf CC strengthened, whereas the relationships between N B , N C , PNUE, and leaf CC weakened. Thus, the dominant species are able to decrease the allocation of the photosynthetic N fraction to carboxylation and bioenergetics during forest succession. The shift in these leaf functional traits and their linkages might represent a fundamental physiological mechanism that occurs during forest succession and stabilization.

Risk factors of oak decline and regional mortality patterns in the Ozark Highlands of Arkansas and Missouri

Science.gov (United States)

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

2011-01-01

Since the late 1970s, oak decline and mortality have plagued Midwestern-upland oak-hickory forests, particularly species in the red oak group (Quercus Section Lobatae) across the Ozark Highlands of Missouri, Arkansas, and Oklahoma (Dwyer and others 1995). Drought is a common inciting factor in oak decline, while advanced tree age is considered a...

A review of fire and oak regeneration and overstory recruitment

Science.gov (United States)

Daniel C. Dey; Zhaofei Fan

2009-01-01

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

Roost tree selection by northern myotis (Myotis septentrionalis) maternity colonies following prescribed fire in a Central Appalachian Mountains hardwood forest

Science.gov (United States)

Joshua B. Johnson; John W. Edwards; W. Mark Ford; J. Edward Gates

2009-01-01

Following decades of fire suppression in eastern forests, prescribed fire as a tool to restore or enhance oak (Quercus spp.)-dominated communities is gaining widespread acceptance in the Appalachian Mountains and elsewhere. However, the interactions of fire with biotic components such as wildlife that might be impacted by prescribed fire are poorly...

Dampening effects of long-term experimental drought on growth and mortality rates of a Holm oak forest.

Science.gov (United States)

Barbeta, Adrià; Ogaya, Romà; Peñuelas, Josep

2013-10-01

Forests respond to increasing intensities and frequencies of drought by reducing growth and with higher tree mortality rates. Little is known, however, about the long-term consequences of generally drier conditions and more frequent extreme droughts. A Holm oak forest was exposed to experimental rainfall manipulation for 13 years to study the effect of increasing drought on growth and mortality of the dominant species Quercus ilex, Phillyrea latifolia, and Arbutus unedo. The drought treatment reduced stem growth of A. unedo (-66.5%) and Q. ilex (-17.5%), whereas P. latifolia remained unaffected. Higher stem mortality rates were noticeable in Q. ilex (+42.3%), but not in the other two species. Stem growth was a function of the drought index of early spring in the three species. Stem mortality rates depended on the drought index of winter and spring for Q. ilex and in spring and summer for P. latifolia, but showed no relation to climate in A. unedo. Following a long and intense drought (2005-2006), stem growth of Q. ilex and P. latifolia increased, whereas it decreased in A. unedo. Q. ilex also enhanced its survival after this period. Furthermore, the effect of drought treatment on stem growth in Q. ilex and A. unedo was attenuated as the study progressed. These results highlight the different vulnerabilities of Mediterranean species to more frequent and intense droughts, which may lead to partial species substitution and changes in forest structure and thus in carbon uptake. The response to drought, however, changed over time. Decreased intra- and interspecific competition after extreme events with high mortality, together with probable morphological and physiological acclimation to drought during the study period, may, at least in the short term, buffer forests against drier conditions. The long-term effects of drought consequently deserve more attention, because the ecosystemic responses are unlikely to be stable over time.Nontechnical summaryIn this study, we

Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

Science.gov (United States)

Acton, W. Joe F.; Schallhart, Simon; Langford, Ben; Valach, Amy; Rantala, Pekka; Fares, Silvano; Carriero, Giulia; Tillmann, Ralf; Tomlinson, Sam J.; Dragosits, Ulrike; Gianelle, Damiano; Hewitt, C. Nicholas; Nemitz, Eiko

2016-06-01

This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS) and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (using PTR-MS) and eddy covariance (using PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean daytime flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28-day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) isoprene emission algorithms (Guenther et al., 2006). A detailed tree-species distribution map for the site enabled the leaf-level emission of isoprene and monoterpenes recorded using gas-chromatography mass spectrometry (GC-MS) to be scaled up to produce a bottom-up canopy-scale flux. This was compared with the top-down canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant-species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

Nitrogen retention in contrasting temperate forests exposed to high nitrogen deposition

Science.gov (United States)

Staelens, J.; Adriaenssens, S.; Wuyts, K.; Verheyen, K.; Boeckx, P. F.

2011-12-01

A better understanding of factors affecting nitrogen (N) retention is needed to assess the impact of changing anthropogenic N emissions and climatic conditions on N cycling and N loss by terrestrial ecosystems. Retention of N has been demonstrated for a wide range of forests, including ecosystems exposed to chronically enhanced N deposition, but it is still unclear which factors determine this N retention capacity. Therefore, we examined the possible effects of forest type on N retention using stable N isotopes. The study was carried out in adjacent equal-aged deciduous (pedunculate oak (Quercus robur L.)) and coniferous (Scots pine (Pinus sylvestris L.)) stands with a similar stand history and growing on a well-drained sandy soil in a region with enhanced N deposition (Belgium). The N input-output budgets and gross soil N transformation rates differed significantly between the two stands. The forest floor was exposed to a high inorganic N input from atmospheric deposition, which was nearly twice as high in the pine stand (33 ± 2 kg N ha-1 yr-1; mean ± standard error) as in the oak stand (18 ± 1 kg N ha-1 yr-1). The N input was reflected in the soil solution under the rooting zone, but the mean nitrate concentration was eight times higher under pine (19 ± 5 mg N L-1) than under oak (2.3 ± 0.9 mg N L-1). Gross N dynamics in the mineral topsoil were determined by in situ 15N labelling of undisturbed soil cores combined with numerical data analysis. Gross N mineralization was two times faster in the oak soil while nitrate production was two times faster in the pine soil, indicating a dominant effect of vegetation cover on soil N cycling. The higher gross nitrification, particularly due to oxidation of organic N, in the pine soil compared to the oak soil, combined with negligible nitrate immobilization, was in line with the higher nitrate leaching under the pine forest. On a larger spatial and temporal scale, the fate of dissolved inorganic N within these forests

Teaching Scandinavian Interaction Design in West Africa

DEFF Research Database (Denmark)

Sørensen, Jannick Kirk

2016-01-01

Methods for interaction design have emerged and established themselves first in a Scandinavian context, later in US context and in the rest of the developed world. While good usability and good user experiences are important to all users of ICT, the question is whether the methods and techniques ...... Scandinavian Participatory design can be used to localize the learning process and make interaction design methods sensitive to the West African context. The paper is based on the author’s reflection on his experiences teaching interaction design in West Africa.......Methods for interaction design have emerged and established themselves first in a Scandinavian context, later in US context and in the rest of the developed world. While good usability and good user experiences are important to all users of ICT, the question is whether the methods and techniques...

Dendrochronological analysis of white oak growth patterns across a topographic moisture gradient in southern Ohio

Science.gov (United States)

Alexander K. Anning; Darrin L. Rubino; Elaine K. Sutherland; Brian C. McCarthy

2013-01-01

Moisture availability is a key factor that influences white oak (Quercus alba L.) growth and wood production. In unglaciated eastern North America, available soil moisture varies greatly along topographic and edaphic gradients. This study was aimed at determining the effects of soil moisture variability and macroclimate on white oak growth in mixed-oak forests of...

The role of environmental factors in oak decline and mortality in the Ozark Highlands

Science.gov (United States)

John M. Kabrick; Daniel C. Dey; Randy G. Jensen; Michael Wallendorf

2008-01-01

Oak decline is a chronic problem in Missouri Ozark forests. Red oak group species are most susceptible and decline is reportedly more severe on droughty, nutrient-poor sites. However, it was not clear whether greater decline severity was caused by poor site conditions or is simply due to the greater abundance of red oak group species found on poorer sites. We conducted...

Ectomycorrhizal fungal diversity and community structure associated with cork oak in different landscapes.

Science.gov (United States)

Reis, Francisca; Valdiviesso, Teresa; Varela, Carolina; Tavares, Rui M; Baptista, Paula; Lino-Neto, Teresa

2018-05-01

Cork oak (Quercus suber L.) forests play an important ecological and economic role. Ectomycorrhizal fungi (ECMF) are key components for the sustainability and functioning of these ecosystems. The community structure and composition of ECMF associated with Q. suber in different landscapes of distinct Mediterranean bioclimate regions have not previously been compared. In this work, soil samples from cork oak forests residing in different bioclimates (arid, semi-arid, sub-humid, and humid) were collected and surveyed for ectomycorrhizal (ECM) root tips. A global analysis performed on 3565 ECM root tips revealed that the ECMF community is highly enriched in Russula, Tomentella, and Cenoccocum, which correspond to the ECMF genera that mainly contribute to community differences. The ECMF communities from the rainiest and the driest cork oak forests were distinct, with soils from the rainiest climates being more heterogeneous than those from the driest climates. The analyses of several abiotic factors on the ECMF communities revealed that bioclimate, precipitation, soil texture, and forest management strongly influenced ECMF structure. Shifts in ECMF with different hyphal exploration types were also detected among forests, with precipitation, forest system, and soil texture being the main drivers controlling their composition. Understanding the effects of environmental factors on the structuring of ECM communities could be the first step for promoting the sustainability of this threatened ecosystem.

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

Science.gov (United States)

Kriska, David John

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

Changes in composition, structure and aboveground biomass over seventy-six years (1930-2006) in the Black Rock Forest, Hudson Highlands, southeastern New York State.

Science.gov (United States)

Schuster, W S F; Griffin, K L; Roth, H; Turnbull, M H; Whitehead, D; Tissue, D T

2008-04-01

We sought to quantify changes in tree species composition, forest structure and aboveground forest biomass (AGB) over 76 years (1930-2006) in the deciduous Black Rock Forest in southeastern New York, USA. We used data from periodic forest inventories, published floras and a set of eight long-term plots, along with species-specific allometric equations to estimate AGB and carbon content. Between the early 1930s and 2000, three species were extirpated from the forest (American elm (Ulmus americana L.), paper birch (Betula papyrifera Marsh.) and black spruce (Picea mariana (nigra) (Mill.) BSP)) and seven species invaded the forest (non-natives tree-of-heaven (Ailanthus altissima (Mill.) Swingle) and white poplar (Populus alba L.) and native, generally southerly distributed, southern catalpa (Catalpa bignonioides Walt.), cockspur hawthorn (Crataegus crus-galli L.), red mulberry (Morus rubra L.), eastern cottonwood (Populus deltoides Bartr.) and slippery elm (Ulmus rubra Muhl.)). Forest canopy was dominated by red oak and chestnut oak, but the understory tree community changed substantially from mixed oak-maple to red maple-black birch. Density decreased from an average of 1500 to 735 trees ha(-1), whereas basal area doubled from less than 15 m(2) ha(-1) to almost 30 m(2) ha(-1) by 2000. Forest-wide mean AGB from inventory data increased from about 71 Mg ha(-1) in 1930 to about 145 Mg ha(-1) in 1985, and mean AGB on the long-term plots increased from 75 Mg ha(-1) in 1936 to 218 Mg ha(-1) in 1998. Over 76 years, red oak (Quercus rubra L.) canopy trees stored carbon at about twice the rate of similar-sized canopy trees of other species. However, there has been a significant loss of live tree biomass as a result of canopy tree mortality since 1999. Important constraints on long-term biomass increment have included insect outbreaks and droughts.

Bryophyte-dominated biological soil crusts mitigate soil erosion in an early successional Chinese subtropical forest

Directory of Open Access Journals (Sweden)

S. Seitz

2017-12-01

Full Text Available This study investigated the development of biological soil crusts (biocrusts in an early successional subtropical forest plantation and their impact on soil erosion. Within a biodiversity and ecosystem functioning experiment in southeast China (biodiversity and ecosystem functioning (BEF China, the effect of these biocrusts on sediment delivery and runoff was assessed within micro-scale runoff plots under natural rainfall, and biocrust cover was surveyed over a 5-year period. Results showed that biocrusts occurred widely in the experimental forest ecosystem and developed from initial light cyanobacteria- and algae-dominated crusts to later-stage bryophyte-dominated crusts within only 3 years. Biocrust cover was still increasing after 6 years of tree growth. Within later-stage crusts, 25 bryophyte species were determined. Surrounding vegetation cover and terrain attributes significantly influenced the development of biocrusts. Besides high crown cover and leaf area index, the development of biocrusts was favoured by low slope gradients, slope orientations towards the incident sunlight and the altitude of the research plots. Measurements showed that bryophyte-dominated biocrusts strongly decreased soil erosion, being more effective than abiotic soil surface cover. Hence, their significant role in mitigating sediment delivery and runoff generation in mesic forest environments and their ability to quickly colonise soil surfaces after disturbance are of particular interest for soil erosion control in early-stage forest plantations.

Bryophyte-dominated biological soil crusts mitigate soil erosion in an early successional Chinese subtropical forest

Science.gov (United States)

Seitz, Steffen; Nebel, Martin; Goebes, Philipp; Käppeler, Kathrin; Schmidt, Karsten; Shi, Xuezheng; Song, Zhengshan; Webber, Carla L.; Weber, Bettina; Scholten, Thomas

2017-12-01

This study investigated the development of biological soil crusts (biocrusts) in an early successional subtropical forest plantation and their impact on soil erosion. Within a biodiversity and ecosystem functioning experiment in southeast China (biodiversity and ecosystem functioning (BEF) China), the effect of these biocrusts on sediment delivery and runoff was assessed within micro-scale runoff plots under natural rainfall, and biocrust cover was surveyed over a 5-year period. Results showed that biocrusts occurred widely in the experimental forest ecosystem and developed from initial light cyanobacteria- and algae-dominated crusts to later-stage bryophyte-dominated crusts within only 3 years. Biocrust cover was still increasing after 6 years of tree growth. Within later-stage crusts, 25 bryophyte species were determined. Surrounding vegetation cover and terrain attributes significantly influenced the development of biocrusts. Besides high crown cover and leaf area index, the development of biocrusts was favoured by low slope gradients, slope orientations towards the incident sunlight and the altitude of the research plots. Measurements showed that bryophyte-dominated biocrusts strongly decreased soil erosion, being more effective than abiotic soil surface cover. Hence, their significant role in mitigating sediment delivery and runoff generation in mesic forest environments and their ability to quickly colonise soil surfaces after disturbance are of particular interest for soil erosion control in early-stage forest plantations.

Impact and ecosystem service of forest and sacred grove as saviour of water quantity and quality in Garhwal Himalaya, India.

Science.gov (United States)

Jana, Purna; Dasgupta, Sabyasachi; Todaria, Nagendra P

2017-08-29

The present study was conducted in environs of the sacred grove of Garhwal Himalaya, India, with a view to assess the impacts of sacred groves and forests on the quality and quantity of water and also to assess the effect of seasonality on perennial stream quality. Water samples were collected from three randomly selected stream spots of both the sacred grove dominated by deodar (Cedrus deodara) and the non-sacred patch dominated by oak (Quercus leucotrichophora). Water samples from both patches were within the World Health Organization (WHO) standard limits. Based on an already established water quality index, water quality of both patches was safe for domestic and irrigation purposes but needs treatment for drinking purposes. Results of the present study also showed a very prominent impact of forest type as well as management condition on water quality and quantity. The water discharge from an oak forest shows more consistency than the discharge from a deodar forest. Due to the presence of the sacred grove, the area has become the source of good quality water supply during lean season for the surrounding villages. Water quality and quantity differed along with the change in season. The sacred grove and the existing forest leave a great impression on local dwellers, as due to its presence, local dwellers never run out of water supply during the dry season. As a result, the villagers sincerely want to protect the area for the sake of their own well-being.

The application of single-tree selection compared to diameter-limit cutting in an upland oak-hickory forest on the Cumberland Plateau in Jackson County, Alabama

Science.gov (United States)

Callie Jo Schweitzer; Greg Janzen

2012-01-01

Cumberland Plateau region upland oak forests have undergone a myriad of disturbances (including periods of few and minor disturbances). Traditional timber harvesting practices such as diameter-limit cutting have negatively altered species composition and skewed stand structure, especially on medium-quality sites. We assessed the ability of single-tree selection to...

Sudden Oak Death, Phytophthora ramorum: A Persistent Threat to Oaks and Other Tree Species

Science.gov (United States)

S.J. Frankel; K.M. Palmieri

2014-01-01

This paper reviews the status and management of sudden oak death and “sudden larch death” in the urban and wildland forests of California, Oregon, and the UK. The causal pathogen, Phytophthora ramorum, was discovered in all three locations over a decade ago; however, efforts to contain and eliminate infestations have been unsuccessful. These less...

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

Science.gov (United States)

Gerald J. Gottfried; Peter F. Ffolliott

2013-01-01

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

Sudden oak death effects on the dynamics of dead wood

Science.gov (United States)

Richard C. Cobb; Jo& atilde; o Filipe A.N.; Margaret R. Metz; Ross K. Meentemeyer; David M. Rizzo

2013-01-01

Sudden oak death has impacted forests notable for high-fire risk and contiguous host communities in California and Oregon coastal forest ecosystems. The disease continues to emerge in stands and landscapes with a large biomass of tanoak (Notholithocarpus densiflorus (Hook.&Arn.) Manos, Cannon & S.H.Oh), and we show that woody debris also...

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

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

Science.gov (United States)

Corinne S. Mann; Andrew R. Forbes

2007-01-01

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

An index for the assessment of degraded Mediterranean forest ecosystems

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Giuseppe Modica

2015-12-01

Full Text Available Aim of study: Diagnosing the degradation degree of forest ecosystems is the basis for restoration strategies. However, there is no literature documenting how to quantify the forest degradation degree by using synthetic indicators, also because there is not a widely accepted definition for "forest degradation" and "degraded forest". Although there are many definitions of forest degradation that converge on the loss of ecosystem services, still today there are no largely accepted methods that give operational guidance to help in defining it. In the present research, with the aim to assess the degree of forest degradation, an integrated index - FDI, Forest Degradation Index - was developed.Area of study: In this first application, the FDI was applied and validated at stand level in two different Mediterranean forest types in two different case studies: Madonie and Nedrodi regional Parks (Sicily, Italy. The first dominated by sessile oak [Quercus petraea (Matt. Liebl. subsp. austrotyrrhenica Brullo, Guarino & Siracusa], the second dominated by cork oak (Quercus suber L..Material and methods: FDI is a synthetic index structured starting from representative and relatively easily detectable parameters. Here, we propose a set of six indicators that should be assessed to determine the forest degradation: Structural Index (SI, Canopy Cover (CC, Natural Regeneration Density (NRD, Focal Species of Degradation (FSD, Coarse Woody Debris (CWD, and Soil Depth (SD. FDI, here proposed and discussed, has been based on a MCDA (Multi-Criteria Decision Analysis approach using the Analytic Hierarchy Process (AHP technique, and implemented in order to contribute in finding simple indicators useful for forest restoration purposes that have an eco-functional basis.Main results: An integrated index of forest degradation has been defined. FDI values are comprised in the closed interval [0, 10], ranging from class I (Higher ecological functionality to class IV (Lower

Production potential and stability of a broadleaved mixed oak/hornbeam forest stand situated on a eutrophic site, Ždánický les

Directory of Open Access Journals (Sweden)

Václav Hurt

2012-01-01

Full Text Available The paper focuses on assessing the growth and production of a mixed oak/hornbeam forest stand established by combined regeneration in 1940 to 1942. The stand is situated at an altitude of 460 m. Since 1961, it is left to its natural development. The 25–year–old stand was characterized as an individually mixed, both diameter- and height-differentiated pole-stage stand. The proportion of tree species was as follows: sessile oak 77 %, hornbeam 19 %, birch 1 %, lime 1 %, black poplar 1 %, wild cherry tree, wild service tree, and field maple. During 41 years of measurements, the proportion of oak slightly decreased to 76 %, on the other hand, the proportion of hornbeam increased to 22%. The initial growing stock of the 25–year–old stand, 75 m3.ha−1, increased to 323 m3.ha−1 at an age of 66 years in 2008. At present, current volume increment ranged between 6.3 m3.ha−1.year−1 and 11.6 m3.ha−1.year−1 during years 1967 and 1998. Since the age of 61, the growth of the stand has decreased and then even ceased due to increased mortality of oak.

Study of the sap-flow and related quantities of oak trees in field experiments

International Nuclear Information System (INIS)

Kanalas, P.; Olah, V.; Szoelloesi, E.; Meszaros, I.; Ander, I.; Fenyvesi, A.

2009-01-01

Complete text of publication follows. Climatology model calculations for the next decades in the Carpathian Basin predict more frequent occurrence of meteorological extremes and, especially, longer droughts with elevated average temperatures during the growing season. A drift of the transition zone between the wooden steppe and the forest regions is predicted, too, resulting in significant reduction and alteration of the climazonal forest communities in the mountainous regions. The aim of our project is obtaining information on the climatic sensitivity of the tree species in the sessile oak - Austrian oak forest stand of the Sikfoekut Project Long Term Ecological Research (LTER) area (Buekk Mountains, NE Hungary). 'Campaign-like' complex field measurements have been performed in contrasting vegetation seasons of 2007 and 2008. As a function of time, stomatal conductance and intensity of sap-flow and stem diameter of Quercus petraea and Quercus cerris trees were measured simultaneously with photosynthetic photon flux density (PPFD), atmospheric pressure, temperature and relative humidity and vapour pressure deficit (VPD) of air, precipitation and soil moisture. It was found that the two oak species of forest stand exhibit similar daily course of stomatal conductance in rainy periods. However, during drought stomatal conductance of Quercus cerris was higher, and after a transitional decrease around midday it exhibited a second maximum in late afternoon. In dry days after a maximum of stomatal conductance at early morning the stomatal closure of Quercus petraea was permanent which might result in 'carbon starvation' of trees if drought is too long. During rainy periods, sap-flow of both species changed in correlation with VPD. In dry period this correlation weakened especially in case of Quercus petraea but a stronger correlation of sap-flow maximum appeared with the decreasing soil moisture content. Quercus cerris showed smaller stem radial variation, than Quercus

Modeling the health and productivity of Oak Savannas in central USA

Science.gov (United States)

Nightingale, J. M.; Hill, M. J.

2012-12-01

Oak species have a long history of domination in eastern North America and their present distribution in various regions exceeds that recorded in the original forests at the time of European settlement. The increase in oak during the late 18th and 19th centuries can be attributed to historical changes in disturbance regimes in the eastern biome. The expansion in oak distribution has occurred on xeric or nutrient-poor sites, which indicates the stress tolerance capabilities of many oak species. The aim of this research is to assess the health and productivity of the fragmented oak savannas that span from Texas north to the Canada border using statewide GAP, climate and MODIS data and the 3PGS (Physiological Principles Predicting Growth using satellite data) ecosystem process model. 3-PGS is a simple big-leaf productivity model that sets upper limits on monthly gross primary productivity (GPP) by determining the amount of photosynthetically active radiation absorbed (APAR) by vegetation and the photosynthetic capacity (LUE) of the canopy. The utilized portion of APAR is calculated by reducing total PAR by an amount determined by the most constraining of a series of environmental modifiers that affect gas exchange through stomata. These include: (a) high daytime atmospheric VPD; (b) soil water availability; and (c) the frequency of sub-freezing temperatures (<-2 °C). Climate data including day length, precipitation, average temperature and vapor pressure deficit are obtained from the Daymet daily gridded surface data from Oak Ridge National Laboratory (ORNL). The fraction of APAR is obtained from the MODIS terra/aqua combined product. Monthly surfaces were derived for the study period 2003-2008 spanning available MODIS and Climate datasets. Soil properties for the entire U.S.A., derived from luster analysis of STATSGO soil parameters, terrain and climate observations were obtained from ORNL. Oak savannas within this region are identified using the statewide Gap

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

Science.gov (United States)

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

2018-01-01

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

Understanding old-growth red and white pine dominated forests in Ontario. Forest fragmentation and biodiversity project technical report No. 2

Energy Technology Data Exchange (ETDEWEB)

Carleton, T.J.; Gordon, A.M.

1992-01-01

In summer 1991, a variety of forest stands dominated by old specimens of white pine and red pine were sampled across a representative portion of the species' range in northcentral Ontario. Plots were established in 40 stands of those surveyed to identify the salient structural components of old-growth, to survey the floristic composition (vascular plants and autotrophic non- vascular plants), to survey site characteristics, and to estimate the links in understorey alpha diversity with site conditions and stand structure. Long-term objectives include a definition of old- growth pine forest, recognition criteria, and prospective management options. Forest stand structure was enumerated through mapping, mensurational, and age estimation techniques. Forest vegetation, including over and understorey species, was non- destructively sampled and a range of data on stand and soil-site variables was also collected in conjunction with information on stand variables peculiar to old growth forests.

Host preference of the vector beetle, host resistance, and expanding patterns of Japanese oak wilt in a stand

Science.gov (United States)

Kazuyoshi Futai; Hiroaki Kiku; Hong-ye Qi; Hagus Tarn; Yuko Takeuchi; Michimasa. Yamasaki

2012-01-01

Since the early 1980s, an epidemic forest disease, Japanese Oak Wilt (JOW), has been spreading from coastal areas along the Sea of Japan to the interior of Honshu island and has been devastating huge areas of forests by killing an enormous number of oak trees in urban fringe mountains, gardens, and parks. The disease is caused by a fungus, Raffaelea...

Causes and consequences of past and projected Scandinavian summer temperatures, 500-2100 AD.

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Ulf Büntgen

Full Text Available Tree rings dominate millennium-long temperature reconstructions and many records originate from Scandinavia, an area for which the relative roles of external forcing and internal variation on climatic changes are, however, not yet fully understood. Here we compile 1,179 series of maximum latewood density measurements from 25 conifer sites in northern Scandinavia, establish a suite of 36 subset chronologies, and analyse their climate signal. A new reconstruction for the 1483-2006 period correlates at 0.80 with June-August temperatures back to 1860. Summer cooling during the early 17th century and peak warming in the 1930s translate into a decadal amplitude of 2.9°C, which agrees with existing Scandinavian tree-ring proxies. Climate model simulations reveal similar amounts of mid to low frequency variability, suggesting that internal ocean-atmosphere feedbacks likely influenced Scandinavian temperatures more than external forcing. Projected 21st century warming under the SRES A2 scenario would, however, exceed the reconstructed temperature envelope of the past 1,500 years.

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

Science.gov (United States)

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

1999-01-01

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

Structure, Composition and Dominance � Diversity Relations in Three Forest Types of a Part of Kedarnath Wildlife Sanctuary, Central Himalaya, India

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Dinesh Prasad SEMWAL

2010-09-01

Full Text Available Plant diversity assessment was carried out on the basis of species richness, tree crown cover and dominance-diversity pattern in different forests of Kedarnath Wildlife Sanctuary (KWLS, Central Himalaya, India during 2006-2009. The maximum tree species richness (10 spp. was observed in Rhododendron arboreum Sm. dominated mixed forest and minimum in Quercus leucotrichophora A. Camus. forest (8 spp.. Maximum tree density (170 trees/ha and high importance value index (89.68 was found in Q. semecarpifolia Sm. forest. Mixed Rhododendron arboreum Sm. forest showed high tree diversity (H=0.96, while shrub were found highest in Quercus leucotrichophora A. Camus forest (H=0.62 and herb diversity in Q. semecarpifolia Sm.forest (H=0.73 respectively Maximum tree crown cover (82% was observed in Rhododendron arboreum Sm. dominated mixed forest while minimum tree crown cover (58% was observed in Q. semecarpifolia Sm. forest. In general random distribution pattern (A/F ratio was observed in all three types of forest. Alterations of land use pattern and population pressure are found to be main cause of increase in resources exploitation and that ultimately decreases species richness and diversity. Agro-forestry, alternate use of sites for resources and providing a recovery period to the forests are some of the strategies suggested for forest conservation, management and sustainable utilization of resources by the local people.

Lighting intensity of the soilsurface and restocking of oak groves

Science.gov (United States)

Slepykh, Victor; Zubko, Anna; Povolotckaia, Nina

2016-04-01

Oak groves of Caucasian Mineral Vody region (CMVR) possess a high ecological and balneological potential which defines the significance of their preservation and reproduction [1]. The role assessment of lighting intensity on renewal of oak groves was carried out on four trial squares (ts) in natural sixty-seven years old forest stand with prevalence of English oak (Quercus robur L.) with unimodal sity (type of the habitat - C1). The illumination was measured at the grass level by the universal measuring instrument of meteoparameters ATT-9508 with an illumination sensor of ATA-1591. The assessment of reforestation was carried out according to the established standards [2]. In the winter of 2005 there was conducted a selecting cutting cabin of the forest stand according to a local method on ts2 with intensity 30%, on ts4 - 50% after which the illumination on the soil surface in relation to illumination of an open place in the summer of 2005 increased from 4.9% to 33.9% on ts2, and from 5.9% to 24.4% on ts4. But by 2014 the illumination decreased till 3.0% on ts2, till 5.4% on ts4 because of an intensive soil grassing down. The control was carried out by ts1 and ts3 on which from 2005 to 2014 the illumination of the soil surface decreased from 4 to 2% as a result of the development of all storeys. As a result due to an intensive soil grassing-down, the total quantity of young oak trees decreased from 2005 to 2014 from 25.6 thousand pcs/ha to 5.9 thousand pcs/ha on ts2; on from 17.3 thousand pcs/ha to 4.0 thousand pcs/ha on ts4. At the same time the total quantity of young oak trees on control squares increased respectively for 1.4% (from 18.8 thousand pcs/ha to 19.1 thousand pcs/ha) on ts1, for 38.7% (from 25.2 thousand pcs/ha to 41.1 thousand pcs/ha). The experiment showed that small young oak trees perishes in the first years of their life from a lack of light and competition from grasland vegetation without providing successful reforestation. Conclusion. So it is

Use of ESI-FTICR-MS to Characterize Dissolved Organic Matter in Headwater Streams Draining Forest-Dominated and Pasture-Dominated Watersheds.

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YueHan Lu

Full Text Available Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS has proven to be a powerful technique revealing complexity and diversity of natural DOM molecules, but its application to DOM analysis in grazing-impacted agricultural systems remains scarce. In the present study, we presented a case study of using ESI-FTICR-MS in analyzing DOM from four headwater streams draining forest- or pasture-dominated watersheds in Virginia, USA. In all samples, most formulas were CHO compounds (71.8-87.9%, with other molecular series (CHOS, CHON, CHONS, and CHOP (N, S accounting for only minor fractions. All samples were dominated by molecules falling in the lignin-like region (H/C = 0.7-1.5, O/C = 0.1-0.67, suggesting the predominance of allochthonous, terrestrial plant-derived DOM. Relative to the two pasture streams, DOM formulas in the two forest streams were more similar, based on Jaccard similarity coefficients and nonmetric multidimensional scaling calculated from Bray-Curtis distance. Formulas from the pasture streams were characterized by lower proportions of aromatic formulas and lower unsaturation, suggesting that the allochthonous versus autochthonous contributions of organic matter to streams were modified by pasture land use. The number of condensed aromatic structures (CAS was higher for the forest streams, which is possibly due to the controlled burning in the forest-dominated watersheds and suggests that black carbon was mobilized from soils to streams. During 15-day biodegradation experiments, DOM from the two pasture streams was altered to a greater extent than DOM from the forest streams, with formulas with H/C and O/C ranges similar to protein (H/C = 1.5-2.2, O/C = 0.3-0.67, lipid (H/C = 1.5-2.0, O/C = 0-0.3, and unsaturated hydrocarbon (H/C = 0.7-1.5, O/C = 0-0.1 being the most bioreactive groups. Aromatic compound formulas including CAS were preferentially removed during combined light

Characterization of the cork oak transcriptome dynamics during acorn development.

Science.gov (United States)

Miguel, Andreia; de Vega-Bartol, José; Marum, Liliana; Chaves, Inês; Santo, Tatiana; Leitão, José; Varela, Maria Carolina; Miguel, Célia M

2015-06-25

Cork oak (Quercus suber L.) has a natural distribution across western Mediterranean regions and is a keystone forest tree species in these ecosystems. The fruiting phase is especially critical for its regeneration but the molecular mechanisms underlying the biochemical and physiological changes during cork oak acorn development are poorly understood. In this study, the transcriptome of the cork oak acorn, including the seed, was characterized in five stages of development, from early development to acorn maturation, to identify the dominant processes in each stage and reveal transcripts with important functions in gene expression regulation and response to water. A total of 80,357 expressed sequence tags (ESTs) were de novo assembled from RNA-Seq libraries representative of the several acorn developmental stages. Approximately 7.6 % of the total number of transcripts present in Q. suber transcriptome was identified as acorn specific. The analysis of expression profiles during development returned 2,285 differentially expressed (DE) transcripts, which were clustered into six groups. The stage of development corresponding to the mature acorn exhibited an expression profile markedly different from other stages. Approximately 22 % of the DE transcripts putatively code for transcription factors (TF) or transcriptional regulators, and were found almost equally distributed among the several expression profile clusters, highlighting their major roles in controlling the whole developmental process. On the other hand, carbohydrate metabolism, the biological pathway most represented during acorn development, was especially prevalent in mid to late stages as evidenced by enrichment analysis. We further show that genes related to response to water, water deprivation and transport were mostly represented during the early (S2) and the last stage (S8) of acorn development, when tolerance to water desiccation is possibly critical for acorn viability. To our knowledge this work

Predicting the economic costs and property value losses attributed to sudden oak death damage in California (2010-2020)

Science.gov (United States)

Kent Kovacs; Tomas Václavík; Robert G. Haight; Arwin Pang; Nik J. Cunniffe; Christopher A. Gilligan; Ross K. Meentemeyer

2011-01-01

Phytophthora ramorum, cause of sudden oak death, is a quarantined, non-native, invasive forest pathogen resulting in substantial mortality in coastal live oak (Quercus agrifolia) and several other related tree species on the Pacific Coast of the United States. We estimate the discounted cost of oak treatment, removal, and...

Thinning young oak stands for small mine timbers - at a profit

Science.gov (United States)

Stanley M. Filip

1949-01-01

Young red oak-white oak stands in the Anthracite Forest Region of Pennsylvania occupy nearly 3/4 million acres of land (fig. 1). At present they are a source of lagging, forepoles, and small props used in the coal mines. Under good cutting practice, a substantial quantity of these mine timbers could be produced by thinning these stands, which would at the same time...

Temperate forest development during secondary succession: effects of soil, dominant species and management

NARCIS (Netherlands)

Bose, A.K.; Schelhaas, M.; Mazerolle, M.J.; Bongers, F.

2014-01-01

With the increase in abandoned agricultural lands in Western Europe, knowledge on the successional pathways of newly developing forests becomes urgent. We evaluated the effect of time, soil type and dominant species type (shade tolerant or intolerant) on the development during succession of three

Scandinavian exceptionalism in anti-doping within sport

DEFF Research Database (Denmark)

Tangen, Jan Ove; Møller, Verner

2017-01-01

Why are Scandinavian countries so committed to the cause of antidoping? In this paper, we propose that the Scandinavian mentality, formed by paternalistic welfare models, is a useful framework for understanding anti-doping. We focus on anti-doping policy and work in Norway and Denmark. We start w......: the Norwegian self-image and its impact on politics, and Danish amateurism and corrupt idealism. We conclude that Nordic antidoping is pursued with rigour and determination, and suggest this is rooted in the Nordic countries’ exceptional social-welfare ideology and strong paternalism....

Responses of northern red oak seedlings to lime and deer exclosure fencing in Pennsylvania

Science.gov (United States)

Robert P. Long; Patrick H. Brose; Stephen B. Horsley

2012-01-01

In Pennsylvania, two hypotheses compete to explain the chronic oak (Quercus spp.) regeneration problem: excessive deer browsing and soil cation depletion. We tested these hypotheses by evaluating the effect of forest liming and deer exclosure fencing on northern red oak (Quercus rubra L.) seedling growth and nutrition in five...

Imprint of oaks on nitrogen availability and δ15N in California grassland-savanna: A case of enhanced N inputs?

Science.gov (United States)

Perakis, S.S.; Kellogg, C.H.

2007-01-01

Woody vegetation is distributed patchily in many arid and semi-arid ecosystems, where it is often associated with elevated nitrogen (N) pools and availability in islands of fertility. We measured N availability and δ15N in paired blue-oak versus annual grass dominated patches to characterize the causes and consequences of spatial variation in N dynamics of grassland-savanna in Sequoia-Kings Canyon National Park. We found significantly greater surface soil N pools (0–20 cm) in oak patches compared to adjacent grass areas across a 700 m elevation gradient from foothills to the savanna-forest boundary. N accumulation under oaks was associated with a 0.6‰ depletion in soil δ15N relative to grass patches. Results from a simple δ15N mass balance simulation model, constrained by surface soil N and δ15N measured in the field, suggest that the development of islands of N fertility under oaks can be traced primarily to enhanced N inputs. Net N mineralization and percent nitrification in laboratory incubations were consistently higher under oaks across a range of experimental soil moisture regimes, suggesting a scenario whereby greater N inputs to oak patches result in net N accumulation and enhanced N cycling, with a potential for greater nitrate loss as well. N concentrations of three common herbaceous annual plants were nearly 50% greater under oak than in adjacent grass patches, with community composition shifted towards more N-demanding species under oaks. We find that oaks imprint distinct N-rich islands of fertility that foster local feedback between soil N cycling, plant N uptake, and herbaceous community composition. Such patch-scale differences in N inputs and plant–soil interactions increase biogeochemical heterogeneity in grassland-savanna ecosystems and may shape watershed-level responses to chronic N deposition.

A contribution to the sessile oak site and beech site defining in central Serbia

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Krstić Milun

2009-01-01

Full Text Available The study was carried out in sessile oak forests and beech forests in the region central Serbia. The stands are classified as pure stands with the percentage of other species up to 10% per tree number, mixed forests of sessile oak with other species, and mixed forests of beech with other species, whose percentage does not exceed 50%. Altogether 257 stands were monitored - 202 beech stands and 55 sessile oak stands. By the applied method of defining the local heat potential (Lujić, 1960, modified by Ratknić et al. (2001 and Krstić (2004, 2008, which represents possibility of soil heating without vegetation, were determined. In this way, a scale of 162 possible combinations of local heat potential was obtained, which explains more precisely the dependence of beech stands and sessile oak stands on the topographic conditions. By applying the weighted values of the thermal co-ordinates of aspect and slope (E for each altitudinal belt of 100 m, it was concluded that pure stands have the widest ecological range. Pure beech stands occur at the sites with 34 combinations of thermal co-ordinates E.V=4.6 to 8.12. Pure sessile oak stands occur at the sites with 12 combinations of thermal co-ordinates E.V=5.10 to 8.11. The percentage of mixed beech stands with other broadleaf species is the highest at the sites with the co-ordinate V=10-11 (at the altitudes between 700 and 900 m is about 60 %. Mixed stands of sessile oak and beech are located on the terrains with combinations of thermal co-ordinates E.V=7.9 to 8.12. By using the local heat potential of a region, it can be identified which sites, i.e. which combinations of exposure, slope and altitude belong to the particular tree species. Consequently, a more reliable selection of tree species can be done for the bio-reclamation of barrens and other deforested terrains.

Oak management for wood products

Science.gov (United States)

Roger Barlow

1971-01-01

A method is presented for analyzing oak management alternatives through comparisons of the present value of the net cash flow produced. Even-aged management without age-class regulation returned $72.60 of present value over a 40-year period. In the next 40 years the only expenses reduce the present value to $72.43. To regulate this stand into a forest with an equal...

Comparison of seasonal variations of ozone exposure and fluxes in a Mediterranean Holm oak forest between the exceptionally dry 2003 and the following year

International Nuclear Information System (INIS)

Gerosa, Giacomo; Finco, Angelo; Mereu, Simone; Vitale, Marcello; Manes, Fausto; Denti, Antonio Ballarin

2009-01-01

Ozone and energy fluxes have been measured using the eddy covariance technique, from June to December 2004 in Castelporziano near Rome (Italy), and compared to similar measurements made in the previous year. The studied ecosystem consisted in a typical Mediterranean Holm oak forest. Stomatal fluxes have been calculated using the resistance analogy and by inverting the Penmann-Monteith equation. Results showed that the average stomatal contribution accounts for 42.6% of the total fluxes. Non-stomatal deposition proved to be enhanced by increasing leaf wetness and air humidity during the autumnal months. From a comparison of the two years, it can be inferred that water supply is the most important limiting factor for ozone uptake and that prolonged droughts alter significantly the stomatal conductance, even 2 months after the soil water content is replenished. Ozone exposure, expressed as AOT40, behaves similarly to the cumulated stomatal flux in dry conditions whereas a different behaviour for the two indices appears in wet autumnal conditions. A difference also occurs between the two years. - Ozone fluxes to a Holm oak coastal forest show inter-annual variations depending on meteorological conditions and water availability.

Scandinavian Object Shift and Optimality Theory

DEFF Research Database (Denmark)

Engels, Eva; Vikner, Sten

This study presents an account of object shift, a word order phenomenon found in most of the Scandinavian languages where an object occurs unexpectedly to the left and not to the right of a sentential adverbial. The book examines object shift across many of the Scandinavian languages and dialects...... and original observations, this book is an important addition to the fields of phonology, optimality theory and theoretical syntax......., and analyses the variation, for example whether object shift is optional or obligatory, whether it applies only to pronouns or other objects as well, and whether it applies to adverbials. The authors show that optimality theory, traditionally used in phonology, is a useful framework for accounting...

Changes in forest structure since 1860 in ponderosa pine dominated forests in the Colorado and Wyoming Front Range, USA

Science.gov (United States)

Mike A. Battaglia; Benjamin Gannon; Peter M. Brown; Paula J. Fornwalt; Antony S. Cheng; Laurie S. Huckaby

2018-01-01

Management practices since the late 19th century, including fire exclusion and harvesting, have altered the structure of ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) dominated forests across the western United States. These structural changes have the potential to contribute to uncharacteristic wildfire behavior and effects. Locally-...

Communities of fungi in decomposed wood of oak and pine

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Kwaśna Hanna

2016-09-01

Full Text Available The abundance and diversity of wood decomposing fungi were investigated by isolating and cultivating filamentous fungi from wood and by detection of fruit bodies of ascomycetous and basidiomycetous fungi. The objective was to study the impact of forest management on fungi in 100-year-old oak and 87-year-old Scots pine forests in Northern Poland. Fungi were found on coarse woody debris of decayed stumps and fallen logs, boughs and branches in each of the three (managed and unmanaged examined stands. In total, 226 species of Oomycota and fungi were recorded. Oak wood was colonized by one species of Oomycota and 141 species of fungi including Zygomycota (19 species, Ascomycota (103 species and Basidiomycota (19 species. Scots pine wood was also colonized by one species of Oomycota and 138 species of fungi including Zygomycota (19 species, Ascomycota (90 species and Basidiomycota (29 species. In the first, second and third stages of decomposition, the oak wood was colonized by 101, 89 and 56 species of fungi respectively and pine wood was colonized by 82, 103 and 47 species respectively. Eighty three of the observed species (37% occurred on both types of wood, while the other species displayed nutritional preferences. A decrease in the number of species with advancing decay indicates the necessity for a continuous supply of dead wood to the forest ecosystem.

Climate effects on cork growth in Cork oak plantations in Sicily (Italy

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2009-03-01

Full Text Available Cork oak (Quercus suber L. is usually dominant in silvopastoral systems in many areas of Sicily, where the trees are debarked periodically for cork production. In spite of the importance of cork and cork oak stands in Sicilian forests and the potential economic scenarios, few research works have been carried out on these systems. Given the importance of cork thickness in cork quality evaluation, the main objective of this work is to study cork growth in cork oak productive stands spread on the north (Nebrodi Mountains and south-east (Iblei Mountains of Sicily. Image analysis techniques were used on cork surfaces of transverse sections of planks to measure cork rings. Dendrochronological analysis was applied to study annual fluctuation on rings growth in relation to various climate parameters in a cork cycle production. Results showed that rainfall, summer drought and temperature are determining factors in controlling cork growth. In siliceous areas of Nebrodi Mountains correlation between cork growth index and rainfall indicates that the rain period from May to September strongly influences phellogen activity. Temperature and water stress indices, on the other hand, show a negative correlation with cork growth. In clay and evolved soils of volcanic plateau of Iblei Mountains January precipitation shows a positive correlation with cork growth index. Also absolute minimum temperature in June and absolute maximum temperature in September show a positive correlation when temperature possibly has influence on phellogen activity during growing season.

Seasonal Variability of Ground Water Levels in the Puszcza Zielonka Forest

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Grajewski Sylwester

2014-07-01

Full Text Available The paper presents results of studies on seasonal variability of ground water tables recorded in long-term observations of water levels in the Puszcza Zielonka forest complex. The Puszcza Zielonka Forest is located in the middle part of the Warta basin in the central part of the Wielkopolska region. Its western boundary is located approx. 6 km north-east of Poznań. The area is situated in the western part of the Wielkopolska-Mazovian climatic region. The natural landscape is of young glacial type of Pleistocene and Holocene formation. For this reason parent materials for soils in this area were mainly postglacial drifts, deposits coming from the Poznań stage of the Würm glaciation. In terms of granulometric composition these were mainly low clayey sands deposited on loose sands with an admixture of gravel and eroded sandy clay. Scots pine is the dominant species. Oaks, alders, larches and scarce spruces are also found in this area. Predominant sites include fresh mixed forest, fresh mixed coniferous forest, fresh broadleaved forest and alder swamp forest.

Attraction of ambrosia and bark beetles to coast live oaks infected by Phytophthora ramorum

Science.gov (United States)

Brice A. McPherson; Nadir Erbilgin; David L. Wood; Pavel Svihra; Andrew J. Storer; Richard B. Standiford

2008-01-01

Sudden oak death, caused by Phytophthora ramorum (Werres, de Cock & Man in?t Veld), has killed thousands of oaks (Quercus spp.) in coastal California forests since the mid-1990s. Bark and ambrosia beetles that normally colonize dead or severely weakened trees selectively tunnel into the bleeding cankers that are the first...

Presentation of radioecology in the Scandinavian countries

International Nuclear Information System (INIS)

Agnedal, P.O.

1980-01-01

One of the working groups dealt with the activity of the committee and in its report it is said that three types for the joint Scandinavian work could be identified: 1. - Projects. 2. - Conferences and training-courses. 3. - Publications and information. Among projects 'Intercalibration' regarding sampling techniques and analytical methods. Transport models, consequences of large accidents, were mentioned and in other groups the same type of projects was given. Another working group dealt with international cooperation in the field of radioecology and in its report it was said that it is important to present the work performed in the Scandinavian countries

Sanitation options for managing oak wood infested with the invasive goldspotted oak borer (Coleoptera: Buprestidae) in Southern California

Science.gov (United States)

Michael I. Jones; Tom W. Coleman; Andrew D. Graves; Mary Louise. Flint; Steven J. Seybold

2013-01-01

Movement of invasive wood-boring insects in wood products presents a threat to forest health and a management challenge for public and private land managers. The goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), is a new pest in San Diego and Riverside Cos., CA, believed to have been introduced on firewood. This beetle...

Regenerating mixed oak stands in Pennsylvania: a quarter-century retrospective

Science.gov (United States)

P. J. Gould; K. C. Steiner; J. C. Finley; M. E. McDill

2003-01-01

The outcomes of regeneration treatments in 90 oak-dominated stands in Pennsylvania are examined 20 to 33 years after treatment. Approximately one-quarter of the stands failed to reach 50 percent stocking after at least 20 years, but most stands regenerated successfully. Red maple is the most frequently observed species in the regenerated stands, followed by oak species...

Genetic diversity and population structure of Raffaelea quercus-mongolicae, a fungus associated with oak mortality in South Korea

Science.gov (United States)

M. -S. Kim; P. A. Hohenlohe; K. -H. Kim; S. -T. Seo; Ned Klopfenstein

2016-01-01

Raffaelea quercus-mongolicae is a fungus associated with oak wilt and deemed to cause extensive oak mortality in South Korea. Since the discovery of this fungus on a dead Mongolian oak (Quercus mongolica) in 2004, the mortality continued to spread southwards in South Korea. Despite continued expansion of the disease and associated significant impacts on forest...

Governing health equity in Scandinavian municipalities

DEFF Research Database (Denmark)

Scheele, Christian Elling; Little, Ingvild; Diderichsen, Finn

2018-01-01

AIMS: Local governments in the Scandinavian countries are increasingly committed to reduce health inequity through 'health equity in all policies' (HEiAP) governance. There exists, however, only very sporadic implementation evidence concerning municipal HEiAP governance, which is the focus...... of this study. METHODS: Data are based on qualitative thematic network analysis of 20 interviews conducted from 2014 to 2015 with Scandinavian political and administrative practitioners. RESULTS: We identify 24 factors located within three categories; political processes, where insufficient political commitment...... to health equity goals outside of the health sector and inadequate economic prioritization budget curbs implementation. Concerning evidence, there is a lack of epidemiological data, detailed evidence of health equity interventions as well as indicators relevant for monitoring implementation. Concerted...

Economic evaluation of intermediate operations in oak stands

Science.gov (United States)

Henry H. Webster; John C., Jr. Meadows

1971-01-01

Economic evaluation of forest-management opportunities is a vital ingredient of effective forestry programs. Choices among management opportunities are necessary because opportunities inevitably exceed funds available, and they are important because opportunities commonly range from highly productive to decidedly unproductive. Economic evaluation in oak stands shows a...

Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

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W. J. F. Acton

2016-06-01

Full Text Available This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS together with the methods of virtual disjunct eddy covariance (using PTR-MS and eddy covariance (using PTR-ToF-MS. Isoprene was the dominant emitted compound with a mean daytime flux of 1.9 mg m−2 h−1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28-day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m−2 h−1 was calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN isoprene emission algorithms (Guenther et al., 2006. A detailed tree-species distribution map for the site enabled the leaf-level emission of isoprene and monoterpenes recorded using gas-chromatography mass spectrometry (GC–MS to be scaled up to produce a bottom-up canopy-scale flux. This was compared with the top-down canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant-species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

Comparison of Tillandsia usneoides (Spanish moss) water and leachate dynamics between urban and pristine barrier island maritime oak forests

Science.gov (United States)

Van Stan, J. T.; Stubbins, A.; Reichard, J. S.; Wright, K.; Jenkins, R. B.

2013-12-01

Epiphyte coverage on forest canopies can drastically alter the volume and chemical composition of rainwater reaching soils. Along subtropical and tropical coastlines Tillandisa usneoides L. (Spanish moss), in particular, can envelop urban and natural tree crowns. Several cities actively manage their 'moss' covered forest to enhance aesthetics in the most active tourist areas (e.g., Savannah GA, St. Augustine FL, Charleston SC). Since T. usneoides survives through atmospheric water and solute exchange from specialized trichomes (scales), we hypothesized that T. usneoides water storage dynamics and leachate chemistry may be altered by exposure to this active urban atmosphere. 30 samples of T. usneoides from managed forests around the tourist center of Savannah, Georgia, USA were collected to compare with 30 samples from the pristine maritime live oak (Quercus virginiana Mill.) forests of a nearby undeveloped barrier island (St. Catherines Island, Georgia, USA). Maximum water storage capacities were determined via submersion (for all 60 samples) along with dissolved ion (DI) and organic matter (DOM) concentrations (for 15 samples each) after simulated throughfall generation using milliQ ultrapurified water. Further, DOM quality was evaluated (for 15 samples each) using absorbance and fluorescence spectroscopy (EEMS). Results show significant alterations to water storage dynamics, DI, DOM, and DOM quality metrics under urban atmospheric conditions, suggesting modified C and water cycling in urban forest canopies that may, in turn, influence intrasystem nutrient cycles in urban catchment soils or streams via runoff.

A Social Poetics of Documentary: Grierson and the Scandinavian Documentary Tradition

DEFF Research Database (Denmark)

Bondebjerg, Ib

2014-01-01

This article deals with the influence of John Grierson on the development of the Scandinavian documentary film and television movement. Grierson's poetic for a new documentary had a strong influence on the Scandinavian documentary movement from the 1930s and on. The combination of a documentary...... format that combined a new aesthetic form with a social vision was developed in the early British class society but pointed towards a more democratic wellfare society. Key Scandinavian figures and institutions in this development of a modern, documentary movement is analysed....

Regeneration of upper-elevation red oak in the White Mountains of New Hampshire

Science.gov (United States)

William B. Leak; Mariko. Yamasaki

2013-01-01

Northern red oak occurs in limited amounts with a mixture of softwoods on the shallow soils at upper elevations in northern New England. These stands are important for wildlife habitat and forest diversity as well as a modest amount of timber harvesting. Little experience or research is available on how to regenerate upper-elevation oak. However, an examination of a 35...

Genetic evidence for a family-based Scandinavian settlement of Shetland and Orkney during the Viking periods.

Science.gov (United States)

Goodacre, S; Helgason, A; Nicholson, J; Southam, L; Ferguson, L; Hickey, E; Vega, E; Stefánsson, K; Ward, R; Sykes, B

2005-08-01

The Viking age witnessed the expansion of Scandinavian invaders across much of northwestern Europe. While Scandinavian settlements had an enduring cultural impact on North Atlantic populations, the nature and extent of their genetic legacy in places such as Shetland and Orkney is not clear. In order to explore this question further, we have made an extensive survey of both Y-chromosomal and mitochondrial DNA (mtDNA) variation in the North Atlantic region. Our findings indicate an overall Scandinavian ancestry of approximately 44% for Shetland and approximately 30% for Orkney, with approximately equal contributions from Scandinavian male and female subjects in both cases. This contrasts with the situation for the Western Isles, where the overall Scandinavian ancestry is less ( approximately 15%) and where there is a disproportionately high contribution from Scandinavian males. In line with previous studies, we find that Iceland exhibits both the greatest overall amount of Scandinavian ancestry (55%) and the greatest discrepancy between Scandinavian male and female components. Our results suggest that while areas close to Scandinavia, such as Orkney and Shetland, may have been settled primarily by Scandinavian family groups, lone Scandinavian males, who later established families with female subjects from the British Isles, may have been prominent in areas more distant from their homeland.

Effects of pedunculate oak tree vitality on gypsy moth preference and performance

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Milanović Slobodan

2014-01-01

Full Text Available Gypsy moths and powdery mildew play a significant role in oak decline processes. However, information is lacking on the effects on the gypsy moth of impaired tree vitality caused by defoliation or parasite infection. We assessed how pedunculate oak leaves collected from vigorous, declining, and infected trees influenced gypsy moth preference and performance (growth and nutritional indices. We found a negative effect of powdery mildew-infected leaves on gypsy moth performance, while declining trees had positive effects on gypsy moth performance and preference. All examined parameters of larvae fed declining oak leaves were higher than those of larvae fed vigorous oak leaves. Increased growth on declining oak leaves was caused by both higher consumption and more efficient food utilization. The results of this research could help us to better understand multitrophic interactions in complex communities such as oak forests. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

The Influence of DEM Quality on Mapping Accuracy of Coniferous- and Deciduous-Dominated Forest Using TerraSAR‑X Images

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Gerald Kändler

2012-03-01

Full Text Available Climate change is a factor that largely contributes to the increase of forest areas affected by natural damages. Therefore, the development of methodologies for forest monitoring and rapid assessment of affected areas is required. Space-borne synthetic aperture radar (SAR imagery with high resolution is now available for large-scale forest mapping and forest monitoring applications. However, a correct interpretation of SAR images requires an adequate preprocessing of the data consisting of orthorectification and radiometric calibration. The resolution and quality of the digital elevation model (DEM used as reference is crucial for this purpose. Therefore, the primary aim of this study was to analyze the influence of the DEM quality used in the preprocessing of the SAR data on the mapping accuracy of forest types. In order to examine TerraSAR-X images to map forest dominated by deciduous and coniferous trees, High Resolution SpotLight images were acquired for two study sites in southern Germany. The SAR images were preprocessed with a Shuttle Radar Topography Mission (SRTM DEM (resolution approximately 90 m, an airborne laser scanning (ALS digital terrain model (DTM (5 m resolution, and an ALS digital surface model (DSM (5 m resolution. The orthorectification of the SAR images using high resolution ALS DEMs was found to be important for the reduction of errors in pixel location and to increase the classification accuracy of forest types. SAR images preprocessed with ALS DTMs resulted in the highest classification accuracies, with kappa coefficients of 0.49 and 0.41, respectively. SAR images preprocessed with ALS DTMs resulted in greater accuracy than those preprocessed with ALS DSMs in most cases. The classification accuracy of forest types using SAR images preprocessed with the SRTM DEM was fair, with kappa coefficients of 0.23 and 0.32, respectively.Analysis of the radar backscatter indicated that sample plots dominated by coniferous trees

Nutrient cycling and nutrient losses in Andean montane forests from Antioquia, Colombia

International Nuclear Information System (INIS)

Londono Alvarez, Adriana; Montoya Gomez, Diana Cristina; Leon Pelaez, Juan Diego; Gonzalez Hernandez, Maria Isabel

2007-01-01

Gravitational flow and its chemical composition were measured in montane oak forests (Quercus humboldtii), in pine (Pinus patula) and cypress (Cupressus lusitanica) plantations in Piedras Blancas, Antioquia (Colombia), over two years. Zero tension lysimeters were used at different depth soil levels, the highest gravitational flow value at highest depth (50-80 cm) was obtained in cypress plot (492-7 mm), followed by pine (14,2 mm) and oak forest (2,0 mm). A similar behavior was encountered for nutrient losses, following the same pattern as gravitational flow. thus, for oak, pine and cypress, nutrient losses were respective/y: ca: 0,004, 0,084 and 2,270 kg ha -1 Y 1 ; P 0,008, 0,052 and 1,234 kg ha -1 Y 1 , mg: 0,004, 0,022 and 0,667 kg ha -1 y 1. K losses were 0,08 and 7,092 kg ha -1 Y 1 for oak forest and cypress plantation respectively. Nutrient losses followed the next order for each type of forest: oak: K ≥ P ≥Ca≥Mg, pine: Ca≥Fe≥P>Mg≥Zn≥Mn and cypress: K≥Mn≥Ca≥P≥Fe≥Zn≥Mg

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

Science.gov (United States)

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

1993-01-01

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

Effects of Cardinal Direction on Distribution and Populational Dynamism of Oak Leaf Roller (Tortrix viridana L. on Quercus infectoria Oliv. and Q. libani Lindl.

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mohammadreza zargaran

2018-01-01

Full Text Available Introduction Various pests attack oak trees and in most cases heavily damage them. The European oak leaf roller is one of the important oak pests in some provinces of the Zagros, and it is an important pest of oak forests in some European and North African countries, as well as in Iraq and other regions of Iran. In Iran, it is scattered in the Zagros oak forests, especially in Kohkiluyeh and Boyer Ahmad, Lorestan, Chahar Mahal and Bakhtiari, Fars, and West Azarbaijan Provinces. Repeated removal of oak leaves, particularly by herbivores such as T. viridana in spring, reduces stored photosynthates in trees leading to their decreased diametrical growth. Materials and Methods The Ghabre-Hossein region (Piranshahr was selected as the field operations region because it is one of the most important infestation centers of the European oak leaf roller in the oak forests of West-Azerbaijan. The research was carried out in two consecutive years. Samples of larval instars were taken in early May. Since the sample plot in sampling methods can be points or lines (transects, the four cardinal directions were selected in this study and transects at 100 m intervals were located in each direction.To reduce sampling error, Aleppo (Quercus infectoria and Lebanon (Q. libani oak trees were selected for measurements that were similar in appearance and almost uniform with crowns or trunks aligned along the transects. In each studied tree, four suitable branches were selected (one in each cardinal direction, and the number of larvae from the tip of each branch to a length of 50 cm inwards was counted and recorded in forms prepared beforehand. Considering studies that were carried out regarding the biology of the pest, the larvae were counted in mid-May when all larvae were in their last (fifth instar. In all, 30 Aleppo and 30 Lebanon oak trees were selected in each cardinal direction, and four branches in each direction of these trees were measured. The survey method

Removal of acorns of the alien oak Quercus rubra on the ground by scatter-hoarding animals in Belgian forests

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Merceron, NR.

2017-01-01

Full Text Available Description of the subject. Quercus rubra L. is considered an invasive species in several European countries. However, little is known about its dispersal in the introduced range. Objectives. We investigated the significance of animal dispersal of Q. rubra acorns on the ground by vertebrates in its introduced range, and identified the animal species involved. Method. During two consecutive autumns, the removal of acorns from Q. rubra and from a native oak was assessed weekly in forest sites in Belgium. We used automated detection camera traps to identify the animals that removed acorns. Results. Quercus rubra acorns were removed by wood mice (Apodemus sylvaticus L., red squirrels (Sciurus vulgaris L., rats (Rattus sp., and wild boars (Sus scrofa L.. The two former are scatter-hoarding rodents and can be considered potential dispersers. Conclusions. Dispersal of Q. rubra acorns in Western Europe by scatter-hoarding animals may help the species increasingly colonize forest ecosystems.

Chemical investigation on wood tree species in a temperate forest, east-northern Romania

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Teaca, C. A.

2007-02-01

Full Text Available A quantitative evaluation of wood chemical components for some tree species in a forest area from east-northern Romania is presented here, through a comparative study from 1964 to 2000. Investigation upon the wood tree-rings in a Quercus robur L. tree species, as a dominant species, as regards its chemical composition and structure of the natural polymer constituents - cellulose and lignin - was also performed through chemical methods to separate the main wood components, FT-IR spectroscopy, and thermogravimetry. Having in view the impact of climate and external factors (such as pollutant depositions, some possible correlations between wood chemical composition and its further use can be made. The FT-IR spectra give evidence of differences in the frequency domains of 3400-2900 cm-1 and 1730-1640 cm-1, due to some interactions between the chemical groups (OH, C=O. The crystallinity index of cellulose presents variations in the oak wood tree-rings. Thermogravimetry analyses show different behaviour of cellulose at thermal decomposition, as a function of radial growth and tree’s height. A preliminary chemical investigation of oak wood sawdust shows a relatively high content of mineral elements (ash, compared with a previous study performed in 1964, fact that may indicate an intense drying process of the oak tree, a general phenomenon present in European forests for this species.

Religion in Scandinavian Crime Fiction

DEFF Research Database (Denmark)

Hansen, Kim Toft

Scandinavian media where religion has become mediatized. Consumers of popular culture no longer endorse confidence in institutionalized religion, but that does not mean that people are losing faith: Faith only seem to adjust itself and tiptoe into popular media and popular fiction. Hence, this paper seeks...

Specific Vicariance of Two Primeval Lowland Forest Lichen Indicators

Science.gov (United States)

Kubiak, Dariusz; Osyczka, Piotr

2017-06-01

To date, the lichens Chrysothrix candelaris and Varicellaria hemisphaerica have been classified as accurate primeval lowland forest indicators. Both inhabit particularly valuable remnants of oak-hornbeam forests in Europe, but tend toward a specific kind of vicariance on a local scale. The present study was undertaken to determine habitat factors responsible for this phenomenon and verify the indicative and conservation value of these lichens. The main spatial and climatic parameters that, along with forest structure, potentially affect their distribution patterns and abundance were analysed in four complexes with typical oak-hornbeam stands in NE Poland. Fifty plots of 400 m2 each were chosen for detailed examination of stand structure and epiphytic lichens directly associated with the indicators. The study showed that the localities of the two species barely overlap within the same forest community in a relatively small geographical area. The occurrence of Chrysothrix candelaris depends basically only on microhabitat space provided by old oaks and its role as an indicator of the ecological continuity of habitat is limited. Varicellaria hemisphaerica is not tree specific but a sufficiently high moisture of habitat is essential for the species and it requires forests with high proportion of deciduous trees in a wide landscape scale. Local landscape-level habitat continuity is more important for this species than the current age of forest stand. Regardless of the indicative value, localities of both lichens within oak-hornbeam forests deserve the special protection status since they form unique assemblages of exclusive epiphytes, including those with high conservation value.

Prediction of biodiversity hotspots in the Anthropocene: The case of veteran oaks.

Science.gov (United States)

Skarpaas, Olav; Blumentrath, Stefan; Evju, Marianne; Sverdrup-Thygeson, Anne

2017-10-01

Over the past centuries, humans have transformed large parts of the biosphere, and there is a growing need to understand and predict the distribution of biodiversity hotspots influenced by the presence of humans. Our basic hypothesis is that human influence in the Anthropocene is ubiquitous, and we predict that biodiversity hot spot modeling can be improved by addressing three challenges raised by the increasing ecological influence of humans: (i) anthropogenically modified responses to individual ecological factors, (ii) fundamentally different processes and predictors in landscape types shaped by different land use histories and (iii) a multitude and complexity of natural and anthropogenic processes that may require many predictors and even multiple models in different landscape types. We modeled the occurrence of veteran oaks in Norway, and found, in accordance with our basic hypothesis and predictions, that humans influence the distribution of veteran oaks throughout its range, but in different ways in forests and open landscapes. In forests, geographical and topographic variables related to the oak niche are still important, but the occurrence of veteran oaks is shifted toward steeper slopes, where logging is difficult. In open landscapes, land cover variables are more important, and veteran oaks are more common toward the north than expected from the fundamental oak niche. In both landscape types, multiple predictor variables representing ecological and human-influenced processes were needed to build a good model, and several models performed almost equally well. Models accounting for the different anthropogenic influences on landscape structure and processes consistently performed better than models based exclusively on natural biogeographical and ecological predictors. Thus, our results for veteran oaks clearly illustrate the challenges to distribution modeling raised by the ubiquitous influence of humans, even in a moderately populated region, but also

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

Science.gov (United States)

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

2005-01-01

Little is known about biophysical controls on soil respiration in California's Sierra Nevada old-growth, mixed-conifer forests. Using portable and automated soil respiration sampling units, we measured soil respiration rate (SRR) in three dominant patch types: closed canopy (CC), ceanothus-dominated patches (CECO), and open canopy (OC). SRR varied significantly...

Mexican oaks as a potential non-timber resource for Kombucha beverages

OpenAIRE

Vázquez-Cabral, Blanca D.; Moreno-Jiménez, Martha R.; Rocha-Guzmán, Nuria E.; Gallegos-Infante, José A.; González-Herrera, Silvia M.; Gamboa-Gómez, Claudia I.; González-Laredo, Rubén F.

2016-01-01

Abstract: Oaks (Quercus spp.) are some of the world's most important and abundant trees in nearly all temperate forests of the northern hemisphere. There are two diversity centers for this genus: one is in Southeast Asia, and the other is in Mexico. Studies on the use of oak have mainly highlighted its timber applications. However, its non-timber value is still unappreciated. Ethnobotanical tradition shows infusions from Quercus leaves, alone or in combination with other plants, which have an...

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.

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

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Stephen R. Shifley

2012-08-01

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

Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

Science.gov (United States)

Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

2013-01-01

Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

Bud burst and flowering phenology in a mixed oak forest from Eastern Romania

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Ecaterina Nicoleta Chesnoiu

2009-12-01

Full Text Available Bud burst and flowering phenology have been observed in year 2008 in a natural white oak species complex situated in eastern Romania. A total of 300 mature individuals was mapped and identified based on leaf morphology. The community consists of four oak species: Quercus pedunculiflora, Q. robur, Q. pubescens and Q. petraea. A set of 28 individuals could not be unambiguously classified to one or another species. Data on bud burst showed a normal distribution and the differences among species were small. The "very late" flushing was recorded on 15th of April, three weeks later when compared to early flushing individuals. The time period between the bud burst and the complete development of leaves was nearly the same in all oak species, varying on average, between 18.4 and 20.6 days. The spatial distribution of phenological groups within the complex appears to be non-randomly, because in many parts of the study plot exist groups in which most of the trees belong to the same phenological category. Our results indicate an overlap in flowering time for all oak species which occur in the area. The data support the hypothesis that interspecific gene flow is possible between closely related oak species.

Bud burst and flowering phenology in a mixed oak forest from Eastern Romania

Directory of Open Access Journals (Sweden)

Ecaterina Nicoleta Chesnoiu

2009-11-01

Full Text Available Bud burst and flowering phenology have been observed in year 2008 ina natural white oak species complex situated in eastern Romania. A total of 300 mature individuals was mapped and identified based on leaf morphology. The community consists of four oak species: Quercus pedunculiflora, Q. robur, Q. pubescens and Q. petraea. A set of 28 individuals could not be unambiguously classified to one or another species. Data on bud burst showed a normal distribution and the differences among species were small. The "very late" flushing was recorded on 15th of April, three weeks later when compared to early flushing individuals. The time period between the bud burst and the complete development of leaves was nearly the same in all oak species, varying on average, between 18.4 and 20.6 days. The spatialdistribution of phenological groups within the complex appears to be non-randomly, because in many parts of the study plot exist groups in which most of the trees belong to the same phenological category. Our results indicate an overlap in flowering time for all oak species which occur in the area. The data support the hypothesis that interspecific gene flow is possible between closely related oak species.

The Infinitive Marker across Scandinavian

DEFF Research Database (Denmark)

Christensen, Ken Ramshøj

2007-01-01

In this paper I argue that the base-position of the infinitive marker in the Scandinavian languages and English share a common origin site. It is inserted as the top-most head in the VP-domain. The cross-linguistic variation in the syntactic distribution of the infinitive marker can be accounted...

Temporal epidemiology of sudden oak death in Oregon

Science.gov (United States)

Ebba K. Peterson; Everett M. Hansen; Alan Kanaskie

2015-01-01

An effort to eradicate Phytophthora ramorum, causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach, we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter...

A review of fire effects on bats and bat habitat in the eastern oaks region

Science.gov (United States)

Roger W. Perry

2012-01-01

Fire is increasingly being used in oak forests to promote oak regeneration, improve wildlife habitat, and reduce hazardous fuel loads. Although recent research has begun to shed light on the relationships among fire, bats, and bat habitat, these interactions are not yet fully understood. Fire may affect bats directly through heat and smoke during the burning process or...

A review of fire effects on bats and bat habitat in the eastern oak region

Science.gov (United States)

Roger W. Perry

2012-01-01

Fire is increasingly being used in oak forests to promote oak regeneration, improve wildlife habitat, and reduce hazardous fuel loads. Although recent research has begun to shed light on the relationships among fire, bats, and bat habitat, these interactions are not yet fully understood. Fire may affect bats directly through heat and smoke during the burning process or...

Oak regeneration and overstory density in the Missouri Ozarks

Science.gov (United States)

David R. Larsen; Monte A. Metzger

1997-01-01

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

Bioenergy harvest impacts to biodiversity and resilience vary across aspen-dominated forest ecosystems in the Lake States region, USA

Science.gov (United States)

Miranda T. Curzon; Anthony W. D' Amato; Brian J. Palik; Kris Verheyen

2016-01-01

Questions: Does the increase in disturbance associated with removing harvest residues negatively impact biodiversity and resilience in aspen-dominated forest ecosystems? How do responses of functional diversity measures relate to community recovery and standing biomass? Location: Aspen (Populus tremuloides, Michx.) mixedwood forests in Minnesota...

Sudden Oak Death-Induced Tanoak Mortality in Coast Redwood Forests: Current and Predicted Impacts to Stand Structure

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Kevin L. O’Hara

2010-08-01

Full Text Available Tanoak (Notholithocarpus densiflorus syn. Lithocarpus densiflorus is one of the most widespread and abundant associates of coast redwood (Sequoia sempervirens, but little is known about the structural relationships between these two species. Knowledge of such relationships is essential for a thorough understanding of the impacts of sudden oak death (caused by the exotic pathogen Phytophthora ramorum, which is currently decimating tanoak populations throughout the redwood range. In this study, we utilized a stratified plot design and a stand reconstruction technique to assess structural impacts, at present and in the future, of this emerging disease. We found that residual trees in diseased plots were more aggregated than trees in unaffected plots, and we predicted that the loss of tanoak will lead to the following short-term changes: greater average diameter, height, height-to-live-crown, and crown length, as well as an increase in average nearest neighbor differences for diameter, height, and crown length. In addition, plots lacking tanoak (living or dead—as compared to plots with tanoak—exhibited greater average diameter and increased nearest neighbor differences with regard to diameter, height, and crown length. We also conducted a preliminary exploration of how sudden oak death-induced structural changes compare with typical old-growth characteristics, and how this disease may affect the structure of old-growth forests.

Long-term trends of changes in pine and oak foliar nitrogen metabolism in response to chronic nitrogen amendments at Harvard Forest, MA.

Science.gov (United States)

Minocha, Rakesh; Turlapati, Swathi A; Long, Stephanie; McDowell, William H; Minocha, Subhash C

2015-08-01

We evaluated the long-term (1995-2008) trends in foliar and sapwood metabolism, soil solution chemistry and tree mortality rates in response to chronic nitrogen (N) additions to pine and hardwood stands at the Harvard Forest Long Term Ecological Research (LTER) site. Common stress-related metabolites like polyamines (PAs), free amino acids (AAs) and inorganic elements were analyzed for control, low N (LN, 50 kg NH4NO3 ha(-1) year(-1)) and high N (HN, 150 kg NH4NO3 ha(-1) year(-1)) treatments. In the pine stands, partitioning of excess N into foliar PAs and AAs increased with both N treatments until 2002. By 2005, several of these effects on N metabolites disappeared for HN, and by 2008 they were mostly observed for LN plot. A significant decline in foliar Ca and P was observed mostly with HN for a few years until 2005. However, sapwood data actually showed an increase in Ca, Mg and Mn and no change in PAs in the HN plot for 2008, while AAs data revealed trends that were generally similar to foliage for 2008. Concomitant with these changes, mortality data revealed a large number of dead trees in HN pine plots by 2002; the mortality rate started to decline by 2005. Oak trees in the hardwood plot did not exhibit any major changes in PAs, AAs, nutrients and mortality rate with LN treatment, indicating that oak trees were able to tolerate the yearly doses of 50 kg NH4NO3 ha(-1) year(-1). However, HN trees suffered from physiological and nutritional stress along with increased mortality in 2008. In this case also, foliar data were supported by the sapwood data. Overall, both low and high N applications resulted in greater physiological stress to the pine trees than the oaks. In general, the time course of changes in metabolic data are in agreement with the published reports on changes in soil chemistry and microbial community structure, rates of soil carbon sequestration and production of woody biomass for this chronic N study. This correspondence of selected metabolites

Optimization Forest Thinning Measures for Carbon Budget in a Mixed Pine-Oak Stand of the Qingling Mountains, China: A Case Study

Directory of Open Access Journals (Sweden)

Lin Hou

2016-11-01

Full Text Available Forest thinning is a silviculture treatment for sustainable forest management. It may promote growth of the remaining individuals by decreasing stand density, reducing competition, and increasing light and nutrient availability to increase carbon sequestration in the forest ecosystem. However, the action also increases carbon loss simultaneously by reducing carbon and other nutrient inputs as well as exacerbating soil CO2 efflux. To achieve a maximum forest carbon budget, the central composite design with two independent variables (thinning intensity and thinning residual removal rate was explored in a natural pine-oak mixed stand in the Qinling Mountains, China. The net primary productivity of living trees was estimated and soil CO2 efflux was stimulated by the Yasso07 model. Based on two years observation, the preliminary results indicated the following. Evidently chemical compounds of the litter of the tree species affected soil CO2 efflux stimulation. The thinning residual removal rate had a larger effect than thinning intensity on the net ecosystem productivity. When the selective thinning intensity and residual removal rate was 12.59% and 66.62% concurrently, the net ecosystem productivity reached its maximum 53.93 t·ha−1·year−1. The lower thinning intensity and higher thinning residual removal rated benefited the net ecosystem productivity.

Approaches to restoration of oak forests on farmed lowlands of the Mississippi river and its tributaries (Avances en la restauración de bosques de roble en tierras bajas agrícolas del Río Mississippi y sus tributaries)

Science.gov (United States)

E.S. Gardiner; D.C. Dey; John Stanturf; B.R. Lockhart

2010-01-01

The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More recently, declines in...

Standardised Testing and Assessment in Comprehensive School in Scandinavian Countries

DEFF Research Database (Denmark)

Andreasen, Karen Egedal; Eva, Hjörne,

Assessments can be considered to be an integrated part of formal educational settings, in different forms and used for different purposes. In this contribution we will discuss and analyse the use of assessments in comprehensive school in Scandinavian countries through time, as we will include....... If the comprehensive school is based on the general idea of a school for all, how can different ways of practising assessment support or work against this idea? What conclusions can be drawn from the experiences in the Scandinavian countries?...... different kinds of documentary and empirical studies in the argumentation. We will focus on which kinds of assessments has been used, for which purposes and the role of this in the perspective of society. More contemporary trends will be discussed, specially the use of standardised testing. Scandinavian...

A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing.

Science.gov (United States)

Pereira-Leal, José B; Abreu, Isabel A; Alabaça, Cláudia S; Almeida, Maria Helena; Almeida, Paulo; Almeida, Tânia; Amorim, Maria Isabel; Araújo, Susana; Azevedo, Herlânder; Badia, Aleix; Batista, Dora; Bohn, Andreas; Capote, Tiago; Carrasquinho, Isabel; Chaves, Inês; Coelho, Ana Cristina; Costa, Maria Manuela Ribeiro; Costa, Rita; Cravador, Alfredo; Egas, Conceição; Faro, Carlos; Fortes, Ana M; Fortunato, Ana S; Gaspar, Maria João; Gonçalves, Sónia; Graça, José; Horta, Marília; Inácio, Vera; Leitão, José M; Lino-Neto, Teresa; Marum, Liliana; Matos, José; Mendonça, Diogo; Miguel, Andreia; Miguel, Célia M; Morais-Cecílio, Leonor; Neves, Isabel; Nóbrega, Filomena; Oliveira, Maria Margarida; Oliveira, Rute; Pais, Maria Salomé; Paiva, Jorge A; Paulo, Octávio S; Pinheiro, Miguel; Raimundo, João A P; Ramalho, José C; Ribeiro, Ana I; Ribeiro, Teresa; Rocheta, Margarida; Rodrigues, Ana Isabel; Rodrigues, José C; Saibo, Nelson J M; Santo, Tatiana E; Santos, Ana Margarida; Sá-Pereira, Paula; Sebastiana, Mónica; Simões, Fernanda; Sobral, Rómulo S; Tavares, Rui; Teixeira, Rita; Varela, Carolina; Veloso, Maria Manuela; Ricardo, Cândido P P

2014-05-15

Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.

Diversity Management and the Scandinavian Model

DEFF Research Database (Denmark)

Romani, Laurence; Holck, Lotte; Holgersson, Charlotte

2017-01-01

This chapter presents the principal interpretations that took place in Denmark and Sweden regarding the discourse on ‘Diversity Management’. We organise our presentation around three major themes that are central to the local Scandinavian context: gender equality, migration and moral grounds. Thi...

Iowa's Forests 2008

Science.gov (United States)

Mark D. Nelson; Matt Brewer; Christopher W. Woodall; Charles H. Perry; Grant M. Domke; Ronald J. Piva; Cassandra M. Kurtz; W. Keith Moser; Tonya W. Lister; Brett J. Butler; Dacia M. Meneguzzo; Patrick D. Miles; Charles J. Barnett; Dale Gormanson

2011-01-01

The second full annual inventory of Iowa's forests (2004-2008) reports more than 3 million acres of forest land, almost all of which is timberland (98 percent), with an average volume of more than 1,000 cubic feet of growing stock per acre. American elm and eastern hophornbeam are the most numerous tree species, but silver maple and bur oak predominate in terms of...

Prevalence and causes of visual impairment and blindness among 9980 Scandinavian adults

DEFF Research Database (Denmark)

Buch, Helena; Vinding, Troels; La Cour, Morten

2004-01-01

To investigate the age-specific prevalence and causes of visual impairment and blindness in an epidemiologic study of an adult Scandinavian population.......To investigate the age-specific prevalence and causes of visual impairment and blindness in an epidemiologic study of an adult Scandinavian population....

Oak decline in the Boston Mountains, Arkansas, USA: Spatial and temporal patterns under two fire regimes

Science.gov (United States)

Martin A. Spetich; Hong S. He

2008-01-01

A spatially explicit forest succession and disturbance model is used to delineate the extent and dispersion of oak decline under two fire regimes over a 150-year period. The objectives of this study are to delineate potential current and future oak decline areas using species composition and age structure data in combination with ecological land types, and to...

The origin of Ceratocystis fagacearum, the oak wilt fungus

Science.gov (United States)

Jennifer Juzwik; Thomas C. Harrington; William L. MacDonald; David N. Appel

2008-01-01

The oak wilt pathogen, Ceratocystis fagacearum, may be another example of a damaging, exotic species in forest ecosystems in the United States. Though C. fagacearum has received much research attention, the origin of the fungus is unknown. The pathogen may have been endemic at a low incidence until increased disturbances, changes...

Three new species of the genus Trachelas (Araneae: Trachelidae) from an oak forest inside the Mesoamerican biodiversity hotspot in Mexico.

Science.gov (United States)

Rivera-Quiroz, F Andrés; Alvarez-Padilla, Fernando

2015-08-07

Three new species of the spider genus Trachelas L. Koch, 1872 are described and included in the speciosus group based on the following features: embolus as a separate sclerite from the tegulum with no basal coils, legs with a conspicuous fringe of long trichobothria and narrow copulatory ducts coiled irregularly. The new species described are: T. crassus sp. n., T. ductonuda sp. n. and T. odoreus sp. n. A total of 46 specimens were collected in an oak forest near Pico de Orizaba Volcano, Mexico. Most individuals were collected on low vegetation using beating trays and direct collecting at night. Additional images are available at www.unamfcaracnolab.com.

Word-wide meta-analysis of Quercus forests ectomycorrhizal fungal diversity reveals southwestern Mexico as a hotspot.

Science.gov (United States)

García-Guzmán, Olimpia Mariana; Garibay-Orijel, Roberto; Hernández, Edith; Arellano-Torres, Elsa; Oyama, Ken

2017-11-01

Quercus is the most diverse genus of ectomycorrhizal (ECM) host plants; it is distributed in the Northern and Southern Hemispheres, from temperate to tropical regions. However, their ECM communities have been scarcely studied in comparison to those of conifers. The objectives of this study were to determine the richness of ECM fungi associated with oak forests in the Cuitzeo basin in southwestern Mexico; and to determine the level of richness, potential endemism and species similarity among ECM fungal communities associated with natural oak forests worldwide through a meta-analysis. The ITS DNA sequences of ECM root tips from 14 studies were included in the meta-analysis. In total, 1065 species of ECM fungi have been documented worldwide; however, 812 species have been only found at one site. Oak forests in Europe contain 416 species, Mexico 307, USA 285, and China 151. Species with wider distributions are Sebacinaceae sp. SH197130, Amanita subjunquillea, Cenococcum geophilum, Cortinarius decipiens, Russula hortensis, R. risigallina, R. subrubescens, Sebacinaceae sp. SH214607, Tomentella ferruginea, and T. lapida. The meta-analysis revealed (1) that Mexico is not only a hotspot for oak species but also for their ECM mycobionts. (2) There is a particularly high diversity of ECM Pezizales in oak seasonal forests from western USA to southwestern Mexico. (3) The oak forests in southwestern Mexico have the largest number of potential endemic species. (4) Globally, there is a high turnover of ECM fungal species associated with oaks, which indicates high levels of alpha and beta diversity in these communities.

Attack pattern of Platypus koryoensis (Coleoptera: Curculionidae: Platypodidae) in relation to crown dieback of Mongolian oak in Korea

Science.gov (United States)

Jung-Su Lee; Robert A. Haack; Won Il. Choi

2011-01-01

The ambrosia beetle, Platypus koryoensis (Murayama), vectors the Korean oak wilt (KOW) pathogen, Raffaelea quercus-mongolicae K.H. Kim, Y.J. Choi, & H.D. Shin, in Korea, which is highly lethal to Mongolian oak, Quercus mongolica Fisch., and is considered a major threat to forest ecosystem health. We...

Scandinavian neuroscience during the Nazi era

DEFF Research Database (Denmark)

Kondziella, Daniel; Hansen, Klaus; Zeidman, Lawrence A

2013-01-01

Although Scandinavian neuroscience has a proud history, its status during the Nazi era has been overlooked. In fact, prominent neuroscientists in German-occupied Denmark and Norway, as well as in neutral Sweden, were directly affected. Mogens Fog, Poul Thygesen (Denmark) and Haakon Sæthre (Norway...

Viñales Taxonomic Characterization and trophic groups of two communities of birds associated to semideciduos forests and vegetation of Pine-oak of the paths «Marvels of Viñales» and «Valley Ancón» in Viñales National Park

Directory of Open Access Journals (Sweden)

Miguel Cué Rivero

2015-06-01

Full Text Available The present work was carried out in the months of February to April 2009 in the semideciduos forest «Marvels of Viñales» and the formation pine-encino of the «Valley Ancón» of the Viñales National Park and it pursued as main objective to characterize the taxonomic composition and tropic groups tof two communities of birds associated to semideciduos forest and pine oak vegetation from both -. The method of circular parcels of fixed radio was used in 30 points of counts separated to 150 m one of another. There were detected a total of 44 species of birds (in the semideciduo and 42 in pine-oak contained in 9 orders and 18 families. They registered 23 trophic groups with prevalence of Insectivorous. The communities of birds of the formation of semideciduo forest of the path «Marvels of Viñales» and of the forest of pine oak of «Valley Ancón» presented differences in its taxonomic composition The communities of birds of both vegetable formations showed differences as for their trophiccomposition but so much in one as in other majority of birds consumers of insects and grains was observed.

Indirect effects of rodents on arthropods in a Scandinavian boreal forest

OpenAIRE

Malá, Barbora

2016-01-01

Rodents in boreal forest are an important component of food webs. Their role as drivers of the boreal forest ecosystem is debated. As herbivores they affect plant communities and alter qualities of plants. Consequently availability of food resources for other herbivorous species is altered. In my thesis I studied whether rodents indirectly influence communities of arthropods via plant resources. It is assumed that phytophagous arthropods respond to changes in plant resources by different feed...

Forest response and recovery following disturbance in upland forests of the Atlantic Coastal Plain.

Science.gov (United States)

Schäfer, Karina V R; Renninger, Heidi J; Carlo, Nicholas J; Vanderklein, Dirk W

2014-01-01

Carbon and water cycling of forests contribute significantly to the Earth's overall biogeochemical cycling and may be affected by disturbance and climate change. As a larger body of research becomes available about leaf-level, ecosystem and regional scale effects of disturbances on forest ecosystems, a more mechanistic understanding is developing which can improve modeling efforts. Here, we summarize some of the major effects of physical and biogenic disturbances, such as drought, prescribed fire, and insect defoliation, on leaf and ecosystem-scale physiological responses as well as impacts on carbon and water cycling in an Atlantic Coastal Plain upland oak/pine and upland pine forest. During drought, stomatal conductance and canopy stomatal conductance were reduced, however, defoliation increased conductance on both leaf-level and canopy scale. Furthermore, after prescribed fire, leaf-level stomatal conductance was unchanged for pines but decreased for oaks, while canopy stomatal conductance decreased temporarily, but then rebounded the following growing season, thus exhibiting transient responses. This study suggests that forest response to disturbance varies from the leaf to ecosystem level as well as species level and thus, these differential responses interplay to determine the fate of forest structure and functioning post disturbance.

The Scandinavian baltic pancreatic club (SBPC) database

DEFF Research Database (Denmark)

Olesen, Søren S; Poulsen, Jakob Lykke; Drewes, Asbjørn M

2017-01-01

OBJECTIVES: Chronic pancreatitis (CP) is a multifaceted disease associated with several risk factors and a complex clinical presentation. We established the Scandinavian Baltic Pancreatic Club (SBPC) Database to characterise and study the natural history of CP in a Northern European cohort. Here......, we describe the design of the database and characteristics of the study cohort. METHODS: Nine centres from six different countries in the Scandinavian-Baltic region joined the database. Patients with definitive or probable CP (M-ANNHEIM diagnostic criteria) were included. Standardised case report...... forms were used to collect several assessment variables including disease aetiology, duration of CP, preceding acute pancreatitis, as well as symptoms, complications, and treatments. The clinical stage of CP was characterised according to M-ANNNHEIM. Yearly follow-up is planned for all patients. RESULTS...

Carbon sequestration in the New Jersey Pine Barrens under different scenarios of fire management

Science.gov (United States)

Robert M. Scheller; Steve Van Tuyl; Kenneth L. Clark; John Hom; Inga. La Puma

2011-01-01

The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented and subject to frequent disturbance and forest management. Over long time periods (>50 years), the balance between oak...

[Biogeochemical cycles in natural forest and conifer plantations in the high mountains of Colombia].

Science.gov (United States)

León, Juan Diego; González, María Isabel; Gallardo, Juan Fernando

2011-12-01

Plant litter production and decomposition are two important processes in forest ecosystems, since they provide the main organic matter input to soil and regulate nutrient cycling. With the aim to study these processes, litterfall, standing litter and nutrient return were studied for three years in an oak forest (Quercus humboldtii), pine (Pinus patula) and cypress (Cupressus lusitanica) plantations, located in highlands of the Central Cordillera of Colombia. Evaluation methods included: fine litter collection at fortnightly intervals using litter traps; the litter layer samples at the end of each sampling year and chemical analyses of both litterfall and standing litter. Fine litter fall observed was similar in oak forest (7.5 Mg ha/y) and in pine (7.8 Mg ha/y), but very low in cypress (3.5 Mg ha/y). Litter standing was 1.76, 1.73 and 1.3 Mg ha/y in oak, pine and cypress, respectively. The mean residence time of the standing litter was of 3.3 years for cypress, 2.1 years for pine and 1.8 years for oak forests. In contrast, the total amount of retained elements (N, P, S, Ca, Mg, K, Cu, Fe, Mn and Zn) in the standing litter was higher in pine (115 kg/ha), followed by oak (78 kg/ha) and cypress (24 kg/ha). Oak forests showed the lowest mean residence time of nutrients and the highest nutrients return to the soil as a consequence of a faster decomposition. Thus, a higher nutrient supply to soils from oaks than from tree plantations, seems to be an ecological advantage for recovering and maintaining the main ecosystem functioning features, which needs to be taken into account in restoration programs in this highly degraded Andean mountains.

Growth-Climate Response of Young Turkey Oak (Quercus cerris L. Coppice Forest Stands along Longitudinal Gradient in Albania

Directory of Open Access Journals (Sweden)

Merita Stafasani

2015-06-01

Full Text Available Background and Purpose: Turkey oak (Quercus cerris L. is the most widespread species in Albania and less investigated from dendroclimatological point of view. Previous studies have reported that Q. cerris is sensitive to the environment when growing at different latitudes and ecological conditions. Based on this fact we have explored the response of different Q. cerris populations located along the longitudinal gradient. Materials and Methods: The stem discs were sampled from six sites (Kukes, Diber, Rreshen, Ulez, Elbasan, Belsh along longitudinal gradient ranging from north-east to central Albania. All oak forests stands grow under the influence of specific local Mediterranean climate. Tree-ring widths were measured to the nearest 0.001 mm using a linear table, LINTAB and the TSAP-Win program. Following the standard dendrochronological procedures residual tree-ring width chronologies were built for each site. Statistical parameters commonly used in dendrochronology were calculated for each site chronology. Relations between the tree-ring chronologies were explored using Hierarchical Factor Classification (HFC and Principal Component Analysis (PCA, while the radial growth-climate relationship was analyzed through correlation analysis using a 19-month window from April in the year prior to tree-ring formation (year t - 1 until October in the year of growth (year t. Results and Conclusions: The length of the site chronologies ranged from 16 to 36 years, with the Elbasan site chronology being the longest and the Belsh site chronology the shortest one. Trees at lower elevation were younger than trees at higher elevation. Statistical parameters (mean sensitivity (MS and auto correlation (AC of site chronologies were different among them and lower values of AC1 showed a weaker dependence of radial growth from climatic conditions of the previous growing year. Principal component analysis showed that Belsh, Rreshen and Elbasan site chronologies were

Scandinavian women's experiences in connection with "abortion on request": a systematic review protocol

DEFF Research Database (Denmark)

Petersen, Mille Nyboe; Fandt Hansen, Christl

2014-01-01

The objective of this review is to investigate Scandinavian women’s experiences in connection with "abortion on request”. Types of participants: This review will consider studies that include adult women from age 18 living in (but not necessarily legal citizens of) Scandinavia, defined as Denmark...... and after the intervention - an abortion on request and in investigating possible and self-reported psychosocial or psychological health consequences following the abortion. Types of context: This review will focus on Scandinavian women who have had a legal abortion on request in a Scandinavian hospital......, Sweden and Norway, who have experienced an induced (medical or surgical) abortion without a medical reason, described here as an “abortion on request”. Phenomena of interest: The objective of this review is to investigate Scandinavian women’s experiences in connection with – meaning before, during...

The Puzzle of the Scandinavian Welfare State and Social Trust

DEFF Research Database (Denmark)

Svendsen, Gunnar Lind Haase; Svendsen, Gert Tinggaard

2015-01-01

The Scandinavian welfare model is a puzzle to economists: It works economically, even though free-riding should prevail with its explosive cocktail of high taxation and high social benefits. One overlooked solution to the puzzle could be the unique stock of social trust present in Scandinavia. Here......, the four Scandinavian countries (Norway, Denmark, Sweden, and Finland) form the top three with scores above 60 percent social trust on a ranking that covers 94 countries from all over the world....

Assemblages of saproxylic beetles on large downed trunks of oak.

Science.gov (United States)

Milberg, Per; Bergman, Karl-Olof; Sancak, Kerem; Jansson, Nicklas

2016-03-01

Old living oaks (Quercus robur) are known as a very species-rich habitat for saproxylic beetles, but it is less clear to what extent such veteran trees differ from an even rarer feature: downed trunks of large oaks. In this study, we set out to sample this habitat, using window traps, with two aims: (1) to describe the variation of assemblages among downed trunks of different type and (2) to compare beetles on downed oaks with data from veteran standing trees. The results showed that trunk volume and sun exposure better explained assemblages as well as species numbers on downed trunks than did decay stage. Furthermore, species classified as facultative saproxylic species showed weak or no differentiation among downed trunks. Species with different feeding habits showed no apparent differentiation among downed trunks. Furthermore, species composition on dead, downed oak trunks differed sharply from that of living, veteran oaks. Wood or bark feeders were more common on veterans than downed trunks, but there was no difference for those species feeding on fungi or those feeding on insects and their remains. In conclusion, for a successful conservation of the saproxylic beetle fauna it is important to keep downed oak trunks, and particularly large ones, in forest and pastures as they constitute a saproxylic habitat that differs from that of living trees.

[Madison School Forests Ecology Series.

Science.gov (United States)

Madison Public Schools, WI.

Each of these three booklets is to be used in conjunction with a field trip in the Madison, Wisconsin area, and to serve as a guide for presenting the filmstrips for each excursion. "Madison School Forests" emphasizes plant succession in a natural oak community. "Three Layers of Green in the Madison School Forest" emphasizes…

Direct Seeding Scarlet Oak in the North Carolina Mountains

Science.gov (United States)

Earl R. Sluder

1965-01-01

Seedling establishment rates varied from 0 to 50 percent in a direct seeding study with scarlet oak (Quercus coccinea Muenchh.) on the Bent Creek Experimental Forest near Asheville, North Carolina. Acorns planted 2 inches deep in the spring with screen protection produced the most seedlings; those surface sown without screens in the spring or fall...

Late Quaternary developments of Mediterranean oaks in the Atlantic domain of the Iberian Peninsula: The case of the Cantabrian region (N Spain)

Science.gov (United States)

Uzquiano, P.; Ruiz-Zapata, MaB.; Gil-Garcia, MaJ.; Fernández, S.; Carrión, J. S.

2016-12-01

A synthesis of the occurrence of the evergreen oak (Quercus ilex-type) in the Cantabrian region (northern Spain) is presented on the basis of integrated charcoal and pollen analyses. Archaeological charcoal comes largely from sites along the littoral and pre-littoral territories of the Basque Country, Cantabria and Asturias dated from 45 to 3.7 Kyr cal BP, and culturally ranging from Mousterian to Iron Age. Pollen information is produced from a few archaeological sites but mainly from peats and lake sediments. Q. ilex-type is observed as early as at 45-30 Kyr cal BP, with sporadic occurrences in vegetation contexts dominated by Pinus sylvestris-type, which was widely exploited by Mousterian and Aurignacian inhabitants. Afterwards, during the Upper Palaeolithic, there is an important decline, and Q. ilex-type is hardly present between 29 and 15 Kyr cal BP, with open environments dominated by heathland shrubs. From Late Magdalenian onwards, Q. ilex-type expanded again, remaining in the landscape of the Cantabrian region throughout the Holocene, although subordinated in deciduous oak forests under the influence of oceanic climate conditions. Q. ilex-type had a more favourable position than deciduous Quercus across the Cantabrian southern slopes and northwest of the adjacent Iberian Cordillera, where oceanic influences have become attenuated by summer drought and continentality.

Habitat Fragmentation can Modulate Drought Effects on the Plant-soil-microbial System in Mediterranean Holm Oak (Quercus ilex) Forests.

Science.gov (United States)

Flores-Rentería, Dulce; Curiel Yuste, Jorge; Rincón, Ana; Brearley, Francis Q; García-Gil, Juan Carlos; Valladares, Fernando

2015-05-01

Ecological transformations derived from habitat fragmentation have led to increased threats to above-ground biodiversity. However, the impacts of forest fragmentation on soils and their microbial communities are not well understood. We examined the effects of contrasting fragment sizes on the structure and functioning of soil microbial communities from holm oak forest patches in two bioclimatically different regions of Spain. We used a microcosm approach to simulate the annual summer drought cycle and first autumn rainfall (rewetting), evaluating the functional response of a plant-soil-microbial system. Forest fragment size had a significant effect on physicochemical characteristics and microbial functioning of soils, although the diversity and structure of microbial communities were not affected. The response of our plant-soil-microbial systems to drought was strongly modulated by the bioclimatic conditions and the fragment size from where the soils were obtained. Decreasing fragment size modulated the effects of drought by improving local environmental conditions with higher water and nutrient availability. However, this modulation was stronger for plant-soil-microbial systems built with soils from the northern region (colder and wetter) than for those built with soils from the southern region (warmer and drier) suggesting that the responsiveness of the soil-plant-microbial system to habitat fragmentation was strongly dependent on both the physicochemical characteristics of soils and the historical adaptation of soil microbial communities to specific bioclimatic conditions. This interaction challenges our understanding of future global change scenarios in Mediterranean ecosystems involving drier conditions and increased frequency of forest fragmentation.

Epiphytic lichens as sentinels for heavy metal pollution at forest ecosystems (central Italy)

International Nuclear Information System (INIS)

Loppi, Stefano; Pirintsos, S.A.

2003-01-01

Epiphytic lichens were useful as an early warning system for changes in forest ecosystems. - The results of a study using epiphytic lichens (Parmelia caperata) as sentinels for heavy metal deposition at six selected forest ecosystems of central Italy are reported. The woods investigated are characterized by holm oak (Quercus ilex), turkey oak (Quercus cerris) and beech (Fagus sylvatica) and represent the typical forest ecosystems of central Italy at low, medium and high elevations, respectively. The results showed that levels of heavy metals in lichens were relatively low and consequently no risk of heavy metal air pollution is expected for the six forest ecosystems investigated. However, for two of them there are indications of a potential risk: the beech forest of Vallombrosa showed signs of contamination by Pb as a consequence of vehicle traffic due to the rather high touristic pressure in the area, and the holm oak forest of Cala Violina showed transboundary pollution by Mn, Cr and Ni originating from the steel industry in Piombino. Epiphytic lichens proved to be very effective as an early warning system to detect signs of a changing environment at forest ecosystems

Elephant distribution around a volcanic shield dominated by a mosaic of forest and savanna (Marsabit, Kenya)

NARCIS (Netherlands)

Ngene, S.M.; Skidmore, A.K.; Gils, H.; Douglas-Hamilton, I.; Omondi, P.

2009-01-01

We investigated the factors that influenced the distribution of the African elephant around a volcanic shield dominated by a mosaic of forest and savanna in northern Kenya. Data on elephant distribution were acquired from four female and five bull elephants, collared with satellite-linked

Coevolution of floodplain and riparian forest dynamics on large, meandering rivers

Science.gov (United States)

Stella, J. C.; Riddle, J. D.; Battles, J. J.

2012-12-01

On large meandering rivers, riparian forests coevolve with the floodplains that support them. Floodplain characteristics such as local disturbance regime, deposition rates and sediment texture drive plant community dynamics, which in turn feed back to the abiotic processes. We investigated floodplain and riparian forest coevolution along the along the Sacramento River (California, USA), a large, mediterranean-climate river that has been extensively regulated for 70 years, but whose 160-km middle reach (Red Bluff to Colusa) retains some channel mobility and natural forest stands. Guided by maps of floodplain change over time and current vegetation cover, we conducted an extensive forest inventory and chronosequence analysis to quantify how abiotic conditions and forest structural characteristics such as tree density, basal area and biomass vary with floodplain age. We inventoried 285 fixed-area plots distributed across 19 large point bars within vegetation patches ranging in age from 4 to 107 years. Two successional trajectories were evident: (1) shifting species dominance over time within forested areas, from willow to cottonwood to walnut, boxelder and valley oak; and (2) patches of shrub willow (primarily Salix exigua) that maintained dominance throughout time. Sediment accretion was reduced in the persistent willow plots compared to the successional forest stands, suggesting an association between higher flood energy and arrested succession. Forested stands 40-60 years old were the most extensive across the chronosequence in terms of floodplain area, and supported the highest biomass, species diversity, and functional wildlife habitat. These stands were dominated by Fremont cottonwood (Populus fremontii) and reached their maxima in terms of tree size and biomass at age 50 years. The persistent willow stands reached their structural maxima earlier (32 years) and supported lower biomass. Basal area and abundance of large trees decreased in stands >90 years old

Biodiversity conservation in the face of dramatic forest disease: an integrated conservation strategy for tanoak (Notholithocarpus densiflorus) threatened by sudden oak death

Science.gov (United States)

Richard C. Cobb; David M. Rizzo; Katherine J. Hayden; Matteo Garbelotto; A.N. Filipe João; Christopher A. Gilligan; Whalen W. Dillon; Ross K. Meentemeyer; Yana S. Vlachovic; Ellen Goheen; Tedmund J. Swiecki; Everett M. Hansen; Susan J. Frankel

2013-01-01

Non-native diseases of dominant tree species have diminished North American forest biodiversity, structure, and ecosystem function over the last 150 years. Since the mid-1990s, coastal California forests have suffered extensive decline of the endemic overstory tree tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh...

Leaf gas exchange of mature bottomland oak trees

Science.gov (United States)

Rico M. Gazal; Mark E. Kubiske; Kristina F. Connor

2009-01-01

We determined how changes in environmental moisture affected leaf gas exchange in Nuttall (Quercus texana Buckley), overcup (Q. lyrata Walt.), and dominant and codominant swamp chestnut (Q. michauxii Nutt.) oak trees in Mississippi and Louisiana. We used canopy access towers to measure leaf level gas...

Linking sudden oak death with spatial economic value transfer

Science.gov (United States)

Tom Holmes; Bill Smith

2008-01-01

Sudden oak death (caused by Phytophthora ramorum) is currently having a dramatic impact on the flow of ecosystem services provided by trees and forests in California. Timber species in California are not thought to be at risk of mortality from this pathogen and, consequently, economic impacts accrue to non-market values of trees such as aesthetics,...

A Scandinavian Model of Innovative Product Development

DEFF Research Database (Denmark)

McAloone, Timothy Charles; Andreasen, Mogens Myrup; Boelskifte, Per

2007-01-01

The educational systems in the small Scandinavian countries are open to experiments and new education programmes. This paper presents such an initiative from Denmark, showing new interpretations of industrial needs, research insights, educational ideas and identification of core innovative compet...

The Effects of Intermittent Flooding on Seedlings of Three Forest Species

Science.gov (United States)

P.H. Anderson; S.R. Pezeshki

1999-01-01

Under greenhouse conditions, seedlings of three forest species, baldcypress (Taxodium distichum), nuttall oak (Quercus nuttallii), and swamp chestnut oak (Quercus michauxii) were subjected to an intermittent flooding and subsequent physiological and growth responses to such conditions were evaluated....

Action research: Scandinavian Experiences

DEFF Research Database (Denmark)

Rasmussen, Lauge Baungaard

2004-01-01

The article focus on paradigms, methods and ethics of action research in the Scandinavian countries. The special features of the action research paradigm is identified. A historical overview follows of some main action research projects in Norway, Sweden and Denmark. The tendency towards upsclae...... action research projects from organisational or small community projects yo large-scale, regional based network apporaches are also outlined and discussed. Finally, a synthesised approach of the classical, socio-technical action research approach and the large-scale network and holistic approaches...

The impact of Zero Energy Buildings on the Scandinavian energy system

International Nuclear Information System (INIS)

Seljom, Pernille; Lindberg, Karen Byskov; Tomasgard, Asgeir; Doorman, Gerard; Sartori, Igor

2017-01-01

This paper investigates how an extensive implementation of net Zero Energy Buildings (ZEBs) affects cost-optimal investments in the Scandinavian energy system towards 2050. Analyses are done by a stochastic TIMES model with an explicit representation of the short-term uncertainty related to electricity supply and heat demand in buildings. We define a nearly ZEB to be a highly efficient building with on-site PV production. To evaluate the flexibility requirement of the surrounding energy system, we consider no use of energy storage within the ZEBs. The results show that ZEBs reduce the investments in non-flexible hydropower, wind power and Combined Heat and Power, and increase the use of direct electric heating and electric boilers. With building integrated PV production of 53 TWh in 2050, ZEBs increase the Scandinavian electricity generation by 16 TWh and increase the net electricity export by 19 TWh. Although the increased production reduces the electricity prices, the low heat demand in ZEBs gives a drop in the electricity consumption by 4 TWh in 2050. Finally, the results demonstrate that the Scandinavian energy system is capable of integrating a large amount of ZEBs with intermittent PV production due to the flexible hydropower in Norway and Sweden. - Highlights: • We analyse cost-optimal integration of ZEBs in the Scandinavian energy system. • We capture impact of short-term uncertainty on long-term investment decisions. • ZEBs reduce the investments in the electricity and heating sector. • The Scandinavian electricity sector is capable of integrating ZEBs with PV. • The operation of the flexible hydropower is changed with ZEBs.

Ecological recovery of affected areas by a forest fire in the Tintales watershed (Boyacá, Colombia

Directory of Open Access Journals (Sweden)

Fernando Fernández-Méndez

2016-07-01

Full Text Available The tintales watershed, located in the Santuario de Flora y Fauna (SFF of Iguaque, Boyaca, was affected by a wildfire. In that area, the natural regeneration was evaluated in 29 permanent plots. Two phyto-physiognomies, a rocky outcrop and oak were evaluated to compare their richness, diversity and dominance, with rocky outcrop yielding a greater richness and diversity. The Asteraceae family was the one that obtained greater representation, with a dominance of species such as Hypoxis decumbens, Pterídium aquilinum and Andropogon bicornis. The diversity in the whole sampling was low and uniform due to the repeated incidence of forest fires that have caused changes in the structure and composition of vegetation. The vegetation found did not differ substantially from other studies reported for this life zone and the region, where the dynamics of land use are similar, with high deforestation and fires. The vegetation established after the fire is dominated by colonizing and pioneering species. In the two phyto physiognomies studied after a year of the fire, two plant communities with statistically significant differences in wealth and homogeneity could be stablished. To start the restoration process, it is recommended to use as one of the inputs, the taxonomic differences found between oak  and rocky outcrop.

Chloroplast DNA footprints of postglacial recolonization by oaks

Science.gov (United States)

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

1997-01-01

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

Relative importance of various regeneration mechanisms in different restoration stages of Quercus variabilis forest after selective logging

Directory of Open Access Journals (Sweden)

Yaoqin Xue

2014-08-01

Full Text Available Aim of study: Quercus variabilis (Chinese cork oak reproduces asexually and sexually. This study aimed to determine the status and growth of asexual and sexual recruits of Q. variabilis in different forest recovery stages.Area of study: Three selective logged stands and one unlogged stand in Q. variabilis forest, Shaanxi Province, China.Material and Methods: Origin, number, basal diameter, height and size structure of Q. variabilis shoots (height ≤200 cm were investigated in the plots of 5, 10, and 20-years post-logging stands and unlogged stand. Effects of recovery stage on the density and growth of the three original recruits (stump sprouts, stem base sprouts and true seedlings were analysis by One-way ANOVA.Main results: Sprouts dominated logged stands, whereas true seedlings dominated unlogged stand, stem base sprouts only existed in 20-years post-logging and unlogged stands. Stump sprout density and sprout number per stump both declined with extended post-logging time. True seedlings density increased from 7 to 20 shoots/100 m2 as the postlogging time extended, and peaked in unlogged stand (94 shoots/100 m2. An ongoing size structure was observed in true seedlings in all stands. Stump sprouts were taller and greater than true seedlings.Research highlights: Stump sprouts contributed more to Q. variabilis forest recovery in the early stage after disturbance. The contribution of true seedlings was limited in the same stage, but they were beneficial for population long-term development. Stem base sprouts were most likely to be a survival strategy rather than a reproductive strategy.Key words: asexual reproduction; true seedling; post-logging time; Chinese cork oak.

Patterns of forest use and endemism in resident bird communities of north-central Michoacan, Mexico

Science.gov (United States)

Santiago Garcia; Deborah M. Finch; Gilberto Chavez. Leon

1998-01-01

We compared breeding avian communities among 11 habitat types in north-central Michoacan, Mexico, to determine patterns of forest use by endemic and nonendemic resident species. Point counts of birds and vegetation measurements were conducted at 124 sampling localities from May through July, in 1994 and 1995. Six native forest types sampled were pine, pine-oak, oak-...

Shifting Authenticities in Scandinavian Music Education

Science.gov (United States)

Dyndahl, Petter; Nielsen, Siw Graabraek

2014-01-01

There has been an ongoing tendency, taking place in the Scandinavian countries from the late 1970s onwards, to expand the repertoires and resources of music as an educational matter, an academic field, as well as an area for support and funding from cultural authorities, organisations and institutions. Here, popular music, jazz, folk music and…

Nearshoring Practices of Scandinavian MNCs in Central and Eastern Europe

DEFF Research Database (Denmark)

Slepniov, Dmitrij; Brazinskas, Sigitas; Wæhrens, Brian Vejrum

2012-01-01

The principal objective of this paper is to unravel and assess current nearshoring practices of Scandinavian MNCs. In addressing this issue, we draw on the literature within the areas of offshoring and outsourcing. We use mixed methods of enquiry involving case studies, survey techniques as well...... as secondary statistical data. To provide a more refined view on the practices and processes of nearshoring, we complement the case studies of Scandinavian manufacturers with a survey of 55 Lithuanian vendor companies and other statistical data. The paper outlines the main drivers of nearshoring...

Paleovegetation reconstruction of fossil forests dominated by Metasequoia and Glyptostrobus from the late Pliocene Kobiwako Group, central Japan

OpenAIRE

CHIYOMI, YAMAKAWA; ARATA, MOMOHARA; TOMOO, NUNOTANI; MIDORI, MATSUMOTO; YASUYUKI, WATANO; Lake Biwa Museum; Graduate School of Horticulture, Chiba University; Lake Biwa Museum; Graduate School of Science, Chiba University; Graduate School of Science, Chiba University

2008-01-01

A late Pliocene (1.8-1.9 Ma) wetland fossil forest community that was dominated by Metasequoia and Glyptostrobus was reconstructed based on the species composition of the stumps and other plant macrofossil assemblages. The plant fossils were recovered from a fossil forest preserved in deposits of the Kobiwako Group that are exposed in the Echi River, Shiga Prefecture, central Japan. Fossil wood of Metasequoia and Glyptostrobus was distinguished based on anatomical characteristics. Apportionme...

Self-thinning dynamics in cork oak woodlands: providing a baseline for managing density

International Nuclear Information System (INIS)

Fonseca, T.; Monteiro, L.; Enes, T.; Cerveira, A.

2017-01-01

Aim of study: The study aims to evaluate the maximum potential stocking level in cork oak (Quercus suber L.) woodlands, using the ecologically-based size-density relationship of the self-thinning law. Area of study: The study area refers to cork oak forests in mainland Portugal, distributed along its 18 districts from north to south. Material and Methods: A dataset with a total of 2181 observations regarding pure cork oak stands was collected from the Portuguese Forest Inventory (NFI) databases and from research plots. The dataset was subjected to two filtering procedures, one more restrictive than the other, to select the stands presenting the higher stocking values. The two resulting subsets, with 116 and 36 observations, from 16 and 10 districts of mainland Portugal, respectively, were then used to assess and describe the allometric relationship between tree number and their mean diameter. Main results: The allometric relationship was analysed and modelled using the log transformed variables. A slightly curvilinear trend was identified. Thus, a straight line and a curve were both fitted for comparison purposes. Goodness-of-fit statistics point out for a good performance when the data is set to the uppermost observed stocking values. A self-thinning line for cork oak was projected from the estimated relationship. Research highlights: The self-thinning model can be used as an ecological approach to develop density guidelines for oak woodlands in a scenario of increasing cork demands. The results indicate that the recommendations being applied in Portugal are far below the maximal potential stocking values for the species. It is therefore of the utmost importance to review the traditional silvicultural guidelines and endorse new ones.

Self-thinning dynamics in cork oak woodlands: providing a baseline for managing density

Energy Technology Data Exchange (ETDEWEB)

Fonseca, T.; Monteiro, L.; Enes, T.; Cerveira, A.

2017-11-01

Aim of study: The study aims to evaluate the maximum potential stocking level in cork oak (Quercus suber L.) woodlands, using the ecologically-based size-density relationship of the self-thinning law. Area of study: The study area refers to cork oak forests in mainland Portugal, distributed along its 18 districts from north to south. Material and Methods: A dataset with a total of 2181 observations regarding pure cork oak stands was collected from the Portuguese Forest Inventory (NFI) databases and from research plots. The dataset was subjected to two filtering procedures, one more restrictive than the other, to select the stands presenting the higher stocking values. The two resulting subsets, with 116 and 36 observations, from 16 and 10 districts of mainland Portugal, respectively, were then used to assess and describe the allometric relationship between tree number and their mean diameter. Main results: The allometric relationship was analysed and modelled using the log transformed variables. A slightly curvilinear trend was identified. Thus, a straight line and a curve were both fitted for comparison purposes. Goodness-of-fit statistics point out for a good performance when the data is set to the uppermost observed stocking values. A self-thinning line for cork oak was projected from the estimated relationship. Research highlights: The self-thinning model can be used as an ecological approach to develop density guidelines for oak woodlands in a scenario of increasing cork demands. The results indicate that the recommendations being applied in Portugal are far below the maximal potential stocking values for the species. It is therefore of the utmost importance to review the traditional silvicultural guidelines and endorse new ones.

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

Science.gov (United States)

A. Paige Fischer; John C. Bliss

2009-01-01

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

Bamboo-dominated forests of the southwest Amazon: detection, spatial extent, life cycle length and flowering waves.

Directory of Open Access Journals (Sweden)

Anelena L de Carvalho

Full Text Available We map the extent, infer the life-cycle length and describe spatial and temporal patterns of flowering of sarmentose bamboos (Guadua spp in upland forests of the southwest Amazon. We first examine the spectra and the spectral separation of forests with different bamboo life stages. False-color composites from orbital sensors going back to 1975 are capable of distinguishing life stages. These woody bamboos flower produce massive quantities of seeds and then die. Life stage is synchronized, forming a single cohort within each population. Bamboo dominates at least 161,500 km(2 of forest, coincident with an area of recent or ongoing tectonic uplift, rapid mechanical erosion and poorly drained soils rich in exchangeable cations. Each bamboo population is confined to a single spatially continuous patch or to a core patch with small outliers. Using spatial congruence between pairs of mature-stage maps from different years, we estimate an average life cycle of 27-28 y. It is now possible to predict exactly where and approximately when new bamboo mortality events will occur. We also map 74 bamboo populations that flowered between 2001 and 2008 over the entire domain of bamboo-dominated forest. Population size averaged 330 km(2. Flowering events of these populations are temporally and/or spatially separated, restricting or preventing gene exchange. Nonetheless, adjacent populations flower closer in time than expected by chance, forming flowering waves. This may be a consequence of allochronic divergence from fewer ancestral populations and suggests a long history of widespread bamboo in the southwest Amazon.

Bamboo-dominated forests of the southwest Amazon: detection, spatial extent, life cycle length and flowering waves.

Science.gov (United States)

de Carvalho, Anelena L; Nelson, Bruce W; Bianchini, Milton C; Plagnol, Daniela; Kuplich, Tatiana M; Daly, Douglas C

2013-01-01

We map the extent, infer the life-cycle length and describe spatial and temporal patterns of flowering of sarmentose bamboos (Guadua spp) in upland forests of the southwest Amazon. We first examine the spectra and the spectral separation of forests with different bamboo life stages. False-color composites from orbital sensors going back to 1975 are capable of distinguishing life stages. These woody bamboos flower produce massive quantities of seeds and then die. Life stage is synchronized, forming a single cohort within each population. Bamboo dominates at least 161,500 km(2) of forest, coincident with an area of recent or ongoing tectonic uplift, rapid mechanical erosion and poorly drained soils rich in exchangeable cations. Each bamboo population is confined to a single spatially continuous patch or to a core patch with small outliers. Using spatial congruence between pairs of mature-stage maps from different years, we estimate an average life cycle of 27-28 y. It is now possible to predict exactly where and approximately when new bamboo mortality events will occur. We also map 74 bamboo populations that flowered between 2001 and 2008 over the entire domain of bamboo-dominated forest. Population size averaged 330 km(2). Flowering events of these populations are temporally and/or spatially separated, restricting or preventing gene exchange. Nonetheless, adjacent populations flower closer in time than expected by chance, forming flowering waves. This may be a consequence of allochronic divergence from fewer ancestral populations and suggests a long history of widespread bamboo in the southwest Amazon.

Chemistry of coast live oak response to Phytophthora ramorum infection

Science.gov (United States)

Frances S. Ockels; Alieta Eyles; Brice A. McPherson; David L. Wood; Pierluigi Bonello

2008-01-01

Since the mid 1990s, Phytophthora ramorum has been responsible for the widespread mortality of tanoaks, as well as several oak species throughout California and Oregon forests. However, not all trees die, even in areas with high disease pressure, suggesting that some trees may be resistant to the pathogen. The apparent resistance to P....

The presence of Abronia oaxacae (Squamata: Anguidae in tank bromeliads in temperate forests of Oaxaca, Mexico

Directory of Open Access Journals (Sweden)

GI. Cruz-Ruiz

Full Text Available The presence of lizards in bromeliads has been widely documented. Nevertheless, the possibility of some type of preference or specificity among lizards for particular bromeliad species has not yet been investigated. Therefore, this study aims to document the presence of Abronia oaxacae in six species of tank bromeliads found in pine forests, pine-live oak forests, and live oak groves during both the rainy season and the dry season. Three adult individuals of Abronia oaxacae were collected; one in a Tillandsia violácea (pine-live oak forest, one in a T. calothyrsus (live oak grove, and one in a T. prodigiosa (live oak grove. All three specimens were collected in sampling efforts carried out during the dry season. The results of the present study suggest that A. oaxacae shows no preference for a single, specific bromeliad species, although it does have a certain preference for a few select species. The presence of A. oaxacae in bromeliads during the dry season could be related to the cooler, moister microhabitat that these plants represent.

Traditional silvopastoral management and its effects on forest stand structure in northern Zagros, Iran

DEFF Research Database (Denmark)

Valipour, Ahmad; Plieninger, Tobias; Shakeri, Zahed

2014-01-01

and to investigate the effects of these practices on forest stand structure. To understand how the traditional forest management system works, empirical survey methods, in particular face to face interviews and participation in traditional practices have been employed. In general, local livelihoods depend on three......Oak forests of Iran are managed for soil conservation, water quality and other non-market ecosystem services. Nationalization policies in 1963 implied shifts from private ownership and informal traditional management to public ownership and state forest management. In spite of the nationalization......, informal practices and conventional ownership have been continued which has caused considerable conflicts between local people and the state forest administration. The aim of the study was to systematically gather the components of traditional silvopastoral management in these oak forests...

Convergence and conflict perspectives in Scandinavian studies of the legal profession

DEFF Research Database (Denmark)

Hammerslev, Ole

2010-01-01

This article focuses on classic Scandinavian studies of the legal profession. These classic studies, which followed World War II and the development of the Scandinavian welfare states, focused on national developments in the legal profession and its relevance to the development of the states....... It demonstrates how the two research traditions, despite their different theoretical perspectives, build their research on comparatively the same kind of empirical data and methodology and how they reach some of the same conclusions....

Dress in Scandinavian Iconography of the 5-10th centuries AD

DEFF Research Database (Denmark)

Mannering, Ulla

2004-01-01

In the Scandinavian Late Iron Age costume studies plays an important role. The many new finds of gold sheet images comprise an until now unexploited source that can enlight the often fragmented and degraded textile remains.......In the Scandinavian Late Iron Age costume studies plays an important role. The many new finds of gold sheet images comprise an until now unexploited source that can enlight the often fragmented and degraded textile remains....

Scandinavian Symposium on Reactor Waste

International Nuclear Information System (INIS)

1981-09-01

More than 100 delegates forom the Scandinavian countries were gathered for a symposium on September 14-16 1981 at Kungaelv Sweden to discuss nuclear reactor waste. The organisation for the handling of radioactive waste at different countries was presented and the principles of radioactive safety were discussed. The planning of the deposition and storage of waste was described. The proceedings are reproduced on some twenty papers, a number of them written in English. (G.B.)

A Basal Area Increment-Based Approach of Site Productivity Evaluation for Multi-Aged and Mixed Forests

Directory of Open Access Journals (Sweden)

Liyong Fu

2017-04-01

Full Text Available Accurate estimates of forest site productivity are essential for environmental planning and forest management. In this study, we developed a new productivity index, hereafter termed basal area potential productivity index (BAPP, to estimate site productivity for irregular and complex forests characterized by multi-aged, multi-species, and multi-layer stands. We presented the biological relevance of BAPP with its computational details. We also compared BAPP against basal area realized productivity (BARP in order to verify the practicability and reliability of BAPP. Time-series data of the national forest inventory on 1912 permanent sample plots that were located in two main forest types and consisted of oak-dominated mixed forests and other broadleaf forests in northeast China were used to demonstrate the application of BAPP. The results showed that the value of BAPP for each sample plot was larger than or equal to the corresponding BARP value for each forest type. For appropriately managed stands with relatively better site conditions, the values of both BARP and BAPP were almost identical. The values of the difference between BAPP and BARP could therefore be used to effectively assess forest site productivity. Meanwhile, BAPP also provides much reliable and valuable information that can aid decision-making in forest management.

Future needs for Nursing Talents in Scandinavian countries

DEFF Research Database (Denmark)

Jakobsen, Randi Kjelde; Herholdt-Lomholdt, Sine Maria

2017-01-01

Review question/objective: The aim of this review is to systematically identify, appraise and synthesize available text and opinion papers from policy-makers and trade unions in Scandinavian countries (Denmark, Sweden and Norway) containing information about nursing talent needed in healthcare...... systems for the future. The overall objective is to identify and synthesize the opinions of various stakeholders of what they believe is required in terms of nursing talent in Scandinavia. In this review, ‘‘nursing talent’’ refers to certain skills or competencies that are essential within nursing to meet...... the challenges and demands of future health care. The purpose of this review is to provide knowledge about the opinions of two key stakeholders (policy-makers and trade unions) on nursing talent needed in future Scandinavian healthcare systems....

Imeretian oak and a great capricorn beetle – the problem of relations on the territory of Ajameti Managed Reserve (Republic of Georgia

Directory of Open Access Journals (Sweden)

Matsiakh Iryna

2017-09-01

Full Text Available The old-growth endemic Imeretian oak [Quercus robur subsp. imeretina (Steven ex Woronow Menitsky, 1968] is a protected relict Tertiary period tree still preserved in Ajameti Managed Reserve (Republic of Georgia. For a long time, these forests were experienced to the strong anthropogenic influence. The old-age oak trees and the development of root and stem rot have promoted the settlement of great capricorn beetle [Cerambyx cerdo Linnaeus, 1758 (Coleoptera: Cerambycidae]. Both of species are protected under the EU Habitats Directive and listed in the IUCN Red List of Threatened Species. The investigation of settling degree of C. cerdo was conducted at two areas, Ajameti and Vartsikhe, on the edge and in the middle of oak forests in June and October 2014. On both the areas, the number of trees with fly exit holes of great capricorn beetle was higher on the margin of forests where plantations suffer greater of human impact. The number of fly exit holes of imago is significantly increased due to deterioration of sanitary condition of forests. The measures of management conservation at Ajameti Managed Reserve were proposed.

Changes in Soil Carbon and Moisture over the Six Year after Thinning of a Natural Oak Forest

Science.gov (United States)

Kim, S.; Han, S. H.; Li, G.; Chang, H.; Kim, H. J.; Son, Y.

2017-12-01

The objective of this study was to assess the effects of thinning on soil carbon (C) in a natural oak forest in central Korea. The study forest received three different thinning treatments consisting of un-thinned control (UTC) and two thinning intensities (15% and 30% basal area reductions) in March in 2010. Precipitation near the study forest maintained the normal level from 2010 to 2013 (average 1,400 mm year-1), but abnormally decreased from 2014 to 2016 (average 800 mm year-1). To measure total soil C stock and soil moisture conditions, soils were collected from 0-10, 10-20, and 20-30 cm depths in June, 2010, 2013, and 2016, respectively. Soil microbial biomass C and C-cycling enzymes (β-glucosidase, cellobiohydrolase, β-xylosidase, phenol oxidase, and peroxidase) at 0-10 cm depth were determined in June, 2016. Total soil C stock at 0-30 cm depth increased throughout the study period, whereas soil moisture decreased at all depths from 2013 to 2016. Both thinning treatments had higher total soil C stock at 0-30 cm depth and moisture at 10-20 and 20-30 cm depths than the UTC in 2013 and 2016, whereas the treatments showed no effects in 2010. Microbial biomass C at 0-10 cm depth in 2016 also increased because of the thinning treatments, which was positively correlated to total soil C stock. However, any effects of thinning on C-cycling enzymes were not significant. Our results indicate that thinning could contribute to relieving the impacts of decreasing precipitation by enhancing the storage of soil moisture. Furthermore, the change in total soil C stock under thinning might result from the stimulation of microbial potential for retaining organic C as a form of biomass. This study was supported by the Ministry of Environment (2014001810002) and the National Institute of Forest Science of Korea (FM0101-2009-01).

A top-down approach of surface carbonyl sulfide exchange by a Mediterranean oak forest ecosystem in southern France

Science.gov (United States)

Belviso, Sauveur; Reiter, Ilja Marco; Loubet, Benjamin; Gros, Valérie; Lathière, Juliette; Montagne, David; Delmotte, Marc; Ramonet, Michel; Kalogridis, Cerise; Lebegue, Benjamin; Bonnaire, Nicolas; Kazan, Victor; Gauquelin, Thierry; Fernandez, Catherine; Genty, Bernard

2016-12-01

The role that soil, foliage, and atmospheric dynamics have on surface carbonyl sulfide (OCS) exchange in a Mediterranean forest ecosystem in southern France (the Oak Observatory at the Observatoire de Haute Provence, O3HP) was investigated in June of 2012 and 2013 with essentially a top-down approach. Atmospheric data suggest that the site is appropriate for estimating gross primary production (GPP) directly from eddy covariance measurements of OCS fluxes, but it is less adequate for scaling net ecosystem exchange (NEE) to GPP from observations of vertical gradients of OCS relative to CO2 during the daytime. Firstly, OCS and carbon dioxide (CO2) diurnal variations and vertical gradients show no net exchange of OCS at night when the carbon fluxes are dominated by ecosystem respiration. This contrasts with other oak woodland ecosystems of a Mediterranean climate, where nocturnal uptake of OCS by soil and/or vegetation has been observed. Since temperature, water, and organic carbon content of soil at the O3HP should favor the uptake of OCS, the lack of nocturnal net uptake would indicate that its gross consumption in soil is compensated for by emission processes that remain to be characterized. Secondly, the uptake of OCS during the photosynthetic period was characterized in two different ways. We measured ozone (O3) deposition velocities and estimated the partitioning of O3 deposition between stomatal and non-stomatal pathways before the start of a joint survey of OCS and O3 surface concentrations. We observed an increasing trend in the relative importance of the stomatal pathway during the morning hours and synchronous steep drops of mixing ratios of OCS (amplitude in the range of 60-100 ppt) and O3 (amplitude in the range of 15-30 ppb) after sunrise and before the break up of the nocturnal boundary layer. The uptake of OCS by plants was also characterized from vertical profiles. However, the time window for calculation of the ecosystem relative uptake (ERU) of OCS

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

OpenAIRE

Ranius, T.

2002-01-01

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

Cavity-nesting bird abundance in thinned versus unthinned Massachusetts oak stands

Science.gov (United States)

Christopher J.E. Welsh; William M. Healy; Richard M. DeGraaf

1992-01-01

Cavity-nesting birds provide significant benefits to forest communities, but timber management techniques may negatively affect cavity-nesting species by reducing the availability of suitable nest and foraging sites. We surveyed cavity-nesting birds from transects in eight Massachusetts oak stands to examine the effect of thinning with retention of snag and wildlife...

Analysis of landscape patterns and their relationship with oak (Quercus Humboldtii Bonpl.) regeneration in the municipality of Popayan, Cauca

International Nuclear Information System (INIS)

Cabezas Gaviria Alexander; Ospina Montealegre Roman

2010-01-01

Landscape patterns were determined for three different areas having oak populations in the Popayan municipality (Clarete, Rejoya and Pisoje). Two Landsat images from different years and polygons with areas equal or greater than 1.5 hectares were used for land use classification. Patch Analysis software was used in order to determine quantitative variables. Structure description included: number of patches, mean patch size, mean patch index, mean patch fractal dimension and mean perimeter-area ratio. Dispersion and fragmentation were evaluated with the three indexes: Mean Nearest Neighbor Distance, Mean Proximity Index and Interspersion Juxtaposition Index. Community variables included: basal area, terrain slope, light percentage and regeneration density, and were measured in an area of 3600 m2 for each landscape. Landscape and community information were analyzed using principal component analysis (PCA). The first two components explained 91.4% of data variability; they were determined mostly by landscape variables than community factors. Correlation analysis and the Kruskal-Wallis test showed that the variable of major importance regarding oak tree regeneration were the Neighbor Distance in secondary forest patches, the Mean Proximity Index in oak tree forest patches and the Juxtaposition Index in patches of planted forests.

Challenging Scandinavian employment relations

DEFF Research Database (Denmark)

Ibsen, Christian Lyhne; Larsen, Trine Pernille; Madsen, Jørgen Steen

2011-01-01

and employment relations in the Danish, Norwegian and Swedish public sector. In this paper, we argue that although differences exist across the Scandinavian countries, it is evident that they have managed to adopt and implement NPM-inspired reforms without dismantling their universal welfare services and strong......Building on the convergence/divergence approach, this paper examines whether recent new public management (NPM) inspired reforms entailing inter alia cutbacks in the public sector, marketisation and management by performance measures have had significant implications for service provision...... traditions of collective bargaining in the public sector. However, this restructuring is taking its toll on the work environment....

Whole grain foods and health - A Scandinavian perspective

DEFF Research Database (Denmark)

Frølich, Wenche; Aman, Per; Tetens, Inge

2013-01-01

and health effects of the final whole grain products. Future research should consider the specific properties of each cereal and its processing methods to further identify the uniqueness and health potentials of whole grain products. This would enable the authorities to provide more specific food......The food-based dietary guidelines in the Scandinavian countries that recommend an intake of minimum 75 g whole grain per 10 MJ (2,388 kcal) per day are mainly derived from prospective cohort studies where quantitative but little qualitative details are available on whole grain products....... The objective of the current paper is to clarify possible differences in nutritional and health effects of the types of whole grain grown and consumed in the Scandinavian countries. A further objective is to substantiate how processing may influence the nutritional value and potential health effects...

Reallocation and nutrient use efficiency in Antioquia central forests

International Nuclear Information System (INIS)

Leon Pelaez, Juan; Gonzalez Hernandez, Maria; Gallardo Lancho, Juan

2009-01-01

We have studied nutrient related variables such as reallocation, nutrient use efficiency (NUE) and fine litter fall for three years in an oak forest Quercus humboldtii Bonpl. and also in some other forest plantations like pine, Pinus patula, and cypress, Cupressus lusitanica, in Antioquia, Colombia. Leaf litter quantities returned to the soil followed a falling sequence: oak (5313.3 kg ha-1 year-1) > pine (4866.5 kg ha-1 year-1) > cypress (2460.3 kg ha-1 year-1). The coniferous species showed the highest NUE for the majority of elements that were examined, except for P, which reached its absolute maximum in the oak forest -where a clear reallocation of this nutrient was also recorded-, probably because of its reduced availability in these volcanic ash-derived soils. Nutrient reallocation allows the conservation of the nutrients by reducing its loss from leaching and litter-fall, thereby closing the nutrient cycle in this native forest. In fact, P gains from net deposition were found there -this includes foliar leaching and atmospheric deposition-, which indicates that the species absorbs the P contained in rainfall from the leaves before it reaches the forest ground. N slow-efficiency use was probably due to its low availability in soil, given its low mineralization rates in these montane forests. K showed the highest reallocation values. Such figures are influenced by its clearly mobile character, according to the highest net deposition levels also verified for this element. With the exception of Mg, there was no clear relationship between the reallocation process and NUE.

Effects of thinning intensity and crown class on cherrybark oak epicormic branching five years after treatment

Science.gov (United States)

Luben D. Dimov; Erika Stelzer; Kristi Wharton; James S. Meadows; Jim L. Chambers; Kenny Ribbeck; E. Barry Moser

2006-01-01

Thinning in oak-dominated stands may have many desirable consequences, including increases in tree growth and mast production. One of the potential disadvantages, however, is the proliferation of epicormic branches, which leads to reduction in lumber quality and value. We assessed the effects of thinning intensity and initial crown class on cherrybark oak (...

Seasonal dynamics, age structure and reproduction of four Carabus species (Coleoptera: Carabidae) living in forested landscapes in Hungary

DEFF Research Database (Denmark)

Kádár, Ferenc; Fazekas, Judit P.; Sárospataki, Miklós

2015-01-01

Seasonal dynamics and reproductive phenological parameters of four Carabus species (C. convexus, C. coriaceus, C. germarii and C. hortensis) common in Hungary were studied by pitfall trapping and dissection. Beetles were collected in an abandoned apple orchard and in the bordering oak forest near...... Budapest (Central Hungary), in 1988–1991. The sex ratio was male-dominated, but this was significant only for C. coriaceus. The catch of C. germarii adults showed relatively short activity period with unimodal curve, but activity was longer and bimodal for the other three species. Adults of C. germarii...

Experiences of Scandinavian nurses in discussing sexuality with patients, clients and residents

DEFF Research Database (Denmark)

Laursen, Birgitte Schantz; Rasmussen, Philippa; Conroy, Tiffany

2017-01-01

REVIEW QUESTION/OBJECTIVE:: The objective of this review is to critically appraise, synthesize, and present the best available evidence to address the question: How do Scandinavian nurses experience discussing sexual issues with patients, residents and clients?......REVIEW QUESTION/OBJECTIVE:: The objective of this review is to critically appraise, synthesize, and present the best available evidence to address the question: How do Scandinavian nurses experience discussing sexual issues with patients, residents and clients?...

A Scandinavian Experience of Register Collaboration: The Nordic Arthroplasty Register Association (NARA)

DEFF Research Database (Denmark)

Havelin, Leif I; Robertsson, Otto; Fenstad, Anne M

2011-01-01

The Nordic (Scandinavian) countries have had working arthroplasty registers for several years. However, the small numbers of inhabitants and the conformity within each country with respect to preferred prosthesis brands and techniques have limited register research.......The Nordic (Scandinavian) countries have had working arthroplasty registers for several years. However, the small numbers of inhabitants and the conformity within each country with respect to preferred prosthesis brands and techniques have limited register research....

Spatial modeling and inventories for prioritizing investment into oak-hickory restoration

Science.gov (United States)

Louis R. Iverson; Matthew P. Peters; Jarel L. Bartig; Joanne Rebbeck; Todd F. Hutchinson; Stephen N. Matthews; Susan Stout

2018-01-01

Oak (Quercus spp.) and hickory (Carya spp.) forests in the eastern United States provide a host of ecosystem services as their mast are prized by wildlife, the timber is a valued commodity, and they are generally more tolerant of extreme weather events under a changing climate. They are, however, undergoing a severe decline in...

Biogeochemistry and plant physiological traits interact to reinforce patterns of post-fire dominance in boreal forests

Science.gov (United States)

Shenoy, A.; Kielland, K.; Johnstone, J. F.

2011-12-01

-specific differences in N preference coupled with their respective physiological response to fire severity represent a positive feedback loop that reinforce the opposing stand dominance patterns that have developed at the two ends of the fire severity spectrum. Shifts in forest composition from the current dominance by conifers to a future landscape dominated by deciduous forest are of concern due to impacts on climate-albedo feedbacks, forest productivity, ecosystem carbon storage, and wildlife habitat use.

Soil heat flux measurements in an open forest

NARCIS (Netherlands)

vanderMeulen, MJW; Klaassen, W; Kiely, G

1996-01-01

The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

Soil Heat Flux Measurements in an Open Forest

NARCIS (Netherlands)

Meulen, M.W.J. van der; Klaassen, W.

1996-01-01

The soil surface heat flux in an open oak forest was determined at four locations to account for the heterogeneity of the forest. Soil temperatures and soil water content were measured at several depths and an integration method with three layers was used. The thickness of the bottom layer was

Tree seed rain and seed removal, but not the seed bank, impede forest recovery in bracken (Pteridium aquilinum (L.) Kuhn)-dominated clearings in the African highlands.

Science.gov (United States)

Ssali, Fredrick; Moe, Stein R; Sheil, Douglas

2018-04-01

Considerable areas dominated by bracken Pteridium aquilinum (L.) Kuhn occur worldwide and are associated with arrested forest recovery. How forest recovery is impeded in these areas remains poorly understood, especially in the African highlands. The component processes that can lead to recruitment limitation-including low seed arrival, availability and persistence-are important determinants of plant communities and offer a potential explanation for bracken persistence. We investigated key processes that can contribute to recruitment limitation in bracken-dominated clearings in the Bwindi Impenetrable National Park, Uganda. We examined if differences in seed rain (dispersal limitation), soil seed bank, or seed removal (seed viability and persistence) can, individually or in combination, explain the differences in tree regeneration found between bracken-dominated areas and the neighboring forest. These processes were assessed along ten 50-m transects crossing the forest-bracken boundary. When compared to the neighboring forest, bracken clearings had fewer seedlings (bracken 11,557 ± 5482 vs. forest 34,515 ± 6066 seedlings/ha), lower seed rain (949 ± 582 vs. 1605 ± 335 tree seeds m -2  year -1 ), comparable but sparse soil seed bank (304 ± 236 vs. 264 ± 99 viable tree seeds/m 2 ), higher seed removal (70.1% ± 2.4% vs. 40.6% ± 2.4% over a 3-day interval), and markedly higher rodent densities (25.7 ± 5.4 vs. 5.0 ± 1.6 rodents per 100 trapping sessions). Camera traps revealed that rodents were the dominant animals visiting the seeds in our seed removal study. Synthesis : Recruitment limitation contributes to both the slow recovery of forest in bracken-dominated areas, and to the composition of the tree species that occur. Low seed arrival and low persistence of unburied seeds can both explain the reduced density of seedlings found in bracken versus neighboring forest. Seed removal, likely due to rodents, in particular appears sufficient to

Spatial pattern of tree diversity and evenness across forest types in Majella National Park, Italy

Directory of Open Access Journals (Sweden)

Mohammad Redowan

2015-09-01

Full Text Available Background Estimation of tree diversity at broader scale is important for conservation planning. Tree diversity should be measured and understood in terms of diversity and evenness, two integral components to describe the structure of a biological community. Variation of the tree diversity and evenness with elevation, topographic relief, aspect, terrain shape, slope, soil nutrient, solar radiation etc. are well documented. Methods Present study explores the variation of tree diversity (measured as Shannon diversity and evenness indices of Majella National Park, Italy with five available forest types namely evergreen oak woods, deciduous oak woods, black/aleppo pine stands, hop-hornbeam forest and beech forest, using satellite, environmental and field data. Results Hop-hornbeam forest was found to be most diverse and even while evergreen Oak woods was the lowest diverse and even. Diversity and evenness of forest types were concurrent to each other i.e. forest type which was more diverse was also more even. As a broad pattern, majority portion of the study area belonged to medium diversity and high evenness class. Conclusions Satellite images and other GIS data proved useful tools in monitoring variation of tree diversity and evenness across various forest types. Present study findings may have implications in prioritizing conservation zones of high tree diversity at Majella.

Influence of oak planting on microelement composition (on example of Mn) of ordinary chernozem