species (Figure 1 and Table 1). In two stands, sweet chestnut appears naturally, building autochthonous communities, while this species was artificially intro- duced in four stands (Table 1). Planted sweet chestnut trees in the natural sessile oak forests near the Vršac Mountains, part of the Carpathian basin in Serbia were sampled and analysed together with sessile oak trees in the same locality (Table 1). Another planted forest established on the natural stand of Q. frainetto was sampled in the area near Kruševac in central Serbia (Table 1). Two natural and two planted stands of sweet chestnut trees were sampled in southern Serbia in different localities near Vranje, including Kozji Dol, Milivojce, Muhovac and Sobina, respectively (Table 1), where this species composes one of the rarely found autochthonous communities in Serbia. Q. petraea or Q. frainetto naturally appear in the mixtures in the latter four stands, and they were also inspected for the presence of the symptoms of the disease.
11 Read more
Criteria thresholds for the canopy are set to ensure sufficient canopy cover as well as a good presence of target species. Canopy height is also examined, with alluvial woodlands having a lower threshold than sessile oak woods. Canopy structural characteristics were generally in good condition in the woodlands surveyed. Canopy cover was especially good in sessile oak woods, with all plots passing this criterion. A small number of plots failed this criterion in alluvial woodlands, site 242 Grantstown Wood in particular having severe canopy die-back problems due to persistent flooding caused by a blocked culvert which had a serious negative effect on Fraxinus excelsior trees in the wood. A small percentage of plots failed the criterion that examines the percentage of canopy composed of target species, such as 1317 the Gearagh (a 91E0 site), 1785 Treanlaur and 1491 Ummera Wood (both 91A0 sites). In the last two sites, the problem was due to competition from non-native species such as Acer pseudoplatanus and Fagus sylvatica. The issue in the Gearagh, however, was due to a higher proportion of non-target native species such as Betula pubescens. This could be caused by a slight difference in soil or drainage conditions in part of the polygon (e.g. drier), or could be due to part of the site being at a different successional stage from the rest of the woodland. This is of less concern, particularly as there is no shortage of target species throughout the woodland as a whole.
73 Read more
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.
ABSTRACT: This paper deals with the measurement and evaluation of pedunculate and sessile oaks on five provenance trial plots located in the forest regions Západočeská pahorkatina, Jihočeská pánev, Hornomoravský úval, Dolnomoravský úval, Bílé Karpaty and Vizovické vrchy at the age of 20 years. Height and diameter growth were measured and ana- lysed and the quality of tree stems was recorded. Sampled seeds originated from certified stands for seed production located in the Hercynian and Carpathian regions of the Czech Republic. Differences between the two species result from their ecological requirements. A comparison of the two species indicates that pedunculate oak at young age grows better than sessile oak in its typical site conditions. Sessile oak grows relatively worse on the plots situated in floodplain site conditions because it does not tolerate the high levels of groundwater. But the differences were not statistically significant. Significant differences in growth parameters were confirmed within each species among plots and provenances. Large differences in stem shape quality were also recorded already in the early growth phase. In some provenances straight stems were present in up to 56% of the individuals, however, in others straight stems did not appear at all. The total results showed that some pedunculate and sessile oak provenances are more adaptable to site conditions and they suffer lower losses while achieving very good growth.
17 Read more
Abstract: Different variants of regeneration felling or different light conditions (total site factor 15–95%) and weed control were evaluated in relation to the 4-year development of individuals of regenerated sessile oak. The regenera- tion density is not dependent on light conditions. The highest mortality occurs on the open area of clear felling. For a certain time in youth, it is possible to consider oak as a shade-tolerating species. With the increasing light intensity the diameter and height growth of oak seedlings increases proportionally, being the highest at 100% light intensity. However, to support at least medium-fast growth, the species requires minimally 50% light intensity (smaller closed clear-felled areas). On the other hand, more extensive unprotected cleared areas appear to be quite unsuitable at the initial stages of regeneration. The positive effect of weed control on the success and growth of natural regeneration is questionable. We recommend developing the regenerated stand by means of a series of small-area (about ≤ 0.3 ha) two-stage felling with a medium-long regeneration period (15–20 years).
10 Read more
Three variants of growing sessile oak (maturing high forest) on typical fertile sites of lower elevations in the Czech Republic were compared from the production and quality point of view. The variants were as follows: mixed forest unmanaged more than 30 years, mixed forest and pure stand subjected to standard management measures based on positive selection. Surprisingly, no essential diﬀ erences were found either in the production potential or in the quality of sessile oak at comparing the managed mixed forest and the monoculture. A higher number of crop oak trees in the monoculture was compensated in the mixed forest by the representation of other tree species. The unmanaged mixed forest exhibited worse quality of oak crowns, which closely correlates with the volume yield. Therefore, it is recommended to apply tending measures on the principle of thinning from above with the comprehensive management of crowns in selected targeted trees even at their higher age. sessile oak, mixed forest, monoculture, production, quality, tending
10 Read more
Shading effects of the mother trees depend on the size of the gap. Larger gaps are more illuminated but relations between gap size and soil moisture content are less evident (6, 12, 13). Interception of the canopy and root concurrence of the parent stand decrease with gap area while soil temperature increases (12). Although pedunculate and sessile oak (Quercus robur L. and Q. petraea (Mattuschka) Liebl.) are major tree species in many forest types throughout Europe, very little is known about their gap-phase regeneration (e.g. 14, 15, 16, 17, 18). High weed abundance and competition of fast growing associated tree species can make pedunculate oak regeneration in gaps rather difficult, similarly to the more traditional regeneration methods (18). Bobiec (16) found that in natural gaps of various sizes of a mixed deciduous forest (Tilio-Carpinetum) lime (Tilia cordata Miller) and hornbeam (Carpinus betulus L.) could regenerate well but pedunculate oak could regenerate hardly. In mesic sites, gap formation or gap cutting promotes spread of blackberry (Rubus fruticosus agg.) (19, 20). Blackberry is known as one of the strongest competitors of sessile or pedunculate oak (19, 21, 22), though some results showed that pedunculate oak could grow over the blackberry layer (23). By contrast, Tobisch (19) noticed the opposite in a Central-European sessile oak-hornbeam forest. So far, it has been not clarified how gap size influences the height growth of sessile oak and hornbeam seedlings, as well as, blackberry proliferation. It has been not studied, either, how differently seedlings of sessile oak and hornbeam grow and how cover of blackberry changes in various topographical positions within gaps of a given size. This paper addresses these questions by studying circular gaps of 15, 30 and 45 m in diameter (i.e., approximately 0.5, 1 and 1.5 tree length) in a sessile oak-hornbeam stand. Furthermore, spatial differences of seedling height were related to blackberry cover and soil moisture content as indicated by the herb layer.
13 Read more
pine in the Alps, namely in the French part by Rol- land et al. (1998), in the Italian part of the Alps by Anfodillo et al. (1998) and in the Austrian part by Oberhuber and Kofler (2000, 2003). In Germany Knott (2004) studied seasonal dynam- ics of diameter increment of fir and beech, Gru- ber (2002) only of beech and Röhle et al. (2010) of spruce, pine and beech. Vejpustková et al. (2004) and Novák et al. (2010) studied the effect of cli- matic factors on spruce and pine diameter incre- ment in the Czech Republic. In Slovakia Ďurský and Pavlíčková (1998) dealt with the issue of climate and radial increment of pine, Šmelko and Miková (1999), Pajtík and Ištoňa (2003) inves- tigated Turkey oak and Petráš et al. (2006, 2007) dealt with sessile oak. Recently, Kahle et al. (2008) studied the effect of precipitation on radial incre- ments of spruce, beech and pine trees in several places in Scandinavia, Western and Central Europe. According to their results it is not probable that the higher increment of forests in Europe is a conse- quence of higher precipitation. In the same study Mellert et al. (2008) did not clearly confirm the
10 Read more
The category of larger trees and their response to growth change has been used for estimates of stand growth and production in competition models for a long time (Wykoﬀ , 1990; Monserud and Sterba, 1996; Yang et al., 2009; Ledermann, 2010; Pretzsch and Biber, 2010). A hypothesis about the inability of large (old) trees to increase their growth as a result of stand density reduction as tested in this paper has been used also by Latham and Tappeiner (2002) and York et al. (2010). These papers focused primarily on conifers. However, from the perspective of hypothesis deﬁ nition, they are very similar methods and are therefore applicable. A decrease in increment is generally expected when a tree reaches a certain age limit (Weiner and Thomas, 2001). The increment may be enhanced by suitable stand care, such as tree release. Our results reveal that adult sessile oaks of sprout origin are already capable of a fast response to release through increased increment during the second year a er release. The fast response may be explained using a theory by Jones and Thomas (2004), in which tree release is followed by a brief drop in growth due to shock (a shock caused by the increased supply of available light and drought), followed by an increase; upon culmination, the growth returns to the original value that it had prior to the creation of the gap. A similar response speed to release is given by Johnson et al. (2009) for young white oak stands (Quercus alba L.) and by York et al. (2010) for old giant sequoia trees (Sequoiadendron giganteum IV: Estimated parameter values of individual models for the basal area increment in sessile oak three years a er thinning
11 Read more
Materials and Methods: Our study integrates climate change scenarios for the region of Serbia together with the current distribution of forest tree species. Evaluation was performed using forest aridity index which takes into account mean temperatures and sums of precipitation of the critical months during the growing season. Distribution data of the nine most abundant tree species in Serbia (European beech, Turkey oak, Sessile oak, Hungarian oak, Pedunculate oak, Norway spruce, Silver fir, Black and Scots pine) were taken from the National Forest Inventory.
Old sessile oak woods with Ilex and Blechnum in the British Isles habitat occurs in Pollnaknockaun Wood where significant fragments of mature woodland remain among conifer plantations, which have been mostly cleared. Until large-scale commercial forestry operations began in the 1930s and 1940s, Pollnaknockaun Wood was part of one of the most extensive oak woodlands in Ireland, along with the woodlands of Derrycrag (SAC 000261) and Rosturra (SAC 001313). Much of western portion of the SAC is designated as a Nature Reserve. As part of the National Survey of Native Woodlands (NSNW), the sub-site Pollnaknockaun Wood (NSNW site code 1610) was surveyed by Perrin et al. (2008). The minimum area of old oak woodland in the SAC is estimated to be 27.5ha. Map 3 shows the surveyed woodland classified as 91A0 (27.5ha) in the SAC. NB further unsurveyed areas may be present in the SAC
11 Read more
Old sessile oak woods with Ilex and Blechnum in the British Isles in Danes Hole, Poulnalecka SAC was surveyed and mapped as part of the National Survey of Native Woodlands (NSNW) (Perrin et al., 2008) in the sub-site Ballykelly Woods (NSNW site code 1580). Perrin et al. (2008) mapped a minimum area of 5.72ha of old oak woodland within the SAC boundary. Ballykelly Woods (1580) was also included in a national monitoring survey (O'Neill and Barron, 2013). Map 2 shows the surveyed woodland classified as 91A0 (5.72ha) by Perrin et al. (2008). It is important to note that further unsurveyed areas are present within the SAC
14 Read more
Mycorrhizal roots of the deciduous trees European beech ( Fagus sylvatica (L.)) and Sessile oak ( Quercus petraea (MattuschkaLiebl.)) and the conifers Norway spruce ( Picea abies (L.) H. Karst.) and European larch ( Larix decidua (Mill.)) associated with the ectomycorrhizal fungi matt bolete ( Xerocomus pruinatus (Fries 1835)) or bay bolete ( X. badius (Fries 1818)) were analysed with respect to the occurrence of dihydrolipoyl dehydrogenase (EC 184.108.40.206) allozymes. In root tissues of the two deciduous trees, two gene loci could be visualized after cellulose acetate electrophoresis while three loci were ex- pressed in root tissues of the two coniferous species. The two fungal species and further ectomycorrhizal fungi expressed exclusively one dihydrolipoyl dehydrogenase gene. In Xerocomus pruinatus and X. badius , the dihydroli- poyl dehydrogenase gene consists of 1460 bp and 1370 bp, respectively, in- cluding five introns each consisting of 52 bp. Their DNA sequences corres- pond to 70 to 90% to other fungal dihydrolipoyl dehydrogenase genes. One monomer of the dimeric dihydrolipoyl dehydrogenase enzyme consists of 486 ( X. pruinatus ) or 454 ( X. badius ) amino acids which sum up to a molecular mass of 55 kDa ( X. pruinatus ), respectively 52 kDa ( X. badius ). The number of positively charged amino acid residues makes 79 ( X. pruinatus ) and 68 ( X. badius ) and the number of negatively charged amino acid residues was calcu- lated to make 46 ( X. pruinatus ) and 48 ( X. badius ); isoelectric points make 9.99 ( X. pruinatus ) and 9.68 ( X. badius ). Calculated three dimensional struc- tures reveal a short NADH binding site being part of a larger FAD-binding site and a binding/dimerization domain.
22 Read more
DOI: 10.4236/ajcc.2018.72020 338 American Journal of Climate Change with young forest stand stages, the literature generally only focuses on seedlings    and no study exists concerning the analysis of radial growth on young trees ( i.e. under 10 - 15 years old). The goal of this article is therefore to investigate the adaptability of different oak species to drought, comparing two native and one non-native species. First, stand measurements was performed within the framework of the “Mooswald” afforestation experiment. Then, re- trospective analyses of radial growth were realized to compare the three oak spe- cies in terms of resistance ( i.e. , the ratio between the radial growth performance during and prior to the drought year), recovery ( i.e. , the ratio between the per- formance after (PostDr) and during the disturbance) and resilience ( i.e. , the ratio between the radial growth performance after and prior to the drought year). Compared to the native oak species (pedunculate oak and sessile oak), we deter- mined: 1) whether or not the non-native Turkey oak shows higher stand volume within the first eight years after planting and less mortality in response to the se- vere drought of summer 2015; and 2) if Turkey oak is more resistant and more resilient to radial growth depressions in response to drought years (such as 2013 and 2015). This young afforestation provides information about the relative per- formance of the three oak species in the crucial establishment phase of forests.
19 Read more
This study is one of the rare chemical analysis works which was don e on h eartwood, sapwood an d bark of Strendzh a oak (Q.hartwissiana), Sessile oak (Q. petraea) and Eastern Black Sea oak (Q.pontica), grown in Eastern Black Sea region. This present study shows that these oak species grown in Eastern Black Sea region have rich extractive content. Particularly, their barks have percentage of 8.66-18.85 % extractive component. Also, in heartwoods and sapwoods, there are percentages of 6.20-10.80 % and 3.17-5.35 % extractive component, respectively. On the other hand, in heartwoods, sapwoods and barks of Strendzha oak, 40,30 and 48 compounds were identified, respectively by GC-MS . It is important to note that resolution values of barks of oak species grown in Eastern Black Sea region are higher than resolution values of heartwoods and sapwoods. When oak species were compared to angiosperm tree species, chemical compounds and resolution values of woods of Strendzha oak, Sessile oak and Eastern Black Sea oak were found quite high.
The research plots were created in pure red oak stands whose ages covered the time period as long as possible from 17 to 159 years. The plots are on the same or similar site types (acid and/or poor) containing at least 100 trees and avoiding edges of the stand. Similar series in sessile oak stands were established to create pairs of the same (or similar) age for both species. The total number of plots was 13, 7 plots of red oak and 6 plots of sessile oak. Basic information on research plots is given in Table 1.
Community types identified for this area were: Acidic Cove Forest (Typic Subtype) (AC), Canada Hemlock Forest (Typic Subtype) (CH), Chestnut Oak Forest (Dry Heath Subtype) (CODH), Chestnut Oak Forest (Herb Subtype) (COH), Chestnut Oak Forest (Rhododendron Subtype) (COR), Chestnut Oak Forest (White Pine Subtype) (COWP), Montane Cliff (Acidic Subtype) (MCA), Montane Cliff (Mafic Subtype) (MCM), Montane Oak-Hickory Forest (Acidic Subtype) (MOH), Montane Oak-Hickory Forest (White Pine Subtype) (MOHW), Pine Oak Heath (Typic Subtype) (POH), Rich Cove Forest (Montane Intermediate Subtype) (RC), Rocky Bar (Twisted Sedge Subtype) (RB), Spray Cliff (SC), Swamp Forest Bog Complex (Typic Subtype) (SFB), and White Pine Forest (WP). Table 2-1 shows the sample size for each community type and method of sample point identification. (For a complete list of sample points and their community types see Appendix A. A species list for the study area is provided in Appendix B.)
76 Read more
EMR of large colonic polyps is also roughly three times less expensive than surgical management, and this effect is amplified among older patients with multiple comorbidities (Keswani RN, Law R, Ciolino JD, et al 2016). One of the biggest challenge in the removal of large, flat and sessile polyps comes from a lack of awareness and access to high- quality EMR services. Sessile serrated polyps were notably more difficult to remove in their entirety compared with adenomas; large, sessile serrated polyps are most likely to progress to cancer. The best way to avoid the incomplete removal of a lesion is to perform EMR (Bhurwal A, Bartel MJ Heckman MG, et al 2016). The aim of the work is to view the role of endoscopy in resection of sessile clonic polyps and review different techniques of endoscopic resection identifing their safety and efficacy. Time consuming, rate of complete and incomplete resection, complications as bleeding or perforation intra operative or delayed post operatively, rate of recurrancy and rate of convertion to surgery.
The community of the highest level, combining all considered communities, is the regional PPF community, which can be considered as a regional- formational one (see Figure: IV; A, B). This is FR- community, since it is F. robusta, who claims the role of species-founder of PPF communities: it is widespread, it has a stable and high representation in the PPF community at all hierarchical levels, with a higher representation in the stands, less affected by anthropogenic activities. And, importantly, this species, according to our observations, is the first among the species of community for digesting of new environment – it locates on middle-aged and older trees of oak with seed origin, in oak plantations of artificial origin (for example, in forest belts).
Assessment. The letter flatly disallowed such an option and intimated court action if schools were found to be avoiding delivery of the SBAC assessments. This was in response to the concerns and actions of other schools last year during the field test. Live Oak will continue to move forward in full compliance with state requirements for SBAC testing. Sebastopol Charter and Novato Charter are also taking a conventional approach and are actively engaged in developing an appropriate model for the use of such equipment for the lower grades (3-5). Live Oak has expanded its site license for the online keyboarding software we’ve used the past couple years. Our plan is to have grades 5-8 conduct basic keyboarding practice. Eventually this will be come a single year task likely conducted in year 5, though the instruction of
87 Read more