Occurrence and management of oak in southern Swedish forests

This article describes the current proportions of forest types with oak (Quercus robur and Q. petraea) in southern Sweden, provides an overview of oak distribution over time and reviews literature about oak regeneration relevant for the region. Further we discuss silvicultural possibilities to maintain and promote oak in Scandinavia. In Götaland pure oak forest covers 1% of the forest area and mixed forest types with > 10% oak proportion cover approximately 10% of the area. Common types of mixture are spruce-oak and pine-oak forest. Both mixtures are frequent in mature forest, especially pine-oak. Additionally, about one third of spruce-oak mixtures can be found in medium-aged forest. Intensive management would be necessary to promote single oak trees in old pine stands or spruce plantations, but the proportion of oak in coniferous forest provides some potential to maintain additional oak trees. The distribution of acorns by Jays, enhanced measures against browsing, and the release of single oak trees from competing tree species could help to maintain more oak trees for nature conservation. However, regarding management of oak for timber production, conventional methods are recommended. Planting after clear cutting of coniferous forest, or short shelter periods after mast years in oak stands, are established methods to regenerate pure oak stands. Another possibility to develop mature oak forest are mixed oak-spruce plantations, as traditionally practised in a small region in southern Sweden. The different approaches of oak management in Sweden were presented in April 2012 on the annual meeting of the section silviculture of DVFFA (German Union of Forest Research Organizations) in Wermsdorf near Leipzig to give an overview and access to recent forest research in Sweden

Ground beetle assemblages in Beijing’s new mountain forests

Mature forests have been almost completely destroyed in China’s northern regions, but this has been followed by large-scale reforestation in the wake of environmental degradation. Although future forest plantations are expected to expand over millions of hectares, knowledge about the ecology and biodiversity of China’s replanted forests remains very limited. Addressing these knowledge gaps, we recorded ground beetle (Coleoptera: Carabidae) communities in five secondary forest types: plantations of Chinese Pine (Pinus tabulaeformis) and Prince Rupprecht’s Larch (Larix principis-rupprechtii), Oak (Quercus wutaishanica) and Asian White Birch (Betula platyphylla) woodlands, and naturally regenerated mixed forest. Species richness peaked in mixed forests, while pine and oak woodlands harboured discrete communities of intermediate species richness. Oak, pine and mixed forest habitats also showed high levels of species turnover between plots. Canopy closure was an important factor influencing ground beetle assemblages and diversity, and a number of forest specialist species only occurred in pine or oak forests. We believe that some forest specialists have survived earlier deforestation and appear to be supported by new plantation forests, but maintenance of secondary native oak and mixed forests is crucial to safeguard the overall species pool

Evaluating The Impacts Of Southern Pine Beetle On Pitch Pine Forest Dynamics In A Newly Invaded Region

Southern pine beetle (SPB; Dendroctonus frontalis Zimmerman), a native insect that has historically affected pine ecosystems in the southeastern U.S., has recently expanded northward causing extensive tree mortality in pitch pine (Pinus rigida) and pitch pine-oak (Quercus spp.) forests across much of eastern Long Island, NY. Given the historic lack of SPB within these fire-dependent ecosystems, little is known regarding its impacts to forest composition, forest structure, or fuel loading. This study examined the short-term effects of SPB-induced tree mortality on the structure, composition, and fuel loading of pitch pine and pitch pine-oak communities to inform management recommendations and projections of future forest conditions and fire hazard. Overstory pine basal area declined following SPB infestation and infestation suppression management, particularly in pitch pine forests. These treatments did not impact the density or composition of seedlings and saplings, with hardwood species, including scarlet oak (Quercus coccinea), scrub oak (Quercus ilicifolia), and black gum (Nyssa sylvatica), making up the majority of species in this layer and pine representing \u3c6% of stems. Likelihood of herbivory was influenced partly by species, with pitch pine less likely to be browsed than white oak and scarlet oak. SPB infestation significantly increased the snag component of both forest types, which largely became downed coarse woody debris (CWD) following suppression management. Treatments did not significantly influence understory species assemblages. Understory communities in pitch pine stands were characterized by Vaccinium angustifolium prior to SPB or suppression management, with these disturbances leading to an increase in the diversity of understory communities. In contrast, infestation decreased variation in understory species assemblages in pine-oak forests and encouraged regeneration of pitch pine and scarlet oak, while suppression increased diversity largely through increases in disturbance-adapted species, such as Smilax rotundifolia. SPB infestation decreased the biomass of live fuels and subsequently increased loading of dead fuels in both forest cover types. Suppression management felled preexisting and SPB-generated snags, especially in pitch pine forests, transforming vertical fuels into horizontal CWD. Collectively, results indicate SPB could functionally eliminate pitch pine without additional management intervention to maintain this species. Suppression efforts to reduce SPB impacts may accelerate succession towards hardwood dominance, particularly in pine-oak stand, leading to dramatic shifts in forest conditions across the Long Island Pine Barrens. SPB and suppression management significantly increase dead fuel loading and felling of snags during suppression served to decrease the density of ladder fuels effectively decreasing the risk of crowning. However, heavy CWD loading may also promote volatile fire behavior. Therefore, forest managers must weigh the expected potential impacts of SPB relative to changes to fuel structure and composition generated by suppression management activities. Our results demonstrate short-term effects of SPB and suppression management. Given the limited experience with SPB in these forests and the results of this study, further research on fire behavior effects and patterns of stand development over the long-term are needed

EFFECTS OF FIRE ON STRUCTURE AND COMPOSITION OF VEGETATION COMMUNITY IN PINE FORESTS, NAM NAO NATIONAL PARK, THAILAND

Anthropogenic forest fires, including those occurring in the pine forests of Thailand, have been widely reported. Although pine forests are fire dependent, too frequent burning could be unhealthy for the forest as it might result in nutrient depletion and ecosystem degradation. Hence, this study aimed to examine the effects of forest fire on the vegetation structure and composition of a degraded pine forest (PF) and in a mixed pine-oak forest (O-PF) of Phu Kum Khao, Nam Nao National Park, Phetchabun Province, Thailand. The effects of fire in one year were studied using three 50 x 50 m experimental plots established in each forest type. Results showed that fire events caused a significantly higher tree mortality rate in the degraded pine forest than in the mixed pine-oak forest. Moreover, the seedling ratio (number of sprout to number of seedling ratio) in the mixed pine-oak forest was higher than in the degraded pine forest.  Although the sapling and seedling diameters were slightly different between the sites, no significant effect of burning was observed on the sapling and seedling density, diameter and height. This might be due to the high variation of fire behavior in each plot. Since forest fires are a potential factor that might cause forest degradation in the study area, further studies on the effects of fire frequency on vegetation structure and composition is needed to provide sufficient fire control measures for efficient forest fire management to prevent further ecosystem degradation

Influence of Gambel oak on breeding birds in ponderosa pine forests of northern Arizona

Gambel oak (Quercus gambelii) is widely distributed in the Southwestern United States, where it frequently occurs in association with ponderosa pine (Pinus ponderosa). Fire suppression and fuelwood harvest likely have reduced oak abundance within the pine-oak type. Gambel oak occurs in multiple age-related growth forms, from small shrubs to large, old trees, and may provide important foraging and nesting habitat for breeding birds. I compared attributes of breeding bird communities in 16 northern Arizona ponderosa pine stands from 1993-1995, that were structurally similar except for the presence or absence of Gambel oak. Overlap in bird species composition was high; pine and pineoak stands had a mean Jaccard similarity value of 0.67. Five species were unique to pine stands, whereas 10 species were largely restricted to or only found in pine-oak stands. Overall bird diversity was significantly higher in pine-oak stands, which also had more species of Neotropical migrants, ground nesters, primary cavity excavators, and secondary cavity users than did pine stands. Pine and pine-oak stands had similar species evenness and similar rates of annual species turnover. Total bird abundance did not differ between cover types; however, primary cavity excavators were more abundant in pine-oak stands. Because of the apparent positive influence of oak on breeding birds, forest managers are encouraged to use treatments that retain and enhance the various growth forms of Gambel oak found in pine-oak stands

Height. Growth of Loblolly and Slash Pine Plantations in the Northern Post-Oak Belt of Texas

Age accounted for over 70% of the variation in tree height of 1O- to 44- year-old loblolly pine (Pinus taeda L.) and slash (Pinus elliottii Engelm.) plantations established on deep sands, moderate sands, and nonsandy soils in the Northern Post-Oak Belt of Texas. Climatic and edaphic factors, relating either directly or indirectly to the amount of moisture available for tree use, explained up to 17% of height growth variation. Height growth of the plantations was comparable to that of plantations growing in the pine-mixed hardwood forest cover type of East Texas. The Northern Post-Oak Belt of Texas is an area approximately 50 to 100 miles wide located between the pine-mixed hardwood forest type to the east and the blackland prairie to the west. Soils within the belt belong primarily to the Alfisol or Ultisol soil orders. The western-most areas of the belt receive up to 20% less annual rain fall than the pine-mixed hardwood type of East Texas (U.S. Environmental Data and Information Service 1949-1982). The present forest of this area is dominated by post oak (Quercus stellate Wang.), blackjack oak (Quercus Marilandica Muench.), blue jack oak (Quercus incana Bartr.), and black hickory (Carya texana Buckl.) (Ward 1984). Loblolly pine (Pinus taeda L.) and shortleaf pine (Pinus echinata Mill.) occur naturally only in scattered locations (Wilson and Hacker 1986). South. j. Appl. For. 13(1):5-8

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

Aim of 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 PalenciaMaterial 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.Keywords: C stocks; pine; Quercus pyrenaica; litter; metabolic quotient (qCO2)

Northern red oak regeneration in oak and pine stands : long-term effects of mechanical competitor removal and short-term effects of prescribed fire

Northern red oak (Quercus rubra) stands in northern lower Michigan are maturing on intermediate quality sites formerly dominated by mixed red pine (Pinus resinosa) and white pine (Finns strobus) forests. White pine and red maple (Acer rubrum) regeneration has been more prevalent than oak regeneration in oak stands throughout several forest regions of eastern North America. It has been hypothesized that the absence of wildland fire is supporting greater components of red maple in the present oak/pine stand type than in presettlement stands. Maintaining the current oak resource has become a priority for forest managers, in Michigan and elsewhere, due to the high wildlife and timber values oak provides. Factors such as canopy composition, cover, and fire may influence oak regeneration by affecting red maple competition, late spring frosts, and deer browsing. Questions need to be addressed regarding effects of specific treatments on oak regeneration success in regions where hardwoods did not dominate historically. Objectives included: 1) Testing the hypothesis that prescribed burning will reduce the abundance and cover of red maple and other competitors relative to oak, 2) Testing the hypothesis that oak seedling pre-hum height and/or basal diameter can be used to predict post-hum sprout growth, and 3) Investigating effects of interactions between prescribed fire and forest cover type (oak vs. pine), canopy cover, and deer browsing on oak and competitors of oak. Study sites consisted of three natural northern red oak stands and three red pine plantations. Overstory removal treatments and understory manipulations were completed in 1991, when northern red oak acorns and nursery seedlings were planted with and without protection from browsing. Natural regeneration and planted oaks were measured and evaluated for growth and mortality July through August, in 2001 and 2002, before and after prescribed burning. One decade after initial treatment, before prescribed burning, red maple density was already significantly less abundant in pine stands compared to oak stands. Mortality of planted oak seedlings was greatest in pine clearcuts and lowest in plots originally thinned to 75% canopy cover plots within pine stands. Caged seedlings exhibited greater survival in pine stands while uncaged seedling survival was nearly equal between cover types. Natural oak regeneration was significantly most abundant in plots originally thinned to 25% canopy cover plots within oak stands. Prescribed fire was applied across all replicates in May, 2002. Following burning, the 25% canopy treatment within oak stands maintained significantly more oak stems than all other treatments. Post-bum oak sprout growth was greatest in clear-cut and 25% cover plots. Nearly all red maple \u3c 2m tall were top-killed, while many larger maple sustained bark damage and infection by pathogenic fungi. These stressed stems sprouted prolifically even though the main stem survived. A noticeable increase in deer browsing of red maple compared to previous years was documented. Following burning, the percentage of uncaged oak seedlings browsed decreased in all plots within oak stands and increased in pine shelterwood plots. Results indicated that, on intermediate sites, a pine canopy had more negative effects on red maple development than did a single prescribed fire. Therefore, prescribed burning to control understory competitors was less critical in pine than in oak stands on these sites. The results also suggested that prescribed fire use is most successful for maximizing oak regeneration in oak shelterwood stands with 25-50% canopy cover, where oak regeneration was present before buming. First year fire effects indicated that red maple control was most successful in uncut plots. Future sampling will be needed to determine the effect fire had on larger red maple saplings in clear-cuts and 25-50% canopy cover treatments

Runoff and erosion generation by simulated rainfall in a Mediterranean forest with forest management

Introduction: Forest management is necessary for forest conservation and the security of natural assets and people; however, forest management can have negative effects on some soil properties. Objective: To determine whether forest management in a Mediterranean forest basin, consisting of Quercus suber L. and Pinus halepensis Mill., causes increased runoff and eroded material at slope level. Materials and methods: Seven land-use units were selected: a) dense forest (no management); b) recently managed cork oak forest, c) recently managed pine forest; d) cork oak forest with two years of management, e) pine forest with two years of management, f) bare terrain with herbaceous vegetation and (g) a forest road. In each area, four rainfall simulations were carried out from a height of 2 m, at a pressure of 1.7 kg·cm -2 , equivalent to a rainfall intensity of 60 mm·h -1 . An ANOVA was performed and significant differences were verified (post-hoc Tukey test, P < 0.05). Results and discussion: The forest road and the bare terrain, areas devoid of vegetation, produced more runoff (4 to 12 %) than more vegetated areas (<1 %). The forest road recorded significantly higher erosion values (96 g·m -2 ) than the other land uses (<4 g·m -2 ) Conclusion: There is no difference in the generation of runoff and erosion in the managed areas, both pine and cork oak, compared to dense or unmanaged forest

Faunistical and Ecological Studies on Carabid Beetles

In this paper on the distribution of carabids at high altitudes, the effect of Nature 2000 habitat and landform types in driving ground beetle (Carabidae) distribution at high altitudes in the Western Dolomites (Brenta group, Italy) was studied. Papers studying carabid beetles in forested habitats investigated the effect of different stand composition (pure oak stands, oak–pine mixed stands, single tree admixtures of oak in pine stands, and pure pine stands) on the abundance and spatial distribution of large-sized Carabus species, as well as the effect of forest type (broad-leaved deciduous forests vs. coniferous plantations) on the diversity and community composition of ground beetles; furthermore, the effect of various forest edges (natural vs. anthropogenic edges) on the abundance of ground beetles of different habitat affinity and dispersal power was examined. The paper on predation pressure aimed to explore the predation pressure on carabids using 3D-printed decoys installed in two types of forestry treatments, preparation cuts and clear cuts, and control plots in an oak–hornbeam forest