共查询到20条相似文献，搜索用时 15 毫秒
1.
Saproxylic beetles are highly sensitive to forest management practices that reduce the abundance and variety of dead wood. However, this diverse fauna continues to receive little attention in the southeastern United States even though this region supports some of the most diverse, productive and intensively managed forests in North America. In this replicated three-way factorial experiment, we investigated the habitat associations of saproxylic beetles on the coastal plain of South Carolina. The factors of interest were forest type (upland pine-dominated vs. bottomland hardwood), tree species (Quercus nigra L., Pinus taeda L. and Liquidambar styraciflua L.) and wood posture (standing and downed dead wood, i.e., snags and logs). Wood samples were taken at four positions along each log and snag (lower bole, middle bole, upper bole and crown) ∼11 months after the trees were killed and placed in rearing bags to collect emerging beetles. Overall, 33,457 specimens from 52 families and ≥250 species emerged. Based on an analysis of covariance, with surface area and bark coverage as covariates, saproxylic beetle species richness differed significantly between forest types as well as between wood postures. There were no significant interactions. Species richness was significantly higher in the upland pine-dominated stand than the bottomland hardwood forest, possibly due to higher light exposure and temperature in upland forests. Although L. styraciflua yielded more beetle species (152) than either Q. nigra (122) or P. taeda (125), there were no significant differences in species richness among tree species. There were also no relationships evident between relative tree abundance and observed or expected beetle species richness. Significantly more beetle species emerged from logs than from snags. However snags had a distinct fauna including several potential canopy specialists. Our results suggest that conservation practices that retain or create entire snags as opposed to high stumps or logs alone will most greatly benefit saproxylic beetles in southeastern forests. 相似文献
2.
Conserving saproxylic beetles in temperate forests will require a better understanding of habitat requirements. So far, quantitative community studies have rarely considered their vertical requirements. In comparison with the tropical forest canopy, it remains to be seen whether a comparably high level of beetle diversity exists in the temperate forest canopy.We compared saproxylic beetle assemblages at two vertical levels in three temperate French forests. Two datasets originated from emergence traps of pine and oak deadwood substrates (mid-canopy and forest floor branches) in lowland forests. The third compared flying beetle fauna at mid-canopy and understory levels using pairs of flight interception traps in beech-fir mountain forests.Our study provided contrasting results regarding the contribution of each stratum to biodiversity. Whereas higher abundance and species richness were apparent in understory samples in beech-fir stands and in oak branches, no difference for richness - or even the opposite pattern for abundance - was observed in pine branches. A significant inter-strata dissimilarity was revealed in all datasets. Each stratum harbored specialist taxa. Exclusive canopy species accounted for 20-40% of all species. In accordance with dissimilarity partitioning, arboreal saproxylic beetle communities were not just nested subsets of ground assemblages.It is likely that microhabitat requirements, food availability and other non-resource-based factors (microclimate preference, species interactions) drive the stratification of beetle assemblages.Our results lend support (i) to the recommendation of a multi-strata sampling strategy for forest insects and (ii) to management practices in favour of valuable canopy micro-habitats. 相似文献
3.
Ángela Taboada Reyes Tárrega Leonor Calvo Elena Marcos José Antonio Marcos José María Salgado 《European Journal of Forest Research》2010,129(1):31-45
The aim of this study was to evaluate the influence of forest structure (mainly resulting from human uses) and forest type (the identity of the dominant tree species) on biodiversity. We determined the diversity of two taxonomical groups: the understory vegetation and the edaphic carabid beetle fauna. We selected eight types of forest ecosystems (five replicates or stands per forest type): pine (Pinus sylvestris) plantations of three age classes (10, 40 and 80 years since reforestation), an old-growth relict natural pine forest, and four types of oak (Quercus pyrenaica) stands: mature forests with livestock grazing and firewood extraction, mature forests where uses have been abandoned, “dehesa” ecosystems and shrubby oak ecosystems. The results obtained by a global PCA analysis indicated that both tree size and dominant species influenced the ordination of the 40 forest stands. In general, carabids were more sensitive to changes in forest heterogeneity and responded more clearly to the analysed structural variables than the understory vegetation, although the species richness of both groups was significantly correlated and higher in case of oak forests. Pine forest ecosystems were characterised by the lowest species richness for both taxonomical groups, the lowest plant diversity and by the lowest coefficients of variation and, consequently, low structural heterogeneity. As a result, it was very difficult to discriminate the effects of the spatial heterogeneity and the dominant tree species on biodiversity. 相似文献
4.
《Forest Ecology and Management》2006,227(3):195-206
From 1920 to 1989, approximately 847,000 ha of Alaska spruce (Picea spp.) forests were infested by spruce beetles (Dendroctonus rufipennis). From 1990 to 2000, an extensive outbreak of spruce beetles caused mortality of spruce across 1.19 million ha of forests in Alaska; approximately 40% more forest area than was infested the previous 70 years. This review presents some of the most important findings from a diversity of research and management projects from 1970 to 2004 to understand the biology, ecology, and control of this important forest insect, and the causes and effects of their outbreaks. We suggest that future research should examine the long-term effects of the spruce beetle outbreaks and climate variability on forest ecosystems in the region. Research into how different management actions facilitate or interrupt natural successional processes would be particularly useful. 相似文献
5.
Effects of reforestation by native tree species on species assemblages of carabid beetles were studied between 40-year-old regenerating plantations and 100-year naturally regenerated forests in Southwestern China. Two old naturally regenerated forest types (ca.100 years old) were chosen: hemlock-spruce forests (Tsuga chinensis and Picea brachytyla) and birch forests (Betula albo-sinensis). Three young regenerating forest types (ca. 40 years old), including spruce plantations (P. brachytyla), larch plantations (Larix kaempferi and Larix mastersian), and natural broad-leaved forests, were established after the logging of the old naturally regenerated forests. Using pitfall traps, we compared the distribution of carabid beetles in the five forest types. Three replicated plots for each forest type were chosen, and each plot was investigated with four trap sites twice each month during the growing season (May to October) in 2004. Our results showed that species richness and abundance were significantly higher in the young regenerating forests than in the old naturally regenerated forests. Analysis of complementarity in carabid species lists across the forest ages and types showed that the old naturally regenerated birch forests had the lowest similarity with the young regenerating larch plantations, and the highest similarity was shown between the two young regenerating plantations. Although PCoA ordination grouped the carabid assemblages according to forest type and forest age, the overall similarity among all forest types was high. Moreover, quantitative character species analysis did not detect significant species associated with forest types and ages. Based on the specificity and fidelity, most carabid species were abundant in all habitats, and only a few species were restricted in one or two forest types. Multiple linear regression between the species richness, abundance and Shannon diversity of carabids and of five environmental variables showed that the cover of canopy and herbaceous layer, and the depth of leaf litter had significant effects in determining richness, abundance and diversity of carabid beetles. Thus, the young regenerating forests at the mature stage could provide an appropriate habitat for most forest species of carabids survived in adjacent old naturally regenerated forests and might replace the role in part of the old-growth forests in sustaining the diversity of carabid assemblages. But some species are still restricted in old naturally regenerated forests, so in order to protect the diversity of carabid assemblages, it is necessary to sustain the intact old naturally regenerated forests when reforesting with some native tree species following natural succession. 相似文献
6.
Paul Van de Wouw Cristian EcheverríaJosé María Rey-Benayas Milena Holmgren 《Forest Ecology and Management》2011,262(6):1100-1108
Mediterranean ecosystems are global hotspots of biodiversity threaten by human disturbances. Growing evidence indicates that regeneration of Mediterranean forests can be halted under certain circumstances and that successional stages can become notoriously persistent. The Mediterranean sclerophyllous forest in central Chile is been largely transformed into savannas dominated by the invasive legume tree Acacia caven as result of interacting management and ecological factors. We used multi-temporal satellite imagery to study the transition dynamics of these major vegetation types over the last four decades (1975-2008). Vegetation changes were related to indicators of resource availability (topography, water availability, solar radiance), potential propagule availability (distance to forest remnant patches) and disturbance regimes (grazing, fire occurrence and distance to roads and cities). During this study period, forests were mostly converted into Acacia savannas (46.1%). Acacia savanna was the most persistent natural vegetation type. The probability of sclerophyllous forest degradation into Acacia savanna increased on drier northern-exposed slopes, close to roads and further away from forest remnants. In contrast, forest regeneration from Acacia savanna was higher on moister southern-exposed slopes and closer to forest remnants. Acacia savannas are increasingly being converted into cultivated land on the moister locations or switching into a bare soil state in locations close to cities and further away from forest remnants. These results highlight the vulnerability of diverse sclerophyllous forests and its increasing conversion into persistent Acacia savannas in the Mediterranean region of central Chile and identify the ecological conditions for successful conservation and restoration of the native sclerophyllous forest vegetation that can be used for sensible land use planning. 相似文献
7.
Pinus sylvestris-dominated forests have been heavily utilized across all of boreal Fennoscandia and the remaining natural forests are generally highly fragmented. However, there are considerable local and regional differences in the intensity and duration of past forest utilization. We studied the impact of human forest use on the diversity of epiphytic and epixylic lichens in late-successional Pinus sylvestris-dominated forests by assessing species richness and composition along both local and regional gradients in forest utilization. The effects of local logging intensity were analysed by comparing three types of stands: (i) near-natural, (ii) selectively logged (in the early 20th century) and (iii) managed stands. The effects of regional differences in duration and intensity of past forest use were analysed by comparing stands in two contrasting regions (Häme and Kuhmo–Viena). The species richness of selectively logged stands was as high as that of near-natural stands and significantly higher in these two stand categories than in managed stands. Species richness increased with the density of small understorey Picea, which correlated strongly with decreasing intensity of local forest use and increasing structural complexity of selectively logged and near-natural stands. Stands in the Häme region hosted a lower number of species, and were less likely to host many old-growth indicator species than the Kuhmo–Viena region, suggesting that species have been lost from stands in the Häme region due to a longer history of intensive forest use. We conclude that selectively logged stands, along with near-natural stands, are valuable lichen habitats particularly for species confined to old-growth structures such as coarse trees and deadwood. In landscapes where natural forests have become fragmented, the management or restoration of the remaining late-successional Pinus-dominated forests, e.g. through the use of fire, should be carefully planned to avoid adverse effects on lichen species richness. 相似文献
8.
《Forest Ecology and Management》2006,227(3):219-232
When spruce beetles (Dendroctonus rufipennis) thin a forest canopy, surviving trees grow more rapidly for decades until the canopy closes and growth is suppressed through competition. We used measurements of tree rings to detect such growth releases and reconstruct the history of spruce beetle outbreaks at 23 mature spruce (Picea spp.) forests on and near the Kenai Peninsula, Alaska and four mature white spruce (Picea glauca) forests in Kluane National Park and Reserve, Yukon Territory. On the Kenai Peninsula, all stands showed evidence of 1–5 thinning events with thinning occurring across several stands during the 1810s, 1850s, 1870–1880s, 1910s, and 1970–1980s, which we interpreted as regional spruce beetle outbreaks. However, in the Kluane region we only found evidence of substantial thinning in one stand from 1934 to 1942 and thinning was only detected across stands during this same time period. Over the last 250 years, spruce beetle outbreaks therefore occurred commonly among spruce forests on the Kenai Peninsula, at a mean return interval of 52 years, and rarely among spruce forests in the Kluane region where cold winter temperatures and fire appear to more strongly regulate spruce beetle population size. The massive 1990s outbreaks witnessed in both regions appeared to be related to extremely high summer temperatures. Recent outbreaks on the Kenai Peninsula (1971–1996) were positively associated with the 5-year backwards running average of summer temperature. We suggest that warm temperature influences spruce beetle population size through a combination of increased overwinter survival, a doubling of the maturation rate from 2 years to 1 year, and regional drought-induced stress of mature host trees. However, this relationship decoupled after 1996, presumably because spruce beetles had killed most of the susceptible mature spruce in the region. Thus sufficient numbers of mature spruce are needed in order for warm summer temperatures to trigger outbreaks on a regional scale. Following the sequential and large outbreaks of the 1850s, 1870–1880s, and 1910s, spruce beetle outbreaks did not occur widely again until the 1970s. This suggests that it may take decades before spruce forests on the Kenai Peninsula mature following the 1990s outbreak and again become susceptible to another large spruce beetle outbreak. However, if the recent warming trend continues, endemic levels of spruce beetles will likely be high enough to perennially thin the forests as soon as the trees reach susceptible size. 相似文献
9.
通过对云南省滇中地区云南松天然林和人工林的群落结构调查及物种多样性研究,结果表明:干扰较少的云南松天然林具有较为稳定、合理的群落结构,其乔木层优势种群具有较强的自然更新能力和长远的演替潜力,并且物种多样性和生境多样性。干扰较少的云南松天然林的这些特性均优于干扰较大的云南松天然林,干扰较大的云南松天然林又优于人工林。随着森林起源过程中干扰(人为干扰和自然干扰)程度的逐渐增加,云南松群落的稳定性、生物多样性、协调平衡能力及自然修复能力相应下降;而入侵种紫茎泽兰的分布范围和数量则相应上升,提示其或可作为森林群落生物多样性、干扰程度和森林健康评价的指示生物。 相似文献
10.
Kamal J.K. Gandhi Daniel W. Gilmore Steven A. Katovich William J. Mattson John C. Zasada Steven J. Seybold 《Forest Ecology and Management》2008
We studied the short-term effects of a catastrophic windstorm and subsequent salvage-logging and prescribed-burning fuel-reduction treatments on ground beetle (Coleoptera: Carabidae) assemblages in a sub-boreal forest in northeastern Minnesota, USA. During 2000–2003, 29,873 ground beetles represented by 71 species were caught in unbaited and baited pitfall traps in aspen/birch/conifer (ABC) and jack pine (JP) cover types. At the family level, both land-area treatment and cover type had significant effects on ground beetle trap catches, but there were no effects of pinenes and ethanol as baits. Six times more beetles were trapped in the burned forests than in the other land-area treatments; more beetles were caught in undisturbed than in wind-disturbed sites, and one-third more beetles were caught in the ABC than in the JP cover type. Thus, the windstorm generally reduced the activity-abundance of the beetles, but prescribed-burning increased it. Both salvaged and burned forest plots (especially in the ABC cover type) had the greatest species richness, diversity, and the most unique species assemblages. There was a highly similar ground beetle species composition (nearly 100%) between the ABC and JP burned forests, indicating that burning was a more primary driver of composition than cover type. At the species level, Pterostichus melanarius, an invasive ground beetle from Europe and a cover type generalist, was the most abundant beetle in the study (one-third of the total catch), and was caught in greatest numbers in burned forests. Removal of P. melanarius from the species composition analyses altered similarities among cover types and land-area treatments. Sphaeroderus nitidicollis brevoorti and Myas cyanescens were caught exclusively in the ABC and JP cover type, respectively; two rare pyrophilous species, Sericoda obsoleta and Sericoda quadripunctata, were only caught in burned sites; three forest species, Pterostichus coracinus, P. pensylvanicus, and Sphaeroderus lecontei, were caught more often in undisturbed JP sites; and two frequently trapped, open-habitat species, Agonum cupripenne and Poecilus l. lucublandus, were nearly absent from the undisturbed and wind-disturbed sites, as salvage-logging had a significant positive effect on their activity-abundance. Most species of Amara and Harpalus were trapped only in the salvaged or burned sites, indicating invasion of these disturbed sites by open-habitat species. We conclude that both the combined effect of fuel-reduction activities subsequent to the wind event and the numerical response of the invasive P. melanarius to habitat disturbances can alter the short-term succession of ground beetle assemblages in the sub-boreal forest. 相似文献
11.
Worldwide, the land area devoted to timber plantations is expanding rapidly, especially in the tropics, where reptile diversity is high. The impacts of plantation forestry and its management on native species are poorly known, but are important, because plantation management goals often include protecting biodiversity. We examined the impact of pine (Pinus caribaea) plantations, and their management by fire, on the abundance and richness of reptiles, a significant proportion of the native biodiversity in tropical northern Australia, by (i) comparing abundance and diversity of reptiles among pine plantations (on land cleared specifically for plantation establishment), and two adjacent native forest types, eucalypt and Melaleuca woodlands, and (ii) comparing reptile abundance and richness in pine forest burnt one year prior to the study to remove understorey vegetation with pine forest burnt two years prior to the study. We also examined the influence of fire on reptile assemblages in native vegetation, by comparing eucalypt woodland burnt two years prior to the study and unburnt for eight years. To quantify mechanisms driving differences in reptile richness and abundance among forest types and management regimes, we measured forest structure, the temperatures used by reptiles (operative temperature) and solar radiation, at replicate sites in all forest types and management regimes. Compared to native forests, pine forests had taller trees, lower shrub cover in the understorey, more and deeper exotic litter (other than pine), and were cooler and shadier. Reptile assemblages in pine forests were as rich as those in native forests, but pine assemblages were composed mainly of species that typically use closed-canopy rainforest and prefer cooler, shadier habitats. Burning did not appear to influence the assemblage structure of reptiles in native forest, but burning under pine was associated with increased skink abundance and species richness. Burned pine was not warmer or sunnier than unburned pine, a common driver of reptile abundance, so the shift in lizard use after burning may have been driven by structural differences in understorey vegetation, especially amounts of non-native litter, which were reduced by burning. Thus, burning for management under pine increased the abundance and richness of lizard assemblages using pine. Pine plantations do not support the snake diversity common to sclerophyllous native forests, but pine may have the potential to complement rainforest lizard diversity if appropriately managed. 相似文献
12.
Plantation forests are an important part of the forest estate in many countries. In Ireland, they cover around 9% of the land area and many that are commercially mature are now being felled and reforested. The potential biodiversity value of such second rotation forests has yet to be determined, yet this may be particularly significant in Ireland where cover of semi-natural woodland is only 1%. Invertebrates are a vital component of forest biodiversity, functioning as decomposers and pollinators, herbivores, predators and prey. Spiders and Carabid beetles are often used in biodiversity assessment as they are easily captured using pitfall traps, are taxonomically well known and respond to changes in habitat structure. This study aimed to examine spider and Carabid beetle diversity in second rotation Sitka spruce (Picea sitchensis) plantations at different stages of the forest cycle (5, 8–12, 20–30, 35–50 years), and compare the spiders captured in second rotation forests with those from first rotation. Spider and beetle diversity was influenced by stand structural development in second rotation plantations with numbers of forest-associated species increasing over the forest cycle. Overall, spider richness declined over the forest cycle and this was related to decreasing cover of field layer vegetation and fewer open-associated species. In contrast, total beetle richness increased and became more specialised over the forest cycle which may be related to slower colonisation of disturbed areas by beetles in comparison with spiders, and fewer open specialists at the early stages of second rotation. Spider assemblages were distinguished between rotations. This may be related to differing habitat conditions in second rotation forests including dryer soils with lower pH, differing vegetation complexity and presence of brush piles. Few of the forest species accumulated during first rotation were retained and the early stages of second rotation forest cycle was characterised by a generalist open fauna. Nonetheless, as the forest cycle progressed the spider assemblages between rotations became more similar. Current forest policy supports retaining over-mature trees and creating a mosaic of different aged stands within a plantation. Such measures may provide refuge for forest species after clearfell. In countries where forest fragments exist in a landscape dominated by agriculture, consideration should be given to the capacity of mature forest adjacent to felled stands to support forest species, and to the configuration of over-mature areas retained after felling. 相似文献
13.
Pine honeydew honey is an economically important non-wood forest product from eastern Mediterranean Pinus brutia forests, which are also important for timber production. Pine honey is produced by bees that feed on the honeydew secretions of Marchalina hellenica, a scale insect that infests pine stands and feeds on pine sap. The aim of this study was to optimize the joint production of pine honeydew honey and timber by maximizing the soil expectation value of pine stands. The simulation of P. brutia stand dynamics and timber production in healthy and infested stands is based on individual-tree growth and yield models that account for the effect of M. hellenica on tree- and stand-level growth and mortality. The optimization procedure uses a direct search method based on nonlinear programming. The results suggest that pine stands growing on good sites should be managed using rather short rotations and mainly aiming at timber production. In contrast, forest management in medium- and poor-quality sites should aim at longer rotations by taking advantage of the joint production of pine honey and timber assortments. Honey-oriented forest management can be much more profitable than timber production in stands growing on medium and poor sites. Pine honey represents an opportunity to increase the value and economic profitability of P. brutia forests. 相似文献
14.
Leaf Area Index (LAI) is a main variable controlling carbon and water fluxes. This paper estimated the effect of thinning on the spatial distribution of leaf area in French forests. While many studies have focused on average LAI, we estimated clumping and measured both average LAI and the variation around it. LAI was derived from digital hemispherical photos at three sites: an unmanaged Fagus sylvatica forest in temperate area (control site), a mixed Mediterranean forest of Quercus ilex and Pinus halepensis, and regeneration of F. sylvatica under a mature stand of Pinus nigra in mountainous area. LAI measurements were also made with LAI 2000 devices over 5 years (from 1994 to 1998) within forest stands dominated by either beech (F. sylvatica L.), by oaks (Quercus petraea (Matus) Liebl., Quercus robur (Matus) Liebl.), or by Scots Pine (Pinus sylvestris L.). Thinning led to a variable decrease in LAI. The coefficient of variation of LAI (CVLAI) provided a useful ecological index of the level and type of thinning. For undisturbed stands, CVLAI varied from 10% to 20%, corresponding to the higher average LAI values. Disturbances created by thinning increase LAI spatial variability, resulting in larger CVLAI values for all stands considered. Possible explanations of these results and use in remote sensing were discussed. 相似文献
15.
Ecological investigation of the distribution and composition of dung beetle species utilizing feces of wild mammals has rarely
been attempted, especially in cool-temperate forests. In this study we recorded and evaluated the community structure of dung
beetle species utilizing feces of Japanese monkeys (Macaca fuscata) by conducting a macro-scale inventory survey in the northeastern Shirakami Mountains, located in the northernmost part of
mainland Japan. Moreover, to assess the effect of human-induced forest disturbance on species assemblages in this cool-temperate
area, we also carried out field sampling using pitfall traps baited with monkey feces in primary forests, secondary forests,
and coniferous plantations, during every season except winter. Our findings were: (1) 14 dung beetle species comprising eight
dwellers and six tunnelers utilized monkey feces; (2) Aphodius eccoptus was the core species in dung beetle assemblages attracted to the feces during spring and summer; (3) the frequency of occurrence
of every species was extremely high in spring; and (4) human-induced forest disturbance did not increase species richness
or biomass in cool-temperate forests. 相似文献
16.
Key message
Carbon stock density was quite similar in planted vs natural forest of Masson’s pine ( Pinus massoniana Lamb.) in China across three ages (7, 15, and 50 years). The stock in the standing trees was larger in planted than in natural forests, but this difference was compensated by larger stocks in the soil and the debris of natural forests.Context
Most studies on the carbon stocks are focused on management strategies to maximize carbon stocks. We still lack data comparing planted vs natural conifer forests.Aims
We compared carbon storage in the different compartment (vegetation, soil, debris) along a chronosequence of Masson’s pine plantations vs natural forests.Methods
We investigated 58 Masson’s pine (Pinus massoniana Lamb.) forest stands (20 m?×?50 m plots), that differ in stand management (planted and natural forests) and age (young, middle-aged, and mature ages) and then calculated the carbon stock densities of vegetation biomass (tree, shrub, and herb), debris, and soil.Results
The carbon stock densities in the planted and natural Masson’s pine forest ecosystems ranged from 78 to 210 Mg ha?1 and from 97 to 177 Mg ha?1 respectively. The carbon stock densities in the vegetation were significantly greater in planted forests than in natural forests. A lower carbon stock density in debris and soil alleviated the increase of biomass carbon stock densities in planted vs natural forests, leading to similar carbon stock densities at ecosystem level. The carbon stock densities in the vegetation increased with age, whereas those of debris and soil remained stable.Conclusions
Planted forests of Masson’s pine sequester similiar amounts of carbon at ecosystem level to those in natural forests, reinforcing the idea that planted pine forests can contribute to the mitigation of greenhouse gas emission.17.
The frequency and intensity of ecosystem disturbance, including outbreaks of forest insects and forest fires, is expected to increase in the future as a result of higher temperatures and prolonged drought. While many studies have concentrated on the future climatic impacts on fire, little is known about the impact of future climate on insect infestation. Paleoecological techniques are important in this regard in identifying the potential relationships between climate and insect outbreaks in the past, as a predictive tool for the future. We examine a high-resolution 20th century record of spruce beetle (Dendroctonus rufipennis) infestation from a small, subalpine lake, comparing the paleoecological record to the historical and tree-ring record of the event. An extensive spruce beetle outbreak occurred in northwestern Colorado during the 1940s and 1950s, causing widespread mortality of mature Picea engelmannii. Pollen analysis of this period documents the decline of Picea and its replacement locally by Abies lasiocarpa, paralleling age and composition studies of modern forest stands in the region. This study is a proof of concept that, when applied to longer sedimentary records, could produce a detailed record of infestation for the Late Holocene or older time periods. This information will be useful to forest managers in efforts to plan for the effects of D. rufipennis infestations, and subsequent succession within high elevation conifer forests. 相似文献
18.
In Korea, damaging typhoons related to climate change have increased steadily since the 1990s. Red pine (Pinus densiflora) forests in Gwangneung Forest were greatly disturbed by typhoon Kompasu in 2010. A survey was carried out to clarify differences in ground beetle (Coleoptera: Carabidae) communities between forest gaps and undamaged forests. Ground beetles were sampled using pitfall traps from early May to late October 2011. Vegetation changes, litter layer, organic matter layer, and soil conditions were also measured. A total of 1035 ground beetles of 32 species were collected. Contrary to our expectation, species richness, abundance, and community structure of the ground beetles in forest gaps were similar to those in undamaged forests. Species richness and abundance of habitat type were also similar. However, species diversity and estimated species richness in forest gaps were significantly higher than in undamaged forests. These findings suggest that forest gaps formed by a typhoon did not lead to great change in ground beetle communities. 相似文献
19.
《Forest Ecology and Management》2005,211(3):264-295
During the last centuries forest management has changed the structure and species composition of central European forests. One option to assess forest management and how management impacts may affect forest development over time is the use of biogeochemical ecosystem simulation models. They integrate key ecosystem processes and have proven to be an appropriate diagnostic tool. If we consider that in the past, forest management has strongly affected the species distribution and the structure of central European forests, existing biogeochemical models need to integrate species-specific parameters so that they can adequately address forest management practices such as species changes, stand density etc. The purpose of this paper is to introduce species-specific parameters for one such model, Biome-BGC, for the following tree species as observed in central European forests: Fagus sylvatica, Quercus robur/petraea, Larix decidua, Pinus sylvestris, Pinus cembra as well as two sets of parameters for Picea abies growing at low and high elevations. We first evaluate and test model results obtained with parameters from the literature and single research plots. This evaluation procedure gives our final species-specific parameters that are then used in the model. Next we validate the quality of the model predictions using these parameters versus field observations covering the growing range of a given species by comparing standing tree volume, volume increment, soil carbon and soil nitrogen on 145 independent plots. Our results demonstrate that the species-specific parameters yielded consistent and unbiased predictions. 相似文献
20.
Tree regeneration and future stand development after bark beetle infestation and harvesting in Colorado lodgepole pine stands 总被引：1，自引：0，他引：1
Byron J. CollinsCharles C. Rhoades Robert M. HubbardMichael A. Battaglia 《Forest Ecology and Management》2011,261(11):2168-2175
In the southern Rocky Mountains, current mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreaks and associated harvesting have set millions of hectares of lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.) forest onto new stand development trajectories. Information about immediate, post-disturbance tree regeneration will provide insight on dynamics of future stand composition and structure. We compared tree regeneration in eight paired harvested and untreated lodgepole pine stands in the Fraser Experimental Forest that experienced more than 70% overstory mortality due to beetles. New seedlings colonized both harvested and untreated stands in the first years after the beetle outbreak. In harvested areas the density of new seedlings, predominantly lodgepole pine and aspen, was four times higher than in untreated stands. Annual height growth of pine and fir advance regeneration (e.g., trees established prior to the onset of the outbreak) has doubled following overstory mortality in untreated stands. Growth simulations based on our regeneration data suggest that stand basal area and stem density will return to pre-beetle levels in untreated and harvested stands within 80-105 years. Furthermore, lodgepole pine will remain the dominant species in harvested stands over the next century, but subalpine fir will become the most abundant species in untreated areas. Owing to terrain, economic and administrative limitations, active management will treat a small fraction (<15%) of the forests killed by pine beetle. Our findings suggest that the long-term consequences of the outbreak will be most dramatic in untreated forests where the shift in tree species composition will influence timber and water production, wildfire behavior, wildlife habitat and other forest attributes. 相似文献