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1.
The vegetation dynamics of Korean red pine (Pinus densiflora) forests were investigated at Mt. Seorak, Korea. Our Detrended Correspondence Analysis (DCA) classified the forests into four types: ridge top, upper slope, lower slope/hill, and streamside. The ridge top forests were likely to sustain themselves, as suggested by the large proportion of seedlings and saplings (89% at <25 years old) and the relatively high density ofP. densiflora (2388 stems ha-1). Periodic disturbances, such as flash floods, made the streamside inhospitable to late-successional species. Such conditions may have provided a favorable environment for the recruitment ofP. densiflora seedlings through increased solar radiation and decreased competition with other species. On the upper slopes, the dominance ofQuercus seedlings and saplings (63% at >25 years old, and a density of 3263 stems ha-1) suggests a transition from pine to oak forest. Extensive human interventions appeared to arrest the natural succession from pine to oak forests on the lower slope/hill, while encouraging invasions by forest-edge and introduced species (e.g.,Rosa multiflora andRobinia pseudoacacia).  相似文献   

2.
We studied carabid beetle assemblage structure and species diversity in an intermediate successional stage (seral) forest established in areas affected by the 1888 eruption of Mt. Bandai and a climax forest that had not been affected by the eruption at the Urabandai area, Fukushima Prefecture, Japan. In total, 2,131 carabid beetles representing 31 species were collected using pitfall traps without bait. A comparison of carabid beetle assemblages between the two forest types revealed that the number of species observed was comparable, but their abundance was greater in the seral forest. The assemblage structure clearly differed between the two forest types. In the seral forest, forest generalists, such as Synuchus arcuaticollis and Pterostichus prolongatus, along with forest specialists including Carabus vanvolxemi and Pterostichus asymmetricus, were collected. In the climax forest, forest generalists, such as Synuchus cycloderus and Carabus albrechti tsukubanus, were more abundant than forest specialists. This suggests that the current seral forest in the Urabandai area possesses environmental variables that enable the coexistence of both forest specialist and generalist beetle species. A redundancy analysis showed that six species from the genera Synuchus and Pterostichus were associated with high canopy openness and high understory vegetation cover, whereas species recorded only in the climax forest were associated with deep litter. Therefore, it seems likely that carabid beetles in the Urabandai area were affected by these three environmental variables.  相似文献   

3.
为了探明我国东北阔叶红松(Pinus koraiensis)林地表葬甲多样性及其空间变异特征,在胜山、丰林、凉水和长白山的4个大型森林动态监测样地内,通过布置900个陷阱调查了36 hm2范围内的地表葬甲群落基本特征。基于群落物种数量、个体数量和总体长,分析了地表葬甲多样性及其空间变异性。结果表明:(1)东北阔叶红松林区域物种库包含12个葬甲物种,密度为0.018只/m2,总平均体长达0.32 mm/m2。北方花葬甲(Nicrophorus tenuipes)是东北阔叶红松林内的广布物种,黑葬甲(Nicrophorus concolor)等五个物种具有明显的生境偏好,仅存在于单个局域物种库内。(2)物种数量、个体数量和总体长在胜山、丰林、凉水和长白山样地存在明显差异,其中纬度较低的局域物种库(凉水、长白山)可维持更高的物种多样性,纬度最高的局域物种库(胜山)维持较低的物种多样性。(3)地表葬甲群落在胜山和丰林样地存在显著的空间自相关性,在凉水和长白山样地则不显著。(4)葬甲群落具有较明显的空间异质性,长白山样地的空间变异...  相似文献   

4.
Abstract. The development of secondary Pinus densiflora (Japanese red pine) forests after pine wilt disease was studied through phytosociological analysis, estimation of forest structure before disease and size-structure, tree ring and stem analyses. Following the end of the disease, the growth of previously suppressed small oak trees was accelerated. This is quite different from the development of forests following fire, which starts with the establishment of pine seedlings. Pine wilt disease shifted the dominance of secondary forests from Pinus densiflora to Quercus serrata oak forest. In pine forests, disturbance by fire is important for forest maintenance. In contrast, disturbance by pine wilt disease leads to an acceleration of succession from pine forest to oak forest.  相似文献   

5.
We studied the responses of carabid beetles to Pinus sylvestris ageing in four plantations aged 2–3, 10–12, 40–45 and 80 years, and one mature natural pine forest – in NW Spain. In 2003, a total of 16,866 carabid individuals (50 species) were collected using pitfall traps. Overall carabid abundance and species richness differed significantly among the five age classes with the highest values occurring in the youngest age class. The carabid assemblages of the initial stages of the ageing sequence differed considerably from the later stages that were relatively similar to each other – a consequence of differences in species dominance at specific age classes. Yet, the carabid assemblage of the 80-year-old stage did not approach that of the natural pine forest, but, unexpectedly, the 40–45-year-old age class did. Canopy cover and soil pH were the main environmental variables that affected the carabid distribution. We also detected species-level responses to the ageing process, with open habitat species more abundantly collected at the youngest stages and forest specialists at the older stages. We conclude that carabid beetles responded predictably to the pine plantation ageing process, and that although pine forests in NW Spain do not seem to provide habitat for unique species, they act as secondary habitats for forest specialist species.  相似文献   

6.
The carabid beetle species assemblages (14 sample sites) of a 238 ha urban oak forest in Trieste, Italy, studied in 1983–84 with pitfall traps, were compared with an historic list of 57 species hand collected by entomologists in the same forest before it was logged in 1944.Trap data have been improved by hand collections to get a species list as complete as the historic one. Multivariate analysis was used to group the sites (14 plus the historic list) into three assemblages of brooks, clearings and forests. After the Second World War logging, the secondary ecological succession resulted in a lower species number, with a trend to a new equilibrium. Some important forest specialists, such as Laemostenus venustus, have been lost. Human pressure and recolonisation by carabids are still occurring. The in situ extinction of ground beetles near the end of the last century reached values between 57 and 64% of the species historically recorded. Consequently, urgent restoration measures are required for waterside habitats, forest and land management, to maintain small open areas or clearings. The study of carabid species assemblages and habitat affinities seems a useful tool for adaptive management of forests affected by human activities, because changes in carabid species number and type can be easily related to human disturbance.  相似文献   

7.
In this study, we compared ground-dwelling beetle assemblages (Coleoptera) from a range of different oak fragments and surrounding conifer plantations to evaluate effects of forest size and surrounding matrix habitat in a temperate forest of north China. During 2000, beetles were sampled via pitfall traps within two large oak fragments (ca. 2.0-4.0 ha), two small oak fragments (ca. 0.2-0.4 ha) and two surrounding matrices dom- inated by pine plantations (〉4 ha) in two sites of different aspects. Overall, no significantly negative effects from forest patch size and the surrounding matrix habitat were detected in total species number and abundance of ground-dwelling beetles. However, compared with small oak patches or pine plantations, more species were associated with an affinity for at least one large oak patch of the two aspects. Multivariate regression trees showed that the habitat type better determined the beetle assemblage structure than patch size and aspect, indicating a strong impact of the surrounding matrix. Linear mixed models indicated that species richness and abundance of all ground-dwelling beetles or beetle families showed different responses to the selected environmental variables. Our results suggest that more disturbed sites are significantly poorer in oak forest specialists, which are usually more abundant in large oak fragments and decrease in abundance or disappear in small fragments and surrounding matrix habitats. Thus, it is necessary to preserve a minimum size of forest patch to create conditions characteristic for forest interior, rather than the more difficult task of increasing habitat connectivity.  相似文献   

8.
三种温带森林大型土壤动物群落结构的时空动态   总被引:1,自引:0,他引:1  
李娜  张雪萍  张利敏 《生态学报》2013,33(19):6236-6245
对帽儿山3种典型森林群落大型土壤动物进行了连续6个月的野外调查研究。通过系统分析,共获得大型土壤动物3604只,隶属于3门6纲17目50科。其中正蚓科(Lumbricidae)、线蚓科(Enchytraeidae)和石蜈蚣目(Lithobiomorpha)为优势类群,常见类群11类。结果表明:(1)水平分布上,密度和生物量红松人工林最高,其次为硬阔叶林,蒙古栎林最少;类群数硬阔叶林最多,蒙古栎林最少;香农指数和丰富度指数均为蒙古栎林最高,红松人工林最低;优势度指数与两者相反;均匀度指数蒙古栎林最高,硬阔叶林最低;(2)垂直分布上,个体密度、类群数及生物量均差异显著(P < 0.001)。3个样地大型土壤动物个体密度表聚性明显;类群数红松人工林自凋落物层向下减少,硬阔叶林和蒙古栎林0-10 cm最多;生物量在0-10 cm土层最大;香农指数随深度增加而减小,优势度指数则相反;(3)在时间变化上,5月和10月个体密度和类群数较多,9月生物量最大;香农指数和优势度指数差异显著(P < 0.01),其他指数各月间无明显差异;(4)与土壤环境因子关系上,总有机碳含量与类群数、个体密度及生物量显著正相关,容重与香农指数显著负相关;典型对应分析结果表明,不同类群大型土壤动物与环境相关性不同。  相似文献   

9.
Forest-dwelling carabid beetles that have no flight ability were studied using mark-recapture methods in late-June to mid-October 2007. This study was done to determine the effects of narrow roads in Nopporo Forest Park, Hokkaido on carabid beetle movement and habitat use. The investigation was conducted at four sites: one site was an abandoned grassy road with a width of 3.5 m, two sites were gravel roads with widths of 3.5 and 4.5 m, and another site was an asphalt-paved road with a width of 4.5 m. A total of 3,580 individuals from six species of carabid beetles were collected using dry pit-fall traps, and recapture rates ranged from 6.1 to 36.2%. All examined roads acted as barriers against the movement of Leptocarabus arboreus ishikarinus. All roads, except the abandoned grassy road, acted as a barrier against Carabus granulatus yezoensis movement. Forest–roadside verge comparisons demonstrated that some carabid beetles avoid even narrow roadside verges. Harmful effects increase with increasing road width and both paved roads and narrow roads negatively affect the movement of carabid beetles inhabiting the bordering forest. Therefore, forest specialist beetles are influenced by a barrier effect that starts at the forest road verge, and this barrier effect may be exacerbated by vehicular traffic. Therefore, these barrier effects on carabid beetles should be considered when planning and implementing road construction and maintenance in forests.  相似文献   

10.
Plantation forests are of increasing importance worldwide for wood and fibre production, and in some areas they are the only forest cover. Here we investigate the potential role of exotic plantations in supporting native forest-dwelling carabid beetles in regions that have experienced extensive deforestation. On the Canterbury Plains of New Zealand, more than 99% of the previous native forest cover has been lost, and today exotic pine (Pinus radiata) plantations are the only forest habitat of substantial area. Carabids were caught with pitfall traps in native kanuka (Kunzea ericoides) forest remnants and in a neighbouring pine plantation, grassland and gorse (Ulex europaeus) shrubland. A total of 2,700 individuals were caught, with significantly greater abundance in traps in young pine, grassland and gorse habitats than in kanuka and older pine. Rarefied species richness was greatest in kanuka, a habitat that supported two forest specialist species not present in other habitat types. A critically endangered species was found only in the exotic plantation forest, which also acts as a surrogate habitat for most carabids associated with kanuka forest. The few remaining native forest patches are of critical importance to conservation on the Canterbury Plains, but in the absence of larger native forest areas plantation forests are more valuable for carabid conservation than the exotic grassland that dominates the region.  相似文献   

11.
Red deer (Cervus elaphus) increasing density may trigger several modifications at the ecosystem level. Positive and negative impact of red deer on the invertebrate fauna is known in northern Europe, whereas it is currently unknown in the Alps. In this paper, we tested the impact of red deer density on ground beetles’ (Coleoptera: Carabidae) richness and species distribution in forests of the central-eastern Italian Alps (Stelvio National Park). Carabid beetles were sampled using pitfall traps in nine forest sites with different density of red deer. Carabid species richness was related to elevation, habitat type and red deer density in summer and winter using generalised linear mixed models and canonical correspondence analysis. The high winter red deer density affected positively the carabid species richness. Overgrazing seemed to increase presence of generalist species of dried and unshaded soils and decreasing of specialised species typical of well-preserved Rhododendro-Vaccinietum cover. Accordingly, the presence of patches with different red deer density seems to contribute to maintaining high levels of carabid beetles’ richness, albeit overgrazing needs to be monitored because it is likely to cause a local decrease of specialised forest species.  相似文献   

12.
Abstract: In most temperate deciduous forests, windstorm is the main source of dead wood. However, the effects of this natural disturbance on ambrosia and bark beetle communities are poorly known. In managed oak‐hornbeam forests storm‐damaged in France in 1999, we sampled ambrosia (and second bark beetles) by ethanol‐baited window‐flight traps in 2001. By comparing uncleared gaps, undisturbed closed‐canopy controls and seedling‐sapling stands, we investigated the short‐term effects of gap formation, gap size and surrounding landscape to provide a snapshot of scolytid response. Contrary to expectations, neither the abundance nor the richness of ambrosia beetle species was significantly higher in gaps than in undisturbed stands. Few responses in abundance at the species level and only a slight difference in assemblage composition were detected between gaps and closed‐canopy controls. Gaps were more dissimilar from seedling‐sapling stands, than from closed‐canopy controls. More scolytid individuals and species were caught in gaps than in seedling‐sapling stands. Mean local and cumulative richness peaked in mid‐size gaps. Only mid‐size gaps differed from closed‐canopy controls in terms of species composition. We identified generalist gap species (Xyleborus saxesenii, X. cryptographus), but also species significantly more abundant in mid‐size gaps (Platypus cylindrus, Xyloterus signatus). The faunistic peculiarity of mid‐size gaps seemed to be partly related to a bias in oak density among gap size classes. Few landscape effects were observed. Only the scolytids on the whole and X. dispar were slightly favoured by an increasing density in fellings at the 78 ha scale. We did not find any correlation between scolytid abundance and the surrounding closed‐forest percentage area. We confirmed that temperate, deciduous, managed stands did not come under threat by ambrosia and bark beetle pests after the 1999 windstorm. Nonetheless, our data stressed the current expansion in Western Europe of two invasive species, X. peregrinus and especially X. germanus, now the predominant scolytid in the three oak forests studied.  相似文献   

13.
小兴安岭阔叶红松林地表甲虫Beta多样性   总被引:3,自引:1,他引:2  
Beta多样性用来衡量集群内物种组成的变异性,可以被分解为空间物种转换和物种集群镶嵌两个组分,是揭示群落构建机制的重要基础。目前开展了较多的地上生态系统beta多样性研究,然而地下生态系统beta多样性进展缓慢。以小兴安岭凉水和丰林自然保护区为研究地区,于2015年8、10月采用陷阱法对阔叶红松林进行调查,揭示地表甲虫(步甲科、隐翅虫科、葬甲科)的beta多样性。结果表明:(1)凉水共发现39种、856只地表甲虫,丰林共发现43种、1182只地表甲虫。8月凉水明显具有较高的全部甲虫(三个科的总和)物种多样性和丰富度,10月正好相反。(2)凉水和丰林之间地表甲虫beta多样性的差异仅发现于8月的步甲科和葬甲科之间。(3)凉水和丰林地表甲虫的beta多样性主要由空间物种转换组成,物种集群镶嵌对beta多样性的贡献很小,说明地表甲虫物种组成变异主要由本地物种之间较高的转换引起。研究表明小兴安岭阔叶红松林地表甲虫的beta多样性主要由空间物种转换组成,在揭示群落构建机制过程中,其内部物种交换和环境调控不容忽视。  相似文献   

14.
土壤呼吸是森林生态系统碳循环的关键过程,土壤动物可通过自身代谢及影响微生物活动调控土壤呼吸,因此研究土壤动物与土壤呼吸的相互关系对进一步揭示生态系统碳循环的规律和机理具有重要意义。通过野外定点,以帽儿山3种森林生态系统的土壤呼吸及土壤动物为研究对象,探讨不同森林生态系统的土壤呼吸、土壤动物个体密度和生物量的时间变化规律及二者相互关系。结果表明:(1)3种森林生态系统土壤总呼吸速率与土壤异养呼吸速率均呈现先增强后减弱的时间动态变化(P<0.05),且不同森林生态系统土壤异养呼吸速率差异显著(P<0.05),表现为硬阔叶林最高,红松人工林最低;(2)3种森林生态系统土壤动物生物量也具有显著的时间动态变化(P<0.05),均在9月份达到最大,且不同森林生态系统土壤动物个体密度显著不同(P<0.05),蒙古栎林土壤动物个体密度显著小于红松人工林与硬阔叶林;(3)通过回归分析可得,土壤动物数量及生物量的增加抑制了土壤呼吸速率,尤其在生长季初期、末期。研究表明土壤动物可通过抑制微生物生命活动和降低根系呼吸从而对土壤总呼吸及异养呼吸产生负反馈作用,三者是不可分割的整体,与土壤温度、水分等环境因子共同调控着土壤呼吸。  相似文献   

15.
Abstract: Ponderosa pine (Pinus ponderosa) forests with Gambel oak (Quercus gambelii) are associated with higher bird abundance and diversity than are ponderosa pine forests lacking Gambel oak. Little is known, however, about specific structural characteristics of Gambel oak trees, clumps, and stands that may be important to birds in ponderosa pine-Gambel oak (hereafter pine-oak) forests. We examined associations among breeding birds and structural characteristics of Gambel oak at a scale similar in size to individual bird territories in pine-oak forests in northern Arizona and western New Mexico, USA. Avian species richness and occurrence of some bird species were associated with specific growth forms of Gambel oak. Estimated probability of Virginia's warblers (Vermivora virginiae), black-headed grosbeaks (Pheucticus melanocephalus), and red-faced warblers (Cardellina rubrifrons) occurring at points increased with increasing density of pole-sized Gambel oak 7–15 cm in diameter at breast height. We also found evidence that large Gambel oak trees (≥23 cm dbh) were associated with increased occurrence of yellow-rumped warblers (Dendroica coronata) at points. Some avian associations with oak were influenced by characteristics of ponderosa pines. For example, bird species richness was positively associated with the abundance of large Gambel oak when density of large pine trees ≥23 cm in diameter at breast height was low. Because large oak trees are rare and their numbers are thought to be declining, efforts should be made to retain and promote growth of additional oaks in this size class. Forest management practices that maintain forest openings, such as prescribed burning, could promote growth of pole-sized Gambel oak, which appears important to some bird species in pine-oak forests.  相似文献   

16.
蒙古栎红松林演替模型FOROAK的研究   总被引:2,自引:0,他引:2  
Based on forest dynamics theory, gap model FOROAK was developed for simulating long-termdynamics of Mongolian oak (Quercus rnongolica Fisch. )-Korean pine (Pinus koraiensis Sieb. et Zucc. )forest. The model included two parts: biological growth and environmental impacts on growth. Different areapatches were used in simulating forest changes. The results showed that this forest gap was 0.05 hm2. Themodel testing demonstrated that it could reasonably simulate forest dynamic process, and had a very highaccuracy to predict species compositions. The observed species basal areas was similar to the predicted at 60,100 and 270 year forests, the observed species compositions were similar to the predicted at old forest period.Complex changes were found through modeling forest dynamics of bare ground. Mongolian oak and white birch( Betula platyphylla Sukacz. ) dominated at early stage, forest dominated by broad leaved species was formedat middle stage, and then Korean pine dominated at latter stage. The prediction of current primary forestshowed that it was steady during the next 300 year period, the number of trees and the biomass of Korean pine changed very little.  相似文献   

17.
Theoretical studies of predator‐prey population dynamics have increasingly centered on the role of space and the movement of organisms. Yet, empirical studies have been slow to follow suit. Herein, we quantified the long‐range movement of a checkered beetle, Thanasimus dubius, which is an important predator of a pernicious forest pest, the southern pine beetle, Dendroctonus frontalis. Adult checkered beetles were marked and released at five sites and subsequently recaptured at traps baited with pine and pine beetle semiochemicals and located at distances up to 2 km away from the release point. While the pattern of recaptures‐with‐distance at each site provided a modest fit to a simple random‐diffusion model, there was a consistent discrepancy between observed and expected recaptures: a higher than expected proportion of beetles were recaptured at the more distant traps. To account for this deviation, we developed a model of diffusion that allowed for simple heterogeneity in the population of marked beetles; i.e., a slow and fast moving form of the checkered beetle. This model provided a significantly better fit to the data and formed the basis for our estimates of intra‐forest movement. We estimated that on average, one half of the checkered beetles dispersed at least 1.25 km, one third dispersed>2 km, and 5% dispersed>5 km. The source of the heterogeneous dispersal rates were partially due to differences in beetle size: smaller beetles (for both males and females) were more likely to be recaptured away from the release site than larger beetles. The southern pine beetle (prey for the checkered beetle) exhibited no significant heterogeneity in dispersal ability and provided a very good fit to the simple diffusion model. The only difference in dispersal between these two species was that checkered beetles were undergoing greater long‐distance dispersal than the pine beetles (the radius containing 95% of the dispersing individuals was 5.1 km for the checkered beetle and 2.3 km for the pine beetle). Data on the movement of these two species is used to evaluate a general model of spatial pattern formation in a homogeneous environment, and the potential of the checkered beetle as a biological control agent for the southern pine beetle.  相似文献   

18.
黑龙江省不同地点蒙古栎林生态特点研究   总被引:10,自引:2,他引:8  
通过对黑龙江省6个地点的天然蒙古栎林的结构和更新特点的分析,蒙古栎林可划分为不同特点的蒙古栎群落,即纯蒙古栎群落、蒙古栎桦树群落、蒙古栎槭树群落、蒙古栎红松群落和蒙古栎松混交林群落,其演替趋势如下:红蒙古栎群落、蒙古栎桦树群落至蒙古栎槭树落、蒙古栎红松群落,再至蒙古栎红松混交林群落,蒙古栎群落类型的多样性主要反应群落不同的演替阶段,造成蒙古栎群落多样的原因是人类活动和自然因素作用的结果,随着群落的演替,蒙古栎的优势地位逐渐被消弱,乔木种类丰富度增多,草本种类丰富度增多;蒙栎的相对密度下降,林内环境由于干燥逐渐变中性至较湿润,蒙古栎幼苗和幼树在总幼苗和幼树中所占的比例下降,耐荫物中色木槭等的幼苗和幼树所占比例上升;在演替过程中,蒙古栎分布格局-聚集分布的聚集程度逐渐降低,并向随机分布的方向发展。  相似文献   

19.
蒙古栎红松林演替模型FOROAK的研究   总被引:3,自引:0,他引:3  
以森林动态斑块理论为基础建立了蒙古栎(QuercusmongolicaFisch.)红松(PinuskoraiensisSieb.etZucc.)林动态变化的林窗模型FOROAK,该模型包括对树木生长的生物学过程和影响树木生长的环境因子模拟两部分。用两种不同面积大小的样地分析森林动态,确定蒙古栎红松林林窗面积为0.05hm2。以实际调查数据检验模型,证明所得模型能合理预测森林变化过程,在预测树种组成上精度很高,实际调查和预测的树种断面积组成比在60、100和270年非常接近,在森林发育后期观测样地的树种组成与预测结果吻合程度良好。对裸地上森林模拟,表明森林的动态过程规律是,蒙古栎和白桦(BetulaplatyphylaSukacz.)在林分发育开始占优势,中期形成阔叶树和针叶树混交,但以阔叶树为主的森林,后期渐被红松取代。对现实原始林预测显示,森林未来300年变化稳定,红松株数和生物量变化很小。  相似文献   

20.
This paper studied edge effects resulting from logging to reforestation on the distribution of ground-dwelling beetles (Coleoptera) across ecotones between natural oak forests and mature pine plantations established after harvesting of natural forests. Using pitfall traps, ground-dwelling beetles were investigated at three replicated plots (ecotones) with three sampling positions of slope (lower, middle and upper) for each plot. Rarefaction estimates of species richness indicated that traps on natural forests and transition zones had more species than mature plantations did, and traps on the middle slope had more species than on the lower and upper slopes did. Results of an ANOVA analysis, which used forest type and slope position as factors and number of species and individuals as the response variables, showed a significant effect of forest type and slope position, and a significant interaction between forest type and slope position. Multivariate analyses (DCA and CCA) showed that beetles of transition zones were more similar to those of natural forests than to those of mature plantations, and that some environmental characteristics, i.e., proportion of broad-leaved trees, canopy cover and elevation (slope position), significantly affected species abundances. We conclude that the logging of natural oak forests and the reforestation of pine plantations can result in subtle variation in the composition and distribution of beetle assemblages at a local scale and such variation should be taken into account when conservation issues are involved.  相似文献   

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