Effects of the overstory on the diversity of the herb and shrub layers of Anatolian black pine forests

Understory plants are important components of forests because they are responsible for the majority of the vascular plant diversity of forest ecosystems. The richness and composition of understory communities are closely related to the tree layer diversity, structure and composition. The aim of this study was to examine the understory diversity of Anatolian black pine (Pinus nigra Arnold subsp. pallasiana (Lamb.) Holmboe)-dominated forests on the Kazda?? Mountains of West Turkey. To describe the overstory structure and composition in a numerically and quantitatively well-defined manner, cumulative abundance profiles (CAPs) of the tree species were used. The resemblance of the sampling plots was classified into five stand types assessing the CAP through the Fuzzy C-Means clustering method. A permutational multivariate analysis of variance (PERMANOVA) was performed to test the variance of the community ecological distance between the five stand types, and the results showed significant differences in these clusters. Many shade-tolerant plants were associated with the mixed stands of Anatolian black pine–Kazda?? fir. The composition of the herb and shrub layer could not be explained by the environmental variables but by differences in the overstory structure of the stands. Pure or nearly pure Anatolian Black pine stands were more diverse than mixed oak–Anatolian black pine and Kazda?? fir–Anatolian black pine stands. However, although dense and young pure Anatolian black pine stands had the most diverse plant species in the shrub layer, they were ranked third in terms of the herb layer diversity. The Anatolian black pine–Kazda?? fir mixed stands had the lowest herb and shrub layer diversity. These results allow us to comprehend the relationship between the overstory structure and composition, and the understory diversity. Understanding this relationship is important for the conservation of understory plant diversity in the management of forest ecosystems.     

Plant diversity and soil properties in pristine and managed stands from Bosnian mixed forests

We compared pristine and managed beech–fir mixed forestsin Bosnia to assess the impact of management on plant speciesdiversity, vegetation structure and soil–vegetation interaction.Traditionally, management of Bosnian mixed forests has beenby the opening of small gaps, similar to those occurring naturally.Species composition revealed three successional vegetation groups,two mainly in managed forests (regenerating and mature) andone mainly in pristine old growth forests. Managed sites showeda tendency to be more diverse in plant species than pristinesites, and were also more heterogeneous. Diversity was clearlyexplained by vegetation groups; mature managed stands showingthe highest plant diversity and regenerating stands the lowest,both in terms of species richness and abundance distributions.Plant diversity decreased with canopy cover and increased withcarbon concentration in the A_h horizon, being accurately modelledby both factors. Although topographical conditions were homogeneousamong sites, vegetation was very sensitive to small changesin environmental variables at the local scale. Vegetation reflecteda combination of past situations, represented by C in the A_hhorizon, and current conditions, represented by canopy coverand the C : N ratio in the LF organic layers, suggesting bothsensitivity to present-day environmental conditions as wellas the imprint of past events.     

Patterns of forest use and endemism in resident bird communities of north-central Michoacán, Mexico

We compared breeding avian communities among 11 habitat types in north-central Michoacán, Mexico, to determine patterns of forest use by endemic and nonendemic resident species. Point counts of birds and vegetation measurements were conducted at 124 sampling localities from May through July, in 1994 and 1995. Six native forest types sampled were pine, pine–oak, oak–pine, oak, fir, and cloud forests; three habitat types were plantations of Eucalyptus, pine, and mixed species; and the remaining two habitats were shrublands and pastures. Pastures had lower bird-species richness and abundance than pine, oak–pine, and mixed-species plantations. Pine forests had greater bird abundance and species richness than oak forests and shrublands. Species richness and abundance of endemics were greatest in fir forests, followed by cloud forests. Bird abundance and richness significantly increased with greater tree-layer complexity, although sites with intermediate tree complexity also supported high abundances. When detrended correspondence-analysis scores were plotted for each site, bird species composition did not differ substantially among the four native oak-and-pine forest types, but cloud and fir forests, Eucalyptus plantations, and mixed-species plantations formed relatively distinct groups. Plantations supported a mixture of species found in native forests, shrublands, and pastures. Pastures and shrublands shared many species in common, varied greatly among sites in bird-species composition, and contained more species specific to these habitats than did forest types.     

Impact of logging on tree,liana and herb assemblages in a Bornean forest

In the present study, the impact of logging was assessed on the forest structure, richness, and composition of trees, lianas, and ground herbs in Indonesian Borneo. There were no significant differences in tree height, diameter, basal area, or abundance between unlogged and logged forest. Liana abundance was higher in logged than unlogged forest, but the difference was marginally nonsignificant. There was also no significant difference in the percentage cover of ground herbs. Tree species richness was similar between unlogged and logged forest, while liana species richness was higher in logged forest and herb species richness between unlogged forest. Tree and liana compositions differed significantly between unlogged and logged forest, but logging explained only a small part (<7%) of the variance in composition. In contrast to trees and lianas, ground herb composition did not differ significantly between unlogged and logged forest. Our findings indicate that the modest extraction intensity practiced did not have a severely adverse impact on forest structure or plant composition. This highlights the important role that logged forests may play in conserving biodiversity and the need to protect these forests from further disturbance.     

Centuries-old logging legacy on spatial and temporal patterns in understory herb communities

Understory herb communities in the Southern Appalachians are among the highest biodiversity plant communities in North America. In the mid-1990s, a debate began over whether understory herb communities recover to their pre-disturbance states following logging. Studies showing reduced herb-layer diversity in previously logged forests were criticized for not accounting for intersite environmental heterogeneity. More recent studies have addressed environmental heterogeneity, but have neglected long-term recovery by using “mature forests” as young as 80 years old as the benchmark for diversity comparison, even though old growth stands have disturbance return intervals exceeding 500 years. Here we address concerns clouding previous studies of high-diversity Appalachian herb communities and investigate their long-term recovery by comparing paired sites of old growth forest and forest logged 100–150 years ago. We found that species richness and individual abundance is greater in old growth forests than mature forests and that species composition differed significantly between the two. Turnover in species among old growth and mature forests accounted for 11% of the total species richness and was significantly greater than expected. Species turnover at intermediate (5–50 m) and landscape-scales (>10 km) contributed the most towards total species richness. Herb communities in rich cove forests have successional trajectories that exceed 150 years, with important community changes still occurring long after the forest returns to what has been previously termed a “mature” state. To conserve the diverse herb layer, we conclude that mature forest stands are too young to serve as baselines for recovery, landscape-scale preservation of multiple forest stands is needed to maximize species richness, and maintaining 100–150-year logging rotations will likely lead to loss of biodiversity.     

不同林龄桉树林下植被多样性分析

以广东省信宜市中部山区不同林龄（3 a 生和 5 a 生）桉树人工林为研究对象,通过样地调查, 统计和分析了桉树林下植被结构特征（种类组成、结构与分布）和物种多样性（Margale 丰富度指数、 Simpson 优势度指数、Shannon-Wiener 指数和 Pielou 均匀度指数）。结果表明：（1）3 a 生桉树林下植被共 记录维管束植物23 科 31 属 33 种,5 a 生桉树林林下植被共记录维管束植物 24 科 32 属 35 种,不同林龄 桉树林下植被结构与分布特征差异较大,乔木幼苗、灌木层和草本层的优势种均明显不同;（2）林龄对 桉树林下植被丰富度影响相对较小,但对优势度和均匀度影响较大;随着林龄的增加,桉树林下灌木层 和草本层植被物种多样性均明显下降,其中灌木层下降幅度大于草本层。总体而言,林龄对林下植被的 种类组成影响相对较小,但对林下植被的结构与分布以及物种多样性有显著影响。     

A preliminary study on the effects of line and selective thinning on bird communities in Hokkaido, northern Japan

In Japan, selective thinning is a common thinning method, though line thinning receives much attention because of its economic merits. In this study, we examined effects of the two thinning methods on bird communities in Todo fir (Abies sachalinensis) plantations in Hokkaido, Japan. We surveyed bird species in forests under four different management types — unthinned, selectively thinned, line-thinned plantation, and naturally regenerated forest (here after referred to as natural forest) stands — using a line-transect method. We also investigated vegetation structure (canopy tree and understory) of these stands. Bird species richness did not differ between natural forests and plantations, while bird total abundance was greater in plantations than in natural forests. Bird species richness and total abundance were comparable among the three management types for plantations. Abundances of 10 bird species were different among the four management types, and five species were more abundant in line-thinned plantations. However, two species were more abundant in selectively thinned stands than in line-thinned stands, and they frequently appeared in natural forests. There were no distinct differences in vegetation structure among the management types for plantations. Our results suggest that line thinning could be beneficial for some bird species in plantations.     

Truffle abundance and mycophagy by northern flying squirrels in eastern Washington forests

Although much is known about truffle abundance and rodent mycophagy in mesic Douglas-fir forests in the Pacific Northwest, few data are available for dry interior montane forests dominated by ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), and grand fir (Abies grandis). Our objective was to quantify the relationship between the abundance and diversity of ectomycorrhizal fungal sporocarps in the soil and in the diets of northern flying squirrels (Glaucomys sabrinus) in low-elevation forests of the eastern Washington Cascades. We randomly sampled four stands each of three cover types: dry open ponderosa pine, mesic young mixed-conifer forest, and mesic mature mixed-conifer forest. We sampled the soil for hypogeous sporocarps during the spring of 1999 and 2000. We collected fecal pellets from 318 flying squirrels live-trapped during the fall of 1997–2000. We sampled 2400 m² of soil surface and found truffles in 40% of 600 plots. Total biomass collected was 609 g. Spring truffle biomass on a kg/ha basis averaged 1.72 in open pine, 3.56 in young, and 4.11 in mature forest. Twenty-two species were collected across all cover types, with all but three species belonging to the Basidiomycotina. Eleven dominant species accounted for 91–94% of truffle biomass in each cover type. Four dominant species accounted for 60–70% of spring truffle biomass: Gautieria monticola, Hysterangium coriaceum, Rhizopogon parksii, and R. vinicolor. Truffle assemblages, richness and total biomass differed among cover types: richness and biomass were highest in young and mature mixed-conifer forest, and lowest in open ponderosa pine forest. Fall squirrel diets were composed of 23 genera or groups of fungi, plus about 22% plant material. Rhizopogon was the most abundant genus in the diet, followed by plant material, then Gautieria, Leucogaster, Alpova, and Hysterangium. Diets in different cover types were similar in the composition, richness, evenness, and the ratio of fungus to plant material. Diet richness varied over the study period. Nineteen truffle genera were detected in fall fecal samples versus 12 in spring soil samples. Management of low-elevation dry forest to maintain or restore stable fire regimes might reduce truffle diversity at stand scales by simplifying stand composition and structure; but, such management might increase long-term beta and landscape truffle diversity and persistence by reducing the occurrence of high-intensity fires and stabilizing inherent fire disturbance regimes.     

The ecology of tree regeneration in mature and old forests: combined knowledge for sustainable forest management

We focused our attention on quantifying the factor complex of forest regeneration in 423 mature and old stands with contrasting environmental conditions. We recorded the microhabitat selection of tree recruits, the frequency of tree seedlings, and evaluated the drivers of sapling abundance and diversity. The majority of forest regeneration was established on undisturbed forest floor. Dead wood was a frequent substrate in spruce-(co)dominated forests. Seedling frequency within a stand was related to the site-type specific productivity gradient of stands—pine seedlings were common in low-productivity and spruce in high-productivity boreal forests. Seedlings of temperate broad-leaved trees dominated in productive boreonemoral forests, except for oak, which showed a uniform distribution of abundance in all forest site-types. Sapling abundance was dictated by forest site-type, and facilitated by stand diversity, variability in stand closure, lying dead wood, abundant moss, and a thick organic layer. Only in boreal forests was sapling abundance suppressed by the abundant spruce and younger trees. Upon considering the relationship between sapling abundance and species richness, sapling diversity was dependent on forest site-type, suppressed by stand density and dead wood (old gap) abundance, and facilitated by stand diversity. In addition, boreonemoral stands, competition from herbs, and facilitation by mosses occurred. The observed pattern of tree recruitment points to the importance of top-down effects of the overstory, competing or facilitating interactions with forest floor vegetation, and availability of regeneration microhabitats, which in complex make their ecology comparable with forest herbs. Natural forest regeneration can be enhanced if silvicultural methods support mixed stands and enhance field layer diversity. Oak can provide the universal tree species to improve stand structure over a wide range of habitats.     

卧龙自然保护区大熊猫栖息地植物群落多样性研究:丰富度、物种多样性指数和均匀度

根据64个植被样方调查资料,分析卧龙自然保护区大熊猫栖息地植物群落多样性特征.结果表明:卧龙自然保护区大熊猫栖息地不同植被类型的物种多样性指数值H'、D和均匀度指数Jsi基本表现出一致的变化趋势:常绿落叶阔叶林＞温性针阔混交林＞落叶阔叶林＞温性针叶林＞亚高山针叶林,而物种丰富度S变化为温性针叶林＞落叶阔叶林＞常绿落叶阔叶林＞亚高山针叶林＞温性针阔混交林.在不同的植物群落中,由于地形地势、坡度、土壤、水热条件等原因,其物种多样性指数不同,但其多样性测度指标除物种丰富度外均呈现出基本一致的变化趋势.随海拔的升高,大熊猫栖息地物种丰富度、多样性指数和均匀度变化先增加,然后下降,最后趋于平稳.坡度不是影响卧龙野生大熊猫栖息地生物多样性的关键因子.不同的坡向其物种丰富度S变化为西＞北＞东＞南,物种多样性指数H'、D呈现西＞南＞北＞东的递降格局,均匀度指数Jsi呈现南＞西＞东＞北的递降格局.在不同的群落中,物种丰富度变化表现为灌木层＞乔木层＞草本层,且42.9%群落中乔木层大于灌木层、64.3%群落中乔木层大于草本层、92.9%群落中灌木层大于草本层,落叶针叶林乔木层树种丰富度小于灌木层和草本层,但其灌木层物种丰富度大于草本层.在同一或不同生长型中,物种多样性指数和均匀度指数变化大体一致.     

Collembola communities and soil conditions in forest plantations established in an intensively managed agricultural area

The challenges of a changing climate have directed greater attention to afforestation,but the effects of afforestation on soil fertility and soil biota have not been fully clarified.To explore changes in the soil conditions in two 20-year-old forest plantations established in formerly intensively fertilized plots of agricultural land,we focused on the current developmental state of the sites that received the most fertilizer and evaluated soil properties and Collembola(springtails) communities.Sessile oak(Quercus petraea) and black locust(Robinia pseudoacacia) that had been planted in the afforestation sites were assessed for differences between plantations of native and invasive species.Five adjacent reference associations,including forests and open habitats,were also analyzed and compared.Results showed that the soils in the two afforested sites were similar in their properties and Collembola communities to those of the control cultivated forests,but differed from each other in pH,calcium,phosphorus,and ammonium content.The available potassium and phosphorus contents in the soil of the sessile oak plantation were still high,while the soil organic matter content was adequate(SOM 2.0%) in both plantations.Species richness of Collembola ranged from 18 in the cultivated arable land to 43 in the relict forest.Only a few species typical for forests(e.g.,Neanura muscorum,Isotomiella minor,Entomobrya muscorum) were detected in the young plantations,while species characteristic of open habitats(e.g.,Protaphorura campata,Lepidocyrtus cyaneus) occurred as well.Although more individuals and species of Collembola were present in the soil of young plantations than in arable fields,their community diversities were significantly lower compared to the control forest stands.Collembola community diversity differed significantly also between the two plantation types(with native and non-native tree species).Mean abundance in the afforested sites was about 2.5 times higher than in the cultivated arable land,yet far lower than the mean abundance in the control forests.     

Response of ground beetles (Coleoptera: Carabidae) to forest gaps formed by a typhoon in a red pine forest at Gwangneung Forest,Republic of Korea

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.     

Tropical reptiles in pine forests: Assemblage responses to plantations and plantation management by burning

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.     

桂西南岩溶区不同恢复模式群落生物量及林下植物多样性

[目的]研究桂西南岩溶区不同恢复模式群落的生物量及其林下植物多样性的特点,为该区域的生物多样性保护、生态功能恢复效果评价积累基础数据。[方法]以桂西南岩溶区4种不同恢复模式为研究对象,采用样方法对林下植物多样性进行研究;采用收获法研究灌木层与草本层的地上、地下生物量及凋落物层现存量;采用异速生长模型来估算乔木层的地上生物量,并参考IPCC根茎比来量化乔木的地下生物量。[结果]表明:共调查记录林下植物85种,隶属于46科,81属,其中,灌木植物25科,46属,50种;草本植物21科,35属,35种;不同恢复模式群落生物量的变化趋势为自然恢复林(166.66 t·hm-2)任豆林(48.61 t·hm-2)吊丝竹林(36.54 t·hm-2)灌草坡(0.96 t·hm-2)。[结论]不同恢复模式灌木层物种丰富度差异不显著,最高的为灌草坡(16种),其次为任豆林(15种),最低为自然恢复林(12种);草本层物种丰富度最高的为任豆林(12种),其次为灌草坡(10种),最低为自然恢复林(4种)。自然恢复林乔木不同组分生物量与任豆林、吊丝竹林之间差异显著(P0.05);灌草坡的灌木、草本地上生物量与吊丝竹林、任豆林、自然恢复林之间差异显著(P0.05)。吊丝竹林、任豆林的灌草生物量表现为草本层灌木层,而灌草坡与自然恢复林的灌草生物量则表现为灌木层草本层。     

Regeneration strategies influence ground bryophyte composition and diversity after forest clearcutting

Context

Natural regeneration with broadleaved species and reforestation with coniferous trees are two widely practiced forest regeneration strategies after timber harvesting. They lead to different tree species composition and may cause different understory biodiversity, but the effects on ground bryophyte composition and diversity are not well-known.

Aims

We tested whether natural regeneration with broadleaved species and reforestation with spruce induced different diversities of the ground bryophyte populations 20–40 years after old-growth spruce forest clearcutting in the subalpine regions of southwestern China.

Methods

Differences between natural stands and plantations were compared through the analysis of 13 paired stands, with 78 plots, 390 shrub/herb quadrats, and a total of 1,560 bryophyte quadrats.

Results

Naturally regenerated forests were characterized by lower density and cover and lower tree height but higher herbaceous plant height, shrub cover, and bryophyte diversity. They also harbored many more ground bryophytes. The species richness of pleurocarpous mosses and fans, mats, and turfs were significantly higher in naturally regenerated forests. Frequency difference analysis demonstrated that more bryophyte species preferred ground habitats in naturally regenerated forests than in plantations (116 vs. 48 species). The canonical correspondence analysis indicated that stand structure attributes were more important determinants of ground bryophyte diversity and abundance.

Conclusion

Natural regeneration and reforestation resulted in large differences in ground bryophyte populations. A larger diversity was observed in the former case, and natural regeneration practices can be an effective measure for the protection of ground bryophyte diversity after clearcutting.     

间伐强度对杉木人工林林下植被和土壤性质的影响

【目的】从发展林下植被、改善群落结构的角度,探讨适合杉木人工林的间伐强度,为提高人工林的稳定性和维护地力、维持人工林的可持续经营提供依据。【方法】2013年对福建省将乐国有林场的杉木人工林采取3种强度间伐:弱度间伐(LT,10%～25%)、中度间伐(MT,25%～35%)和强度间伐(HT,40%～50%),并设置对照样地(CK,未间伐)。于2016年对样地内林木进行每木检尺,调查林下植被物种多样性、盖度、生物量和土壤理化性质。对测定数据进行单因素方差分析,用Tukey法多重比较进行两两差异显著性检验,并对林下植被与土壤理化性质进行Pearson相关分析。【结果】间伐3年后,未间伐、弱度和中度间伐的盖度分别为25.52%、52.81%和58.98%,林下植被均未能形成群落,强度间伐的盖度为100%,林下形成灌木蕨类群落;灌木层物种丰富度、多样性指数、盖度和生物量均随间伐强度增加而增加,均匀度指数随间伐强度的增加而降低;草本层物种丰富度、多样性指数、均匀度指数、盖度和生物量均随间伐强度增加而增加;间伐3年后,弱度、中度、强度间伐林比未间伐林的表层土(0～10 cm)有机质含量分别增加71.41%、39.31%和98.10%,全氮含量分别增加82.76%、51.27%和115.87%,碱解氮含量分别增加49.47%、25.59%和42.22%,有效磷含量分别增加138.29%、112.23%和174.29%,速效钾含量分别增加-16.25%、-24.25%和16.27%,对表层土pH值、全磷含量和土壤物理性质的影响均不显著;灌木的盖度和生物量与土壤的有机质、全氮、全磷和有效磷含量均显著(P<0.05)正相关,此外灌木的盖度还与速效钾含量显著(P<0.05)正相关,草本盖度与土壤理化性质相关性不强,草本生物量与土壤有机质、全氮、全磷、碱解氮以及有效磷含量显著(P<0.05)正相关,林下植被的盖度和生物量均与土壤pH值和物理性质没有显著相关性。【结论】未间伐的杉木人工林林下植被的物种多样性、盖度和生物量均低,林下植被未能形成群落,缺乏稳定性;间伐能够促进林下植被的发育,增加林下植被生物多样性、盖度和生物量,林下植被能形成群落,可提高维护地力的能力,尤其是强度间伐;建议杉木人工幼龄林进行40%～50%强度的抚育间伐,将郁闭度调整到0.6～0.7较为合理。     

Structure and diversity of small-mammal communities of lowland forests in the rural central European landscape

Small-mammal communities were monitored over 4 years in South Moravian rural lowland forests in order to study relationships with various forest habitat types. Early successional sites (plantations) and forest edges maintained communities with higher abundance and diversity. Lowest total abundance was observed in unmanaged lowland forest and highest abundance in plantations with irregular undergrowth management. Low diversity was typical of non-fruiting monocultures. In plantations, both diversity and abundance were affected by herb layer removal, with sites subject to regular cutting, displaying lower levels. Significant differences in diversity and species richness were only detected between early and late successional sites, with the former showing higher values. Two basic small-mammal community groups were determined; (1) those inhabiting sites with a thick herb undergrowth and an open tree canopy (plantation) and (2) those inhabiting stands with sparse or no herb layer and a closed canopy (high forest). Forest stands support long-term populations of dominant small forest-dwelling mammal species and, as such, serve as reservoirs, even in rural landscapes dominated by intensive arable farming. Managed early succession lowland forests represent important refuges for a number of small open-habitat mammals negatively affected by intensive farming.     

Habitat structure influences the spider fauna of short-rotation poplar plantations more than forest age

Plantation forests comprise an important part of the forested areas in European countries. Intensive forestry management and short-rotation cycles of plantation forests reduce habitat diversity and change the composition of invertebrate assemblages, mainly by reducing the number of habitat specialist species. Here, we analysed the effect of vegetation structure, amount of dead organic matter (DOM) and plantation age on spider functional diversity and assemblage structure in short-rotation plantations of native silver poplar in Hungary. Three stages, representing young plantations, 6- to 10-year-old stands (five stands), middle-aged plantations, aged between 23 and 26 years (five stands) and mature, 35- to 37-year-old forests at commercial maturity (five stands) were sampled. Each sample consisted of the data of ten pitfall traps. Traps were installed 5 m from each other in a 2 × 5 grid. Functional diversity was positively related to vegetation structure. High functional diversity indicates a higher number of available niches and potential resources. The abundance of moist habitat species and forest specialist species was positively correlated with DOM. Furthermore, moist habitat species were also related to vegetation structure. The most important environmental parameters affecting spiders were factors attributed to trees (litter and DOM), understory vegetation structure and, to a lesser extent, forest age. Different-aged stands may be similar in terms of species composition of their spider fauna if they comprise the same habitat structural patterns. Our study emphasises that the simple habitat structure of plantation forests has a negative effect on spider communities.     

Breeding bird community composition in different successional vegetation in the montane coniferous forests zone of Taiwan

To examine the relationship between forest succession following fire and the composition of bird communities, we investigated the vegetation structure, bird population density, foraging behavior and guild structure in bamboo grasslands (11 years since the last fire), pine savanna (41 years), pine woodland (58 years), old-growth hemlock forest (never burned), and old-growth spruce forest (never burned) in the Tatachia area of central Taiwan. Canopy height, total foliage cover, tree density, total basal area of tree, total basal area of snags, foliage height diversity, and tree species richness all increased with successional age. However, shrub cover peaked in intermediate successional stages. The vertical profile of foliage cover was more diverse in later successional forests, which had more breeding bird species and ecological guilds. All the breeding bird species recorded in early and intermediate stages were also found distributed in the late successional forests. Because Taiwan has high precipitation and humidity, and most forest fires in Taiwan are caused by human activities, forest fires and large areas of early successional vegetation were probably rare in the mountain areas of Taiwan prior to the arrival of humans. Therefore, bird species have not had enough time to adapt to areas with early or intermediate successional vegetation. Moreover, late successional forests host all the major plant species found in the early and intermediate stages and have higher foliage height diversity index, which was positively correlated with the bird species richness and bird species diversity index in this study. As a result, all breeding bird species and guilds in the area can be found in late successional forests. Efforts for conserving avian diversity in Taiwan should focus on protecting the remaining native old-growth forests.     

Effect of stand age on bird communities in late-successional Macedonian pine forests in Bulgaria

To gain insight into the question of which vegetation characteristics have the most influence on avian assemblages in late-successional forests, the habitat preferences of bird-guilds in old-growth endemic forests of Macedonian pine were studied over 3 years in the Pirin National Park, Bulgaria. Bird–habitat relationships were investigated by comparing vegetation characteristics, and bird species richness, diversity, abundance, and guild structure of birds (determined according to food type, foraging and nesting sites) between mature (60–100 years old) and over-mature (>120 years old) Macedonian pine forest stands. Studied forest age-classes differed mainly by the density, height and diameter of trees, and the amount of dead wood. The first one of these parameters decreased and the latter two parameters increased with the forest succession. The difference in the vegetation structure affected the abundance of bird-guilds and thus, the overall bird abundance and the structure of avian assemblages within Macedonian pine forests. There was no significant difference in bird diversity among studied forest age-classes, but the overall bird abundance increased with forest maturation. Analyzed by study plots, species richness was higher in over-mature forests, but at cluster level, there was no significant difference between mature and over-mature forest age-classes. Half of the studied (insectivorous, hole- and ground-nesters, bark- and canopy-foraging bird species) guilds were more abundant in over-mature forests, while there was no bird-guild exhibiting a preference for mature forest stands. The abundances of bird-guilds were correlated with tree height, diameter at breast height and the amount of dead wood between the studied forest age-classes and this might explain their preferences for over-mature pine forests. Therefore, for future sustainable management of these endemic forests and the conservation of their avifauna, efforts should focus on protecting the remaining native old-growth forest stands and the importance of the structure of Macedonian pine forests on their bird assemblages should be considered in forestry practices.