Woody species diversity influences productivity and soil nutrient availability in tropical plantations

We investigated the relationship between plant diversity and ecological function (production and nutrient cycling) in tropical tree plantations. Old plantations (65–72 years) of four different species, namely Araucaria cunninghamii, Agathis robusta, Toona ciliata and Flindersia brayleyana, as well as natural secondary forest were examined at Wongabel State Forest, in the wet tropics region of Queensland, Australia. Two young plantations (23 years) of Araucaria cunninghamii and Pinus caribaea were also examined. The close proximity of the older plantations and natural forests meant they had similar edaphic and climatic conditions. All plantations had been established as monocultures, but had been colonised by a range of native woody plants from the nearby rainforest. The extent to which this had occurred varied with the identity of the plantation species (from 2 to 17 species in 0.1 ha blocks). In many cases these additional species had grown up and joined the forest canopy. This study is one of the few to find a negative relationship between overstorey plant diversity and productivity. The conversion of natural forest with highly productive, low-diversity gymnosperm-dominated plantations (young and old Araucaria cunninghamii and Pinus caribaea) was found to be associated with lower soil nutrient availability (approximately five times less phosphorus and 2.5 times less nitrogen) and lower soil pH (mean = 6.28) compared to the other, less productive plantations. The dominant effects of two species, Araucaria cunninghamii and Hodgkinsonia frutescens, indicate that ecosystem functions such as production and nutrient availability are not determined solely by the number of species, but are more likely to be determined by the characteristics of the species present. This suggests that monoculture plantations can be used to successfully restore some functions (e.g. nutrient cycling and production), but that the level to which such functions can be restored will depend upon the species chosen and site conditions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Forest fragmentation, synergisms and the impoverishment of neotropical forests

It is well documented that the negative effects of habitat fragmentation are strong enough to promote local as well as regional extinction of canopy and emergent trees in neotropical forests. However, forest fragmentation does not occur alone, but is always associated with other human-induced threats to trees, such as logging, forest burning and hunting of key vertebrate seed dispersers within forest remnants. This association occurs because forest resources are, at least during a certain period, the main income source for local human populations. It is now possible to establish how these threats act in concert causing tree species impoverishment. Based on a predictive model, it is predicted that the most fragmented forest regions have lost or will lose an important part of their tree diversity. New integrated research must urgently test this prediction and investigate how human activities might be regulated in both old and new tropical forest frontiers to avoid species loss. If we fail to do this we will miss the opportunity of proposing sound and efficient guidelines to rescue neotropical forests from species impoverishment.     

Silvicultural intensification for tropical forest conservation

Minimizing the deleterious environmental impacts of logging and other silvicultural treatments is the primary conservation goal in tropical forests managed for timber production. While it is always environmentally beneficial to minimize unnecessary damage, more intensive silviculture should not be discouraged in tropical forests in which regeneration and growth of commercially valuable timber species requires such treatments. Failing to regenerate commercial species may render forests more susceptible to conversion to other, more lucrative land uses. Increasing the intensity of silviculture may also decrease the total area of forest exploited for timber, thereby reducing the impacts of over-hunting, timber theft, wildfires, colonization, and conversion, which are facilitated by the increased accessibility of logged areas.     

Diversity Patterns of Bornean Butterfly Assemblages

Borneo contains a diverse rainforest butterfly community, but its forests are under threat from logging and ENSO- (El Niño Southern Oscillation) induced fires. Contrasts in butterfly assemblage structure were examined in nine 450 ha landscapes in logged forest, primary unburned continuous and isolated forest, and forest affected by surface fires during the 1997/98 ENSO event. Temporally the effect of the 1997/98 ENSO event was followed in a single burned landscape from 1997 to 2004. In total, 517 species were present in 190 sampling sites. There was a five-fold difference in species richness among landscapes, with highest richness in continuous landscapes and lowest richness in burned landscapes. Richness was also higher in logged forest than proximate unlogged forest. Temporally, species richness dropped dramatically from 1997 to 1998, but afterwards increased remaining, however, substantially lower than pre-ENSO (1997) sampling. Sites in burned landscapes were distinct from other sites in terms of vegetation structure with the slash-and-burn area the most dissimilar to other landscapes. There was much less structure among unburned landscapes. The pattern of butterfly community composition was similar to that of vegetation structure with the community from the slash-and-burn area the most distinct. However, there was much less overlap among sites from different landscapes. Temporally, 1998 possessed the most distinct assemblage when compared to assemblages from other years. The community composition was, however, slowly returning to a pre-disturbance composition. Variance in community composition explained by environmental and spatial factors differed substantially among landscapes. The spatial fraction was the only explanatory component in recently burned landscapes and a proximate small unburned isolate, but explained no variation in logged landscapes. The environmental fraction explained substantial amounts of variation in logged landscapes and the slash-and-burn area. When all landscapes were pooled high proportions of variation in butterfly community composition were explained by both geographic distance between sites and environmental variables. In contrast when only unburned landscapes were considered, most variation was explained by the geographic distance among them. Despite differences among landscapes there was a general pattern of relatively sharp decline in similarity at short distances that levels out over greater distances, a result that agrees with previous studies on other tropical species assemblages.     

Plant species diversity in abandoned coppice forests in a temperate deciduous forest area of central Japan

We investigated plant species diversity as it related to stand structure and landscape parameters in abandoned coppice forests in a temperate, deciduous forest area of central Japan, where Fagus crenata was originally dominant. The species occurring in the study plots were classified into habitat types based on a statistical analysis of their occurrence bias in particular habitats (e.g., primary forest, coniferous plantation) in the landscape studied. The relationships between stand structure, which reflected the gradient of management, and forest floor plant species diversity (H and J) and richness (number of species per unit area) were not significant. However, these factors did influence the forest floor plant composition of the different types of habitat. According to the multiple regression analysis, species diversity and the richness of forest floor plants was affected by landscape parameters rather than by stand structure. For trees, species richness was mainly affected by the relative dominance of F. crenata, which is one of the stand structure parameters that decreases with intensive management. This is probably because many of the tree species that are characteristic of coppice forests increase after F. crenata have been eliminated by management; these species are not dominant in the original forest, where they are suppressed by F. crenata, the shade-tolerant dominant species. The species diversity (H and J) of trees was positively correlated with some landscape parameters, including the road density around the study plot, which may be associated with the intensity of management activity. The number of disturbance-tolerant species increased with increasing road density. Stand structure mainly affected disturbance-intolerant forest floor plant species and disturbance-tolerant tree species. Thus, the species diversity responses differed between forest floor plants and trees. The impact of forest management on species diversity was more prominent for forest floor plants.     

Sapling growth as a function of light and landscape-level variation in soil water and foliar nitrogen in northern Michigan

Interspecific differences in sapling growth responses to soil resources could influence species distributions across soil resource gradients. I calibrated models of radial growth as a function of light intensity and landscape-level variation in soil water and foliar N for saplings of four canopy tree species, which differ in adult distributions across soil resource gradients. Model formulations, characterizing different resource effects and modes of influencing growth, were compared based on relative empirical support using Akaike’s Information Criterion. Contrary to expectation, the radial growth of species associated with lower fertility (Acer rubrum and Quercus rubra) was more sensitive to variation in soil resources than the high fertility species Acer saccharum. Moreover, there was no species tradeoff between growth under high foliar N versus growth under low foliar N, which would be expected if growth responses to foliar N mediated distributions. In general, there was functional consistency among species in growth responses to light, foliar N, and soil water availability, respectively. Foliar N influenced primarily high-light growth in F. grandifolia, A. rubrum, and Q. rubra (but was not significant for A. saccharum). In A. saccharum and A. rubrum, for which soil water availability was a significant predictor, soil water and light availability simultaneously limited growth (i.e., either higher light or water increased growth). Simple resource-based models explained 0.74–0.90 of growth variance, indicating a high degree of determinism. Results suggest that nitrogen effects on forest dynamics would be strongest in high-light early successional communities but that water availability influences growth in both early successional and understory environments.     

A comparative measure of biodiversity based on species composition

In conservation planning, species richness and species endemism are the most often used metrics for describing the biodiversity importance of areas. However, when it comes to prioritizing regions for conservation actions these measures alone are insufficient because they do not reveal how similar or different the actual composition of species may be from one area to another. For comparative analysis an additional useful metric would be one that indicates the degree to which the species assemblage in one area is also represented in—or is distinct from—species assemblages of other areas. Here we describe a method for quantifying the compositional representativeness of species assemblages among geographic regions. The method generates asymmetric pairwise similarity coefficients that are then used to calculate separate measures for the representativeness and the distinctiveness of species assemblages in the regions being compared. We demonstrate the method by comparing fish communities among freshwater ecoregions of the Mississippi Basin, and then among smaller hydrological units within two individual freshwater ecoregions. At both scales of analysis, our measures of representativeness and distinctiveness reveal patterns of fish species composition that differ from patterns of species richness. This information can enhance conservation planning processes by ensuring that priority-setting explicitly consider the most representative and distinctive species assemblages.     

Response of bird assemblages to windstorm and salvage logging — Insights from analyses of functional guild and indicator species

Natural disturbances, such as fire, windstorms and insect outbreaks, are important drivers of biodiversity in forest ecosystems, but at the same time cause large economic losses. Among the natural disturbances in Europe, windstorms cause the highest economic loss. After such storms, damaged forest stands are commonly salvage logged to restore economic value. However, such interventions could affect species assemblages of various taxonomic groups, including breeding birds. Despite these potential effects, investigations of the impacts of post-storm logging are largely lacking. We thus investigated assemblages of breeding birds in 21 logged and 21 unlogged windstorm-disturbed forest plots and 18 undisturbed, control forest plots using fixed-radius point-stop counts three, five and seven years after a windstorm within the Bavarian Forest National Park as part of the European Long-Term Ecosystem Research Network. We recorded 2100 bird individuals of 55 bird species. Bird assemblages were predominantly altered by the consequences of the windstorm and affected only to a minor degree by subsequent logging of storm-felled trees. Nevertheless, bird species richness was significantly reduced by post-storm logging within the first season. In general, the windstorm led to a shift in bird assemblage composition from typical forest species towards open- and shrub-land species. Assemblages of logged and unlogged disturbed plots consisted mainly of long-distance migrants and ground-foraging bird species, whereas assemblages of undisturbed control plots consisted of resident species that forage within vegetation. Both unlogged and logged storm-felled coniferous forest stands were inhabited by endangered or declining bird species, such as Water Pipit (Anthus spinoletta) on logged plots and Eurasian Redstart (Phoenicurus phoenicurus) on unlogged plots. Indicator species analyses suggested that species of unlogged storm disturbed plots depended on storm-created legacies, such as pits and snags, for foraging and nesting. Hence, we recommend reducing post-storm logging of these legacies to support species restricted to unlogged disturbed forest. To increase the diversity of breeding birds on the landscape scale, diverse logged and unlogged post-disturbance stands should be provided, which could be gained by a partial benign neglect strategy of storm disturbed forest stands.     

Tree community features of two stands of riverine forest under different flooding regimes in Southern Brazil

Two 1 ha plots of a Southern Brazilian subtropical riverine forest, subject to different frequency and duration of floods, were compared to detect the differences in physiognomic structure, tree community composition, richness and diversity. Each plot was made up of 100 contiguous 10×10 m subplots, where 3451 trees with pbh 15 cm were measured and identified. The survey observed 30 tree species, in the frequently flooded plot and 48 in the occasionally flooded plot. A detailed topographical and soil survey was carried out in both plots and indicated that the levels of organic matter and most mineral nutrients were higher in the frequently flooded stand. The forest understory was denser in the occasionally flooded stand which also showed taller emergent trees. Multivariate ordination and grouping techniques showed that the species’ abundance distribution was strongly related to the topographical variation. There was a clear pattern of species turnover according to topographic position, indicating that tree species developed different abilities to survive flooding events. As a result, the two plots also differed in their tree frequency per species regeneration, vertical distribution and dispersion groups. Both species richness and diversity decreased with increasing flood frequency, also showing a patchy distribution within both stands. At a local scale, flooding regime is regulating the spatial variation of α-diversity by forming different seral stages of predictable species composition. Compared to regularly flooded riverine and floodplain forests, riverine forests, with unpredictable flooding regimes, may show higher diversity at a local scale and more abundant opportunistic species of high environmental plasticity.     

贵州省哺乳动物名录更新

在《贵州兽类志》的基础上,参照最新的哺乳动物分类学和分子系统学研究成果,梳理2019年12月31日以前与贵州省哺乳动物相关的研究资料,变更了一些贵州省原记录的哺乳动物物种名称和分类地位,更新了贵州省哺乳动物名录。更新后的贵州省哺乳动物名录共记录哺乳纲9目29科84属153种。其中,翼手目56种、啮齿目38种、食肉目24种、劳亚食虫目19种、偶蹄目7种、灵长目4种、兔形目3种、鳞甲目和攀鼩目各1种。与《贵州兽类志》相比,共计新增哺乳动物36种,包括近年来在贵州发现的5个新种,水甫管鼻蝠(Murinashuipuensis)、梵净山管鼻蝠(M.fanjingshanensis)、榕江管鼻蝠(M.rongjiangensis)、荔波管鼻蝠(M.liboensis)和黑姬鼠(Apodemus nigrus);1个中国新记录种,即2011年发表的艾氏管鼻蝠(M.eleryi);14个贵州分布新记录种,以及近年来有研究证据支持分布于贵州的17个种;此外,由于标本鉴定有误,或同物异名,或被研究证实不分布于贵州等原因,删除了23个物种。贵州省境内目前记录到的重点保护野生动物有19种,其中,国家Ⅰ和Ⅱ级...     

舟山岛自然栖息地的变化及其对兽类物种绝灭影响的初步研究

舟山岛自然栖息地和物种受到人类活动的强烈干扰．占总面积５６．３％的自然栖息地已经消失,自然栖息地已破碎成许多碎片,碎片面积不断变小,碎片数量在增加．自然栖息地的质量发生了很大变化．自然栖息地的易破碎带与其地理特征有关,破碎易发生于被开垦和开发的地带．由于自然栖息地面积损失、破碎、质量下降和过度捕杀,已有５种兽绝灭,３种兽正走向绝灭,绝灭速度高于临近大陆．人口增长是舟山岛自然栖息地损失、破碎、质量下降和物种绝灭的根本原因．本文还讨论了保护自然栖息地和物种多样性的一些措施和原则．     

Effects of topography on tropical lower montane forests under different geological conditions on Mount Kinabalu,Borneo

Species composition and forest structure change with topography.However, mechanisms for topographical vegetation changes are still not wellunderstood, because a topographical gradient is a complex environmentalgradientinclusive of many factors. The foot of Mt. Kinabalu is covered with three typesof geological substrates, i.e. Quaternary and Tertiary sedimentary rocks andultrabasic (serpentine) rock. Quaternary and Tertiary sedimentaryrocks are different in site age, but controlled in primary minerals. Tertiarysedimentary and ultrabasic rocks are contrasting in primary minerals, but arecomparable in age. This setting provides an opportunity to examine thevegetation differentiation along topographical gradients that are contrastinginmajor-nutrient supply due to the difference in site age and parent rock.We established a total of nine study plots by choosing three topographicalunits(ridge, middle- and lower-slope) on each substrate inthe tropical lower montane forest. Pool size and supply of soil N and Pdecreased upslope on each substrate, and the magnitude of the reduction fromslope to ridge decreased in the order of Quaternary sedimentary > Tertiarysedimentary > ultrabasic rock. Between-substrate difference in soilnutrient condition was greater on the lower-slopes than the ridges.Maximum tree size decreased and stem density increased upslope on eachsubstrate. Detrended correspondence analysis demonstrated that speciescomposition also changed along topographical gradients on all substrates.However, the magnitude of topographical changes in forest structure and speciescomposition varied with substrate and decreased from Quaternary sedimentary>Tertiary sedimentary > ultrabasic rock. The greatest between-substratedifference in vegetation occurred on the lower-slopes. Accordingly, ourresults suggest that the magnitude of vegetation changes due to topographybecomes smaller with decreasing pool size and supply of nutrients.     

Identifying practical indicators of biodiversity for stand-level management of plantation forests

Identification of valid indicators of biodiversity is a critical need for sustainable forest management. We developed compositional, structural and functional indicators of biodiversity for five taxonomic groups—bryophytes, vascular plants, spiders, hoverflies and birds—using data from 44 Sitka spruce (Picea sitchensis) and ash (Fraxinus excelsior) plantation forests in Ireland. The best structural biodiversity indicator was stand stage, defined using a multivariate classification of forest structure variables. However, biodiversity trends over the forest cycle and between tree species differ among the taxonomic groups studied. Canopy cover was the main structural indicator and affected other structural variables such as cover of lower vegetation layers. Other structural indicators included deadwood and distances to forest edge and to broadleaved woodland. Functional indicators included stand age, site environmental characteristics and management practices. Compositional indicators were limited to more easily identifiable plant and bird species. Our results suggest that the biodiversity of any one of the species groups we surveyed cannot act as a surrogate for all of the other species groups. However, certain subgroups, such as forest bryophytes and saproxylic hoverflies, may be able to act as surrogates for each other. The indicators we have identified should be used together to identify stands of potentially high biodiversity or to evaluate the biodiversity effects of silvicultural management practices. They are readily assessed by non-specialists, ecologically meaningful and applicable over a broad area with similar climate conditions and silvicultural systems. The approach we have used to develop biodiversity indicators, including stand structural types, is widely relevant and can enhance sustainable forest management of plantations.     

Lack of adequate taxonomic knowledge may hinder endemic mammal conservation in the Brazilian Atlantic Forest

The Atlantic Forest is one of the most diverse and threatened ecosystems of the world, being thus classified as one of the most important biodiversity hotspots. However, habitat loss, overexploitation, alien species, disease and pollution are not the only threats faced by native fauna and flora. The lack of adequate taxonomic knowledge hinders conservation and management efforts of endemic species. This is true even for mammals, which is the most charismatic group of animals and traditionally receive a good deal of attention from scientists and the public in general. A few examples show how this gap in local fauna information can be demise for species conservation, even misguiding management strategies: molecular data reveal a hidden marsupial diversity; the lack of taxonomic studies at the species level seriously threatens rodent conservation; and the taxonomic rearrangement of the genusBrachyteles revealed a new species and had a great impact on management strategies. New species are discovered, described and taxonomically rearranged at an astounding rate. We can only be successful in biodiversity conservation if we have at least a minimum level of knowledge about what we are trying to preserve. That is true both for researchers and for the general public. Recent taxonomic revisions may represent the turning point in Neotropical fauna knowledge, which, coupled with a greater awareness of local people about the rich biodiversity that dot their backyards, can represent a better conservation prospect for the endemics of the Atlantic Forest.