Foraging by forest ants under experimental climatic warming: a test at two sites

Climatic warming is altering the behavior of individuals and the composition of communities. However, recent studies have shown that the impact of warming on ectotherms varies geographically: species at warmer sites where environmental temperatures are closer to their upper critical thermal limits are more likely to be negatively impacted by warming than are species inhabiting relatively cooler sites. We used a large‐scale experimental temperature manipulation to warm intact forest ant assemblages in the field and examine the impacts of chronic warming on foraging at a southern (North Carolina) and northern (Massachusetts) site in eastern North America. We examined the influence of temperature on the abundance and recruitment of foragers as well as the number of different species observed foraging. Finally, we examined the relationship between the mean temperature at which a species was found foraging and the critical thermal maximum temperature of that species, relating functional traits to behavior. We found that forager abundance and richness were related to the experimental increase in temperature at the southern site, but not the northern site. Additionally, individual species responded differently to temperature: some species foraged more under warmer conditions, whereas others foraged less. Importantly, these species‐specific responses were related to functional traits of species (at least at the Duke Forest site). Species with higher critical thermal maxima had greater forager densities at higher temperatures than did species with lower critical thermal maxima. Our results indicate that while climatic warming may alter patterns of foraging activity in predictable ways, these shifts vary among species and between sites. More southerly sites and species with lower critical thermal maxima are likely to be at greater risk to ongoing climatic warming.     

Bloodsucking dipterans (Diptera: Ceratopogonidae,Culicidae, Simuliidae,Tabanidae) of the Kurgala Peninsula,Leningrad Province

The fauna of bloodsucking dipterans of the Kurgala Peninsula comprises 73 species, 34 of which belong to mosquitoes (Culicidae), 18 to blackflies (Simuliidae), 5 to biting midges (Ceratopogonidae, genus Culicoides), and 16 species to horseflies (Tabanidae). Nine species of the bloodsucking dipterans found on the Kurgala Peninsula are new to Leningrad Province, 6 of them being also recorded for the first time for the neighboring territories of Estonia and southern Finland.     

Climatic preferences and frequent co-occurrence of boreal and temperate plants in Hokkaido Island,northern Japan

Effects of climatic factors on the forest plant distribution were examined in Hokkaido Island, northern Japan, where boreal and temperate plants frequently co-occur, and the relationship of floral make-up with phytogeography and life form was analysed. From the climatic preference of tree species consisting of mixed forest, the co-occurrence of boreal and temperate plants was found over a wider thermal range in regions of little rainfall. However, co-occurrence in a certain forest site was more notable in the understory than in the crown. A particular case of this involves southern evergreen shrubs and herbs in a boreal coniferous forest. Another is the presence of northern summergreen herbs in a temperate hardwood forest. It is speculated that the co-occurrence dates back at least to the late Quaternary, when a decrease in temperature associated with the glacial period forced understory plants to adapt their life form or leaf habit to snowcover and the light conditions of interior forests. Recent geographical evidence suggests that the island has been isolated from the southern island for at least 70000 years. Thus, the postglacial re-expansion of southern species does not appear to be due to immigration but rather due to their expansion from refuges on the island such as Oshima Peninsula for snow-tolerant species and Hidaka District for snow-intolerant species.     

河北北部和内蒙古东部森林-草原交错带森林景观格局初步研究

河北北部、内蒙古东部森林 草原交错带的森林景观主要有白桦林、山杨林、云杉林、蒙古栎林和榆树疏林。森林斑块的数量在森林 草原交错带的森林草甸区最多 ,其次是森林带 ,再次是森林 草原交错带的草甸草原区 ,草原带没有森林斑块。从森林带到森林 草原交错带 ,森林斑块变小、森林景观破碎化程度提高。森林 草原交错带森林景观的形成是气候变化和现代气候、地形、火灾和人为活动综合作用的结果     

Climate-induced changes in the small mammal communities of the Northern Great Lakes Region

We use museum and other collection records to document large and extraordinarily rapid changes in the ranges and relative abundance of nine species of mammals in the northern Great Lakes region (white-footed mice, woodland deer mice, southern red-backed voles, woodland jumping mice, eastern chipmunks, least chipmunks, southern flying squirrels, northern flying squirrels, common opossums). These species reach either the southern or the northern limit of their distributions in this region. Changes consistently reflect increases in species of primarily southern distribution (white-footed mice, eastern chipmunks, southern flying squirrels, common opossums) and declines by northern species (woodland deer mice, southern red-backed voles, woodland jumping mice, least chipmunks, northern flying squirrels). White-footed mice and southern flying squirrels have extended their ranges over 225 km since 1980, and at particularly well-studied sites in Michigan's Upper Peninsula, small mammal assemblages have shifted from numerical domination by northern species to domination by southern species. Repeated resampling at some sites suggests that southern species are replacing northern ones rather than simply being added to the fauna. Observed changes are consistent with predictions from climatic warming but not with predictions based on recovery from logging or changes in human populations. Because of the abundance of these focal species (the eight rodent species make up 96.5% of capture records of all forest-dwelling rodents in the region and 70% of capture records of all forest-dwelling small mammals) and the dominating ecological roles they play, these changes substantially affect the composition and structure of forest communities. They also provide an unusually clear example of change that is likely to be the result of climatic warming in communities that are experienced by large numbers of people.     

Species composition and landscape-zonal distribution of horseflies (Diptera,Tabanidae) in the territory of Belgorod Province

A list of 30 species of the family Tabanidae recorded in Belgorod Province is provided, and data on the landscape-zonal distribution, typical biotopes, and dates of flight in the region are given for each species. The greatest number of horsefly species (24) was recorded in the southern forest-steppe subzone, and smaller numbers, in the central forest-steppe subzone (18) and the steppe zone (16). Half of the forest and forest-steppe species extend into the steppe zone while some southern species penetrate into the forest-steppe zone. The pattern of horsefly distribution is determined by the biotopic conditions. The boundaries of distribution of individual species do not distinctly correspond to those of the landscape subzones.     

Patterns of zonal changes in the spatial structure of Orthopteran communities in the European steppe

Patterns of zonal changes in the species composition, diversity, and community structure of Orthoptera were studied along the latitudinal series of steppe types from meadow to desert steppe in European Russia. The maximum abundance of Orthoptera was recorded in the typical steppe, while the maximum species richness shifted to the southern dry steppe. Changes in the ecological preferences of orthopterans due to aridization are shown by the example of zonal communities. A gradual decline of the forest-steppe orthopteran complex and an increase in the number of semidesert and desert species are demonstrated. The changes in the species composition are accompanied by the intra-landscape shifts of areas with high species diversity. Most species in the meadow steppe occupy mesophytic habitats in depressions. In the typical and dry steppe, the species richness and abundance are restricted to habitats with zonal and xerophytic vegetation. In the desert steppe, the species diversity is the highest in dry habitats, including halophytic ones, where xerophilic and desert species predominate. The diversity and evenness indices increase in the northern and southern ecotones of the steppe zone.     

Cartographic representation of the distribution of black grouse (<Emphasis Type="Italic">Lyrurus tetrix</Emphasis> L.) and hazel grouse (<Emphasis Type="Italic">Tetrastes bonasia</Emphasis> L.) in the West Siberian plain

Distribution of black grouse and hazel grouse was evaluated on the basis of the results of bird counts from July 16 to August 31, 1959–2005 over all natural geographical zones and subzones of West Siberia (with fractioning down to the type of landscape tract). Data averaging over groups of vegetation map units (dynamic series) and other specific averaging procedures revealed that black grouse is common in northern-, middle-, and southern-taiga bogs; in subtaiga pine forests; in grassy bogs combined with halophytic meadows within the boundaries of subtaiga forests and the northern forest-steppe; and in agricultural lands in the northern forest-steppe. Hazel grouse is numerous in southern-taiga and dark coniferous middle-taiga forests and their derivatives. The number of hazel grouse individuals in these habitats is larger than in other lands. In general, over the subzones, both black grouse and hazel grouse are most numerous in the middle and southern taiga and in subtaiga forests. To the north and to the south of these subzones, the abundance of these species decreases. They were not encountered in tundras and some open forest-steppe and steppe habitats.     

Zonal types of host-parasite complexes of arthropods and small mammals in a flat part of Western Siberia

Within a flat part of Western Siberia distribution of the small mammals and parasitic arthropods connected with them is accompanied by formation zonal host-parasite complexes dated for corresponding landscape zones or subzones: tundra complex dated for a tundra zone; forest complex dated for a forest zone (including subzones northern taiga, middle taiga, southern taiga and subtaiga); forest-steppe complex dated for a northern forest-steppe subzone; steppe complex dated for a southern forest-steppe subzone and steppe. Parasitic specificity of each type of a complex is defined by arthropods of different systematical and ecological groups: a tundra complex is defined by epizoite gamasid mites (Mesostigmata), forest and forest-steppe complexes is defined by tick (Ixodides) and fleas (Siphonaptera), steppe complex is defined by fleas and nidicolous gamasid mites.     

Ecological description of ground beetle communities (Coleoptera, Carabidae) in northern taiga meadows of Arkhangelsk Region

Species composition and ecological structure of ground beetle population was studied in northern taiga meadows of the Arkhangelsk Region. Meadows in the northern forest zone proved to harbor 91 ground beetle species. Carabid complexes formed in the intrazonal biocenoses of the northern forest zone can be as rich as the family topical groups in the southern forest zone by the number of species and ecological diversity. Ecological properties of the fauna and ground beetle population proved similar in different parts of the forest zone. The proportion of stenobiotic meadow species proved to decrease while that of ecologically plastic ones increased from south to north. The proportion of the genus Harpalus decreased in the ground beetle population while the number of Amara species remained unaltered and their abundance increased. The changes in the species composition caused no transformation of the ecological structure of ground beetle population since they were limited to a single life form or guild.     

Protected areas act as a buffer against detrimental effects of climate change—Evidence from large‐scale,long‐term abundance data

Climate change is driving species to shift their distributions toward high altitudes and latitudes, while habitat loss and fragmentation may hamper species ability to follow their climatic envelope. These two drivers of change may act in synergy, with particularly disastrous impacts on biodiversity. Protected areas, PAs, may thus represent crucial buffers against the compounded effects of climate change and habitat loss. However, large‐scale studies assessing the performance of PAs as such buffers remain scarce and are largely based on species occurrence data. Conversely, abundance data have proven to be more reliable for addressing changes in wildlife populations under climate change. We evaluated changes in bird abundance from the 1970s–80s to the 2000s inside and outside PAs at the trailing range edge of 30 northern bird species and at the leading range edge of 70 southern species. Abundances of retracting northern species were higher and declined less inside PAs at their trailing range edge. The positive effect of PAs on bird abundances was particularly marked in northern species that rely strongly on PAs, that is, their density distribution is largely confined within PAs. These species were nearly absent outside PAs in the 2000s. The abundances of southern species were in general lower inside PAs and increased less from the 70s–80s to 2000s. Nonetheless, species with high reliance on PAs had much higher abundances inside than outside PAs in the 2000s. These results show that PAs are essential in mitigating the retraction of northern species, but also facilitate northward expansions of southern species highly reliant on PAs. Our study provides empirical evidence documenting the role of PAs in facilitating species to adjust to rapidly changing climatic conditions, thereby contributing to the mitigation of impending biodiversity loss. PAs may thus allow time for initiating wider conservation programs on currently unprotected land.     

Landscape and zonal distribution of bloodsucking mosquitoes and horseflies (Diptera: Culicidae,Tabanidae) in the northeastern Russian Plain

Analysis of landscape and zonal changes in the species diversity and abundance of 34 species of bloodsucking mosquitoes and 42 species of horseflies in the northeastern Russian Plain was carried out. The species diversity of both families is reduced from south to north. Two steps of faunistic depletion can be revealed: at the boundary of the middle and northern taiga (both mosquitoes and horseflies) and at the boundary of the extreme northern taiga and the forest-tundra (horseflies only). Species whose northern and southern distribution boundaries lie within the territory studied are listed.     

Linking tree growth and intra-annual density fluctuations to climate in suppressed and dominant Pinus sylvestris L. trees in the forest-steppe of Southern Siberia

Climate change affects forest dynamics with potential consequences for essential ecosystem services. The retrospective analysis of secondary growth unveils the effect of climate on forests. However, most tree-ring studies focus on dominant trees, and less is known about the climatic response of their neighbor suppressed trees. We evaluated the influence of tree social status (dominant/suppressed) on climate response in Pinus sylvestris L. trees from two sites with contrasting water availability conditions in the forest-steppe ecotone in southern Siberia. Tree-ring width and intra-annual density fluctuations (IADFs) were used as proxies. Late spring to early summer conditions were the main climate drivers in both tree social status, but the climate response of suppressed trees was stronger and had a longer time window (May-June). IADFs’ occurrence was controlled by temperature and its frequency was modulated by local conditions, being more common at the dry site, with tree status just marginally significant. Our results suggest that under the projected warmer and drier climate, suppressed trees in southern Siberia will be prone to increased water shortage, leading to possible higher mortality of more sensitive suppressed trees, with potential consequences for carbon sequestration in the forest-steppe ecosystems in southern Siberia.     

Zonal types of host-parasite complexes of arthropods and small mammals in the west Siberian Plain

Comparative analysis of the composition, population structure, and landscape distribution of small mammals and associated parasitic arthropods was performed for the plain part of West Siberia. Four main zonal complexes were distinguished, corresponding to different landscape zones or subzones: tundra, forest, forest-steppe (the northern forest-steppe subzone), and steppe (the southern forest-steppe subzone and steppes). The parasite specificity of each complex is defined by different systematic and ecological groups of arthropods: the tundra complex is defined by epizoic gamasid mites (Acari: Parasitiformes: Mesostigmata), the forest and forest-steppe complexes are defined by ticks (Acari: Parasitiformes: Ixodides) and fleas (Insecta: Siphonaptera), and the steppe complex is defined by fleas and nidicolous gamasid mites.     

Biotopic distribution and conditions for development of bloodsucking mosquitoes from the subfamily culicinae in Daghestan

The distribution of 21 species of bloodsucking mosquitoes was studied in Daghestan. The relationships between the distribution and number of mosquitoes and the environmental conditions were determined. The hydrological regime, specific features of overgrowing and warming of water bodies affect the distribution of mosquito larvae.     

Soil-moisture conditions indicated by field-layer plants help identify vulnerable forests in the forest-steppe of semi-arid Southern Siberia

High variability in soil-moisture conditions is typical for semi-arid forest-steppe ecosystems where precipitation varies greatly over time. Plant species that inhabit these environments integrate responses to broadly fluctuating wetness conditions. Indirect assessment of contrasting habitat wetness based on plant indicator values, species frequency, and species coverage was carried out in two sites representing the larch (Larix sibirica) and pine (Pinus sylvestris) forest-steppe communities. For the larch forest-steppe, we found that plant community composition and spatial structure depended strongly on wetness. In addition, we found that the vegetation was clearly differentiated into forest stands and steppe communities, depending on the slope aspect. There was also a strong correlation between dissimilarities of species composition and differences in habitat wetness revealed in the larch forest-steppe. In contrast, soil properties, such as gravel and stone content were found to be a key factor in the spatial distribution of plant species composition in the pine-forest-steppe communities. Indirect assessment of moisture conditions in the forest-steppe habitats, based on the field-layer plant species, was found to be preferable for indicating soil water deficits in the forest. Furthermore, as long-term observational data is often lacking, indirect assessment of the forest-steppe vegetation provides an opportunity to identify vulnerable forests at the marginal distribution. Based on indirect assessments of soil-moisture conditions, and taking into account differences in potential drought resistance between larch and pine forests, we concluded that increasing aridity will cause the replacement of Siberian larch by Scots pine in the South Siberian forest-steppe landscape. Consequently, in the future it is likely that forest-steppe typological diversity will decrease, and the semi-arid landscape may become more monotonous.     

中国南部亚热带森林地表植被动态变化

系统研究了南方5个亚热带森林生态系统地表植被的动态变化情况.研究方法是:在每个研究区域内,按照地形梯度分别布设50个1m2 的样方,记录样方内所有物种的频度及相关的环境变量,5个研究区域共设250个样方,每个样方分别调查两次.通过单元及多元统计方法分析表明:维管植物物种频度在一个区域明显下降,另二个区域显著增加;苔藓物种频度在一个区域有明显下降,另一个区域明显增加;苔藓物种数量在3个区域显著增加,另二个区域显著下降;维管植物物种数量显著增加在二个区域;物种组成沿着第一个植被梯度轴DCA 1没有显著变化,沿着第二个植被梯度轴DCA 2在二个区域有显著变化.综合分析表明,苔藓对气候变化及其波动反映敏感,是较好的气候变化及气候波动生物指示因子,而管植物数量及频度的变化没有明显证据显示与土壤酸化和大气污染有紧密关系.     

Effects of forest fragmentation on European birds: implications of regional differences in species richness

Aim In this paper, we adopted a large‐scale approach to evaluate the effect of regional richness of forest birds on the number of bird species retained by forest fragments in several localities across Europe. Location We studied bird assemblages in fourteen forest archipelagos embedded in agricultural matrices from southern Norway to central Spain. Tree composition varied from oak and beech forests of the northern localities to oak and pine xerophitic woodlands of the southern ones. The number of fragments in each forest archipelago ranged from eighteen to 211. Methods We used the Gleason equation (s = a + z log A; where s and A are, respectively, the species richness and size of forest fragments and z the rate of species loss) to estimate the species richness for 1‐ and 15‐ha fragments in each archipelago. The regional richness of forest birds was estimated by modelling the geographical distribution of species richness in the European atlas of breeding birds. Results The latitudinal distribution of regional richness displayed a convex form, with the highest values being in central Europe. Along this gradient, the number of species retained by fragments and the rate of species loss was positively related to regional richness. In addition, the percentage of the regional pool of species sampled by fragments decreased in the southern localities. Main conclusions Relationships between regional richness of forest birds and richness in fragments seem to explain why fragments in central Europe shelter more species than their southern counterparts. The decreased ability of southern forest fragments to sample the regional richness of forest birds, could be explained as an effect of the low abundance of many species in the Mediterranean, which could depress their ability to prevent extinction in fragments by a rescue effect. Alternatively, high beta diversity in the Mediterranean could produce undersampling by fragments of the regional pool of species. These regional differences in the response of bird assemblages to forest fragmentation are used to discuss the usefulness of large‐scale, biogeographical approaches in the design of conservation guidelines.     

High solar radiation hinders tree regeneration above the alpine treeline in northern Ecuador

Many tropical alpine treelines lie below their climatic potential, because of natural or anthropogenic causes. Forest extension above the treeline depends on the ability of trees to establish in the alpine environment. This ability may be limited by different factors, such as low temperatures, excess solar radiation, competition, soil properties, dispersal ability, and fires. In this paper we address the following two questions: Do trees regenerate above the present treeline, and what are the inhibiting factors for tree establishment? To answer these questions we described the spatial pattern of recent tree establishment below and above the present treeline in northern Ecuador. Also, we experimentally transplanted seedlings into the alpine vegetation (páramo) and the forest, and investigated the effect of shade, neighboring plants, and substrate on their survival. The number of naturally occurring tree sprouts (seedlings, saplings and ramets) was highest just outside the forest, and decreased with distance to the forest edge. However, only two species that were radiation-tolerant made up these high numbers, while other species were rare or absent in the páramo. In the forest, the species diversity of sprouts was high and the abundance per species was relatively low. The transplanted seedlings survived least in experimental plots without artificial shade where neighboring plants were removed. Seedling survival was highest in artificially shaded plots and in the forest. This shade-dependence of most tree species can strongly slow down forest expansion toward the potential climatic treeline. Due to the presence of radiation-tolerant species, the complete lack of forest expansion probably needs to be ascribed to fire. However, our results show that natural processes can also explain both the low position and the abruptness of tropical treelines.     

极端水文干旱下鄱阳湖浮游动物群落结构特征及其影响因素

2022年鄱阳湖流域发生了特大干旱事件,对鄱阳湖生态环境产生了严重影响。为揭示极端水文干旱年的鄱阳湖浮游动物群落结构特征及其主要影响因素,于2022年1月(冬季)、4月(春季)、7月(夏季)和10月(秋季)对鄱阳湖浮游动物进行了综合调查。本次调查共鉴定出浮游动物70种(轮虫40种、桡足类17种和枝角类13种),丰度和生物量范围分别为0—152.67个/L和0—1.52 mg/L。浮游动物群落结构具有较大的时空差异：在季节上,物种数夏季最多,丰度和生物量呈现夏季最高、秋季最低的特征,干旱季节的Shannon-Wiener多样性指数和优势种组成明显不同于非干旱季节;在空间上,南部湖区的物种数、丰度、生物量高于北部湖区,多样性指数在中部湖区最高、北部湖区最低。极端水文干旱年的物种数、丰度和生物量均明显低于往年同期,但空间上的差异较小。相关性分析和冗余分析结果表明,浮游动物群落结构在干旱季节和非干旱季节的主要影响因素存在明显差异,其中干旱季节浮游动物群落结构主要受水温、水位、硝态氮、氨氮等的共同影响,非干旱季节受化学需氧量和水位的影响较大。总体上,极端水文干旱使得鄱阳湖浮游动物群落结构稳定性较...