Disturbance effects on diversity of epiphytes and moths in a montane forest in Ecuador

We sampled the diversity of epiphytes (lichens, bryophytes, vascular plants) and moths (Geometridae, Arctiidae) in mature and recovering forest and in open vegetation in the montane belt in Ecuador. No uniform pattern of change in species richness was detected among the different taxonomic groups with increasing disturbance. Species richness of epiphytic bryophytes and vascular plants declined significantly from mature forest towards open vegetation. In contrast, species richness of epiphytic lichens did not change with increasing forest alteration, while that of geometrid moths was significantly higher in recovering forest compared with mature forest and open habitats. Arctiidae were significantly more species-rich in recovering forest and open vegetation than mature forest. Hence, for some organisms, modified habitats may play an important role for biodiversity conservation in the Andes, whereas others suffer from habitat disturbance. However, trends of changes in species composition following deforestation were surprisingly concordant across most studied epiphyte and moth taxa.     

Edge and land-use effects on epiphytic lichen diversity in the forest-steppe ecotone of the Mongolian Altai

Epiphytic lichen diversity was studied in forests of Siberian larch (Larix sibirica) in the forest-steppe ecotone of the Mongolian Altai. These forests are utilized for livestock grazing, fuelwood collection and occasional logging by pastoral nomads. The density of nomad households in the proximity of the forests influences epiphytic lichen diversity more strongly than the position of sample trees in the forest interior or at the forest line to the steppe. This suggests that land use exerts a stronger effect on lichen diversity than the distinct gradient in microclimate between the forest interior and the forest edge. The co-occurrence of nitrophytes with anitrophytic acidophytes on a small spatial scale as well as higher N and Ca concentrations and pH values in the bark of larch trees at the forest edge than in the forest interior indicate that moderate livestock grazing increases the epiphytic lichen diversity due to an increase of the diversity of chemically different microhabitats. Preference of many lichen species (and of rare species in particular) for overmature and decaying trees suggests that logging and fuelwood collection has adverse effects on epiphytic lichen diversity. This adverse effect is likely to be more crucial for lichen diversity than the putatively positive effect of livestock grazing, since more lichens with a preference for old and decaying trees than for nitrogen-enriched bark were found. The present study is the first one investigating the impact of pastoral nomadism in Central Asia on epiphyte diversity.     

Forest edge-interior differentiation in the epiphytic lichen diversity of the forest steppe in the Khangai Mountains,Mongolia

Aims The effects of traditional land use by mobile livestock keepers on biodiversity in forest steppe ecotones are insufficiently studied. Epiphytes are an important part of forest plant diversity. Here we analyze differences in the diversity and composition of the epiphytic lichen vegetation between the edge and the interior of Siberian larch forests in the Khangai Mountains, western Mongolia, which are highly subdivided into patches. We asked whether the epiphytic lichen vegetation at the forest edge differs significantly from that in the interior, whether the edge is inhabited by more nitrophilous species than the interior and whether the density of nomad camps around the forest affects epiphytic lichen diversity.Methods Cover percentages of epiphytic lichen species were recorded from 20 trees per plot on 6 plots in the interior and 6 plots at the edge of Larix sibirica forests. The position of nomad summer camps was surveyed using Global Positioning System. Data were analyzed with pairwise significance tests, analysis of similarities, nonmetric multidimensional scaling and canonical correspondence analysis.Important findings The composition of the epiphytic lichen vegetation clearly differed between the two habitats, with more species being more frequent at the edge than in the interior. However, there was no difference in species richness (α-diversity). The epiphyte vegetation at the edge was more uniform and characterized by lower variation of tree-level α-diversity and lower β-diversity than in the interior. At the edge, only nitrophytic lichens were dominant, whereas in the interior, nitrophytes and acidophytes were among the dominant species. This pattern is probably attributable to the spatial heterogeneity of the intensity of forest grazing and was shown to be influenced by the density of nomad summer camps in the vicinity of the forests. Tree-level α-diversity increased with stem diameter, but high-diameter trees were rare. The results suggest that the present level of forest patchiness and the effect of forest grazing increases the diversity of epiphytic lichens on the landscape level, while logging of high-diameter trees reduces lichen diversity.     

Patterns of biodiverse,understudied groups do not mirror those of the surrogate groups that set conservation priorities: a case study from the Mid-Atlantic Coastal Plain of eastern North America

We conducted biodiversity inventories of lichens, woody plants, and sedges at 32 sites on the Mid-Atlantic Coastal Plain of eastern North America between November 2012 and June 2015. Each site comprised a single, uniform habitat, consisting of either Coastal Plain Floodplain forest, Coastal Plain Flatwood swamp, Coastal Plain Oak-Pine forest, Maritime forest, Mixed Mesic Hardwood forest, or Tidal forest. We compared alpha diversity and community assemblages of each organismal group across the sites, and compared selected minimal reserve sets in order to visualize biodiversity patterns and assess whether specific components of vascular plants (sedges and woody plants) serve as an effective surrogate for lichens. Woody plants provide a direct substrate for lichen growth, but there is no significant correlation between the alpha diversity of these groups. For conserving maximal species richness among the studied groups, lichens outperform the sedges and woody plants as the best surrogate group for building minimum reserve sets, even though vascular plants are more commonly used as a surrogate. Likewise, sedge alpha diversity does not correlate with lichens, or with woody plants. Although no group is an effective indicator for high alpha diversity sites of other organisms, a significant correlation between the community assemblages of lichens and woody plants suggests that protecting varied types of plant communities might serve as a workable surrogate for protecting lichens. The lack of congruence between species richness patterns across organismal groups suggests that the mechanisms that shape patterns of diversity are not identical, and that identifying and incorporating specific biodiversity indicators for understudied groups in conservation policy is necessary to ensure their protection.     

Edge effects on epiphytic lichen diversity in the forest-steppe of the Kazakh Altai

Background: Forests in forest-steppe ecotones are usually highly fragmented and much of the forested area is exposed to climate and land-use-related edge effects.

Aim: To test the hypothesis that the epiphytic lichen diversity at the forest edges was reduced compared with that in the forest interior, and to analyse lichen diversity in comparison with the more highly elevated and more continental Mongolian Altai.

Methods: Six plots each in the interior and the edge with a total of 240 Larix sibirica trees were studied in the Katon-Karagai National Park, East Kazakhstan.

Results: Species richness and evenness at the tree level were higher in the interior than at the edge. The epiphytic lichen diversity in the forest interior was similar in the Kazakh and Mongolian Altai, whereas that at the forest edge was lower in the Mongolian Altai.

Conclusions: Strong degradation of the forest edges in the Kazakh Altai is the probable cause of the reduced epiphytic lichen diversity compared with the interior. The similar species richness in the forest interiors of the Kazakh and Mongolian Altai suggests that the differences at the forest edge are probably, at least partly, due to different land-use regimes and not to differences in macroclimate.     

Epiphytic lichens as indicators of grazing pressure in the Mongolian forest-steppe

The ecological impact of the traditional land use by pastoral nomads on forest ecosystems is little studied. We analyzed the influence of livestock density on epiphytic lichen diversity in larch forests of the Mongolian forest-steppe, which we selected as a case example because pastoral nomadism is here most widespread within Central Asia. Canonical correspondence analysis showed that the epiphytic lichen vegetation was strongly influenced by the livestock density within a radius of 1 km around the sampled forests. Goats together with horses were most significant at shaping lichen vegetation in the forest edges as were horses alone in the forest interiors. This result matches with the results of interviews with 169 herder families and own field observations, which substantiate that goats preferably graze at the edges, whereas horses often browse the interiors. The livestock impact is thought to be primarily exerted through fertilization by the animals and mechanical abrasion. Based on an indicator species analyses, we propose to use epiphytic lichens as indicators of the grazing impact at different livestock densities in the Mongolian forest-steppe. The proposed indication system can be used as a tool for the rapid assessment of the livestock grazing impact. It has the advantage that it is thought to average the livestock impact of several years, which is important with regard to the nomadic style of livestock husbandry. The use of lichens as indicator species can at least partly substitute the time-consuming interviewing of the herder families to assess livestock densities and their impact on forest biodiversity. The proposed indicator system could thus be used as a planning tool for purposes of nature conservation.     

亚热带不同树种组成森林中土壤甲螨群落结构特征: 以江西新岗山为例

在全球环境变化的大背景下, 生物多样性丧失日益加剧。土壤动物作为生物多样性重要组成之一, 受到广泛的关注。位于我国江西省新岗山的亚热带森林生物多样性与生态系统功能实验样地(BEF-China)是全世界25个森林生物多样性控制实验样地之一。本研究自2019年9月至2022年4月在BEF-China两个不同树种组成的样地(A样地和B样地)内采样, 共获得甲螨23,704头, 隶属于34科50属61种。本文分析和对比了两个样地内甲螨群落结构的差异, 及其多度、物种丰富度、Shannon多样性指数的季节性差异; 通过Pearson检验探讨了甲螨多度与环境因子的关系。结果表明: 在A、B两个不同树种组成的森林生态系统内, 土壤甲螨群落结构及其季节动态具有显著差异。具体表现在: A样地奥甲螨科、罗甲螨科、若甲螨科和尖棱甲螨科的相对多度高于B样地; B样地菌甲螨科、盖头甲螨科和礼服甲螨科的相对多度高于A样地。A样地中夏季和秋季甲螨多度、物种丰富度和Shannon多样性指数显著低于春季和冬季; 而B样地中秋季甲螨多度和物种丰富度与春季差异不显著。Pearson检验结果显示, 凋落物木质素含量与单翼甲螨科和菌甲螨科多度呈负相关关系, 而与奥甲螨科多度呈正相关关系。菌甲螨科多度与土壤和凋落物同一理化因子的相关性基本相同(碳氮比除外), 但与凋落物碳氮比呈正相关关系而与土壤碳氮比呈负相关关系。     

Exploring potential biodiversity indicators in boreal forests

The present study evaluates indicators in Swedish spruce forests. We ask whether different species groups co-vary in their occurrence and to what extent species richness and composition is predictable from habitat structures. We studied 10 boreal spruce forest stands constituting a gradient in degree of selective logging. Occurrences of vascular plants, bryophytes, epiphytic lichens and wood-inhabiting fungi as well as habitat structures was inventoried. In addition, in five of the stands, beetles were sampled with windows traps. Total species richness was correlated with several habitat factors, mainly particular substrates and degree of forestry impact. However, the richness of a set of species regularly used as indicators did not correlate with habitat factors. Correlation in species richness among different organism groups were few and scale dependent. Only lichens and vascular plants formed nested subset patterns (i.e. species composition at poorer sites is subsets of the species present at richer sites) among the study sites. The study shows that in this forest type one cannot a priori assume that richness in one group of species correlated with richness in other, and measures of single habitat features may be relevant only to particular groups of species. Instead, monitoring and inventories should be based on a set of factors reflecting important aspects for different groups of organisms and if indicator species are to be used these should be chosen from several species groups.     

Tree and stand level variables influencing diversity of lichens on temperate broad-leaved trees in boreo-nemoral floodplain forests

Tree and stand level variables affecting the species richness, cover and composition of epiphytic lichens on temperate broad-leaved trees (Fraxinus excelsior, Quercus robur, Tilia cordata, Ulmus glabra, and U. laevis) were analysed in floodplain forest stands in Estonia. The effect of tree species, substrate characteristics, and stand and regional variables were tested by partial canonical correspondence analysis (pCCA) and by general linear mixed models (GLMM). The most pronounced factors affecting the species richness, cover and composition of epiphytic lichens are acidity of tree bark, bryophyte cover and circumference of tree stems. Stand level characteristics have less effects on the species richness of epiphytic lichens, however, lichen cover and composition was influenced by stand age and light availability. The boreo-nemoral floodplain forests represent valuable habitats for epiphytic lichens. As substrate-related factors influence the species diversity of lichens on temperate broad-leaved trees differently, it is important to consider the effect of each tree species in biodiversity and conservation studies of lichens. Nomenclature Randlane et al. (2007) for lichens; Leht (2007) for vascular plants.     

Scale dependent diversity patterns in arboreal and terrestrial oribatid mite (Acari: Oribatida) communities

In naturally fragmented, isolated, or patchily distributed habitats that contain non‐vagile organisms, we expect dispersal to be limited, and patterns of diversity to differ from similar, yet continuous habitats. We explored the alpha‐beta‐gamma relationship and community composition of oribatid mites (Acari: Oribatida) inhabiting spatially discrete canopy suspended soils, and compared the patterns of diversity with the continuous forest floor soils over two years. We explored dispersal limitation for oribatid mites in the canopy by using additive partitioning of species richness at multiple spatial scales. ANOSIM was used to demonstrate differences in oribatid mite community composition between the canopy and forest floor habitats over different sampling periods. Community composition of oribatid mites differed significantly between canopy and forest floor habitats, by season and yearly sampling period. Oribatid mite richness and abundance were positively correlated with substrate moisture content, particularly in the canopy. Richness and abundance of ground oribatid mites was greater in September than in June, a trend that is reversed in the canopy, suggesting canopy oribatid mite species may have altered life histories to take advantage of earlier moisture conditions. Alpha diversity of oribatid mites in the canopy was lower than the ground at all sampling levels, and not significantly different from a random distribution in either habitat. Beta diversity was greater than expected from a random distribution at the patch‐ and tree‐level in the canopy suggesting dispersal limitation associated with physical tree‐to‐tree dispersal barriers, and limited dispersal among patches within a tree. Beta diversity at the tree‐level was the largest contribution to overall species richness in both canopy and ground habitats, and was also greater than expected on the ground. These results suggest that factors other than physical dispersal barriers, such as aggregation, habitat availability, and environmental factors (moisture), may limit the distribution of species in both habitats.     

Community structure,trophic position and reproductive mode of soil and bark-living oribatid mites in an alpine grassland ecosystem

The community structure, stable isotope ratios (¹⁵N/¹⁴N, ¹³C/¹²C) and reproductive mode of oribatid mites (Acari, Oribatida) were investigated in four habitats (upper tree bark, lower tree bark, dry grassland soil, forest soil) at two sites in the Central Alps (Tyrol, Austria). We hypothesized that community structure and trophic position of oribatid mites of dry grassland soils and bark of trees are similar since these habitats have similar abiotic characteristics (open, dry) compared with forest soil. Further, we hypothesized that derived taxa of oribatid mites reproducing sexually dominate on the bark of trees since species in this habitat consume living resources such as lichens. In contrast to our hypothesis, the community structure of oribatid mites differed among grassland, forest and bark indicating the existence of niche differentiation in the respective oribatid mite species. In agreement with our hypothesis, sexually reproducing taxa of oribatid mites dominated on the bark of trees whereas parthenogenetic species were more frequent in soil. Several species of bark-living oribatid mites had stable isotope signatures that were similar to lichens indicating that they feed on lichens. However, nine species that frequently occurred on tree bark did not feed on lichens according to their stable isotope signatures. No oribatid mite species could be ascribed to moss feeding. We conclude that sexual reproduction served as preadaptation for oribatid mites allowing them to exploit new habitats and new resources on the bark of trees. Abiotic factors likely are of limited importance for bark-living oribatid mites since harsh abiotic conditions are assumed to favor parthenogenesis.     

喀斯特小流域栓皮栎林土壤螨类群落结构特征

为比较石漠化环境与喀斯特森林土壤螨类的群落结构差异,对贵州喀斯特地区朝营小流域栓皮栎林的土壤螨类群落结构本底进行了研究,经2014年各季节的4次调查,共发现土壤螨类3目54科83属.对螨类属数、个体数量、个体密度、Shannon多样性指数(H)、Margalef丰富度指数(SR)、Pielou均匀性指数(J)、捕食性螨类成熟度指数(MI)、甲螨MGP类群和甲螨营养结构等进行了分析.结果表明:土壤螨类在类群属数和个体数量上均以甲螨亚目的属占优势,夏季和秋季具有丰富的属数、较高的个体密度与多样性,春季和秋季具有丰富的个体数量,群落分布具有明显的表聚性.捕食性螨类夏季生态类群以K选择型为主,其他季节以r选择型为主;甲螨生态类群主要为P型和O型,缝甲螨属、异珠足甲螨属和合若甲螨属等属构成了栓皮栎林土壤螨类的营养功能集团.研究表明,该区山毛榉林与其他地区山毛榉林、其他不同类型森林的土壤螨类主要类群存在差异,其中含丰富属组成的派伦螨科、厉螨科、奥甲螨科和单翼甲螨科以及多奥甲螨属、派伦满属、菌甲螨属和单翼甲螨属等数量上占优势的类群属可作为山毛榉林土壤环境的生物指示.     

Decomposing logs increase oribatid mite assemblage diversity in mixedwood boreal forest

The removal of timber during harvesting substantially reduces important invertebrate habitat, most noticeably microhabitats associated with fallen trees. Oribatid mite diversity in downed woody material (DWM) using species-level data has not been well studied. We investigated the influence of decaying logs on the spatial distribution of oribatid mites on the forest floor at the sylviculture et aménagement forestiers écosystémique (SAFE) research station in the Abitibi region in NW Québec. In June 2006, six aspen logs were selected for study, and samples were taken at three distances for each log: directly on top of the log (ON), directly beside the log (ADJ) and at least one metre away from the log and any other fallen wood (AWAY). Samples ON logs consisted of a litter layer sample, an upper wood sample and an inner wood sample. Samples at the ADJ and AWAY distances consisted of litter samples and soil cores. The highest species richness was collected ON logs, and logs harboured a distinct oribatid species composition compared to nearby forest floor. There were species-specific changes in abundance with increasing distance away from DWM, which indicates an influence of DWM in structuring oribatid assemblages on the forest floor. Additionally, each layer (litter, wood and soil) exhibited a unique species composition and hosted a different diversity of oribatid mites. This study further highlights the importance of DWM to forest biodiversity by creating habitat for unique assemblages of oribatid mites.     

Intensive agriculture reduces soil biodiversity across Europe

Soil biodiversity plays a key role in regulating the processes that underpin the delivery of ecosystem goods and services in terrestrial ecosystems. Agricultural intensification is known to change the diversity of individual groups of soil biota, but less is known about how intensification affects biodiversity of the soil food web as a whole, and whether or not these effects may be generalized across regions. We examined biodiversity in soil food webs from grasslands, extensive, and intensive rotations in four agricultural regions across Europe: in Sweden, the UK, the Czech Republic and Greece. Effects of land‐use intensity were quantified based on structure and diversity among functional groups in the soil food web, as well as on community‐weighted mean body mass of soil fauna. We also elucidate land‐use intensity effects on diversity of taxonomic units within taxonomic groups of soil fauna. We found that between regions soil food web diversity measures were variable, but that increasing land‐use intensity caused highly consistent responses. In particular, land‐use intensification reduced the complexity in the soil food webs, as well as the community‐weighted mean body mass of soil fauna. In all regions across Europe, species richness of earthworms, Collembolans, and oribatid mites was negatively affected by increased land‐use intensity. The taxonomic distinctness, which is a measure of taxonomic relatedness of species in a community that is independent of species richness, was also reduced by land‐use intensification. We conclude that intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms. Land‐use intensification results in fewer functional groups of soil biota with fewer and taxonomically more closely related species. We discuss how these changes in soil biodiversity due to land‐use intensification may threaten the functioning of soil in agricultural production systems.     

Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida)

Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.     

A survey method for assessing the richness of epiphytic lichens using growth forms

The species richness of epiphytic lichens is continuously decreasing by degradation and loss of habitat. Considering that taxonomic identification of all species is time and resource consuming, rapid assessment methods to extrapolate the total number of species are needed for practical conservation. This paper describes an alternative method using the correlation between lichens growth forms and species richness. The study was conducted in 406 forest stands located in Central Spain, covering a wide range of mediterranean-climate ecosystem regions, management intensity levels, canopy cover conditions, and tree sizes. The presence/absence of epiphytic lichens was determined in 6090 trees, which were dominated by oak species (Quercus ilex, Q. faginea, and Q. pyrenaica). In all type of forests, the diversity of growth forms was positively correlated with the total epiphytic lichen richness. In all cases, species richness increased in non-managed forest stands with dense canopies. Thus, we propose the use of lichen growth forms as a helpful surrogate of species richness to detect potentially conservation priority areas in the Mediterranean region.     

Different responses of plants and herbivore insects to a gradient of vegetation height: an indicator of the vertebrate grazing intensity and successional age

Empirical studies have suggested that species richness of grassland insects usually decreases under grazing management. By contrast, grazing has been shown to increase the species density and richness of vascular plants, especially on productive soils. In order to test the suggested differences in response to management between plants and insects, we simultaneously studied species richness of vascular plants and their insect herbivores, butterflies and moths, in 68 semi-natural grasslands with varying grazing intensity and frequency in SW Finland. Species richness of plants and insects was for the first time related to a quantitative measure of disturbance intensity and successional age, mean vegetation height, by using generalized additive models (GAM). The effects of soil nutrients on vegetation height were accounted for by using phosphorus concentration as a productivity surrogate.
The results showed that species richness of butterflies and moths peaked in taller vegetation compared with vascular plants, corresponding to a lower disturbance intensity and increasing time since abandonment. These patterns are discussed in the light of two hypotheses, the "structural diversity hypothesis" and "dynamic equilibrium model" of Huston, both suggesting a weaker disturbance tolerance of insects compared with plants. Butterflies and moths which are specialists in their larval host-plant use (monophagous and oligophagous species) preferred lower vegetation (higher disturbances) compared with generalists (polyphagous species), as predicted by Huston's model. This difference indicates a stronger relationship with plant species richness for specialist than for generalist butterflies and moths. Our results support the application of regionally and temporally varying grazing intensities in grassland conservation management.     

云南哀牢山原生林及次生林群落附生地衣物种多样性与分布

附生地衣是森林附生植物的重要类群之一, 在维护森林生态系统的物种多样性以及水分和养分循环等方面发挥着重要作用。作者于2005年12月至2006年5月利用树干取样法调查了云南哀牢山徐家坝地区原生山地常绿阔叶林及其次生群落栎类萌生林、滇山杨(Populus bonatii)林和花椒(Zanthoxylum bungeanum)人工林中525株不同种类和径级树木距地面 0–2.0 m处附生地衣的组成和分布, 并收集了各个群落地面上凋落的地衣, 分析了林冠层附生地衣的物种组成。研究结果表明, 该区森林中附生地衣物种比较丰富。共收集到附生地衣61种, 分属17科29属, 其中原生林、栎类萌生林、滇山杨林和花椒人工林分别有51、53、46和23种。在树干距地面 0–2.0 m位置, 各群落中的附生地衣组成明显不同;但在林冠层中, 各群落内的附生地衣基本相似。原生林中附生地衣种类较多, 但分布不均匀。树干附生地衣的Shannon-Wiener和Simpson多样性指数以栎类萌生林最高, 分别为2.71和0.89;花椒林和滇山杨林次之, 分别为2.43–2.45和0.88–0.89;原生林最低, 为1.25和0.67。树干方位、宿主种类和宿主径级等都对附生地衣的物种组成和多样性有着重要影响, 附生地衣更多地出现于树干南向方位, 云南越桔(Vaccinium duclouxii)的附生地衣最为丰富, 胸径5.0–25.0 cm的树木上附生地衣较多。哀牢山山地森林群落中丰富的附生地衣种类及物种多样性在维系本区山地森林生态系统生物多样性格局方面具有重要的作用。     

One taxon does not fit all: Herb-layer diversity and stand structural complexity are weak predictors of biodiversity in Fagus sylvatica forests

Since adequate information on the distribution of biodiversity is hardly achievable, biodiversity indicators are necessary to support the management of ecosystems. These surrogates assume that either some habitat features, or the biodiversity patterns observed in a well-known taxon, can be used as a proxy of the diversity of one or more target taxa. Nevertheless, at least for certain taxa, the validity of this assumption has not yet been sufficiently demonstrated.We investigated the effectiveness of both a habitat- and a taxa-based surrogate in six European beech forests in the Apennines. Particularly, we tested: (1) whether the stand structural complexity and the herb-layer species richness were good predictors of the fine-scale patterns of species richness of five groups of forest-dwelling organisms (beetles, saproxylic and epigeous fungi, birds and epiphytic lichens); and (2) the cross-taxon congruence in species complementarity and composition between herb-layer plants and the target taxa.We used Generalized Linear Mixed Models (GLMMs), accumulation curves and Procrustes analysis to evaluate the effectiveness of these surrogates when species richness, complementarity and composition were considered, respectively.Our results provided a limited support to the hypothesis that the herb-layer plants and the stand structural complexity were good surrogates of the target taxa. Although the richness of the herb-layer plants received a stronger support from the data than structural complexity as a predictor for the general patterns of species richness, the overall magnitude of this effect was weak and distinct taxa responded differently. For instance, for increasing levels of herb-layer richness, the richness of lichens showed a marked increase, while the richness of saproxylic fungi decreased. We also found significantly similar complementarity patterns between the herb-layer plants and beetles, as well as a significant congruence in species composition between herb-layer plants and saproxylic fungi. Finally, when different stand structural attributes were considered singularly, only the total amount of deadwood received support from the data as a predictor of the overall species richness.At the fine scale of this study, herb-layer plants and stand structural complexity did not prove to be effective surrogates of multi-taxon biodiversity in well-preserved southern European beech forests. Rather than on weak surrogates, these results suggest that sound conservation decisions should be supported by the information provided by comprehensive multi-taxonomic assessments of forest biodiversity.     

Threatened species in a vanishing habitat: plants and invertebrates in calcareous grasslands in the Swiss Jura mountains

We examined the diversity of vascular plants, butterflies, grasshoppers, gastropods and carabid beetles in three calcareous grasslands in the northwestern Swiss Jura mountains, a habitat type that has decreased dramatically during the recent decades. As many as 58 species (ca 22%) of the 266 collected are listed as threatened in northern Switzerland. The number of threatened species ranged from 27 to 49 per site, and 26 species occurred in only one of the three grasslands. The species richness of butterflies and vascular plants correlated positively among the grasslands, while the species richness of other groups did not covary. An index of complementarity indicated that the species compositions (including non-threatened species, and spiders and oribatid mites) of the groups varied greatly among the grasslands. In addition, herbivorous groups were more widely distributed than predators among the three grasslands. Due to this variation in species composition none of the three sites c an substitute for the others, if the biodiversity of these grasslands is to be maintained. Furthermore, the taxonomic groups studied are poor indicators of each others' diversity. Consequently, we support the shopping basket approach to conservation evaluation, i.e. measuring species richness, species composition and complementarity of several groups instead of just one.