Exploring the relationship between macrofungi diversity, abundance, and vascular plant diversity in semi-natural and managed forests in north-east Hungary

The diversity of easy-to-study organisms (e.g. vascular plants) is often used as a proxy for the diversity of other organisms whose investigation needs more effort, time and specialist knowledge. Some previous studies have found positive relationships between plant and macrofungal diversity and thus support this approach, while others question this practice. Our aim was to explore the possibility of using plant diversity as surrogate for macrofungal diversity in the forests of the Pannonian ecoregion. A total of 19 permanent plots in north-east Hungary were sampled for vascular plants and macrofungi. The effect on macrofungal abundance and diversity, as well as degradation level, of plant evenness and richness was tested using generalized linear models. Species richness of macrofungi assemblages proved to be independent of the diversity and naturalness of vascular plant communities; however, there was congruence in the composition of the two communities. In contrast to diversity, macrofungi abundance was significantly negatively correlated to plant species richness. There was a hump-backed relationship between the abundance of terricolous macrofungi and the degradation level estimated on the basis of the occurrence of vascular plants, although degradation did not influence the abundance of lignicolous macrofungi. Our results question the reliability of decisions on nature conservation actions based on a few groups of easy-to-observe organisms, and underline the necessity of studying as wide a range of taxonomic groups as possible.     

Predator Assemblage Structure and Temporal Variability of Species Richness and Abundance in Forests of High Tree Diversity

Predators significantly affect ecosystem functions, but our understanding of to what extent findings can be transferred from experiments and low‐diversity systems to highly diverse, natural ecosystems is limited. With a particular threat of biodiversity loss at higher trophic levels, however, knowledge of spatial and temporal patterns in predator assemblages and their interrelations with lower trophic levels is essential for assessing effects of trophic interactions and advancing biodiversity conservation in these ecosystems. We analyzed spatial and temporal variability of spider assemblages in tree species‐rich subtropical forests in China, across 27 study plots varying in woody plant diversity and stand age. Despite effects of woody plant richness on spider assemblage structure, neither habitat specificity nor temporal variability of spider richness and abundance were influenced. Rather, variability increased with forest age, probably related to successional changes in spider assemblages. Our results indicate that woody plant richness and theory predicting increasing predator diversity with increasing plant diversity do not necessarily play a major role for spatial and temporal dynamics of predator assemblages in such plant species‐rich forests. Diversity effects on biotic or abiotic habitat conditions might be less pronounced across our gradient from medium to high plant diversity than in previously studied less diverse systems, and bottom‐up effects might level out at high plant diversity. Instead, our study highlights the importance of overall (diversity‐independent) environmental heterogeneity in shaping spider assemblages and, as indicated by a high species turnover between plots, as a crucial factor for biodiversity conservation at a regional scale in these subtropical forests.     

Conservation of invertebrate biodiversity on a mountain in a global biodiversity hotspot,Cape Floral Region

Mountains present particular challenges for biodiversity conservation. Table Mountain is a significant mountain in a global biodiversity hotspot, the Cape Floristic Region. It has outstanding angiosperm diversity and endemism. Yet, aerial and foliage invertebrates in the area have been poorly studied, despite their importance as pollinators and predators. These plant and invertebrate assemblages are under great pressure from human disturbance. Aerial and foliage invertebrates were sampled with a range of techniques. Sites were chosen to make comparisons between vegetation structure and type, elevation and aspect. In total, 216 species from 63 families and 14 orders were recorded. Vegetation structure (fynbos or forest) and elevation were the most important environmental variables for both aerial and foliage invertebrates. Peak time for aerial invertebrate abundance was spring and summer in the fynbos and spring in the forests, while the foliage invertebrates showed very little seasonal variation. There was no correlation between the diversity of aerial and foliage invertebrates. When these results were compared with others on epigaeic invertebrates, it became clear that epigaeic and aerial invertebrates are not correlated, while epigaeic and foliage invertebrates were only partially correlated, but not sufficiently so to consider one as a reliable estimator of the other. The management pointer from this study is that sites at all elevations are vital for the conservation of biodiversity on Table Mountain. Both the aerial and epigaeic/foliage invertebrate assemblages will need to be monitored separately to maintain the mountain’s conservation status.     

Disentangling the role of management,vegetation structure,and plant quality for Orthoptera in lowland meadows

Seminatural grasslands provide habitats for various species and are important for biodiversity conservation. The understanding of the diverse responses of species and traits to different grassland managenient methods is therefore urgently needed. We disentangled the role of grassland management (fertilization and irrigation), vegetation structure (biomass, sward height) and plant quality (protein and fiber content) for Orthoptera communities in lowland hay meadows in Germany. We found vegetation structure to be the most important environmental category in explaining community structure of Orthoptera (species richness, total individuals, fiinctional diversity and species composition). Intensively used meadows (fertilized, irrigated, high plant biomass) were characterized by assemblages with few species, low functional diversity, and low conservation value. Thereby, the relatively moderate fertilizer inputs in our study system of up to -75 kg N/ha/year reduced functional diversity of Orthoptera, while this negative effect of fertilization was not detectable when solely considering taxonomic aspects. We found strong support for a prominent role of plant quality in shaping Orthoptera communities and especially the trait composition. Our findings demonstrate the usefulness of considering both taxonomic and functional comp on ents (functio nal diversity) in biodiversity research and we suggest a stronger involvement of plant quality measures in Orthoptera studies.     

Anthropogenic threats can have cascading homogenizing effects on the phylogenetic and functional diversity of tropical ecosystems

Determining the mechanisms that underlie species distributions and assemblages is necessary to effectively preserve biodiversity. This cannot be accomplished by examining a single taxonomic group, as communities comprise a plethora of interactions across species and trophic levels. Here, we examine the patterns and relationships among plant, mammal, and bird diversity in Madagascar, a hotspot of biodiversity and endemism, across taxonomic, phylogenetic, and functional axes. We found that plant community diversity and structure are shaped by geography and climate, and have significant influences on the taxonomic, phylogenetic and functional diversity of mammals and birds. Patterns of primate diversity, in particular, were strongly correlated with patterns of plant diversity. Furthermore, our findings suggest that plant and animal communities could become more phylogenetically and functionally clustered in the future, leading to homogenization of the flora and fauna. These results underscore the importance and need of multi‐taxon approaches to conservation, given that even small threats to plant diversity can have significant cascading effects on mammalian and avian community diversity, structure, and function.     

Relating macrofungal diversity and forest characteristics in boreal forests in China: Conservation effects,inter‐forest‐type variations,and association decoupling

QuestionHow conservation and forest type affect macrofungal compositional diversity is not well understood. Even less is known about macrofungal associations with plants, soils, and geoclimatic conditions.LocationSouthern edge of boreal forest distribution in China, named as Huzhong Nature Reserve.MethodsWe surveyed a total of 72 plots for recording macrofungi, plants, and topography in 2015 and measured soil organic carbon, nitrogen, and bulk density. Effects of conservation and forest types on macrofungi and plants were compared, and their associations were decoupled by structural equation modeling (SEM) and redundancy ordination (RDA).ResultsConservation and forest type largely shaped macrofungal diversity. Most of the macrofungal traits declined with the conservation intensities or peaked at the middle conservation region. Similarly, 91% of macrofungal traits declined or peaked in the middle succession stage of birch‐larch forests. Forest conservation resulted in the observation of sparse, larch‐dominant, larger tree forests. Moreover, the soil outside the Reserve had more water, higher fertility, and lower bulk density, showing miscellaneous wood forest preference. There is a complex association between conservation site characteristics, soils, plants, and macrofungi. Variation partitioning showed that soil N was the top‐one factor explaining the macrofungal variations (10%). As shown in SEM coefficients, conservation effect to macrofungi (1.1–1.2, p < .05) was like those from soils (1.2–1.6, p < .05), but much larger than the effect from plants (0.01–0.14, p > .10). For all tested macrofungal traits, 89%–97% of their variations were from soils, and 5%–21% were from conservation measures, while plants compensated 1%–10% of these effects. Our survey found a total of 207 macrofungal species, and 65 of them are new updates in this Reserve, indicating data shortage for the macrofungi list here.ConclusionOur findings provide new data for the joint conservation of macrofungi and plant communities, highlighting the crucial importance of soil matrix for macrofungal conservation in boreal forests.     

Spatial structure, rock type, and local environmental conditions drive moss and lichen distribution on calcareous boulders

Although mosses and lichens are a relevant component of the biota of rock habitats targeted for biodiversity conservation in Europe, the ecological factors driving their distribution are still poorly known. In this work, we examined the epilithic moss and lichen assemblages colonizing boulders of different types of calcareous rocks co-occurring in the same area in the Italian Alps. The goals were: (1) to evaluate if and to what extent different calcareous rocks host different assemblages; (2) to identify species associated to each rock type; (3) to quantify the relative importance of rock type, local environmental factors, and habitat spatial structure in explaining species distribution. Our results demonstrated that different calcareous rocks host different moss and lichen assemblages with some typical species, indicating that each rock type contributes to the total diversity of both mosses and lichens. Local environmental conditions influenced mosses and not lichens whose distribution is mainly associated to rock type. The patterns of both organism groups were also significantly related to habitat spatial structure, species assemblages tending to have a patchy distribution, which may reflect dispersal dynamics. Our results have implications for conservation: (1) each rock type may play a relevant role in maintaining the overall diversity contributing with unique assemblages and typical species; (2) the patchy distribution of both moss and lichen assemblages should warn from considering rock patches as a monotonous repetition of the same habitat across space.     

Biodiversity in agricultural landscapes: different non-crop habitats increase diversity of ground-dwelling beetles (Coleoptera) but support different communities

Agricultural intensification poses a major threat to the conservation of biodiversity and associated ecosystem services. Since non-crop habitats are regarded as important refuges for farmland biodiversity, various greening measures have been proposed to halt biodiversity loss. However, the effectiveness of these measures for biodiversity conservation is still under debate. Therefore, we here compared ground-dwelling beetle (Coleoptera) assemblages of different non-crop habitats (field margins, set-aside fields sown with wildflowers, and permanent grassland fallows) and wheat fields within an intensively used agricultural landscape in western Germany. Taxonomic diversity of Carabidae, Staphylinidae and other coleopteran families and their conservation value were higher in all non-crop habitats than on wheat fields. Surprisingly, though, different types of non-crop habitats did not differ in species richness or the number of threatened species. Thus, field margins and sown wildflower fields were as effective in promoting beetle diversity as grassland fallows. However, different non-crop habitats supported different species assemblages, and several species, in particular especially large ones, were restricted to grassland fallows. These results suggest that different greening measures are effective in promoting the biodiversity of beetles, and that permanent grassland fallows are essential for nature conservation. The fact that habitat types harbored different assemblages stresses the need to combine a variety of greening measures to yield the highest benefit for biodiversity.

     

Limited habitat and conservation value of a young artificial reef

Loss and degradation of natural habitats and their biodiversity may, arguably, be mitigated or compensated through the creation of human-engineered habitats: the underlying conservation tenet is that these artificial habitats compensate for diminished diversity caused by human impacts at local or regional scales. This approach is widely used in the sea by purposefully scuttling ships to create artificial reefs, but its performance as a conservation tool is seldom critically examined in these situations. Here we test if the diversity of sessile invertebrate assemblages on a large, but young (3 years), artificial reef, created by sinking a 133 m long battle ship off Eastern Australia, can mimic that of nearby natural reefs. We use this system as a model to test whether this artificial reef can form compensatory habitat of comparable quality and levels of biodiversity. Our assessment is based on the abundance, species richness, and species composition of sessile invertebrate assemblages, including corals. Despite some signs that temporal trajectories of ecological metrics, such as cover, began to approach natural conditions after 3 years, the ecological structure of sessile invertebrate assemblages on this young wreck remained fundamentally different from those on nearby natural reefs. In particular, large, long-lived corals were abundant on natural rocky reefs, but were rare and covered little area on the young wreck. These data demonstrate that when trajectories to community convergence with natural habitats are prolonged, as may be the case here, any compensatory effects of artificial habitats will have a considerable time lag. Such lags have implications for appraising the conservation value of wrecks and artificial reefs, and they emphasize the need to explicitly acknowledge temporal dynamics when using artificial habitats as complementary conservation tools to augment larger conservation efforts on natural systems.     

The role of farm structure on bird assemblages around a Kenyan tropical rainforest

Although it is clear that the farmlands neighbouring fragmented forests are utilized by some forest birds, it is not clear how birds in general respond to farmland habitat mosaic. An effort was made to determine how bird density and foraging assemblages were influenced by farm structural characteristics and distance from forest edge. Thirty farms up to a distance of 12 km around Kakamega forest in western Kenya were studied. Farm structure entailed size, hedge volume, habitat heterogeneity, woody plant density, plant diversity and crop cover. Birds were surveyed using line transects and DISTANCE analyses and classified into six feeding guilds and three habitat associations. Size of farms increased away from the forest, as woody plant density, plant diversity, indigenous trees and subsistence crop cover declined. The most important farm structure variable was hedge volume, which enhanced bird species richness, richness of shrub‐land bird species and insectivorous bird density (R = 0.58, P < 0.01). Bird density increased with tree density while indigenous trees were suitable for insectivores and nectarivores. There were very few forest bird encounters. Agricultural practices incorporating maintenance of hedges and sound selection of agroforestry trees can enhance conservation of birds on farmland, though, not significantly for forest species.     

Habitat associations of epigeal spiders in upland calcareous grassland landscapes: the importance for conservation

Upland calcareous grassland landscapes are typically comprised of a matrix of calcareous grassland, acid grassland and limestone heath plant communities. This matrix of habitats is produced by a combination of underlying geology, climate and management. These landscapes are typically managed through grazing, with management targeted to maintain particular plant communities in the calcareous grassland habitat, whilst patches of acid grassland and limestone heath are not targeted by conservation management. The biodiversity value of acid grassland and limestone heath patches within the calcareous grassland matrix are unknown. This study provides the first assessment of their biodiversity value by examining aspects of epigeal spider diversity supported by these non-target habitat patches in comparison to calcareous grassland. Spiders were sampled in each habitat from April to August 2014 using pitfall traps across three upland regions in Great Britain. Spider species assemblages were distinct between limestone heath and both grassland types. Distinction in species assemblages are likely due to differences in vegetation structure and microclimate, e.g., humidity, degree of shade. Each habitat type supported several rare species (e.g., Jacksonella falconeri, Agyneta subtilis) revealing the contribution to spider fauna. The distinct spider species assemblage and presence of rare species in limestone heath patches demonstrate their importance in the upland calcareous grassland matrix. This study highlights the value of monitoring biodiversity in non-target habitats within a habitat matrix alongside those that are actively targeted by management.     

A multi-faceted framework of diversity for prioritizing the conservation of fish assemblages

Floodplain waterbodies and their biodiversity are increasingly threatened by human activities. Given the limited resources available to protect them, methods to identify the most valuable areas for biodiversity conservation are urgently needed. In this study, we used freshwater fish assemblages in floodplain waterbodies to propose an innovative method for selecting priority areas based on four aspects of their diversity: taxonomic (i.e. according to species classification), functional (i.e. relationship between species and ecosystem processes), natural heritage (i.e. species threat level), and socio-economic (i.e. species interest to anglers and fishermen) diversity. To quantitatively evaluate those aspects, we selected nine indices derived either from metrics computed at the species level and then combined for each assemblage (species rarity, origin, biodiversity conservation concern, functional uniqueness, functional originality, fishing interest), or from metrics directly computed at the assemblage level (species richness, assemblage rarity, diversity of biological traits). Each of these indices belongs to one of the four aspects of diversity. A synthetic index defined as the sum of the standardized aspects of diversity was used to assess the multi-faceted diversity of fish assemblages. We also investigated whether the two main environmental gradients at the catchment (distance from the sea) and at the floodplain (lateral connectivity of the waterbodies) scales influenced the diversity of fish assemblages, and consequently their potential conservation value. Finally, we propose that the floodplain waterbodies that should be conserved as a priority are those located in the downstream part of the catchment and which have a substantial lateral connectivity with the main channel.     

Factors affecting the structure of Coleoptera assemblages on bracket fungi (Basidiomycota) in a Brazilian forest

Insect–fungal interactions are an important but understudied aspect of tropical forest ecology. Here we present the first large‐scale study of insect communities feeding on the reproductive structures of macrofungi (basidiomes) in the Neotropics. This trophic interaction is not well characterized in most ecosystems; however, beetle consumption of basidiomes is thought to be affected by fungal factors, via mechanisms analogous to those observed in plant–herbivore interactions and in some interactions with fungi as hosts in the Holarctic region. We investigated how the composition of beetle assemblages varies as a function of fungal taxonomic distance, basidiome consistency, and hyphal systems. We collected 367 basidiomes belonging to the orders Polyporales and Hymenochaetales in the subtropical Araucaria angustifolia forest region of southern Brazil, along with any fauna present or without it. Basidiomes were maintained individually in the laboratory in plastic containers for up to three months to allow beetles to develop to adulthood, at which point the beetles were collected. We found that 207 basidiome specimens representing 40 species were associated with beetles. We recorded 447 occurrences of Coleoptera, representing 90 morphospecies from 20 families. We found that assemblages of fungivorous Coleoptera were more similar among more closely related fungi. Furthermore, the beetle assemblages varied as a function of basidiome toughness, which is influenced by sporocarp consistency and hyphal system type. The associations between beetles and basidiomes resemble those reported previously in temperate zones, suggesting continuity in the structure of such associations across a wide latitudinal range.     

Determinants of fine‐scale homogenization and differentiation of native freshwater fish faunas in a Mediterranean Basin: implications for conservation

Aim Increasing threats to freshwater biodiversity are rapidly changing the distinctiveness of regional species pools and local assemblages. Biotic homogenization/differentiation processes are threatening the integrity and persistence of native biodiversity patterns at a range of spatial scales and pose a challenge for effective conservation planning. Here, we evaluate the extent and determinants of fine‐scale alteration in native freshwater fish assemblages among stream reaches throughout a large river basin and consider the implications of these changes for the long‐term conservation of native fishes. Location Guadiana River basin (South‐Western Iberian Peninsula). Methods We quantified the magnitude of change in compositional similarity between observed and reference assemblages and its potential effect on natural patterns of compositional distinctiveness. Reference assemblages were defined as the native species expected to occur naturally (in absence of anthropogenic alterations) and were reconstructed using a multivariate adaptive regression splines predictive model. We also evaluated the role of habitat degradation and introduced species as determinants of biotic homogenization/differentiation. Results We found a significant trend towards homogenization for native fish assemblages. Changes in native fish distributions led to the loss of distinctiveness patterns along natural environmental gradients. Introduced species were the most important factor explaining the homogenization process. Homogenization of native assemblages was stronger in areas close to reservoirs and in lowland reaches where introduced species were more abundant. Main conclusions The implementation of efficient conservation for the maintenance of native fish diversity is seriously threatened by the homogenization processes. The identification of priority areas for conservation is hindered by the fact that the most diverse communities are vanishing, which would require the selection of broader areas to adequately protect all the species. Given the principal role that introduced species play in the homogenization process and their relation with reservoirs, special attention must be paid to mitigating or preventing these threats.     

植物多样性与生态系统土壤保持功能关系及其生态学意义

测定物种丰富度呈梯度变化的半湿润常绿阔叶林不同次生演替阶段小区地表径流、土壤侵蚀和总磷流失及影响这些过程的植物群落郁闭度、个体密度、胸高断面积、植物叶吸附水,分析物种多样性与生态系统土壤保持功能、稳定性及直接影响土壤保持功能的群落结构、树冠截留间的关系。结果表明,在降雨、坡度、坡向、坡位、土壤类型等水土保持影响因子相同条件下,随着各小区物种多样性的增加,地表产流次数不断下降;在3个降雨季节,物种多样性最低的小区产生地表径流77次,而物种多样性最高小区产生地表径流才9次;系列小区地表径流、土壤侵蚀和总磷流失随着物种多样性增加呈幂指数下降;物种多样性最低的小区地表径流、土壤侵蚀和总磷流失分别为960.20 m³·hm^-2·a^-1,11.4 t·hm^-2·a^-1,127.69 kg·hm^-2·a^-1,而物种多样性最高的小区为75.55 m³·hm^-2·a^-1、0.28 t·hm^-2·a^-1、4.71 kg·hm^-2·a^-1,分别相差12、50和25倍;地表径流、土壤侵蚀和总磷流失变异系数也呈幂指数下降,物种多样性最高的小区地表径流、土壤侵蚀和总磷流失的变异系数分别为57.93、187.94和 59.2,而物种多样性最低的小区变异系数高达287.6、534.21、315.47,分别相差4、3和5倍。物种多样性与影响土壤保持功能的群落郁闭度、密度和胸高断面积呈正相关关系。不同演替阶段植物叶吸附水量差异显著,吸附水量最高的演替阶段是次生半湿润常绿阔叶林,为12.28 t·hm^-2·a^-1, 最低是云南松(Pinus yunnanensis)林, 为4.15 t·hm^-2·a^-1。“植物多样性-土壤保持功能相关群落结构因子及树冠截留效应-生态系统土壤保持功能”的耦合关系表明了植物多样性通过植物群落结构削弱了降雨动能,减少了地表径流,减轻了土壤及营养元素的流失,以间接方式调控生态系统土壤保持功能,维持系统营养的持续性,在不同尺度上实现生态系统生产力。物种多样性的提高,促进了生态系统土壤保持功能的稳定性。植物多样性-生态系统土壤保持过程的研究可能是生态系统稳定性研究的好方法。用植物叶吸附水测定可评价群落树冠截留效应。由于植物多样性与生态系统土壤保持功能间存在相关关系,基于植物多样性对生态系统土壤保持功能作用模式,可增进对生命系统和地球系统界面间相互作用关系的了解。     

Influence of land consolidation on aquatic invertebrate communities and their distribution patterns in Korean rice fields

Rice fields, the major cropland in South Korea, provide an important wetland habitat for a diverse wildlife and contribute to biodiversity conservation. On the other hand, land consolidation conducted to increase agricultural production since the 1960s on a nationwide scale in South Korea has frequently been suggested to be one of the factors in the decline of biodiversity in agricultural ecosystems. Negative effects of habitat manipulation such as land consolidation would have influenced paddy field biodiversity, but the degree has not been clearly measured in South Korea. This study evaluated the impacts of land consolidation on the aquatic invertebrate biodiversity and investigated their patterns across the nation. Field sampling for biodiversity and environmental variables were made from 290 sites of paddy field over the country. Aquatic invertebrate communities were clustered into four major clusters showing land consolidation as the main factor and geographic location as the second factor. Species richness and abundance were significantly lower in the land consolidation fields (mean ± s.e., 12.80 ± 0.28 vs 88.89 ± 0.89 and 2027.15 ± 150.84 vs 2573.54 ± 572.16). Shannon diversity index was also significantly lower in land consolidation fields. Our results suggest that land consolidation and spatial location are important for biodiversity and conservation of the aquatic invertebrate assemblages in Korean rice fields.     

Responses of taxonomic distinctness and species diversity indices to anthropogenic impacts and natural environmental gradients in stream macroinvertebrates

1. Many studies have shown traditional species diversity indices to perform poorly in discriminating anthropogenic influences on biodiversity. By contrast, in marine systems, taxonomic distinctness indices that take into account the taxonomic relatedness of species have been shown to discriminate anthropogenic effects. However, few studies have examined the performance of taxonomic distinctness indices in freshwater systems. 2. We studied the performance of four species diversity indices and four taxonomic distinctness indices for detecting anthropogenic effects on stream macroinvertebrate assemblages. Further, we examined the effects of catchment type and area, as well as two variables (pH and total phosphorus) potentially describing anthropogenic perturbation on biodiversity. 3. We found no indications of degraded biodiversity at the putatively disturbed sites. However, species density, rarefied species richness, Shannon's diversity and taxonomic diversity showed higher index values in streams draining mineral as opposed to peatland catchments. 4. Of the major environmental gradients analysed, biodiversity indices showed the strongest relationships with catchment area, lending further support to the importance of stream size for macroinvertebrate biodiversity. Some of the indices also showed weak linear and quadratic relationships to pH and total phosphorus, and residuals from the biodiversity index‐catchment area regressions (i.e. area effect standardized) were more weakly related to pH and total phosphorus than the original index values. 5. There are a number of reasons why the biodiversity indices did not respond to anthropogenic perturbation. First, some natural environmental gradients may mask the effects of perturbation on biodiversity. Secondly, perturbations of riverine ecosystems in our study area may not be strong enough to cause drastic changes in biodiversity. Thirdly, multiple anthropogenic stressors may either increase or decrease biodiversity, and thus the coarse division of sites into reference and altered streams may be an oversimplification. 6. Although neither species diversity nor taxonomic distinctness indices revealed anthropogenic degradation of macroinvertebrate assemblages in this study, the traditional species diversity and taxonomic distinctness indices were very weakly correlated. Therefore, we urge that biodiversity assessment and conservation planning should utilize a number of different indices, as they may provide complementary information about biotic assemblages.     

Structure of ground-dwelling arthropod assemblages in vegetation units of Área Natural Protegida Península Valdés,Patagonia, Argentina

Knowing the spatial variation of insect and arachnid assemblages and their relationship with habitat variables is critical to understand the structure and dynamics of these communities in arid environments. The aim of this paper was to analyze the variation in ground-dwelling arthropod assemblages across three representative vegetation units of the Área Natural Protegida Península Valdés (Patagonia, Argentina). We asked whether environmental differences among representative vegetation units were associated to distinct arthropod assemblages. We selected three plant communities: grass, dwarf-shrub, and shrub steppes, and established three sampling sites within each of them. We measured variables of vegetation structure and soil characteristics and collected the arthropods using 10 pitfall traps per site. We analyzed the structure of arthropod assemblages at both family and ant species taxonomic levels. Each plant community displayed a distinctive assemblage, with differences in diversity, taxa abundance, trophic structure and functional groups of ants. Vegetation variables explained a higher proportion of the variation in the structure of the ground-dwelling arthropod assemblages than the soil variables. This work highlights the importance of the different vegetation units for the conservation of ground-dwelling arthropod biodiversity in Península Valdés.     

Phylogenetic community patterns suggest Central Indian tropical dry forests are structured by montane climate refuges

Aim

We used an eco-phylogenetic approach to investigate the diversity and assembly patterns of tropical dry forests (TDFs) in Central India. We aimed at informing conservation and restoration practices in these anthropogenically disturbed forests by identifying potential habitats of conservation significance and elements of regional biodiversity most vulnerable to human impact and climate change.

Location

Tropical dry forests of Madhya Pradesh, Central India.

Methods

We analysed the species richness, stem density, basal area and phylogenetic structure (standardized effect size of MNTD, MPD, PD and community evolutionary distinctiveness cED) of 117 tree species assemblages distributed across a ~230 to ~940 m elevational gradient. We examined how these community measures and taxonomic (Sørensen) and phylogenetic (UniFrac) beta diversity varied with elevation, precipitation, temperature and climatic stress.

Results

Species richness, phylogenetic diversity, stem density and basal area were positively correlated with elevation, with high-elevation plots exhibiting cooler temperatures, higher precipitation and lower stress. High-elevation assemblages also trended towards greater phylogenetic dispersion, which diminished at lower elevations and in drier, more stressful plots. Phylogenetic turnover was observed across the elevation gradient, and species evolutionary distinctiveness increased at lower elevations and under harsher abiotic conditions.

Main Conclusions

Harsher abiotic conditions at low elevations may act as a selective filter on plant lineages, leading to phylogenetically clustered low-diversity assemblages. These assemblages contained more evolutionarily distinct species that may contribute disproportionately to biodiversity. Conversely, milder abiotic conditions at high elevations may serve as refuges for drought-sensitive species, resulting in more diverse assemblages. Conservation practices that prioritize both high- and low-elevation habitats could promote the persistence of evolutionarily distinct species and areas of high biodiversity within the Central Indian landscape. Establishing connectivity between these habitats may provide a range of climatic conditions for species to retreat to or persist within as climates change.     

Wintering bird communities in newly-formed wetland in the Yangtze River estuary

We compared wintering bird communities and their habitats among three shoals at Jiuduansha, a newly-formed wetland in the Yangtze River estuary. The highest species richness and diversity were recorded in Shangsha, which is the highest shoal, and the highest abundance and lowest species diversity were recorded in Xiasha, which is the lowest shoal. Shangsha had the largest abundance of perching birds whereas Xiasha was the most abundant in waterbirds. Bird assemblages showed different associations with the different habitat types—perching birds were favored by reed (Phragmites australis) communities, shallow water foragers and dabbling ducks preferred sea-bulrush (Scirpus mariqueter) communities, and moist-soil foragers and gulls showed a preference for bare intertidal zones. All bird assemblages, however, avoided the smooth cordgrass (Spartina alterniflora) communities, which are dominated by an alien invasive plant. The composition of avian communities was related to habitat types at the three shoals. Our results suggest that the newly-formed tidelands can provide suitable habitats for waterbirds and that the lower tidelands can attract more waterfowl than the higher tidelands. Because the shoal with low species diversity could have exclusive bird species, conservation efforts should not concentrate only on the area with high species diversity. The estuarine wetlands should be considered as a whole when conservation strategies are designed. The alien invasive plant should, moreover, be effectively controlled, to provide suitable habitats for birds.