Long-term changes in floristic diversity in southern Sweden: palynological richness, vegetation dynamics and land-use

The rarefaction technique is applied to two Holocene pollen sequences (covering the last 12,000 calendar years) from two lakes in southern Sweden. One represents an open agricultural landscape, the other a partly wooded and less cultivated landscape. The inferred palynological richness is interpreted as an approximate measure of floristic diversity at the landscape scale. The overall trend is an increased diversity from the mid-Holocene to the Modern period, which is linked to a parallel rise in human impact. The pattern is similar for the two sites with peaks corresponding to archaeological periods characterised by deforestation and expanding settlement and agriculture. The highest diversity was reached during the Medieval period, about a.d. 1,000–1,400. Declining diversity during the last 200 years characterises the agrarian landscape. These results confirm, for southern Scandinavia, the “intermediate disturbance” hypothesis for biodiversity at the landscape scale and on millennial to century time scales. They have implications for landscape management in modern nature conservation that has the purpose of maintaining and promoting biodiversity.     

A latent threat to biodiversity: consequences of small-scale heterogeneity loss

The threat of homogenisation to biodiversity is generally considered to occur at broad scales or in response to high-intensity impacts. Therefore, most biodiversity studies estimate local average or total species richness rather than local heterogeneity. Here we consider the potential for relative shifts between these different aspects of biodiversity at small spatial scales to be an early warning signal for biodiversity loss. In response to chronic, very low-level pollution, we observed a disjunctive response with gamma diversity (total species richness) and beta diversity (heterogeneity) decreasing while alpha diversity (average species richness) was still increasing. Homogenisation may, therefore, affect biodiversity through thresholds that alter the relationship between the average species richness and its heterogeneity, leading to the potential for regime shifts. Our stressor also had a strong negative effect on rare species, meaning that the purported importance of rare species as “insurance” in the face of environmental change may be overstated.     

Pattern of land mosaics affecting butterfly assemblage at Mt Ikoma, Osaka, Japan

We studied the effects of habitat mosaics on butterfly assemblage on multiple spatial scales: landscape, landscape element, local habitat, and microhabitat, based on the transect counts conducted along a 3.84 km route. The transect route, including 21 local habitats, passed through two distinct areas: 1.65 km of a secondary deciduous Quercus forest and the grove of a shrine in Hiraoka, and 2.19 km of a mosaic of secondary deciduous Quercus forest, grassland, and farmland in Narukawa. The diversity of the landscape elements and species richness were higher in Narukawa than in Hiraoka; the landscape mosaic enhanced the species richness in Narukawa. However, the diversity indices and specialist species (univoltine tree feeder) were decreased in this mosaic landscape. The species richness at local habitats was also increased by the mosaic of microhabitats, such as the herbaceous layer, glade, and mantle in the local habitats, whereas it was decreased by an abundant shrub layer. The ratios of species richness to abundance in the local habitats were lower than expected based on random sampling from the total of Hiraoka and Narukawa. This means that local assemblages were non-random samples from an assemblage on the landscape or regional scale, and were made up by the process of habitat selection of butterfly species in the assemblages on the landscape or regional scale. For conservation of butterfly assemblages, we recommend that woodlands should be kept without fragmentation, but with glades or small grasslands, and with clearance of the shrub layer along the path.     

Indicators for plant species richness in pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) forests of Germany

Forestry is obliged to record as well as maintain and/or enhance biological diversity in forests due to national and international agreements. Accordingly, it is necessary to work out methodological approaches for the assessment of biodiversity in forests. In the study presented here, we focus on the total plant species pool (563 vascular plant and bryophyte species) of pine (Pinus sylvestris L.) forests in NE Germany to identify indicators for plant species richness. We distinguished several groups like “herb”, “grass-like”, “woody”, “endangered”, and “exotic species”, for which we detected indicators for low (class #1), intermediate (class #2), and high (class #3) species numbers. From a total of 84 species, which were identified by a three-step procedure, most indicators were found for class #3. Only few indicators have been revealed for intermediate species numbers, i.e. class #2. With help of Ellenberg’s ecological indicator values and information on the main occurrence in Central European vegetation types and plant communities, respectively, we characterized the indicator species ecologically. The ecological site preferences of the indicator species in general reflect the fact that species richness is highest in base-rich, light, and anthropogenically disturbed pine forests. On the contrary, species-poor forests were revealed by indicators, which mainly occur on acidic sites. It is concluded that a considerable set of indicators for species richness can help facilitate biodiversity assessments in forestry and ecosystem restoration practice. Electronic Supplementary Material  The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

Effects of polyculture and monoculture farming in oil palm smallholdings on tropical fruit‐feeding butterfly diversity

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Towards indicators of butterfly biodiversity based on a multiscale landscape description

The conservation of biodiversity has gained prominence in ecological research for the last decades. Conservation actions require a measure of biodiversity such as species richness, but its assessment is very difficult, even for small areas and therefore the search for surrogates (i.e. indicators) of biodiversity has emerged as an active research topic. We investigated the relationships between butterfly species richness and landscape structure and composition in two pine plantation sites in Southwest France. We assessed the correlation between butterfly species richness and a set of 15 landscape metrics computed for 18 land-uses at 10 different spatial scales. Spatial scales were accounted for by computing landscape metrics for circular buffers with radius ranging from 100 to 1000 m. The joint use of the Partial Least Squares Regression (PLSR) and a stepwise regression procedure revealed strong correlations between butterfly species richness and various landscape metrics in both study sites. The selected landscape metrics differed from one site to another and mostly involved measures of landscape fragmentation. We found a very strong effect of the spatial scale of investigation upon the perception of the landscape–butterfly richness relationship. Our main conclusions are that (i) certain landscape attributes can potentially serve as indicators for butterfly species richness at the landscape scale; (ii) future indicators of biodiversity based on landscape features should consider various spatial scales.     

Effects of spatial heterogeneity on butterfly species richness in Rocky Mountain National Park, CO, USA

We investigated butterfly responses to plot-level characteristics (plant species richness, vegetation height, and range in NDVI [normalized difference vegetation index]) and spatial heterogeneity in topography and landscape patterns (composition and configuration) at multiple spatial scales. Stratified random sampling was used to collect data on butterfly species richness from seventy-six 20 × 50 m plots. The plant species richness and average vegetation height data were collected from 76 modified-Whittaker plots overlaid on 76 butterfly plots. Spatial heterogeneity around sample plots was quantified by measuring topographic variables and landscape metrics at eight spatial extents (radii of 300, 600 to 2,400 m). The number of butterfly species recorded was strongly positively correlated with plant species richness, proportion of shrubland and mean patch size of shrubland. Patterns in butterfly species richness were negatively correlated with other variables including mean patch size, average vegetation height, elevation, and range in NDVI. The best predictive model selected using Akaike’s Information Criterion corrected for small sample size (AIC_c), explained 62% of the variation in butterfly species richness at the 2,100 m spatial extent. Average vegetation height and mean patch size were among the best predictors of butterfly species richness. The models that included plot-level information and topographic variables explained relatively less variation in butterfly species richness, and were improved significantly after including landscape metrics. Our results suggest that spatial heterogeneity greatly influences patterns in butterfly species richness, and that it should be explicitly considered in conservation and management actions.     

Biodiversity and community structure of temperate butterfly species within a gradient of human disturbance: An analysis based on the concept of generalist vs. Specialist strategies

We monitored nine butterfly communities with varying degrees of human disturbance by conducting a census twice a month during 1980 by the line transect method in and around Tsukuba City, central Japan. We analyzed the biodiversity and community structures using the generalist/specialist concept. The site (community) order based on decreasing human disturbance was positively correlated with butterfly species diversity (H′), species richness (the total number of species), and the number of specialist species in a community, but not with the number of generalist species. The number of generalist species was rather constant, irrespective of the degree of human disturbance. Thus, both the butterfly species diversity and species richness were more dependent on the specialists than the generalists. Our analyses also showed that the generalist species were distributed widely over the communities, and they maintained high population densities, resulting in high rank status in abundance in a community, with more spatial variation in density per species. Specialist species showed the opposite trends. These results demonstrate that the generalist/specialist concept is a powerful tool applicable to analyse the biodiversity and structure of natural communities.     

Relationships between the age of northern Kantou plain (central Japan) coppice woods used for production of Japanese forest mushroom logs and butterfly assemblage structure

To discern mechanisms maintaining the diversity of grassland and forest butterflies in coppice woods managed for the production of Japanese forest mushroom logs, we investigated the butterfly fauna in cut-over land tracts shortly after felling and 5 year later, and in forest stands 10, 15, and 25 year after felling (here, we use the term “forests” when referring to the chronosequence of these treed stands). Butterfly species richness and diversity (H′) and the densities of individuals were highest in cut-over lands 5 year after clear-cutting, followed by 25-year-old forest stands. In forests, the richness and densities of forest butterfly species were higher than were those of grassland species. Among forest stands of different ages, forest butterfly species’ richness and the densities of individuals were highest in 25-year-old woods nearing felling time. Some forest butterfly species were observed only in forests. The species richness and densities of grassland butterflies were much higher in cut-over lands 0 and 5 year post felling than in forests; grassland species were rarely found in stands ≥10 year old. Thus, cut-over lands seem to function as temporary habitats for grassland species. Furthermore, the number of forest butterfly species was the same in cut-over lands 5 year after felling and in 25-year-old forest stands; the densities of forest butterfly species was higher in these cut-over lands than in the forest stands. Forest butterfly species living on cut-over land 5 year post felling sipped flower nectar, laid eggs on host plants, and practiced territorial behaviour involved in mate finding. Hence, these cut-over lands functioned as important habitats for various developmental stages of forest butterflies. In conclusion, traditional coppicing in woods for production of Japanese forest mushroom logs is very important for the maintenance of diversity in grassland and forest butterfly species.     

Ferns,frogs, lizards,birds and bats in forest fragments and shade cacao plantations in two contrasting landscapes in the Atlantic forest,Brazil

The traditional shade cacao plantations (cabrucas) of southern Bahia, Brazil, are biologically rich habitats, encompassing many forest-dwelling species. However, a critical question for the conservation management of this specific region, and the highly fragmented Atlantic forest in general, is to what extent the conservation value of cabrucas relies on the presence of primary forest habitat in the landscape. We investigated the relative importance of cabrucas and forests for the conservation of five diverse biological groups (ferns, frogs, lizards, birds and bats) in two contrasting landscapes in southern Bahia, one dominated by forest with some interspersed cabrucas, and one dominated by cabrucas with interspersed forest fragments. The community structure (richness, abundance and diversity) of all biological groups differed between cabrucas and forests, although these differences varied among groups. A high number of forest species was found in the cabrucas. However, there were pronounced differences between the two landscapes with regard to the ability of cabrucas to maintain species richness. Irrespective of the biological group considered, cabrucas located in the landscape with few and small forest fragments supported impoverished assemblages compared to cabrucas located in the landscape with high forest cover. This suggests that a greater extent of native forest in the landscape positively influences the species richness of cabrucas. In the landscape with few small forest fragments interspersed into extensive areas of shade cacao plantations, the beta diversity of birds was higher than in the more forested landscape, suggesting that forest specialist species that rarely ventured into cabrucas were randomly lost from the fragments. These results stress both the importance and the vulnerability of the small forest patches remaining in landscapes dominated by shade plantations. They also point to the need to preserve sufficient areas of primary habitat even in landscapes where land use practices are generally favorable to the conservation of biodiversity.     

Richness, Abundance, and Complementarity of Fruit-feeding Butterfly Species in Relict Sacred Forests and Forest Reserves of Ghana

Sacred forest groves in Ghana are centuries old protected areas that were once part of continuous forest cover but now mostly exist as relict forest patches embedded in an agropastoral landscape. We conducted a year-long survey of the fruit-feeding butterfly fauna of four sacred groves and two forest reserves in the moist semi-deciduous forest zone of Ghana to characterize resident species diversity and complementarity among communities. Joint analysis of frugivorous butterfly diversity at these six forest fragments, which ranged in size from 6 to 5000 ha, was used to evaluate the conservation potential of these ancient indigenous reserves. A total of 6836 individuals were trapped across all sites, representing 79 species and five subfamilies. Community diversity was characterized in terms of, (a) number of species accumulated versus sampling effort, (b) rarefied species richness, (c) nonparametric richness estimates, (d) species evenness, (e) Simpson’s Index of Diversity, and (f) complementarity of communities. Diversity of the fruit-feeding butterfly communities, quantified in terms of both species evenness and rarefied species richness, was higher at the larger forest reserves than at the small sacred forest groves. Additionally, although all sites had species trapped only at that site, the 5000-ha forest reserve harbored a resident community that was clearly distinctive from and more diverse than the other communities including the other forest reserve. Hence, our findings add to the burgeoning body of data that indicates large reserves are the foundation of successful conservation programs. Nonetheless, we found these small forest patches contribute to biodiversity conservation in at least three ways and these are identified and discussed. We also identify a number of species that appear more or less vulnerable to dynamics of forest fragmentation based on changes in their relative abundance across sites and we interpret these data in the context of potential indicator species and theoretical predictions of at-risk species.     

Springtails (Hexapoda,Collembola) of Tundra Landscapes of the Kola Peninsula

A quantitative study of collembolan assemblages on the Barents Sea coast of the Kola Peninsula was performed. Altogether, 104 collembolan species of 55 genera and 16 families were found. Analysis of the faunal composition revealed its high similarity to that of the faunas of the neighboring regions of Norway as well as a marked decline in species richness as compared to the Siberian analogues. A high share of littoral forms with increased vagility and the predominance of species with “southern” (= boreal) and “western” distribution patterns are the main characteristics of the fauna studied; only a few true arctic forms were found, always with low abundance and occurrence levels. Most of the studied collembolan assemblages are characterized by the dominance of a few species which inhabit a part of or the entire range of plant communities. As a result, collembolan assemblages under various types of vegetation cover in different landscape elements often show only insignificant differences.     

Can parasites be indicators of free-living diversity? Relationships between species richness and the abundance of larval trematodes and of local benthos and fishes

Measuring biodiversity is difficult. This has led to efforts to seek taxa whose species richness correlates with the species richness of other taxa. Such indicator taxa could then reduce the time and cost of assessing the biodiversity of the more extensive community. The search for species richness correlations has yielded mixed results, however. This may be primarily because of the lack of functional relationships between the taxa studied. Trematode parasites are highly promising bioindicators. Diverse assemblages of larval trematode parasites are easily sampled in intermediate host snails. Through their life cycles these parasites are functionally coupled with the surrounding free-living diversity of vertebrate and invertebrate animals. It has been shown that larval trematodes in snails correlate positively with bird diversity and abundance. Here, we explore whether trematodes also correlate with standard measures of fishes, and large and small benthos, for 32 sites in three wetlands. We found associations between trematodes and benthic communities that were not consistent across wetlands. The associations were, however, consistently positive for large benthic species richness and density. Some of the contrasting associations between trematode and benthos may be explained by negative associations between large and small benthos. We found no associations with fish communities (probably because of the inadequacy of standard “snapshot” sampling methods for highly mobile fishes). The results support further exploration of trematodes as bioindicators of diversity and abundance of animal communities. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Small scale gradient effects on isopods (Crustacea: Oniscidea) in karstic sinkholes

We studied abundance and diversity patterns of terrestrial isopod assemblages along a ‘micro-scale’ vertical gradient in sinkholes in the Aggtelek National Park, Hungary. Time restricted manual sampling yielded ten native species, including endemic and rare ones. Along the gradient we found no major differences in species richness and -composition, and abundance decreased from the bottoms to the upper zones of the sinkholes. Species specific habitat preference on a vertical gradient showed two distinct groups by indicator species analysis: occurrence of habitat “generalists” was irrespective of vertical zones while “specialists” were restricted to the bottoms of the dolines. The latter group is formed mainly by rare species. We found that both diversity and evenness of isopod assemblages were highest in the bottom zone. Our results draw the attention to the significance of such common, yet undiscovered surficial depressions that can provide shelters for rare and specialist species and can provide shelter for survival of populations under changing climatic conditions.     

Primary and secondary vegetation patches as contributors to floristic diversity in a tropical deciduous forest landscape

The floristic diversity of Mexican tropical deciduous forests (TDF) is of critical importance given the high species richness (alpha diversity), species turnover (beta diversity), and the intense deforestation rates. Currently, most TDF landscapes are mosaics of agricultural land, secondary vegetation, and patches of relatively undisturbed primary vegetation. Here we illustrate how both primary forest remnants and secondary vegetation patches contribute to the floristic diversity of TDF in a landscape of volcanic origin in central Veracruz, Mexico. Our objectives were to assess sampling efficiency and inventory completeness, to compare mean and cumulative species richness between primary forest and secondary vegetation sites, and to analyze beta diversity between vegetation types. In an area of 12,300 m2 we recorded 105 families, 390 genera, and 682 species. Species inventories for both vegetation types were about 80% complete. Secondary vegetation is more alpha diverse than primary forest, both in terms of cumulative and mean species richness. We found a remarkably high beta diversity between vegetation types (75% of complementarity, 91.60% of mean dissimilarity). We also identified the species that contribute the most to similarity within vegetation types and to dissimilarity between vegetation types. Our results support the idea that assessing biodiversity on the landscape scale is an appropriate way to ascertain the impact of human activities. For this land mosaic, conservation of the flora would not be possible by focusing solely on primary forest remnants. We propose the implementation of a network of small conservation areas with a flexible structure, following the “archipelago reserve” model.     

Regional hotspots of butterfly diversity in a protected area: Are they indicators of unique assemblages and areas with more species of conservation concern?

The implementation of biodiversity studies to set conservation priorities assumes that the different criteria used in prioritisation are correlated. Based on butterfly data, we examined whether high total diversity (species density and richness), unique species assemblages, and high numbers of different categories of Species of European Conservation Concern (SPEC) were co-located in the same habitats in the Picos de Europa National Park, Spain. Species density (number of species per sample) declined with elevation and was significantly higher in Genista shrublands on southern slopes (Southern Genista shrubland). We found unique species assemblages for Southern Genista shrublands, heathlands, mown meadows and subalpine meadows, whereas Genista shrubland on northern slopes (Northern Genista shrubland) and pastures were occupied by more habitat generalist species. We also found an effect of elevation on species composition. Species with global distributions concentrated in Europe (SPECs 4b) tended to be associated with Southern Genista shrubland, whereas species with global distributions restricted to Europe (SPECs 4a) were associated with higher elevations. Thus, we suggest a higher conservation value for butterfly assemblages located both on Southern Genista shrublands and at high elevations as they contain unique assemblages with a higher number of SPECs. By comparing our data with a previous study on carabid beetles, we found a low coincidence between butterflies and beetles for habitats with high species diversity and unique assemblages. Our study suggests that preserving areas in the landscape supporting higher butterfly diversity only partially preserves those species of greater conservation concern, and that butterflies cannot be used as a reliable indicator of other priority taxa for conservation, such as carabid beetles.     

Effects of Wildflower Strip Quality,Quantity, and Connectivity on Butterfly Diversity in a Swiss Arable Landscape

The effects of habitat restoration measures designated to promote farmland biodiversity have been documented at the field scale, but little is known about their role in restoring the agricultural mosaic. In this study, we analyzed the effects of wildflower strips (WFS) at the field scale and in the landscape context on butterflies in a Swiss arable landscape. Three hypotheses were tested: (1) butterfly diversity and abundance are higher in WFS than in conventional fields; (2) butterfly diversity and abundance are enhanced by the amount, proximity and connectivity of WFS in the landscape context; (3) additional factors influence butterfly diversity and abundance according to individual site conditions and landscape context characteristics linked to other landscape elements. WFS had more species and individuals of butterflies than conventional habitats. However, promoted species were mainly generalists; few specialists were enhanced. The diversity of all butterflies and of generalists increased linearly with percent cover of WFS, reflecting an effect of restoration measures depending on the landscape context. The influence of proximity and connectivity of WFS were, however, not significant. The occurrence of specialists was conditioned by plant species richness, while the effect of WFS for overall diversity was affected by the amount of grassland in the surroundings. We conclude that to increase the effectiveness of biodiversity‐orientated restoration measures, their implementation should be steered toward increasing the share of WFS in the landscape. However, the combination of WFS with additional restoration measures might be needed to halt the decline of specialist species.     

Importance of semi-natural habitats for the conservation of butterfly communities in landscapes dominated by pine plantations

While the area of plantation forests continues to increase worldwide, their contribution to the conservation of biodiversity is still controversial. There is a particular concern on the central role played by natural habitat remnants embedded within the plantation matrix in conserving species-rich insect communities. We surveyed butterflies in maritime pine plantation landscapes in south-western France in 83 plots belonging to seven habitat types (five successional stages of pine stands, native deciduous woodlands and herbaceous firebreaks). The effect of plot, habitat and landscape attributes on butterfly species richness, community composition and individual species were analysed with a General Linear Model (GLM), partial Canonical Correspondence Analysis (CCA) and the IndVal method. The most important factors determining butterfly diversity and community composition were the presence of semi-natural habitats (deciduous woodlands and firebreaks) at the landscape scale and the composition of understorey vegetation at the plot scale. Pure effects of plot variables explained the largest part of community variation (12.8%), but landscape factors explained an additional, independent part (6.7%). Firebreaks were characterized by a higher species richness and both firebreaks and deciduous woodlands harboured species not or rarely found in pine stands. Despite the forest-dominated landscape, typical forest butterflies were rare and mainly found in the deciduous woodlands. Threatened species, such as Coenonympha oedippus and Euphydryas aurinia, were found in pine stands and in firebreaks, but were more abundant in the latter. In the studied plantation forest, the conservation of butterflies depends mainly on the preservation of semi-natural habitats, an adequate understorey management and the maintenance of soil moisture levels.     

Bird assemblages in fragmented agricultural landscapes: the role of small brigalow remnants and adjoining land uses

Agricultural intensification typically leads to changes in bird diversity and community composition, with fewer species and foraging guilds present in more intensively managed parts of the landscape. In this study, we compare bird communities in small (2–32 ha) brigalow (Acacia harpophylla) remnants with those in adjacent uncultivated grassland, previously cultivated grassland and current cropland, to determine the contribution of different land uses to bird diversity in the agricultural landscape. Twenty remnant brigalow patches and adjacent agricultural (‘matrix’) areas in southern inland Queensland, Australia were sampled for bird composition and habitat characteristics. The richness, abundance and diversity of birds were all significantly higher in brigalow remnants than in the adjacent matrix of cropping and grassland. Within the matrix, species richness and diversity were higher in uncultivated grasslands than in current cultivation or previously cultivated grasslands. Forty-four percent of bird species were recorded only in brigalow remnants and 78% of species were recorded in brigalow and at least one other land management category. Despite high levels of landscape fragmentation and modification, small patches of remnant brigalow vegetation provide important habitat for a unique and diverse assemblage of native birds. The less intensively managed components of the agricultural matrix also support diverse bird assemblages and thus, may be important for local and regional biodiversity conservation.     

Ecoregional Vulnerability Assessment for the Functional Richness of South American Carnivorans (Mammalia: Carnivora)

Mapping geographic trends in biodiversity is a key step in conservation planning, which has been mainly focused on taxonomic criteria or species of particular concern. More recently, higher consideration of ecosystem functioning has been advocated, allocating more attention to traits and functional diversity of species assemblages. Carnivorans (Mammalia: Carnivora) are charismatic, albeit threatened, species that variously affect ecosystem functioning through consumptive processes, and whose functional diversity depends on traits associated with their trophic habits and energetic requirements. Yet, analyses of spatial trends in the diversity and vulnerability of carnivoran assemblages have mostly focused on taxonomic and phylogenetic criteria. Then, the present study assessed the vulnerability of the functional richness of South American carnivoran assemblages, both at continental and regional levels. As a first diagnostic of vulnerability, the form of the association between functional richness and species richness (FRS) was assessed through simulations. The resulting nearly linear association indicated low functional redundancy and high sensitivity to global extinctions. A more realistic FRS accounting for actual extinction threats exacerbated losses of functional richness. Further, a positive correlation between effect and response traits suggests non-compensatory responses to environmental stressors by functionally redundant species and, thus, sensitivity of carnivoran functional richness to ongoing trends in land conversion and habitat degradation. Regionally, functional richness paralleled latitudinal gradients in species richness, but vulnerability did not entirely match these variables in space, nor did it risk estimates that accounted for regions’ conservation status. This suggests regional differentiation in conservation priorities, complementing existing taxonomically oriented prioritization schemes.