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Abstract Over the last decades, numerous natural habitats have been converted into settlement areas, agricultural land, and tree plantations on a large spatial scale. As a result, natural ecosystems have been destroyed. In consequence, many ecosystems exist today as small and geographically isolated remnants. To what extent the original species diversity can persist in such small habitat patches is questionable and strongly depends on the ecology of the species. A prominent example of severe habitat destruction are the species-rich tropical cloud forests of Taita Hills in southern Kenya, which have been deforested almost completely during past decades. However, there still exist typical forest species in the few remaining forest fragments. In this study, we investigate the population ecology and behaviour of two butterfly species present in the cloud forest remnants of Taita Hills, Protogoniomorpha parhassus and Precis tugela. Over a period of one month, we conducted Mark-Release-Recapture to study population sizes and demographic structures, lifespan, dispersal, and behaviour. We found that both species exhibited medium population sizes and are sedentary. However, some individuals performed dispersal throughout the forest. The behaviour of the two species differs: While P. tugela was mostly observed basking with open wings, P. parhassus was mostly sitting under leaves with closed wings. The life span was rather long for butterflies. Implications for insect conservation This study documents the population ecology and behaviour of these two Afrotropical butterflies and underlines the relevance of the conservation of cloud forest remnants to preserve species, which mainly depends on these habitat remnants.

Context Intensification of land-use caused a reduction of ecosystem heterogeneity and diversity, and subsequently led to dramatic decrease of biodiversity. Species depending on dynamic ecosystems are particularly affected from this trend of land-use intensification, landscape homogenization, and the optimization of land-use. Forest species suffer under the intensification of forest management, in the worst case transforming light and heterogeneous deciduous forests into species-poor intensively used deciduous forests optimized for wood production. This lead to the destruction of a mosaic consisting of various successional stages in parallel. Objective In this study we analyse the relevance of forest heterogeneity, forest disturbance and microhabitat preferences of egg oviposition and larval development for a highly endangered butterfly species, Euphydryas maturna. This butterfly species mainly occurs in light and moist deciduous forests, such as riparian forests along mountain streams in northern Austria. Methods We combine detailed field observations with high resolution aerial pictures taken with an Unmanned Aerial Vehicle (UAV) to build ensemble habitat suitability models from GAM, GBM, GLM, and Maxent models. Results We found that egg ovipositions take place exclusively on the tree species Fraxinus excelsior, preferably exposed to the south, partly shaded, and at medium height (3 m). Our habitat suitability models based on high resolution aerial pictures indicate that egg ovipositions are clustered and accumulate along forest edges and at sites with high forest heterogeneity. Conclusion Our study underlines the high relevance and importance of light deciduous forest structures with environmental dynamics creating the preconditions of specific microhabitat structures for endangered species, such as E. maturna. Our study shows that UAV-captured high precision aerial imagery are well suited to optimally connect two spatial scales, the ecosystem and microhabitat scale.

Biodiversity is declining across the globe. Main drivers causing the vanishing of species are habitat destruction and the transformation of former heterogeneous landscapes into homogeneous and intensively used landscapes. Modern land management focuses on the creation of landscape configuration with sharp boundaries between ecosystems. In consequence, transition zones between two ecosystems such as between forest and open grassland are rare, as it counteracts the efficient and commercial use of space. However, there are many species relying on such transition zones between habitats, as the Clouded Apollo butterfly Parnassius mnemosyne. This highly endangered butterfly species occurs in light deciduous forests, interspersed with extensively used grasslands. In our study, we analysed habitat requirements of this butterfly species. We recorded larvae and feeding marks at its primary larval food plant, Corydalis cava, and assessed microhabitat characteristics, including microclimatic conditions. We captured high-resolution multispectral aerial imagery with an unmanned aerial vehicle. We subsequently combined ground-truthing data with information from high resolution aerial pictures to calculate habitat suitability models. We found that P. mnemosyne larvae mainly occur in the transition zone between deciduous light forest and extensively used grasslands with C. cava. Caterpillars of P. mnemosyne are particularly found around trees, basking on foliage and grass to rapidly reach high operation temperatures. Results from Species Distribution Models underline the relevance of transition zones between habitats for P. mnemosyne, and for biodiversity in general. The Clouded Apollo may serve as excellent indicator species for light deciduous forests, and as flagship to promote the conservation and restoration of transition zones between habitats in nature conservation.

Numerous conservation activities in Africa have been of little effect. In this study, we investigate socio-economic trade-offs that might have been overlooked, yet may undermine conservation action in discret pathways. Data was collected in three study sites with fragile forest ecosystems in south-eastern Kenya, through locally adapted structured surveys and semi-structured expert guides. These analyses are drawn from 827 structured surveys and 37 expert interviews, which were done during 2016–2018. We found general coherences between age, gender, ethnicity, indigenous knowledge, formal education, and higher incomes, which shapes forest conservation attitudes. Indigenous knowledge is marginal, and most people with formal education in the rural setting are likely to be young without legal land rights or among the minority with off-farm employment. The reluctance to address historical land injustices and inequitable sharing of entitlements and management authority overrides positive attitudes and intentions towards forest conservation in all three study sites. However, we found considerable discrepancies among the three study sites. For Arabuko Sokoke forest, the awareness of forest conservation was relatively low when compared with the other two study sites. Forests play a major role against the backdrop of resource use in all three regions. But, different ecosystem services are used among the three study sites. For environmental education and communication, internet plays a comparatively minor role. Strategies to preserve forest differ among the three study sites: Reforestation is proposed in cloud forests of Taita Hills and riparian forests, whereas off-farm employment and alternative income sources plays a major role in Arabuko Sokoke forest. Our findings underline that locally specific conservation management is needed to conduct efficient nature conservation, particularly in countries with very heterogeneous ethnicities and environments.

The cloud forests of the Taita Hills are valuable refuges for numerous endemic and rare animal and plant species. They also provide various ecosystem services that support subsistence farming. Due to the large-scale destruction and conversion of these species-rich natural forests into subsistence agriculture and plantations of exotic tree species, most of the natural cloud forest habitats have disappeared and ecosystem services have been significantly diminished. Despite numerous conservation initiatives, the destruction of the Taita Hills forest ecosystem continues, which also lowers livelihood quality of the local people. During a workshop with representatives of GOs, NGOs, researchers and representatives of the local community we identified potential factors which are essential to reverse this negative trend. We found that governance structures urgently need to be strengthened, and that the traditional conservation system needs to get transformed and revitalised. The basic prerequisite is a vital communication among generations, especially between the youth and the elders, as well as and improved communication of scientific knowledge to policy makers and the society. Furthermore, it is essential to harmonize stakeholders’ mandates, policies and actions to efficiently restore this unique forest biodiversity hotspot, and to secure livelihood needs for the local people.

Species community structures shape ecosystem functions, which are mostly stronger pronounced in intact than in degraded environments. Riparian forests in semiarid Africa provide important habitats for endangered plant and animal species and provide various ecosystem functions, that is, services to people settling along these streams. Most of these riparian forests are severely disturbed by human activities and dominated by invasive exotic plant species in the meanwhile. Thus, ecosystem functions are negatively influenced. While most studies have analyzed a specific metric to measure the degree of ecosystem function, little is known about how strongly different ecosystem functions respond to anthropogenic disturbances in parallel. In this study, we analyzed a set of four proxies of ecosystem functions, ground‐dwelling arthropod abundances, pollination, seed dispersal, and predation, along a highly disturbed riparian forest in southeastern Kenya. We assessed the land cover and land use manually and with an Unmanned Aerial Vehicle. Our data show that ecosystem functions respond differently to vegetation cover, human disturbances, and the availability of the invasive exotic shrub Lantana camara. The occurrence of representatives from the groups Saltatoria and Formicidae profits from heterogeneous habitat structures and natural riparian forest, while representatives of the Araneae profit from high proportion of agricultural fields. In general, predation is higher in mixed land use and natural riparian forest, while pollination and seed dispersal showed no significant trend in regard on land coverage. Along with this, predation also increased with rising proportion of natural riparian forest, while the proportion of agricultural land negatively affects predation, but in parallel showed a slightly significant positive trend with seed dispersal. Human disturbances and the occurrence of the invasive exotic L. camara shrub did not significantly affect our metrics of ecosystem functioning, except of the negative impact of human disturbances on pollinators. In conclusion, our results underpin that ecosystem functions respond highly variable and individually to environmental changes., Ecosystem functions are crucial for human well‐being. We analyzed four proxies to evaluate ecosystem functions in a degraded riparian forest in southeastern Kenya. Our data indicate that intense land use and the invasion of exotic plants negatively impact some of the ecosystem functions assessed.

Prioritization is crucial in nature conservation, as land and financial resources are limited. Selection procedures must follow objective criteria, and not primarily subjective aspects, such as charisma. In this study, we assessed the level of charisma for all European butterflies. Based on these data, we analysed the charisma values of the species listed on the annexes of the EU Habitats Directive and of the species being of conservation priority according to criteria derived by three objective criteria: Species ecological specialisation, distribution, and threat. The mean level of charisma was higher for species of the EU Habitats Directive than for species of conservation priority and for not-listed species. Five of the twenty most charismatic species were also listed on the EU Habitats Directive, but none occurred on the list of species being of conservation priority. A trait space analysis revealed remarkable differences between the different species assortments: The species listed on the EU Habitats Directive covered a large trait space and included many species with high charismatic value, but low ecological and biogeographical relevance, while species of high conservation priority covered a restricted trait space and did not overlap with charismatic species. According to our findings, the selection of species for nature conservation still follows a mix of being aesthetic combined with some ecological criteria.

Tropical forests suffer severe habitat destruction. Thus, tropical forests frequently consist today of only a few small remnants that are often embedded within a matrix of agricultural fields and tree plantations. Forest specialist species have experienced severe population declines under these circumstances. We studied bird communities based on census plots set up in a near-natural forest block, as well as degraded forest patches, tree plantations, and agricultural fields, across the Taita Hills in southern Kenya. We classified each bird species according its ecology and behavior. We quantified the land cover and landscape configuration around each census plot. Typical forest species were mainly observed in the near-natural forest block, and to a lower extent in degraded forest patches. Plantations were almost devoid of birds. Bird communities of small forest fragments were more similar to that of agricultural land than the near-natural forest block. Most frugivorous, insectivorous and nectarivorous birds occurred in forest habitats, while granivorous bird species dominated the bird communities of agricultural land. The surrounding landscape had a marginal impact on bird species composition at local sites. Our study showed that the preservation of near-natural cloud forest, including small forest patches, is essential for the conservation of forest-dependent species, and that plantations do not serve as surrogate habitats.

Context Biodiversity is severely decreasing at a global scale since several decades. There are significant changes in species community compositions, reductions of species richness and abundances of arthropods, as well as of arthropod biomass. Land use intensification and climate change are assumed to be main drivers causing biodiversity change and loss. However, proximate effects of land use, landscape configuration, topography and climate on species richness and species community composition were only rarely analysed. Objective We study the effects of current land cover, landscape structures and climate on butterfly and burnet moth species diversity and community composition across northern Austria (i.e. the federal state of Salzburg). Methods We compiled observation data of butterflies and burnet moths for the past 40 years. We divided faunal data, land cover data and data on climate into 5 × 5 km2 grid cells. We classified all lepidopterans assessed into groups according to their distribution, behaviour, ecology and life-history. Results We found higher species richness and temporal community shifts in higher elevations, and where topographic heterogeneity is high. Habitat connectivity has a positive impact on ecologically specialised, sedentary, and endangered species. Mean temperature and precipitation positively influenced species richness. Conclusions Both, land-use and climate strongly shape biodiversity structures. In particular, landscape heterogeneity promotes the diversity of ecological niches, which subsequently accelerates species diversity, including specialist species. Agricultural intensification in higher elevations and at steep slopes is more difficult and therefore less attractive, and thus the level of biodiversity is still high. In addition, climate warming might lead to the accumulation of species in higher elevations. Our study further underlines the relevance of habitat conservation at lower elevations, where not all habitat types are conserved sufficiently.

Genetic diversity is of crucial importance for population fitness and the potential of populations to adapt to environmental change. Population-level genetic diversity is expected to be reduced in specialists having small and isolated populations. We analysed genetic structure and diversity in (pre-)Alpine populations of four Copper butterfly species, differing in the degree of habitat specialisation. Despite substantial variation among genetic markers and molecular indices, genetic diversity and thus evolutionary potential tended to be highest in Lycaena hippothoe and lowest in L. tityrus. Microsatellite analyses revealed that genetic diversity tended to be higher in L. hippothoe and L. virgaureae than in L. helle and L. tityrus. MDH sequencing indicated only few differences among species, while GAPDH sequencing showed higher genetic diversity in L. hippothoe and L. tityrus than in L. virgaureae and L. helle. In L. helle, populations showed strong genetic differentiation but without clear spatial structure, while the other species showed genetic differentiation among clusters according to cardinal directions. These results do not match our a priori predictions of a high genetic diversity in L. tityrus and a particularly low one in the glacial relict L. helle. We thus document that evolutionary potential is not necessarily constrained in relict taxa, and that predicting genetic diversity is challenging. Conservation status does not necessarily reflect genetic diversity at the species level. It thus seems to be more meaningful to focus on specific populations of concern to assess genetic vulnerability to environmental change.

The success of nature conservation strongly depends on the attitudes and awareness of people, as well as on the level of poverty, land scarcity, communication gaps, and governance structures. In this commentary we elaborate potential effects of inter-community differences on peoples´ attitudes towards nature conservation and the role of land management, communication and governance in nature conservation for three forest regions in south-eastern Kenya. We considered the following areas: the riparian forests in the semi-arid Kitui county, the Arabuko Sokoke coastal forest, and the cloud forests of the Taita Hills. In all three areas, the remaining forests are strongly fragmented and forest habitat quality is degraded, yet still supports outstanding diversity of plant and animal species richness. Despite current efforts to conserve these ecosystems, its degradation continues due to various reasons: (1) Population and economic pressure; (2) Limited land availability and insecure land tenure systems; (3) Inconsistencies between the legislation and governance; and, (4) Communication gaps and a lack of information flow among stakeholders from the national to the local level. Here we identify and present common and diverging coherences among the three study regions. We found that people´s awareness and willingness play a rather marginal role to turn nature conservation into successful management, but shortcomings in policies and governance are the main drivers.

The theory of island biogeography predicts that species diversity is lower on small islands and on islands far distant from the mainland, and higher on large islands with high habitat heterogeneity, and on islands close to the mainland. In addition, population and species persistence (i.e. their long-term survival) depends on life-history traits, including morphological, ecological and behavioural characteristics. These theories can also be used as basic hypotheses to test species persistence and community assembly of fragmented habitats. Lepidopteran communities living on small and isolated habitats, like small islands located along the northern German coast-line, provide an excellent model system to test for potential effects of species traits on their persistence and on the community assembly on islands and the mainland. Lepidopterans were assessed on the island Hallig Grode and on the adjoining mainland over a period of almost 50 years. About 500 species were recorded and classified according to their morphological, ecological and behavioural characteristics. Our data suggest less changes in the lepidopteran community composition on the island compared with the mainland. Yet, the number of species was considerably lower on the island compared with the mainland. The lepidopteran species community on the island was dominated by generalist species associated with meadows and grasslands. In contrast, lepidopteran species found at the mainland were frequently associated with forest and shrubs, and frequently showed a higher level of ecological specialization. Lepidopteran species caught on the island were equipped with more elongated wings compared with species found at the mainland. Our data suggest that the island situation functions as ecological filter allowing only specific species to persist and thus creates a subset of the mainland species community. Extrapolating our findings to isolated habitat patches across fragmented landscapes, we expect a similar filtering effect for species composition, and the long-term extinction of sedentary specialist species.

A main driver of biodiversity loss is the transformation of pristine habitats into agricultural land, plantations of exotic trees, and settlements. The cloud forest of the Taita Hills in southern Kenya has suffered under such transformation processes. In consequence, remaining forests are small and isolated and often provide degraded forest habitats. We studied butterfly communities in four habitat types, cloud forest, cloud forest margin, exotic tree plantations, and agricultural land. We counted butterflies along transects during the rainy and the dry season. We assessed species traits for each butterfly species found. The four habitat types harbour distinct butterfly communities with only slight overlap among each other. Community compositions differed between the dry and rainy season. Forest specialist butterflies mainly occurred in the interior of the cloud forest, but were also observable along the forest edge. Species richness was highest at the transition between pristine cloud forest and agricultural land. The butterfly community of open agricultural landscapes was dominated by common and widespread East African savannah species, equipped with more elongated wings compared with those found inside the cloud forest. Exotic tree plantations showed a mixed butterfly species composition, consisting of many common and widespread savannah species, but also forest species with comparatively low specialization. In conclusion, typical cloud forest butterflies are on the need for intact cloud forest patches and cannot be compensated by surrogate habitats, such as exotic tree plantations.

The number of insect species and insect abundances decreased severely during the past decades over major parts of Central Europe. Previous studies documented declines of species richness, abundances, shifts in species composition, and decreasing biomass of flying insects. In this study, we present a standardized approach to quantitatively and qualitatively assess insect diversity, biomass, and the abundance of taxa, in parallel. We applied two methods: Malaise traps, and automated and active light trapping. Sampling was conducted from April to October 2018 in southern Germany, at four sites representing conventional and organic farming. Bulk samples obtained from Malaise traps were further analyzed using DNA metabarcoding. Larger moths (Macroheterocera) collected with light trapping were further classified according to their degree of endangerment. Our methods provide valuable quantitative and qualitative data. Our results indicate more biomass and higher species richness, as well as twice the number of Red List lepidopterans in organic farmland than in conventional farmland. This combination of sampling methods with subsequent DNA metabarcoding and assignments of individuals according depending on ecological characteristics and the degree of endangerment allows to evaluate the status of landscapes and represents a suitable setup for large‐scale long‐term insect monitoring across Central Europe, and elsewhere., Malaise trap on the grassland of organic farmland.

Participatory forest management (PFM) is a major approach towards the reconciliation of biodiversity conservation and human livelihood needs. PFM was implemented around the Arabuko-Sokoke Forest (ASF), the largest remaining forest block of the East African coastal forest of southern Kenya, during the early 1990s. While forest cover has remained stable, there is evidence for persistent selective logging with subsequent reduction of habitat quality and a steady decline in biodiversity. We conducted structured surveys and semi-structured expert interviews to investigate the efficiency and acceptance of PFM by the local community. Hereby we considered two ethnic groups: The Waatha, the first known occupiers of the ASF, and the Giriama, recent settlers. We assessed the level of local awareness based on indigenous and modern ecological knowledge, peoples´ attitudes towards forest conservation, and their willingness to apply good environmental practices. Our quantitative analysis revealed low awareness of the uniqueness of biodiversity in ASF. Male respondents and those with higher formal education or indigenous knowledge, and long-term residents show significantly higher awareness. Majority (80%) of participants perceive the forest as being of high socioeconomic relevance and is a very important ecosystem service provider. However, less than half of the respondents express personal responsibility towards the conservation of this forest. The Waatha people show significantly higher scores on traditional ecological knowledge, willingness and personal responsibility towards forest conservation than the recent settlers, the Giriama. This study underlines that successful PFM depends on inter-ethnic relations and the history of the local people living in the ecosystem.

Prioritizing species for nature conservation should follow objective ecologically and biogeographically meaningful selection criteria. In this study, we test an approach to prioritize butterfly species for nature conservation considering the following parameters: (1) geographical distribution and endemicity, (2) vulnerability and (3) ecological specialization. Following these criteria, we identified 51 species of conservation priority out of the 403 European species assessed, that is 12.7%. This list of species and those included in the annexes II and IV of the Habitats Directive (92/43/EEC) had only four species in common. The species selected by both approaches differed significantly in their traits considering their distribution and ecological specialization with the annexes of the EU Habitats Directive including many species that are neither range‐restricted nor have their core distribution within Europe, and furthermore many not threatened ecological generalists. Our results suggest that species prioritization for nature conservation should follow objective criteria, such as distribution and ecological specialization.

Severe decline in terrestrial insect species richness, abundance, flying biomass, and local extinctions across Europe are cause for alarm. Here, we summarize this decline, and identify species affected most. We then focus on the species that might respond best to mitigation measures relative to their traits. We review apparent drivers of decline, and critically reflect on strengths and weaknesses of existing studies, while emphasising their general significance. Generality of recent scientific findings on insect decline have shortcomings, as results have been based on irregular time series of insect inventories, and have been carried out on restricted species sets, or have been undertaken only in a particular geographical area. Agricultural intensification is the main driver of recent terrestrial insect decline, through habitat loss, reduced functional connectivity, overly intense management, nitrogen influx, and use of other fertilisers, as well as application of harmful pesticides. However, there are also supplementary and adversely synergistic factors especially climate change, increasingly intense urbanisation, and associated increase in traffic volume, artificial lighting and environmental pollution. Despite these various synergistic impacts, there are mitigating factors that can be implemented to stem the precipitous insect decline. Science can provide the fundamental information on potential synergistic and antagonistic mechanisms of multiple drivers of insect decline, while implementation research can help develop alternative approaches to agriculture and forestry to mitigate impacts on insects. We argue for more nature-friendly land-use practices to re-establish Europe’s insect diversity.

Species demanding specific habitat requirements suffer, particularly under environmental changes. The smallest owl of Africa, the Sokoke Scops Owl (Otus ireneae), occurs exclusively in East African coastal forests. To understand the movement behaviour and habitat demands of O. ireneae, we combined data from radio-tracking and remote sensing to calculate Species Distribution Models across the Arabuko Sokoke forest in southern Kenya. Based on these data, we estimated the local population size and projected the distribution of current suitable habitats. We found that the species occurs only in Cynometra woodland with large old trees and dense vegetation. Based on home range sizes and the distribution of suitable forest habitats, the local population size was estimated at O. ireneae, and of other specialist forest species, even further. Due to their close connection with intact Cynometra forest, O. ireneae is an excellent indicator of intact forest remnants. In addition, this species is a suitable flagship for the promotion and conservation of the last remaining coastal forests of East Africa.

Human livelihood needs and nature conservation often contradict. Yet, healthy ecosystems are crucial for human livelihood quality. The semi-arid regions of East Africa suffer under demographic pressure and soil depletion. Ecosystem degradation becomes particularly visible along rivers in semiarid regions of south-east Kenya, where former pristine riparian forests have been transformed into agricultural fields and settlements with negative effects on ecosystem services. In this study, we aim to understand how local smallholders perceive the challenges for the riparian ecosystems and what factors affect their engagement in environmental conservation. We surveyed about 200 farmers and performed expert interviews with representatives from governmental institutions from the field of land- and resource management along Nzeeu River in south-east Kenya. We assessed the level of education, land use practices, environmental knowledge, attitudes and the willingness to contribute to nature conservation. We tested for spatial bias to understand smallholders’ perceptions on environmental challenges. Our data show that land division due to inheritance is not perceived as a problem by the farmers. However, owners holding

Biodiversity is declining, with major causes identified as habitat loss and a reduction of habitat quality. Recent studies have shown that particularly species with specific habitat demands are suffering in this way. Accordingly, habitat specialists have been nominated as umbrella species, which because they represent a much larger number of species, are thought best to fulfil the requirements of nature conservation. However, species which are ecologically intermediate between habitat specialists and generalists, and typically form networks of populations on adjoining habitats, might suffer even more severely under rapid habitat fragmentation than those specialists which had for a long time already occurred as discrete populations. Today, most of these formerly more widely distributed intermediate species also exist only as small and isolated populations which, because of their increasing geographic isolation, cannot counterbalance local extinctions by recolonisation. Furthermore, these species are mostly equipped with relatively high genetic diversity that is maintained by continual exchange of individuals between local populations. However, this high level of genetic variability frequently decreases after the collapse of population networks – with negative effects on the viability of these species. Thus, factors at the population and molecular levels may lead that formerly common species vanish in the near future.

Pristine tropical ecosystems are currently suffering under extreme demographic pressure. This has led to habitat destruction and disturbances, an important precondition for the invasion of exotic species into pristine ecosystems, with detrimental effects on biodiversity. In this study, we analysed the chronology of land cover changes along rivers in south-eastern Kenya using historical aerial photographs and current aerial pictures taken from a drone. We assessed quantity and quality of riparian thickets along these rivers in 1961, 1980 and 2015/2016 and analysed effects of fundamental land cover changes on arthropod abundance and diversity. Our data show effects from demographic pressure by the increasing number of human settlements rising by 425% from 1961 to 2015/2016 (i.e. from 36 to 189 settlements). 58.5% of the land surface originally covered by pristine riparian forests was cleared and transformed into agricultural land. After clearance and agricultural usage it frequently became fallow land and was invaded by the exotic shrub species Lantana camara. While the total coverage of riparian vegetation did not change over time, its quality declined dramatically. Currently 36.6% of the cleared pristine riparian forest is covered by L. camara thickets, and only 22.5% of the pristine riparian forest has remained unchanged over time. This modification of the vegetation structure impacts biodiversity. The abundances of three guilds of arthropods significantly differed between pristine and L. camara-dominated riparian vegetation, with herbivorous arthropods and ants being more abundant in pristine than in L. camara-dominated vegetation. Our data show that habitat destruction and disturbance is the prerequisite for subsequent invasion by exotic plant species, having a strong effect on species composition and diversity at higher trophic levels.

The Arabuko Sokoke dryland coastal forest along the East African coastline provides a unique habitat for many endangered endemic animal and plant species. High demographic pressure with subsequent land-splitting, soil depletion in combination with erratic rainfalls and the collapse of the tourism industry are negatively affecting food security and human livelihood quality in this region. Food crops were originally produced by subsistence farming, but have now to be purchased at local- and super-markets, constituting a major financial burden for the local people. In consequence, overexploitation of natural resources from Arabuko Sokoke forest (illegal logging, charcoal burning, poaching of wild animals) increased during the past years. In this commentary we document ecosystem heterogeneity leading to high species richness. We discuss direct and indirect drivers of habitat degradation of the Arabuko Sokoke forest, and critically reflect current and future solutions. Key drivers of habitat destruction and biodiversity loss are (i) illegal timber logging and removal of woody biomass, (ii) poaching of bush-meat, (iii) exceeding of the carrying capacity by the local elephant population, restricted to Arabuko Sokoke by an electric fence, and (iv) weak governance structures and institutional confusion exacerbating illegal exploitation of natural resources. Potential solutions might be: Provisioning of additional income sources; reforestation of the surrounding areas in the framework of REDD+ activities to create a buffer around the remaining primary forest; improving governance structures that formulates clear guidelines on future usage and protection of natural resources within the Arabuko Sokoke forest; and family planning to counteract human demographic pressure and the exploitation of natural resources.

Here we build on the manifesto ‘World Scientists’ Warning to Humanity, issued by the Alliance of World Scientists. As a group of conservation biologists deeply concerned about the decline of insect populations, we here review what we know about the drivers of insect extinctions, their consequences, and how extinctions can negatively impact humanity. We are causing insect extinctions by driving habitat loss, degradation, and fragmentation, use of polluting and harmful substances, the spread of invasive species, global climate change, direct overexploitation, and co-extinction of species dependent on other species. With insect extinctions, we lose much more than species. We lose abundance and biomass of insects, diversity across space and time with consequent homogenization, large parts of the tree of life, unique ecological functions and traits, and fundamental parts of extensive networks of biotic interactions. Such losses lead to the decline of key ecosystem services on which humanity depends. From pollination and decomposition, to being resources for new medicines, habitat quality indication and many others, insects provide essential and irreplaceable services. We appeal for urgent action to close key knowledge gaps and curb insect extinctions. An investment in research programs that generate local, regional and global strategies that counter this trend is essential. Solutions are available and implementable, but urgent action is needed now to match our intentions.

The fate of humans and insects intertwine, especially through the medium of plants. Global environmental change, including land transformation and contamination, is causing concerning insect diversity loss, articulated in the companion review Scientists' warning to humanity on insect extinctions. Yet, despite a sound philosophical foundation, recognized ethical values, and scientific evidence, globally we are performing poorly at instigating effective insect conservation. As insects are a major component of the tapestry of life, insect conservation would do well to integrate better with overall biodiversity conservation and climate change mitigation. This also involves popularizing insects, especially through use of iconic species, through more media coverage, and more inclusive education. Insect conservationists need to liaise better with decision makers, stakeholders, and land managers, especially at the conceptually familiar scale of the landscape. Enough evidence is now available, and synthesized here, which illustrates that multiple strategies work at local levels towards saving insects. We now need to expand these locally-crafted strategies globally. Tangible actions include ensuring maintenance of biotic complexity, especially through improving temporal and spatial heterogeneity, functional connectivity, and metapopulation dynamics, while maintaining unique habitats, across landscape mosaics, as well as instigating better communication. Key is to have more expansive sustainable agriculture and forestry, improved regulation and prevention of environmental risks, and greater recognition of protected areas alongside agro-ecology in novel landscapes. Future-proofing insect diversity is now critical, with the benefits far reaching, including continued provision of valuable ecosystem services and the conservation of a rich and impressive component of Earth's biodiversity.

Most studies on tropical conservation questions are conducted by researchers of developed countries from the north. This geographic disconnection was recently criticised by Mammides et al. Here, we reflect on their findings and add further views from scientist’s and journal editor’s perspectives. We argue that journals are, a priori, most strongly interested in research questions and approaches that will likely increase their scientific impact and prestige. This is rarely compatible with publishing articles on questions with restricted global impact or based on single taxa. We question whether small changes in the editorial policy of international conservation journals will considerably improve the geographic diversity in key conservation publications. Rather, thematic scopes of the leading conservation journals should be modified, preferably in close collaboration with leading conservationists from the south. We are convinced that long-term investments in the tropics will create a stronger local scientific community, thus bolstering academic morale, and finally may lead to an increase in the submission and acceptance rate of articles written from scientists from these regions.

Currently, there is an increasing need for evidence-based strategies in nature conservation, for example when designing and establishing nature reserves. In this contribution, we critically assess the ecological relevance of recent nature conservation practices in Kenya (East Africa), a region of global biodiversity hotspots. More specifically, we overlay the distribution of species richness (here based on mammals, birds, amphibians and vascular plants) with the location of nature reserves, the Kenyan agro-ecological zones (areas representing diverging agricultural potentials), and with the spatial distribution of human population density. Our analyses indicate that the majority of protected areas are located in areas with comparatively low species richness, while areas with extraordinary high levels of species richness are not adequately covered by nature reserves. Areas of high agricultural productivity (and with high human demographic pressure) are mainly reserved for high-yield agriculture; however, these regions are also characterised by high species richness. The majority of nature reserves are restricted to the semi-arid regions of Kenya, marginal for agricultural usage, but also with low levels of species richness. Based on this analysis, we prioritize areas for future protection. This single-country case illustrates that agricultural production in high-yield areas outweighs nature conservation goals, even in global biodiversity hotspot regions, and that priority setting may conflict with effective nature conservation.

Environmental changes strongly impact the distribution of species and subsequently the composition of species assemblages. Although most community ecology studies represent temporal snap shots, long-term observations are rather rare. However, only such time series allow the identification of species composition shifts over several decades or even centuries. We analyzed changes in the species composition of a southeastern German butterfly and burnet moth community over nearly 2 centuries (1840-2013). We classified all species observed over this period according to their ecological tolerance, thereby assessing their degree of habitat specialisation. This classification was based on traits of the butterfly and burnet moth species and on their larval host plants. We collected data on temperature and precipitation for our study area over the same period. The number of species declined substantially from 1840 (117 species) to 2013 (71 species). The proportion of habitat specialists decreased, and most of these are currently endangered. In contrast, the proportion of habitat generalists increased. Species with restricted dispersal behavior and species in need of areas poor in soil nutrients had severe losses. Furthermore, our data indicated a decrease in species composition similarity between different decades over time. These data on species composition changes and the general trends of modifications may reflect effects from climate change and atmospheric nitrogen loads, as indicated by the ecological characteristics of host plant species and local changes in habitat configuration with increasing fragmentation. Our observation of major declines over time of currently threatened and protected species shows the importance of efficient conservation strategies.

Conflicts between human needs and nature conservation are exceptionally pronounced along rivers in tropical Kenya, where riparian ecosystems create important retreats for many endangered species, but also provide important ecosystem services for the local human population. This situation has led to a landscape mosaic consisting of dense thickets and agricultural plots. We assessed the occurrence of the Kenyan endemic riparian bird species HindesBabbler Turdoides hindei along three rivers in south-east Kenya. We analysed the landscape coverage within habitat circles of 220 m radius, which are occupied and unoccupied (the latter randomly selected along the rivers) by our targeted bird species. Based on these data we calculated habitat preferences and population structure of T. hindei. Our data reveal that its occurrence probability increased with cov- erage of thickets. Furthermore, geographic distances among local populations of T. hindei decreased with thicket coverage and vice versa. These data reveal the relevance of thicket coverage as a key factor for the occurrence of T. hindei, influencing its population structure. However, most of the thicket patches mapped along the three rivers are small and geographically isolated from each other. Further deforestation might lead to additional reduction of the population size and abundance of T. hindei, and may ultimately lead to local extinction of this, and other endangered species adapted on riparian thickets. This

Anthropogenic activities caused a severe loss of pristine habitats alongside with fragmentation of remaining habitats and the deterioration of habitat quality. The Arabuko Sokoke forest represents the largest remnant of East African coastal forest. Despite conservation efforts to maintain biodiversity in this forest, populations of several species are declining, including flagship species like the endemic Sokoke Scops Owl Otus ireneae. In this study, we assessed the presence of O. ireneae based on playback technique to identify the occurrence of this species across the forest. We then analysed habitat parameters at sites occupied and non-occupied by the owl species. Our data show that O. ireneae occurs restricted to one single forest type, the Cynometra woodland. Results obtained from parametric one-way ANOVA and structural equation modelling reveal that large old Cynometra webberi trees and dead wood are key requirements for the occurrence of this owl species. However, large C. webberi trees are currently illegally logged by the forest adjacent human population to produce timber, carvings, poles. Charcoal and dead wood represents a major energy source for households. Otus ireneae, being the smallest owl of East Africa may serve as a charismatic flag ship species to promote conservation of this endangered coastal forest, and furthermore as umbrella to conserve other forest species with similar habitat requirements.

Research collaboration between developed countries from the northern hemisphere and developing countries in the southern hemisphere is essential for the understanding and protection of the major proportion of biodiversity located in the tropics. Focusing on the case of sub-Saharan Africa, we here assess the real involvement of northern versus southern contributors, and caution against unequal academic benefit sharing arising from non-commercial biodiversity research that may ultimately hamper sustainable knowledge transfer and long-term biodiversity conservation. We discuss possible drivers that may have led to a business of raw biodiversity data. While we fully support the current efforts to stamp out biopiracy through international biodiversity policies and agreements, we illustrate that such legislative frameworks may further constrain biodiversity research, especially in countries where regulations are poorly streamlined and bureaucracy remains rather inert. We therefore ask for workable solutions towards more equal footing in north-south biodiversity research, and propose a number of steps to transgress the current barriers towards a more fair and equitable sharing of benefits arising from biodiversity research.

Conservation science and conservation action are assumed to have identical goals. However, in reality, there is a strong divide between research and practical conservation that has been mostly discussed with respect to the ‘knowing-doing gap’, i.e. the results from science are not being translated into practical management. In this commentary, we argue that there is not one but there are at least three different types of gaps impeding a positive impact of science on conservation: (1) the knowing-doing gap; (2) the thematic gap that exists between the topics addressed by conservation science and the problems faced in conservation; and (3) the disciplinary gap, i.e. the lack of communication and cooperation between different fields of science, e.g. between fundamental biodiversity research and conservation research. These different gaps have different origins and require different means to be overcome. In a survey, scientists from the field of conservation research (all contributing to this special issue on European grasslands) assessed the importance of these three gaps. They highlight that the disciplinary gap is just as relevant as the knowing-doing gap, while the importance of the thematic gap between practical conservation needs and theoretical conservation science is, in the view of the authors, of less importance. Also, the respondents identified the complexity of academic content in scientific publications as an additional cause for knowing-doing gaps. Based on our survey and various other studies analysing these gaps, we suggest two ways to overcome the gaps: if you consider yourself to be a conservation scientist make sure to address questions of relevance for conservation issues, if you are a scientist interested in fundamental issues, be open to mutual interaction and translation of scientific results with conservation scientists. The knowing-doing gap could be addressed by more readily translating the theoretical findings into practical advice. “Conservation Journals” could, for instance, require a second “Conservation Management Abstract”, which has to be published open-access, and back-to-back with the conventional abstract.

Biodiversity is not homogenously distributed over the globe, and ecosystems differ strongly in the number of species they provide. With this special issue we highlight the ecology and endangerment of one of the most diverse ecosystem of Europe: the European grassland ecosystems. The selected 16 contributions describe interactions from below-ground to the atmosphere and focus on (1) effects of abiotic and biotic on species diversity, (2) the impact of various factors along spatial and temporal gradients, (3) the relevance of falling abandoned and eutrophication—including countervailing management strategies like encroachment; and (4) intraspecific effects based on physiology, genetics and intraspecific plasticity. The contributions cover fungi, plants, and invertebrates and highlight effects taking place at the level of ecosystem, species community, species, populations, and also within individuals (physiology and genetics).

The level of genetic diversity found for species is strongly influenced by properties of the species' ecology, abundance and behaviour (as dispersal). To address this coherence, we selected twenty-two grassland butterfly and burnet moth species, which were previously analysed by allozyme electrophoresis (using 15-25 loci per species) over a study area in western Germany with adjoining areas of Luxembourg and north-eastern France. For this study area, we calculated the species' specific climatic niche breadths and derived various ecological parameters from literature and own field observations. The obtained parameters of genetic diversity (heterozygosity, number of alleles and percentage of polymorphic loci), genetic differentiation (Dest as well as FST and FIS values as proxis for genetic differentiation among populations and inbreeding within populations), as well as ecological and climatic niche dimensions did not show significant differences among the different Lepidoptera families; therefore taxonomic assignment apparently has a negligible influence on the genetic structure of taxa. Genetic diversity and differentiation showed a significant correlation with the ecological and climatic niche-breadth of species in many cases: generalistic species with rather unspecific ecological characteristics and climatic niche had higher genetic diversities and tend to have lower differentiation and inbreeding, whereas specialist taxa (i.e. with narrow ecological and climatic niches) have lower genetic

Habitats often show similar present structuring, but contrasting histories: habitats occur naturally fragmented due to abiotic or biotic factors over long time periods, but may also have become fragmented only recently through transformation from interconnected to highly fragmented habitats within short time periods. Species and populations being faced with such contrasting habitat scenarios also show contrasting responses at species and intraspecific level. Organisms and populations from naturally fragmented habitats may show a reduction in their genetic load (purging) due to purifying selection in isolation. In contrast, sudden habitat transformations from interconnected to highly fragmented structures and the resulting transition from gene flow or panmixia to strong population differentiation often have negative effects on biota; while species occur in interconnected population networks (maintaining a high proportion of genetic diversity), a sudden breakdown of gene flow may lead to a severe loss of genetic diversity and the manifestation of weakly deleterious alleles. In consequence, fragmented habitats need not have a negative impact on species per se, but the history of habitat structures, particularly fast transformation processes, may severely affect the persistence and fitness of species.

In general, species with large ecological amplitudes are equipped with high genetic diversities. In contrast, more specialised species with narrow ecological amplitudes show low levels of genetic diversity. Generalist species are mostly rather marginally affected by recent land-use changes; specialist can be supported by specific conservation measures. We argue that, in the light of Conservation Genetics, species being ecologically intermediate between these two extremes are the most seriously affected ones by recent environmental changes. Such species which formerly occurred in large population networks have to sustain their high level of genetic variability via gene flow. Today, species from the latter group are negatively affected by rapid habitat collapses causing sudden lacks of population interconnectivity. Therefore, species with intermediate habitat demands and originally high genetic diversity might be at highest risk due to inbreeding depressions.

Isolated populations represent one of the main focuses in conservation biology. Long-term isolation often causes losses of genetic diversity and as a consequence might reduce individual fitness. Morphometric characters can be used as suitable markers to analyse ecological stress and individual fitness of local populations. Asymmetry in bilateral symmetry is used as a measure for developmental instability of populations and is often negatively correlated with population size and low genetic diversity. As a study system, we selected the endangered butterfly Parnassius apollo, which occurs in small and isolated remnant populations in Central Europe, but also in fairly large metapopulations in the Alps. We analysed wing morphometrics (shape and size characters) of 812 individuals representing (1) already extinct, (2) highly isolated and (3) still interconnected populations. Seventeen landmarks on veins were used to analyse morphological variances in the wing shape. Our data show significant deviations between landmarks on the left and right wing side within individuals and strong morphological variance among individuals. The highest morphological variability could be found for individuals in the Alps, however, the level of asymmetry was very similar for all populations analysed. The higher morphological variability found in the Alps can be interpreted as a consequence of the higher level of the genetic diversity detectable for this region. Analysis on morphological variance of P. apollo individuals of the Mosel valley using time series ranging from 1895 until today showed no significant rise in asymmetry and no decline of morphological variability over time, although, anthropogenic habitat destruction has caused severe bottlenecks in this population.

Agricultural intensification caused a fragmentation of flower-rich extensively used meadows which resulted in the reduction of the abundance of species of these habitats. The abundance pattern and the dispersal behaviour of species influence the connectivity of local populations. In this context exchange rates can be directly measured by mark release recapture (MRR) studies and indirectly by genetic analysis. Both approaches are used in our study in a comparative way. As a test species to investigate the influence of habitat interconnectivity on a local and regional scale, we selected the butterfly Melanargia galathea (Lepidoptera, Nymphalidae), a widely distributed species, which is common on flower-rich meadows in our study area in western Germany. We marked 3,175 individuals of four neighbouring sites in a mark-release-recapture study and analysed 18 allozyme loci for 644 individuals sampled over 17 sites. Only 3.3% of the total genetic variance was found among samples, thus supporting the detected between-patch movements. Both approaches revealed a high exchange rate among local populations. Moderate between- and high within-patch movements were recorded by MRR analysis, dependent on the geographical distance. The two analytical tools showed high estimated effective population sizes for all populations. In the light of conservation biology, the combination of the MRR and allozyme data support the assumption that high dispersal ability and habitat interconnectivity countervail genetic differentiation and enable the maintenance of a high level of genetic differentiation.

Many studies aim at testing the impact of recent fragmentation on the genetic diversity and connectivity of populations, while some species do exist naturally in fragmented landscapes because of their habitat requirements. Therefore, it is important to look at the genetic signatures of species occurring in naturally fragmented landscapes in order to disentangle the effect of fragmentation from the effect of habitat requirements. We selected two Nymphalid butterflies for this purpose. While Melanargia galathea is a common butterfly in flower-rich meadows, Melitaea aurelia is closely connected to calcareous grasslands, thus being historically fragmented due to its ecological demands. For the analysis of the genetic response on these opposed patterns, we analysed 18 allozyme loci for 789 individuals (399 individuals of M. galathea and 390 individuals of M. aurelia) in a western German study region with adjacent areas in Luxemburg and northeastern France. Both species showed similarly low genetic differentiations among local populations (M. galathea: F ST 3.3%; M. aurelia: F ST 3.6%), both combined with a moderate level of inbreeding. Isolation-by-distance analysis revealed a significant correlation for both species with similar amounts of explained variances (M. galathea: r 2 = 27.8%; M. aurelia: r 2 = 28.5%). Most parameters of genetic diversity were higher in M. galathea than in M. aurelia, but the latter species had a considerably higher amount of rare or locally restricted genes; the differing ecological demands are thus reflected in these differences. Both species thus seem to be genetically well suited to their respective ecological requirements. In the light of conservation genetics, we deduce that highly fragmented populations are not necessarily prone to extinction. The extinction risk might be linked to the life history of an organism and its population genetic structure.

The habitats of many species are fragmented. Therefore, the survival in a metapopulation depends on the stability of the single populations and the amount of movements between patches. We chose the calcareous grassland specialist butterfly species Polyommatus coridon as a model. As study area, we selected a mosaic-like landscape in Rhineland-Palatinate (western Germany) with several well preserved calcareous grassland fragments. We marked a total of 2,211 individuals during July and August 2003. The overall recapture ratio was 7.1%. The estimated mean butterfly densities over the whole flight season ranged from 52 to 487 individuals per hectare. The within-patch movements were relatively low (13.3%) compared with the between-patch movements (3.2%). Therefore, the metapopulation structure appears to be intact in our study area.

The recent controversial debate on land-sharing versus land-sparing is clearly exemplified in the East African mountains, one of the most diverse biodiversity hotspots on our planet. In these areas, species richness is particularly concentrated in the mountain cloud forests which are surrounded by a sea of dry lowland savannas heavily encroached on by local communities. Sustainable land use practices in the lowlands, however, are necessary to safeguard the natural capital at higher elevations. The interdependence between sustainable land-use and conservation of biodiversity hotspots was underlined during a workshop held in the rural areas of Kenya, East Africa, early spring 2013. It was concluded that close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa’s forest conservation efforts.

Feeding the booming human population and at the same time conserving biodiversity is a global challenge. Yet, it is particularly acute in developing countries where biodiversity is high and food-security low. There is an ongoing debate whether land for nature and for agriculture should be segregated (land sparing) or integrated (land sharing). While these strategies still need unambiguous empirical validation, we here illustrate the real-word complexity of this issue by focusing on the case of Kenya, hosting one of the fastest growing populations in the world. We discuss historical effects and those arising from recent demographic pressure, and integrate these with biotic and abiotic constraints (soil fertility and climate) that additionally challenge land sparing and sharing strategies for biodiversity conservation. Generically, our contribution stresses the importance of recognising the specific context in which land-use strategies are to be applied, and underline the need of a deeper understanding of local conditions. This work goes beyond the current theoretical and highly abstract land-use debate that has been published in high impact journals but which may be less efficient on solving local conflicts.