Mark Frenzel

Spatial genetic structure in a metapopulation of the land snail Cepaea nemoralis (Gastropoda: Helicidae)

Habitat fragmentation is a major force affecting demography and genetic structure of wild populations, especially in agricultural landscapes. The land snail Cepaea nemoralis (L.) was selected to investigate the impact of habitat fragmentation on the spatial genetic structure of an organism with limited dispersal ability. Genetic and morphological patterns were investigated at a local scale of a 500 m transect and a mesoscale of 4 × 4 km in a fragmented agricultural landscape while accounting for variation in the landscape using least‐cost models. Analysis of microsatellite loci using expected heterozygosity (HE), pairwise genetic distance (FST/1 − FST) and spatial autocorrelograms (Morans I) as well as shell characteristics revealed spatial structuring at both scales and provided evidence for a metapopulation structure. Genetic diversity was related to morphological diversity regardless of landscape properties. This pointed to bottlenecks caused by founder effects after (re)colonization. Our study suggests that metapopulation structure depended on both landscape features and the shape of the dispersal function. A range of genetic spatial autocorrelation up to 80 m at the local scale and up to 800 m at the mesoscale indicated leptokurtic dispersal patterns. The metapopulation dynamics of C. nemoralis resulted in a patchwork of interconnected, spatially structured subpopulations. They were shaped by gene flow which was affected by landscape features, the dispersal function and an increasing role of genetic drift with distance.

Diversity and composition of phytophagous insect guilds on Brassicaceae

Abstract We investigated the guild structure of phytophagous insects on Brassicaceae in Poland and the influence of host-plant parameters (e.g. sampling effort, geographical distribution, taxonomic isolation, nitrogen indicator values) on the species richness of these guilds. The data were extracted from a study published by Lipa et al. The overall number of recorded ectophagous species is about twice the number of endophagous species. Irrespective of the feeding niche, species are predominantly oligophagous, feeding on more than two Brassicaceae genera. The relative importance of endophagous species within the fauna decreases with increasing host range. The sampling effort predicts a high proportion of the variance of alpha-diversity in oligo- and polyphagous insects, but only a low proportion in specialized species. After correction for sampling effort, most of the plant parameters do not explain an additional proportion of the variance in species richness. We hypothesize that the uniform chemical defence system across genera in Brassicaceae is an important factor triggering host range and diversity patterns in phytophagous insects on crucifers.

The next generation of site-based long-term ecological monitoring: Linking essential biodiversity variables and ecosystem integrity

Global change effects on biodiversity and human wellbeing call for improved long-term environmental data as a basis for science, policy and decision making, including increased interoperability, multifunctionality, and harmonization. Based on the example of two global initiatives, the International Long-Term Ecological Research (ILTER) network and the Group on Earth Observations Biodiversity Observation Network (GEO BON), we propose merging the frameworks behind these initiatives, namely ecosystem integrity and essential biodiversity variables, to serve as an improved guideline for future site-based long-term research and monitoring in terrestrial, freshwater and coastal ecosystems. We derive a list of specific recommendations of what and how to measure at a monitoring site and call for an integration of sites into co-located site networks across individual monitoring initiatives, and centered on ecosystems. This facilitates the generation of linked comprehensive ecosystem monitoring data, supports synergies in the use of costly infrastructures, fosters cross-initiative research and provides a template for collaboration beyond the ILTER and GEO BON communities.

Development of LTSER Platforms in LTER-Europe: Challenges and Experiences in Implementing Place-Based Long-Term Socio-ecological Research in Selected Regions

This chapter introduces place-based, Long-Term Socio-Ecological Research (LTSER) Platforms conceptually and in practice. LTER-Europe has put strong emphasis on utilising the data legacy and infrastructure of traditional LTER Sites for building LTSER Platforms. With their unique emphasis on socio-ecological research, LTSER Platforms add a new and important dimension to the four pillars of LTER-Europe’s science strategy (systems approach, process-oriented, long-term and site-based). In this chapter, we provide an overview of the regionalised or place-based LTSER concept, including experiences garnered from Platform models tested within LTER-Europe, and we discuss the current status of LTSER Platforms on the European continent. The experiences gathered in 6 years of practical work and development of regional socio-ecological profiles as conceptual frameworks in the Austrian Eisenwurzen LTSER Platform will be used to assess weaknesses and strengths of two implementation strategies (evolutionary vs. strategically managed) and to derive recommendations for the future. The chapter represents the close of the first substantive loop of LTSER research that began in 2003 from conceptualisation to implementation and, through the introspective analysis here, a reconsideration of the central concepts.

Hosts as habitats: faunal similarity of phytophagous insects between host plants

1. Published lists on the phytophages recorded on 86 cabbage plant species (Brassicaceae) and 30 thistle species (Cynaroideae) were used to investigate patterns in the faunal similarity of phytophages. This was done by calculating the Jaccard index and a standardised index of similarity between pairs of host species using presence/absence data.

Long-term environmental monitoring infrastructures in Europe: observations, measurements, scales, and socio-ecological representativeness

The challenges posed by climate and land use change are increasingly complex, with ever-increasing and accelerating impacts on the global environmental system. The establishment of an internationally harmonized, integrated, and long-term operated environmental monitoring infrastructure is one of the major challenges of modern environmental research. Increased efforts are currently being made in Europe to establish such a harmonized pan-European observation infrastructure, and the European network of Long-Term Ecological Research sites - LTER-Europe - is of particular importance. By evaluating 477 formally accredited LTER-Europe sites, this study gives an overview of the current distribution of these infrastructures and the present condition of long-term environmental research in Europe. We compiled information on long-term biotic and abiotic observations and measurements and examined the representativeness in terms of continental biogeographical and socio-ecological gradients. The results were used to identify gaps in both measurements and coverage of the aforementioned gradients. Furthermore, an overview of the current state of the LTER-Europe observation strategies is given. The latter forms the basis for investigating the comparability of existing LTER-Europe monitoring concepts both in terms of observational design as well as in terms of the scope of the environmental compartments, variables and properties covered.

Long-Term Ecosystem Research Between Theory and Application – An Introduction

Ecosystems are dynamic entities. Triggered by external and internal factors, ecosystems change on a multitude of spatial and temporal scales. Nevertheless, in the past, the analysis of ecosystem dynamics has had top priority with reference to short time spans. The exploration of ecological interrelations usually has been carried out within a time period of 3 years, due to the typical funding and qualification duration of environmental research projects. As a consequence, to a great extent, the impacts of changes in the long-term have been neglected. This tendency has provoked a lack of information and methodological know how in this area. That strategy of course is not consistent with the long-term, precautionary way of thinking and acting expressed in political manifestations like the 2010 biodiversity target of the CBD or the EU Habitats Directive, which is an essential component of the sustainability principle. Additionally, real life has demonstrated the general significance of long-term processes: global climate change with its multiple consequences has fostered the awareness that there is an essential lack of scientific knowledge to build the ground for answers to the urgent long-term problems of mankind and the biosphere per se arising from these issues.

Towards the co-ordination of terrestrial ecosystem protocols across European research infrastructures

Abstract The study of ecosystem processes over multiple scales of space and time is often best achieved using comparable data from multiple sites. Yet, long‐term ecological observatories have often developed their own data collection protocols. Here, we address this problem by proposing a set of ecological protocols suitable for widespread adoption by the ecological community. Scientists from the European ecological research community prioritized terrestrial ecosystem parameters that could benefit from a more consistent approach to data collection within the resources available at most long‐term ecological observatories. Parameters for which standard methods are in widespread use, or for which methods are evolving rapidly, were not selected. Protocols were developed by domain experts, building on existing methods where possible, and refined through a process of field testing and training. They address above‐ground plant biomass; decomposition; land use and management; leaf area index; soil mesofaunal diversity; soil C and N stocks, and greenhouse gas emissions from soils. These complement existing methods to provide a complete assessment of ecological integrity. These protocols offer integrated approaches to ecological data collection that are low cost and are starting to be used across the European Long Term Ecological Research community.

Modelling patterns of pollinator species richness and diversity using satellite image texture

Assessing species richness and diversity on the basis of standardised field sampling effort represents a cost- and time-consuming method. Satellite remote sensing (RS) can help overcome these limitations because it facilitates the collection of larger amounts of spatial data using cost-effective techniques. RS information is hence increasingly analysed to model biodiversity across space and time. Here, we focus on image texture measures as a proxy for spatial habitat heterogeneity, which has been recognized as an important determinant of species distributions and diversity. Using bee monitoring data of four years (2010–2013) from six 4 × 4 km field sites across Central Germany and a multimodel inference approach we test the ability of texture features derived from Landsat-TM imagery to model local pollinator biodiversity. Textures were shown to reflect patterns of bee diversity and species richness to some extent, with the first-order entropy texture and terrain roughness being the most relevant indicators. However, the texture measurements accounted for only 3–5% of up to 60% of the variability that was explained by our final models, although the results are largely consistent across different species groups (bumble bees, solitary bees). While our findings provide indications in support of the applicability of satellite imagery textures for modeling patterns of bee biodiversity, they are inconsistent with the high predictive power of texture metrics reported in previous studies for avian biodiversity. We assume that our texture data captured mainly heterogeneity resulting from landscape configuration, which might be functionally less important for wild bees than compositional diversity of plant communities. Our study also highlights the substantial variability among taxa in the applicability of texture metrics for modelling biodiversity.

On the Way to an Integrative Long-Term Ecosystem Research – Milestones, Challenges, and some Conclusions

Long-Term Ecosystem Research has been successfully carried out for some decades now, but networking, tuning, and harmonization at least in Europe have just started. Several developmental targets have been obtained and very interesting results have been achieved. Regrettably, these milestones have been reached in a few regional cases only, and, i.e., due to the relatively short-term existence of long-term environmental investigations on the global scale, many urgent questions – with existential problems of mankind among them – could not be answered up to now. In spite of the comprehensive demands for future research including the global scale, some of the key queries may be discussed constructively. Therefore, as an attempt to summarize the complex information of the previous papers, we might refer to the questions which have been asked in the introduction of the book.