Bernd Gruber

Advantages of Volunteer-Based Biodiversity Monitoring in Europe

Without robust and unbiased systems for monitoring, changes in natural systems will remain enigmatic for policy makers, leaving them without a clear idea of the consequences of any environmental policies they might adopt. Generally, biodiversity-monitoring activities are not integrated or evaluated across any large geographic region. The EuMon project conducted the first large-scale evaluation of monitoring practices in Europe through an on-line questionnaire and is reporting on the results of this survey. In September 2007 the EuMon project had documented 395 monitoring schemes for species, which represents a total annual cost of about 4 million euro, involving more than 46,000 persons devoting over 148,000 person-days/year to biodiversity-monitoring activities. Here we focused on the analysis of variations of monitoring practices across a set of taxonomic groups (birds, amphibians and reptiles, mammals, butterflies, plants, and other insects) and across 5 European countries (France, Germany, Hungary, Lithuania, and Poland). Our results suggest that the overall sampling effort of a scheme is linked with the proportion of volunteers involved in that scheme. Because precision is a function of the number of monitored sites and the number of sites is maximized by volunteer involvement, our results do not support the common belief that volunteer-based schemes are too noisy to be informative. Just the opposite, we believe volunteer-based schemes provide relatively reliable data, with state-of-the-art survey designs or data-analysis methods, and consequently can yield unbiased results. Quality of data collected by volunteers is more likely determined by survey design, analytical methodology, and communication skills within the schemes rather than by volunteer involvement per se.

Food web structure and biocontrol in a four-trophic level system across a landscape complexity gradient

Decline in landscape complexity owing to agricultural intensification may affect biodiversity, food web complexity and associated ecological processes such as biological control, but such relationships are poorly understood. Here, we analysed food webs of cereal aphids, their primary parasitoids and hyperparasitoids in 18 agricultural landscapes differing in structural complexity (42–93% arable land). Despite little variation in the richness of each trophic group, we found considerable changes in trophic link properties across the landscape complexity gradient. Unexpectedly, aphid–parasitoid food webs exhibited a lower complexity (lower linkage density, interaction diversity and generality) in structurally complex landscapes, which was related to the dominance of one aphid species in complex landscapes. Nevertheless, primary parasitism, as well as hyperparasitism, was higher in complex landscapes, with primary parasitism reaching levels for potentially successful biological control. In conclusion, landscape complexity appeared to foster higher parasitism rates, but simpler food webs, thereby casting doubt on the general importance of food web complexity for ecosystem functioning.

Integrating ongoing biodiversity monitoring: potential benefits and methods

Halting the loss of biodiversity comes along with the need to quantify biodiversity composition and dynamics at large spatial and temporal scales. Highly standardized, international monitoring networks would be ideal, but they do not exist yet. If we are to assess changes in biodiversity now, combining output available from ongoing monitoring initiatives is the only option. However, integration of biodiversity information across schemes is still very poorly developed. In this paper, we outline practical issues to be considered when planning to combine existing monitoring information. First, we provide an overview of avenues for integration along the four dimensions that characterize a monitoring design: sample size, biological coverage, spatial coverage and temporal coverage. We also emphasize that complementarity in monitoring targets across schemes enables to describe complex processes of biodiversity dynamics, e.g. through relating species traits to the impacts of environmental changes. Second, we review some methods to overcome differences in designs among monitoring schemes, such as site selection, post-stratification and measurement error. Finally, we point out some commonly used statistical methods that are at hand for combining data or parameter estimates. We especially emphasize the possible levels of data integration (raw data, parameter estimates, or effect size estimates), and the largely under-exploited potential of meta-analysis methods and weighted analyses. This contribution aims to bolster the practice and use of integration of ongoing monitoring initiatives for biodiversity assessment.

PopGenReport: simplifying basic population genetic analyses in R

Summary 1. Using scripting languages such as R to perform population genetic analyses can improve the reproducibility of research, but using R can be challenging for many researchers due to its steep learning curve. 2. POPGENREPORT is a new R package that simplifies performing population genetics analyses in R, through the use of a new report-generating function. The function POPGENREPORT allows users to perform up to 13 pre-defined and 1 user-defined analyses through the use of a single command line. Each analysis generates figures and tables that are incorporated into a PDF report and are also made available as individual files (figures are provided in multiple formats, table contents are provided as CSV files). 3. The package includes new R functions that simplify the importation of data from a spreadsheet file, examine allele distributions across populations and loci and identify private alleles, determine pairwise individual genetic distances using the methods of Smouse and Peakall (1999) and Kosman and Leonard (2005), respectively, detect the presence of null alleles, calculate allelic richness, and test for spatial autocorrelation in genotypes using the methods of Smouse and Peakall (1999). 4. The package has a modular structure that makes the process of adding new functionality straightforward. To facilitate the addition of user-designed functions, the package includes a fully customizable module that can be automatically included in the PDF report. 5. To support users not experienced in R, the website (www.popgenreport.org) has a tutorial for the package and a downloadable, portable version of the package with LaTeX pre-configured for the Windows operating system.

National responsibilities in European species conservation: a methodological review.

One particular challenge in reducing the loss of biodiversity by 2010, as agreed on at the Earth Summit in 2002, is to assign conservation tasks to geographic or administrative entities (e.g., countries or regions) on different geographical scales. To identify conservation tasks, it is imperative to determine the importance of a specific area for the global survival of a species. So far, these national or subnational responsibilities for the conservation of species have been included differently in methods prioritizing conservation. We reviewed how 12 European and 3 non-European methods determined national conservation responsibilities and evaluated the international importance of a biological population. Different countries used different methodologies, which made a direct comparison of assessments of national responsibilities among countries extremely difficult. Differences existed in the importance criteria used. Criteria included population decline, range reduction, rarity status, degree of isolation of a population, endemism, proportional distribution, and geographic location. To increase comparability, it is imperative to develop criteria for which data are generally available and to standardize the methodology among countries. A standardized method would allow conservation decisions to be based on the conservation status of a species and on the responsibility of a geographic or administrative entity for the survival of a species. We suggest that such a method should use a scalable index of proportional distribution, taxonomic status, and the distribution pattern of a taxon or species as key elements. Such a method would allow for the creation of hierarchical lists and would be highly relevant for parts of the world with multiple political jurisdictions or state unions and for nations with regional governmental structures. Conservation priorities could then be reasonably set by combining national responsibility assessments with the international conservation status of a species.

Evolution of climate niches in European mammals

Our ability to predict consequences of climate change is severely impaired by the lack of knowledge on the ability of species to adapt to changing environmental conditions. We used distribution data for 140 mammal species in Europe, together with data on climate, land cover and topography, to derive a statistical description of their realized climate niche. We then compared climate niche overlap of pairs of species, selected on the basis of phylogenetic information. In contrast to expectations, related species were not similar in their climate niche. Rather, even species pairs that had a common ancestor less than 1 Ma already display very high climate niche distances. We interpret our finding as a strong interspecific competitive constraint on the realized niche, rather than a rapid evolution of the fundamental niche. If correct, our results imply a very limited usefulness of climate niche models for the prediction of future mammal distributions.

A review and a framework for the integration of biodiversity monitoring at the habitat level

The monitoring of biodiversity at the level of habitats is becoming widespread in Europe and elsewhere as countries establish national habitat monitoring systems and various organisations initiate regional and local schemes. Parallel to this growth, it is increasingly important to address biodiversity changes on large spatial (e.g. continental) and temporal (e.g. decade-long) scales, which requires the integration of currently ongoing monitoring efforts. Here we review habitat monitoring and develop a framework for integrating data or activities across habitat monitoring schemes. We first identify three basic properties of monitoring activities: spatial aspect (explicitly spatial vs. non-spatial), documentation of spatial variation (field mapping vs. remote sensing) and coverage of habitats (all habitats or specific habitats in an area), and six classes of monitoring schemes based on these properties. Then we explore tasks essential for integrating schemes both within and across the major classes. Finally, we evaluate the need and potential for integration of currently existing schemes by drawing on data collected on European habitat monitoring in the EuMon project. Our results suggest a dire need for integration if we are to measure biodiversity changes across large spatial and temporal scales regarding the 2010 target and beyond. We also make recommendations for an integrated pan-European habitat monitoring scheme. Such a scheme should be based on remote sensing to record changes in land cover and habitat types over large scales, with complementary field mapping using unified methodology to provide ground truthing and to monitor small-scale changes, at least in habitat types of conservation importance.

An optimisation approach to increase DNA amplification success of otter faeces

Faeces have proved to be a suitable non-invasive DNA source for microsatellite analysis in wildlife research. For the success of such studies it is essential to obtain the highest possible PCR amplification success rate. These rates are still relatively low in most carnivorous species, especially in the otter (Lutra lutra). We therefore optimised the entire microsatellite genotyping process by combining our findings with results from previous studies to gain a high rate of reliable genotypes. We investigated the influence of otter faecal quality in relation to the quantity of slimy secretions and three levels of storage periods at −20°C on amplification success. Further, we tested the cost-effective and time-saving Chelex extraction method against the profitable QIAamp® DNA Stool Kit (Qiagen), and compared three PCR methods - a standard single-step PCR protocol, a single-locus two-step PCR procedure and a multiplex two-step PCR procedure - regarding success rate and genotyping errors. The highest amplification success rate (median: 94%; mean: 78%) was achieved using faecal samples consisting only of jelly extracted with the QIAamp® DNA Stool Mini Kit (Qiagen) immediately after collection and amplified following the time and cost efficient multiplex two-step PCR protocol. The two-step procedure, also referred to as pre-amplification approach, turned out to be the main improvement as it increases amplification success about 11% and reduces genotyping errors about 53%, most notably allelic dropouts.

Can Genetic Estimators Provide Robust Estimates of the Effective Number of Breeders in Small Populations

The effective population size (Ne) is proportional to the loss of genetic diversity and the rate of inbreeding, and its accurate estimation is crucial for the monitoring of small populations. Here, we integrate temporal studies of the gecko Oedura reticulata, to compare genetic and demographic estimators of Ne. Because geckos have overlapping generations, our goal was to demographically estimate NbI, the inbreeding effective number of breeders and to calculate the NbI/Na ratio (Na = number of adults) for four populations. Demographically estimated NbI ranged from 1 to 65 individuals. The mean reduction in the effective number of breeders relative to census size (NbI/Na) was 0.1 to 1.1. We identified the variance in reproductive success as the most important variable contributing to reduction of this ratio. We used four methods to estimate the genetic based inbreeding effective number of breeders NbI(gen) and the variance effective populations size NeV(gen) estimates from the genotype data. Two of these methods - a temporal moment-based (MBT) and a likelihood-based approach (TM3) require at least two samples in time, while the other two were single-sample estimators - the linkage disequilibrium method with bias correction LDNe and the program ONeSAMP. The genetic based estimates were fairly similar across methods and also similar to the demographic estimates excluding those estimates, in which upper confidence interval boundaries were uninformative. For example, LDNe and ONeSAMP estimates ranged from 14–55 and 24–48 individuals, respectively. However, temporal methods suffered from a large variation in confidence intervals and concerns about the prior information. We conclude that the single-sample estimators are an acceptable short-cut to estimate NbI for species such as geckos and will be of great importance for the monitoring of species in fragmented landscapes.

On managing the red mason bee (Osmia bicornis) in apple orchards

A worldwide decline of pollinator abundance is recorded and the worldwide pollination of insect-pollinated crops has traditionally depended on a single species, the honeybee. The risks of relying on a single species are obvious. Other species have been developed for particular crops. Here we present an extension of the framework of Bosch and Kemp (2002) that deals on how to develop a bee species into a crop pollinator. We used nesting aids in different settings to address five important issues that are necessary for an effective management of a bee species in a commercial setting. Our study system was the red mason bee (Osmia bicornis) in apple orchards in eastern Germany, but our approach should be transferable to other settings. The first issue was to demonstrate that it is possible to increase population size of O. bicornis by providing nesting aids. Second, we present how someone can study landscape features that promote the occurrence and abundance of O. bicornis. Further, we studied the dispersal of the species inside the orchard, and could demonstrate that bees prefer to disperse along lines of trees. Finally, we studied the effect of nesting substrate and type of farming on the recruitment of bees. We found a close relationship between the length of nesting tubes and achieved sex ratio and a negative effect of conventional farming on the number of nests built. We conclude with recommendations on how our findings can be used to optimize the management of O. bicornis in apple orchards.