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Policy makers and farmers need to know the status of farmland biodiversity in order to meet conservation goals and evaluate management options. Based on a review of 11 monitoring programs in Europe and North America and on related literature, we identify the design choices or attributes of a program that balance monitoring costs and usefulness for stakeholders. A useful program monitors habitats, vascular plants, and possibly faunal groups (ecosystem service providers, charismatic species) using a stratified random sample of the agricultural landscape, including marginal and intensive regions. The size of landscape samples varies with the grain

of the agricultural landscape; for example, samples are smaller in Europe and larger in North America. Raw data are collected in a rolling survey, which distributes sampling over several years. Sufficient practical experience is now available to implement broad monitoring schemes on both continents. Technological developments in remote sensing, metagenomics, and social media may offer new opportunities for affordable farmland biodiversity monitoring and help to lower the overall costs of monitoring programs.

Herzog, F., & Franklin, J. (2016). State-of-the-art practices in farmland biodiversity monitoring for North America and Europe. Ambio, 45(8), 857–871. https://doi.org/10.1007/s13280-016-0799-0

Aim To investigate the performance and relative importance of abiotic and biotic predictors of species richness of three taxa in forest-dominated landscapes across an environmentally heterogeneous mountain region.

Location Switzerland (central Europe).

Methods We used a broad set of nationally available environmental predictors grouped into (1) climate, (2) topography and soil and (3) 3-D vegetation structure derived from airborne Light Detection and Ranging (LiDAR) data to spatially predict the forest species richness of vascular plants, butterflies and breeding birds. We used presence data of 212 plant, 157 butterfly and 92 bird species from multiple transect samples in > 220 1 km² squares at elevations between 261 and 2123 m a.s.l. across 41,248 km². We applied an ensemble modelling approach consisting of five modelling techniques and evaluated their predictive performance using the cross-validated percentage of explained variance of each predictor group separately and the combinations thereof. We investigated the relative importance and response of each predictor and partitioned the variation into independent and shared components per variable group.

Results Climate performed best in predicting forest species richness across taxa. Vegetation structure particularly improved the predictions of butterfly and bird species richness, while soil pH was an important predictor for forest plant species richness. Climate appeared to be mainly indirectly related to butterfly species richness, via correlations with habitat type and structure. The strength and direction of the relationships between the predictors and species richness were taxon-specific with low cross-taxon congruence.

Main conclusions The growing availability of LiDAR data offers powerful new tools for describing vegetation structure and associated animal habitat quality across large areas. This will further our understanding of niche-driven assembly processes in forest landscapes. Although climate was the dominant factor controlling species richness across taxa from different trophic levels, the taxon-specific distributional pattern and response to environmental conditions emphasize the difficulty of accounting for a range of taxa in prioritising biodiversity conservation measures.

Zellweger, F., Baltensweiler, A., Ginzler, C., Roth, T., Braunisch, V., Bugmann, H., & Bollmann, K. (2016). Environmental predictors of species richness in forest landscapes: Abiotic factors versus vegetation structure. Journal of Biogeography, 43(6), 1080–1090. https://doi.org/10.1111/jbi.12696

Large-scale species and genetic metacommunity patterns are influenced by variation in environmental factors and distance between communities, according to previous studies. However, these studies often used different measures to assess patterns of metacommunity diversity, distances between communities and grain sizes at which environmental variables are measured. This hinders interpretations and generalizations of the underlying process that drive metacommunity diversity. We applied a synthetic and multi-analytical approach to identify general factors structuring the diversity of a large riverine metacommunity. Using complementing approaches we analyzed how distance, measured as Euclidean or topological distance, and environmental factors, assessed at different grain sizes, influenced different measures of metacommunity diversity (species richness, functional richness and phylogenetic diversity) of mayfly, stonefly and caddisfly species in a large river network (river Rhine, Switzerland). We found the amount of explained variation in species diversity was generally unaffected by grain size, but improved with the use of topological distance, compared to Euclidean distance. Variation in functional diversity was best explained by environmental factors at small grain sizes and topological distance. Variation in phylogenetic diversity was best explained when environmental variables were assessed at larger grain sizes and Euclidean distance was used. Overall, our results indicate that processes structuring metacommunity diversity may differ at the species, functional or phylogenetic level of the community, as recently postulated in the metacommunity–phylogenetics approach. While such differences may hinder comparisons across studies using different methodologies, it offers opportunities to disentangle the structuring factors within metacommunities by applying multiple analytical approaches to the same dataset.

Seymour, M., Deiner, K., & Altermatt, F. (2016). Scale and scope matter when explaining varying patterns of community diversity in riverine metacommunities. Basic and Applied Ecology, 17(2), 134–144. https://doi.org/10.1016/j.baae.2015.10.007

Cryptic species are phylogenetically diverged taxa that are morphologically indistinguishable and may differ in their ecological and behavioral requirements. This may have important implications for ecosystem services and conservation of biodiversity. We investigated whether two ecologically important cryptic species of the freshwater amphipod Gammarus fossarum (types A and B) are associated with different habitats. We collected data on their occurrence at both the landscape scale (large watersheds) and at the local scale (river reach) to compare macro- and microscale environmental parameters associated with their presence. Analysis of the landscape scale data showed that occurrence of types A and B differ with respect to watershed and river size and, interestingly, human impact on river ecomorphology. Whereas type B was mainly found in less forested areas with higher human impact, type A showed the opposite occurrence pattern. Analyses of the local scale data suggested that habitats occupied by type A were characterized by larger gravel, larger stones and less macrophytes than habitats occupied by type B. The landscape and local data set showed contradicting patterns with regard to stream size. Overall, the observed differences between the two types of G. fossarum most likely reflect ecological differences between them, but alternative explanations (e.g., historical colonization processes) cannot be completely ruled out. Our study underlines that common cryptic species can differ in their ecology and response to anthropogenic influence. Such differences in habitat requirements among difficult-to-identify taxa present a challenge for biodiversity and ecosystem management. Our results emphasize the importance of conservative and precautionary approaches in maintenance of habitat diversity and environmental heterogeneity.

Eisenring, M., Altermatt, F., Westram, A. M., & Jokela, J. (2016). Habitat requirements and ecological niche of two cryptic amphipod species at landscape and local scales. Ecosphere, 7(5). https://doi.org/10.1002/ecs2.1319