Do single Pollard transects represent the local butterfly community? A case study from the Spitzberg near Tübingen, Germany

• Published in: Insect Conservation and Diversity
• Main Author: Gottschalk, Thomas K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Pollard; Spitzberg
• Online Access: http://dx.doi.org/10.1111/icad.12437; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Ficad.12437; https://onlinelibrary.wiley.com/doi/pdf/10.1111/icad.12437; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/icad.12437

Abstract Information on butterfly population size and distribution is a key tool for verifying species conservation status. Such data are rare and tend to be available on local rather than on regional scales. One important data source are monitoring schemes that have been implemented in several countries, e.g. the German butterfly monitoring scheme (TMD). The main goal of the present study was to examine how representative single transects of the TMD are able to identify local or regional diversity patterns of butterflies. Total butterfly population size, density of individuals and species diversity pattern of a 624 ha large study area (Spitzberg) were recorded by intensive surveys. Almost all butterfly species present at the Spitzberg were recorded by the TMD transects. For 22 species, local estimates based on records of the TMD transects ranged between 0 and 10% of the regional population size. Accordingly, the study demonstrates that population size changes of most of the species can potentially be identified. Increasing cover of forest has a negative effect on species diversity and butterfly density, while the cover of nutrient‐poor grassland and the diversity of biotope types has a positive impact on butterfly density and species diversity. Solar insolation has a positive effect on butterfly density. Based on the results of the species–habitat relationships, the location of TMD transects could be optimised by aiming to cover the complete butterfly diversity of the study area. Additionally, monitoring of some of the species might be improved if winter surveys of eggs and larvae were implemented in the monitoring scheme.