When to sample in an inaccessible landscape: a case study with carabids from the Allgäu (northern Alps) (Coleoptera, Carabidae)

Abstract

While pitfall trapping is generally accepted as the standard method for sampling carabid beetles, this method has rarely been used in mountain ecosystems, mainly due to the high labour intensity it involves. As part of a research project in the German Alps, we investigated the phenologic appearance of adult carabid beetles in mountain ecosystems along with the consequences of possible reductions in sampling periods. Our results show that an early activity peak among carabids is predominant in mountain ecosystems. However, there are differences among species: the main group of species showed the highest activity directly after snow melt, a second group showed a delayed activity peak and a small third group had no clear peak at all. Based on this study, we recommend two fortnightly sampling periods as a minimum for a sampling programme: one immediately after snow melt, and a second sampling period after a pause of two weeks.

Protected habitats of Natura 2000 do not coincide with important diversity hotspots of arthropods in mountain grasslands

“…In the Alps, the efforts can be focused on taxa with a large number of endemic species, since these are often of greatest conservation concern. Here, we see the groups of arthropods that we studied as one valuable complement to vascular plants, which is practicable especially as a reduced sampling design gives representative results (Harry et al ., ). A taxonomically broader approach could give us better local knowledge about biodiversity and identification of specific sites that are of particular relevance for the conservation of often neglected taxa.…”

“…Pitfall traps were opened for 2 weeks in June (just after the first snowmelt at the ridge) and in early July. This sampling scheme was shown to be adequate for carabid beetles in these mountain habitats (Harry et al ., ). All plots were sampled in the context of a conservation project between 2003 and 2008.…”

Global warning: challenges, threats and opportunities for ground beetles (Coleoptera: Carabidae) in high altitude habitats

“…It would be clearly important to develop a sampling protocol that is as easy as possible to carry out, both in terms of time-effectiveness and labor intensity due to the constraints imposed by the physical effort of working at high altitudes: walk for several hours off the beaten paths, weather instability, and a heavy backpack. On the base of the available methodological studies performed at high altitude (HARRY et al 2011;GOBBI et al 2018) the following suggestions can be provided: i) an early activity peak is predominant among carabids in mountain ecosystems, thus the sampling season should starts just after the snow melts (generally early July), ii) two fortnightly sampling sessions are recommended to obtain a species inventory, while three to five sampling sessions are suggested to obtain data on population dynamics and population size (activity density), iii) three to six traps, located about 10 m apart, are needed for each sampling plot (= area with uniform environmental features), iv) use plastic pots (diameter 7 cm, height 10 cm) that are smaller than those commonly used (diameter 9 cm, height 11cm; 150 ml of preservative solution). A smaller trap permits the use of less preservative (ca.…”

Hand searching versus pitfall trapping: how to assess biodiversity of ground beetles (Coleoptera: Carabidae) in high altitude equatorial Andes?

“…Our results indicate that a complete survey of species diversity is more easily reached in high altitude tropical habitats, with only four sampling sessions. However, the required sampling effort is still twice more time consuming in the Ecuadorian páramo than in temperate alpine habitats, as it has been reported that only two sampling sessions are enough in the Alps to get an exhaustive view of the species assemblages (Harry et al 2011).…”