Spiders and other invertebrates
Spiders are characterised by a great taxonomic diversity and their high specificity for habitats. They respond relatively quickly to changes in land-use and are therefore a good ecological indicator. For South Tyrol almost 900 spider species have been described.
Millipedes and Centipedes are the third most diverse class of terrestrial arthropods, following insects and arachnids. Millipedes have a crucial role in fragmentation and decomposition of leaf litter, while centipedes are agile predators. In total we find about 85 millipede and 50 centipede species in South Tyrol.
Earthworms are important detritivores and are essential in composting and recycling soil nutrients. They contribute to a good soil structure and help with its aeration and drainage. Together with other soil biota, they represent an important source of food for polyphagous predators. So far 22 earthworm species have been found in South Tyrol.
Methods: In order to collect the surface-active invertebrate fauna, pitfall traps are installed twice a year: once in late spring/early summer and once in late summer/early autumn. In high-mountain sites we only conduct one sampling campaign per year (i.e. in the summer months). In order to collect the soil fauna, soil core samples are taken. The samples are heat extracted afterwards. Besides the mentioned taxonomical groups many other different invertebrate groups (e.g. mites and pseudoscorpions) are caught with the methods previously described. Various insect groups like beetles and bugs are also sampled by applying pitfall traps and soil extraction.