The Short-Term Impact of Different Silvicultural Thinnings on Soil Nematode and Microarthropod Biodiversity in Artificial Black Pine Stands

Soil invertebrates represent almost a quarter of the total diversity of living organisms and their activity affects the entire soil ecological process. The choice of adequate thinning systems may differently affect soil nematode and microarthropod biodiversity in artificial black pinewoods. In this work, the results of the impact of different thinnings on the structure of nematode and microarthropod communities was reported. In a short-term experiment, thinning from below and selective thinning were compared to unmanaged stands to provide indications at the regional scale in central Italy. Soil nematode and microarthropod biodiversity was explored by examining community structure, assessing biodiversity. The interaction between environmental variables (crown volume, Photosynthetically Active Radiation, soil texture, soil temperature, and moisture) with taxa abundance of nematodes and microarthropods were also reported. The results indicated that the effects of thinning practices were temporary and varied between years. Soil nematode community shifted during the first and third years of thinning managements only in the Pratomagno site, while soil microarthropod community shifted in both sites only in the second year. The total nematode abundance was minimally affected by thinning practices, while the nematode community composition showed a decrease of omnivores and predators in the first years. Soil indicators showed inconsistent results. In microarthropods, mites and collembola were the least affected by thinning in terms of abundance and species biodiversity, while eu-edaphic taxa of Chilopoda, Diplopoda, and Pauropoda were not influenced by thinning, hemi-edaphic and epi-edaphic taxa of Coleoptera, Diptera, Hymenoptera, Tysanoptera, and Hemiptera were negatively affected. Soil indicators such as Shannon-Weiner and Simpson indices and soil biological quality (QBS-ar) improved in thinning from below in both sites. Soil temperature and moisture were the main driving factors in affecting soil nematode and microarthropods communities. Thinning from below probably allowed a more rapid recovery than selective thinning.