Long-term dynamics of the abundance of earthworms and enchytraeids (Annelida, Clitellata: Lumbricidae, Enchytraeidae) in forests of the Central Urals, Russia

Since the late 1980s, long-term monitoring of terrestrial ecosystems in metal-contaminated areas has been carried out in the Central Urals. As a part of these monitoring programmes, the data on soil macroinvertebrates in undisturbed areas as reference sites continues to be gathered. These data help study the local biodiversity and long-term dynamics of soil macroinvertebrate abundance in non-polluted areas. The dataset (available from the GBIF network at https://www.gbif.org/dataset/bf5bc7f6-71a3-4abd-8abc-861ee3cbf84a) includes information from a long-term monitoring programme for two taxa of Annelids, Lumbricidae and Enchytraeidae, which dwell in the topsoil of spruce-fir, birch, pine and floodplain forests in the Central Urals. The dataset includes information on the earthworm community structure (list of species, species abundance, number of egg cocoons, cocoon exuvia, juveniles and adults) and enchytraeid abundance. The dataset consists of 553 sampling events (= samples, corresponding to upper and lower layers of the soil monoliths) and 12739 occurrences (earthworms, mainly identified to species and earthworm cocoons and enchytraeids, identified to family) collected during 1990–1991, 2004, 2014–2016 and 2018–2020. In total, 3305 individuals of earthworms were collected, representing ten (out of twelve) species and all eight genera recorded for the fauna of the Central Urals. In addition, 7292 earthworm egg cocoons and cocoon exuvia and 6926 individuals of enchytraeids were accumulated. The presence-absence data on each of the ten earthworm species, egg cocoons, cocoon exuvia and enchytraeids are provided for each sampling event. All data were collected in undisturbed non-polluted areas and are used as a local reference for ecotoxicological monitoring. The dataset provides valuable information for estimating the composition and abundance of earthworm communities in different habitats over a long time and contributes to the study of soil fauna biodiversity in the Urals.

Effect of Fallowed and Cultivated Land Use Systems on the Composition and Abundance of Soil Macroinvertebrates Assemblage in Uruk Osung Community, Akwa Ibom State, Nigeria

This study was to assess the effect of fallowed and cultivated land-use systems on the abundance of soil macroinvertebrates assemblage. Collections of soil samples were carried out fortnightly twice a month for four months. The extraction of soil macroinvertebrates was carried out using Berlese-Tullgren funnel extractor, and elutriation technique. The mean values of 6.93+/-0.25 were recorded for pH, 32.08+/-0.52oC for temperature, 15.60+/-1.22 for moisture content, were recorded for fallowed soil, and 4.43+/-0.16 (pH), 30.95+/-0.19oC (temperature) were recorded for cultivated soil. A total of 17 soil macroinvertebrates species comprising of 11 orders, from four classes were encountered. Out of the 517 individual soil macroinvertebrates encountered, 327 individuals representing four classes were present in the fallow land while 190 individuals representing three classes were present in the cultivated land. The most dominant species in terms of abundance in the fallowed land site included; Cryptotermes sp 67(20.49%) > Blatta sp 56(17.12%) with Hogna sp 1(0.0.30%) the least; while Cryptotermes sp. 79(41.58%) >Lasius sp 30(15.79%) > Lumbricus terrestris 21(11.05%) represents the dominant species in the cultivated soil with Paraponera sp 1(0.53%) the least. Soil temperature showed positive correlation with the abundance of Clitellata (r = 0.851; p < 0.05) and Insecta (r = 0.826; p < 0.05) and Soil pH showed positive correlation with the abundance of Diplopoda (r = 0.911; p ≤ 0.05). In conclusion, it could be deduced from the study that human activities in the cultivated site perturb soil macroinvertebrates community structure which is reflected in the relative abundance of soil macroinvertebrate from the two sampling sites. The results obtained in this study could be a piece of pointing information for the conservation and management of the soil macroinvertebrates giving their functions in balancing agroecosystems.

Is the Polylactic Acid Fiber in Green Compost a Risk for Lumbricus terrestris and Triticum aestivum?

Polylactic acid (PLA) bioplastic was introduced to the market as an environmentally friendly potential solution for plastic pollution. However, the effects of bioplastic debris mixed with composts on soil macroinvertebrates, plant growth and soil conditions are still unknown. Soil macroinvertebrates are soil health indicators. A reduction in their abundance is a sign of soil degradation. The objectives of this study were (i) to assess PLA debris in greenhouse composts, and (ii) to test the ecotoxicological effects of PLA debris mixed with compost on Lumbricus terrestris, a soil organism model, and on Triticum aestevium, a plant growth model. The study was comprised of three stages: (1) determine the PLA debris size distribution in composts; (2) assess the ecotoxicological effects of real-world concentrations (0% to 5%) of PLA mixed with compost on earthworm mortality and reproduction; and (3) assess the influence of compost mixed with real-world PLA concentrations on plant growth and physicochemical soil conditions. One percent of PLA debris was found in green composts, 40% of composted PLA debris measured between 1–10 mm, with a concentration of 82.8 ± 17.4 microplastics.gram−1 compost. A concentration of 1% PLA in composts resulted in significant mortality in earthworms. No significant effects of PLA mixed with composts were observed on plant growth or soil physicochemical conditions. Further studies are required in order to test the effect of this biopolymer on different earthworm and plant’ species.

Abundance and diversity of soil macroinvertebrates in sugarcane (Saccharum spp.) plantations under organic and chemical fertilization in Belize

Many studies suggest that sugarcane management practices have negative impact on soil quality, especially on soil organisms, however, information on macroinvertebrate abundance and diversity in conventional sugarcane fields is scarce. This study determined the abundance and diversity of soil macroinvertebrates in sugarcane plantations under 2 types of soils, Cambisol and Fluvisol, with three types of fertilizer management: chemical fertilizer, vinasse and filter mud, and in a secondary forest (on a Cambisol). Sampling was carried out in northern Belize during two crop cycles (from May 2013 to May 2015). Soil macroinvertebrates were collected using monoliths based on Tropical Soil Biology and Fertility (TSBF) Handbook of Methods at the end of the rainy seasons. The parameters evaluated were biomass, density and diversity of soil macroinvertebrates (number of morphospecies, an ecological index for tropical soil quality based on macrofauna, and a converted Shannon index (H_exp)), yield and plant response variables (number of stool, number of stem, number of active leaves, stem length and stem diameter). A total of 7,634 individuals were identified, grouped into 52 morphospecies belonging to 16 orders and three species of annelids. No significant differences existed among management systems (application of chemical fertilizer, vinasse, filter mud and secondary forest) on abundance and diversity of soil macroinvertebrates, yield and plant variables. However, there were significant differences between soils and cycles in some evaluated parameters. Presuming that soil type and seasonal conditions, in a two years trial, had higher weight on determine the studied parameters than the different management systems.