Soil Fauna Diversity - Function, Soil Degradation, Biological Indices, Soil Restoration

Soil represents one of the most important reservoirs of biodiversity. It reflects ecosystem metabolism since all the bio-geo-chemical processes of the different ecosystem components are combined within it; therefore soil quality fluctuations are considered to be a suitable criterion for evaluating the long-term sustainability of ecosystems. Within the complex structure of soil, biotic and abiotic components interact closely in controlling the organic degradation of matter and the nutrient recycling processes. Soil fauna is an important reservoir of biodiversity and plays an essential role in several soil ecosystem functions; furthermore, it is often used to provide soil quality indicators. Although biodiversity was one of the focal points of the Rio conference, in the 1990s virtually no attention was paid to activities for the conservation of soil communities. However, with the new millennium, the conservation of soil biodiversity has become an important aim in international environmental policies, as highlighted in the EU Soil Thematic Strategy (2006), the Biodiversity Action Plan for Agriculture (EU 2001), the Kiev Resolution on Biodiversity (EU/ECE 2003) and afterwards in the Message from Malahide (EU 2004), that lay down the goals of the 2010 Countdown. Human activities frequently cause a degradation of soil environmental conditions which leads to a reduction in the abundance and to a simplification of animal and plant communities, where species able to bear stress predominate and rare taxa decrease in abundance or disappear. The result of this biodiversity reduction is an artificial ecosystem that requires constant human intervention and extra running costs, whereas natural ecosystems are regulated by plant and animal communities through flows of energy and nutrients, a form of control progressively being lost with agricultural intensification. For these reasons the identification of agricultural systems which allow the combination of production targets and environmentally friendly management practices, protecting both soil and biodiversity, is essential in order to prevent the decline of soil fauna communities in agricultural landscapes

Can Grasslands in Photovoltaic Parks Play a Role in Conserving Soil Arthropod Biodiversity?

Under the increasing global energy demand, the new European Union Biodiversity Strategy for 2030 encourages combinations of energy production systems compatible with biodiversity conservation; however, in photovoltaic parks, panels shadowing the effects on soil health and biodiversity are still unknown. This study (location: Northern Italy) aimed to evaluate the effect of ground-mounted photovoltaic (GMPV) systems on soil arthropod biodiversity, considering two parks with different vegetation management: site 1-grassland mowed with tractor; site 2-grassland managed with sheep and donkeys. Three conditions were identified in each park: under photovoltaic panel (row), between the panel rows (inter-row), and around the photovoltaic plant (control). The soil pH and organic matter (SOM), soil arthropod community, biodiversity, and soil quality index (e.g., QBS-ar index) were characterised. Differences between the two GMPVs were mainly driven by the SOM content (higher values where grazing animals were present). No differences were observed in site 1, even if a high heterogeneity of results was observed for the soil biodiversity parameters under the panels. In site 2, SOM and pH, as well as arthropods biodiversity and QBS-ar, showed low values in the row. Soil fauna assemblages were also affected by ground-mounted panels, where Acarina, Collembola, Hymenoptera, and Hemiptera showed the lowest density in the row. This study suggests that ground-mounted solar panels had significant effects on below-ground soil fauna, and was more marked depending on the system management. Furthermore, the results obtained for the inter-row were similar to the control, suggesting that the area between the panel rows could be considered a good hotspot for soil biodiversity

Integrating chemical, biological and soil fauna variables during beech leaf litter decay: A partial least squares approach for a comprehensive view of the decomposition process

Litter decomposition is an ecosystem process that is regulated by a multitude of factors and by their complex interactions. Current decomposition paradigms do not always offer a coherent view of the process because it can be hardly understood without a thorough analysis of interacting factors. Thus, there is a need to further understand the mechanics of litter decay with a comprehensive approach, especially in temperate forest ecosystems where decomposition plays a crucial role in regulating them as source or sink of CO2. Therefore, the aim of this work was to identify the interactions between chemical, biological and soil fauna variables in order to discern driving variables and the changes in their interactions during long-time (1300 days) beech leaf litter decomposition. In order to investigate patterns of variation and co-variation within and between datasets, we used Two-block Partial Least Squares, helping us to interpret the decomposition process with a systemic approach. Our key findings showed that the decomposition process of beech litter in two Mediterranean forests was driven by litter quality at the beginning and in the later stages of decomposition, while edaphic and climatic factors were implied in the central steps, with a dramatic change of scenario around 2.5 years. Simultaneous and interacting changes in chemical variables, extracellular enzyme activities, and soil fauna were shown, with a significant role of lignocellulosic components and enzymes involved in their degradation, Mn residual weight, and abundance of Collembola

Soil microarthropod communities from Mediterranean forest ecosystems in Central Italy under different disturbances

The aim of this study is to assess soil quality in Mediterranean forests of Central Italy, from evergreen to deciduous, with different types of management (coppice vs. high forest vs. secondary old growth) and compaction impacts (machinery vs. recreational). Soil quality was evaluated studying soil microarthropod communities and applying a biological index (QBS-ar) based on the concept that the higher is the soil quality, the higher will be the number of microarthropod groups well adapted to the soil habitat. Our results confirm that hardwood soils are characterised by the highest biodiversity level among growth) and compaction impacts (machinery vs. recreational). terrestrial communities and by a well-structured and mature microarthropod community, which is typical of stable ecosystems (QBS value, >200). While silvicultural practices and forest composition do not seem to influence QBS-ar values or microarthropod community structure, the index is very efficient in detecting soil impacts (soil compaction due to logging activities). Several taxa (Protura, Diplura, Coleoptera adults, Pauropoda, Diplopoda, Symphyla, Chilopoda, Diptera larvae and Opiliones) react negatively to soil compaction and degradation (QBS value, <150). In particular, Protura, Diplura, Symphyla and Pauropoda, are taxonomic groups linked to undisturbed soil. This index could also be a useful tool in monitoring soil biodiversity in protected areas and in urban forestry to prevent the negative effects of trampling. QBS-ar is a candidate index for biomonitoring of soil microarthropod biodiversity across the landscape to provide guidance for the sustainable management of renewable resource and nature conservation

Does the natural "microcosm" created by Tuber aestivum affect soil microarthropods? A new hypothesis based on Collembola in truffle culture

microarthropods play an important role in fungi dispersion, but little is still known about the interaction between truffle and soil microarthropods. The aim of this study was to investigate the ability of the truffle Tuber aestivum to modify soil biogeochemistry (i.e. create a zone of scarce vegetation around the host plant, called a burn or brûlé) and to highlight the effects of the brûlé on the soil fauna community. We compared soil microarthropod communities found in the soil inside versus outside the T. aestivum brûlé with the chemistry of soil collected inside versus outside the brûlé. The study was carried out in three Mediterranean areas, two in Italy and one in Spain. The results confirmed the ability of T. aestivum to modify soil biogeochemistry in the brûlé: pH was higher and total organic carbon tended to be lower inside the brûlé compared to outside. Soil fauna communities showed some interesting differences. Some groups, such as Symphyla and Pauropoda, adapted well to the soil; some Collembolan families, and biodiversity and soil quality indices were generally higher outside the brûlé. Folsomia sp. showed higher abundance in the soil of the brûlé compared to outside. The results suggest that some Collembola groups may be attracted by the fungal metabolites produced by T. aestivum, while other Collembola and other microarthropods may find an unfavourable environment in the soil of the brûlé. The next steps will be to confirm this hypothesis and to extend the study to other keys groups such as nematodes and earthworms and to link fluctuations of soil communities with the biological phases of truffle growth

Food Choice and Fitness of Folsomia candida (Collembola, Isotomidae) Fed on Twelve Species of Truffle

Fungi are a significant food resource for soil fauna, whose grazing behavior can have a significant impact on their development. This relationship is an important aspect in soil functioning, with soil fungi acting as primary agents in decomposition processes. Being one of the most abundant groups among soil fauna, springtails can play a leading role in this context. Despite several previous studies on their epigeous fungal grazing behavior, data regarding the relationship between springtails and truffles are scarce. This study aimed to investigate food preferences of the springtail Folsomia candida for grazing on 12 different species of truffles, 11 belonging to Tuber genus, and 1 to Balsamia genus. We also evaluated how strongly this diet influences survival and reproduction of F. candida. In the first experiment, F. candida were allowed to choose freely between a cereal mixture (choice test) and 12 different species of truffle. In the second experiment, they were fed on the truffles only (no-choice test) for 28 days. Twelve truffle species were analyzed for survival and reproduction of F. candida. F. candida's feeding preference evolved over 72 h, beginning with a strong preference for the control and finally a general preference for truffles. Moreover, Collembola that fed on some Tuber species had a lower survival rate and fewer juveniles per adult compared to the control. Compared to other species, Tuber aestivum and Tuber melanosporum, which are well-known for their ability to produce brûlés, had a positive impact on collembolan fitness, whereas their palatability was not particularly prominent. Hence there was a relationship between diet and fitness in F. candida, whilst hardly any relationship was observed between fitness and feeding preference

Assessing biochar ecotoxicology for soil amendment by root phytotoxicity bioassays

Soil amendment with biochar has been proposed as effective in improving agricultural land fertility and carbon sequestration, although the characterisation and certification of biochar quality are still crucial for widespread acceptance for agronomic purposes. We describe here the effects of four biochars (conifer and poplar wood, grape marc, wheat straw) at increasing application rates (0.5, 1, 2, 5, 10, 20, 50 % w/w) on both germination and root elongation of Cucumis sativus L., Lepidium sativum L. and Sorghum saccharatum Moench. The tested biochars varied in chemical properties, depending on the type and quality of the initial feedstock batch, polycyclic aromatic hydrocarbons (PAHs) being high in conifer and wheat straw, Cd in poplar and Cu in grape marc. We demonstrate that electrical conductivity and Cu negatively affected both germination and root elongation at 655 % rate biochar, together with Zn at 6510 % and elevated pH at 6520 %. In all species, germination was less sensitive than root elongation, strongly decreasing at very high rates of chars from grape marc (>10 %) and wheat straw (>50 %), whereas root length was already affected at 0.5 % of conifer and poplar in cucumber and sorghum, with marked impairment in all chars at >5 %. As a general interpretation, we propose here logarithmic model for robust root phytotoxicity in sorghum, based on biochar Zn content, which explains 66 % of variability over the whole dosage range tested.We conclude that metal contamination is a crucial quality parameter for biochar safety, and that root elongation represents a stable test for assessing phytotoxicity at recommended in-field amendment rates (<1\u20132 %)

Tryptophan concentration is the main mediator of the capacity of adipose mesenchymal stromal cells to inhibit T-lymphocyte proliferation in vitro

n/

C Stocks in Forest Floor and Mineral Soil of Two Mediterranean Beech Forests

This study focuses on two Mediterranean beech forests located in northern and southern Italy and therefore subjected to different environmental conditions. The research goal was to understand C storage in the forest floor and mineral soil and the major determinants. Relative to the northern forest (NF), the southern forest (SF) was found to produce higher amounts of litterfall (4.3 vs. 2.5 Mg·ha−1) and to store less C in the forest floor (~8 vs. ~12 Mg·ha−1) but more C in the mineral soil (~148 vs. ~72 Mg·ha−1). Newly-shed litter of NF had lower P (0.4 vs. 0.6 mg·g−1) but higher N concentration (13 vs. 10 mg·g−1) than SF. Despite its lower Mn concentration (0.06 vs. 0.18 mg·g−1), SF litter produces a Mn-richer humus (0.32 vs. 0.16 mg·g−1) that is less stable. The data suggest that decomposition in the NF forest floor is limited by the shorter growing season (178 days vs. 238 days) and the higher N concentrations in newly shed litter and forest floor. Differences in C stock in the mineral soil reflect differences in ecosystem productivity and long-term organic-matter accumulation. The vertical gradient of soluble and microbial fractions in the soil profile of SF was consistent with a faster turnover of organic matter in the forest floor and greater C accumulation in mineral soil relative to NF. With reference to regional-scale estimates from Italian National Forest Inventory data, the C stock in the mineral soil and the basal area of Italian beech forests were found to be significantly related, whereas C stock in the forest floor and C stock in the mineral soil were not

High Nature Value Farmland: Assessment of Soil Organic Carbon in Europe

High Nature Value Farmland (HNVF) is commonly associated with low intensity agricultural systems. HNVFs cover ~32% of the agricultural land in Europe and are of strategic importance for the European Union policy since they are reservoirs of biodiversity and provide several ecosystem services. Carbon sequestration is an important service that can be supplied by HNVFs as addressed in this study. Considering soil carbon content as a proxy for soil carbon storage, we compare HNVFs with soils that undergo more conventional land management (nHNVFs) and study the consequences of diverse land uses and geographic regions as additional explanatory variables. The results of our research show that, at the European level, organic carbon content is higher in HNVF than in nHNVF. However, this difference is strongly affected by the type of land use and the geographic region. Rather than seeing HNVF and nHNVF as two sharply distinct categories, as for carbon storage potential, we provide indications that the interplay between soil type (HNVF or nHNVF), land use, and geographic region determines carbon content in soils