Soil Microarthropod Biodiversity Research Articles

Effects of Land-Use Change on Soil Functionality and Biodiversity: Toward Sustainable Planning of New Vineyards

Sustainable agriculture largely depends on soil biodiversity and requires efficient methods to assess the effectiveness of agronomic planning. Knowledge of the landscape and relative pedosite is enriched by data on the soil microarthropod community, which represent useful bio-indicators for early soil-quality detection in land-use change (LUC). In the hilly Maremma region of Grosseto, Italy, two areas, a >10ys meadow converted into a vineyard and an old biodynamic vineyard (no-LUC), were selected for evaluating the LUC effect. For maintaining soil vitality and ecosystem services by meadow, the vineyard was planted and cultivated using criteria of the patented “Corino method”. The aim was to evaluate the LUC impact, within one year, by assessing parameters characterizing soil properties and soil microarthropod communities after the vineyard was planted. The adopted preservative method in the new vineyards did not show a detrimental impact on the biodiversity of soil microarthropods, and in particular, additional mulching contributed to a quick recovery from soil stress due to working the plantation. In the short term, the adopted agricultural context confirmed that the targeted objectives preserved the soil quality and functionality.

Early colonization of constructed technosol by microarthropods

Technosols are defined by the World Reference Base as soils subjected to a strong human influence and containing at least 20% of artefacts. The construction of Technosol using recycled waste material is considered an appealing sustainable use of both natural and anthropic resources. Constructed Technosol can attract and host a multitude of soil organisms, forming a reserve of biodiversity. In this study, we assessed the early colonization – in successional stages – of a constructed Technosol supporting grassland vegetation by the microarthropod community, in particular Collembola. To do this, the taxonomic and functional characteristics of microarthropod communities in a newly constructed Technosol in northeast France were studied for a period of four years. Collembola communities also increased in density and taxonomic richness, as well as in functional richness and dispersion. However, hemiedaphic Collembola dominated the community, particularly in the fourth year. Findings at the end of the survey indicated that the Collembola community in the studied Technosol remained very different to that of natural grassland, while it shared some characteristics with arable land. However, the present research clearly showed that waste material recycling to construct a Technosol could be an opportunity to support soil microarthropod biodiversity.

Recovery in soil cover and vegetation structure after ancient landslide in mountain fens under Caltho-Alnetum community and response of soil microarthropods (Hexapoda: Collembola) to natural restoration process

PurposeThe objective of this study was to determine the long-term environmental changes induced by ancient landslide in the mountain fen. Attempts were made to demonstrate the progress of the soil cover restoration process about 200 years after the landslides and associated with changes in vegetation and soil microarthropod biodiversity and occurrence pattern associated with the restoration of soil cover.Material and methodsThe study covered mountain fen of the Caltho-Alnetum in the Babiogórski National Park in Outer Flysch Carpathians, Poland, where ancient landslide deposits are causing disturbance in fen hydrologic regime and over time related to various rate of fen area natural restoration processes. The drill test has been used to assess changes in layering and thickness of the fen soils. The following soil parameters, such as pH and total organic carbon content, were determined at each distinguish layer. The diversity and distribution pattern of soil microarthropods, represented by Collembola, was examined in two parts of the fen: restored and not-restored. The soil parameters, such as pH, electrical conductivity, total exchangeable base, total organic carbon, and nitrogen content, were determined in the soil samples simultaneously. The assessment of the vegetation structure recovery within studied mountain fen after landslide was referred to average parameters of the community completed for other natural mountain fens under the Caltho-Alnetum community. The research results were statistically verified.Results and discussionThe test drillings showed that landslides change soil layering, site-specific soil properties of mountain fen such as chemistry (the statistically significant differences were noted only in the case of total organic carbon content), vegetation structure, and soil microarthropod communities. By changing site-specific conditions, landslides influence on the biodiversity and peatland ecosystems functioning.ConclusionOur results clearly demonstrate that the landslide itself initiated a complex and lengthy process of changes in biological aspects of peatlands including the biodiversity of the underground fauna and plant community. Soil microarthropod communities represented by Collembola can be used as a good indicator of mountain fen restoration process.

Belowground biota responses to maize biochar addition to the soil of a Mediterranean vineyard

Biochar is a high carbon material resulting from biomass pyrolysis that, when applied to croplands, can increase soil carbon and soil water retention. Both effects are of critical importance in semi-arid regions, where carbon decline and desertification are the main drivers of soil degradation. Since most environmental services provided by soil are mediated by belowground biota, effects of biochar on soil microbial and invertebrate communities must be evaluated under field conditions before its agricultural application can be recommended. We tested maize biochar for its mid-term effect on soil microbes and micro-arthropods of a Mediterranean vineyard. We applied biochar to three field plots with neutral sandy loam soils at a dose of 5 Mg ha−1. During two years, we monitored the abundance of functional groups of soil micro-arthropods and estimated the biomass of soil microbial groups. We also analyzed the δ13C value of microbial PLFA biomarkers to determine biochar-C utilization by each microbial group taking advantage of the δ13C natural abundance differences between the applied biochar and the soil. Biochar addition significantly reduced soil microbial biomass but did not alter the functional microbial diversity nor the abundance or biodiversity of soil micro-arthropods. The contribution of biochar-C to the diet of most microbial groups was very low through the monitoring period. However, two gram-negative bacterial groups increased their biochar-derived carbon uptake under extreme soil dryness, which suggests that biochar-C might help soil microbes to overcome the food shortage caused by drought. The decrease in microbial biomass observed in our experiment and the concomitant decrease of SOM mineralization could contribute to the carbon sequestration potential of Mediterranean soils after biochar addition.

Urban and industrial land uses have a higher soil biological quality than expected from physicochemical quality

Despite their importance both in soil functioning and as soil indicators, the response of microarthropods to various land uses is still unclear. The aim of this study is to assess the effect of land use on microarthropod diversity and determine whether a soil's biological quality follows the same physicochemical quality-based gradient from forest, agriculture-grassland, agriculture-arable land, vineyards, urban vegetable gardens to urban, industrial, traffic, mining and military areas. A database compiling the characteristics of 758 communities has been established. We calculated Collembola community indices including: species richness, Pielou's evenness index, collembolan life forms, the abundance of Collembola and of Acari, the Acari/Collembola abundance ratio, and the Collembolan ecomorphological index. Results show that agricultural land use was the most harmful for soil microarthropod biodiversity, whilst urban and industrial land uses give the same level of soil biological quality as forests do. Furthermore, differences between the proportions of Acari and ecomorphological groups were observed between land uses. This study, defining soil microarthropod diversity baselines for current land uses, should therefore help in managing and preserving soil microarthropod biodiversity, especially by supporting the preservation of soil quality.

Compaction by a forest machine affects soil quality and Quercus robur L. seedling performance in an experimental field

In recent decades, the use of heavy machinery in forest management has significantly increased, causing the compaction of forest soils and potentially affecting seedling survival and establishment. We thus investigated the effects of soil compaction on soil physical parameters, microarthropod biodiversity, soil respiration, as well as growth and physiology of Pedunculated Oak (Quercus robur) seedlings in an experimental field in central Italy (coarse loamy soil). Two levels of soil compaction were simulated, i.e. 10 tractor passes vs. 25 tractor passes. The larger number of tractor passes increased soil bulk density (+27%) and penetration resistance (+46%), while porosity declined (−11%). Compaction decreased the qualitative biodiversity of soil microarthropods (−13%), the number of growth flushes (−22%) and of leaves (−22%), shoot biomass (−26%), the shoot/root ratio (−10%), the main root length (−24%) and the longest first-order later root length in the top 10cm of soil (−31%). The decreased growth of seedlings in the soil compaction treatment was accompanied by lower photosynthetic rate (−34%) and leaf nitrogen content (−27%). We concluded that limited access and acquisition of nutrients and water due to the shorter length of main root likely played a key role for growth and physiological responses to soil compaction in Q. robur seedlings.

Effects of Cushion Plants on High-Altitude Soil Microarthropod Communities: Cushions Increase Abundance and Diversity of Mites (Acari), but not Springtails (Collembola)

ABSTRACTCushion plants in alpine ecosystems act as nurse species, which modify and alleviate environmental conditions and positively influence the diversity and abundance of other organisms. Soil fauna in alpine environments should benefit from nurse plant facilitation, but this has not been investigated. We compared diversity, abundance, and community structure of soil microarthropods (Collembola, Oribatida, Mesostigmata, Prostigmata, Endeostigmata, and Astigmata) under cushion plants and in adjacent open microsites in high altitude patterned ground landscapes in New Zealand. We investigated how cushion plants influence environmental factors, and how environmental factors and species traits contribute to microarthropod community structure. The results show that cushion plants are a key in maintaining the biodiversity of soil microarthropods in the high alpine. Cushion plants maintain higher moisture and organic matter content in the soil, provide productive and structurally complex habitat, and mitigate disturbance. Abundance and species richness of Oribatida, Mesostigmata, and Prostigmata were higher under cushion plants. In contrast, abundance of Collembola was higher in open microsites, while their species richness similar in and out of cushions. Oribatida assemblages were dominated by small asexual species, indicating a disturbed environment. Oribatida community structure was significantly related to the microhabitat in two out of three mountain ranges. Collembola assemblages were similar in and out of cushions. Higher soil moisture and organic matter content under cushion plants were significant in explaining patterns in microarthropod assemblages, although high percentage of variability was not explained by environmental variables. There was no effect of cushions on soil temperatures. Species identity of the cushion plant did not influence abundance, species richness, or community assemblages of mites and springtails; however, some species were associated with either Dracophyllum or Raoulia cushions.

Effects of the Conversion of Native Vegetation to Farmlands on Soil Microarthropod Biodiversity and Ecosystem Functioning in a Desert Oasis

Increased demand for food due to the rapidly growing human population has led to extensive conversion of native steppes at the margins of oases in arid lands of northwest China into intensively managed farmlands. However, the consequences of this land-use change for soil microarthropod biodiversity and ecosystem functioning remain unknown. Here we assessed how conversion of a native steppe to irrigated farmlands of different ages affects the abundance and composition of soil microarthropods and how changes in soil microarthropod biodiversity could scale up to influence soil carbon and nitrogen stocks. We sampled microarthropod communities over two growing seasons from native steppes and cultivated soils of a 27year-old irrigated farmland and a 90-year-old irrigated farmland, both of which were converted from the native steppe. Topsoil properties and bulk and labile pools of carbon and nitrogen, including soil organic carbon, dissolved organic carbon (DOC), microbial biomass carbon (MBC), total nitrogen (TN), inorganic nitrogen (IN), and microbial biomass nitrogen (MBN), were also measured. The conversion of native steppe to either of the two farmlands significantly increased the abundance and taxa richness of three taxonomic groups (mites, collembolans, and others) and four trophic groups (herbivores, predators, detritivores, and fungivores); this effect was greater in the 90-year-old farmland for the abundance of all taxonomic and trophic groups except for herbivores and was similar between the two farmlands for the richness of all taxonomic and trophic groups. Taxonomic and trophic composition of the microarthropod community showed strong shifts in response to conversion of native steppe to either of the two farmlands. Compositional changes were largely mediated by changes in soil environments. Changes

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 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.

Studies on the Biodiversity of Soil Microarthropods and Their Responses to Crude Oil Spills

Studies on the Biodiversity of Soil Microarthropods and Their Responses to Crude Oil Spills

Abundance and biodiversity of soil microarthropods as influenced by different types of organic manure in a long-term field experiment in Central Spain

We studied the effects of long-term organic and mineral fertilization on soil microarthropods and soil chemical parameters in a field experiment under semi-arid conditions in Central Spain. Two different regimes of organic manuring, i.e. farmyard manure applied once in 3 years versus annual manuring with crop residues were compared. Soil carbon and nitrogen contents were increased markedly by farmyard manure, whereas straw and green manure had no significant effect. In contrast, the abundance of soil microarthropods was increased by annual application of straw and green manure, but not by farmyard manure last applied 2.5 years before sampling. We conclude that in the field experiment under study the abundance of soil microarthropods was influenced by the immediate food supply rather than by soil chemical parameters, such as carbon and nitrogen content or the pH. Biodiversity of soil microarthropods, as estimated by the Shannon index, was not affected significantly by straw and green manure. Obviously, other management practices, especially tillage, are limiting the species composition of soil microarthropods and thereby overshadow possible effects of fertilization on diversity.

Soil biodiversity: myth, reality or conning?

The study of soil microarthropod biodiversity is illustrative of problems that are related to other soil organisms (fungi, for instance) or that can be found in other environments (canopy, oceanic sediments, hosts accommodating parasites, etc.). Indeed, the contribution of the soil fauna to global biodiversity remains an enigma even though, in recent years, it has received considerable attention. Our contention is that the debate on soil biodiversity will remain open – and even sterile – as long as adequate sampling methodologies are not set up, critically evaluated and largely used. First, a critical review of the sampling strategies used for soil microarthropods is presented. In addition to an extensive compilation of publications on extraction method efficiency, articles from two journals devoted to soil biology are compared for two five‐year periods (before and after Erwin's papers and before and after Rio). The most frequently used extraction methods (over 90% of studies) have a poor numerical efficiency (e.g. 7–26% for the Berlese‐Tullgren funnels) and also are selective with respect to their efficiency for certain taxa (variable taxonomic and functional efficiency), 75% of studies are restricted to the upper 10 cm of soil and therefore overlook largely the microarthropod populations, some groups are often neglected, however diversified they are, and the taxonomic resolution tends to become impoverished in recent years. In the second part of our study, the importance of bias induced by inadequate or restricted sampling strategies on biodiversity estimates is evaluated: densities are dramatically underestimated (down to 14 times less); conversely species aggregation, a factor advocated to explain the existence of numerous soil species, is overestimated; some functional groups may be quite overlooked; the species distribution along a gradient deduced from the sampling may be rather different from that really existing in the soil and interfere with the evaluation of β‐diversity; species richness is often crudely underestimated (down to 50%). Overall, at most 10% of soil microarthropod populations have been explored and 10% of species described. Obviously, much has still to be done to evaluate soil microarthropod biodiversity andafortioriunderstand the mechanisms underlying it. Improving and renewing the soil sampling strategy is thus a prerequisite to any real advance in our knowledge of this fascinating and obscure domain.

Biodiversity of soil microarthropods: the filtering of species

Decline of soil microarthropod biodiversity is described in the sequence: old forest stands, low-input grasslands, high-input grasslands (with and without the use of persistent pesticides). With this expected trend of declining biodiversity, the patterns of species losses are analysed with the use of classifications of life-history tactics, feeding guilds and tolerances to drought. Species intolerant to drought are absent in grasslands, but present in old forest stands. Also the fraction of thelytokously reproducing microarthropods is higher in old forest stands compared with low-input grasslands. The main difference between low-input and high-input grasslands is found in the feeding guild structure of the community. Low-input grasslands are dominated by (herbo-) fungivorous grazers, whereas high-input grasslands are dominated by fungivorous browsers. Application of DDT in high-input grasslands shows a high density of microarthropods with a high fraction of thelytokous reproduction, associated with a decrease in genetic variation in a thelytokously reproducing species. Patterns in species losses, the species filters, are explained and discussed. It is shown that the decline of biodiversity is not a randorn loss of species but follows and identifiable pattern.