Groups Of Soil Fauna Research Articles

Composition of the soil fauna community and leaf litter stock in agro-forestry systems and secondary forestry

Agro-Forestry Systems (AFS), in addition to being a means of providing income, can be considered an alternative way of helping conserve biodiversity, both above and below ground. The aim of this study was to evaluate the accumulation of tree leaf litter and its nutrient content as well as the composition of fauna in the soil-litter layer in two Agro-Forestry Systems (AFS-1 and AFS-2), using as reference an area of secondary Forest (SF), in the Quilombola do Campinho da Independência community, Paraty, in the state of Rio de Janeiro (RJ), Brazil. The collection of accumulated leaf litter and soil-litter fauna was carried out from four sample points in each area and at two different seasons of the year, the rainy and the dry season. The leaf litter stock and its nutrient content (Ca, Mg, P, K and N) were measured. The extraction of fauna was carried out according to Tüllgren’s method, modifying the Berlese funnel. The stock of accumulated leaf litter differed between the two areas only in the rainy season; the amounts were smaller in AFS-2. In general, the Agro-Forestry Systems were very similar to the secondary forest in terms of levels and/or stock of nutrients in the majority of cases, at least in one of the seasons studied. The composition of the soil fauna groups in the Agro-Forestry System (AFS-1 and AFS-2) had a high degree of similarity to that found in the forest, and these systems mainly favour the populations of groups like Collembola and Formicidae.

Fauna edáfica e suas relações com atributos químicos, físicos e microbiológicos em Floresta de Araucária

A permanente cobertura vegetal do solo, em Florestas de Araucária, contribui na conservação de sua biodiversidade edáfica. O objetivo deste trabalho foi avaliar o potencial da fauna edáfica e das variáveis ambientais explicativas (físico-químicas e microbiológicas do solo) na discriminação de florestas com araucária nativa e reflorestada. Avaliaram-se florestas com Araucaria angustifolia nativa (NF) e reflorestada (RF) em três regiões distintas no estado de São Paulo, representando três repetições. Em cada área, 15 amostras de solo foram coletadas para avaliação dos atributos físicos, químicos e microbiológicos e, nos mesmos pontos, procedeu-se às coletas da fauna utilizando-se o método de armadilhas de queda (Pitfall traps). A fauna do solo foi influenciada pela sazonalidade, apresentando maior abundância de indivíduos no verão. Os grupos Collembola, Formicidae e Coleoptera foram os mais abundantes, independentemente da época de amostragem e tipo de floresta. A Análise de Componentes Principais (ACP) e Análise Canônica Discriminante (ACD) claramente diferenciaram as áreas de araucárias. Na ACP, Hemiptera, Collembola e Diplopoda ficaram associados à RF no inverno, principalmente pelos maiores valores de matéria seca da serapilheira. Já em NF, foram os grupos Orthoptera, Hymenoptera, Araneae e Coleoptera, explicados pela melhor qualidade do solo e da serapilheira. No verão, ficaram associados à NF, os grupos Formicidae, Hemiptera, Orthoptera, Araneae, Coleoptera e Collembola, explicados pelos maiores valores de CBM, Ca, P, C-org, macroporosidade e atividade de desidrogenase. Na ACD, a abundância de grupos taxonômicos foi o atributo da fauna edáfica mais importante para a discriminação das florestas. Da mesma forma, a umidade do solo, teor de P no solo, porosidade total e teor de S na serapilheira contribuíram na discriminação das florestas. A semelhança entre as áreas, em relação aos grupos da fauna edáfica, indica que está ocorrendo uma estabilidade das áreas reflorestadas comparável às nativas.

Soil fauna diversity at different stages of reed restoration in a lakeshore wetland at Lake Taihu, China

ABSTRACT Introduction: Wetland soil fauna support material cycling and restoration processes in wetland ecosystems. In our study, we observed variations in wetland soil fauna on the shores of Lake Taihu, China. We examined the relationships between fauna and major environmental factors, and looked at the short-and long-term changes in reed wetlands under restoration and in the natural reed lakeshore. Outcomes: We identified 93 groups of soil fauna in different wetlands and found significant differences in the lakeshore wetlands’ soil fauna assemblages, depending on the length of the restoration period. By analyzing the soil fauna community evenness, dominance, number of taxa, and diversity, we found minimal seasonal variation in the soil fauna community diversity and abundance. The abundance of soil fauna in the sites under restoration decreased with depth below the soil surface. The reed restoration was obvious in the succession of the soil fauna groups in the long-term site. Although the restoration had an overall positive long-term effect on the soil fauna communities, there were no obvious short-term changes in the number of individuals. Conclusion: The study explored various potential measures to restore soil fauna in the Lake Taihu wetland and developed a theoretical basis for restoring the lakeshore wetland ecosystem.

Do ecological corridors increase the abundance of soil fauna?

ABSTRACTEcological corridors are areas of natural vegetation that connect two or more separate habitat patches, surrounded by a non-habitat matrix. Soil fauna is important for sustainability, conservation and soil quality. Thus, in this study, we aimed to investigate the influence of corridors on the soil faunal community in crops near savannah vegetation areas by examining the effects on trophic, movement and taxonomic groups. We collected data during the dry and rainy seasons in two areas of biodynamic agriculture. Then, we calculated trophic, movement, taxonomic group abundance, total abundance, richness, equability and diversity. The taxa Acari, Chilopoda, Oligochaeta, Orthoptera and Psocoptera were the most abundant in cultivated areas with corridors during the rainy season, while the taxa Dermaptera, Diplura, Diptera, Collembola, Formicidae larva, Lepidoptera and Lepidoptera larva were more abundant in cultivated areas with corridors during the dry season. The trophic, movement, taxonomic group abundance, richness, equability and diversity were higher during the rainy season and were not related to corridor presence. Ecological corridors increased the abundance of some taxonomic groups of soil fauna in cultivated areas, thereby contributing to the maintenance of specific taxonomic groups, which provide important ecosystem services.

Soil restoration using compost-like-outputs and digestates from non-source-separated urban waste as organic amendments: Limitations and opportunities

Soil rehabilitation in the context of the restoration of quarries, dumping sites, or road slopes often requires the prior addition of organic amendments to improve the substrates used for Technosol construction. Bio-wastes coming from advanced Mechanical-Biological Treatment Plants, mainly compost-like-outputs (CLO) and digestates (DGT), are new and suitable sources of organic matter potentially useful as organic amendments for this purpose, in an approach clearly fulfilling the principles of circular economy. In order to assess the suitability of these materials, a complete physicochemical and biological evaluation was carried out, including an ecotoxicological evaluation to discard hazardous effects on key soil fauna groups. Field experiments were also carried out on several road slopes and a dumping site. The stability degree of organic matter and the impurities content could be restricting parameters for the use of CLO in soils. Low stability degree decreased plant development in the initial stages of restoration. Moreover, the high heterogeneity in terms of physicochemical parameters of the different CLOs assessed is a serious constraint to making generalizations about its use. In contrast, composition of DGTs was more stable between plants and batches, and presented low impurities and high N contents that make them more suitable for applying to soil and promoting plant development. Regarding the application rates, DGT application at 20 g kg−1 clearly improved plant growth after sowing, without compromising recruitment. However, application at 80 g kg−1 did not ameliorate seed germination and plant growth, in either CLO or DGT treatments, and increased N-leaching and toxicity risk to soil mesofauna in DGT amended Technosols.

How agroforestry systems influence soil fauna and their functions - a review

Agroforestry systems have enhanced diversity of cultivated plants compared to monocultures, and are expected to affect associated biodiversity. Despite a growing body of literature on the importance of soil fauna, the known effects of different agroforestry types on soil fauna communities and functions have not yet been synthesized. We scanned publications on soil fauna in agroforestry systems. Our aim was to give an overview of strengths and weaknesses of the existing data, in terms of spatial coverage and representation of diverse agroforestry types and soil fauna groups and functions. Our database includes sixty-seven articles, mostly focusing on tropical regions and perennial crop agroforestry systems. Soil macrofauna are the most studied fauna group. The most common question addressed is the comparison of the effect of land use types on communities. Effects on fauna abundance and diversity are mainly positive when agroforestry is compared to cropland, and neutral or negative when compared to forests. Few publications actually measure soil fauna functions, or characterize their interactions and evolution in time and space depending on system design and management. Further work on soil fauna in agroforestry should harness ecological theory and address questions of spatial structure and scale, temporal dynamics and ecological interaction networks and how they determine ecosystem functioning.

Changes in the soil meso‐ and micro‐fauna community under the impacts of exotic Ambrosia artemisiifolia

AbstractSuccessful establishment of invasive plant species may exert important effects on soil organisms and processes. To investigate the response of the soil meso‐ and micro‐fauna community to Ambrosia artemisiifolia L. invasion and its age of colonization, samples were collected from three different depths in sites with and without the presence of A. artemisiifolia during the period of October, 2009 to July, 2010. Soil fauna were grouped into four categories, that is, Nematoda, Acarina, Collembola and other meso‐ and micro‐fauna species. Seasonal changes in abundance and distribution patterns in relation to soil biochemical properties were then compared and examined. In general, invasion of A. artemisiifolia into native plants significantly increased the soil fauna densities, especially nematodes. Effects of invasion on soil fauna groups were seasonally variable with density peaking in autumn. Short‐term invasion of A. artemisiifolia could weaken accumulation of soil fauna groups in the top layer. Vertical distribution of soil meso‐ and micro‐fauna communities changed seasonally with the trend of remarkable upward migrations in the period from winter, summer to spring and autumn, though the degrees of upward migration in the invaded and noninvaded sites differed among the fauna groups. Responses of soil fauna communities may be associated with the enhancement of soil nutrient conditions and microbial activities in the presence of A. artemisiifolia. That is, the colonization of A. artemisiifolia, irrespective of colonization age, may exert an important influence on soil meso‐ and micro‐fauna community over time and thus may be beneficial to its successful colonization.

Roles of environmental and spatial factors in structuring assemblages of forest-floor Mesostigmata in the boreal region of Northern Alberta, Canada

ABSTRACTMesostigmatid mites (Arachnida: Parasitiformes) are a diverse, abundant group of soil predators; however, in comparison to some other groups of soil fauna (e.g. oribatid mites), little is known about environmental and spatial processes that influence local species richness and abundance. The main objective of our study was to identify factors strongly correlated with assemblages of Mesostigmata from boreal forests in northern Alberta, Canada. Soil and litter samples came from 62 sites with up to 4 samples per site (216 samples total), with a north–south range of ~800 km between sites. Environmental variables included ground cover type (e.g. moss, lichen, grass), disturbance intensity, precipitation, and temperature. From 3021 individual adult Mesostigmata, we identified 101 species/morphospecies from 21 families, the most species-rich being Ascidae, Zerconidae, and Digamasellidae. Redundancy analysis determined that the environmental variables that correlated most strongly with mite assemblages were precipitation, moss cover, and disturbance intensity. Spatial distance between sites had almost the same explanatory power, as environmental factors. Assemblages became more dissimilar with increasing spatial distance. This study showed the importance that particular environmental and spatial factors likely have on Mesostigmata composition in Canadian boreal forests; however, manipulative studies are required to be able to attribute causation to these correlations.

A Red List of mites from the suborder Uropodina (Acari: Parasitiformes) in Poland

This article presents a Red List of mite species from the suborder Uropodina (Acari: Parasitiformes) occurring in Poland. Evaluation of the conservation status of the analyzed species was compiled on the basis of new criteria, which may also be applied to other groups of soil fauna. The authors employ the names of categories proposed by the International Union for Conservation of Nature (IUCN). One of our aims was to review the IUCN criteria to ascertain whether they are applicable in an attempt to assess the danger of extinction of soil invertebrates, and to see whether the criteria can be adapted to make such an assessment. The analyzed material contained 93 mite species obtained from 16,921 soil samples, which were collected between 1961 and 2017 in the whole area of Poland. The categories were assigned to species on the basis of the frequency of the species, but also other factors were taken into account, such as microhabitat specificity, vulnerability to detrimental conditions, and shrinking of local populations. One of the analyzed species can now be regarded as extinct, over 25% of the species (26 spp.) were labeled as critically endangered, and most of them (33 spp.) were categorized as vulnerable—the other species were assigned to the categories endangered (13 spp.), near threatened (10 spp.), and least concern (10 spp.).

Diversity in form and function: Vertical distribution of soil fauna mediates multidimensional trait variation.

It has been widely recognized that species show extensive variation in form and function. Based on species' attributes, they can be positioned along major axes of variation, which are often defined by life-history traits, such as number of offspring, age at maturity or generation time. Less emphasis has been given in this respect to tolerance traits, especially to resistance to abiotic stress conditions, which often determine community (dis)assembly and distribution. Soil fauna species distribution is governed to a large extent by environmental conditions that filter communities according to functional traits, such as abiotic stress tolerance, morphology and body size. Trait-based approaches have been successfully used to predict soil biota responses to abiotic stress. It remains unclear, though, how these traits relate to life-history traits that determine individual performance, that is, reproduction and survival. Here, we analyse patterns in multidimensional trait distribution of dominant groups of soil fauna, that is, Isopoda, Gastropoda and Collembola, known to be important to the functioning of ecosystems. We compiled trait information from existing literature, trait databases and supplementary measurements. We looked for common patterns in major axes of trait variation and tested if vertical distribution of species in the soil explained trait variation based on three components of trait diversity (trait richness, evenness and divergence). Our results showed that two to three axes of variation structured the trait space of life-history and tolerance traits in each of the taxonomic groups and that vertical distribution in soil explained the main axis of trait variation. We also found evidence of environmental filtering on soil fauna along the vertical soil distribution, with lower trait richness and trait divergence in soil-dwelling than in surface-living species. Our study was partially limited by the lack of detailed trait measurements for the selected taxonomic groups. In this regard, there is an urgent need for standardized trait databases across invertebrate groups to improve trait-based diversity analysis and fill gaps in the mechanistic understanding behind trait distribution, trait filtering and the link with species fitness and performance.

Composition and structure of soil fauna community in the Dexing Copper Mine tailings pool after revegetation

The Dexing Copper Mine is one of the largest copper mines in Asia, but few studies have reported the soil fauna community composition after revegetation. This study investigated the influence of revegetation on the soil fauna communities and structures in three vegetation restoration models (designated as I, II, and III) and in a sample without revegetation (IV) in two tailings pools of Dexing Copper Mines 1 and 2 using modified Tullgren and Baermann methods. A total of 548 individuals were collected, which belonged to 5 classes, 7 orders, 3 suborders, and 19 families. The individuals, groups, and diversity of the soil fauna were significantly affected by the vegetation restoration model. In comparison to the sample without revegetation, the samples with revegetation showed a significant increase in the number of individuals and groups of soil fauna (P < 0.01) and significantly increased functional groups of the soil fauna community (P < 0.05). The number of individuals and groups of soil fauna were the highest in sample III, which was planted with trees and covered with guest soil, and the functional groups of the soil fauna community were the highest in samples II and III, which were both covered with guest soil. In principal component analysis, a significant difference was detected in the communities of soil fauna after revegetation, and the structures of soil fauna communities were similar in samples I and IV, which were not covered with guest soil. The number of individuals and groups of soil fauna was closely related to the revegetation in the Dexing Copper Mine tailings pool. These results should help in improved handling of the environmental issues associated with mines.

Effects of naphthalene on soil respiration, dissolved organic matter and microbial biomass in the subalpine forest of western Sichuan, China

The effects of naphthalene on soil respiration, dissolved organic matter and microbial biomass, and its inhibition efficiency for soil fauna of subalpine forest in western Sichuan were studied by in situ control experiment. The results showed that naphthalene application significantly inhibited the individual density and group number of soil macro- and meso-/micro- arthropods, with the individual density being decreased by 76.3%-78.5% and 83.3%-84.8% respectively, and the number of groups being decreased by 48.3%-56.1% and 45.8%-58.3%, respectively. The seasonal dynamics of soil respiration rate showed single peak curves in both naphthalene treatment and control. The lowest and the highest soil respiration rates were observed in February and August, respectively. The naphthalene treatment had little effect on soil respiration. Compared with the control, naphthalene treatment significantly reduced the contents of soil dissolved carbon and dissolved nitrogen in August and October as well as microbial biomass carbon (MBC) in April and August, but increased MBC/MBN in April. The naphthalene treatment and sampling time significantly interacted to affect the MBC and MBN, but had no significant effect on individual density, the number of groups of soil fauna and DC content. In all, naphthalene as biocide could effectively inhibit the soil arthropods and had no significant effect on soil respiration, but it had varying degrees of effects on soil carbon and nitrogen components in subalpine forest of western Sichuan.

基于Meta分析的中国西南喀斯特地区土壤动物群落特征研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于Meta分析的中国西南喀斯特地区土壤动物群落特征研究 DOI: 10.5846/stxb201611282434 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 贵州省教育厅项目（黔教合KY字[2016]001） Characteristics of soil fauna communities in the Karst region, Southwest China, based on meta-analysis Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:我国西南喀斯特地区环境容量小、生态系统变异敏感度高、灾变承受能力低，是典型的生态环境脆弱区。土壤动物是陆地生态系统的重要组成部分，对生态系统功能和稳定性具有重要的意义。通过Meta分析研究西南喀斯特地区土壤动物群落特征，得到如下结果：本区域土壤动物隶属于5门15纲31类；中小型土壤动物平均密度6.0×103-1.9×104 m-2；中小型土壤动物密度和类群数表现为夏秋高、冬春低，土壤动物表聚性明显；喀斯特石漠化显著降低中小型土壤动物的密度和类群数量。本研究的结果表明，我国西南喀斯特地区土壤动物类群数量较为丰富，个体密度较低但可能被低估。在今后喀斯特地区生物多样性保护和脆弱生态系统的恢复工作中，应注重土壤动物群落的相关研究。 Abstract:The karst area in Southwestern China is regarded as one of the most vulnerable ecological zones, characterized by low environmental capacity, high sensitivity of environmental variation, and low resilience of ecosystems to catastrophic variations. Soil fauna are important components of terrestrial ecosystems and play significant roles in maintaining the functions and stability of ecosystems. Based on meta-analysis, the present study evaluated the community characteristics of soil fauna in the Karst region, Southwest China, by analyzing the soil fauna species composition, their vertical distribution, and the influence of rocky desertification on soil fauna density and group numbers. Publications related to studies of soil fauna ecology studies carried out in the Karst region of Southwest China, which were published between January 1, 1990 to October 31, 2016, were retrieved from the Web of Science and China Knowledge Resource Integrated Database (CNKI) by using key words of soil fauna, soil animal, soil invertebrates, soil micro-arthropods, and karst both in Chinese and English. A total of 34 publications were selected for meta-analysis after literature filtering and quality evaluation. Results of meta-analysis, using R langue for statistical analysis, showed that soil fauna belonged to 5 phyla, 15 classes, and 31 groups (classes or orders) in the Karst region of Southwest China. Soil macro-fauna were dominated by Hymenoptera and Coleoptera. Soil micro-fauna and soil meso-fauna were dominated by soil mites and collembolan. The density of soil micro-fauna and meso-fauna ranged from 6.0×103 to 1.9×104 individuals m-2. Soil fauna density and group numbers in summer and autumn were significantly higher than those in winter and spring. Rocky desertification in the Karst region, Southwest China, significantly decreased soil fauna density (P < 0.01, MD=-7799.6, 95% CI:-10822.24——4776.99) and group numbers (P < 0.01, MD=-1.9, 95% CI:-2.89——1.09). Soil fauna individuals significantly decreased with soil depth (P < 0.01, MD=-23.4, 95% CI:-0.31——0.16), showing an obvious phenomenon of soil surface layer accumulation. These results indicate that soil fauna group numbers were high, while the density was low. Nevertheless, soil fauna density was possibly underestimated because of the lack of soil nematodes data in most of the retrieved original publications. Because of the importance of soil fauna in ecosystems, greater attention should be paid to the soil fauna communities and their ecological functions, especially for biodiversity protection and the recovery of vulnerable ecosystems in the Karst region, Southwest China. 参考文献 相似文献 引证文献

Effects of soil fauna on leaf litter decomposition under different land uses in eastern coast of China

Soil fauna decompose litter, whereas land use changes may significantly alter the composition and structure of soil fauna assemblages. However, little is known of the effects of land-use on the contribution of soil fauna to litter decomposition. We studied the impacts of soil fauna on the decomposition of litter from poplar trees under three different land uses (i.e. poplar-crop integrated system, poplar plantation, and cropland), from December 2013 to December 2014, in a coastal area of Northern Jiangsu Province. We collected litter samples in litterbags with three mesh sizes (5, 1 and 0. 01 mm, respectively) to quantify the contribution of various soil fauna to the decomposition of poplar leaf litter. Litter decomposition rates differed significantly by land use and were highest in the cropland, intermediate in the poplar-crop integrated system, and lowest in the poplar plantation. Soil fauna in the poplar-crop integrated system was characterized by the highest numbers of taxa and individuals, and highest Margalef’s diversity, which suggested that agro-forestry ecosystems may support a greater quantity, distribution, and biodiversity of soil fauna than can single-species agriculture or plantation forestry. The individuals and groups of soil fauna in the macro-mesh litterbags were higher than in the meso-mesh litterbags under the same land use types. The average contribution rate of meso- and micro-fauna to litter decomposition was 18.46%, which was higher than the contribution rate of macro-fauna (3.31%). The percentage of remaining litter mass was inversely related to the density of the soil fauna (P < 0.05) in poplar plantations; however, was unrelated in the poplar-crop integrated system and cropland. This may have been the result of anthropogenic interference in poplar-crop integrated systems and croplands. Our study suggested that when land-use change alters vegetation types, it can affect species composition and the structure of soil fauna assemblages, which, in turn, affects litter decomposition.

Seasonal and annual variation in fungal communities associated with epigeic springtails (Collembola spp.) in boreal forests

Soil fauna mediate nutrient cycling through engineering physical properties and altering microbial communities in soil. Collembola is one of the most abundant groups of soil fauna, which regulates microbial communities by consumption and dispersal. The spatial structure of associations between Collembola and soil microbes have been described in several studies, but temporal variation of these associations remains unclear. Using high-throughput sequencing, we studied the fungal communities on Collembola (Entomobrya nivalis, Orchesella flavescens, Pogonognathellus longicornis) body surface, gut and their immediate habitat (topsoil samples) in four seasons across three years. The soil samples were characterized by fairly uniform relative abundance of saprotrophic and mycorrhizal fungi, whereas collembolans were associated mostly with saprotrophs. The structure of fungal communities from all substrate types exhibited comparable patterns of temporal distance decay of similarity. Unlike in soil, fungal richness and composition in Collembola body and gut samples exhibited seasonal and annual variation, with a significant interaction term, indicating low predictability. These results reflect spatial and temporal plasticity of the fungal communities associated with epigeic Collembola, indicating the high adaptability of collembolans to available conditions. We found that the Collembola associations with fungi (including diet) did not vary among the studied epigeic Collembola species. The detected high diversity of fungi associated with Collembola suggests that dispersal by arthropod vectors may represent a powerful alternative to aerial dispersal of fungal propagules.

Soil fauna community after removal of litter and herb layers in an artificial Phoebe zhennan plantation.

As a main component of soil ecosystems, soil fauna play an important role in the process of soil element cycling, transformation, and migration; however, soil fauna diversity is closely related to ground cover which has a tremendous impact on soil moisture and temperature. To reveal responses of the soil fauna community to the loss of the litter and herb layers, soil fauna in a Phoebe zhennan plantation on the western Sichuan Basin border were studied after litter and herb layers were removed. In each sampled area, soil animals were collected by hand, recorded, and put into a container with alcohol. Then they were transported to a laboratory for detailed classification and identification. The meso-and microfauna samples were gleaned by the steel core and stored in special soil fauna sealing bags. Next, all samples were transported to a laboratory within 12 h and were subsequently separated by both the Tullgren and Baermann methods over 48 h. Mesofauna were observed by microscope after 4 h to avoid autolysis of Enchytraeidae. All collected soil fauna were counted and classifiedunder a light microscope and were identified according to the reference of Pictorial keys to the soil animals of China. The experiments conducted in July and September, based on statistical analytical software SPSS and Excel, a density-group index (DG) was made. Results showed a collection of 4 phyla from 13 classes with 32 orders having 99 families comprising a total of 1 753 individual soil fauna. Also, after removal of the litter and herb layers, decreases in the soil fauna groups from the two experiments and the DG index in July were highly significant (P < 0.01). After a monthwith the liter and herb removals, compared with Control sites, the soil fauna average density decrease significantly (P < 0.01). Thus, the soil fauna community was deeply influenced by loss of the litter and herb layers, which revealed the relations between the underground biodiversity and the plant species.

Litter and soil-related variation in functional group abundances in cacao agroforests using structural equation modeling

The aim of this study was to apply the method of structural equation modeling using latent variables (constructs) with multi-indicators to test hypothesized interaction models among functional groups of fauna and attributes of litter-soil system in cacao agroforests in the south of Bahia, Brazil. The hypothesized structural model was composed of four constructs: the litter-attributes, litter-fauna, soil-attributes, and soil-fauna. The models tested were able to distinguish between the direct and indirect relationships of the faunal groups and attributes of litter-soil system. The results have shown that the interconnection theory between fauna and attributes of litter-soil system should be presented in more than one structural equation model. The models built from the re-specifications showed a strong theoretical base and data fitted, well representing the fauna as a latent variable (construct) theory within the litter-soil system of cacao agroforests. The overall fit of the hypothesized models highlighted the theoretical plausibility of complex interconnection between soil and litter fauna. Both are influenced by the attributes of their niches. Litter-attributes construct composed only by the indicators lignin, cellulose and polyphenols showed a recalcitrant predominant nature. This low litter nutritional quality would negatively affect the faunal groups therein. The negative relation between litter-attributes and soil-attributes suggest that low-quality litter contributed little to the improvement of soil fertility, particularly related to the level of acidity. The negative relationship between soil-attributes and soil-fauna shows that highly acid and low-fertility soils would promote some restriction on the activity of soil fauna groups. The structural equation modeling with latent variables proved to be a suitable tool for the understanding of the complexity of the relationships between faunal groups within the tested litter-soil system, indicating how the changes in a latent composition would affect other latents. It important to mention that when the approach is about organisms in the litter-soil system, caution is advised when trying, in a mechanistic way, to determine the factors influencing the interconnection of these organisms with their niches, due to the inherent heterogeneity of both litter and soil.

Interactions between earthworms and mesofauna affect CO2 and N2O emissions from soils under long-term conservation tillage

Soil carbon dioxide (CO2) and nitrous oxide (N2O) emissions contribute significantly to global warming. Studies have shown that soil fauna can significantly affect greenhouse gas emissions. To date, although there were some studies on the effect of interactions of soil fauna on soil CO2 and N2O emissions, the role of soil fauna on CO2 and N2O emissions is far from settled, especially for a wide variety of soil and human practices. Therefore, we studied how the interactions between different groups of soil fauna affect soil CO2 and N2O emissions from an arable black soil (Typic Hapludoll, USDA Soil Taxonomy) subjected to conservation tillage for 13years. We conducted a 35-day microcosm experiments with black arable soil and hay residues. The following soil fauna groups were included in our experiments: earthworms (Eisenia fetida (Savigny 1826)), Collembola (Thalassaphorura encarpata (Denis 1931) and Allonychiurus songi (Sun and Wu 2012)) and predatory mites (Hypoaspis kirinensis (Chang et al., 1963)). The presence of earthworm and Collembola significantly enhanced soil N2O emissions (P<0.01) but did not significantly affect CO2 emissions (16days later) (P>0.05). The addition of micro-size predator mites to microcosms did not enhance soil CO2 or N2O emissions. This suggests the presence of earthworms in microcosms can increase soil CO2 and N2O emissions. In addition, the effects of predators with different species and their interactions with other groups on soil properties should be considered. This study indicates that earthworm plays the dominant roles in soil CO2 and N2O emissions, especially with other soil mesofauna, such as Collembola. Also, our data analyses demonstrate that higher contents of available soil C and N can result in higher CO2 and N2O emissions.

Can changes in litter quality drive soil fauna structure and functions?

Crop residues restitution has significant impacts on soil biota, as it constitutes the main carbon (C) source in cultivated system, and differently alters belowground communities depending on its initial quality. However, functional consequences of such changes have mainly been studied considering few taxa, and less is known on the effects of biota differentiation in complex, un-manipulated communities. To evaluate the role of litters diverging qualities on soil fauna assemblages and functions during decomposition, we incorporated into the soil two litters of different qualities (high: pea or low: barley) in a long-term experimental research station studying the impacts of different cultural practices in Northern France. We measured initially and after 7 and 11 months the abundance and composition of main functional groups of soil fauna: bacterial-feeders, fungal-feeders, meso- and macro-detritivores. In parallel, we followed litter mass loss and quality, enzymatic activities (hydrolytic and oxidative), soil mineral N content, microbial and fungal biomass.Pea and barley litter qualities gradually diverged across time due to the faster depletion of cellulose in pea (−38%) than in barley (−18%), leading to contrasting enzymatic activities despite similar mass loss for both litters. Microbial-feeders exhibited more changes between the sampling dates rather than between the different litters. Contrastingly, detritivores (meso- and macro-) mirrored divergence in quality of pea and barley litters across time with increasing composition dissimilarities after 0, 7 and 11 months. As a consequence, enzymatic activities were better explained by detritivores rather than by microbial-feeders composition. These relationships suggested a direct link between the identity of the taxa stimulated and the nature of the top-down regulation during litter decomposition.

秸秆还田对耕作黑土中小型土壤动物群落的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 秸秆还田对耕作黑土中小型土壤动物群落的影响 DOI: 10.5846/stxb201511202350 作者: 作者单位: 哈尔滨师范大学地理科学学院,哈尔滨师范大学 地理科学学院,哈尔滨师范大学地理科学学院,哈尔滨师范大学地理科学学院,哈尔滨师范大学地理科学学院,哈尔滨师范大学地理科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41371072，41471037）；黑龙江省普通本科高等学校青年创新人才培养计划（UNPYSCT-2015054）；哈尔滨师范大学校青年学术骨干项目（10XQXG08） Effect of straw-returning management on meso-micro soil fauna in a cultivated black soil area Author: Affiliation: College of Geographical Science,Harbin Normal University,Key Laboratory of Ｒemote Sensing Monitoring of Geographic Environment,College of Heilongjiang Province,,,College of Geographical Science,Harbin Normal University,Key Laboratory of Ｒemote Sensing Monitoring of Geographic Environment,College of Heilongjiang Province,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了考察秸秆还田对耕作黑土中土壤动物群落结构的影响，2009年到2011年在黑龙江省海伦市进行了定点实验，调查了样地A（17 kg秸秆+含高浓度催腐剂还田）、样地B（8.5 kg秸秆+含低浓度催腐剂还田）、样地C（对照样地），样地D（8.5 kg秸秆还田），样地E（17 kg秸秆还田）的中小型土壤动物群落结构。共获取中小型土壤动物21779只，分别隶属于58个类群。其中，甲螨亚目、姬跳虫科、棘跳虫科与驼跳科4个类群土壤动物在本地区是最适应环境变化的土壤动物类群。土壤动物群落结构分析表明，对照样地C中土壤动物密度最高（46591.67只/m2），土壤动物类群最多（17.17），土壤动物优势度指数最大（0.37），样地D中土壤动物丰富度指数最多（2.63），样地A中土壤动物多样性指数最高（1.72），样地B中土壤动物均匀性最高（0.64）。同时，各样地土壤动物基本都具有表聚性，样地A中土壤动物更趋于生存于上层土壤。综合比较分析表明，样地A秸秆还田方式相对来说最利于土壤动物生存。主成分分析表明，不同秸秆还田方式对土壤动物密度、甲螨亚目动物类群、节跳虫科类群、前气门亚目类群影响较大，是耕作黑土中对秸秆还田方式反应敏感的土壤动物指标，今后可以作为考察耕作黑土秸秆还田肥力效应的评价指标。另外，CAA分析表明：受土壤环境因子影响较大的土壤动物类群多为研究区域内优势类群与常见类群，土壤动物的密度与土壤中有机质、有机碳、碳氮比与全磷的含量关系最为密切。 Abstract:Crop straw is an important material basis for nutrient cycling in agro-ecosystems. Straw returning is a method in which straw is applied to the soil to improve soil properties, and is used for accelerating immature soil development in cultivated land and improving soil fertility. Soil fauna is an important component of the ecosystem, and is involved in the straw decomposition process, improving the decomposition of organic matter and promoting nutrient absorption by plants. Therefore, research on the ecology of soil fauna and sustainable utilization of cultivated soil, including black soil, has been widely conducted. Understanding the correlation between soil fauna and straw returning will provide a scientific basis for the protection of the soil fauna community and sustainable utilization management of tillage ecosystems in black soil areas. To investigate the effect of straw returning on meso-micro soil fauna communities in cultivated black soil, field experiments were carried out in Hai-lun, Heilongjiang Province from 2009 to 2011. The experiments were conducted in five selected plots:Plot A:17 kg corn straw returning and high concentrations of microbial inoculants; Plot B:8.5 kg corn straw returning and low concentrations of microbial inoculants; Plot C:control; Plot D:8.5 kg corn straw returning; and Plot E:17 kg corn straw returning. A total of 21,779 individuals, belonging to 58 groups, were extracted and identified in the plots. Among them, Oribatida, Hypogastruridae, Onychiuridae, and Cyphoderidae were most suitable to understand environmental changes in the study area. Analysis of the soil fauna community structure showed that the density, group number, and Simpson Dominance Index of soil fauna were highest in the control Plot C (46,591.67 ind/m2, 17.17, 0.37, respectively). The soil fauna richness index was highest in Plot D (2.63); the diversity index was highest in Plot A (1.72); and the evenness index was highest in Plot B (0.64). Meanwhile, the soil fauna was characterized by surface accumulation in the experimental plots. The group numbers of dominant soil fauna in Plot A in all soil layers were lower than those in other plots, and soil fauna was more dominant in the upper layer of the soil. Together, the method of straw returning in Plot A was the most productive for soil fauna. In addition, the results of a Principal Component Analysis (PCA) indicated that different methods of straw returning had a considerable effect on soil fauna density. Oribatida, Isotomidae, and Prostigmata were sensitive soil fauna that responded to different methods of straw returning, and could therefore be considered as an evaluating index to investigate the fertility effect of straw returning in cultivated black soil in the future. The results of the Canonical Correspondence Analysis (CCA) indicated that the dominant and common groups of soil fauna were considerably influenced by the soil environment, and the density of soil fauna was closely associated with organic matter, organic carbon, the carbon to nitrogen ratio, and total phosphorus in the soil. 参考文献 相似文献 引证文献