Soil Fauna Communities Research Articles

Diversity of soil faunal community as influenced by crop straw combined with different synthetic fertilizers in upland purple soil

Soil fauna play a crucial role in sustaining agro-ecosystem functions. Crop straw is recommended for application to agricultural fields to improve soil quality. However, the effects of crop straw combined with different synthetic fertilizers on the soil faunal community remain unclear, and knowledge regarding purple soil is limited. Using the conserved cytochrome c oxidase I (COI) gene as markers, we examined the responses of the soil faunal community to different fertilization in upland purple soil of southwestern China. The accuracy of the morphological and molecular methods in characterizing soil nematodes was compared. Our results showed that different fertilization treatments significantly changed the soil faunal community structure (Adonis test, R2 = 0.43, P = 0.011). Sixteen biomarkers were identified according to LEfSe (linear discriminant analysis effect size). The diversity and species number of soil fauna were closely related to soil organic matter (SOM) and total phosphorus (TP) (P < 0.05). This study indicates that crop straw return can improve the soil fertility and diversity of soil fauna in purple soil. Additionally, the morphological approach and molecular method based on the COI gene can be considered as complementary approaches in characterizing soil nematode community.

Reducing tillage intensity benefits the soil micro‐ and mesofauna in a global meta‐analysis

AbstractSoil fauna drives crucial processes of energy and nutrient cycling in agricultural systems, and influences the quality of crops and pest incidence. Soil tillage is the most influential agricultural manipulation of soil structure, and has a profound influence on soil biology and its provision of ecosystem services. The objective of this study was to quantify through meta‐analyses the effects of reducing tillage intensity on density and diversity of soil micro‐ and mesofaunal communities, and how these effects vary among different pedoclimatic conditions and interact with concurrent management practices. We present the results of a global meta‐analysis of available literature data on the effects of different tillage intensities on taxonomic and functional groups of soil micro‐ and mesofauna. We collected paired observations (conventional vs. reduced forms of tillage/no‐tillage) from 133 studies across 33 countries. Our results show that reduced tillage intensity or no‐tillage increases the total density of springtails (+35%), mites (+23%), and enchytraeids (+37%) compared to more intense tillage methods. The meta‐analyses for different nematode feeding groups, life‐forms of springtails, and taxonomic mite groups showed higher densities under reduced forms of tillage compared to conventional tillage on omnivorous nematodes (+53%), epedaphic (+81%) and hemiedaphic (+84%) springtails, oribatid (+43%) and mesostigmatid (+57%) mites. Furthermore, the effects of reduced forms of tillage on soil micro‐ and mesofauna varied with depth, climate and soil texture, as well as with tillage method, tillage frequency, concurrent fertilisation, and herbicide application. Our findings suggest that reducing tillage intensity can have positive effects on the density of micro‐ and mesofaunal communities in areas subjected to long‐term intensive cultivation practices. Our results will be useful to support decision making on the management of soil faunal communities and will facilitate modelling efforts of soil biology in global agroecosystems.HIGHLIGHTSGlobal meta‐analysis to estimate the effect of reducing tillage intensity on micro‐ and mesofaunaReduced tillage or no‐tillage has positive effects on springtail, mite and enchytraeid densityEffects vary among nematode feeding groups, springtail life forms and mite subordersEffects vary with texture, climate and depth and depend on the tillage method and frequency

Soil Environment and Fauna Communities in Europe after Afforestation of Post-Agricultural Lands—A Review

Afforestation can make an important contribution mitigating the effects of changing climate and provide structural and functional benefits. Afforestation also provides challenges for forest managers connected with past land-use history; therefore, there is an urgent need to summarize knowledge about such habitats and point out the gaps in knowledge for planning future studies. Although post-agricultural forests cover a large forest area in Europe, our understanding of the mechanisms governing the below-ground environment is still poor, especially when soil fauna is considered. In this study, we revised knowledge about the soil environment and the response of soil fauna to afforestation on former agricultural lands located in Europe based on research articles from the ISI Web of Science database. Data came from various but distinct locations, compared forests with different types of agricultural lands, and presented previous knowledge about soil chemistry and accompanying soil fauna communities. Finally, we selected 15 studies, investigating soil fauna communities on post-agricultural lands. The meta-analysis was based on response ratio (R) for available data, although in many cases the data were incomplete. Results indicated that post-agricultural forests differ from arable lands in reference to soil pH, but not for soil organic matter and carbon content. Different soil animal groups were represented by a similar number of studies: microfauna (seven studies) and mesofauna (nine), whereas macrofauna were represented by five studies. Meta-analysis revealed that the response of soil fauna to afforestation differed between soil fauna size classes. Additionally, in total, 18 tree species, 12 soil types, and 20 soil parameters were provided in the literature but only a few of them were presented in a single study. Future studies should include the impact of microclimate, detailed stand characteristics and soil conditions, which could help to clearly describe the impact of certain tree species growing on certain soil types. In future soil fauna ecological studies, the data should include mean values, standard deviation (SD) and/or standard effort of means (SE) for abundance, species richness, diversity indices and number of collected samples. Providing the above mentioned information will give the broad audience the opportunity to include data in future comparative analyses.

Differential responses of soil arthropods to the application of biogas slurry and biochar in a coastal poplar plantation

As critical drivers of ecosystem functionality, soil fauna are sensitive to soil management such as organic amendments. However, the effects of organic amendments on soil fauna communities are poorly understood. Here, we evaluated the differentiated responses of soil arthropod communities to the application of biogas slurry (BS) and biochar (BC) in a newly established poplar plantation on reclaimed coastal land. Compared with the control, the application of BS increased the abundance of soil arthropods by 113–253%, whereas the application of BC decreased it by 35–74%. Furthermore, the total taxonomic richness and Shannon index of the soil arthropods increased under the BS treatments and decreased under a high-dose BC treatment. Arthropod abundance and diversity under the BS treatments correlated with the increased biomass (46–76%) of leaf litterfall, fine roots, and undergrowth vegetation, elevated soil water and nitrogen concentrations (28–254%), as well as neutralized soil pH. In contrast, arthropod abundance and diversity under the BC treatments were correlated with decreased fine root biomass and increased soil alkalinity. These results suggested that BS and BC applications exert different effects on arthropod communities, probably linked with the differential direction and extent of the modification on plant food resource and soil variables in the newly reclaimed coastal lands.

Land use and soil properties shifts soil fauna community complexity in subtropical ecosystems

ABSTRACT The degraded areas in Southern Brazil are undergoing rapid conversion from abandoned fields into agroforestry system. Our focus was to investigate the impact of land use and soil properties on soil fauna and quality in an agroforestry system and a natural ecosystem. The agroforestry system had the presence of Cicadidae (0.1 ind trap−1), Diplura (0.01 ind trap−1), Gryllidae (0.2 ind trap−1), Gyrinidae (0.07 ind trap−1), and Larvae (0.3 ind trap−1), and it presents lower SOC (less 44.3%) and higher total N (more 29.8%) and P contents (more 68.8%) when compared with the natural ecosystem. Richness and diversity declined (less than 16.3 and 31.8%, respectively) with increasing soil pH. Natural ecosystem showed the greatest diversity (H’ = 2.44) of soil fauna. A negative correlation was observed between diversity and soil pH (−0.91), and positive correlations among diversity and SOC (0.97), richness (0.88), and dominance (0.93). In conclusion, fauna abundance, precipitation, and soil pH played essential roles in soil quality through ecosystem services, habitat, and energy provision, which in turn promoted the entire soil food web. Thus, the findings in the agroforestry system and natural ecosystem help us to understand how land uses impact soil fauna, and soil quality.

Soil meso- and micro-fauna community in response to bamboo-fungus agroforestry management

Bamboo-fungus agroforestry management is an ecological model of sustainable production of moso bamboo forest, and Stropharia rugosoannulata has been widely planted in moso bamboo forest. However, little attention has been paid to soil fauna community in bamboo-fungus agroforestry system. Thus, the aim of this study was to investigate the response of soil fauna communities to agroforestry management, and to explore the relationships between soil fauna communities and soil properties. An experiment with 0, 1, 2 and 3 years of planting was carried out in an existing moso bamboo forest. The community composition of soil meso- and micro-fauna was investigated, and the soil properties were determined. Results showed that a total of 2968 individuals of soil meso- and micro-fauna, belonging to 8 classes and 13 groups were detected. The group number and density of soil fauna was highest right and then decreased. Planting Stropharia rugosoannulata in moso bamboo forest increased the density of dominant groups, but did not change its composition. Shannon-Weiner diversity index (H), Margalef richness index (D) and Density-Group diversity index (DG) were the highest one year after planting the fungus, while Simpson dominance index (C) was the lowest in the meantime. Contents of soil moisture (SMC), organic matter (SOM), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) increased first and then decreased with the increase of planting years, peaking at 1 year after planting, while the pH value continued to increase. Responses of soil fauna community were associated with soil physicochemical properties. Redundancy analysis (RDA) showed that SOM was the main environmental factor driving the variation of soil fauna community, followed by TP and TN. In conclusion, planting Stropharia rugosoannulata in moso bamboo increased the diversity and abundance of soil fauna communities due to its contribution to abundance of organic matter and supply of nutrients.

Positive Effects of Reforestation on the Diversity and Abundance of Soil Fauna in a Landscape Degraded Red Soil Area in Subtropical China

Serious soil degradation due to human intervention in subtropical China has resulted in a series of ecological problems. Soil fauna is an important part of forest soil ecosystems and plays a vital role in the maintenance of soil quality and can sensitively reflect the soil disturbances caused by human activities. This study assessed the long-term effects of reforestation on the soil fauna community and underground food web. Soil fauna was sampled from plots in a 30-year reforestation positioning test site. Six reforestation models (the pure Schima superba (Ss) forest, pure Liquidambar formosana (Lf) forest, pure Pinus massoniana (Pm) forest, mixed forest of Lf &amp; Ss, mixed forest of Pm &amp; Ss, and the mixed forest of Lf &amp; Pm) were chosen in Taihe County, southern China. The results found that the mixed vegetation restoration of Lf &amp; Pm significantly improved the soil fauna abundance and biomass when compared with other reforestation models in the degraded red soil region. Acari and Collembola accounted for 65.8% and 23.3%, respectively, of the total soil fauna abundance in the region. The mixed forest of Lf &amp; Pm had a positive effect on the abundance of secondary decomposers and micro predators in Acari. Moreover, a significant increase in the abundance of Collembola was found in the Lf &amp; Pm stand type. The stand type with the highest soil faunal population also had a higher soil fauna biomass. Therefore, reforestation in a degraded red soil area had positive effects on the soil fauna community.

Microplastics in soil ecosystems: soil fauna responses to field applications of conventional and biodegradable microplastics

Although biodegradable plastics are considered an environmentally-friendly alternative to conventional plastics, the effects of biodegradable microplastics (BMPs) on soil faunal communities are poorly understood, especially under field conditions. Here, we investigated the loading impacts of two conventional low-density polyethylene (LDPE) and polypropylene (PP) MPs as well as two biodegradable polylactic acid (PLA) and polybutylene succinate (PBS) MPs at concentrations of 0, 5, 10, and 15 g/m2 on soil fauna communities. After 40 d, all MP types did not affect the soil fauna communities. After 130 d, conventional MPs (LDPE-15 and PP-5) significantly increased the abundance of overall soil fauna—attributed mainly to changes in the abundance of Collembola; however, BMPs did not affect the soil fauna communities. Interestingly, MP-induced changes in the abundance and diversity of soil fauna showed a strong tendency to increase over time. Overall, these results indicate that the short-term effects of all MP types on soil faunal communities are inapparent, while soil fauna responses to conventional MPs and BMPs showed slight differences over time. Given these time-dependent soil fauna responses to MPs, we recommend an evaluation of the long-term effects of MPs on soil organisms to gain a comprehensive understanding of their effects on soil ecosystems.

Implication of microplastics on soil faunal communities - identifying gaps of knowledge.

There is mounting evidence that plastic and microplastic contamination of soils can affect physico-chemical processes and soil fauna, as has been excellently summarised in many recently published meta-analyses and systematic reviews elsewhere. It has become clear that impacts are highly context dependent on, e.g. polymer type, shape, dose and the soil itself. Most published studies are based on experimental approaches using (semi-)controlled laboratory conditions. They typically focus on one or several representative animal species and their behaviour and/or physiological response - for example, earthworms, but rarely on whole communities of animals. Nevertheless, soil animals are rarely found in isolation and form part of intricate foodwebs. Soil faunal biodiversity is complex, and species diversity and interactions within the soil are very challenging to unravel, which may explain why there is still a dearth of information on this. Research needs to focus on soil animals from a holistic viewpoint, moving away from studies on animals in isolation and consider different trophic levels including their interactions. Furthermore, as evidence obtained from laboratory studies is complemented by relatively few studies done in field conditions, more research is needed to fully understand the mechanisms by which plastic pollution affects soil animals under realistic field conditions. However, field-based studies are typically more challenging logistically, requiring relatively large research teams, ideally of an interdisciplinary nature to maintain long-term field experiments. Lastly, with more alternative, (bio)degradable and/or compostable plastics being developed and used, their effects on soil animals will need to be further researched.

Illuminating biodiversity changes in the ‘Black Box’

Soil is often described as a ‘black box’, as surprisingly little is known about the high levels of biodiversity that reside there. For aboveground organisms, we have good knowledge of the distribution of the species and how they might change under future human impacts. Yet despite the fact that soil organisms provide a wide variety of ecosystem functions, we have very limited knowledge of their distribution and how their diversity might change in the future. In order to create accurate and generalisable models of biodiversity, the underlying data need to be representative of the entire globe. Yet even with our recently compiled global earthworm dataset of over 11000 sites, there are gaps across large regions. These gaps are consistent across many other datasets of both above- and belowground diversity. In order to fill the gaps we propose a sampling network (SoilFaUNa), to create a comprehensive database of soil macrofauna diversity and soil functions (e.g. decomposition rates). Building on the existing dataset of earthworm diversity and early data from the SoilFaUNa project, we will investigate changes in earthworm diversity. From our current work, we know that both climate and land use are main drivers in predicting earthworm diversity, but both will change under future scenarios and may alter ecosystem functions. We will, using space-for-time substitution models, estimate how earthworm diversity and their functions might change in the future, modelling earthworm diversity as a function of climate, land use and soil properties and predicting based on future scenarios. Previous studies of aboveground diversity changes over time using time-series analysis have found no-net-loss in richness, but analyses have criticisms. We aim to use time-series data on earthworms to move this debate forward, by using data and statistical methods that would address the criticisms, whilst increasing our knowledge on this understudied soil group. Field experiments and micro-/mesocosm experiments have been used to investigate the link between a number of soil organisms and ecosystem functions under few environmental conditions. Meta-analyses, which can produce generalisable results can only answer questions for which there are data. Thus, we have been lacking on information on the link between the entire community of soil fauna and ecosystem functions and impact of changes to the soil fauna community across environmental contexts. Using data collected from the SoilFaUNa project, we will, for the first time, synthesise globally distributed specifically-sampled data to model how changes in the community composition of soil macrofauna (due to changes in land use, climate or soil properties) impact the ecosystem functions in the soil.

Preface: Functional biogeography in Japanese cedar

Preface: Functional biogeography in Japanese cedar

Response of Soil Fauna Diversity to Agricultural Landscape Het-Erogeneity in the Middle and Lower Reaches of the Yellow River—A Case Study in Gongyi City, China

Soil fauna contribute to important ecological functions such as improving soil structure and promoting nutrient circulation. They are the common environmental indicators in agricultural landscape. Therefore, this study took Gongyi City, Henan Province, China, located in the middle and lower reaches of the Yellow River, as the study area, to explore the impact of multi-scale landscape heterogeneity on soil fauna diversity and the response of soil fauna to it. Our results showed that patch types and degree of fragmentation in the study area increased significantly with the increase of spatial scale. The diversity indices of soil fauna in different habitats showed that the Shannon-Wiener diversity index, Simpson’s diversity index, Pielou’s evenness index, and Margalef richness index were the lowest in farmland habitat. Diversity indices of artificial forests were higher than those of natural forests. Diversity indices of soil fauna under different geomorphic conditions showed that Pielou’s evenness index and Margalef richness index had significant differences under different geomorphic conditions (p &lt; 0.05). The effects of multi-scale landscape heterogeneity on soil fauna diversity were different. In the 150 m buffer zone, soil fauna community composition and diversity indices were strongly correlated with patch richness index, patch richness density, and other landscape indices (p &lt; 0.05). Meanwhile, the contribution rate of landscape index to soil fauna community composition were 45.05%, 32.5%, and 42% in farmland, plantation, and natural forest, respectively. Therefore, the 150 m buffer zone could be used as the characteristic response scale of soil fauna diversity. The multi-scale interaction of landform, habitat, and landscape also had a significant impact on soil fauna diversity.

Changes in the abundance and species diversity of Collembola community along with dwarf bamboo density gradient in a mountainous temperate forest of Japan

Understory vegetation plays an important role in forest ecosystems by providing protection from soil physicochemical stresses or disturbance. Consequently, this type of vegetation may help maintain soil biodiversity and functions. However, the effects of understory degradation on soil faunal communities is not well understood. This study investigated the effects of the declining understory dwarf bamboo density in cool-temperate Japanese deciduous forests on the community composition of soil Collembola; by comparing partitioned community dissimilarity indices and trait components to detect the processes shaping community under understory degradation. For the species richness and diversity of Collembola community, unimodal quadratic model to dwarf bamboo density was selected as best model among all measured environmental properties, whereas, for Collembola abundance, linear negative relationship to dwarf bamboo density was selected as best model. For Collembola trait compositions, dwarf bamboo density model was not selected, although those of soil C and hardness were selected. The nestedness component in community dissimilarity increased with greater dwarf bamboo density differences between plots, whereas the replacement component was not significant. This suggests that the decreasing dwarf bamboo density might induce reduced niche space of whole Collembola community. In the range of mid to high density of dwarf bamboo, the higher density of dwarf bamboo declined the species diversity of the Collembola community, whereas the abundance still increased, probably because of the competitive exclusion by the dominant Folsomia octoculata under less disturbed habitat condition in high understory and litter coverage. Our results implied that the changes in the abundance and species diversity of Collembola community to understory density gradient were controlled both by abiotic niche reduction and biotic competitive exclusion without life-form trait selection.

Faunal communities mediate the effects of plant richness, drought, and invasion on ecosystem multifunctional stability

Understanding the stability of ecosystem multifunctionality is imperative for maintaining ecosystem health and sustainability under augmented global change. However it remains unknown whether and how biological communities mediate multifunctional stability in response to biodiversity loss and disturbances. Here, we conducted a 3-year experiment by exposing 270 plant communities of four plant richness levels, i.e., 1, 2, 4, or 8 species, to drought and exotic plant invasion disturbances. Then, the direct effects of plant richness, drought and invasion, and their indirect effects mediated by the stability of plant, litter-faunal, and soil-faunal communities on multifunctional stability were disentangled. We found that plant richness increased, while drought and invasion decreased ecosystem multifunctional stability, which were mediated by plant or faunal community stability. By incorporating the stability of communities into the complex ecological mechanisms, the completeness and goodness of ecological models for explaining and maintaining the stability of ecosystem multifunctionality will be improved.

Soil Arthropod Community in Spruce Forests (Picea abies) Affected by a Catastrophic Storm Event

At the end of October 2018, the “Vaia” storm hit the eastern sector of the Italian Alps, causing major damage to forests. The resulting changes in habitat and resource availability are expected to shape the structure and abundance of soil communities. In this research, a soil arthropod community is studied one year after the catastrophic Vaia event in forests affected by the storm (W: Windthrow) to highlight the shift in the soil faunal community in a Mediterranean area increasingly impacted by climate change. Intact forests (IF) close to W were studied as a control condition and meadows (M) were considered to understand if W is moving toward a conversion to M or if the wooded character still prevails. Soil organic matter content was higher in IF than in W and M. The arthropod community was different between M and forests, both W and IF, while no differences were detected between W and IF considering the whole soil arthropod community. The Vaia catastrophic event does not appear to have radically changed the soil arthropod community and biodiversity after one year, despite upheaval to the vegetation cover, but the response is partially OTU (operative taxonomic unit)-specific. Hymenoptera adults and Coleoptera and Diptera larvae appear to be the most affected OTUs, showing lower abundance in W than IF. Conversely, Chilopoda seemed to benefit from the habitat changes, the result strongly related with the W condition. The two most present OTUs, Collembola and Acarina, were not affected by the Vaia storm. We may conclude that the soil system needs longer time to show a clear shift in the soil arthropod community.

Technosol rehabilitation strategies drive soil physico-chemical properties and fauna diversity on a former coking plant area

Anthropic activities such as mining, resource extraction or transformation profoundly modify ecosystems and may lead to Technosol formation. Post-industrial areas are examples of potentially degraded lands, due to soil contamination with metals or organic pollutants, as well as soil structure damage. Soil biodiversity being closely involved in many soil functions such as organic matter decomposition, formation and stabilization of soil structure, the recovery of degraded soil functions partly depends on soil fauna colonization. However, the relationship between Technosol abiotic parameters and soil fauna colonization is still to be disentangled. In an attempt to fill this gap, we studied a former coking plant area in north-eastern France, composed of Technosols resulting from coking plant embankments or thermally-treated industrial soils and compared them with two local soils considered as references. We hypothesized that the taxonomic and trophic diversity of Technosol-dwelling invertebrates would be more diverse and abundant in the soils with the higher soil physico-chemical quality (i.e higher fertility and lower pollutions levels). To test this hypothesis, we studied four Technosols that were settled following two different rehabilitation strategies within the same post-industrial area and we compared them with two local soils of reference using nested ANOVAs as well as multivariate analyses of soil abiotic parameters and soil fauna community indices, both within the soil and on its surface.The results on physico-chemical analyses showed that the substrates used for Technosol rehabilitation were impoverished in clay content when compared with local soils of reference (4.1 to 7.8-fold) and enriched in sandy materials. The use of coking plant by-products for Technosol implementation have led to poor chemical quality, with low nutrient content but high organic carbon content (41 to 51%) resulting from the use of coal and correlated with the higher lead concentration in the area. The use of thermally-treated industrial soil has led to more fertile Technosols with significantly lower lead content. Meso and macrofauna densities did not vary significantly between the Technosols and the local reference soils. Both Technosol-dwelling fauna trophic and taxonomic community compositions were impacted by the rehabilitation strategy. Few to no earthworms were found in Technosols (mean up to 16 ind.m−2) compared to the local soils of reference (mean of 118.4 and 201.6 ind.m−2). Conversely, Technosols resulting from coking plant embankments and thermally-treated industrial soils were dominated by epigeic soil fauna with an intense activity of soil surface macro-saprophages and micro-arthropods, as well as Formicidae. Our results suggest that the use of technogenic elements in the rehabilitation of post-industrial area led to the development of specific soil invertebrate communities, different from the reference. The gap between the high level of activity of epigeic organisms that we found on Technosols and the low trophic diversity of the litter and soil-dwelling communities suggest that the soil fauna community on a former coking plant is driven rather by soil physico-chemical properties than by colonization constraints.

Fertilization Rapidly Alters the Feeding Activity of Grassland Soil Mesofauna Independent of Management History

Nitrogen fertilization of permanent grasslands affects soil fauna communities by modifying their taxonomic composition, population dynamics and feeding activity. However, it is not well understood if the edaphic fauna adapts to these external inputs so that the immediate response to fertilizer application depends on the long-term nutrient management strategy. We performed a field experiment in permanent grasslands under agricultural management in three regions across Germany. We used experimental fertilization with an organic plant-sourced fertilizer along a long-term nutrient management gradient to study the immediate and long-term effects of fertilization and their interdependence on the taxonomic composition and feeding activity of the soil mesofauna (Nematoda, Oribatida, and Collembola). Sampling season, soil properties, vegetation structure, and geographic location were considered as additional predictor variables to reflect heterogeneity in environmental conditions. The taxonomic composition, richness and total abundance of soil mesofauna communities were significantly affected by long-term nutrient management, but not by experimental fertilization. However, N pulses rapidly (within days) reduced the feeding activity estimated with bait-lamina strips independent of long-term nutrient management strategies. Experimental addition of organic plant-sourced fertilizer may have led to a rapid build-up of microbial biomass, providing alternative food sources for the soil mesofauna and causing a shift away from the bait-lamina substrate. Our study indicates that community changes associated with the long-term nutrient management regime in permanent grasslands do not alter the strong functional response of the soil mesofauna to N pulses. There is an urgent need to develop nutrient management strategies for permanent grasslands that take into account both the conservation of the edaphic faunal community and changes of ecosystem functions caused by rapid responses of the soil mesofauna to fertilizer inputs.

Effects of long-term nitrogen addition and seasonal variation on soil faunal community structure in a temperate natural secondary forest

Effects of long-term nitrogen addition and seasonal variation on soil faunal community structure in a temperate natural secondary forest

Distribution Patterns of Soil Fauna in Different Forest Habitat Types of North Hebei Mountains, China

The relationship between soil fauna distribution and forest habitat types is an ongoing concern. In this study, the distributions of soil fauna communities were investigated and compared in three forests of Betula platyphylla, Picea asperata, and Pinus sylvestris. A total of 39 groups of soil fauna belonging to four functional groups were found, with Acarina and Collembola being the dominant groups, and omnivorous and saprophagous being the dominant functional groups. An investigation on the temporal and spatial distribution of the soil fauna found similar changes in the three forests: the abundance of soil fauna was higher in August and September and lowest in May; explicit surface aggregation of the soil fauna emerged; and the density and group number decreased with the increase in soil depth. Via comparison, the total abundance of soil fauna in the B. platyphylla forest (16,772 ind m−2) was found to be higher than that in the P. asperata (12,972 ind m−2) and P. sylvestris (14,250 ind m−2) forests, and the indexes of diversity, richness and evenness of the soil fauna community in the B. platyphylla forest were the highest. Redundancy analysis showed that soil organic matter (SOC), total nitrogen (TN), and total phosphorus (TP) were positively correlated with soil fauna density, whereas pH and bulk density (BD) were negatively correlated. Compared with the two coniferous forests, the physicochemical factors positively (negatively) correlated with soil fauna density were the highest (lowest) in the B. platyphylla forest. The combined effect of these multiple factors suggests that the B. platyphylla forest recovered the most favorable conditions for the living and development of the soil fauna. The findings in this research may help us to understand the restoration effect of soil fauna in different forest habitat types, providing support for forest sustainable management in northern Hebei Mountain ecosystems.

Role of earthworms in soil fertility and its impact on agriculture: A review

Soil fertility is defined as the capacity of a specific kind of soil to function, within natural or managed ecosystem boundaries to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation. Perhaps no other living organism in the soil is as important as an earthworm in helping to increase soil health. Earthworms are the most commonly occur in the soil. The activities of burrowing and feeding by earthworms have many valuable effects generally on soil quality for crop production. Earthworms increase soil aeration, infiltration, structure, nutrient cycling, water movement, and plant growth. Earthworms are one of the major decomposers of organic matter. They get their nutrition from microorganisms that live on organic matter and in soil material. When they move through the soil eating, earthworms form tubular channels or burrows. These burrows can persist for a long time in the soil. Earthworm burrows increase soil porosity which increases the amount of air and water that get into the soil. Increased porosity also lowers bulk density and increases root development. Earthworm excrement or casts increase soil fertility because it contains nitrogen, phosphorus, potassium, and magnesium. Earthworm casts also contain microorganisms which increase in abundance as organic matter is digested in their intestines. The cycling of nutrients from organic matter and the increase in microorganisms facilitates plant growth. They cast along with binding agents released by earthworms also improve soil structure and increase aggregate stability. The soil biota benefits soil productivity and contributes to the sustainable function of all ecosystems. The cycling of nutrients is a critical function that is essential to life on earth. Earthworms (EWs) are a major component of soil fauna communities in most ecosystems and comprise a large proportion of macrofauna biomass. Their activity is beneficial because it can enhance soil nutrient cycling through the rapid incorporation of detritus into mineral soils. In addition to this mixing effect, mucus production associated with water excretion in earthworm guts also enhances the activity of other beneficial soil microorganisms. This is followed by the production of organic matter. So, in the short term, a more significant effect is the concentration of large quantities of nutrients (N, P, K, and Ca) that are easily assimilable by plants in fresh cast depositions. In addition, earthworms seem to accelerate the mineralization as well as the turnover of soil organic matter. Earthworms are known also to increase nitrogen mineralization, through direct and indirect effects on the microbial community. The increased transfer of organic C and N into soil aggregates indicates the potential for earthworms to facilitate soil organic matter stabilization and accumulation in agricultural systems, and that their influence depends greatly on differences in land management practices.