Quantification of the inevitable: the influence of soil macrofauna on soil water movement in rehabilitated open-cut mined lands

Recolonisation of soil by macrofauna (especially ants, termites and earthworms) in rehabilitated open-cut mine sites is inevitable and, in terms of habitat restoration and function, typically of great value. In these highly disturbed landscapes, soil invertebrates play a major role in soil development (macropore configuration, nutrient cycling, bioturbation, etc.) and can influence hydrological processes such as infiltration, seepage, runoff generation and soil erosion. Understanding and quantifying these ecosystem processes is important in rehabilitation design, establishment and subsequent management to ensure progress to the desired end goal, especially in waste cover systems designed to prevent water reaching and transporting underlying hazardous waste materials. However, the soil macrofauna is typically overlooked during hydrological modelling, possibly due to uncertainties on the extent of their influence, which can lead to failure of waste cover systems or rehabilitation activities. We propose that scientific experiments under controlled conditions and field trials on post-mining lands are required to quantify (i) macrofauna–soil structure interactions, (ii) functional dynamics of macrofauna taxa,and (iii) their effects on macrofauna and soil development over time. Such knowledge would provide crucial information for soil water models, which would increase confidence in mine waste cover design recommendations and eventually lead to higher likelihood of rehabilitation success of open-cut mining land.

Why is the influence of soil macrofauna on soil structure only considered by soil ecologists?

These last twenty years have seen the development of an abundant literature on the influence of soil macrofauna on soil structure. Amongst these organisms, earthworms, termites and ants are considered to play a key role in regulating the physical, chemical and microbiological properties of soils. Due to these influential impacts, soil ecologists consider these soil macro-invertebrates as `soil engineers' and their diversity and abundance are nowadays considered as relevant bioindicators of soil quality by many scientists and policy makers. Despite this abundant literature, the soil engineering concept remains a `preach to the choir' and bioturbation only perceived as important for soil ecologists. We discussed in this article the main mechanisms by which soil engineers impact soil structure and proposed to classify soil engineers with respect to their capacity to produce biostructures and modify them. We underlined the lack of studies considering biostructure dynamics and presented recent techniques in this purpose. We discussed why soil engineering concept is mainly considered by soil ecologists and call for a better collaboration between soil ecologists and soil physicists. Finally, we summarized main challenges and questions that need to be answered to integrate soil engineers activities in soil structure studies. (C) 2014 Elsevier B.V. All rights reserved.

Evaluating the efficiency of sampling methods in assessing soil macrofauna communities in arable systems

The soil fauna is often a neglected group in many large-scale studies of farmland biodiversity due to difficulties in extracting organisms efficiently from the soil. This study assesses the relative efficiency of the simple and cheap sampling method of handsorting against Berlese-Tullgren funnel and Winkler apparatus extraction. Soil cores were taken from grassy arable field margins and wheat fields in Cambridgeshire, UK, and the efficiencies of the three methods in assessing the abundances and species densities of soil macroinver-tebrates were compared. Handsorting in most cases was as efficient at extracting the majority of the soil macrofauna as the Berlese-Tullgren funnel and Winkler bag methods, although it underestimated the species densities of the woodlice and adult beetles. There were no obvious biases among the three methods for the particular vegetation types sampled and no significant differences in the size distributions of the earthworms and beetles. Proportionally fewer damaged earthworms were recorded in larger (25 x 25 cm) soil cores when compared with smaller ones (15 x 15 cm). Handsorting has many benefits, including targeted extraction, minimum disturbance to the habitat and shorter sampling periods and may be the most appropriate method for studies of farmland biodiversity when a high number of soil cores need to be sampled. (C) 2008 Elsevier Masson SAS. All rights reserved.

Can arable field margins be managed to enhance their biodiversity, conservation and functional value for soil macrofauna?

1. The establishment of grassy strips at the margins of arable fields is an agri-environment scheme that aims to provide resources for native flora and fauna and thus increase farmland biodiversity. These margins can be managed to target certain groups, such as farmland birds and pollinators, but the impact of such management on the soil fauna has been poorly studied. This study assessed the effect of seed mix and management on the biodiversity, conservation and functional value of field margins for soil macrofauna. 2. Experimental margin plots were established in 2001 in a winter wheat field in Cambridgeshire, UK, using a factorial design of three seed mixes and three management practices [spring cut, herbicide application and soil disturbance (scarification)]. In spring and autumn 2005, soil cores taken from the margin plots and the crop were hand-sorted for soil macrofauna. The Lumbricidae, Isopoda, Chilopoda, Diplopoda, Carabidae and Staphylinidae were identified to species and classified according to feeding type. 3. Diversity in the field margins was generally higher than in the crop, with the Lumbricidae, Isopoda and Coleoptera having significantly more species and/or higher abundances in the margins. Within the margins, management had a significant effect on the soil macrofauna, with scarified plots containing lower abundances and fewer species of Isopods. The species composition of the scarified plots was similar to that of the crop. 4. Scarification also reduced soil- and litter-feeder abundances and predator species densities, although populations appeared to recover by the autumn, probably as a result of dispersal from neighbouring plots and boundary features. The implications of the responses of these feeding groups for ecosystem services are discussed. 5. Synthesis and applications. This study shows that the management of agri-environment schemes can significantly influence their value for soil macrofauna. In order to encourage the litter-dwelling invertebrates that tend to be missing from arable systems, agri-environment schemes should aim to minimize soil cultivation and develop a substantial surface litter layer. However, this may conflict with other aims of these schemes, such as enhancing floristic and pollinator diversity.

Effects of metal pollution on soil macroinvertebrate burrow systems

A reduction in the numbers of macroinvertebrates present in soil may have a negative effect on soil structure, infiltration rates, and gas exchanges. Soil pollution by metal is known to have a detrimental effect on soil macrofauna. The aim of the present study was to evaluate (1) direct and indirect effects of soil pollution on soil macroinvertebrate bioturbation and (2) effects of the two macroinvertebrate communities found in a polluted and a nonpolluted area (one supposed sensitive, the other tolerant to metals) on burrow systems parameters. Macroinvertebrate porosity was studied using X-ray tomography. Three-dimensional reconstructions and characterisation of the burrow system were obtained using image analysis. Results showed that metal pollution principally affected the spatial distribution of macropores (more macropores were found near the soil surface) and the shape of the burrow system (branching rate was higher in the polluted soil), whereas soil macroinvertebrate composition principally affects burrow density parameters (the number of burrows was higher for the sensitive macroinvertebrate community).

Does changing the taxonomical resolution alter the value of soil macroinvertebrates as bioindicators of metal pollution?

Ecological indicators are taxa that are affected by, and indicate effects of, anthropogenic environmental stress or disturbance on ecosystems. There is evidence that some species of soil macrofauna (i.e. diameter > 2 min) constitute valuable biological indicators of certain types of soil perturbations. This study aims to determine which level of taxonomic resolution, (species, family or ecological group) is the best to identify indicator of soil disturbance. Macrofauna were sampled in a set of sites encompassing different land-use systems (e.g. forests, pastures, crops) and different levels of pollution. Indicator taxa were sought using the IndVal index proposed by Dufrene and Legendre [Dufrene, M., Legendre, P., 1997. Species assemblages and indicator species: the need for a flexible asymetrical approach. Ecological Monographs 67, 345-3661. This approach is based on a hierarchical typology of sites. The index value changes along the typology and decreases (increases) for generalist (specialist) faunal units (species, families or ecological groups). Of the 327 morphospecies recorded, 19 were significantly associated with a site type or a group of sites (5.8%). Similarly, species were aggregated to form 59 families among which 17 (28.8%) displayed a significant indicator value. Gathering species into 28 broad ecological assemblages led to 14 indicator groups (50%). Beyond the simple proportion of units having significant association with a given level of the site typology, the proportion of specialist and generalist groups changed dramatically when the level of taxonomic resolution was altered. At the species level 84% of the indicator units were specialist, whereas this proportion decreased to 70 and 43% when families and ecological groups were considered. Because specialist groups are the most interesting type of indicators either in terms of conservation or for management purposes we come to the conclusion that the species level is the most accurate taxonomic level in bioindication studies although it requires a high amount of labour and operator knowledge and is time-consuming. (c) 2005 Published by Elsevier Ltd.

The value of sown grass margins for enhancing soil macrofaunal biodiversity in arable systems

The presence of a grass strip was found to be beneficial to soil macrofauna, increasing the species densities and abundances of earthworms, woodlice and staphylinid beetles. The biodiversity of the three main feeding groups - predators, soil ingesters and litter consumers - was also significantly higher in the grass strips than in the field edges without strips, indicating that establishment of grassy margins in arable fields may enhance ecosystem services such as soil fertility and pest control. The grass strip habitat contained a large number of species of soil macrofauna, being second only to hedgerow habitat, with 10% of the total species list for the farm found only within the margins. Of the rare species recorded on the farm, five of the nine were from the grass strips, four of which were found only there. This study shows that establishing grassy strips in the margins of arable fields increases the biodiversity of the soil macrofauna, both within fields (alpha diversity) and across the farm (beta diversity). (C) 2008 Elsevier B.V. All rights reserved.

The value of arable field margins for enhancing soil macrofaunal biodiversity in agroecosystems

The presence of a grass strip was found to be beneficial to soil macrofauna, increasing the species densities and abundances of earthworms, woodlice and staphylinid beetles. The biodiversity of the three main feeding groups – predators, soil ingesters and litter consumers – was also significantly higher in the grass strips than in the field edges without strips, indicating that establishment of grassy margins in arable fields may enhance ecosystem services such as soil fertility and pest control. The grass strip habitat contained a large number of species of soil macrofauna, being second only to hedgerow habitat, with 10% of the total species list for the farm found only within the margins. Of the rare species recorded on the farm, five of the nine were from the grass strips, four of which were found only there. This study shows that establishing grassy strips in the margins of arable fields increases the biodiversity of the soil macrofauna, both within fields (alpha diversity) and across the farm (beta diversity).

GISQ, a multifunctional indicator of soil quality

We present here an indicator of soil quality that evaluates soil ecosystem services through a set of 5 subindicators, and further combines them into a single general Indicator of Soil Quality (GISQ). We used information derived from 54 properties commonly used to describe the multifaceted aspects of soil quality. The design and calculation of the indicators were based on sequences of multivariate analyses. Subindicators evaluated the physical quality, chemical fertility, organic matter stocks, aggregation and morphology of the upper 5 cm of soil and the biodiversity of soil macrofauna. A GISQ combined the different subindicators providing a global assessment of soil quality. Research was conducted in two hillside regions of Colombia and Nicaragua, with similar types of land use and socio-economic context. However, soil and climatic conditions differed significantly. In Nicaragua, soil quality was assessed at 61 points regularly distributed 200 m apart on a regular grid across the landscape. In Colombia, 8 plots representing different types of land use were arbitrarily chosen in the landscape and intensively sampled. Indicators that were designed in the Nicaragua site were further applied to the Colombian site to test for their applicability. In Nicaragua, coffee plantations, fallows, pastures and forest had the highest values of GISQ (1.00; 0.80; 0.78 and 0.77, respectively) while maize crops and eroded soils (0.19 and 0.10) had the lowest values. Examination of subindicator values allowed the separate evaluation of different aspects of soil quality: subindicators of organic matter, aggregation and morphology and biodiversity of macrofauna had the maximum values in coffee plantations (0.89; 0.72 and 0.56, respectively on average) while eroded soils had the lowest values for these indicators (0.10; 0.31 and 0.33, respectively). Indicator formulae derived from information gained at the Nicaraguan sites were not applicable to the Colombian situation and site-specific constants were calculated. This indicator allows the evaluation of soil quality and facilitates the identification of problem areas through the individual values of each subindicator. It allows monitoring of change through time and can guide the implementation of soil restoration technologies. Although GISQ formulae computed on a set of data were only valid at a regional scale, the methodology used to create these indices can be applied everywhere.

Efeitos das variáveis ambientais locais sobre a abundância, a riqueza e a biomassa da macrofauna de solo em um ecossistema semiárido no estado do rio grande do norte, nordeste do brasil

The soil macrofauna is influenced to several biotic and abiotic environmental factors, from changes in the physical environment to a variety of interactions among the species involved, affecting the patterns of biodiversity of soil fauna. The power and specificity of the mechanisms that act on soil organisms vary greatly depending on environmental conditions at different scales of space and time. The Caatinga has great spatial heterogeneity of vegetation, climate and soil, so the soil macrofauna would follow this local spatial variation in the environment? This study aimed to investigate the effects of local environmental variables on biological parameters (taxa richness, total abundance and biomass) of soil macrofauna in a fragment of caatinga in João Câmara, Rio Grande Norte, Northeast Brazil. The study was conducted in the Cauaçu farm, where a grid of 2000m x 500m was drawn, and later, 30 sampling points were randomly selected. The methodology used to collect the macrofauna was the TSBF method. We tested the effects of 10 environmental variables on macrofauna across the plots and across the layers of soil. The hypothesis that macrofauna soil responds to changes in the environment was not supported throughout the plots, but was confirmed to soil layers. The soil macrofauna shows a pattern of concentration in the surface layer and decreases considerably in the deeper layers. This pattern had significant and positive relationship with the aerial plant biomass and fine root stock. The aerial plant biomass releases plant necromass that accumulates in the surface layer, providing an important source of resource and shelter for soil macrofauna, explaining their greater abundance in this layer. The roots are used as a means for the arrival of nutrients to the soil from the primary production, thus a greater amount of root conditions higher food intake for macrofauna, especially the herbivores

Frações oxidáveis do carbono orgânico total e macrofauna edáfica em sistema de integração lavoura-pecuária

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relação entre macrofauna, agregação e atributos edáficos em sequência de culturas sob plantio direto

Pós-graduação em Agronomia (Agricultura) - FCA

Macrofauna epígea de besouros coprófilos em sistema de integração lavoura-pecuária

The soil macrofauna (organisms ≥ 2.0 mm) main function is to act indirectly on the decomposition of organic matter and control the population of microorganisms. This study aims to evaluate the density and richness of coprphilic dung beetles at different levels of nitrogen fertilization and grazing pressure on Crop-Livestock Integration System (ILP) and his opposition to morphotypes present in the native forests of the region. Was used a rural area in Abelardo Luz city, western state of Santa Catarina, on the border of southwest of Paraná, 26° 31' 18.8832" south latitude and 52° 15' 3.4986' west longitude and elevation 862 m for the installation of the experiment, which is already carried out the activity of agriculture and livestock. The study is part of the Integrated Project of Long Duration GISPA UTFPR Group, which evaluates the grazing pressure and time of fertilization deployed in April 2013. The experimental design was a randomized complete block design in a 2x2 factorial arrangement with three replications. The factors were "Nitrogen Application" (NP = N in the pasture and NG = N applied in corn) and "Height Grazing" (high and low). The native forest, which provided the parameters for assessing the degree of conservation, lies 700 meters northeast of the experimental area. Modified pitfall traps were used at ground level, on the bait trap and covered together to prevent dehydration. They were carried out 36 collections in bushland, within one year from 26 April 2013, in which we obtained a total of 16,301 individuals and 28 morphotypes. In ILP area specimens were collected from June to September 2014, totaling 23 collections, 74,586 individuals and 30 morphotypes. To carry out the statistics and faunal analysis, GENES programs were used, ANAFAU, NTIA/EMBRAPA and SigmaPlot version 12.5. Most of the correlations observed (90%) between the variables of insects and environmental conditions was significant. The largest number of insects was directly related to the temperature rise. There was a positive correlation between the application of nitrogen and the occurrence of coprophilous. There was a positive correlation between the number of insects and low grazing height. It was also found that some of the insects migrate from the culture to the area of native forest after reaching their peak population. The great similarity of results observed in the native forest and the ILP System indicates the ecological benefits of adopting this technology.

Program, abstracts and related documents.

The context: Soil biodiversity and sustainable agriculture; Abstracts - Theme 1: Monitoring and assessment: Bioindicators of soil health: assessment and monitoring for sustainable agriculture; Practical tools to measure soil health and their use by farmers; Biological soil quality from biomass to biodiversity - importance and resilience to management stress and disturbance; Integrated management of plant-parasitic nematodes in maize-bean cropping systems; Microbial quantitative and qualitative changes in soils under different crops and tillage management systems in Brazil; Diversity in the rhizobia associated with Phaseolus vulgaris L: in Ecuador and comparisons with Mexican bean rhizobia; Sistemas integrados ganadería-agricultura en Cuba; Soil macrofauna as bioindicator of soil quality; Biological functioning of cerrado soils; Hydrolysis of fluorescein diacetate as a soil quality indicator in different pasture systems; Soil management and soil macrofauna communities at Embrapa Soybean, Londrina, Brazil; Soil macrofauna in a 24 - year old no-tillage system in Paraná, Brazil; Invertebrate macrofauna of soils inpastures under different forms of management in the cerrado (Brazil); Soil tillage modifies the invertebrate soil macrofauna community; Soil macrofauna in various tillage and land use systems on an oxisols near Londrina, Paraná, Brazil; Interference of agricultural systems on soil macrofauna; Scarab beetle-grub holes in various tillage and crop management systems at Embrapa Soybean, Londrina, Brazil; Biological management of agroecosystems; Soil biota and nutrient dynamics through litterfall in agroforestry system in Rondônia, Amazônia, Brazil; Soil-C stocks and earthworm diversity of native and introduced pastures in Veracruz, Mexico; Theme 2 : Adaptive management: Some thoughts on the effects and implications of the transition from weedy multi-crop to wead-free mono-crop systems in Africa; Towards sustainable agriculture with no-tillage and crop rotation systems in South Brazil; Effect of termites on crusted soil rehabilitation in the Sahel; Management of macrofauna in traditional and conventional agroforestry systems from India with special reference to termites and earthworms; Adaptive management for redeveloping traditional agroecosystems; Conservation and sustainable use of soil biodiversity: learning with master nature!; Convergence of sciences: inclusive technology innovation processes for better integrated crop/vegetation, soil and biodiversity management; Potential for increasing soil biodiversity in agroecosystems; Biological nitrogen fixation and sustainability in the tropics; Theme 3: Research and innovation: Plant flavonoids and cluster roots as modifiers of soil biodiversity; The significance of biological diversity in agricultural soil for disease suppressiveness and nutrient retention; Linking above - and belowground biodiversity: a comparison of agricultural systems; Insect-pests in biologically managed oil and crops: the experience at ICRISAT; Sistemas agricolas micorrizados en Cuba; The effect of velvetbean (Mucuna pruriens) on the tropical earthworm Balanteodrilus pearsei: a management option for maize crops in the Mexican humid tropics; The potential of earthworms and organic matter quality in the rehabilitation of tropical soils; Research and innovation in biological management of soil ecosystems; Application of biodynamic methods in the Egyptian cotton sector; Theme 4: Capacity building and mainstreaming: Soil ecology and biodiversity: a quick scan of its importance for government policy in The Netherlands; Agrotechnological transfer of legume inoculants in Eastern and Southern Africa; Agricultura urbana en Cuba; Soil carbon sequestration for sustaining agricultural production and improving the environment; Conservation and sustainable management of below-ground biodiversity: the TSBF-BGBD network project; The tropical soil biology and fertility institute of CIAT (TSBF); South-South initiative for training and capacity building for the management of soil biology/biodiversity; Strategies to facilititate development and adoption of integrated resource management for sustainable production and productivity improvement; The challenge program on biological nitrogen fixation (CPBNF); Living soil training for farmers: improving knowledge and skills in soil nutrition management; Do we need an inter-governmental panel on land and soil (IPLS)? Protection and sustainable use of biodiversity of soils; Cases Studies -- Plant parasitic nematodes associated with common bean (Phaseolus vulgaris L.) and integrated management approaches; Agrotechnological transfer of legume inoculants in Eastern and Southern Africa; Restoring soil fertility and enhancing productivity in Indian tea plantations with earthworms and organic fertilizers; Managing termites and organic resources to improve soil productivity in the Sahel; Overview and case studies on biological nitrogen fixation: perspectives and limitations; Soil biodiversity and sustainable agriculture: an overview.