THE STATE OF GLOBAL ANIMAL GENETIC RESOURCES AND A NEW FAO PROGRAMME OF MANAGEMENT (2 nd part)

Background: Grazed grassland management regimes can have various effects on soil fauna. For example, effects on earthworms can be negative through compaction induced by grazing animals, or positive mediated by increases in sward productivity and cattle dung pats providing a food source. Knowledge gaps exist in relation to the behaviour of different earthworm species i.e. their movement towards and aggregation under dung pats, the legacy effects of pats and the spatial area of recruitment. The present study addressed these knowledge gaps in field experiments, over 2 years, using natural and simulated dung pats on two permanent, intensively grazed pastures in Ireland. Results: Dung pats strongly affected spatial earthworm distribution, with up to four times more earthworms aggregating beneath pats, than in the control locations away from pats. In these earthworm communities comprising 11 species, temporally different aggregation and dispersal patterns were observed, including absence of individual species from control locations, but no clear successional responses. Epigeic species in general, but also certain species of the anecic and endogeic groups were aggregating under dung. Sampling after complete dung pat disappearance (27 weeks after application) suggested an absence of a dung pat legacy effect on earthworm communities. Based on species distributions, the maximum size of the recruitment area from which earthworms moved to pats was estimated to be 3.8 m2 per dung pat. Since actual grazing over 6 weeks would result in the deposition of about 300 dung pats per ha, it is estimated that a surface area of 1140 m2 or about 11% of the total grazing area can be influenced by dung pats in a given grazing period. Conclusions: This study showed that the presence of dung pats in pastures creates temporary hot spots in spatial earthworm species distribution, which changes over time. The findings highlight the importance of considering dung pats, temporally and spatially, when sampling earthworms in grazed pastures. Published comparisons of grazed and cut grasslands probably reached incorrect conclusions by ignoring or deliberately avoiding dung pats. Furthermore, the observed intense aggregation of earthworms beneath dung pats suggests that earthworm functions need to be assessed separately at these hot spots.</p

Measuring respiration profiles of soil microbial communities across Europe using MicroResp™ method

A European "transect" was established to assess soil microbial activity, using the MicroResp™ method, as part of a larger project looking at soil biodiversity and function across Europe. 81 sites were sampled across five biogeographical zones described and mapped in the EEA report (. EEA, 2012) and included the following classes; Boreal, Atlantic, Continental, Mediterranean and Alpine, three land-use types (Arable, Grass and Forest) incorporating a wide range of soil pH, soil organic carbon (org C) and texture. Seven carbon substrates were used to determine multiple substrate induced respiration (MSIR), incorporating; acids, bases, sugars and amino acids. Substrates included: D-(+)-galactose, l-malic acid, gamma amino butyric acid, n-acetyl glucosamine, D-(+)-glucose, alpha ketogluterate, citric acid and water. MicroResp™ results showed discrimination of land-use type over a large spatial scale and response to soil pH and soil organic carbon. Substrates behaved differently depending upon combinations of land-use and soil properties specifically the greater utilisation of carboxylic acid based substrates in arable sites.</p

Soil protection for a sustainable future : options for a soil monitoring network for Ireland

The increased recognition of the importance of soil is reflected in the UN Post-2015 Development Agenda with sustainable development goals that directly and indirectly relate to soil quality and protection. Despite a lack of legally binding legislation for soil protection, the European Commission remains committed to the objective of soil protection. However, the achievement of a legally binding framework for soil protection relies on the implementation of a soil monitoring network (SMN) that can detect changes to soil quality over time. As beneficiaries do not pay for the provision of soil information, the options for soil monitoring are limited. The use of existing data sets should be considered first. Using Ireland as an example, this research explored the opportunities for a SMN for Ireland considering three existing national data sets. The options for a SMN are considered in terms of their spatial and stratified distribution, the parameters to be measured and an economic analysis of the options proposed. This research finds that for Ireland, either a 10 or a 16 km2 grid interval stratified by land use and drainage class offers the best potential in relation to the spatial distribution of existing data sets to reflect local data at a national level. With existing data, the stratified SIS data using the 16 km2 grid offers the best value for money, with baseline costs for analysis, excluding field costs, of between €706 481 and €2.8 million. Acknowledging the impossibility of measuring all parameters with ideal frequency, this study proposes a two-tier system for optimized monitoring frequency. Parameters must anticipate future policy requirements. Finally, the implementation of a SMN must be accompanied by standardized methods, defined thresholds and action mandates to maintain soil quality within allowable limits.</p

The life of soils: Integrating the who and how of multifunctionality

Capturing the complexity of soil life for soil quality assessments is one of the most challenging paradoxes of contemporary soil science. Soil biota perform a plethora of processes that are fundamental to soil quality. As the concept of soil quality developed, so have the attempts to integrate soil biological measurements into monitoring schemes from field to regional scale. To date, however, soil science has not yet succeeded to provide flexible yet objective biological indicator methods to assess soil multifunctionality, customised to the user's context.We present an integrative framework and elucidate the who and how of soil multifunctionality. The framework encompasses the current scientific understanding of the role of soil biota in supporting the many soil processes that underly soil quality. We specified these relationships for four soil functions (Carbon and Climate Regulation, Water Regulation and Purification, Nutrient Cycling, and Disease and Pest Regulation). We identify challenges often encountered in soil quality assessment and monitoring schemes and discuss how the framework can be applied to provide a flexible selection tool. Soil quality assessments are conducted in different contexts. As assessment objectives range from mechanistic understanding, to functional land management and large spatial scale monitoring so will the practical and logistical constraints for method selection vary.Biological assessments need to move beyond the quest for a one-size-fits-all minimum dataset, and adopt a more nuanced selection approach founded in soil biology. We stress that biological attributes should not be considered in isolation but alongside soil chemical and physical attributes, as well as management and environmental contextualisation. The presented framework offers a structure to further quantify, understand and communicate the who and how of soil biology in defining multifunctionality

Soil exo-enzyme activities across Europe-The influence of climate, land-use and soil properties

The assessment and monitoring requirements of soil quality have been debated for many years at European and Global scales. To monitor the activity and diversity of microbial communities a number of methods have been applied including the activity of extracellular soil enzymes. Here is the activity of eight hydrolytic extracellular enzymes on 79 sites across Europe measured, the sites are from five different climatic zones with three different land-uses, and they vary in physicochemical characteristics. The results show that the activity of the enzymes primarily depends on soil organic matter and to a lesser extent on pH, while the activities were not related to climate or land-use. Sites were selected to represent a broad spectrum of key soil properties across three different land-uses and five different climatic biogeographical zones across Europe, so the overall conclusion is based on the analysis of soils representing soil characteristics across Europe.</p

Validating digital soil maps using soil taxonomic distance : A case study of Ireland

Abstract Recently, there has been a marked increase across the world in the demand for digital soil information, in which digital soil mapping research plays a key role. Methods to validate these digital soil maps are needed. Soil maps, and in particular soil taxonomic maps contain embedded information that represents an understanding of the functioning of the soil within its landscape and the contributing soil forming factors. These cannot be easily validated by a straight point-to-polygon comparison. Furthermore, the uncertainty associated with a misclassification is not binary, but rather a more complex measure that accounts for the degree of divergence between the point observation and map unit that takes into account these underlying relationships between soils, landscape and function. Here we present a map validation approach based on the soil taxonomic divergence and compare this to the outcome from validation based on a straight binary presence/absence evaluation of the map units. We do so for the newly generated soils map of Ireland at a scale of 1:250,000. We find that the overall accuracy calculated through the presence absence method was 69% accurate, whereas the minimum taxonomic distance concept, has an overall accuracy of 90.1%. In particular, soil map units with large spatial coverage tended to be assessed as being very uncertain using the presence/absence method, the confidence around these map units was significantly improved using the minimum taxonomic distance approach. Where large differences were observed between field observations and mapped soil units, we found the taxonomic distance measure a more informative diagnostic as why these differences were observed.</p

The effects of earthworms, botanical diversity and fertiliser type on the vertical distribution of soil nutrients and plant nutrient acquisition : A mesocosm study

The application of phosphorus (P)-based fertiliser to agricultural soils can result in a skewed vertical distribution of P down the soil profile, since the element tends to accumulate at the soil surface. Such accumulation can have detrimental effects on the environment, as the erosion of surface soil can facilitate the transfer of large quantities of P out of the field into water bodies. Earthworm and plant communities are intricately linked to vertical nutrient distributions in soil, with both communities either facilitating or negating the incorporation of nutrients into the soil matrix. This study aimed to investigate the effect of earthworm presence, plant community structure and fertiliser type to affect the distribution of nutrients in experimental mesocosms; with particular emphasis on the vertical distribution of P. Mesocosms were designed to simulate a soil which has a high P concentration at the surface compared to further down the soil profile. It was hypothesised that the presence of earthworms would facilitate the incorporation of P into the soil matrix and the presence of a more botanically diversity community would assimilate a greater quantity of soil nutrients. After 1 year, mesocosms were deconstructed into five depth ranges, and the distribution of nutrients were modelled and analysed. Results indicated that the presence of earthworms did redistribute soil nutrients from the surface into the matrix beneath. This redistribution was apparent from a reduction in nutrient concentrations in the 0-1 cm depth range. The presence of a more botanically diverse community not only assimilated greater soil nutrient concentrations, but also promoted a less even vertical distribution of soil nutrients, demonstrating the importance of soil biota and plant diversity in the redistribution of soil nutrients.</p

The application of expert knowledge in Bayesian networks to predict soil bulk density at the landscape scale

This paper investigates the use of expert knowledge as a resource for digital soil mapping. To do this, three models of topsoil soil bulk density (Db) were produced: (i) a random forest model formulated and cross-validated with the limited data available (which served as the benchmark), (ii) a naïve Bayesian network (BN) where the conditional probabilities that define the relations between Db and explanatory landscape variables were derived from expert knowledge rather than data and (iii) a 'hierarchical' BN where model structure was also defined by expert knowledge. These models were used to generate spatial predictions for mapping topsoil Db at a landscape scale. The results show that expert knowledge-based models can identify the same spatial trends in soil properties at a landscape scale as state-of-the-art mapping algorithms. This means that they are a viable option for soil mapping applications in areas that have limited empirical data