A method of establishing a transect for biodiversity and ecosystem function monitoring across Europe

The establishment of the range of soil biodiversity found within European soils is needed to guide EU policy development regarding the protection of soil. Such a base-line should be collated from a wide-ranging sampling campaign to ensure that soil biodiversity from the majority of soil types, land-use or management systems, and European climatic (bio-geographical zones) were included. This paper reports the design and testing of a method to achieve the large scale sampling associated with the establishment of such a baseline, carried out within the remit of the EcoFINDERS project, and outlines points to consider when such a task is undertaken. Applying a GIS spatial selection process, a sampling campaign was undertaken by 13 EcoFINDERS partners across 11 countries providing data on the range of indicators of biodiversity and ecosystem functions including; micro and meso fauna biodiversity, extracellular enzyme activity, PLFA and community level physiological profiling (MicroResp™ and Biolog™). Physical, chemical and bio-geographical parameters of the 81 sites sampled were used to determine whether the model predicted a wide enough range of sites to allow assessment of the biodiversity indicators tested. Discrimination between the major bio-geographical zones of Atlantic and Continental was possible for all land-use types. Boreal and Alpine zones only allowed discrimination in the most common land-use type for that area e.g. forestry and grassland sites, respectively, while the Mediterranean zone did not have enough sites sampled to draw conclusions across all land-use types. The method used allowed the inclusion of a range of land-uses in both the model prediction stage and the final sites sampled. The establishment of the range of soil biodiversity across Europe is possible, though a larger targeted campaign is recommended. The techniques applied within the EcoFINDERS sampling would be applicable to a larger campaign

Ecological network analysis reveals the inter-connection between soil biodiversity and ecosystem function as affected by land use across Europe

Soil organisms are considered drivers of soil ecosystem services (primary productivity, nutrient cycling, carbon cycling, water regulation) associated with sustainable agricultural production. Soil biodiversity was highlighted in the soil thematic strategy as a key component of soil quality. The lack of quantitative standardised data at a large scale has resulted in poor understanding of how soil biodiversity could be incorporated into legislation for the protection of soil quality. In 2011, the EcoFINDERS (FP7) project sampled 76 sites across 11 European countries, covering five biogeographical zones (Alpine, Atlantic, Boreal, Continental and Mediterranean) and three land-uses (arable, grass, forestry). Samples collected from across these sites ranged in soil properties; soil organic carbon (SOC), pH and texture. To assess the range in biodiversity and ecosystem function across the sites, fourteen biological methods were applied as proxy indicators for these functions. These methods measured the following: microbial diversity: DNA yields (molecular biomass), archaea, bacteria, total fungi and arbuscular mycorrhizal fungi; micro fauna diversity: nematode trophic groups; meso fauna diversity: enchytraeids and Collembola species; microbial function: nitrification, extracellular enzymes, multiple substrate induced respiration, community level physiological profiling and ammonia oxidiser/nitrification functional genes. Network analysis was used to identify the key connections between organisms under the different land use scenarios. Highest network density was found in forest soils and lowest density occurred in arable soils. Key taxomonic units (TUs) were identified in each land-use type and in relation to SOC and pH categorisations. Top-connected taxonomic units (i.e. displaying the most co-occurrence to other TUs) were identified for each land use type. In arable sites this was dominated by bacteria and fungi, while in grassland sites bacteria and fungi were most connected. In forest soils archaeal, enchytraeid and fungal TUs displayed the largest number of neighbours, reflecting the greatest connectivity. Multiple regression models were applied to assess the potential contribution of soil organisms to carbon cycling and storage and nutrient cycling of specifically nitrogen and phosphorus. Key drivers of carbon cycling were microbial biomass, basal respiration and fungal richness; these three measures have often been associated with carbon cycling in soils. Regression models of nutrient cycling were dependent on the model applied, showing variation in biological indicators