Soil biota play fundamental roles in delivering key ecosystem goods and services of soils and are both directly and indirectly
responsible for delivering many important soil functions such as soil organic matter (humus) formation, realising nutrients from
soil organic matter, forming and maintaining soil structure and contributing to water storage and transfer in soil.1
Because of the organic matter of soils is one of the largest carbon pool, humus formation is extremely important to CO2 sink.
The good quality soil is as important and as valuable as clean air or clean water.
Soil degradation, therefore, is a serious threat, which the European Union is facing. In addition, the level of threat is continuously
increasing due to global warming, inappropriate land use (overgrazing, over-exploitation, over-irrigation, etc.) and river regulations.
Soil organisms are responsible for supplying the environment with a number of critically important ecosystem services:
However the knowledge on the function performed by soil biota is still very limited.
Here there are some aspects of the decline of soil biodiversity in view of other soil threats.
- Soil formation
- Decomposition of organic matter
- Soil fertility and plant growth
- Water infiltration and retention
- Degradation of pollutants
Climate change, by the mean of temperature and precipitation variations in time and space,
will play a major role among soil biodiversity threats.
Land use change and the consequent habitat and ecosystem disruption, is probably the main threat on biodiversity.
- There is a need to predict the alteration of soil biodiversity patterns due to global climate change.
- Researches in the extreme environment can provide important information on the effect of climate change on soil biodiversity and ecosystem function.
- Experimental results from extreme environment demonstrated that the temperature rise determine an increase in bacteria,
fungi and nematode density, but a reduction of biodiversity.
Soil erosion affects managed and natural ecosystem, and the consequences of this process on soil biodiversity will be both direct and indirect.
- Among soil biota the greatest effects will be seen more quickly on soil macro and mesofauna.
Soil compaction: the use of heavy load machinery in agriculture and the reduction in soil organic carbon content can determine soil compaction
- The direct effect of soil erosion consists in the removal of soil biota and its habitat.
- The indirect effects are played through the vegetation regulation.
Soil biological activity and diversity is important in all habitat types and all soil types, therefore the prototype will be tested all main soil types
occur in Hungary and relevant in Europe (except podsols and related soil types in North Europe)(see additional details in question 14. concerning
procedures in Action 3. and Action 4.). Concerning use of the prototype coarse sandy soils seem to be the only questionable ones, because the sand
particles dropping to the traps make overestimation. These sand particles are counted electronically as being soil microarthoropods. In the improvement
of mechanical part in Action 2 we will find a mechanical solution for this problem.
- High soil bulk densities affect root penetration, soil pore volume, water infiltration and air permeability, and thus,
finally the pore space habitable for soil organisms and the soil environmental conditions.
- The effects of soil compaction are not the same among the different groups of soil organism,
but in general the process led to a reduction or a modification of soil biodiversity.
- It also can move the soil toward anaerobic conditions, which change the types and distribution of soil organisms in the food web.
In order to preserve good quality soils, experts need to know when, where and how they should interfere in to negative processes.
For such an interaction up-to-date, good quality data possibly on large-scale are indispensable.
European Union (6th EAPís Thematic Strategy for Soil) and national environmental policies for soil protection need precise and accurate
data on field or landscape level to check environmental status and performance. For example, mapping polluted areas, or following changes in
soil quality are main tasks in environmental protection. However, recently there is not any cost-effective and reliable method for assessing
soil quality on large scale. None of the methods used today is able to provide such set of data because they are whether time-consuming,
expensive or unreliable. Although, using soil biological activity indicators is one of the possibilities to reduce the very high costs of
delineation in remediation actions. measuring soil biological activity is labour-intensive, needs special experts and provides unreliable data.
Due to the high spatial and temporal variability of soil organisms low precision comes from inadequate sampling tool and design.
1 Bardgett, R.D., Hopkins, D.W. and Usher, M.B. (2005) Biological Diversity and Function in Soils.
Cambridge University Press.