The use of earthworms in ecological soil classification and assessment concepts
Rombke, J. ; Jansch, S. ; Didden, W.A.M. - \ 2005
Ecotoxicology and Environmental Safety 62 (2005)2 sp. iss.. - ISSN 0147-6513 - p. 249 - 265.
ecosystem engineers - southern sweden - heavy-metals - forest soil - populations - lumbricidae - oligochaeta - organisms - profiles - invertebrates
Without doubt, earthworms are the most important soil invertebrates in most soils worldwide, in terms of both biomass and activity. Several species are even considered to be ecosystem engineers. Earthworms are also known to influence soil structure, soil chemistry, and, in particular, processes like organic matter decomposition. In addition, standardized sampling methods are available and their taxonomy is well known (even the first PC-aided keys have been developed). For these reasons, earthworms were recognized as a part of ecological classification and assessment schemes early on. However, due to the relatively small number at many sites, they have to be part of a battery approach. By use of examples from The Netherlands (biological indicator of soil quality) and Germany (soil biological site classification), the practicability of the use of earthworms is demonstrated in determining the influence of different anthropogenic land use forms. In these cases, the structure of the earthworm community, as well as their abundance and biomass, were used as endpoints.
Improved recruitment and early growth of Scots pine (Pinus sylvestris L.) seedlings after fire and soil scarification.
Hille, M.G. ; Ouden, J. den - \ 2004
European Journal of Forest Research 123 (2004)3. - ISSN 1612-4669 - p. 213 - 218.
natural regeneration - southern sweden - northern sweden - clear-cut - boreal - forest - stand - establishment - germination - understory
The success of seedling recruitment of Scots pine (Pinus sylvestris L.) is strongly dependent on soil surface properties, such as humus depth and moisture content. In an undisturbed forest floor, seedlings are seldom able to become established due to the high incidence of desiccation in the organic soil layer. Methods that remove the organic soil layer are often necessary to improve the availability for radicles to reach the more stable moisture regime in the mineral soil. In this study we investigated pine-seedling establishment after mechanical soil scarification, burning of litter (OL) and burning of litter and humus (OL and OFH) in two mature pine stands in Germany. The herbaceous layer of the first stand was dominated by grasses (Molinia caerulea L. and Deschampsia flexuosa L.), whereas the herbaceous layer of the second stand was dominated by blueberry (Vaccinium myrtillus L.). Pine seeds were placed in experimental plots, and seedling numbers and heights were recorded at regular intervals. All treatments that removed organic soil resulted in higher seedling counts than did the undisturbed forest floor. The highest seedling counts were found on scarified and severely burnt plots, whereas seedling counts were lower on lightly burnt plots. Seedlings were significantly taller on burnt plots. This study shows that pine regeneration is stimulated by fire, not only in boreal forests, but also under central European conditions. With the expectation of higher fire frequency in the near future due to climatic changes, natural regeneration and succession on burnt sites should receive more focus in forest management and research.
Introduction to the special issue on experiences with the impact and prevention of subsoil compaction in the European Union
Akker, J.J.H. van den; Arvidsson, J. ; Horn, R. - \ 2003
Soil & Tillage Research 73 (2003)39479. - ISSN 0167-1987 - p. 1 - 8.
sugar-beet harvesters - southern sweden - crop yield - soil - displacement - vehicles
The papers in this special issue present results of the European Union (EU) concerted action ¿Experiences with the impact of subsoil compaction on soil crop growth and environment and ways to prevent subsoil compaction¿. The results and conclusions of earlier research on subsoil compaction are memorized and it is emphasized that the conclusions are still sound: high axle load traffic on soils of high moisture content causes deep and persistent subsoil compaction. The concerted action on subsoil compaction in the EU and an almost identical concerted action on subsoil compaction in central and eastern Europe are briefly introduced. This special issue presents a selection of papers of the concluding workshop of the concerted action on subsoil compaction in the EU. It includes three papers on modeling the impact of subsoil compaction on crop growth, water availability to plants and environmental aspects; three papers on modeling of subsoil compaction by heavy machinery; four papers on measurement of soil mechanical and physical properties in relation to subsoil compaction and four papers on methods to determine the risk of subsoil compaction and to identify prevention strategies. The trends in agriculture in relation to subsoil compaction are discussed. A positive trend is that policy makers in the EU and worldwide recognize soil as a vital and largely non-renewable resource increasingly under pressure. A negative trend is that wheel loads in agriculture are still increasing causing severe damage to subsoils. The conclusion is that European subsoils are more threatened than ever in history. Manufactures, agricultural engineers and soil scientists should collaborate and research should be initiated to solve this problem and find solutions. Subsoil compaction should be made recognized by all people involved from farmer to policy maker. Therefore an assessment of the existence and seriousness of subsoil compaction throughout Europe should be initiated.