Search results for "soil"
showing 10 items of 3493 documents
Distribution of soil animals in patchily contaminated soil
1996
Abstract Distribution of soil animals with respect to patchy chemical contamination was studied in microcosms containing reconstituted coniferous forest floor. Soil materials were defaunated and soil organisms were reinoculated into a mesh basket in the centre of each microcosm. Part of the humus layer was contaminated with three concentrations of sodiumpentachlorophenate (0, 50 or 500 mg PCP kg −1 of dry humus) and put into mesh baskets (two per concentration) around the central patch. No differences in dispersion ability from the reinoculated patch were found between microarthropod species. PCP decreased microbial biomass in the humus. Numbers of collembolans were significantly lower in t…
Oribatid mites (Acari: Oribatida) in boreal forest floor and decaying wood
2008
Summary We studied the oribatid mite communities in forest floor and in decaying wood in pine (Pinus sylvestris), spruce (Picea abies) and deciduous (mainly Betula pendula and B. pubescens) forests at different latitudes in Finland. The study sites were either in mature managed forests or in old-growth forests in nature reserves. Altogether 78 sites were sampled in 2004 and 2005, yielding a total of 38,145 oribatid mites belonging to 133 species, of which four were new to Finland. Oribatid mite communities differed in terms of total number and community structure between forest types and latitudes within the boreal forest zone. The most abundant and diverse communities were in spruce forest…
Sensitivity of soil processes in northern forest soils: are management practices a threat?
2000
Abstract There is evidence that forest management practices influence soil-decomposer communities. It is also established that changes in the trophic structure and composition of these communities can induce changes in soil-nutrient dynamics, thereby affecting plant growth. Whether forest productivity is affected by management-induced changes in, e.g. soil faunal structure, is, however, yet to be shown. The aim of this study was (1) to determine the resolution of the ecological hierarchy (e.g. species, functional groups, trophic levels) at which a change in soil fauna would alter biotically-controlled processes in soils, and (2) to examine the sensitivity of soil fauna of the boreal forest …
Habitat patchiness affects decomposition and faunal diversity: a microcosm experiment on forest floor.
1998
Environmental heterogeneity has been intensively studied, but little is known about relationships between habitat patchiness and soil processes. The aim of this study was to investigate (1) the impact of patchiness of the litter layer on the decomposer community and litter decomposition rate, and (2) whether the impact of soil fauna on the rates of processes differs in relation to patchiness. An experiment was carried out in microcosms with coniferous forest humus and four kinds of litter with different C:N ratios or stages of decomposition, either separately (i.e. in patches) or mixed with each other. Microarthropod species diversity was better maintained in the patchy systems. In the abse…
Short-term responses of soil decomposer and vegetation communities to stump harvesting in boreal forests
2011
Recently, in addition to logging residues, stumps have become an important component in energy production since there is growing global interest in the use of renewable energy sources in order to decrease anthropogenic carbon emissions. Harvesting of stumps influences the forest floor by changing vegetation and soil organic layers and exposing mineral soil across large areas. We studied whether stump harvesting after clear felling poses further short-term changes in boreal forest soil decomposer community (microbes and mesofauna) and vegetation when compared to the traditional site preparation practice (mounding). In general, stump harvesting caused decline in enchytraeid abundance but did …
Laboratory design to simulate complexity of forest floor for studying the role of fauna in the soil processes
1990
We developed a technique for simulating the complexity of the soil system under controlled laboratory conditions. Removable microcosms were inserted in a homogeneous substrate soil in a large plastic box. This macrocosm was sealed, except for an inlet and outlet for air flow, and an aperture for collecting leachates. The system can be designed and manipulated in various ways according to the needs of a particular experiment. Respiration and nutrient fluxes can be measured either from the whole macrocosm or separately from the microcosms. We have performed three experiments in order to evaluate the role of animals in the soil processes. A set of macrocosms was constructed from components of …
Role of the fauna in soil processes: techniques using simulated forest floor
1991
Abstract Laboratory experiments were conducted to test the influence of soil animals on processes such as decomposition, nutrient cycling, and plant growth in northern coniferous forests. The techniques included simulation of a complex pattern of forest floor, controlled air flow through the systems, and automatic measurement of carbon flows. The soil fauna generally enhanced evolution of CO2 and mineralization of N and P from soil and litter, and increased considerably the biomass production and N content of birch seedlings. Significant results were also obtained on interactions between different faunal components.
Spot mounding and granulated wood ash increase inorganic N availability and alter key components of the soil food web in clear-cut Norway spruce fore…
2012
Abstract The interactive effects of site preparation (spot mounding) and fertilization (granulated wood ash) on soil properties, soil micro- and mesofauna and ground vegetation were studied in two Norway spruce plantations established in clear-cut forests in Central Finland. Half of the seedlings were planted on mounds created by the planting machine, and the rest on intact forest floor. Half of the seedlings on mounded and intact forest floor were fertilized by adding granulated wood ash to circular plots surrounding the seedlings. Initial samples were taken from mounded and intact soil immediately after planting in June. Samples were taken from all treated plots in the autumn in the first…
Soil macroarthropod communities in planted birch stands in comparison with natural forests in central Finland
2002
The aim of the study was to compare the soil macroarthropod communities in anthropogenous birch stands of different origin with each other and with natural forests at the same latitude in Finland. A total of nine forest sites was investigated: three birch stands (Betula pendula) planted ca. 30 years prior to the study after clear-cutting of spruce stands (“Birch after Spruce”, BS), three birch stands planted ca. 30 years earlier on arable soil that had been under normal cultivation until reforestation (“Birch after Field”, BF), and three “Natural Deciduous” (D) forests. These were sampled three times in 1998, animals were extracted with large Tullgren funnels, counted per square metre, and …
Distribution of sulphur forms in soils from beech and spruce forests of Mont Loz�re (France)
1993
From a quantitative inventory of sulphur forms and sulphur budget, the relation between the distribution of the various sulphur forms and the sulphate fluxes in three soil profiles has been addressed. These profiles are located in two forested watersheds at Mont Lozere. One has been sampled in a beech forest and the other two in a spruce forest and in a harvested plot of this spruce forest, respectively. The mean annual input-output budgets showed a sulphur immobilization in the soil cover of the three plots. In the preserved spruce forest plot, because of larger dry depositions, the sulphur immobilization is much greater than in other plots and occurs essentially in the B horizons. In the …