Soil systems ecological impact

A Semi-quantitative Approach Erosion and Deposition. Over the centuries the primary impact of human activity has been to deforest the surrounding countryside and increase the rate of erosion and deposition into rivers. This results primarily from the destruction of vegetation cover which stabilizes soil systems on gradient. The ecological impact of erosion has at present reached catastrophic proportions. The magnitude of continental erosion into rivers is illustrated in Figure 3. 

PAHs are widely distributed in the environment as evidenced by their detection in sediments, soils, air, surface waters, and plant and animal tissues. However, the ecological impact of PAHs is uncertain. PAHs show little tendency for bioconcentration despite their high lipid solubility (Pucknat 1981), probably because most PAHs are rapidly metabolized. Sims and Overcash (1983) list a variety of research needs regarding PAHs in soil-plant systems. Specifically, research is needed to establish the rates of PAH decomposition in soils the soil PAH levels above which PAH constituents adversely affect the food chain and enhancement factors that increase degradation rates of PAHs, especially PAHs with more than three rings. Once these factors have been determined, PAH disposal into soils may become feasible at environmentally nonhazardous levels. 

Keel, C., Ddfago, G. Interactions between beneficial soil bacteria and root pathogens mechanisms and ecological impact. In, Multitrophic Interactions in Terrestrial Systems. Gange A.C., Brown, V.K. eds. Blackwell Science Ltd. London, UK, 1997 pp. 27-46. 

The ecotoxicological data reviewed in this section show that TNT contamination of soil can disrupt the ecological functioning of a soil system and inhibit natural attenuation processes. This occurs because TNT can destroy a portion of the soil microbial community involved in OM decomposition and reduces the amount of soil Corg produced by this community. Consequently, the amount of bioavailable TNT is relatively high and it interferes with colonization of impacted areas by plants, resulting in toxicity of TNT to soil invertebrates and adversely affecting site remediation and... 

Exploration activities are potentially damaging to the environment. The cutting down of trees in preparation for an onshore seismic survey may result in severe soil erosion in years to come. Offshore, fragile ecological systems such as reefs can be permanently damaged by spills of crude or mud chemicals. Responsible companies will therefore carry out an Environmental Impact Assessment (EIA) prior to activity planning and draw up contingency plans should an accident occur. In Section 4.0 a more detailed description of health, safety and environmental considerations will be provided. 

Ferris, H., Venette, R.C. and Lau, S.S. 1996. Dynamics of nematode communities in tomatoes grown in conventional and organic farming systems, and their impact on soil fertility. Applied Soil Ecology 3 161-175. 

For the implementation of a land use category in the ISO methodological framework of LCI, several category indicators have been proposed. Mila i Canals et al. present an overview of currently used indicators of land use quality, differentiating between three impact pathways impacts on biodiversity, on biotic production potential, and on ecological soil quality [19]. They also discuss which kind of information is needed from the inventory to apply the respective indicator, which is considerably more than the simple information for occupation interventions. Mila i Canals et al. [19] also define a transformation impact which represents the difference between a reference state, where land use would not have been changed compared to the actual changes in the system under study. 

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