Ecological Consequences of Biofuels

Boca Raton

2010

S. 63-92

Artikel aus einer ZeitschriftUnselbständiges Werk

200161713

Removal of crop residues, for example, to produce cellulosic ethanol, can entail a long-term decline of SOM. this is obviously an usustainable practice. It compromises soil functional integrity and may trigger adverse effects such as increased run-off and erosion. These impacts are strongly dependent on crop types, soil properties, and climatic conditions of a specific location. With continued use, soils become more compacted and do not have time to recover. As a result they will not be sustainable for long-term agricultural growth for bioenergy or fuel production purposes. High levels of compaction severely inhibit plant growth and negatively affect biomass productivity, GHG emissions, and sustainability. To reduce the negative and additive compaction effects, permanent havesting lanes must be established. GHG balances of biofuel production systems are heavily influenced by soil deterioration, nitrogen use efficiency, and by-products for additional uses such as feedstuffs. Future biofuels are expected to be produced from cellulose and lignin; this means most parts of the plants grown for fuel production will be utilized. Therefore the areabased yields from curent production. The target compounds contain little nitrogen, and it is expected that N fertilizer rates can be kept low. However, because fuel crops cannot be produced on current agricultural sites best suited for farming and critical to filling future food needs, it remains to be seen whether optimizing yields would lead, as in classical agriculture, to over-fertilization to an extent that will offset expected improvements in the GHG balances of biofuels of the second generation. Some relief of the pressure on soils from an ecological view may come from a third generation of biofuels-microalgae that can produce up to 50.000 liters lipid ha-1yr-1 compard with only 2,400 liters from high yield oil plants. the effects of biofuel production on soil organisms depend on (1) the siting of the biofuel production system and whether it involves land use change, (2) the nature of the biofuel crop; mixed grasslands and diverse forests are more beneficial to soil organisms than any monoculture, and (3) land use intensity and management techniques, some of which can reduce adverse effects on soil biota and promote biodiversity. Considerable problems many arise from impacts on game animals. Wild boar many continue to spread and further proliferation of populations are likely. Damage to crops, inhibition of effective hunting by sheltering wild boar, and increases of compensation payments must be considered.