Competition for agricultural land
The amount of land that could be dedicated to energy biomass is limited as most of the suitable land is in use for agriculture, human settlement, covered by forests, or locked up in protected areas (FAO, 2003). Therefore, energy biomass plantations may compete with the existing agricultural land uses and/or may lead to the use of the remaining natural landscape that should be kept under conservation.
A study from the University of Florida suggests that to replace the entire US gasoline supply would require 60% of all available cropland (Moreira, 2005). It is also estimated that up to 13% of the European Union agricultural land would be needed to produce the 5.75% target of biofuel share in Europe’s energy consumption (Biofuels Research Advisory Council, 2006).
The consequence of energy biomass plantations expanding into the natural landscape will obviously lead to direct biodiversity loss due to habitat destruction and fragmentation. Further biodiversity loss would occur if unsustainable agricultural practices (e.g. overuse of chemical inputs that may lead to eutrophication and water pollution, tillage that can result in soil erosion or compaction) are used when establishing and managing the planted biomass. However, Perlack et al. (1992) and Cook and Beyea (2000) reported that displacing annual crops with perennial grassy crops, considered as a second generation feedstock, could reduce pesticide and net fertilizer use, and lead to greater animal biodiversity as habitat is improved and natural ecosystems functions are restored.
Other issues related to agriculture include: (i) monoculture of the more energy efficient crops (sugar cane, oil palm) may eventually be preferred over crop rotations, which may result in the simplification of agro-ecosystems associated with a decrease in crop and farm biodiversity; (ii) the emergence of genetically engineered energy crops for better yield and energy efficiency could result in cross-pollination in the wild, thereby affecting biodiversity.