The rainforest consists of several layers. Each layer has plants and animals which are adapted to the conditions found there. In the ground layer, soil is poor and any nutrients are quickly recycled. The next layer is made up of shrubs and plants which can tolerate low light levels. The lush undercanopy consists of smaller trees which compete for the light and space. Epiphytes are found in the undercanopy.
In additon. biofuels may be marketed as good, renewable, sustainable or next generation, partly for promotional purposes. So achieving a widely accepted definition of advanced and/or sustainable biofuels is a challenge. Often the term is applied to biofuels produced from lignocellulosic (LC) or cellulosic biomass.io-oil can be used as a heating fuel or can be further converted to advanced biofuels. Torrefaction (heating at 200-300 Â°C in the absence of oxygen, at atmopsheric pressure) converts biomass to bio-coal, which can be more easily used for power generation than untreated biomass.
Biofuel is renewable because the process that generates the fuel is ongoing. Trees can be regrown, sewage can be converted into methane, and oil and alcohol can be generated from various plants. Biofuel takes carbon dioxide from the air as the original vegetation grows, and returns it when burnt, so it has a neutral carbon footprint.