Perennial energy crops and biodiversity could be benefitial for fauna in metal contaminated soils, said a very recent article published in Biomass and Bioenergy Journal (Feb 2014). 

The article focused on an arthropod called “Collembola” and comparisons between switchgrass, misncathus and wheat agro-ecosystems. Authors wrote:

Collembola hexapods in soil: In sheer numbers, they are reputed to be one of the most abundant of all macroscopic animals, with estimates of 100,000 individuals per cubic meter of topsoil, essentially everywhere on Earth where soil and related habitats

To meet the EU production target (+10% by 2020) for renewable fuel, will require allocating vast quantities of agricultural land to growing bioenergy crops, in majority perennial nonedible grasses. This, while there already appears to be little chance of the world’s current arable acreage being sufficient to produce enough food to meet rising future demand. Consequently, a renewed interest in looking for areas degraded by human activities as possible sources for bioenergy crops establishment has emerged. Agriculture for biomass energy can move into such abandoned land that does not have competing uses and. For example, soils of contaminated agrosystems represent potential arable land surfaces for the production of non-alimentary crops, providing that such cropping systems do not lead to increased risks for the environment. In the case of contaminated agricultural soils, there remains a critical need for empirical data on the consequences of implementing new agroenergy productions systems on biodiversity conservation, especially on belowground fauna.

The author’s hypothesis was that biomass crop establishment on contaminated soils allows for belowground diversity to increase by modifying important niche parameters such as food availability and quality or microhabitat conditions.

Perennials can provide straw in a much more sustainable way

Perennials can provide biomass straw in a much more sustainable way since operations take place only once a year and several organisms in soil, water and air, can improve their life cycles and reproduction.

In this article, “soil collembolans have been shown to be sensitive to the establishment of bioenergy crops on polluted soils with a strong increase of abundance and diversity compared to annual wheat crops”. The identity of bioenergy crops is a critical factor driving the composition and structure of collembolan communities which might have far-reaching consequences for microbial processes and reproduction of fungi and bacteria, including potential pathogens. Finally, on contaminated land the inclusion of perennial bioenergy crops seems to have the potential to increase belowground faunal diversity and abundance.

Current monocultures and abandoned lands worldwide are sometimes subject of wrong measures and management by farmers and public organizations. Several studies confirm that managing grasslands and perennials can be clearly benefitial to maximized the productivity in the long term and this is compatible with an increased biodiversity in the ecosystems.