Biomass recovery from invasive species management in wetlands

Reed represents an opportunity fuel that can be obtained from wetland restoration activities designed for reducing the dominance of invasive reed over native matrix vegetation. Equipment used for reed recovery must be light enough to negotiate soft terrain. At the same time, it needs to be versatile, so that investment cost is depreciated on a variety of different tasks, given the seasonal character of reed collection. The study tested a new system designed for harvesting reed during winter, under unfrozen soil conditions. This system was based on a modified snowcat (trail groomer) and on light orchard tractors, for maximum floatation. Reed chopping, windrowing, baling and extraction took 12 h ha-1 and incurred a cost of 500 EUR ha-1, or 111 EUR t-1 dry matter. Assuming that reed biomass would obtain a price of 80 EUR t-1 dry matter, the cost of reed control would amount to 160 EUR ha-1, which is better than the 242 EUR ha-1 required for chopping to waste. Furthermore, savings can be accrued by better operator selection (baling) and by improving extraction technique, which would bring reed collection cost below 100 EUR ha-1. Reed biomass has favourable fuel qualities, including low water mass fraction. For this reason, reed can be used to build a strategic reserve to be tapped in winter, at times of peak demand. Furthermore, reed grows on land that is not suitable for other uses, and therefore it is unlikely to compete with food crops.