Can CAM plants be a biofuel world-saver? CAM plants (crassulacean acid metabolism) like many Euphorbia, thrive in arid, marginal country because of their unique photosynthesis adaptations, producing large amounts of biomass for very little water, making them perfect bio-energy crops.
Biofuels have been supplementing the world’s dwindling fuel reserves for some years, but there’s much criticism of how arable food-producing land is now being used for the higher return it gets from producing biofuel.
Academic, engineer and eco-entrepreneur Mike Mason has been studying Ficus opuntia-indica and Euphorbia tirucalli, both CAM plants that grow well in land where the rainfall is either too low or too unpredictable for conventional farming. CAM plants use about 10% of the water needed by other similarly-sized plants as they are able to open their stomates to capture carbon dioxide at night and then store it to use in photosynthesis during the next day’s sunshine. Non-CAM plants have to open their stomates during the day to absorb carbon dioxide, which means they also lose valuable moisture from their leaves.
CAM plants, typically cacti and succulents, are found throughout many of world’s drier regions.
There has been little plant-breeding work done on CAM plants for biogas production, which means there is a huge potential to develop even better plants. Also more work needs to be done to improve the efficiency of anaerobic digestion, although it does produce nutrient-rich water as a bi-product. This water could be used to grow high-protein water plants, like Lemna as a food source for fish sock.
Mason is hoping that by developing biogas production from CAM plants, we could prevent billions of tonnes of carbon emissions, while saving valuable arable land for food production.