Harvesting reed (Phragmites australis): Possibilities, challenges, and considerations for coastal ecosystems and feed production

Reed (Phragmites australis) is an emergent macrophyte with a global distribution. Reed stems form beds which provide food and shelter to many different organisms. However, symptoms of anthropogenic development such as species introductions and eutrophication have led to conditions in which reed is either invasive or expanding within its native range at the expense of biodiversity. Solutions are therefore desirable by which reed invasion and expansion can be controlled.
One common solution is the physical removal of reed, which has the added benefit of producing a usable material as a by-product and removing nutrients from potentially eutrophic environments. Utilisation of this by-product could offset costs, increasing management feasibility. One use, as a feed for livestock, is uncommon despite the suitable nutritional composition of reed. Demand for livestock feed is rising while supply can be limited by increasingly common floods and droughts. Reed is flood and drought-tolerant, and increasing in supply, and so could help meet increasing demands. Limited studies of reed intake and digestion may explain why it is not a common feed. Furthermore, while the effects of reed management on the environment are well studied, few studies investigate the effects of reed harvesting specifically for resource production. This thesis aims to fill these knowledge gaps.
Results suggest that habitat heterogeneity is a key determinant of reed management benefit to coastal ecosystems, although harvesting that creates a homogenous habitat did not have any detrimental effects on biodiversity.
Further results indicate that reed silage has the potential to be a suitable feed for horses with low energy requirements and dry cows, although measures to improve intake may be required. Reed harvested earlier in the summer was seemingly more suitable for livestock feed than reed harvested later in the summer.
A system in which demand for livestock feed can subsidise coastal management seems plausible, although future studies of methods to improve intake, or optimal yield-habitat heterogeneity trade-offs would address the existing bottlenecks.