Sphagnum Moss

Many species of sphagnum can hold up to twenty times their weight in water. As sphagnum grows, it accumulates empty, dead cells, which hold water. The spaces between leaves also hold water. 

Sphagnum is an important actor in water regulation because of this ability. Sphagnum absorbs rainwater and gradually releases it, which inhibits erosion and decomposition. Sphagnum also limits access to nitrogen in the soil, further inhibiting decomposers. When dead plant material accumulates in an area with sphagnum, it becomes a sphagnum wetland with a rich peat deposit. 

Irish peat bogs have a strong connection with Celtic mythology. It takes a peat bog thousands of years to create the peat, which can be used for fuel when dried. They are also important for biodiversity, especially for Ireland’s wetland species. “Bog bodies” refers to bodies preserved by the peat bogs, which are anaerobic and highly acidic. Peat bogs essentially mummify these bodies and, in addition to inspiring folklore, these bodies supply valuable archaeological information into the lifestyles of Irish people from the distant past.

Sphagnum, as a crucial and large component of peat bogs, also plays an important role in carbon cycling. Peatlands sequester significant amounts of carbon; in response to rising global temperatures, peatlands release carbon dioxide into the atmosphere, which triggers further rises in temperatures and accelerates the loss of peat-sequestered carbon into the atmosphere. 

Sphagnum in peat bogs also host microbial communities involved in carbon and nitrogen cycling. Global warming causes sharp declines in biodiversity in these microbial communities, which leads to a decrease in nitrogen fixation rates. Nitrogen fixation converts atmospheric nitrogen into a form that other organisms, such as plants and animals, can use. Lower biodiversity and nitrogen fixation rates in peatlands also affects the productivity of the ecosystem and potential for carbon sequestration; in many ways, the degradation of peatlands and its subsequent ecological effects is a positive feedback loop, or self-reinforcing cycle.

Peatlands’ and within them, sphagnum moss’, health and viability are key to a healthy ecosystem and planet; their protection is a key element in any well-crafted plan for combating the effects of global warming. Whether we use them as food or fuel, stores of important historical artifacts or sources of fixed nitrogen, peat bogs are multi-talented and fascinatingly unique microbiomes.