Erioderma pedicellatum, commonly known as the Boreal felt lichen, grows on trees in the damp boreal forests along the Atlantic coast. It is also one of the most endangered lichens in the world. A new study, published in Botany, uses population models to determine the survival and future viability of the species. The findings show that without increased protection and conservation efforts the Boreal felt lichen population in Nova Scotia will decline by 49% within 25 years.

"Like many lichens, the Boreal felt lichen is an ideal bioindicator, giving us insight into the health of the ecosystem," says Robert P. Cameron, an Ecologist at Nova Scotia Environment and lead author of the study. "The Boreal felt lichen is very sensitive to human impacts on the environment and our research shows that the Atlantic population is declining. This tells us that there are continuing human impacts to the environment despite conservation efforts," continues Mr. Cameron.

The Atlantic population of the Boreal felt lichen is protected under the federal Species at Risk Act (SARA). The species is also critically endangered internationally and is listed as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and critically endangered by the International Union for Conservation of Nature (IUCN).

The federal listing was over ten years ago and despite conservation efforts the population is still declining, partly as a result of air pollution in the form of acid rain and acid fog. A decline in available habitat is also affecting the species, with a loss of mature forests in the area as well as a decline in habitat quality because of nearby developments for roads and forestry.

"One of the main reasons for the decline is that little is known about how this species interacts with their environment," says Mr. Cameron. "A better understanding of the population structure, reproductive rates, and chances of survival through its lifetime is essential in identifying the main causes of the decline and will assist in ongoing conversation efforts," continued Mr. Cameron.

"Our research suggests that conservation efforts focus on adult survival which means more actively protecting the areas where adults commonly grow from forestry and other developments that would alter the moist micro-climate required by this lichen."

This research also highlights the importance of long-term monitoring of lichens as there are very few studies that include data from a decade of detailed and careful monitoring. This approach can reveal trends in populations over longer periods that may not be detectible with shorter term studies. It is important for assessing threats that act on species over long periods of time such as climate change, landscape changes or air pollution.

Long-term data also provides a more accurate assessment when predicting future trends in populations. Although current conservation efforts for this and other species are important, clearly more needs to be done and it needs to be done quickly before we lose this species and the many species associated with it.

The paper, "Population Decline of Endangered Lichen Erioderma pedicellatum in Nova Scotia, Canada" by Robert Cameron and Brad Toms was published in Botany.