Threats to Cryptogams
In Australia lichen-covered rocks are common in many pastures, grasslands and open forests. At times rocks are indiscriminately collected from such areas, and sold as bush rocks or mossy rocks, for garden use. Many rock-inhabiting lichens, especially the foliose species, do not survive if the rocks are moved. Moreover, some lichens are known only from rocks in waste habitats such as pastures and grasslands.
These rocks in open grassland support a rich lichen community dominated by species of Xanthoparmelia.
A pilot study into Tasmanian roadside species found over 80 species of lichens and bryophytes in a 50-metre section of a roadside verge. Interestingly the investigators found several lichen species that either had not previously been known from Tasmania or which had been considered rare. Various studies into flowering plants in roadside reserves have shown that such areas are often important refuges for plants and it is likely that the same is true for lichens and bryophytes as well. Unfortunately such areas are often parked on, get rubbish dumped onto them or are damaged during roadwork.
Roadside verges are often overlooked as habitats for cryptogams.
There is still much to learn about the Australian lichens and bryophytes from what species we have to their biology and ecology. This means that land managers often lack the information to allow them to properly include lichens and bryophytes in land management decisions.
For example, while many areas with a high conservation value for flowering plants may also have a high value for lichens and bryophytes, the reverse is not always true. Areas of degraded grasslands with no conservation value when it comes to flowering plants may still be rich in lichens and bryophytes. Ignorance of the environmental importance of lichens and bryophytes means that such areas may be overlooked during conservation assessments.
Fire and Trampling
Occasional fires probably do little damage to the populations of many lichens or bryophytes, but frequent burning can destroy the lichen and bryophyte diversity of an area. Excessive trampling, whether by humans or by overstocking with animals, damages lichens and bryophytes as well as vascular plants. In particular, the lichen and bryophyte soil crusts in arid areas are very susceptible to overstocking and these crusts recover very slowly.
Xanthoparmelia versicolor, a foliose lichen which grows on the ground in arid areas.
Whats Being Done?
Environment Australia, the Commonwealth Department of Environment and Heritage, has recognised the lack of knowledge about our lichens and bryophytes as a target area for future research. A national conservation overview of these organisms was published in 1997. The Australian Biological Resources Study (ABRS), which is part of Environment Australia, is funding the production of books and electronic keys describing the species known in Australia.
Many land care organizations are increasingly stressing the importance of lichens and bryophytes in revegetation work. An example of such an organization is the Australian Network for Plant Conservation (ANPC). ANPC has a very diverse membership, ranging from individuals to local community groups, government departments, business groups and conservation agencies, all interested in helping to save Australias native plant heritage. ANPC promotes awareness of lichens and bryophytes through its newsletter Danthonia and through conservation workshops for the general public.
Understanding the importance of cryptogams in our ecosystems is vital to conserving the health of our environment. More surveys and environmental studies are needed and suitably trained scientists need to be encouraged to work in this field. Greater public and scientific awareness and appreciation of these important organisms is basic to sound land management practices in the future.
Finally, in its advice on revegetation, Bushcare Tasmania reminds people that: