Cyathea australis pinnae
The pleasures of fern-seeking
Seeing how the fern flora relate to the over-canopy and the other vegetation teaches a good deal about the local soil and climatic conditions. What makes fern-seeking important is the opportunity to document environmental conditions and gain new knowledge about the ecological behaviour of fern species. What makes fern searching interesting, even exciting at times, is finding small pockets of much rarer species, and finding ferns in unexpected places.
In a drought-prone region such as the Southern Tablelands where Canberra is located, any fern that grows must be able to tolerate periods of very hostile conditions. In part this is a measure of the tenacity of the successful species, and to a small extent the capacity of the species to send its spores long distances. An illustration of the latter could be seen in the 1970s in the old quarry on Mount Ainslie in the centre of Canberra. It is the source of a small natural spring, and the ground is permanently damp. Several species of fern had colonised it, including the tree fern Cyathea australis, and the water fern, Blechnum minus. Admittedly, they were not the best specimens, but they are quite unexpected in the dry Bush that surrounds them. There were no other plants of these types within 50 km of the site, so the source of the spores was quite a distance away. Unfortunately, perhaps due to drought or human disturbance, the over-canopy of eucalypts has thinned greatly, and the area now only hosts common bracken, Pteridium esculentum, Cheilanthes austrotenuifolia and, in sheltered places, common maidenhair, Adiantum aethiopicum.
The role of the Amateur
There is endless opportunity for the amateur to find new occurrences of fern species. The vegetation in the more remote valleys in the Brindabellas and the Tidbinbillas has only been explored by professional botanists to a limited degree. It is readily possible for the amateur botanist to discover plant types not previously known in the region. There are unexpected groups of quite rare ferns such as Todea barbara, the King or Tub fern, in the gullies on the lower slopes of the Brindabella Range and the Blue Range further north. These grow very large in places, like thick-set tree ferns. Likewise you can find pockets of the Bat's wing fern, Histiopteris incisa.
The job of finding and mapping these rare plants is usually left to professional scientists in the universities or national parks authorities. And there are numbers of scientists in these organisations who do carry out this work. But the vastness of the job of surveying even a small area like the Canberra Region is daunting for the small number of trained scientists. Expecting them to focus on one genus is even less reasonable. This is where the botanically aware amateur can play an important role. The process of walking the valleys and ridges, of noting the occurrences of plants, can provide valuable data for ecological surveys. Such surveys assist the authorities to make the conservation decisions that can preserve these beautiful places.
Perhaps the greatest value that the amateur botanist can contribute is to seek out the special places that are in greatest need of protection, that may perhaps have been missed by the professionals.
There is great value in the amateur making contact with the professionals. Apart from the opportunity to learn about the ecology of the region, the amateur can also gain official approval for access to places normally off limits to the public. Of course, you have to establish a reputation as a careful observer before this is likely to happen, but it can build a strong bond between those who appreciate nature and those whose job it is to protect it.
In an area like Canberra, these fern-lined creeks are places to be cherished. But despite their rarity, the tree fern groves in the mountain gullies are not always as protected as might be expected. The Cotter Valley and the Tidbinbillas and Brindabellas are national parks, but there are other areas that have high conservation value that are afforded no such protection. This can occur when the commercial imperatives of forestry clash with the needs of conservation. There's a sad tale to be told here, as you will see later.