Australasian Plant Conservation
Originally published in Australasian Plant Conservation 15(4), March - May 2007
From the Editor: introducing 'What lies beneath?'
Co-ordinator, Editorial Team, Australasian Plant Conservation, Royal Botanic
This issue focuses on the theme of the recent
National Forum on the topic of 'What lies beneath? The role of soil biota in the
health and rehabilitation of native vegetation.'
The Forum concentrated on the soil biota
traditionally classified as plants (the blue-green algae, fungi, lichens,
mosses, liverworts and hornworts). These share usually small to microscopic size
and are often referred to as 'non-vascular plants', 'lower plants' or
'cryptogams'. In fact they belong to a number of the kingdoms of living things:
blue-green algae are bacteria (cyanobacteria), fungi comprise a separate kingdom
(which also includes lichens), and the bryophytes (mosses, liverworts and
hornworts) are plants. This taxonomic diversity is indicative of their varied
and vital roles in ecosystems, such as decomposition of organic matter,
partnerships with plants through mycorrhizas, and formation of biotic soil
Among many very interesting pieces of information in
Forum presentations, David Eldridge pointed out that effective rainfall for
rangeland shrubs is increased by run-off from the biotic soil crust that occurs
in the spaces between the shrubs. A report on the Forum appears in this issue,
along with abstracts of papers presented, and there are also several papers in
this issue which are based on Forum presentations. For other articles relevant
to the topic see also previous issues of
Australasian Plant Conservation
on the themes of 'The forgotten flora remembered', APC 14(1) for June-August
2005, and 'Conserving symbioses', APC 15(2) for September-November 2006.
In a thought-provoking paper not presented at the
Forum, but very much on the theme, Andrew Claridge argues for 'Linking the
above-ground to the below-ground' and makes a case for 'why we should be
restoring processes as well as species in our revegetation efforts'. One of the
processes that Claridge highlights is the relationship between plants and fungi
through mycorrhizas (literally 'fungus-roots'). Neale Bougher surveys the
diversity and roles of a specific group of these fungi, the ectomycorrhizal
fungi, that are common in woodlands and forests across Australia. Karl Vernes
discusses another of the processes highlighted by Claridge, the interactions
between mycophagous (fungus-feeding) mammals and ectomycorrhizal truffle fungi.
He makes the point that there are many mycophagous mammals, and considers what
might occur when the mammal community that disperses truffle spores is
depauperate or missing.
It is important not to focus only on plants, but to
consider the full range of interactions among organisms in native vegetation,
and several presentations at the Forum dealt with interactions with animals,
both vertebrates and invertebrates. Several are covered in the printed
abstracts, and in addition Mark Bourne and co-authors describe experiments
assessing the beneficial effects of soil and litter invertebrates on plant
growth, in revegetation where Acacia is grown alongside Eucalyptus.
The Forum served to raise the profile of soil biota and disseminate information
about their important roles, but also to encourage interactions among the people
carrying out research on the organisms and interested in applying knowledge to
on-ground practice. Two discussion sessions on the Wednesday of the Forum dealt
with the conservation of cryptogams and the prospects for 'adding soil biota to
the rehab recipe'. The main points from these discussions are summarised below.
It is quite clear from the presentations to the Forum that the hidden soil biota
cannot be ignored in revegetation and rehabilitation. Some significant
challenges remain, including how to increase the knowledge base on these often
overlooked organisms, and how to apply the knowledge to on-ground practice.
One aspect that became apparent when listening to the various talks during the
Forum on soil biota is that relatively intact bushland, with its hundreds
(perhaps thousands) of species of bacteria, invertebrates, fungi, lichens,
liverworts and mosses is a treasure to be greatly valued. It is easy to overlook
these organisms because they are usually small and cryptic, but they play such
important roles, and provide great resilience to bushland.
It would be very interesting to see an estimate of the cost of fully restoring a
hectare of native bush from a cleared site. It is quite feasible to successfully
replant the dominant trees, but to bring back the full complement of species
(including all the fungi) could well run into hundreds of thousands of dollars
or more and take several lifetimes!
Following the soil biota articles, Russell Mawson describes a recent
translocation of the endangered greenhood orchid Pterostylis cucullata.
It is very useful to document this kind of activity, a point also made by Zoe
Smith in her Forum presentation. Future issues of Australasian Plant
Conservation are planned to encourage more reporting of trials (to learn
from successes, and also failures) and to encourage community groups to document
their efforts in plant conservation, such as through translocation,
rehabilitation and revegetation.
The final article is a sobering report on the uncertainty about the future of
several of the Australian Cooperative Research Centres, including the CRC for
Australian Weed Management. The Weeds CRC has many significant achievements and
initiatives in both the environmental and agricultural sectors and it is to be
hoped that a way can be found, such as through a National Weed Centre, for its
vital work to continue.