It has been objective of the MCCG to restore the flora in the Moggill Creek Catchment to pre-settlement conditions.
In accordance with this, the MCCG has a policy of planting seedlings raised from seed collected in the catchment area. These seedlings are considered to be the local forms of species that are best adapted to the area and are species which would have been prevalent around pre-settlement.
Bryan Hacker has advised that the Nursery does sometimes use seed from outside the catchment when collecting local seed is impracticable. Often, species that were previously in the catchment are now in very small numbers or have been lost.
One of the side effects of climate change is that the zones expected to be suitable for various local species are expected to move South as the temperature warms. For birds and animals this should not be difficult as they can walk or fly South, but with plants it is a different matter.
Climate change has happened in the past and plants have been able to adapt. Although some species were probably lost, most were able to gradually move to more suitable climes. But this time it is expected that the climate will change much more quickly and the Intergovernmental Panel on Climate Change (IPCC) estimated that only 75% of species could make the move. This means a huge number of extinctions.
There is a varying amount of genetic diversity among individual species. Diversity is beneficial: greater diversity means increased ability to adapt to changing conditions.
Perhaps our policy of only propagating local forms when available should be reconsidered in light of present theories about climate change.
Should we consider bringing in seed from plants of species that we have locally from more Northern areas in order to gain diversity? Could this help our local plants adapt as the climate gets warmer?
A case in point is the Grey Gum (Eucalyptus punctata). The Brisbane region is located near the Northern boundary of where the Grey Gum grows. There are odd locations of this species up to about Bundaberg and inland to Monto, and an isolated population occurs in the Barakula Forest. This magnificent tree is very selective in where it grows and seed from more Northerly areas may be a trigger to bring in the additional genetic diversity that will allow us to keep this important Koala tree thriving in the catchment as the climate warms.
Trunk of a Grey Gum, (Eucalyptus punctata) at
Brookfield, showing scratches from koalas.
This is one of the koalas’ favourite food trees in
A dilemna for us all to ponder:
If we are messing with climate shouldn’t we give nature a helping hand to make up for the damage we are doing?
Or would we just once again be interfering with nature and should we simply accept the extinctions we may be causing?