Monday 12 August 2013

Endangered Geranium from Riddells Creek Protected by Law

It was thought to be extinct for about 100 years until it was rediscovered in Riddells Creek a decade ago. The Large-flower Crane's-bill or Large-flower Geranium (Geranium sp. 1) was listed on the State's Flora and Fauna Guarantee Act (FFG) in May 2013. This means the species is now protected by law.


Anthers cream to (pale-)yellow.
Pics by Russell Best from plants at Riddells Creek.Pale-yellow anthers mostly on paler flowers (TBC).

Cream anthers mostly on pinker flowers (TBC).



It was first rediscovered on the Rail Reserve near Hamilton Road. This location, a small, precarious 10m wide stretch of remnant grassland vegetation is by far the largest known population of this plant species on the Planet. Riddells Creek Landcare have worked with DSE and Vline for a number of years to try and protect the population from illegal bikers and 4WDs that were breaking down DSE's protective fences to access this Vline land.

Its main distinguishing feature is its large flower, which can be twice as large as any other native Geranium. The flower size ranges from 15-25mm in diameter, whereas the plant itself can spread to 1.5m wide.



Since the plant's rediscovery, about four other tiny populations were found from Glenroy to Castlemaine but it is feared that only one of these other populations may have survived the drought last decade (two populations have not been properly confirmed). Locally, Riddells Creek Landcare have searched in most suitable areas where the plant might grow and have found two new but very small populations at different places along the rail line as far as Clarkefield.

In Riddell, the areas where the plant occurs is always poor soils on areas with underlying basalt (volcanic) rock. The areas are prone to temporary inundation after heavy rains and this seems to be a requirement for its growing cycle. Like most native Geranium species, plants die back considerably after flowering leaving only a few 'winter leaves' (in Autumn-Winter). In the worst of the worst of the drought, 2008-9, all the plants completely disappeared. As a precaution, Riddells Creek Landcare quickly applied for a special DSE permit to collect seed before the last plants disappeared - we managed to find just 12 seeds! Thankfully, we can now confirm that in extreme drought conditions, plants die back completely to a large underground tuber and leaves re-emerge after good rain. The seeds we collected were grown on and have since been planted in Wybejong Park by Greening of Riddell. Because of the very specific requirements of the plant, plants grown in pots are proving hard to keep alive. Indeed, many plants were transplanted by DSE during the 2005 rail upgrade but none of the transplanted plants seem to have survived either. Given the specific and extreme condition this species endures, the added pressures of climate change would seem to make this species particularly vulnerable to extinction. What we are also finding is that because the Victorian Volcanic Plains have been decimated over the past two centuries (and is continuing today) there are no suitable, protected places left to act as a sanctuary for this species.

There is a significant discrepancy in the FFG Act (and the national EPBC Act) such that if a species is known to be extinct and isn't listed on the Act (this sometimes happens for species like Geranium sp. 1 that have been 'extinct' for a long time prior to the Act coming into existence), then if it is refound it isn't automatically protected by law until it is put through the formal processes of the Act! Madness!!

There are now nine species in Riddells Creek that are deemed to be in danger of extinction from the wild in Victoria and protected on the FFG Act. The other eight species are:
  1. Dianella amoena (Matted Flax-lily) - populations monitored by RCL members and plantings undertaken at suitable sites
  2. Stylidium armeria subsp. pilosifolium (Hairy-leaf Triggerplant) - discovered by RCL members
  3. Purple Donkey-orchid - population monitored for DSE by RCL members
  4. Amethyst Hairstreak Butterfly - population discovered by RCL members
  5. Yellow Ochre Butterfly - population discovered by RCL members
  6. Growling Grass-frog - frog heard by Melbourne Water employee a couple of years ago
  7. Brush-tailed Phascogale - RCL to soon make efforts to re-find this species in Riddell
  8. Powerful Owl - populations well known to RCL members up the Sandy Creek valley

Here is a link to the above species on NatureShare:
http://natureshare.org.au/species/search/1768/

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