Orchid Habitat Loss
Incidental
Damage, Australia
text by Alan StephensonAll pictures by Alan Stephenson
I have known of a particular population of Pterostylis baptistii to the south of Nowra for several years. This site also contains numerous other terrestrial and one epiphytic species and none of the orchids within this area are listed under any state or federal legislation as all are what is referred to as “common species”. To further illustrate what I expect is a common occurrence throughout Australia, this area of bush is earmarked for future residential sub-division. The land is situated near St. Georges Basin and Jervis Bay on the south coast of New South Wales and the local area is very rich in orchids generally. It supports Prasophyllum affine, Calochilus pulchellus, Cryptostylis hunteriana, Genoplesium baueri, Speculantha ventricosa and Rhizanthella slateri, all of which are listed species. It was also once home to Arachnorchis cadyi and Arachnorchis tessellata, both of which have disappeared through the ill-considered mechanism of habitat destruction for small hobby farms, a pine plantation and road construction. All of the above species occur or did occur within a five kilometre radius of this P. baptistii site.
Pterostylis baptistii
The area has no signs declaring its status as private property and is used regularly by a range of people who either walk by themselves, in small groups and occasionally with their dogs. A small bush track leads off the main road to the area, running parallel to a small creek and evidence of vehicle use is obvious, although the track provides no formal destination.
A visit in 2009 saw the usual access track deteriorate significantly through vehicle use and a large hole and deep ruts had been gouged at the entrance. This resulted this year in a second track being forged by 4wd’s through the low scrub but as the track goes nowhere in particular I wondered why someone would do this. In early October 2011 I was host to two German orchid enthusiasts, Ursula and Dietrich Rückbrodt and this site was on the agenda for the day because of P. baptistii and they received a bonus of some spectacular Waratahs (Telopea speciosissima), the NSW state flower.
Pterostylis baptistii colony before the damage
Unfortunately the damage by the vehicle was not restricted the beginning of the access track but further along the track at the most dense part of the population of P. baptistii. It is obvious a vehicle had driven in the scrub on the uphill side of the track and reversed down the slope to within three metres of the creek in very wet sandy soil and in doing so had become bogged. Deep channels had been gouged and countless orchids destroyed via incidental damage during the removal of the vehicle from the area. A gap of 3 mts x 10 mts is now obvious and will take several years to naturally regrow, albeit without many of the orchids it once housed. An area of this size is would be considered small area in this or any other section of bush but the damage occurred in the worst (for P. baptistii) possible place in the 450, 000 sq metres of habitat.
Apart from P. baptistii the other orchids known to occur here are numerous plants of Cymbidium suave (in flower during this visit), Microtis parviflora, M. unifolia, Thelymitra ixioides, Thel. media, Thel. carnea, Acianthus fornicatus, Corybas aconitiflorus, Petalochilus carneus, Diuris sulphurea, Cryptostylis erecta and Cryptostylis subulata. There may be others also but time does not always permit a detailed study of each area to search for specific orchids. In addition to those listed, a Xanthic form of C. subulata was located during the course of a paid survey of another section of private property adjoining this site.
During my survey of the site containing the Xanthic form of C. subulata I did not locate any plants of C. hunteriana but as this was undertaken in 2009 at the end of a long dry period I was not surprised, however as the site contains C. erecta and C. subulata and all Cryptostylis species share the same pollinating vector, one must assume the possibility C. hunteriana being in situ.
By now you will have realised this area is not much different from countless other sites throughout Australia and normal (non orchid) people would classify it as “just another patch of bush” as they drive past and this would be a correct assumption. Unfortunately the devil in the detail is the mania my local Council has, in its efforts to sub-divide every such area to increase the residential prospects of the Shoalhaven Shire and therefore the number of properties capable of paying rates. One can only assume a proper survey will be conducted prior to the formal announcement of the development, (whenever that might be) but if present indications are any guide, the area will not require a survey as most of the bush will have been removed illegally by incidental damage by the time this occurs and I feel sure the land owners and Council will not be overly concerned.
Experience tells me that signs indicating private property and/or restricted access will be of little use. Any fence constructed around the area will be costly and will only serve to further isolate native animals already in situ. At current block sizes, approximately 800 homes could be constructed within this area and this incidental damage will pale into insignificance when that occurs, for not only will orchids disappear but by then there will be no Kangaroos, Possums, Antichinus or similar small animals. There are also many large hollow trees spread across the area and most of these have the capacity to provide a home for bird life and in particular large birds such as Ninox strenua (Powerful Owl) and the local icon, Calyptorhynchus lathami (Red Tail Black Cockatoo). One feature not yet mentioned is presence along the track of yet another dumped and burned out car (Holden Crewman) which certainly adds to the aesthetic values of the area and a bold reminder that incidental damage can be cumulative and longer lasting than most of us care to consider.
Plectorrhiza tridentata
A second and equally destructive incident was noted some time ago
(16-4-2010) and only concerned three orchids. Two were good specimens
of Sarcochilus falcatus,
the third was considered the largest plant of Plectorrhiza tridentata
I have seen and this plant measured 500 mm in length. All three shared
a small Myrtaceae
species, which was less than three metres in height. This small tree
was alongside a dirt track leading up an initially steep incline and
was not in any way an obstacle to vehicles and as such should not have
been cut down for this purpose. The track leads off the main road which
runs from Nowra to Moss Vale and at this point is almost 600 mts above
sea level with the level of the
track where
the tree was
growing being
about three metres above the main road. The immediate area is rain
forest although the vegetation varies from wet heath to wet forest
along the 10 km of permissible public access. I have driven along the
track countless times over the past 20 years and have known of the
existence of this Tangle Root Orchid almost since that first day. Also
along this track I have located Cryptostylis
hunteriana and Diplodium
pulchellum, just to list two special species and both were
located only in 1999. It is alsoBranch rescued with Sarcochilus falcatus
home to the only known Shoalhaven site of Corunastylis simulans.
I could almost understand (but not condone) if the plant had been collected but it was almost unrecognisable in the tangle of very small sections of the tree which now littered the ground. I am at a loss to understand how such a plant was not seen by whoever undertook this thoughtless act, as it was a very obvious addition to the tree and particularly as the two plants of Sarcochilus falcatus were within centremetres of this 500 mm Plectorrhiza tridentata.
Sarcochilus falcatus
However the damage is done and cannot be undone but the result is that a giant of its type is lost forever and all through incidental damage.
Alan W Stephenson
Conservation Director
Australian Orchid Council
affine@tpg.com.au