Journal Number 110
November 2008

AUSTRALIAN NOTES
By David McConachie

Translocation of Pterostylis cucullata
By Russell Mawson
Reprinted from ANOS (Vic) Bull Vol.41 (3): 13-14, Sept 2008

Pterostylis cucullata is a spring-summer flowering terrestrial orchid. In September / October
2004, I was told of a population of P. cucullata on private land on the Mornington Peninsula in
Victoria.

The owners had applied for a permit to clear trees, to allow for building their house. The shire
representative inspected the site, and P. cucullata was found within the building area.

As this is a national and state listed plant under the Commonwealth Environment Protection and
Biodiversity Conservation Act 1999 and the state Flora and Fauna Guarantee Act 1988, a permit
for translocation from the Commonwealth Department of Environment and Heritage Canberra
was required.

I marked the area of approximately three square metres occupied by the main population, and
estimated there were between 200 and 500 flowering plants.

Almost six months elapsed before the permit arrived and there was a convenient time for the
translocation to start. Since the plants were no longer visible, it was fortunate the markers were
still there. The site was towards the front of the block and quite degraded. The soil was alkaline
sand (pH 8.5 - 9) and easy to work.

Removing and storing the plants

We chose the last week in February to dig the plants out.

The first day saw four of us working and transferring the blocks of soil into styrene boxes which
had a piece of shade cloth placed across the bottom. We used garden spades to cut squares of
soil the width of the blade and about 2/3 the blade depth.

As the day wore on, and with the number of boxes increasing rapidly, we used our hands to sort
the tubers and, as the sand was loose and dry, they were easy to see. The boxes had 75-100mm
of soil put into them, and the tubers were put onto this and covered with a further 50-75mm of
soil.

At the end of the day we had 34 boxes. On the second day, with three of us hand sorting, it took
a bit longer and produced another 24 boxes. The boxes were taken to my home and cared for
until a site within Cape Schanck National Park was selected and approved.

As room to store 58 boxes was limited, I decided to hand sort, count and replant the tubers.
This reduced the number of boxes to 34 containing 1875 tubers between 4mm and 20mm
in diameter. Tubers under 4mm were not counted.

The boxes were placed on benches in a sheltered area and covered with bird wire and 50% shade
cloth. This allowed natural watering of the plants, with approximately three hand watering's
required in the twelve-month time span.

I had placed 48 of the larger tubers in one box and those plants were the first to emerge and
flower in early June, the rest appearing according to size right through to late November.
There were a large number of flowers and ten or twelve seed capsules produced by natural
pollination.

Replanting

A site in the Cape Schanck National Park was chosen, taking into account vegetation, aspect
and soil. The tubers were to be planted in one metre squares.

Over the two days prior to the planting, all the tubers were removed from the soil in the styrene
boxes and washed to remove any remaining soil. This was done to help minimise the risk of
introducing pathogens into the site.

We used a one metre square piece of garden mesh marked into 10cm squares. To hold the
mesh in place, a peg was driven into the ground at each corner of the square and a numbered
disc was attached to a corner peg. In each of the 10cm squares a tuber was planted.

To limit the amount of soil disturbance, a tube was pushed into the ground to a depth of
approximately 70mm and then lifted out, leaving a hole for the tubers. The plug was then
pushed back into the hole.

All the tools used were washed in Phytoclean before they were taken onto the site.

A few tubers had begun to shoot. If this new season's growth was likely to be damaged, the
tuber was placed so the new growth was positioned at the side of the hole and the plug of
soil was crumbled by hand so it fell around the tuber.

We began planting on the 21st of February 2006 and 400 tubers were planted on that day.
By the end of the third day 1400 tubers had been planted at the selected site. More tubers
were planted approximately ten metres on the other side of the track from the first site.

The plants were watered in, and we also had rain within seven to fourteen days after the
replanting. The site has been looked at since and there is no sign of any major disturbance.

Monitoring

As a comparison, this site will be monitored at least once a month over the growing season,
together with the other known sites in the area for a minimum of two years. Further monitoring
will be planned following analysis of the first two year's results.

Monitoring results 2006: of the 1400 tubers in the translocation site 1280 emerged, 306
produced flowers, and 18 seed capsules were produced.

As knowledge of this orchid is limited, some tubers have been retained and potted up to learn
about multiplication, flowering rate and seed viability, as well as providing a seed orchard
should it be required. It is hoped this project will be successful. Time will tell.

It is understood that translocating and re-establishing an orchid colony is a very high risk
strategy and should only be undertaken if the orchids would have otherwise been killed.
The Commonwealth Department of Environment and Heritage granted the permit for the
translocation. The Natural Heritage Trust covered the cost of this translocation. The
Department of Sustainability and Environment and Parks Victoria granted permits.

The people involved with this project were: -Victoria Purdue (University of Melbourne),
Merril Halley and Kirsty Greengrass from DSE, Victor Teoh, Kris Rowe and Sue Mahoney
of Parks Victoria, Gidja Walker, Imelda Douglas and Russell Mawson (also representing
the Australasian Native Orchid Society, Victorian Group).