Field collecting on Kangaroo Island

Date posted: 07 March 2018

This article first appeared in Issue 32 (July-December 2017) ofSamara, the International Newsletter of the Millenium Seed Bank Partnership (MSBP)

By Dan Duval and Dr Jenny Guerin

Kangaroo Island lies 14 km off the south coast of Fleurieu Peninsula in South Australia and became separated from the mainland approximately 9,500 years ago (Robinson & Armstrong 1999).

The island is nearly 150 km long and 4,400 km2 in size and contains over a thousand native plant species, more than 50 of which are endemic.

The western third of the island is protected within the reserve system and provides refuge for many species of fauna and flora that are threatened or extinct on mainland Australia.

There are 17 plant species on the island listed as nationally threatened under the Commonwealth Government’s Environment and Biodiversity Conservation (EPBC) Act of 1999.

The majority of these species occur on the island’s eastern end, which was historically cleared for agriculture.

Most of the remaining native vegetation is now restricted to roadside verges.

A number of threatened and endemic plant species co-occur in Kangaroo Island Narrow-leaved Mallee (Eucalyptus cnerifolia) Woodland that is itself a critically endangered ecological community listed under the EPBC Act.

We aim to make representative seed collections from remaining roadside populations and to develop effective germination protocols for these species.

One of the threatened plants from this community is the saddleleaf phebalium (Leionema equestre), a plant species which has been observed to be fire responsive; we have banked seeds from four populations of this endangered phebalium.

Fire may also have a role in the recruitment of some other species, for example, seeds of the Kangaroo Island spider-flower (Grevillea muricata), a vulnerable endemic plant, were found to germinate after treatment with dry heat and smoke water.

There have been many discoveries during our work on the island, including the endangered Kangaroo Island pennywort (Hydrocotyle diantha) not recorded there since 1886.

We stumbled on this tiny herb whilst crawling under Melaleuca shrubs in wet swamp searching for other rare plants in Kelly Hill Cave Conservation Park.

We also discovered the tiny Goodenia micrantha, not previously recorded in South Australia, growing in wet flats in the same area.

This species is better known for growing in heath in southwest Western Australia nearly 2000 km away.

The South Australia Seed Conservation Centre has made over 200 seed collections from the island, predominantly of threatened and endemic species, since the inception of the program and partnership agreement with MSBP in 2003.

Approximately 80% of the endemic taxa and nearly 40% (58 taxa) of the island’s threatened flora have been banked, including multiple provenance collections for 23 threatened taxa.

Further research is required to investigate dormancy mechanisms for some species to improve seed germination rates.

During the partnership, a data portal has been created to enable the SA Seed Conservation Centre to share its data and scientific knowledge.

This information supports the Natural Resource Management Groups managing land and conservation work across South Australia and is a key resource for researchers.

Find more information about the Kangaroo Island flora and what has been banked as part of the MSBP at www.saseedbank.com.au.

Learn how you can help save some of SA's extraordinary native plant species from extinction.

References

Robinson, A.C & Armstrong, D.M (eds)

(1999) A Biological Survey of Kangaroo, Island, South Australia, 1989

&1990. (Dept. for Environment, Water and Natural Resources)

http://www.environment.gov.au/biodiversity/threatened/publications/kangaroo-island-mallee-eucalyptus-cneorifolia-woodland-ecologicalcommunity-factsheet ecological community