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Western myall/chenopod open scrub
This vegetation association is poorly conserved in the park system in this state. There is concern for the long term survival of Western myall and some other arid and semi-arid zone trees and shrubs. Many of these rely for recruitment on episodic rainfall events, which occur approximately five times a century, This may lead to large gaps in the age structure of plant populations and a possibility of extinction in areas where recruitment is suppressed.
Recruitment may fail or the rate be lowered in a number of ways, for example, seed-eating ants harvest, store and eat large numbers of seeds making them unavailable for germination (Ireland, 1992). A large proportion of seedlings may be eaten by the high population of rabbits in the area (Lange, pers. comm., 1991). Fire is also a significant threat as this group of plants is killed by fire. A survey carried out in 1993 (Lewis, 1993) revealed that some individuals of the 1974 recruitment of Western myall have survived in the Whyalla Conservation Park, but none have survived outside the southern boundary fence of the Park or at adjacent Tregalana station. These factors mean that conservation of these associations is especially important in reserves where harmful effects can be effectively minimised.
Colonisation by Punty bush or Desert cassia (Cassia nemophila now Senna artemisioides)
Punty bush or Desert cassia was virtually absent in the Park prior to 1974 but abundant in the land to the south. It appears to be spreading into the Whyalla Conservation Park from the land beyond the southern boundary fence and may become a woody weed if it continues to colonise at its present rate (Lewis, 1993). A re-survey of distribution and age structure in future years will reveal whether new recruitment has occurred as a result of the 1992 and 1993 rains (Lewis, 1993).
Monitoring
Photo-points were established throughout the Whyalla Conservation Park in 1974 by Lewis to monitor vegetation changes. The photographic records belong to the University of Adelaide, Botany Department.
Inventory
Plant species lists have been compiled (and need more work before they are complete). There are well over 100 plant species in the Whyalla Conservation Park. These include the Common fringe-lily (Thysanotus tuberosus) which appears in Schedule 8, Vulnerable Species of the National Parks and Wildlife Act, 1972-1981.
There is an herbarium collection of north-east Eyre Peninsula region plant species at Middleback Field Centre and another is being established at the University of South Australia, Whyalla Campus. The Friends of the Whyalla Conservation Park Group has begun a photographic herbarium.
Research
Research has been carried out on many aspects of the north-east Eyre Peninsula region plant species by the University of Adelaide, at the Middleback Field Centre, and the University of South Australia, at the Whyalla Campus. The records of both these institutions are a basis for further research in the Park.
Revegetation
The Friends of the Whyalla Conservation Park have carried out revegetation activities, including seed collection, propagation, seedling planting, direct seeding, closing of tracks, eradication of rabbits, excluding the public from certain areas and weed eradication over the past few years. The plant species used for seedling planting has been primarily Western myall.
Lichens
The Park lies within the Australian Heritage Commission "area of significance" for ground lichens and mosses. This area is bounded by the Lincoln Highway on the east, the Whyalla to Iron Knob road on the south and a north-east diagonal road from Iron Knob to the Lincoln Highway.
The ground lichen and moss crust is delicate and easily damaged. The crust has an important role in stabilisation of the soil. Cyanobacteria which are also present in the crust are able to fix atmospheric nitrogen, making it available to other living organisms.
The mammal fauna of the eastern Eyre Peninsula has been decimated since European settlement and many of the smaller mammals are now locally extinct. The fauna of Whyalla Conservation Park has not been surveyed, but interesting sightings have been made, and the Park provides important habitat/refuge for local native species, particularly reptiles.
Whyalla Conservation Park is relatively small (1 100 ha). It is surrounded by a large area of vegetation contiguous with that of the Park. Land use varies from pastoral activity on the north and west of the Park to industrial-zoned land currently vacant or used for recreation elsewhere.
Vulnerable species
There is some evidence that the population of the Peninsula Dragon (Ctenophorus fionni) has declined in the Park and may now be extinct on Wild Dog Hill where it has not been sighted since 1984. There are no known populations of Peninsula Dragons closer than Mount Young, approximately 15 km to the south (Hilton, 1994, Whyalla Herpetology Group. pers. comm.).
The Thick-billed Grasswren appears on Schedule 8, Vulnerable Species, of the National Parks and Wildlife Act, 1972-1981.
Intense rainfall in major episodic events are a part of the region's climate. Erosion resulting from such events is a problem, especially in the eastern end of the Park, around Wild Dog Hill and along the northern boundary road on the eastern slopes of Trig Hill.
The southern boundary road currently acts as a drainage channel for overflow from the dam situated in the Park. This dam remains from the Park's pastoral past. The dam has impacted significantly on the natural drainage within the Park.
Soils in the Park are vulnerable to erosion if the surface coating of lichens is disturbed or other ground cover removed.
Whyalla Conservation Park is utilised for research and monitoring. Schools, the University of Adelaide and the University of South Australia make use of the Park for education and research purposes, including Honours theses and the like. The Park's system of photo-points was established in 1972 by Megan Lewis of the University of Adelaide. It has provided an extended photographic record of vegetation change in the Park and is an example of studies being used for the benefit of the Park (Map 7 shows the location of these).
While student activities raise awareness and have benefits, they can also have adverse impacts, particularly where the Park is used on a regular basis by large groups. The proximity of the Whyalla campus of the University of SA makes this a possibility. Guidelines need to be set up to ensure that student activity in the Park is sustainable.
There is a requirement for groups to notify NPWS of intention to use a reserve, including details of activities, participants and emergency contacts. A "Trip Intentions" form has been developed for this purpose.
Permanent marking has been established for reference grids for research and Park protection work.
