Document ID: chunk:federal_register_of_legislation:F2023L01376:reg:2:p6
Version: federal_register_of_legislation:F2023L01376
Segment Type: reg
Provision Reference: reg 2 (pt 6/8)
Character Range: 32056–35027

of genetic diversity. Neal et al. (2010) investigated the impact of habitat fragmentation on reproduction and growth of new trees in wild M. integrifolia populations, finding that fragmentation is not necessarily detrimental to reproduction in the short term, possibly because of increased flowering when the canopy cover is not as thick. This capacity for persistence is countered by localised seed dispersal and high predation on seeds, which make the species susceptible to fragmentation and variable population growth rates.

Distribution
Macadamia integrifolia is naturally distributed along the foothills and coastal ranges of south east Queensland from the NSW border to Mt Bauple near Maryborough, a distance of approximately 300 km, and is more widespread and frequent in the northern half of its range. The observed pattern of distribution of the species is one of clusters of populations, which are thought to be due to association with refugial habitats arising from long term climate cycles together with limited capacity for dispersal during periods of favourable climate (Powell et al. 2014). The largest number of recorded populations and individuals are located in an area centred on the Amamoor Valley southwest of Gympie; this area may contain up to 90% of the total extant number of this species, potentially more than 10,000 individuals (Neal et al. 2010) of which more than half are mature individuals. The balance of population clusters collectively contains in the order of 500–1,000 individuals. The species co-occurs with M. ternifolia on the Blackall Range and Samford Valley and with M. tetraphylla in the southern part of its range.
Over the extent of its natural distribution, M. integrifolia is generally found within lowland warm complex notophyll vine forest and Araucarian notophyll vine forest, which occur on metamorphosed sediments and interbedded volcanics or alluvia in higher rainfall areas. This species occupies all topographic positions including ridges, scree slopes, foot slopes, gullies, benches and riverine terraces. Soils are predominantly alluvial or volcanic, well drained, often with significant surface exposure of rock fragments. Slope and aspect vary. Elevation range is 5–600 m.
The currently recorded extent of occupied habitat is approximately 1,500 ha and the modelled extent of available habitat is approximately 30,000 ha within an area of 6,800 km2. Total population size is estimated to be between 5,000–10,000 mature individuals within approximately 60 key populations with 10–300 mature specimens at each locality. Further surveys will improve knowledge of population size and distribution. Within the few relatively few areas of intact habitat, it is typically scantily distributed within the vegetation matrix. In disturbed riparian zones, it tends to occur in a clumped pattern of distribution in small remnant patches of habitat that are prone to weed invasion.

Habitat critical to the survival of the