“………threats to its survival from inappropriate fire regimes, weed invasion and ….urban development. …….. Population growth on the northern outskirts of the Sydney metropolitan area is likely to place Z. involucrata in these areas under increasing pressure from such development………involucrata through habitat loss and fragmentation, such development and associated increases in human activity can directly and indirectly affect the species by otherwise contributing to habitat degradation and modifying the environmental conditions experienced at those sites. Such impacts can result from factors including: increased pedestrian and vehicular access to sites, resulting in greater likelihood of trampling, rubbish and garden waste dumping, weed infestations, bush rock removal and transmission of the root-rot fungus (Phytophthora cinnamomi); more frequent fire because of bushfire hazard reduction works and arson; altered overland flows (and associated problems with sedimentation and erosion); and changed soil pH and nutrient levels. ………However, weeds may become an increasingly important threat to populations in catchments where rural-residential and agricultural development along ridgetops is a vector for weed species and promotes their spread through increased nutrient levels in run-off……….Development in close proximity to Z. involucrata sites is likely to cause modification of habitat through altered hydrological conditions, soil pH and nutrient levels, weed invasion, potential introduction of plant pathogens and altered fire frequency. Subsequent increases in pedestrian and/or vehicular traffic through sites may result in trampling, soil compaction, soil erosion and rubbish dumping. Other proposals that result in grazing, slashing, spraying or burning of Z. involucrata habitat are also likely to result in the modification of that habitat………..threatening processes relevant to this species include slashing and herbicide spraying to maintain road verges, grazing and trampling by livestock, weed invasion, rubbish dumping (including green waste, household rubbish and construction materials) and the other disturbances associated with adjacent urban development………..”
Appendix C. Issues related to threats.
The following table shows the species of conservation concern occurring in population growth areas.