Some of the major degrading effects are as follows:
1.Hydrology: Invariably the hydrology of an area is altered by urban development. More obviously this occurs to ensure adequate drainage of the area and to minimize local flooding. This has a degrading effect on some remnant vegetation. For example, stands of Red Gums at Lyndhurst, southeast of Melbourne, are dying as a result of the changes to hydrology that were necessary to ensure proper drainage for residential development in the area (XXXX XXXX– pers. comm.). Changes to hydrology can occur for other reasons other than adequate drainage, for example to provide a detention basin or to move a drainage line to what is considered to be a more appropriate location or to replace it with underground pipes. Changes to hydrology can degrade vegetation, which is especially important if the threatened communities are already in a degraded state as is frequently the case. None of the existing action statements seem to adequately address this issue. Ultimately, the solution could well be to keep urban development well away from threatened vegetation communities.
Increased run off from urban development can result from covering areas with impervious surfaces and this may have a degrading effect on both waterways and vegetation through which the increased flows pass. Furthermore, urban development usually increases the amount of pollution in storm water, which may also have a degrading effect especially on sensitive native vegetation. Again, this may not be particularly significant if the vegetation is not threatened as noted above. In addition, this does not appear to be adequately dealt with in action statements.
2.Traffic: Additional traffic (foot, cycle and even motor vehicle) associated with urban development, in and around remnants of threatened vegetation, can degrade vegetation by causing soil compaction and providing greater means for spreading disease (e.g. Phytophthora cinnamomi). Increased spread of diseases from these mechanisms is more likely to occur adjacent to urban development. This may not be significant if the vegetation is not threatened since it will most likely be more prolific and protected in other areas so that its degradation adjacent to urban development may not pose a serious threat. Where vegetation is highly threatened (perhaps critically endangered) all remnants, even the most degraded, may require special protection from disease (and other threats of increased traffic) if extinction is to be prevented. Threatened vegetation communities are usually grossly under represented in reserves or not at all.
3.Restricted management: Restriction on the techniques available for proper management of threatened vegetation adjacent to urban development results in further degradation. This is of great concern if a threatened vegetation community is involved. For example, many threatened vegetation communities require ecological burning as part of their management strategy but, due to other conflicting objectives, this is usually not possible abutting residential development. For example see Victorian FFG Action Statement No 53 Western (Basalt) Plains Grassland Community, which notes this shortcoming but does not mandate a remedy.
4. Introduced species: Proliferation of introduced species tends to occur more especially adjacent to urban development further degrading remnants of native vegetation. The disturbance zone created by adjacent developments is often more readily colonized by exotic species, due to a number of fringe effects (see for example 2.3.2 (i) para.2 in "Urban Bushland Under Threat: Review of Urban Bushland & Recommendations for its Protection", May 1996 The Nature Conservation Council of NSW). Again this may not be so significant if the vegetation is not threatened as noted above.
The presence of domestic animals and poor control of them and the increased risk of them becoming feral is greater where there is urban development. Feral animals threaten native wildlife by direct predation or increased competition. The destruction of wildlife may contribute to the degradation of vegetation community remnants and in threatened communities may place species at risk of extinction.
Introduced species of both flora and fauna normally associated with urban development, e.g. rodents, may compete with (or otherwise place stress on) native species of both flora and fauna thereby potentially contributing to the degradation of threatened communities already on the path to extinction and unable to withstand such pressures, pressures which non-threatened communities may be able to tolerate.
5. Change in assemblage: There are native species that thrive adjacent to urban development while others progressively decline. When this occurs in a native vegetation community it can distort the mix of species. If the species mix is altered significantly, this is an effective form of degradation. Again this may not be particularly significant if the community is abundant and not threatened as noted above. The effect can occur with fauna as well as flora, especially fauna that may be critical to the health of a threatened ecosystem remnant.
Some insectivores (e.g. pardalote) tend to decline adjacent to urban development. This can have the effect of reducing the natural protection of native vegetation against debilitating pests. It is particularly significant if the vegetation is already stressed, as is usually the case with threatened vegetation communities.
6. Construction activities: The process of construction for both buildings and infrastructure (e.g. roads) can frequently degrade native vegetation and is especially significant if the vegetation is threatened. EPA rules help to minimize the damage caused by dust, trampling by foot and machinery, run-off from the construction site, waste etc but are frequently ignored. Degradation may occur inadvertently because the presence of the threatened vegetation has not been identified. This may be because the remnants are degraded or because it is a time of the year when their presence is not readily identifiable. The threat to listed species and communities could be eliminated if construction was kept well away from them. None of the existing action statements seem to adequately address this issue.
7. Pollution: Increased carbon dioxide level has been identified as a potential cause of dieback in both trees and other native vegetation. Increased levels of carbon dioxide tend to occur where there is urban development (from both motor vehicles and home heating). This degradation may not be of great consequence in vegetation communities that are not threatened but it can accelerate the decline of threatened vegetation communities that are invariably already degraded and in decline. Pollution from household and industrial waste tends to become more significant the closer the proximity to urban development. Such pollution affects vegetation communities as well as waterways. The degradation to non-threatened communities may not be of undue concern but its impact may be significant if it causes degradation to a threatened community. There are potentially two solutions: eliminate the waste or prevent development from occurring close to threatened vegetation communities (as distinct from non-threatened communities). Attempts to achieve the former have had limited success. If the latter approach were adopted it would most likely solve this problem.
Appendix A lists a number of extracts in support of the above as well as other degrading affects. Appendix D lists threats from urban and industrial development to our water environments and the species and communities therein and may apply to a greater or lesser extent depending on the circumstances. Many of the issues raised have implications for terrestrial ecosystems. Such threats have special significance for threatened communities. Maintaining adequate distance between development and waterways and drainage lines feeding them is crucial to prevent the degradation of threatened communities in water environments and adjacent riparian areas. When such distances are great enough intervening vegetation may also act as a filter.
While many non-threatened and abundant vegetation communities may be able to withstand some loss and degradation without being threatened with extinction, many of our threatened ecosystems are on the brink of extinction and others are not too far away. Most of our non-threatened vegetation communities are not only abundant but also protected in green wedges and reserves. Not so our threatened communities.
Conservation and reservation has tended to favour less depleted EVC's possibly because there are more good quality remnants of reasonable size. For example, Table A, Appendix A shows the reservation of broad vegetation types in the greater Melbourne area (Port Phillip & Westernport catchment) and shows the disproportionately neglected reservation of threatened vegetation types. A further example is FFG listed (Victorian Government Gazette, 20 September 2005) Western Basalt Plains (River Red Gum) Grassy Woodlands the reservation of which is zero.
The priority need therefore, is to provide protection to the threatened, rather than all native vegetation communities so as to direct the threat away from the weakest. Protection of all native vegetation communities against the urban threat could dilute the effect of that protection, protection which should be concentrated where it is most desperately needed.
Section 2 - Impacts on Native Species and Ecological Communities
General information on the mechanism of impact should not be included in this section - this is part of the description.
In this section only one pair of questions 4/5, 6/7 or 8/9 need to be answered. However, providing all available evidence against each question will aid in assessment on the nomination.
The criteria for listing a species (Part B) or ecological community (Part D) under the EPBC Act are and the Threatened Species Scientific Committee guidelines at the end of this form. It is important to refer to these criteria when answering questions in this section.
The EPBC Act lists of threatened species and ecological communities are available on the Department of Sustainability, Environment, Water, Population and Communities website at: www.environment.gov.au/biodiversity/threatened/index.html
For each ecological community: the complete title (published or otherwise generally accepted), category it could become eligible for listing in.
5. Provide justification that the species or ecological communities detailed at question 3 could become eligible for listing in any category, other than conservation dependent. For each species/ecological community please include:
data on the current status in relation to the criteria for listing;
specific information on how the threatening process threatens this species/community;
information on the extent to which the threat could change the status of the species/community in relation to the criteria for listing.
EPBC Act Listed Species/Ecological Communities
6.Provide a summary of those listed threatened species or ecological communities that, due to the impacts of the threatening process, could become eligible for listing in another category representing a higher degree of endangerment. Please include:
a. For each species: the scientific name, common name (if appropriate), category it could become eligible for listing in;
For each ecological community: the complete title (published or otherwise generally accepted), category it could become eligible for listing in.
7.Provide justification that the species or ecological communities detailed at question 6 could become eligible for listing in another category representing a higher degree of endangerment due to the impacts of the threatening process. Please include:
data on the current status in relation to the criteria for listing (at least one criterion for the current listed category has been previously met);
specific information on how the threatening process significantly threatens this species/community;
information on the extent to which the threat could change the status of the species/community in relation to the criteria for listing. This does not have to be the same criterion under which the species/community was previously listed.
8. Provide a summary of those species or ecological communities, listed as threatened under the EPBC Act, that are considered to be adversely affected by the threatening process. Please include:
For species: the scientific name, common name (if appropriate) and category of listing under the EPBC Act;
For ecological communities: the complete title (exactly as listed) and category of listing under the EPBC Act.
The following list is not exhaustive but includes threatened species and communities where development is identified as a threat in national recovery plans for those items. Extracts from relevant recovery plans are included in Appendix B.
9. Provide justification that the species or ecological communities detailed at question 8 areaffected adversely by the threatening process.
The species and ecological communities detailed at question 8 are affected adversely by the threatening process (nominated here) as outlined in their EPBC act national recovery plans, extracts of which are provided as Appendix B.
Over 40% of nationally listed threatened ecological communities and more than 50% of threatened species occur in the urban fringe (Newman et al. (2001) P13. See appendix A). Their continuing decline and the threats from all aspects of development and occupation by humans is well documented (see appendices). Concentrations of threatened species frequently occur near development or areas proposed for development (Victorian Flora and Fauna Guarantee act Action Statements - see Appendix C). The largest present and future threat to endangered plants species is low numbers (Australia's Environment: Issues and facts (Cat. No. 4140.0 p 25 - see Appendix C). Reinstatement of threatened habitat is generally considered to be at least part of the solution. Development of land suitable for reinstatement prevents that reinstatement.
Although residential and industrial development is not at the head of the list it is implicated in other major items (e.g. roadworks, weed competition). While the present and future threat from agriculture is less than half the past threat, that from industrial and urban development remains the same. There is no overwhelming reason why development needs to occur in areas where species and communities are at risk. There are invariably suitable alternatives. Restriction of development to a healthy distance from these areas could substantially reduce the risk or at least stop it from becoming worse and thus make at least a similar contribution to that made by agriculture. It may also allow reinstatement of habitat. Further, it may improve the quality of development. By encouraging development away from farmland it is more likely to encourage it into stable but infertile upper slopes of hilly areas with a view and less prone to flooding and tsunami.
Loss of biodiversity is further contributed to because development tends to occur where there is the least information about biodiversity (A Reference Guide to the Ecology and Natural Resources of the Melbourne Region" Mark J. McDonnell et al 1999 ARCUE - see Appendix C).
Existing clearing controls protect better quality remnants of threatened ecosystems but do not prevent them from being surrounded by development nor do they guarantee areas for recruitment necessary to ensure their long-term survival. Where connecting corridors are provided the resulting assemblages usually have an unnatural configuration and extraordinarily high perimeter to area ratio and are still surrounded by development. Clearing controls also do not guarantee a distance between remnants of listed communities and the threats posed by all aspects of development and which are generally common knowledge; a distance sufficient to provide reasonable protection and promote long-term viability.
Areas that have been cleared but not built on are potentially available for reinstatement but once they have been built on the loss is effectively permanent. Something in addition to clearing controls is necessary if those clearing controls are to be effective in ensuring the continued high quality of remnants and their ultimate survival. This nomination is intended to deal with the threats of development other than the clearing of good quality remnants and to complement the latter and to thus assist in halting the continuing decline of listed species and communities.
There are many rules and regulations designed to ensure the protection of threatened species and communities but their effectiveness is often compromised because they are difficult to police. Probably the major cause of biodiversity loss is, indirectly, the rezoning of areas for development that seriously affects listed items. A current example is the proposal by the Victorian government to extend the Melbourne urban growth boundary into listed grassland areas. We suggest listing the development, nominated here as a key threatening process, would discourage this practice, which we believe to be a contravention of the Convention on Biological Diversity.