review of Urban COnservation strategy undertaken in durban metropole area and gautengprovince
Submitted by
Biodiversity & Conservation Biology Department,
University of the Western Cape
Marlene Laros & Associates – Sustainability Matters
Settlement Planning Services
And
GISCOE (Pty) Ltd
April 2004
MARLENE Laros & AssociatesSustainability Matters
Sustainable environmental policy, planning
and management solutions
P O Box 22750
Scarborough 7975
south Africa
Ph: 27 21 7801120 / 0833259964
Fax: 27 21 7801327
Email:
Table of Contents
Executive Summary……………………………………………………………………...3
Section 1: Introduction and Background………………………………………..…...... 4
1.1 Durban…………………………………………………………………………4
1.1 Gauteng………………………………………………………………………..4
Section 2: Location and characteristics of Study Area…………...……………………..5
2.1 Location…………………………………………………………..…………………….5
2.1.1 Durban……………………….………………………………………………5
2.1.2 Gauteng…………………………………………………………………….....5
2.2 Climate……………………………………....………………………………………….5
2.2.1 Durban……………………………………………………………………….5
2.2.2 Gauteng…………………………………………….....………………………6
2.3 Biodiversity…………..……………………………………………………………….6
2.3.1 Durban…………………………………………….…………………………6
2.3.2 Gauteng…………………………...………………...... ………………………7
Section 3: Methods Used in Prioritization of Conservation Network….…..………….9
3.1 The Open Space plan in Durban………………………………....……………………..9
3.1.1 The D’MOSS framework plan…………………...………….………………...9
3.1.2 The design of the Open Space plan...... 10
3.1.3 Methods used in the prioritization of the DMA Conservation Network.…...... 10
3.2 Gauteng Biodiversity GAP Analysis Project………………………...... …………11
3.2.1 Summary of study process……………………………………...……………11
3.2.2 Methodology used in Conservation Planning Analysis……...……………..…12
Section 4: Results………….…………………………………………………………….13
4.1 Durban………………………………………………………………………………..13
4.2 Gauteng……………………………………………………………………………….13
Section 5: discussion………….…………………………………………………………14
5.1 Durban………………………………………………………………………………..14
4.2 Gauteng………………………………………………………………………………14
Section 6 Implementation and Management………………………………………….16
6.1 Durban………………………………………………………………………………..16
6.1.1 Implementation of D’MOSS………………..……………………………….16
6.1.2 Management Strategy……………………………...... ………………………16
6.2 Gauteng……………………………………………..…………………….…………..16
6.2.1 Implementation of BGAP……………………………...……………………16
6.2.2 Management Strategy…………………………………....…………………...16
Conclusion………………………………………………………………………………17
References……………………………………………………………………………….18
Executive Summary
Cape Town is one of three cities worldwide, which ranks as an urban biodiversity hotspot. Conservation of this unique urban biodiversity requires long term planning and commitment and requires a model on which to base such a strategy.
The cities of Durban andPort Elizabethas well the province of Gautenghas already incorporated urban conservation initiatives that contribute significantly to the protection of biodiversity. These initiatives also enhance the stature of these citiesand add to their attractiveness as a lifestyle attraction as well as enhancing their tourist potential[1].
How these cities developed and implemented their conservation strategies can be used as a template on which to incorporate the vision of a biodiversity Network within the city of Cape Town. In this review, Durban and the province of Gauteng are discussed in detail with respect to the methodologies used in creating a conservation network.
Section 1: Introduction and Background
1.1 Durban
The Durban Metropolitan Open Space System Plan focused on the design of an open space plan to protect and guide the management of the city’s natural resource base (Roberts and Diederichs 2002). Despite the loss of many biodiversity features, the City still hasa remarkable array of biodiversity to conserve.
The impact of urbanization and a growing population has lead to an increase in the demand for goods and services, which equates to an increased use of the environment for housing and recreational needs.
Durban’s open spaces contain valuable natural resources.The city supports a third of the Province’s population as well as 60 % of its economic activity (Ethekwini Municipality 2003). This coupled with high levels of poverty, unemployment and a large housing backlog, has placed high demands on local ecosystems while at the same time, impacting negatively on biodiversity (Ethekwini Municipality 2003).
Open space planning began in Durban 20 year’s ago and as a result has developed into a 5-phase framework plan, which had its conclusion in 2002. Consequently all Nature Reserves and green areas are linked via a system which is unique to Durban, known as D’MOSS (Durban Metropolitan OpenSpaceSystem).
The Durban Metropolitan Council created green corridors, which meander through Durban, joining vital core areas of conservation significance and allowing fauna, and flora a corridor along which they can travel, ensuring diversity and eliminating genetic isolation.
1.2 Gauteng
Gauteng, the smallest province within South Africa, is located within both the savanna and highly threatened grassland biomes that together constitute six vegetation types (Pfab March 2003).
Gauteng is also the most highly populated province as well as the most urbanized. This has consequences on the biodiversity of the province as industrialization, mining and agriculture all contribute towards a loss in biodiversity. ABiodiversity GAP Analysis Project (BGAP) was undertaken to identify and map areas that are of biodiversity importance in Gauteng, through a systematic and empirical conservation-planning program (Pfab May 2003).
Section 2: Location and characteristics of study area
2.1 Location
2.1.1Durban
Durban is situated on the eastern seaboard of South Africa within the province of Kwazulu Natal and covers and area of approximately 2297 km2. Steep escarpments in the west and coastal plains in the east characterize the Durban municipal area. Added to this, the area has 98 km of coastline with 18 river catchments which greatly increases the biodiversity features of this City.
The Durban Metropolitan Area (DMA)contains a number of habitats, most are seriously threatened by urbanization as the city expands in order to accommodate the increasing population.
Due to its geographic location, theKwazulu-Natal area also brings together three distinct elements:a tropical influence entering from the north, a warm temperate influence from the southwest and a transition area, which is the Durban area itself.
2.1.2 Gauteng
Gauteng is situated in the northern part of South Africa on the central highveld plateau at an average altitude of 1500 meters above sea level and coversapproximately 17 000 km2 which totals about 1.4 % of the total land surface of South Africa.
It is the smallest province in the Country but has the most dense population (8 million) who strain the natural environment. The greater Johannesburg Metropolitan area forms the largest urban complex in South Africa.Gauteng falls within both the savanna and highly threatened grassland biomes.
2.2 Climate
2.2.1Durban
Durban has a humid subtropical climate with a high rainfall (Generally 1000 mm/annum), which occurs predominantly in summer. The area has a warm summer and a mild winter owing to its subtropical climate. Daytime temperatures within the area extend from 18 °C to 24 °C with summer maximum temperatures reaching the lower thirties. Humidity often falls between 50% and 70%. Prevailing winds are mainly parallel towards the coast with south-westerly and north-easterly winds roughly balanced in frequency. This generally makes for high wind variability.
2.2.2 Gauteng
Gauteng has an average annual rainfall of 850 millimeters (Rainfall is to be expected only in summer from October to March) , and a mean daily sunshine factor of 8.7 hours per day, one of the highest in the world. Gauteng lies in the summer rainfall area of South Africa, often resulting in spectacular afternoon thunderstorms sweeping across the highveld.Daily temperatures range between an average midsummer (January) maximum of 26ºC and an average winter (June) maximum of 16ºC.In winter, the nights can be quite cold; even below zero, but during the day the sun shines and lets the temperatures rise up to 25 degrees.
2.3 Biodiversity
2.3.1 Durban
The DMA has been drastically affected by urbanization within the last 150 years as seen by the virtual decimation and disappearance of the subtropical lagoons and mangrove swamps from the bay area and adjacent rivers (e.g. Mgeni and Umlazi). There has been a significant degradation of the DMA’s terrestrial resource base mainly attributed to the expansion of the city. All of the larger mammal species, which occurred within the DMA, are locally extinct. The area however is historically biologically rich as it occurs within a biological transition zone (Figure 1).
Figure 1: Durban transition zone
The DMA is situated within two biogeographic regions commonly referred to as a transition zone (Fig 1). This transition zone brings together two neighbouring regions. The two neighbouring regions bring together not only different species but also certain endemic species, which are specifically, adapted to the transition area/region.
Being situated within a biogeographic transition zone, the DMA is a region of high diversity situated between the CapeTemperate habitat and the tropical Mozambique habitat (Anon 1). Four of the seven S.A biomes occur in the region and 34 Red Data species occur locally. Terrestrial resources include approximately 3000 plant species, over 350 bird species, 67 mammal species, 36 snake species and 21 lizard and skink species.
Table 1: DMA habitats and current status
Habitat type / Land Cover / Current StatusGrassland / Grasslands / Largely transformed in Durban with few areas remaining, Areas still remaining are highly fragmented
Mangrove Swamps / Floodplains and Estuaries / Mostly destroyed with few remnants left
Dune and Coastal forests / Forest / One prevalent along the coast now largely destroyed
Valley Bushveld / Forests / Occurs in dry inland rivers but has been poorly studied hence not a lot of information is available
Wetlands (Fresh water and estuarine) / Water bodies/ Floodplains/ Estuaries / Only small areas remain. Most impacted habitat
Cliff and Scarp vegetation / Riverine Forests / Largely protected due to inaccessibility but as yet also poorly studied
Table adapted from Anon 1 (2002).
The DMA also hosts an impressive marine diversity. The 83 km coastline is home to numerous tropical and subtropical plants and animals, many of which are endemic (Ethekwini Municipality 2003). Thirteen estuaries, most of which support high biodiversity, also punctuate the coastline.
2.3.2 Gauteng
The province has an estimated 3303 plant species, 125 mammal species, 326 bird species, 25 amphibian and 53 reptile species of which 25 plant species are endemic or “near endemic” (Pfab March 2003). All of these endemics however are threatened with extinction and 56% of them are critically endangered.
The province is characterized by rolling hills, FoldMountains and flat savannahs with sporadic scrub brush. Most of the original woody plant species have disappeared due to the high concentrations of aluminium in the soil as a result of mining, but foreign species of trees include Acacias, Jacaranda trees with their purple flowers in October and Eucalyptus trees in woody clusters. There are a few rivers and the VaalRiver to the south and the impressive MagaliesbergMountains to the north form natural boundaries while at the same time supporting a vast array of biodiversity.
Section 3: Methods Used in Prioritization of Conservation Network
3.1The Open Space plan in Durban
The D’MOSS project was an initiative undertaken 20 years ago in order to conserve open spaces and as such has resulted in a 5 phase framework plan:
3.1.1 The D’MOSS framework plan
Phase 1
1979 Metropolitan Open Space System (MOSS)
Undertaken by the Wildlife Society, a Metropolitan Open Space plan was produced which aimed to protect conservation worthy areas within and around the city of Durban (Ethekwini Municipality 2002).
Phase 2
1989 Durban Metropolitan Open Space System (D’MOSS)
Durban municipality in conjunction with the University of Natal produced a detailed ecological evaluation of the open spaces within the municipal area resulting in the Durban Metropolitan Open Space System (D’MOSS).
Phase 3
1999 D’MOSS Framework Plan
Open space regarded as having social, ecological and economic value and for these reasons, it needs protection. Environmental goods and services were quantified in order to calculate value of open spaces. Change in local government shifted the project away from conservation and ecological viability resulting in the need for the implementation of a socially, economically and environmentally sustainable open space system which was supported by the cities commitment to the international Local Agenda 21 Programme (Ethekwini Municipality 2003).
The open space was therefore re-conceptualised in such a manner that conservation was not the primary driving force. Data collection was facilitated and involved the digital mapping of the system using Geographic Information System (GIS). The spatial footprint of the system was also calculated.
Phase 4
2001 Ethekwini Environmental Services Plan (EESMP)
An increase in the boundaries of the Durban municipal area lead to an extension of the 1999 Open Space system (phase 3) culminating in the Ethekwini Environmental Services Plan (EESMP). Groups of environmental, planning and legal professionals were also appointed to recommend tools for the successful implementation as well as management of the open space system.
Open spaces were mapped using aerial photography and land cover was estimated. Development issues within the city however placed constraints on the size of the open spaces and land cover percentage for open spaces was refined in order to take into consideration social and economic issues.
Phase 5
2002 EESMP – Programme to secure the open space asset
Open spaces were remapped as a result of improved quality and coverage of available aerial photography in order to supply up to date information. Priority areas deemed most threatened by development were recognized so as to provide adequate protection and conservation.
3.1.2 The design of the open Space System
Open spaces were designed in such a manner that they would be well connected in order to supply the long-term supply of environmental goods and services within the DMA. Key open spaces identified included:
1. wide range open space types (e.g. grasslands, forests, etc),
2. corridors between open spaces to allow for flow of genetic materialand links to other sources of biodiversity (e.g Maputo land and Eastern Cape)
3. physical links along the coast linking marine sources of biodiversity.
These key open spaces were linked to pre-existing nature reserves, catchment areas, river corridors, land adjacent to riverine zones and coastal areas including estuaries and the seashore (Ethekwini Municipality 2003)
3.1.3Methods Used in Prioritization of Conservation Network
The results obtained from the 1999 open space project proved inadequate as the DMA underwent a 67% increase in size culminating in the eThekwini Environmental Services Management Plan (EESMP). The same sampling approach employed in 1999 was used in the 2001 project:
1. A set of ecosystem/habitat/land-use types relevant to the city of Durban was drawn. The land-use types were consistent in that they could be recognized on recent 1:5 000 aerial photography.
2. The city of Durban was then printed on black and white aerial pictures at a 1:5000 scale. From the aerial photography, areas that were recognized as having conservation priority were encircled.
3. Aerial photography resulted in the delineation of an open space covering 123 000 ha. Agricultural land and rural settlements were however excluded from this open space plan as it was felt that these areas could be adequately protected through means other than the open space system. This resulted in a reduced area of 76 000 ha which proved ideal in order to ensure long term support for the plan.
4. Areas selected were digitized and incorporated into a GIS database. The attribute files included fields for ecosystem/habitat/land-use types, area, priority or not, developability, etc.
As a result of the D’MOSS Plan, a network of open space conservation and recreation areas, linked by open space corridors wascreated.
3.2Gauteng Biodiversity Gap Analysis Project (BGAP)
3.2.1 Summary of Study Process
The study was planned around set project objectives which were outlined in key stakeholder meetings in order to contribute towards effective land use planning at the provincial as well as local government level. These project objectives were outlined in order to guide the development of provincial policies for the conservation and management of biodiversity in Gauteng (Pfab May 2003).
3.2.2Methodology used in Conservation Planning Analysis
The BGAP project followed the conservation planning protocol developed by Margules and Pressey (2000).
1. Biodiversity surrogates were selected in the province. These surrogates included all red data, rare plants, invertebrates, mammals, birds, reptiles and amphibians. Where species data was absent, a suitable habitat model was constructed which characterized a species habitat (Pfab May 2003).
2. Biodiversity data was collected and captured in a Biodiversity Information Management System (BIMS). This is a central database into which biodiversity data (specimen records) collected within the field, is assembled.
3. Quantitive, operational Targets were set for the conservation of biodiversity features in consultation with conservation and planning professionals. All conservation targets were based on conservation biology principles.
4. C-Plan, a GIS-linked decision support system, was used to determine the extent to which targets are met within existing protected areas. C-Plan was also used to locate additional areas to complement existing protected areas in achieving targets not met (Pfab May 2003).
5. Data input into C-Plan. Data from the BIMS was used to generate shape files which were then used as an input into the C-Plan Decision Support System (DSS). In general, two shape files were used per species, a shape file showing the confirmed distribution of the species and a shape file showing the distribution of a suitable habitat for a species. The biodiversity shape files were processed in such a manner that a species reference is attached to each site/land cover unit. A site database then generated units labeled with tags identifying the biodiversity features.
6. A Bio-Hotspot map was generated. A summed irreplaceability index was used for the analysis to discriminate between sites with an irreplaceability index of 1. The index was then weighted for vulnerability to give features with high irreplaceability ratings (Pfab March 2003).
7. Iterations of the conservation planning analysis were undertaken. At each iteration, all sites within the top 1% were selected and incorporated in to the bio-hotspot map. Iterations were terminated once bio-hotspots representing 10% of the land coverage of the province had been selected.
8. Conservation Plan. A site irreplaceability index was applied to all confirmed biodiversity features. All irreplaceable sites were selected and designated irreplaceable within the conservation map. A “minset” algorithm was then applied in order to meet conservation targets for the vegetation. The final analysis included the manual selection from all remaining sites but only those, which could be realistically achieved.