Presently, conventional development does not adequately incorporate functional ecosystems into development design. Largely due to the intangible nature of most ecosystem services, functional ecosystems have not been directly identified as valuable and are, therefore, often ignored in economic decision frameworks. This has resulted in the degradation and loss of functional ecosystems and ecosystem services as the value and the associated costs of lost ecosystem services are not accounted for. The valuation of ecosystem services is a means by which ecological costs and values can be adequately represented in urban planning and decision-making processes. However, using current valuation methods, ecosystems are continuously being valued for their aggregated ecosystem service values and not for the value of their ability to resist/recover from disturbances and continue proving goods and services over time. The Swan Lake watershed case study was utilized to show that the estimated ecosystem service values are not risk adjusted to reflect the functional condition of an ecosystem. Specifically, based upon the current valuation estimates alone and without reference to the functional condition, the estimated ecosystem service values for the Swan Lake study suggest that the watershed is in a good (proper) functional condition, when in-fact, the overall health of the watershed is in a poor condition of health and its resilience to disturbance is low. Furthermore, the estimated values do not reflect the loss of ecosystem services due to past urbanization and agricultural activities. Because the estimated values do not provide the critical information decision makers require, the valuation of the functional condition of ecosystems is recommended. Due to the complexity involved in valuing the functional condition of an ecosystem, the integration of ecosystem valuation methods and ecosystem evaluation assessments is proposed and explored. In the context of post-urban planning and development, the proposed approach has immediate application as it would provide effective financial arguments for the preservation and restoration of ecosystems as well as facilitate more informed decisions in managing existing urban ecosystems for their function rather than ecosystem services. In a pre-development application, there exists a opportunity wherein an ecosystem’s functional condition could be valued as part of an integrated development design and planning process (IDP). The British Pacific Properties (BPP) Rodgers Creek development is used as a case study to describe how the proposed approach could be incorporated into the integrated design and planning (IDP) process. By clarifying the ecological tradeoffs between various land-use/development scenarios using a sieve analysis, the proposed approach could help a design team render more informed judgments regarding the functional condition of ecosystems and the value of the ecosystem services. The proposed approach also contributes to a much needed business case, which demonstrates that when urban developments are planned using an IDP process, where the landscape informs the design, there can be greater financial reward to the developer, community and municipality

Herbivores have a significant influence on their environment. Factors that influence herbivore distribution in a landscape are important for conservation. Artificial water provision is one such factor, with water sources being focal points of herbivore activity. Variation between herbivore utilisation of different waterhole types and habitat integrity surrounding the different waterholes is assessed in this study. Correlations are drawn between herbivore utilisation and habitat integrity to quantify the impact that artificial waterholes have on the landscape. A scoring system is devised to investigate the various factors affecting vegetation around artificial waterholes. Results show that there are significant variations between herbivore utilisation for different artificial waterhole types, as well as significant variation in habitat integrity surrounding the different waterhole types. Distance between waterholes and drainage lines, and utilisation by specific herbivore species have a significant impact on habitat integrity - specifically affecting veld condition and disturbance observed on woody plant species. A habitat score that was created by combining data from both the herbaceous and woody layers is not affected by waterhole type, distance from waterholes, or the different herbivore species utilising the different waterhole types. Earth dams have the greatest impact on surrounding vegetation and are the most utilised waterhole type. Closures of earth dams are not recommended due to their importance to herbivores. Less utilised waterhole types are also important, mitigating the impact of herbivore damage to vegetation at earth dams. / Environmental Sciences / M. Sc. (Nature Conservation)

Municipal commonage in South Africa offers previously disadvantaged, landless residents access to both direct ecosystem goods and services (EGS) that provide additional income options and indirect social and cultural services. Given that EGS production is a function of ecosystem health, it is imperative that commonage land be managed to maximize current local benefit streams while ensuring future options through the maintenance of natural ecosystem functions. The payments for ecosystem services (PES) model potentially offers an opportunity for contributing to local economic development while providing fiscal incentives for environmentally sustainable natural resource management. PES depends on the demonstration of quantifiable changes in EGS delivery due to improvement in or maintenance of high ecosystem health that are a verifiable result of modifications in management behavior. This thesis therefore compared spatial variations in (i) ecosystem health and (ii) nine direct and indirect EGS values derived from natural resources on the Bathurst municipal commonage and neighboring Waters Meeting Nature Reserve (NR) to explore how different land use intensities affect ecosystem health and the resulting provision of EGS. The results indicate that the total economic value of annually produced EGS on the study site is nearly R 9.8 million (US$ 1.2 million), with a standing stock of natural capital worth some R 28 million (US$ 3.4 million). Nearly 45% of the total annual production is attributed to Waters Meeting NR, with roughly 34% from the low use zone of the commonage and the remaining 22% from the high use zone. Of the total annual production value on the study site, roughly 59% is derived from indirect (non-consumptive) uses of wildlife for the study site as a whole, though this proportion varies from 25% in the high use zone of the commonage to 94% on Waters Meeting NR. The two largest annual production values on the study site derive from ecotourism (R 3.5 million, US$ 0.4 million) and livestock production (R 2.6 million, US$ 0.3 million), suggesting that while increased production of indirect EGS could generate significant additional revenues, especially on Waters Meeting NR and in the low use zone of the commonage, direct (consumptive) EGS will likely remain an important component of land use on the commonage. A PES project to support the adoption of silvo-pastoral practices could provide positive incentives for improved land use practices on the commonage and potentially be financed by conservation-friendly residents of the Kowie River catchment and/or increased ecotourism revenues from Waters Meeting NR. Allowing carefully designed and monitored local access to natural resources within Waters Meeting NR could also reduce pressure on commonage resources. Together, these approaches could lead to a more sustainable subtropical thicket landscape and ensure that critical natural resources remain available to support local livelihoods in the long-term.

Comment mesurer la dégradation de la nature, son état de "santé", afin de déterminer l’amortissement de son utilisation, non-enregistré dans les bilans des nations? Mon travail de thèse sur la « comptabilité écosystémique » du bassin versant du Rhône est une première expérimentale sur une nouvelle méthodologie intégrable aux outils encore incomplets des comptabilités nationales de type PIB. Consommer du capital écologique, nos ressources renouvelables, sans l’amortir revient à créer des dettes écologiques. L’objectif de la comptabilité écosystémique est de produire un outil d’aide à la décision permettant d’éviter la dégradation nette des écosystèmes par des politiques publiques informées par la science. L’outil produit des bilans écologiques basés sur des informations géographiques et mesurés en termes physiques, permettant d’effectuer des modélisations et simulations afin d’estimer l’internalisation des externalités (Figure). J’ai élaboré divers indicateurs synthétiques relatifs aux fonctions des écosystèmes et de leur intégrité, pour calculer le potentiel écologique du bassin versant du Rhône. Le diagnostic comptable est assortie d’une description spatialisée des changements observés afin de mieux saisir leur pertinence. L’outil est susceptible d’aider les différentes entités territoriales à se positionner sur la gestion de leurs ressources renouvelables stratégiques (eau, sols, biomasse, infrastructures et services écologiques) dans le contexte d’un ordre mondial en transformation: il s’agit des enjeux géopolitiques majeurs en matière de sécurité et souveraineté alimentaire et énergétique, dans leur lien avec la santé publique. / How to measure the degradation of nature, its "health" condition, to determine the depreciation of its use, not recorded in the balance sheets of the nations? My thesis work on the "ecosystem accounting" of the Rhone river basin is an experimental first on a new methodology integrable with the still incomplete tools of the national accounts of the type GDP. Consuming ecological capital, our renewable resources, without amortizing means the creation of ecological debts.The goal of ecosystem accounting is to produce a decision support tool to avoid the net degradation of ecosystems through science-informed public policies. The tool produces ecological balances based on geographical information and measured in physical terms, making it possible to perform modelizations and simulations in order to estimate the internalisation of externalities (Figure). I have developed various synthetic indicators relating to the functions of ecosystems and their integrity, to calculate the ecological potential of the Rhône watershed. The accounting diagnosis is accompanied by a spatial description of the changes observed in order to better understand their relevance. The tool is likely to help the various territorial entities to position themselves on the management of their strategic renewable resources (water, soil, biomass, infrastructures and ecological services) in the context of a changing world order: major geopolitical issues in terms of security and food and energy sovereignty, in their link with public health.

Freshwater in adequate supply and quality is vital to life on Earth; however, land-based activities such as development, agriculture, mining and industry, and their associated contaminants, pose a major threat to the quality of freshwater water resources and health of aquatic ecosystems. The upper uMngeni catchment draining into Midmar Dam is a strategically significant water resource, supplying clean drinking water to the eThekwini, uMgungundlovu and Msunduzi municipalities. The quality of this resource is under threat from current land-based activities such as Mpophomeni settlement and agriculture and emerging threats in the form of the Khayalisha social housing project. Monitoring sites were established in varying land use types in three sub-catchments of the upper uMngeni, to assess water quality and ecosystem health impacts of current land uses on Midmar Dam. A suite of physical, chemical and biological water parameters were sampled in conjunction with SASS5 bio-monitoring to assess the associated impacts. Water quality and ecological condition were highest in forested land use and upstream of Mpophomeni where natural land cover and sparse settlement occurred. Marked declines in water quality and ecological condition were observed at areas under commercial agriculture, indicated predominantly by rises in nutrient concentrations and declines in the SASS5 indices. The most notable declines in water quality and ecological condition were observed at sites downstream of Mpophomeni settlement as a result of severe sewage contamination, indicated by high E. coli counts. Nutrient concentrations downstream of Mpophomeni settlement ranged from mesotrophic to hypertrophic, with nitrogen to phosphorus ratios indicative of nitrogen limitation. Ecological condition remained in the ‘seriously/critically modified’ category over the study period. Nutrient loads produced by Mpophomeni are the highest of all the land uses, followed by that of commercial agriculture; both should be viewed as a concern, more so when viewed in terms of their compound effect on Midmar Dam water quality. Current water quality draining the commissioned Khayalisha social housing development area is good and although not natural, is of no contamination concern to Midmar Dam. Results indicate that with current land use activities, urban development and agriculture pose a potential threat to the quality of Midmar Dam resource and that further development in the form of the Khayalisha social housing project may replicate impacts already prevailing in Mpophomeni, whereby a principle water resource may be threatened by eutrophication. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

The 28-month study assessed the impacts of five syntopic medium-sized mammalian browsers and one fire event in a woodland savanna in the Matobo Hills, Zimbabwe. Aspects of herbivory, mechanical pressures, seed dispersal and nutrient cycling were investigated for three species of small antelope (common duiker [Sylvicapra grimmia]1, klipspringer [Oreotragus oreotragus] and steenbok [Raphicerus campestris]) and two medium-sized species (bushbuck [Tragelaphus scriptus] and greater kudu [T. strepsiceros]). Focusing on Burkea africana2 woodland, in a system that does not include elephant (Loxodonta africana), effects of browsing antelope on woody and herbaceous vegetation development were investigated using exclusion plots. Browsers regulated woody plant cover (measured as basal stem area), with smaller antelope having a greater impact than larger species. This was linked to feeding height, feeding selectivity and mechanical pressures (e.g. twig breakage and trampling). Fire caused an initial reduction in above-ground standing biomass, but in the presence of fauna, pre-fire equilibria were attained within 15 months. In antelope exclosures, herbaceous biomass increased and woody biomass decreased following fire. Responses by woody vegetation to browsing varied among species, with highly palatable species typically exhibiting compensatory regrowth. Woody species richness and abundance (especially of palatable species) increased in the absence of browsers, but species richness of the herbaceous layer was promoted by moderate disturbance (trampling or fire). Faecal deposition behaviour, primarily the use of latrines by small antelope, resulted in localised soil enrichment within defended territories. Decomposition rates (and therefore return of nutrients to the soil) varied among species and seasons, due to defecation site selection, accessibility to decomposers and desiccation rates of faecal pellets. Controlled seed germination experiments indicated that ingestion by small antelope enhances germination rates of large, hard-seeded fruits such as Sclerocarya birrea. However, germination of savanna seeds may require multiple cues. This study demonstrated the critical roles of small antelope in ecosystem functioning, and highlights the importance of the less visible impacts of frequently overlooked smaller mammalian herbivores. Perturbations to the faunal community, especially small antelope, are predicted to have substantial impacts on woody plant cover.