Ecosystem services – the array of benefits provided by nature – are the lifeblood of human societies, economies and identities around the world. For many rural populations, ecosystem services form an essential part of daily activities and longstanding traditions.
By Erin Bohensky, co-editor of the Gariep basin component of the Southern African Millennium Ecosystem Assessment (SAfMA), 2004
City dwellers may claim less direct dependence on ecosystem services, but they derive a variety of benefits from them, including “goods” such as food, water, fibre and pharmaceutical products, and “services” such as soil fertility and climate regulation that help to maintain a healthy, inhabitable environment. Ecosystems also provide cultural services through which people relate to, appreciate and enjoy nature. It is therefore in the best interest of societies as a whole to strive to maintain them. However, though their value is tremendous, ecosystem services are being seriously degraded, as recently demonstrated by the findings of the Millennium Ecosystem Assessment (MA)1, a four-year initiative to provide decisionmakers with relevant scientific information about the relationships between ecosystem change and various aspects of human well-being2. If current trends continue, these services are expected to deteriorate even further and are likely to compromise the achievement of the Millennium Development Goals. Understanding the links between ecosystem change and human well-being requires analysis not only at the global scale, but at finer scales – such as a river basin or village – where many key decisions about how to use and manage ecosystems are made. The Southern African Millennium Ecosystem Assessment (SAfMA)3 investigated these links in southern Africa. SAfMA adopted the unique multi-scale approach used in the MA, with assessments taking place at the scale of the whole region, in two large river basins and at several local community sites. Assessing ecosystem services at multiple scales provided an understanding of how different processes affect the availability of these services at each scale. For example, the availability of water in southern Africa depends on regional climate. However, in a given river basin, the availability of water may depend on factors including land use and national policy. In a village, factors such as local topography and adaptive practices may be at play. In addition, ecosystem processes do not conform to political boundaries; most southern African river basins are shared between two or more countries and wildlife migration routes frequently cross international borders. Thus, by focusing on regions and ecosystems rather than political units such as nations, provinces or districts, we obtain a richer and more comprehensive picture of the processes at work. SAfMA also employed the integrated approach used in the MA to explore the trade-offs between different services across time and space. Clear-cutting a forest today, for example, reduces the likelihood of benefiting from services that an intact forest can provide in the future, while the diversion of water to irrigate crops upstream may limit the availability of water for users and ecosystems downstream.
In terms of human well-being, southern Africa has some of the world’s poorest conditions when measured with standard indicators. Though the reasons for this are multi-faceted, poor human well-being is often linked to the degradation of or lack of access to ecosystem services. Some services are unable to ensure human well-being because of biophysical constraints – water is relatively scarce in the arid and semi-arid zones south of the Zambezi River, for example. However, many problems are due largely to governance issues such as ineffective or inappropriate policies. The SAfMA analysis revealed that policies that were implemented to secure benefits from ecosystem services at one spatial scale sometimes had negative impacts at another. Large irrigation projects in the Gariep basin intended to benefit South Africa’s commercial agriculture sector often displaced local communities and compromised their ability to maintain their livelihoods. This caused the displaced populations to put significant pressure on the environment in the areas to which they were relocated. Similarly, policies based on narrow sectoral objectives rather than on an integrated ecosystem approach often had unintended consequences. Massive dams stabilized the flow regime of the Gariep River, but the altered river conditions allowed a pest black fly species to proliferate, negatively affecting livestock productivity and, ultimately, imposing significant costs on the very farmers the irrigation projects were meant to serve.
It appears that some of the most promising ecosystem service management solutions are integrated strategies in which synergies between the maintenance of ecological integrity and the achievement of development objectives are present. The South African government’s Working for Water Programme, with the twin goals of poverty alleviation through job creation and eradication of invasive alien plants, is a notable example. However, the assessment highlighted the difficulty of implementing such initiatives in the absence of strong governance. It works both ways: the sustainable delivery of ecosystem services to people generally requires sound governance structures, while governance may be challenged when they deteriorate, due to increasing conflict over a declining resource base and a loss of options. The ability to choose among a variety of options when using such services as a source of one’s livelihood was shown to be fundamentally important. In fact, it is choice that decreases dependence on any one service and enables a more proactive, strategic approach to ecosystem management.
What does this mean for development and the Millennium Development Goals? SAfMA observed that the achievement of four of the Millennium Development Goals - reducing hunger, reducing child mortality, combating diseases and ensuring environmental sustainability - will face some serious challenges in the region if development plans do not explicitly address ecosystem services. Achieving the goals will require more than a passing mention of these services; it will demand a true appreciation of the links described above. Ecosystem services matter to everyone. The boundaries by which we live and govern our societies are invisible in terms of many of the physical, social and economic consequences of their degradation.
1. www.millenniumassessment.org 2. The MA regards human well-being as having multiple components: basic material income, health and nutrition, good social relations, environmental security and, fundamentally, freedom and choice. 3. Biggs, R., E. Bohensky, C. Fabricius, T. Lynam, A. Misselhorn, C. Musvoto, M. Mutale, B. Reyers, R. J. Scholes, S. Shikongo, and A.S. van Jaarsveld. 2004. Nature supporting people: the Southern African Millennium Ecosystem Assessment. Council for Scientific and Industrial Research (CSIR), Pretoria. Available at www.millenniumassessment. org/en/subglobal.safma.aspx