Defined simply as “the benefits people obtain from ecosystems”, ecosystem services have become a hot topic in recent years. The Millennium Ecosystem Assessment demonstrated the many ways that ecosystem services contribute to human well-being. Their important role in sustaining livelihoods and improving the wellbeing of people is now widely recognized. For example, ecosystem services range from provision of food and water to flood mitigation and improvement of water quality to less tangible benefits such as contributions to local cultures. Though it is often difficult to put a monetary value on ecosystem services (some are literally irreplaceable), economists are increasingly demonstrating the value of a wide range of different services.
Ecosystem services are especially important for millions of poor people, particularly those living in rural communities of developing countries. Many rural communities depend directly on a range of ecosystems services for their livelihoods and well-being and, due to isolation and a paucity of resources, may have few substitutes or alternatives to the services provided by ecosystems if they are lost, degraded or access is obstructed. Furthermore, many of the world’s poorest people live “close to nature”, meaning they are extremely connected to the ecosystems that surround them and, thus, they gain the most immediate benefits from the services that they provide.
As economies become more industrial, the direct links between well being and ecosystem services change and become more disconnected. In rich, developed countries, people rely on plumbing and filters to deliver water rather than “unmodified” ecosystem services derived directly from rivers and lakes. They rely upon packaged foods rather than wild harvested plants and animals, so there is a greater “distance” between the ecosystems that provide services and the people that benefit. It is debatable, but possible that, their rich lifestyles are reliant on as many or more, ecosystem services than the poor.
People in wealthier areas are often able to physically buffer themselves from some of the vagaries of nature, through housing and other infrastructure. Such built infrastructure is not always reliable, as was seen when the levies failed to prevent flooding during Hurricane Katrina, but it does generally enhance peoples’ safety and well-being. In contrast, many of the world’s poorest people are directly exposed to nature’s extremes, such as cyclones or other hazards, and at the same time are heavily dependent on nature’s ability to regulate those extremes. For example, through the coastline protection functions provided by mangroves and wetlands.
Economic development is to a large extent dependent on modifications of the natural environment. Human ingenuity is used to alter the natural environment in ways that improve peoples’ wellbeing. Thus, human capital/technology is used to complement or substitute natural ecosystem services, to effectively distribute ecosystem services from one place to another. For example, food stocks are enhanced through agricultural practices and flows are enhanced by transporting food around the planet. Only in this way is it possible to feed nearly 7 billion people. However, there are often negative impacts from industrial agriculture that undermine many natural ecosystem services.
While man-made infrastructure replaces and often improves on some ecosystem services, it inevitably alters the environment. These modifications to the environment can cause considerable changes to ecosystems and the services they provide. For example, a dam affords artificial water storage and often improves flow regulation for people: decreasing flood flows and increasing dry season flows. For those in societies who utilize the water and/or energy that the dam provides, the dam enhances natural ecosystem services. However, dams modify the environment, not just upstream where the river and surrounding valley is flooded, but also downstream where natural river flows are altered. These changes can affect other ecosystem services, often resulting in unintended, negative consequences for those dependent on the services. For instance, because they block migration routes and modify the flow regimes to which fish have adapted, dams often have an adverse impact on fisheries, thereby undermining the livelihoods of poor fisher-folk.
The challenge in understanding exactly how ecosystem services contribute to poverty reduction is that social and economic development – particularly, lifting people out of poverty – have traditionally been achieved by significantly altering ecosystems to provide services that meet the needs of people in ways that are faster, more predictable, and/or more abundant than nature provides. However, in amplifying one or a few target services to meet people’s daily needs (such as those that support food production or energy production), other services that are important for human well-being over longer-time scales (such as climate regulation, disaster regulation, pollination, and/or disease regulation) may be degraded or compromised. The value of these latter services is often appreciated only when they are lost or compromised and when lives and economies have been severely impacted by extreme events, for example.
One critical, related question is how different degrees and types of dependence on ecosystems and the services they provide influence societies’ resilience to stressors and unexpected events. In general, the more diverse a system (i.e. the greater the range of functions and ecosystem services provided by it), the more resilient it is to either natural or human-induced change. One risk of human modification of ecosystems is that increasingly modified, often less diverse, systems, are less able to cope with unforeseen or rarely occurring events. For example, converting mangroves to aquaculture may in the short-term benefit coastal communities by increasing food production and providing employment, but the longer term risk is that because natural defenses have been lost the coastal communities will be devastated by floods associated with coastal storm surges. This is a particular worry as climate change increases the frequency of extreme events.
Clearly, the relationship between ecosystem services and development is multi-faceted and complex. Economic development is a prerequisite for lifting people out of poverty. However, ultimately all of us are dependent on ecosystem services – they keep the planet fit for life - and so safeguarding them is vital. Sustainable development requires that we achieve a better balance between economic development and sustenance of essential ecosystem services to support resilient social-ecological systems. We don’t yet know how to achieve it, but it is imperative that we get this balance right!
For more information on ecosystem services and resilience, a cross cutting theme in the Water, Land and Ecosystems program, click here.