Pippa Howard
2015-01-29
Category: General, Business & Biodiversity
As environmental challenges change and intensify, our means of addressing them must also adapt. In this instalment of our jargon buster blog series, Kristi Foster considers two strategies for environmental management that are rapidly gaining traction worldwide: ecosystem and landscape approaches.
Picture a species, a habitat and a natural resource. Under traditional environmental management, these might be considered as separate components of ecosystems. But in fact these components are inextricably linked through dynamic processes and interactions over space and time.
Take salmon in the Pacific Northwest, for example. When mature salmon return from the ocean to spawn in rivers, they provide an important food source for bears preparing for hibernation. As the bears gorge, they carry enormous quantities of fish from streams into forests, leaving the remains to decompose on the forest floor.
These discarded, nutrient-rich carcasses benefit many species, including millions of insects, small crabs, and larger species such as eagles and wolves. But salmon are also an excellent source of nitrogen, and the carcasses left in forests act as a powerful fish fertilizer, allowing coastal rainforest trees to reach incredible sizes.
Through this story of complex interactions, salmon species transport nutrients from the ocean, up rivers and into forests, nourishing entire ecosystems.
When human actions push these kinds of interactions out of balance – for example through pollution, overfishing, climate change or altered river flows – we jeopardise not only the salmon population itself, but also entire systems of life, including our own. These effects are almost impossible to understand and predict unless we consider how ecosystems function as a whole.
Managing land, water and living resources: an ecosystem approach
People are as much a part of ecosystems as the species and habitats that surround us. Our actions can have lasting impacts on the structure and function of ecosystems, which in turn affect our livelihoods, health, well-being and economies.
Unlike traditional environmental management approaches that focus on individual species, resources or habitats, an ecosystem approach considers people, nature and their interactions as part of a single system. This strategy focuses on maintaining the essential structure, processes and functions that keep ecosystems in balance and allow them to provide the ecosystem benefits on which societies depend.
Let’s take a closer look:
Ecosystem structure is the physical organisation of the living and non-living components of an ecosystem, including the species present and where they are found; the amount and distribution of soil, nutrients, water and other materials; and climatic conditions such as temperature, rainfall and light.
Ecosystem processes are the complex physical, chemical and biological interactions that link the living and non-living components of ecosystems and are critical to maintaining life on Earth. Examples include the cycle of water between the atmosphere and the earth’s surface; photosynthesis, in which green plants trap and convert solar energy into chemical energy; and decomposition, the breakdown of organic waste into nutrients by microbes.
Ecosystem functions result from ecosystem processes and provide benefits (such as supporting food chains and providing refuge and nursery grounds) to humans and other species. These functions include the ecosystem services on which human lives, livelihoods and well-being depend – services such as clean water supply, pollination and spiritual inspiration.
Ecosystem approaches use the best available scientific knowledge of ecosystem structure, processes and functions over space and time to manage human activities in complex, dynamic systems. This achieves more effective and lasting management decisions than single-component or single-sector approaches.