Week 1: What is an ecosystem?
Throughout this course you will be considering these overarching questions:
- What is the importance of understanding ecosystems?
- How do they work?
- How crucial is their conservation?
But first, what constitutes an ecosystem and how is an ecosystem defined? Consider the habitats shown in Figure 1. Are they individual ecosystems or groups of ecosystems? Could there be different ways of defining ecosystems?
By the end of this first week you will be able to explain how an ecosystem is defined, in terms of energy flow, and be able to define and use terms which are introduced in the videos and text and apply them to new situations and examples where appropriate.
There is more than one way in which an ecosystem can be defined. In the following video Dr Mike Gillman highlights the difference between two schools of thought. One definition is that an ecosystem is an area where groups of organisms experience similar conditions.
Alternatively, an ecosystem is a living system of energy transfer, a whole complex of organisms living together, linked by energy transfer. The key difference is that ‘area’ defines one, whereas ‘energy relationships’ define the other.
Before we can begin to tackle the larger issues of ecosystems and how they have been compromised by human intervention, we must understand what is meant by ‘ecosystem’. As you watch the video ‘What is an ecosystem?’, consider the following questions, which we will discuss in the next section:
- What is the key difference between the definitions?
- What is the working definition of ‘ecosystem’ that we are going to use in this course?