Gwybodaeth Modiwlau

The ecosystem is the basic unit of study in ecology and many important relationships between organisms, both plants and animals, with their abiotic environment are best explored at this level. Initially, a holistic approach is adopted with an analysis of a simple ecosystem, the arctic tundra, to show how our knowledge of this system has evolved and to describe the basic relationships that exist between its various components. It is necessary, however, to place the concept of the ecosystem within the context of the ecological hierarchy, which considers ecological organisation from the individual level up to the biosphere.
A range of abiotic factors are reviewed and considered in relation to biotic factors including: herbivory, predation and competition. Predation is one factor that limits population numbers from exponential growth. Similarly, competition for resources has an equally important effect. In addition, a study of resource utilisation by species helps us to understand their position within ecological systems, generally defined as the niche. Within its distribution, however, a species will often show specific adaptation to particular situations; examples of such ecotypic variation will be discussed.
We next consider future challenges to ecosystems and biodiversity including habitat loss, responding to global climate and the need for conservation. This includes the importance of conserving biodiversity at a range of scales, from genetic diversity to biomes and ecosystems. Including ecological and evolutionary theory underpinning conservation and practical approaches to conserving species.