Cycling materials and biodiversity Typeit

Ecosystems contain organisms at different trophic levels all interacting. Food chains always start with producers, which are photosynthetic organisms that convert light energy into biomass, and proceed upwards from , which eat the producers. The abundance and distribution of organisms in an ecosystem can be sampled along a gradient using quadrats along a . Stable ecosystems will have a high . The abiotic components of an ecosystem are also important in its functioning; for example, is essential for life and is cycled through precipitation and evaporation.

Ecosystems and the species they contain are easily affected by changes to the environment. Most scientists argue that humans are a major contributor to the global warming problem, which is increasing the overall temperature of Earth via the effect. Many human activities add atmospheric gases such as to the atmosphere through transport and industry, exacerbating this effect and having negative effects on biodiversity. This also threatens our own food .

Humans also affect the planet in other ways, through dumping waste, which causes , and through our land use. For example, many peat bogs, areas that act as sinks, are being destroyed to produce garden , and deforestation is occurring on a huge scale to provide resources and clear land for agriculture. Many people are now working to reduce the negative effects we have on biodiversity; for example, by introducing programmes to prevent the extinction of endangered species, and by encouraging and reuse of resources rather than adding them to landfill.