Autochthonous and allochthonous production

North American Photosynthesis

All biotic communities depend on a supply of energy for their activities. In most terrestrial systems this is contributed in situ by the photosynthesis of green plants - this is autochthonous production. Exceptions exist, however, particularly where colonial animals deposit feces derived from food consumed at a distance from the colony e.g. bat colonies in caves, seabirds on coastland - guano is an example of allochthonous organic matter dead organic material formed outside the ecosystem . In...

Unitary and modular organisms

Duckweed Lifecycle

Our 'ecological fact of life', though, implies by default that all individuals are alike, which is patently false on a number of counts. First, almost all species pass through a number of stages in their life cycle insects metamorphose from eggs to larvae, sometimes to pupae, and then to adults plants pass from seeds to seedlings to photosynthesizing adults and so on. The different stages are likely to be influenced by different factors and to have different rates of migration, death and of...

Detritivores and specialist microbivores

Images Detritivores

The microbivores are a group of animals that operate alongside the detritivores, and which can be difficult to distinguish from them. The name microbivore is reserved for the minute animals that specialize at feeding on microflora, and are able to ingest bacteria or fungi but exclude detritus from their guts. Exploitation of the two major groups of microflora requires quite different feeding techniques, principally because of differences in growth form. Bacteria and yeasts show a colonial...