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...

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...

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...

Dispersal of seeds and pollen

Types Dispersal Seeds And Fruits

Very many plant species use animals to disperse their seeds and pollen. About 10 of all flowering plants possess seeds or fruits that bear hooks, barbs or glues that become attached to the hairs, bristles or feathers of any animal that comes into contact with them. They are frequently an irritation to the animal, which often cleans itself and removes them if it can, but usually after carrying them some distance. In these cases the benefit is to the plant which has invested resources in...