THE ECOSYSTEM: INTERRELATIONSHIPS BETWEEN
Ecology: The study of the interrelationships between living organisms and the living and non-living FEEDING RELATIONSHIPS AMONG SPECIES. The Food . A niche includes the physical space in which they live, how they use the The interaction among organisms within or between overlapping niches can be which helps them evade predators, and are exposed to more diverse feeding. In every ecosystem, organisms are linked through feeding relationships. . matter and energy flow between organisms that are likely to live in that ecosystem.
This would give a top-heavy pyramid if numbers were used. Using biomass gives a more accurate picture. These relationships are frequently disturbed by humans.
Removal of species e. The larvae are predated by birds such as blue tits and larvae and pupae are parasitized by a number of small wasps. One wasp Pleurotropis amyntas parasitises the larva of other parasitic wasps. A simple food chain involving this species would be However, by adding in links to more food chains we can begin to show that like most species the Holly leaf miner is almost certainly part of a complex food web.
The v-shaped flap on the leaf shows that this larva has been eaten by a bird The pin-sized hole on the leaf shows that the larva has been parasitised by a wasp Dissection of this mine has revealed the empty pupal case of a holly leaf-miner - the adult fly will have emerged successfully In a collection of holly leaves it is easy to count the number of leaves infected by the fly.
It is also not difficult to identify leaves: Remember this is based on numbers and evidence of cause of death.
A much clearer picture would be available if it were possible to measure biomass at each stage of the food chain. Green plants that carry on photosynthesis.
Producers are termed auto-trophs because they are self-nourished — they do not depend on other species to feed. During photosynthesis, plants capture light energy with their chlorophyll and use it to convert carbon dioxide and moisture absorbed from air into sugar chemical energy.
Oxygen is released as a by-product Every major ecosystem has its particular green plants that carry on photosynthesis and release chemical energy carbohydrates, protein etc. Species that feed directly on producers plant-eating species.
They are also called Herbivores. Species that feed on primary consumers. Secondary and higher order consumers are called Carnivores. Tertiary and higher level Consumers: Species that obtain their nourishment by eating other meat-eating species.
Species that obtain their nourishment from eating both plants and animal species. Also called Omnivores 3. They are the final link in the food chain. Comprise of organisms that feed on dead matter and break it down to release chemical energy back into the soil for plants to re-use them.
A food chain or food web comprises a sequence of organisms through which energy and nutrients are taken in and used up. A food chain in a wet meadow could be: Food chains begin from producers to consumers and the major feeding levels are called Trophic Levels.