Trophic Dynamics and Integrated Pest Management
Alimentary and Trophic Relations
Alimentary and trophic relations are the relationships organisms establish with their living environment to obtain the matter and energy required for survival.
- Producers: These are autotrophic beings, such as plants, algae, and photosynthetic bacteria, that produce organic matter from inorganic matter with the help of light.
- Consumers: These are heterotrophic organisms that feed on organic material. They include herbivores, carnivores, and omnivores.
- Decomposers: These are heterotrophs that feed on the remains of living organisms or excrement, transforming them back into inorganic matter.
- Detritivores: These are small animals, like worms, that perform the complete transformation of organic matter if it is not already prepared for the decomposers.
Chains and Food Webs
A food chain consists of a number of organisms arranged in a line so that each one is eaten by the one following it. A food web is a set of trophic food chains connected to each other within an ecosystem.
Transfer of Energy in a Food Chain
Photosynthetic organisms produce organic matter through photosynthesis. This energy is distributed as follows:
- A part of it is degraded during respiration. The energy released is used for the functioning of the body and returns to the environment as heat.
- Another part forms debris, such as leaves and old branches, which move to the level of decomposers.
- The rest is stored in their bodies for use by herbivores. In the end, only a portion of the organic matter from producers becomes the actual biomass of herbivores.
Ecological Pyramids
Ecological pyramids are representations used to show how certain characteristics, such as production or biomass, vary across trophic levels when moving from one level to another. Each trophic level is represented by a rectangle. The base is reserved for the producers, with other trophic levels placed on top in an orderly manner.
Predator and Prey Dynamics
If there is an abundance of prey, the number of predators increases because there is little environmental resistance. Consequently, the number of prey decreases, which eventually leads to a decrease in the number of predators.
Competition and Ecosystem Balance
Two species that use the same resources cannot coexist in the same medium; the species with the best adaptation eventually eliminates the other.
When the Balance is Upset
A plague is any unwanted organism that interferes directly or indirectly with human activity. In natural ecosystems, pests are controlled by natural predators and a lack of resources, but sometimes this balance is broken. Pesticides are chemicals used to control pests by killing undesirable organisms. Depending on the target, these can be insecticides, herbicides, or fungicides.
Integrated Pest Control
The goal of integrated pest control is not to completely eradicate the plague, but rather to keep the population low enough to prevent economic loss. When a pest is detected, various biological controls are used:
- Introduce natural predators to control the pest population.
- Sterilize males so they compete with fertile ones, reducing reproduction.
- Mount traps to attract natural predators or the pests themselves, using toxic substances for targeted destruction.
Pesticides are only used in extreme cases.