Ecosystem Dynamics: Matter, Energy, and Population Changes

Ecosystem Dynamics: Matter and Energy Flow

Flow of matter and energy in the ecosystem: Environmental inorganic compounds and organic matter are processed in photosynthesis, then returned to the environment and can be reused by producers. Plants transform solar energy, which is stored and then ceded to the environment, where it cannot be used by living things.

Types of Pyramids

Energy: Each rectangle represents the energy stored. The rectangle representing producers is always larger. Each trophic level provides sufficient energy to support the level above it.

Biomass: These pyramids are constructed using data on the amount of biomass at each trophic level. These pyramids can sometimes be reversed.

Numbers: These rectangles represent the number of individuals at each trophic level and can be reversed.

Carbon Cycle

Carbon cycle: Carbon is the most important element in living matter. Its path is as follows: plants, algae, and some bacteria capture carbon dioxide through photosynthesis and transform it into organic carbon compounds. This carbon circulates through all trophic levels through feeding. A portion of the organic molecules is returned to the environment through respiration. The remains of bodies are buried and transformed into sediments, naturally enriching the environment. Carbon dioxide is also released from the burning of plant materials and volcanic eruptions.

Population Changes

Changes in populations: Populations have characteristics that isolated individuals do not possess. These characteristics change in response to changing environmental conditions.

Population Growth

Exponential growth: In an environment with unlimited resources, population growth as a function of time results in a J-shaped growth curve.

Carrying Capacity

Logistic growth in the population: The carrying capacity (K) is the maximum population that a given habitat can sustain long-term without degrading.

Interacting Populations

Interacting populations: Density is a factor that controls the size of a population. As density increases, so does environmental resistance, and vice versa.

Predator and Prey

The predator and prey: If there is abundant prey, environmental resistance for the predator decreases, and their number increases. This can result in a decline in the prey population.

Integrated Pest Control

The integrated pest control: This involves introducing natural predators to regulate the pest population, sterilizing male pest insects and releasing them to compete with fertile males, and setting traps with pheromone attractants.