1,Why do autotrophs always occupy the lowest level of ecological pyramids?
2.Explain how the growth of one population can bring about the disappearance of another population during succession?
3. Describe some common plants and animals from a tropical rain forest and a grassland biome?
1. Autotrophs, also known as primary producers, occupy the lowest level of ecological pyramids because they are the foundation of the food chain. Autotrophs are capable of converting inorganic substances, such as sunlight and nutrients, into organic compounds through photosynthesis or chemosynthesis. This ability allows them to capture and convert energy from the environment into usable forms for other organisms. Since autotrophs obtain their energy directly from the environment, they are the primary source of energy for all other organisms in the ecosystem. Consequently, they occupy the lowest level to reflect their crucial role in supporting the entire ecosystem.
To understand why autotrophs occupy the lowest level of ecological pyramids, you can consider the energy flow in an ecosystem. As energy moves through the food chain, there is a decreasing transfer of energy from one trophic level to the next. On average, only about 10% of the energy is transferred from one trophic level to the next, with the rest being lost as heat or used by the organism for its own metabolic functions. Since autotrophs are capable of capturing energy directly from the environment, they have access to the greatest amount of energy. As a result, they occupy the lowest level of the ecological pyramid, providing energy for the organisms at higher trophic levels.
2. The growth of one population can bring about the disappearance of another population during succession through a process called competition. Succession refers to the predictable and sequential changes that occur in an ecosystem over time. During the process of succession, different species establish and replace one another, leading to changes in the structure and composition of the community.
As a population grows, it may compete with other populations for limited resources, such as food, water, or space. This competition can lead to the displacement or elimination of weaker species, as individuals within a population that are better adapted or have a competitive advantage are more successful in acquiring resources. This success can result in the decline or disappearance of another population that is unable to compete effectively.
For example, in plant succession, fast-growing pioneer species may quickly establish and dominate an area with available resources. As these pioneer species mature, they shade out or outcompete other plants that require more sunlight or specific soil conditions, leading to the disappearance of those populations. This process continues as different species colonize and adapt to the changing environment, ultimately leading to the establishment of a stable and diverse community.
It is important to note that the disappearance of one population during succession is not always permanent. Populations can shift and change over time as the environment continues to evolve, allowing for new species to establish and compete.
3. Tropical Rainforest Biome:
- Common plants: Orchids, bromeliads, lianas, palm trees, ferns, epiphytes (plants that grow on other plants), and various species of tropical trees, such as mahogany and teak.
- Common animals: Toucans, macaws, hummingbirds, monkeys, sloths, jaguars, anacondas, tree frogs, butterflies, and a wide variety of insects.
Grassland Biome:
- Common plants: Grasses (such as buffalo grass, bluegrass, or ryegrass), wildflowers, prairie clovers, daisies, sunflowers, and sedges.
- Common animals: Bison, prairie dogs, antelopes, gazelles, zebras, ground squirrels, meadowlarks, hawks, foxes, snakes, and various insects like grasshoppers and butterflies.
It's important to note that both biomes contain a great diversity of species. These examples are just a few representative plants and animals found in each biome.