In which of the following ecosystem pyramids are always upright ?

Options

A. Tree ecosystem
B. Lake ecosystem
C. Grass land ecosystem
D. All of above

Answer

**Step-by-Step Solution:**

1. **Understanding Ecosystem Pyramids**: Ecosystem pyramids are graphical representations that illustrate the distribution of various entities like numbers, biomass, or energy across different trophic levels in an ecosystem.

2. **Types of Ecological Pyramids**: There are three main types of ecological pyramids:
- Pyramid of Numbers: Represents the number of organisms at each trophic level.
- Pyramid of Biomass: Represents the total biomass of organisms at each trophic level.
- Pyramid of Energy: Represents the total energy available at each trophic level.

3. **Characteristics of an Upright Pyramid**: An upright pyramid has a broad base (representing producers) and a narrow apex (representing top consumers). This shape indicates that the number, biomass, and energy of producers are greater than those of consumers.

4. **Examples of Ecosystems**:
- **Grassland Ecosystem**: Typically shows an upright pyramid because the number, biomass, and energy of producers (like grasses) are greater than those of herbivores and carnivores.
- **Aquatic Ecosystem**: Often shows inverted pyramids due to the high biomass of consumers (like zooplankton) compared to producers (like phytoplankton).
- **Tree Ecosystem**: Can also show inverted pyramids as a single large tree may represent one producer, while many consumers (birds, insects) depend on it.

5. **Conclusion**: The grassland ecosystem is the one where the ecological pyramids (number, biomass, and energy) are always upright. In contrast, aquatic and tree ecosystems can have inverted pyramids.

**Final Answer**: The ecosystem where the pyramids are always upright is the **grassland ecosystem**.

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