The correct option is (c) 1 and 3 only.
Explanation
In a forest ecosystem, biotic components (plants and animals) exhibit complex interrelationships. These interactions are essential for energy flow, nutrient cycling, and the sustainability of the ecosystem. This interdependence ensures the survival and propagation of species within the community.
Statement-wise Analysis:
- Statement 1 is Correct: Animals rely heavily on plants for survival. Herbivores consume plants as their primary food source, initiating the food chain. Additionally, forests provide physical habitats, such as canopy cover and tree hollows, which serve as shelter and protection for various animal species against predators and harsh weather.
- Statement 2 is Incorrect: Plants are not completely independent of animals for reproduction. Many plant species depend on animals (insects, birds, bats, and mammals) for pollination, which is crucial for fertilization. Furthermore, animals play a vital role in seed dispersal (zoochory), helping plants spread to new areas and reducing competition among seedlings.
- Statement 3 is Correct: Nutrient cycling is a key aspect of ecosystem interdependence. Animal excreta (droppings) and decaying animal bodies are broken down by decomposers (bacteria and fungi). This process releases essential nutrients, such as nitrogen and phosphorus, back into the soil, which plants then absorb through their roots for growth.
Key Takeaway:
Forest ecosystems function through a cycle of mutual dependence where plants provide energy and habitat, while animals facilitate plant reproduction (pollination/dispersal) and contribute to nutrient recycling.