This extract discusses the flow of energy in an ecosystem, primarily derived from the sun and captured by photosynthetic plants. The energy moves through different trophic levels, with some energy being lost as heat and through respiration.
As energy is transferred from one trophic level to another, there is a progressive decrease in the amount of energy passed on. The organisms in the ecosystem contribute to the recycling of energy back to plants through nutrient cycles.
The extract also explains the concept of food chains, including grazing food chains and detritus food chains. It mentions examples of food chains involving plants, animals, and decomposers.
Additionally, the extract covers topics such as food webs, decomposers, pyramids of numbers and biomass, and population estimation methods. It concludes with a discussion on plant adaptations to different habitats, including xerophytes, mesophytes, hydrophytes, and halophytes.