Energy Flow in Ecosystems - Module 2

Energy Flow in Ecosystems

• The sun is the ultimate energy source for the biosphere, providing energy in light and heat forms.
• Plants utilize sunlight through photosynthesis, leading to energy fixation termed primary production.
• Primary production represents the initial stage of energy storage in ecosystems, aiding in the creation of biomass.

Food Chain

• A food chain illustrates the linear path of energy and nutrient transfer among organisms.
• Primary producers (photoautotrophs) convert light energy into chemical energy, while chemoautotrophs utilize chemosynthesis in darkness.
• Energy stored by autotrophs is transferred to heterotrophs (consumers).
• Secondary consumers feed on primary consumers, forming multiple interconnected food chains.

Food Web

• Food webs represent complex interconnections, reflecting that consumers usually feed on multiple species rather than a single food source.
• The presence of various predators for each species highlights the intricate relationships within an ecosystem.
• Two primary types of food webs exist:
  • Grazing Food Web: Comprises larger plants and animals commonly seen.
  • Soil-based or Detritus Food Web: Involves organisms that feed on decomposed organic matter.

Energy Pyramid

• The energy pyramid visually represents energy levels available at different trophic levels in an ecosystem.
• Energy decreases significantly at each successive level, typically only about 10% is passed on from one level to the next.