1. Sunlight: Provides energy for plants to perform photosynthesis, the foundation of most ecosystems.

2. Water: Essential for all living organisms, playing a role in everything from cellular processes to weather patterns.

3. Air: Provides oxygen for respiration and carbon dioxide for photosynthesis, as well as other gases essential for life.

4. Soil: Provides nutrients and support for plants, and is home to a diverse community of microorganisms.

5. Rocks: Contribute to the physical structure of the ecosystem and influence the types of plants and animals that can thrive there.