Edexcel IGCSE Biology: Double Science 复习笔记 4.1.1 Key Terms in Ecology

Edexcel IGCSE Biology: Double Science 复习笔记 4.1.1 Key Terms in Ecology

Key Terms in Ecology


  • There are several key terms that we use when referring to the various different components of an ecosystem and their levels of organisation:
    • A population is defined as a group of organisms of the same species living in the same place at the same time
    • A community includes all of the populations living in the same area at the same time
      • Within a community, each species depends on other species for food, shelter, pollination, seed dispersal etc
      • If one species is removed it can affect the whole community
      • This is called interdependence


    • A habitat is the place where an organism lives
      • E.g. badgers, deer, oak trees and ants are all species that would live in a woodland habitat


    • An ecosystem is defined as all the biotic factors and all the abiotic factors that interact within an area at one time
      • Biotic factors includes all the living components such as plants and animals
      • Abiotic factors includes all the non-living components such as light intensity, mineral ions, water availability
      • Ecosystems can vary greatly in size and scale
        • A small ecosystem might be a garden pond
        • A large ecosystem might be the whole of Antarctica







Levels of organisation in an ecosystem