C1  Species and Communities

big ninja

Essential Idea:

Community structure is an 

emergent property of an ecosystem


  • The distribution of species is affected by limiting factors
  • Community structure can be strongly affected by keystone species
  • Each species plays a unique role within a community because of the unique combination of its spatial habitat and interactions with other species
  • Interactions between species in a community can be classified according to their effect
  • Two species cannot survive indefinitely in the same habitat if their niches are identical


  • Distribution of one animal and one plant species to illustrate limits of tolerance and zones of stress
  • Local examples to illustrate the range of ways in which species can interact within a community
  • The symbiotic relationship between Zooxanthellae and reef-building coral reef species


  • Analysis of a data set that illustrates the distinction between fundamental and realized niche
  • Use of a transect to correlate the distribution of plant or animal species with an abiotic variable