Chapter 45 & 46 Flashcards
Community
assemblage of many populations that live in the same place at the same time
Community Ecology
studies how groups of species interact and form functional communities
Species richness
number of species in each community–varies according to geographical range
Hypotheses to explain species richness
Species-Time
Species-Area
Species-Productivity
Diversity-Stability
Species-Time Hypothesis
Communities diversify or gain species with time
Species-Area Hypothesis
larger areas have more species b/c they can support larger populations & greater range of habitats
Species-Productivity Hypothesis
greater production of plants results in greater overall species richness
Diversity-Stability Hypothesis
species-rich communities are more stable than those with few species
Succession
the gradual & continuous change in species composition of a community following a disturbance (primary & secondary)
Primary Succession
succession on a newly exposed site that has no biological legacy in terms of plans, animals, microbes
EX: bare ground for volcanic eruption
Secondary Succession
succession on a site that has already supported life but has undergone a disturbance
EX: fire, tornado, hurricane, flood
Facilitation
species replacement facilitated (made easier) by previous colonists
Inhabitation
early colonies prevent colonization by other species
Tolerance
species replacement is unaffected by previous colonists
Ecosystems
relating to a community of organisms in an area plus the physical environment affecting that community