Test 3 Flashcards
An assemblage of populations that interact with one another, directly or indirectly
Community
All interacting parts of the physical and biological worlds
Ecosystem
Group of species living in the same place
Association
Species in the same community utilizing resources in the same way, often competitors
Guild
the study of the composition and structure of plant
communities
Phytosociology
number of different species that are represented in a given community
Species Diversity
Describes relative abundance of different species
Species Evenness (More equal relative abundance)
Number of species in a community
Species Richness
Tree Diversity patterns at different latitudes CASE STUDY
Holdridge life zones diagram is a graphical classification of zone ecosystems on earth that shows the relationship of the mountains and lowland vegetation based on latitude, elevation, precipitation and air temperature
Miller’s pitcher plant organisms CASE STUDY
-results: Effects of Resources on Species Richness
-Long term historical effects
-Dispersal, migration and extinction:leaves grow and die constantly, so the entire community has to periodically disperse to and re-establish in new leaves
-Productivity/climate:productivity is more prey, which increases bacteria as well as rotifers and protozoa. Significant bottom-up effects on some species
-Competition: we do know protozoa and rotifers compete, which seems to reduce diversity
-Predation:increasing the number of predators primarily decreases rotifers, but has little effect on protozoa or bacteria. Modest top-down effect. No keystone effect
Miller’s Coastal dune plants CASE STUDY
-As with most communities, we find that some of the species are very common, but most are very rare.
-can be used to look at rank abundance patterns
(Within Habitat diversity) number of species in local, small areas of uniform habitat
Alpha Diversity
(Between Habitat diversity) The variation in species composition from one habitat to another within a region. This is really a measure of variation in diversity, not diversity directly
Beta Diversity
A measure of the numbers and relative abundances of species across a region that includes numerous local habitats
Gamma Diversity
Interaction of food chains
Trophic Web
Based on energy obtained by plants and algae
Green Food Web
A community whose basal species consist solely of detritivores
Brown Food Web
Emphasize the feeding relationships among organisms
Connectedness webs
Show energy flow between resource and consumers
Energy flow webs
Food web that reflects the importance of each species in maintaining the integrity of the community
Functional Web
Species that get eaten by nothing else in the food web
Top predator
Species that feed on nothing within the web (Usually plants)
Basal Species
Species that feed at more than one trophic level
Omnivores
The number of actual interactions divided by the number of possible interactions
Connectance
When removing a top predator causes the next trophic level to decline, the level below that to increase, etc.
Trophic Cascade
The average number of links or interactions per species in the web
Linkage Density
A cycle in which a species feeds upon itself
Cannibalism
Gary Polis’ complex desert food web CASE STUDY
-No Trophic Levels in complicated webs
- attempted to construct
the full food web for a
“simple” real community
in a California desert. - Food webs are too complicated to be viewed as a simple chain of interactions with discrete trophic levels
The branch of biology that deals with the
geographical distribution of plants and animals.
Biogeography
A boundary line between Asia and Australia that separates organisms by their biogeographic origin
Wallace Line
Found in one region
Endemism or endemic
Drives Geographical location of continents
Plate tectonics