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
helps us to understand the geographic distribution of species and ecosystems
Gradient analysis
the organization of co-occurring and independently distributed species within a particular association
Open communities
ones in which the populations of numerous species overlap but are largely segregated from the distributions of other groups of species
Closed Communities
the process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities
Evolutionary convergence
Found Worldwide
cosmopolitan
areas with shared evolutionary history due to
geographic isolation
Biogeographic zone
A theory of succession whereby all species in the community work together to achieve stable climax community
superorganism
The independent evolution of similar features in species that are otherwise relatively unrelated
convergence
Convergence in carnivorous pitcher plant species, using DNA interpretation CASE STUDY
- Evidence of convergence
- Different pitcher plants that were unrelated become similar
despite differences among biogeographic zones, often unrelated species can look quite similar due to convergence
uses phylogeny
evidence of convergence: molecular phylogenetics
Simberloff study of insects on mangroves CASE STUDY
- studied insect colonization on mangrove islands in FL keys
- Equilibrium theory of island biogeography
- different mangrove islands reached an equilibrium with a species richness
-Small number of species: far island and small
-Large number of species: near island and large
Replacement of populations in a habitat through a regular progression to a stable state
Secession
Pioneer species to climax species in organic soils where life had previously been before a disturbance
Secondary Succession
“Resets” the successional clock
Disturbance
A series of stages of community change in a particular area leading toward a stable state
Sere
Stable community
Climax
Parts of the landscape that allow animals to move between larger areas of intact habitat
Corridor
The ability of a community to persist in the presence of perturbations, measured as the probability of extinction
Resilience
A measure of the ability of a community to persist in the presence of perturbations arising from weather, physical-chemical factors, other organisms, or human activities.
Stability
When a predator controls the abundance of a dominant competitor, allowing other competitors to persist and increasing diversity
Keystone Predation
Birds and mammals on mountains (Island biogeography) CASE STUDY
-island biography
Gilbert, et al. study of effects of corridors in moss on species richness of little critters CASE STUDY
-connecting patches increased migration and alpha richness (within patches).
- connecting patches also increased gamma diversity. So, it isn’t just the same species now getting to other patches, but the entire region supports more species.
-predators are more sensitive to fragmentation than consumers, as shown by decrease in % predators
-measure alpha and gamma diversity
Miller’s lichen study in New Mexico CASE STUDY
Yields Connell’s humped-shaped relationship of diversity with disturbance
- Test Intermediate Disturbance Hypothesis (Connell)
The rate at which plants assimilate the energy of sunlight
Primary Production
total energy (or carbon) fixed in photosynthesis per unit time
Gross Production
gross - energy (or carbon) lost by respiration (= biomass)
Net production
the study of how living systems
influence, and are controlled by, the geology and chemistry of the
earth
Biogeochemistry
Ratio of C, N, and P
Redfield Ratio
Assumption that the inputs to any ecosystem or compartment therein must equal the outputs plus changes in storage
Mass Balance
fundamental to ecosystem
biomass production and mass balance.
Decomposition
the ecological processes that
control the fluxes of energy, nutrients and organic matter
through an environment
Ecosystem Functions
ecosystem functions that occur within
an ecosystem that provide benefits to humans
Ecosystem Services
Jane Lubchenco Intertidal work on snails foraging on algae CASE STUDY
-Manipulated snail abundance to see if the abundance of grazers affected alga density and the types of algae present
-Snail numbers are determined by the abundance of green crabs
-Green crab number is determined by sea gull predation
-Lots of seagulls -> few crabs -> lots of snails -> lost of red alga -> low algal diversity
-Few seagulls → lots of crabs →few snails →enteromorpha (green) → low algal diversity
Hubbard Brook Whole Ecosystem CASE STUDY
-Vegetation strongly regulates nutrient cycling
-Studies nutrient cycling in a forest ecosystem
-Constructed dams on the site to monitor loss of water and minerals
-An example of long-term ecological research
-Results showed human activity can affect ecosystems
As the human population has grown, our activities have disrupted the trophic structure, energy flow, and chemical cycling of many ecosystems
Pitcher Plant Leaves as ecosystems CASE STUDY
- Ecosystem Ecology
- Looked at Carbon and Nitrogen cycle for pitcher plants communities
Livingston’s study of Apalachicola Bay
-Oysters in Apalachicola Bay show that maybe a combination of population and ecosystem-based approaches is the strongest approach
-Water flow was cut down to provide more water for agriculture, this led to the oyster fisheries crashing
-Some thoughts on why this happened are not enough freshwater, over harvesting, poor management, increased predators with increasing salinity
relating to or denoting the current geological age, viewed as the period during which human activity has been the dominant influence on climate and the environment
Anthropocene
a plant, fungus, or animal
species that is not native to a specific location, and which has spread to a degree
that causes damage to the environment, human
economy, or human health
Invasive Species
A species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental
Exotic or Introduced species
The hypothesis is that invasive species are successful because they have escaped their natural predators, herbivores, or diseases
Natural enemies hypothesis
Evolution of increased competitive ability allows them to outcompete native species (Explains lag time)
Evolution of competitive ability
The gradual and continuous spread of a population across the landscape into nearby areas
Jump and diffusion dispersal
a gradual change in the accepted norms for the condition of the
natural environment due to a lack of experience, memory and/or
knowledge of its past condition
Shifting baselines
McClenehan’s example of over-harvesting of fish in Florida CASE STUDY
- Looked at shift in fishing from groupers to mostly snappers
- Fishing can have long-term effects on size and species as well as catch
Kudzu, Asian Carp in the US, Zebra Mussels in North America, Fire ants, pythons, Lionfish CASE STUDY
- Zebra mussels originated in the black and Caspian Sea, first noted in North America in Detroit, and spread in the water. spread through “diffusion” and “jump dispersal”. Provide ecologists to study migration
-All invasive species that cause in some way harm to humans/ environments that benefit humans
When greenhouse gases in a planet’s atmosphere insulate the planet from losing heat to space, raising its surface temperature
GreenHouse effect
A period of time where the earth’s overall surface temperature is lowered enough that glaciers form at the poles and in mountainous
Ice Ages
When Co2 is absorbed by seawater resulting more acidic conditions and a lower abundance of carbonate ions
Ocean acidification
Plant Diversity on St.George island CASE STUDY
- Changing species richness with outside effects
CO2 on Mauna Loa CASE STUDY
- Temperature affects CO2 levels
- Evidence of Anthropogenic Climate Change
