Final Flashcards
Definitive Host
host where parasite reaches sexual maturity
Intermediate Host
host where parasite may grow, develop, or reproduce asexually (also called secondary host)
2 types of parasites
microparasites:
reproduce in host, found in gut, short generation time, usually need high host densities to persist (eg fungi, virus, bacteria)
Macroparasites found on cavities, on surface on body, may use more than 1 host, long generation time (eg parasitic worms, lice,fleas, ticks) -endoparasites (inside) -ectoparasites (outside)
Vertical transmission
infection passed from parents to offspring
-herpes simplex 2
horizontal transmission
all other mechanisms of transmission
- direct: host to host
- indirect: usually a third party involved (vector)
Vector
organism that carries the parasite between host
Parasites can impact host on 3 levels
- Individual: reproduction, mortality
- Population
- cause mass mortalities
- depress growth rates and population size
- can drive population cycles - Communities
- by influencing competition
Disturbance
is abrupt change in the ecosystem, community, or population structure and resource availability, substrate availability, or the physical environment.
Succession
directional change in community composition or structure over time following a disturbance
Primary succession
after catastrophic disturbance, in newly formed habitats (no plants or organic soil)
secondary succession
after disturbance that remove plants (some/all) but soil and nutrients remain (moves away from climax)
Pioneer species
able to survive as first colonists
-often facilitate colonization by additional species
climax community
final group of species the end point of succession
-often inhibit colonization by additional species
Endemic species
are those found only in a single area
Species-Area Curve
- bigger islands have more species than small islands
- species richness increases with island area
Define S=c*A^z
c= constant of species/area z= slope z= 0.32 (~0.3 most islands)
What is z for species area curves on continental areas?
z= 0.17 (~0.15-0.24 for land areas)
Island biogeography
- dynamic equilibrium theory that explains species richness of islands
- island richness determined by colonization and extinction rate
- richness increase with size (more habitat, less extinction)
- richness decreases with isolation (less likely to be colonized)
Metapopulation
- collection of subpopulation of 1 species
- proportion of sites occupied determined by colonization and extinction rates at each site
Rescue Effect
Unoccupied patches or disappearing subpopulations can be rescued by immigration from other patches
-unoccupied patches are necessary for metapopulation to persist
Source-Sink Metapopulation
- Sources r>0
- Sink r<0
- difference in patch quality
- sinks persist b/c they are resupplied with individuals from sources
Ecosystem
all of the interacting parts of the biological and physical worlds
Ecosystem ecology
The study of natural systems from the standpoint of the flow of energy and cycling matter
Energy conservation
energy can be neither created or destroyed (can be transformed)
-energy can be transformed via photosynthesis
mass conservation
mass can neither be created or destroyed (can be recycled)
Mass balance approach
Input= Outputs + Storage
Gross PPR
rate at which energy is captured and assimilated in an area
Net PPR
rate at which energy is assimilated and converted into producer biomass in an area
Ecological efficiency
% of net production moving from one trophic level to the next
-energy per unit area/ unit time (g/m2/yr)
Assimiliation efficiency
how much energy % is assimilated compared to the amount ingested
Production efficiencies
the % of energy ingested that is used for growth (GPE gross production efficiency)
Autochthonous
self production of energy
(big rivers)
-lots of primary production
allochthonous
other energy production get it from outside sources
-(small streams)
-low primary production
Redox reaction
photosynthesis reduces C to store energy
-respiration oxidizes C (kreb cycle) to power cells
Habitat Heterogeneity
larger islands have more species on them because they have more different habitat types on them –> more niche spaces to occupy
Productivity
is the rate of generation of biomass in an ecosystem
-measure of amount of energy available
Spatial subsides
resources that pass from one ecosystem to another increasing productivity of the recipient ecosystem
- can be active/ passive
- organisms, material, energy
Mycorrhizae
are symbiotic relationships that form between fungi and plants. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis.
N2 fixing
is a process by which molecular nitrogen in the air is converted into ammonia (NH 3) or related nitrogenous compounds in soil.
-cyanobacteria can do this
Eutrophication
excessive nutrients inputs in aquatic ecosystem –> algal blooms –> bacteria digest dead algae, depleting water of oxygen –> die offs of fish and seagrass
Major drivers of biodiversity loss
- exploitation
- invasive/exotic species
- land modification
- appropriation of freshwaters
- nutrient polluation (eutrophication)
- contaminant pollution
- stratospheric ozone depletion
- climate warming/change
Native species
- live in place of origin
- endemic or indigenous
Introduced species
- non-native, alien, exotic
- required human intervention to persist (cows)
invasive species
- introduced or other
- pervasive in new environment
Intermediate Disturbance Hypothesis
-species diversity is highest at intermediate levels of disturbance
