rewsf Flashcards
Law of tolerance
most spp perform best w/ a narrow environmental conditions
- principal of allocation
matric forces
water tendency to adhere to walls
negative pressure
decrease plant water potential, created by water evaporation from leaves
Optimal foraging
predicts what/when/where animals eat
selection of energy based on minimal loss
hermaphadite
share male and female costs, low mobility, overlap in resource demands
distribution limits
geographical area restricting a spp distribution due to biotic and abiotic factors
3 patterns od survival tables
- cohort life table
- tracks survival and mortality patterns based on birth year
- most reliable
- hard to get data - static life table
- record age of death of large # of individuals
- hard to estimate age of death - age distribution
- distribution of age groups in ppn
- estimate survival by looking at proportions in each age
survivorship curves
type 1
graph = high mortality among older gen
- large invertebrates
type 2
graph = linear (-)
- birds, snakes
type 3
graph = die young
- seaturtle, invertebraes
Dispersal
increase or decrease in ppn density b/c of immigration/emmigration
impacted by:
- climate change
- food supply/dispersal range
dispersal down river/stream
Dispersal down river
- current pushes stream dwellers downstream
- to compensate dwellers move upstream
1. streamline bodu
2. dorso-ventrally flat
3. microbes adhere tp surfaces
colonization cycle = ppn maintain w/ interplay between up/down shifting
metapopulation
ppn of subppn that are connected w/ habitat requirements
- limited gene exchange = decrease heterozygosity, bottleneck
- maintained w/ immigration`
BIDE dynamics
Birth Immigration Death Emmigration
biotic factors = density dependent
abiotic = density independent`
geometric and exponential ppn growth
geometric
- successive gen differ in size by constant ratio
- single gen per year
- gens no overlap
exponential
- overlapping ppn
- continuous
- instinsic rate of increase = per capita rate under idea conditions
logistic ppn growth
- biotic factors decrease rate of growth
- s shape curve
- k = carrying cap
- zero net ppn growth
- birth = death
- low ppn = low growth rate
intravariation of spp
variation within spp
r selection
ppn growth rate, large value, fast
r spp
large ppn, fast growth, habitiat disturbance
k spp
small ppn, large, habitat near carrying cap (k)
ammensalism
spp1 negatively affected
spp2 neutral
neutralism
both spp neurtrally affected
forms of competition
- interface = direct, agressive, between individuals
- exploitative = indirect or direct, scarce resources
e.g tree grow faster where older tree root area less - interspecific
- intraspecific
competition evidence
ppn slow at increased density (k maxed)
- logistic growth model
e.g. self-thinning trees when more biomass and less density
density lowers faster than biomass increases (for plants)
Lotka-Volterra model
- for interspecific
- resource down, ppl up
- increase resource competition
coexistence
- interspecific must be less than intra in both spp
coexistance factors
1 spatial heterogeniety in strength of competition
2 variation in spp competitive ability
3 competitive equivalence
4 non-equalibrium conditions (unstable)
herbivory and plant defense
herbivoury decrease plant growth and reproduction but also increase growth in grasses w/ feces
- resistance = decreased likelihood of damage
- tolerance = withstand damage -overcompensation: form of tolerance where plants recover from herbivory and grow better or reproduce more after moderate levels of damage
plant chemical defence
- constitutive = continous regardless of environment
- induced = rapid increase in response to damage
snowshoe hares and predators
- abundance cycle driven by plants/overppn
- food supply = shortage in winter (peak density), heavy browsing induce plant chemical defence, lowering quality
- non consumptive effects - up cortisol down reproduction
- lynx max out at intermediate snowshoe ppn
- coyote increase at highest density
Lotka-volterra predator prey model
- assume exponential growth w/out predator
- add term for predator
- critique
1. exploiter not subject to carrying cap
2. assume immediate response in other ppn
3. no non-consumptive effects
predatory avoidance
- camo
- coloration
- aposematic = bright and toxic/distaste
- batesian mimicry = not toxic, look similar to toxic
- mulleriam mimicry = sharing color w other toxic - refuge
- hide in space
- protection in #
- predator saiton
- safety in size (elephant)
facaltative mutulaism
not needed for survival
obligate mutualism
depended on for survival
Herd immunity for disease
decreasing pathogen ppn can go extinct
- vaccine susceptible
- host availibilty lowers
- large enough vaccinated ppn = immunity acheived
disease ecology compartment models subppn
1 susceptible individuals
2 infected
3 immune
disease transmission
- direct = host infected
- indirect = host surface
- horizontal = partial gen
- vertical = parent to offspring
mutualist-exploiter continuum
mutualisms are exploitative interactions that happen to be reciprocal
- most are facultative
- more common: involve set of spp not single pairs
cheating in mutualism
- both ways
e.g. nector robbers: pollinators that exploud energy rich nector but do not move pollen
mimic flowers: mimic appearance and odor and induce wsapss to pseudocopulate by male wasts
evolution of mutualism
will evolve where benefit>cost
- successive mutualist give and receive
- unsuccessive = give no receive
- non mutualist = neither
Bergmann’s rule
increase in size moving closer to poles
- surface to body ratio
law of minimum
growth limited by scarcity
j-curve
abundant resources, exponential growth
Why number of trophic levels are limited
- energy loss through levels
- heat loss
- low ecological efficiency
where does ecosystem energy go
energy entering an ecosystem is primarily captured by primary producers (through photosynthesis) and is transferred to consumers and decomposers as it flows through the trophic levels
mechanisms of ecosystem biodiversity
- Complementarity Niche theory - Production is highest in an ecosystem being most fully exploited.
- Facilitation: Some species (spp) enhance the growth of others.
- Sampling effect: Assumption that the functions of communities with low species evenness are driven by dominant species.
Wetland value
- flood control
- shoreline = storm protection
- climate change mitigation
laws of thermodynamics
1 energy can’t be created only transformed
2 head will move from warm to cool, entropy increases in closed system
importance of plant diversity
- species richness (diversity) is positively correlated with primary production
- more diverse = higher primary production
phosphorus cycle
- importance: Vital for ATP, RNA, DNA, and phospholipid molecules. Essential for energy transfer and genetic processes in living organisms.
- global cycle: Lacks a significant atmospheric pool.
- soil: Exists in chemical forms often unavailable to plants, so they use miccorhizae
- Phosphorus Movement:
1. Released through the weathering of rocks.
2. Absorbed by plants and recycled within ecosystems.
3. Washed into rivers and eventually to the oceans, where it remains dissolved.
nitrogen cycle
- importance: structure and dunction of organisms
- major atomospheric pool, few organisms can directly utilize
- nitrogen fixers: cyanobacteria, soil bacteria on legumes convert N₂ into forms usable by plants (e.g., ammonia).
- Agricultural practices have increased nitrogen fixation (e.g., synthetic fertilizers like NH₄).
- Ammonia (NH₃) and nitrate (NO₃⁻) are absorbed by plants and transferred through food webs.
- denitrification = Nitrogen is returned to the atmosphere as N₂ through anaerobic processes by bacteria.
carbon cycle
- importance: Central to organic molecules and compounds like carbon dioxide (CO₂) and methane (CH₄).
- processes: photosynthesis, respiration
- In aquatic ecosystems, CO₂ dissolves in water and forms equilibrium with bicarbonate (HCO₃⁻) and carbonate (CO₃²⁻), some of which precipitates as calcium carbonate and is buried in sediments.
- carbon resovoirs:
1. Fast-cycling carbon: In the atmosphere, organisms, and surface layers of the ocean.
2. Slow-cycling carbon: In soils, fossil fuels, and carbonate rocks, remaining sequestered for long periods.
rate of decomp
- Temperature and moisture positively influence decomposition rates.
- Soil fertility and nutrient availability (e.g., nitrogen, phosphorus) are crucial.
- High lignin and low nitrogen content slow decomposition.
Decomp in Mediterranean Woodland Ecosystems:
- Decomposition was influenced by moisture and chemical traits like nitrogen content and toughness of leaves.
- Higher decomposition rates at Monte La Sauceda (wetter site) compared to Doñana Biological Reserve.
Decomp in Temperate Forest Ecosystems:
- North Carolina site had faster decomposition due to higher nitrogen availability and temperature compared to New Hampshire.
- Leaves with high lignin decomposed slower, confirming the lignin-to-nitrogen correlation.
Decomp in Aquatic Ecosystems:
- Higher nitrate and phosphorus concentrations increase leaf decomposition rates.
- Leaves with high lignin (e.g., beech) decompose slower than those with lower lignin (e.g., ash).
