Exam 2 Vocab Flashcards
Mutation
Deletions, insertions, duplication, & rearrangements od chromosomal parts (rare but important)
MUST OCCUR IN GAMETES OR GAMETE PRODUCING CELLS
Genetic drift
Changes in gene frequencies due to random sampling effects (greatly affects small populations due to random loss of alleles)
Migration
Gene flow between populations via movement of propagules
ACTS AGAINST ADAPTATION TO LOCAL ENVIRONMENTS
Natural selection
Changes in gene frequencies due to ecological interactions
OFFSPRING HAVE HERITABLE ADAPTIVE TRAITS THAT INCREASE SURVIVAL AND REPRODUCTION
3 conditions for evolutionary change
- Phenotypic variability (genetic, environmental, developmental)
- Fitness differences (fecundity, fertility, survivorship)
- Heritability of phenotypic differences
Directional phenotypic selection
Individuals with an extreme trait value have highest fitness (evolves in 1 direction)
Stabilizing phenotypic selection
Individuals with intermediate trait values have highest fitness
Disruptive phenotypic selection
Individuals with high & low trait values have high fitness, intermediate traits start to die out (caused by disturbance, rapid evolutionary change, coevolution)
THIS CAN EVENTUALLY LEAD TO SPECIATION
Correlational phenotypic selection
Where the pattern of selection for 1 trait depends on the value of another trait
Phenotypic plasticity
Variation in the phenotype of a single phenotype caused by environment, individuals change forms to adapt to conditions
AmeriFlux Network
Managed sites for measuring ecosystem fluxes of CO2, water, & energy (NPP)
found in N, Central, and S America
Pool
Stored quantity of a material within an ecosystem
Flux
flow of materials across different pools within an ecosystem
Turnover time
How rapidly materials move through a system (ttl mass ÷ flux)
Retention time
Average length of time a material resides in a pool (inversely related to turnover time)
Net Primary Productivity (NPP)
Rate of C transformation from CO2 into organic forms
Largely driven by plant biomass (as temp ^, NPP ^)
Net Ecosystem Production
Net accumulation of carbon per year by the entire system
Intraspecific competition
competition of natural selection for fittest individuals within a species through evolution
-increases with density if resources are constant
-if resources increase, density can increase
-competition effects are more evident over time
Interspecific competition
Competition with other species
Apical meristems
Small region at tip of root (apex) in which all cells are capable of repeated division (where all root tissues are grown)
Axillary meristems
Located in the leaf axil and can establish new growth axes
Perennating organ
Buds at soil surface to protect from certain disturbances
Cryptophytes
have tubular buds underground for more protection from disturbances/climatic changes
Rhizomes
horizontal underground stem branching into lateral shoots and adventitious roots at intervals
Genet
genetic individual (like Quaking Aspen clonal forests)
Ramet
potentially physiologically independent unit of a genet
Phalanx plant spatial pattern
ramets spatially clumped (like phalanx formation from ancient Rome)
Guerilla plant spatial pattern
ramets dispersed in space (uses local arrangement in convenient places where they can “pop” up as possible if other plant spp are disturbed/die
Plant phenology
timing/schedule of growth & reproduction during a year
Agamospermy
Asexual Production of Seeds (without meiosis, new seeds are clones of parents, relatively widespread: dandelion, hawkweed, stinging nettle, etc)
Determinate inflorescence
terminal flowers bloom first—less responsive to resource additions (cyme, umbel, disk florets)
Indeterminate inflorescence
maximum number of flowers not fixed, very responsive to additional resources—will produce more flowers (axillary flowers, racemes, spikes, corymbs)
Zoochory
seed dispersal by animal—directional but cost of creating structure to attract and/or interact with animals
Autochory
self-dispersal of seed—cost of creating dispersal structures, short-distances (jewelweed, traveling moss, etc)
Anemochory
wind dispersal—cost of creating many propagules, not directional
-dispersal amount can depend on shape, weight, wings, how many seeds are produced, etc)
Hydrochory
water dispersal of seed (ex: coconut, mangrove, lotus)
Semelparous (monocarpic) strategy
reproduction as a single event per lifetime (only once) ex: bamboo
Iteroparous (polycarpic) strategy
multiple reproduction events per lifetime –most plant spp
Ruderals
well-adapted to disturbance but not particularly to stress of competition
COMPADRE database
fast-slow continuum (traits on right of graph take longer to do—survivorship, age at sexual maturity, generation time, etc).
revealed additional patterns beyond simple fast-slow continuum—reproductive strategy explained nearly as much variation among spp as fast-slow continuum—shows complexity of plant traits over generations? If plants start using different reproductive strategies or growth patterns to adapt to environment
Masting
fruiting synchrony across years and locations (independent of plant density)
Sessile organisms
biological property of an animal describing its lack of a means of self-locomotion
Pando
a single clonal patch of male quaking aspen (abt 40,000 genetically identical tree stems connected, 106 acres, 13 mil lbs, age could be up to 14,000 yrs)
Life tables
estimated list of vital rates
Transition Matrix Model
use life cycle graphs to write them, shows what is needed for plant to transition to the next stage (looking at probability of transition)—formula for each life stage
To calculate future population vector: transition Matrix X current population vector
Integral Projection Model (IPM)
better than matrix models for modelling structured pops with greatly varying demographic rates. Can become complicated
A) Probabilistic events—may or may not happen to each individual (flowering or survival, etc)
B) Regression models—for predicting plant growth and seed production
Sortie Forest Community Model
individual tree growth, survival, and reproduction as function of environment (light, water, temp, nitrogen)
-can determine extinction probabilities related to total relative environmental stochasticity
Species Interaction Matrix
looking at ways species interact, positive interactions: mutualistic traits, neutral traits amensalism?, commensalism, etc, and negative traits like competition
Self-thinning Law (Yoda Law)
initial plant density neg affects final individual biomass (linear relationship bt density & weight on a log-log scale) W = cN-3/2 (W = weight, N = survivor density, c = constant)
Hutchinson’s niche
multidimensional hypervolume of ecological conditions where spp can occur
Fundamental niche
range of all conditions in which a plant spp can persist
Competitive Exclusion Principle
“one spp, one niche”
Centrifugal Model
of plant community organization along environmental gradient
-spp occur along multiple gradients, competitive hierarchies among spp, each spp competes best in its core habitat
Granivores
seed consumers
Grazers
consuming low growing plants
Browsers
eating leaves of trees/shrubs
Trichomes
important physical defenses for plants (sharp ‘hair-like’ thorns to prevent herbivory)
Zoophily
Animal pollination.
-Many different pollinators with symbiotic relationship with plants (1 gets food source, other gets pollen dispersal & outcrossing of genetics)
Frugivory
seeds pass through guts of dispersal agent (may facilitate germination)
Myrmecochory (and elaiosomes)
ants disperse seeds & consume nutritious seed appendages (aka elaiosomes)
Free-living Nitrogen-fixers
photosynthetic cyanobacteria, heterotrophic decomposers—typically live in anoxic conditions in little pockets of soil
Ectomycorrhizae
doesn’t really pass through cell walls
Arbuscular myccorhizae
does pass through cell walls
Epistasis
When gene expression depends on the properties of alleles at other loci.
Ex: flower pigmentation occurs through multiple steps resulting in different enzymatic release
Narrow-sense heritability
Calculated as just a fraction of phenotypic variance that is due to additive genetic variance
Broad-sense heritability
Calculated as the total genetic variance
Cline
A gradient in allele frequencies or another population characteristic (can be small-scale or at larger geographic scales)
Epigenetic effects
Changes that do not involve alterations of the DNA base-pair sequence
Transgenerational plasticity
Environment can indirectly affect phenotype of individuals in subsequent generations
Realized niche
Range a species is actually found in
Tiller
node on a rhizome that can produce new leaves and roots
Somatic mutations
mutations in ordinary cells making up the body of the plant, rather than in gametes—can also lead to variation that is subject to natural selection
Spatial autocorrelation
resemblance as a function of distance
- can result from genetic drift, although it can also be caused by other processes.
ecotypes
describes populations of a species from different habitats or locations that possess genetically based differences in appearance and function.
-Ecologists usually use the term ecotype to refer to such differences that appear to be adaptive.
allopatric speciation
differentiation that happens in populations that are geographically distant from each other
Parapatric speciation
differentiation that occurs in adjacent populations
sympatric speciation
differentiation that occurs within a single population
Taxonomic species
defined by shared morphological characters or DNA sequences
Cryptic species
organisms that appear to belong to the same species and yet are reproductively isolated from each other
Polyploidy
the duplication of the entire set of chromosomes, resulting in two or more copies of the genome in each cell
productivity
the capture of sunlight energy and its storage in carbon bonds
Gross Primary Production (GPP)
the total energy (or carbon) fixed by producers in an ecosystem
Standing biomass
The sum of all organic matter in living vegetation
Ecosystem Respiration (Re)
the sum of all respiration occurring by the living organisms in a specific ecosystem.
Saprophytic fungi
rely on nonliving organic material for their carbon and energy
Throughflow
rainwater that passes through the canopy and travels down the surface of tree trunks, carrying dissolved ions leached from the plant surfaces
Potential evapotranspiration (PET)
the maximum amount of water that would be lost to evapotranspiration in a particular place if water were freely available in the soil and plant cover were 100%.
depends on energy available to evaporate water
Actual evapotranspiration
equal to the amount of water that enters the system in precipitation minus the amount that is lost in runoff and percolation to groundwater (the amount of water stored in living systems is minimal relative to these amounts).
Leaf Area Index (LAI)
the surface area of the leaves from which water is evaporating
-often considerably greater than the surface area of the ground
radicle
the structure that will develop into the root structure
stolons
(runners)—branches or stems that spread at or just above the surface of the soil and generate ramets at nodes touching the ground.
bulbs
underground rosette stems that store nutrients
suckers
meristematic buds on some of their near-surface roots capable of generating new stems and leaves.
bulbils
tiny bulb-like organs vegetatively produced in inflorescences or leaf axils
serotinous
bonded shut with resins and open only when temperatures are sufficiently high
Raunkaier system
evolutionary adaptation over many generations that stems from adaptive phenotypic plasticity
inclusive fitness
a measure of how well that individual passes on its genes as well as how well its relatives pass on the genes they share with that individual, weighted by how closely they are related.
vernalization
when plants require a period of cool or cold temperatures, before flowering
imbibition
uptake of water by seeds
degree-days
the sum of temperatures experienced over some period of time (important for determining timing of leaf expansion)
recruitment
the combination of processes leading to new individuals
size hierarchy
unequal size distribution, affects resource access
-individuals compete for resources, a few plants get bigger and therefore higher resource use, many more plants will be small. Some of the smallest plants will die due to lack of resources
facilitation
positive interaction among plants
regeneration niche
differences among species in the conditions and circumstances required for germination and establishment
nurse plants
a mature plant of a different species, and often a different growth form, than the juvenile. They can enhance the establishment of juvenile plants in a variety of community types.
sclerenchyma
a plant tissue with lignified cell walls that surrounds the vascular bundles carrying food and water in young stems, and the waxy cuticle on the surface of leaves, which both reduces water loss and protects against fungal attack.
collenchyma
supporting tissue made of living elongated cells with irregularly thickened walls
hemiparasites
can live either as parasites or independently
obligate parasites
can survive only by parasitizing other plants
virulence
used both to mean the ability of an infectious agent to produce disease, and a measure of the degree of damage inflicted by a pathogen on the host organism
arbuscule
The body of the AM fungus which grows as a delicately branched structure inside the cortical cells of the roots and in the intercellular spaces between root cells, with hyphae (fungal strands) extending out several millimeters or more into the soil
amensalism
a biological interaction where one species causes harm to another without any benefit to itself (competition and antibiosis)
commensalism
a long-term biological interaction in which members of one species gain benefits while those of the other species neither benefit nor are harmed
mutualism
a biological interaction in which both species benefit
Stress Gradient Hypothesis
Choler et al. 2001—look at diff spp in open vs sheltered locations and diff elevations—over all spp at all sites, strong shift from neg effect of neighbors at low and sheltered sites to positive effects at high and exposed sites
-facilitation happens at different locations in various amounts (esp high elevations, stressful situations)
