plant eco exam 2 previous questions

T/F - surface runoff represents a major pool in the global water cycle.

F

T/F - trichomes often serve as a defensive mechanism against herbivory.

T

T/F - plant species that use anemochory for seed dispersal typically have large seeds with lower dispersal capacity

F - anemochory = wind!

T/F - nitrification refers to the process in which ammonium (NH4) is converted to nitrate (NO3)

T

T/F - a ramet refers to the group of ganets that originated from a single seed

F - ramets are not genetically distinct, while ganets are!

T/F - according to Grime’s CSR theory, competitive effects prevail where resources are abundant, and the environment is not too stressful.

T

T/F - even-aged plant populations in monocultures do not have a size hierarchy

F

T/F - biennial plants are often semelparous

T - semelparous = monocarpic

T/F - the exponential growth model is density dependent

F

Which correctly describes the findings of Reich and Hobbie (2013)?

the ability of plants to sequester excess CO2 is limited by N availability

What is an important implication of the findings of Doak and Morris (2010) that different vital rates showed opposite trends across different populations?

A caution against using only one vital rate to access plant response to environmental change (eg, climate warming).

How do seed banks function as an adaptive strategy in plant phenology?

They enable temporal dispersal via seed dormancy until favorable conditions arise.

Which is not a hypothesized reason for masting?

ensurance of a consistent annual seed production

An interaction where one species benefits and the other is not affected (+/0) is called?

Commensalism

How does plant species identity influence soul carbon pools and fluxes?

differences in root traits, litter quality, and microbial associations among plant species can alter carbon inputs, decomposition rates, and overall soil carbon cycling.

when are IPMs more appropriate to use than matrix models?

when plant demographic rates vary continuously with plant size

Which is an example of the coevolutionary arms race between herbivores and plants?

monarchs feed on milkweed, sequestering its toxins to deter predators

in a tropical rainforest, which would you expect to see the most water loss from?

evapotranspiration

The maximum number of individuals the env. can support

carrying capacity

reproductive rates and chances of survival of individuals in a population

vital rates

group of undifferentiated plant cells

meristem

rande of environmental values in which a species is physiologically capable of growing

fundamental niche

potential reproductive capacity of an organism measured as the number of gametes or propagules it produces

Fecundity

type of seed dispersal where seeds are spread by animals

zoochory

horizontal underground stem branching into lateral shoots and adventitious roots at intervals

rhizome

environmental range within which a species is found

realized niche

chemical inhibition of the growth of one organism by another

allelopathy

positive interactions among plants

facilitation

the ___ model of plant community org. describes that species are distributed across multiple environmental gradients, with strong competitors dominating in core habitats.

centrifugal

animals (like squirrels) that consume plant seeds are called ____

granivores

purple foxglove only reproduces once in a lifetime, this is called ____

monocarpic/semelparous

other than humans, ___ are the only organisms with a substantial effect on the global water cycle

plants

among all ecosystems, __ ecosystems store the greatest amount of soil carbon

wetlands

an unexpected fire can introduce randomness and increase the chance of extinction in small populations - this is called ___

environmental stochasticity

studies done in yellowstone found that grazing ___ plant diversity and richness

increased

symbiotic fungal associations with plant roots where the fungus does penetrate the plant cell wall is called ____

endomycorrhizal

what is size hierarchy

no average size within each age class, rather large variation that allows some individuals to dominate (usually larger)

why might size hierarchy arise and occur

germination times or early access to resources compounding

how does size hierarchy affect population dynamics

can cause self-thinning, mortality of smaller plants that are outcompeted, intraspecific competition

forest clearance betwen tropical rainforest and shrubland? why?

clearance in tropical rainforests causes aridification due to loss of evapotranspiration from trees, resulting in less precipitation

clearance in shrubland results in desertification, loss of shade leads to heat stress

what is a nurse plant? example?

nurse plant - plant that helps facilitate the growth of a nearby juvenile

ex - saguaro cacti and shrub tree, tree provides shade from sun, facilitating cacti growth

contrast exponential and logistic growth models, which is more realistic and why?

exponential - assumes density independence, no resource limit

logistic - assumes density dependence, limited resources

logistic is more realistic because it accounts for limiting resources and density, more realistic for plant pops (but neither account for difference in size/stage class!)

what are the seed traits that enable LDD in wind-dispersed seeds?

symmetric wings, larger seed wing area, smaller, lighter seeds, more of them, often in open habitats

tradeoffs of traits that allow LDD?

reduced nutrients for seeds when they germinate, not directional, energy costs of large seed production, more susceptible to predators?

2 main pools and fluxes in N cycle

pools = atmosphere, soil organic matter

fluxes = fossel fuel combustion, N fixation

T/F - the apical meristem is located in the leaf axils

F

T/F - carrying capacity in the real world is static and does not change

F

T/F - in even-aged populations plants have an average size, with no size hierarchy

F

T/F - each of the genetically identical tree stems making up Pando are individual genets

F

Adaptive plasticity has…

consequences for the fitness and genetic makeup of future generations

which describes the plant group that includes lichens/perennial herbs/shrubs/trees with long lifespan, small seed production, slow growth rate?

stress-tolerator strategy

major assumptions of the exponential growth model?

resources are not limited and poopulation growth is independent of populatioin density

in addition to average conditions, what is important when determining long-term rates of popoulation growth?

the variation of conditions over time

Lesser (2019) studied effects of deer browse, what did they find?

heavy deer browse can threaten forest ecosystems because it prevents tree regeneration and recruitment to canopy

retention time and turnover time are ___ related

inversely

the physiologically independent unit of a genet is called a ___

ramen

vegetative reproductive structure of a strawberry is called?

a stolon

results of Reich and Oleksyn (2008) suggest modest warming at northern latitudes will likely ____ growth and survival of scots pine

increase

an estimated list of vital rates (individual reproductive and survival abilities

life table

what are the three main macronutrients that plants require

nitrogen, phosphorous, potassium

blank is the mineral particle that gives soils the greatest external surface area, while _ is the mineral perticle that gives soils the least external surface area.

clay, sand

in arid areas, base saturation percentage is relatively ___ and concentrations of Al and H are relatively __

high, low

water moves through small pres and through films of water aroundsoil particles by capillary action

field capacity

sand vs clay porosity, permeability, water holding capacity, temperature changes

sand - low porosity, high permeability, low water holding capacity, high temperature change

clay - high porosity, low permeability, high water holding capacity, low temperature change