Scenario 7 + 8 Flashcards
What are crustaceans in the class thecostraca?
barnacles
Define tides and explain how they work. Differentiate between spring and neap tides.
- Tides are the rise and fall of sea levels caused by the gravitational forces exerted by the Moon and the Sun, as well as the rotation of the Earth
- Spring Tides: when the Sun, Moon, and Earth are aligned in a straight line. During spring tides, the gravitational forces of the Sun and the Moon reinforce each other, leading to higher high tides and lower low tides.
- Neap Tides: when the Sun, Moon, and Earth form a right angle- gravitational forces of the Sun and the Moon partially cancel each other out
Describe Vertical Zonation, and how it shapes the biological communities on the Rocky Shore, why does vertical zonation exist?
- exists primarily due to the gradient of environmental conditions along the rocky shore- eg: wave energy, exposure to air + sun, moisture levels, and temperature
- also competition + predation
Explain how the major zones differ from one another (abiotic and biotic stressors)
- Splash Zone: above the highest high tide mark, only intermittently wet- organisms must tolerate extreme fluctuations in temp, moisture, + sun
- High Intertidal Zone: This zone is submerged during high tide but exposed to air during low tide-periwinkles, limpets, seaweed.
- Mid Intertidal Zone: This zone is submerged for longer periods- less extreme conditions: barnacles, mussels, sea stars
- Low Intertidal Zone: submerged most of the time except during very low tides: kelp forests, anemones, and sea urchins
Compare and contrast biological vs abiotic stressors in the rocky intertidal
biotic: competition, predation, herbivory/grazing, parasitism/disease
abiotic: waves, temp, sun, salinity, moisture (dessication),
Understand the various adaptations to abiotic stressors in the rocky intertidal, and be able to provide examples of each.
waves: attachment(byssal threads), flattened structure
temp: snails hide under rocks, mussels have protective heat proteins
salinity: osmoregulation
dessication: mucus coatings, shell closure
sun: “sunscreen” pigments (eg: algae), thick cuticle in plants + algae
salt marshes
- coastal wetlands flooded and drained by saltwater tides
- found in temperate and subtropical regions
- feature halophytic plants adapted to saline conditions
- provide habitat for diverse wildlife -ecosystem services: coastal protection, water filtration, carbon sequestration
Describe the anatomical and biological features of salt marsh cordgrass that allow it to survive saline and anoxic sediments.
- aerenchyma: air-filled spaces in its stems and roots, facilitating oxygen transport to submerged tissues
- salt-secreting gland system: excretes excess salt, crucial for osmoregulation in saline conditions
- rhizomes: underground stems, allow for vegetative reproduction and the spread of the plant, aiding in stabilizing sediments and expanding marsh habitat
What is blue carbon? What are the driving factors behind salt marsh capacity for sequestration and storage of large amounts of carbon?
- C stored + sequestered in marine envis
- Salt marshes sequester carbon dioxide through the growth and accumulation of plant biomass and the burial of organic carbon in their sediments (dead plant material)
Describe the mutualistic relationships between smooth cordgrass and ribbed mussels, and smooth cordgrass and fiddler crabs.
- mussels: grass provides habitat + protection, mussels stabilize sediment + cycle nutrients by filtering water + depositing organic matter
- fiddler crabs burrow + aerate soil
Describe the process of marsh colonization and development and how asexual and/or sexual reproduction of smooth cordgrass plays a role.
- begins with pioneer plants like smooth cordgrass that trap sediments, creating stable ground for further colonization by other marsh species
- Sexual reproduction of cordgrass involves the fertilization of seeds through pollination
- Asexual repro of cordgrass: rhizomes
Describe wrack, and how it plays a role in the introduction of genetic diversity into salt marsh meadows.
- dead plant material
- transporting seeds and propagules from distant locations- introduces new genetic variants to the marsh, enhancing adaptability and resilience to environmental changes.
