Marine Botany Final

Marine botany

scientific study of saline adapted plants in their natural habitat

Photosynthetically active Radiation (PAR)

solar radiation between 400-700 nanometers that can be used by plants for photosynthesis

Boundary layer

slow moving water around plants that’s thickness can determine the plant’s ability to uptake nutrients

Fundamental niche

the full abiotic and biotic extent an organism can live, influence the environment, and perform necessary functions. The fundamental niche does not consider bioitc conditions like competition that would limit the species’ range

Estuaries can be divided into what 4 geologic origins?

Fjords, bar built, tectonic, flooded river plain

Describe two adaptations marine plants use to cope with wave energy

Marine plants can develop thick rhizomes and thin bladed leaves. Adaptations seen in phyllospadix; thick rhizomes help the plant stay anchored in the rocky substrate against harsh energy and thin blades help prevent drag from heavy waves that would uproot the plant

Halophyte

A plant adapted to grow in high salinity conditions

Ocean water contains 12 conservative elements. List one element besides sodium (Na) and chloride (Cl)

Bicarbonate

Marine plants include organisms that are grouped as angiosperms, protists, and bacteria. Give an example for each grouping

bacteria- cyanobacteria

protist- algae

angiosperm- mangrove tree

Explain the difference between vicariance and dispersal hypotheses for seagrass and mangrove distribution

In the coral triangle, seagrass underwent variation through the dispersal hypothesis- they diversified and speciated from an already establish barrier and developed into new species over time.

Some mangroves around the world are genetically similar. This is explained by the vicariance hypothesis- tectonic plate movement and distribution of land masses from pangea caused a large fragmentation of these habitats. A barrier later established caused speciation.

Explain why in the graph below net photosynthesis was low during a period of maximum gross photosynthesis

Maximum photosynthesis is influenced by light availability. Maximum respiration is influenced by temperature. Net photosynthesis was low during maximum gross photosynthesis of high temperature that caused respiration rates to spike. Because net photosynthesis is gross photosynthesis minus respiratory losses, net photosynthesis is limited by respiration and gross photosynthesis.

What is the name of the “sea” found in the North Atlantic bordered only by ocean currents? What is the dominant marine plant found in this area and why is this region important for oceanic organisms?

Sargasso sea- sargassum found in the area and important as a biodiversity hotspot

Describe what a dichotomous key is, and why it is an important tool for Marine Botany

identification tool used to ID organisms to species asking 2 questions at a time on characteristics. serves to ID in field inform conservation, restoration, and research.

Explain the differences between biomass and productivity

biomass- amount of organic weight of a population or community per specified area

productivity- amount of carbon absorbed per specified time

Sandy coastlines develop along areas with these three characteristics

gentle continental plate slopes, depositionally dominated areas, areas of passive margin plates

List and describe two of the four strategies marine plants use to deal with changes in salinity

salt secreting glands- mangroves actively exclude salt through these glands onto leaves and store salt in tissues. Also control salt excretion rate to conserve energy

osmoregulation through epidermal cells- seagrasses can balance ion concentrations through their epidermal cells to keep water balance

Explain how tides and waves affect seagrass colonization depth

Low tidal ranges can encourage extensive colonization range. Big tidal ranges limit seagrass shallow colonization because of exposure to dessication; deep colonizations limited by light attenuation. Low wave energy can encourage extensive colonization range. High wave energy limits shallow colonization depth due to increased turbidity of suspended solids.

Oceanic production is nutrient limited. Other than nitrogen and phosphorus, what is one other major limited nutrient in the ocean?

Iron

Draw P-I curves for shade tolerant and sun tolerant plants (2 seperate lines). Compare photosynthetic efficiency, saturating irradiance (lk), compensation point (lpc), and level of photoinhibition.

photosynthesis on y. Light level on x. shade tolerant lower saturation point and inhibition, higher rate of photosynthesis than sun tolerant before saturation. compensation light is light level where photosynthesis is more than respiration

Why are intermidiate water flow velocities considered optimal for seagrass growth?

Intermediate water flow is optimal for seagrass because it is slow enough where it doesn’t cause shelf shading, soil and plant erosion, or low soil nutrients, and it is fast enough where it doesn’t cause a large boundary layer to form or allow organic build up.

How do quantitative and qualitative descriptons in dichoteomous keys differ

Quantitative descriptions are about numbers, such as “This plant is ~6m tall” or “This plant has 4 leaves”. Qualitative descriptions are physical descriptions not involving numbers such as “this plant is green” or “this plant has roots”

What are three sediment characteristics that affect marine plants

soil size (silt, sand, clay), redox potential, and organic content

List 4 parts of a light microscope

base, appetures, light, and lenses

Algae

photosynthetic organism nonvascular, that contains chlorophyll, does not have try leaves, roots, or stems. dont have protective gametic cells

Conceptacles

located in receptacles. hold sexual structures for reproduction

Dioecious

have a distinct and seperate male and female organisms. One plant can’t have both sexual parts

Rhodoliths

rounded nodules of coralline red algae that develops around the surface of stones. Provides transition zones between rocky and sandy habitats

Phaeophyta matching characteristics

main pigment is fucoxanthin

produces physodes for herbivore resistance

flagella emerge laterally rather than apically

high biomass production; includes kelps

pheromone signaling important for reproduction

Rhodophyta matching characteristics

Possess pit plugs

can photosynthesize at depths >200m

common genera include gracilaria

Chlorophyta matching characteristics

likely ancestors of land plants

marine forms mainly in prasionophyceae and ulvophyceae

List two ecological services macroalgae provide

cycle nutrients and provide coastal protection through stabalization

Which macroalgal construction type (filamentous, foliose, tubular, or multiaxial/parenchymatous) is most likely to provide the greatest mechanical strength against waves and why?

parenchymatous because of its 3D growth providing enforcement and flexibility agaisnt waves. Parenchymatous growth also allows specialized holdfasts for anchoring

How do holdfasts differ from true roots

don’t absorb nutrients or water

compare apical, parenchymatous, and intercalary growth in algae

apical growth is from top (or apical) cells of algae

parenchymatous is 3D growth and is not restricted to any cell

intercalary growth is in a defined area not occuring at apical cells

Describe one way algae is used as a research tool

used as a bioassay- responds to environmental stressors before other organisms, so their response is telling of physical and chemical conditions of the environment

Explain the ecological importance of giant kelps (laminariales) and how their growth form supports coastal ecosystems

influence water flow which in turn influences larvae dispersal, hold sediment, cycle nutrients, and provide habitat. their parenchymatous growth form is important for supporting larvae dispersal and providing complex habitats.

compare and contrast zygotic meiosis, gametic meiosis, and sporic meiosis (alternation of generations) include what stage is dominant and when meiosis occurs

zygotic meiosis has a haploid vegetative dominate stage and meiosis occurs at the formation of the zygote (diploid)

gametic meiosis has a diploid dominant vegetatie stage and meiosis occurs to form gametes (haploid)

sporic meiosis has both a diploid (gametphyte) and haploid (sporophyte) dominant multicellular stage. meiosis occurs upon formation of spres. Mitosis is used for gamete production

describe two unique traits of rhodophyta sexual reproduction that distinguish them from other macroalgae

have triphasic alternation of generation stage and relies on the formation of tetrasporophytes

list and describe the three main stages of holdfasts

discus- organic mucus to hold algae

hapterous- claw like to attach to structure

rhizoid- rhizome (root w multiple shoots) like stucture

name and briefly describe two bioactive compounds from macroalgae that have pharmaceutical or nutraceutical importance

polyphenols such as phlorotannins, and pigments such as caretenoids have pharmaceutical and nutraceutical importance such as antioxidant, antimicrobials- decreased heart and cancer risks.

describe how coralline red algae contribute to coral reef stability

coralline red algae is a keystone species that uses its flat thallus structure and mucus like holdfast to stabalize coral reefs

list three commercial or household products that contain algae

fruit gushers, beer, and toothpaste

what are 3 of 5 common characteristics that all chlorophyta algae share

stores starch in chloroplast

contain 3-5 thylakoids

double membrane chlorplast

What is ocean afforestation and what is one potential benefit or risk

ocean afforestation is growing kelp and sinking it to the deep ocean to sequester carbon. A potential risk is unkown impacts on bethos. A benefic is potential long term sequestration of carbon

most brown algal species are found along coasts with cold temperature to polar climates. what adaptation have brown algae developed to withstand these extremely cold temperatures

sulfated polysaccharides, alginates, and photosynthetic byproducts such as glycerin

Salt marsh

a halophytic grassland in alluvial soils in estuarine waters that experiences changes in water level tidally or nontidally

coral reef

a biogenic structure composed of shells and carbonate produced by hermatypic organisms. very diverse and foundin tropical, high light, low nutrient, stable high water temps, and constantly moving waters

lenticles

a loose aggregation of cells which penetrates the surface (as of a stem) of a woody plant and through which gases are exchanged between the atmosphere and the underlying tissue

Rhizosphere

the area around the rhizome and associated organisms. created from gas exchange between rhizomial roots and surrounding soil

vivipary

when the fruit germinates while still attached to the tree. adaptation deals with the saline, tidally influenced waters

salt marshes are found in areas where the ___ of sediments is equal to or ___ than the rate of land subsidence and where there is adequate protection from destructive waves and storms

accretion; greater

emergent marine plant communities shift from ____ dominance to ____ dominance as temperatures move from tropical to temperate conditions

mangrove; salt marsh

the two groups of organisms primarily responsible for biogeneic reef building include

cnidarian corals and calcified red algae

halophytes have ___ growth rates, lower nutrient uptake rates, and ___ photosynthesis compared to non-halophytic plants (making them less competitive when salinity is not stressful)

lower, lower rates of

mangroves have _____ flowers, meaning them contain sepals, petals, stamens, and carpals

perfect

the loss of federal protection under sackett v EPA reduces conservation of isolated or intermittenly connected ___

wetlands

blue carbon systems including _____, mangroves, and salt marshes, are major global carbon sinks

seagrass meadows

List and describe 3 of the 6 types of mangroves

overwash island- an island that is regularly inundated. organic material is washed out regularly and this island substory is dominated by pneumatophore prop roots

dwarf/scrub- this mangal is characteriszed by short mangroves (<2m), very saline soil conditions, and lime stone/sandy soils. this mangrove is less productive than other mangroves

hammock- mangal is characterized by its peat deposition allowing it to sit 5-10cm above surrounding land. this magrove island is constantly flooded and there is typically a hypersaline pool in the middle with smaller mangroves

why are anaerobic soils a big problem for marine plants? describe the adaptations that marine plants have developed to help offset the stressors related to anerobic soils

slows down diffusion of gases. in salt marsh plants, the restricted diffusion of oxygen can cause toxic buildup of sulfides and mtals. lacunae and arenchyma are an adaptation to offset stressors from anerobic soils. These are vein like, air filled structures that facilitate gas exchange. aerial roots are another adaptation- these roots take gas directly from the atmosphere as they are above ground. They can also photosythesize

List 4 adaptive characteristics mangroves have developed to survive in coastal systems

vivipary, roots to adapt to unstable soils, aerial roots for gas exchange, xeric and halophytic anotomical adaptations

coral reefs develop in waters with what 4 characteristics

oligatrophic/low nutrients

low turbidity/above 10% irradiance transmittance

hot and stable water temps

constantly moving water

what defines seagrasses (5 things)

hydrophyllous pollen

reliance on anchoring true roots

adapted to live in a saline medium

can compete in a marine environment

can live and grow in fully submerged saline waters

Regulation of salt marsh shoot content is accomplished through a variety of mechanisms/ List 4 examples of salt content regulation in marsh plants

leaf shedding

active exclusion in roots

leaf excretion

succulence

What are the 4 primary biological processes responsible for nutrient uptake in coral reefs

biofiltration from epiphytes

filter feeding fauna

symbiotic relationship nutrient cycling

tight nutrient cycling in a semi-closed environment

how do abiotic stressors differ from low and high marsh zones in salt marshes

low marsh stressors are caused by inundation while high marsh stressors are caused by high salinities

what are 3 adaptations seagrasses have developed to survive in the marine environment

hyrophyllous pollen

no/little cuticle/ no stomata

flexibility/little lignin

list and describe the three types of xeric leaves found in salt marsh plants

dry- dry type leaves have special physiological adaptations to curl up to reduce water loss

succulent- petioles wrap around stem, replacing leaves as photosynthetic organ and swells with water to dilute ion concentration and stay hydrated

thick- have increased photosynthetic and xeric tissues to help with salt stress

describe how nutrient cycling supports high productivity in coral reefs. in answer, explain how cycling of nitrogen and phosphorus differ within in these systems

supports high productivity through photosynthetic coupling. Corals can use processes such as calcification to assist photosyntehsis through byproducts. Photosynthesis can then contribute to production of CaCO3 through carbon fixation. Reefs have tight cycling and photosytnesis to respiration rates are close to 1. biofltering flora and fauna along with symbiotic relationships support high productivity in reefs to support higher trophic levels. coral reefs support all stages of the N cycle including fixation through cyanobacteria. Corals can be exporters of nitrogen to other ecosystems. Phosphorous in DIP is less prevelant. Coral reefs are not exporters of phosphorus.

what are three of the major ecological roles of coastal plant communities

provide food, filter water, and provide coastal protection services such as surge protection and erosion control