Marine Botany Exam 3

halophytes

plants that have adaptations to prevent

water loss and to grow in saline

habitats

mangrove (mangrove wetland)

Subtropical and tropical coastal

ecosystem dominated by halophytic

trees, shrubs, and other plants growing

in brackish to saline waters

Lenticle

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 tissues

coral reef

marine, biogenic, and wave-resistant

carbonate structures that are composed

of shells and skeletons of hermatypic

organisms

rhizosphere

narrow region of soil that is directly

influenced by root secretions and

associated soil microorganisms

Main limiting factor for mangrove

geographic distribution

temperature

List the 6 types of mangrove wetlands

(classifications)

coastal fringe, overwash islands,

riverine, basin, hammock, dward/scrub

What is the difference between prop

roots, drop roots, and pneumatophores?

prop roots - stem; drop roots - branches;

pneumatophores - verticle extensions of

horizontal roots

In addition to aerial roots, mangroves

also produce what 3 types of roots?

absorbing, anchoring, cable

3 adaptations mangrove leaves have

developed overtime to survive in

marine environments

Single layer epidermis, Thick outer

walls and cuticle, Specialized epidermal

cells, Hypodermis contains hydrocytes

or water containing cells

Salt marshes are found in areas where

the _____________ of sediments is

equal to or greater than the rate of land

subsidence and where there is adequate

protection from destructive waves and

storms

accumulation

How do abiotic stressors differ between

low and high marsh zones in salt

marshes?

low marsh more inundation; high marsh

salt content in soil

4 examples of salt content regulation in

marsh plants

Ion exclusion in roots, growth &

succulence, shedding, secretion (salt

glands), root discharge, controlling

water loss

3 types of xeric leaves found in salt

marsh plants

succulent, thick, dry type

3 commonly occurring salt marsh

genera in NC marshes

spartina/sporobolus, juncus, Salicornia,

Juncus, Arthrocnemum, Suaeda,

Plantago

What 5 characteristics define seagrass?

grow fully submerged; saline

environment; hydrophilious pollination;

roots; compete successfully in marine

environment

Only ___ % of 300,000+ angiosperms

live in the marine environment.

0.01%

Why are seagrass meristematic tissues

are especially vulnerable to low

oxygen

Located at transition between water

column and sediment, High metabolic

activity, High oxygen requirement for

mitotic growth

During the process of seagrass

evolution, angiosperms returned to the

sea how many years ago?

100 mya

3 seagrass species found in NC

Zostera marina, Halodule wrightii,

Ruppia maritima

List the two groups of organisms

primarily responsible for biogenic reef

building

Cnidarian corals, calcified red algae

Coral reefs develop in waters with

what 4 characteristics?

Oligotrophic water; High-water

transparency; High-water movement;

High stable water temp

What are the 4 primary biological

processes responsible for nutrient

uptake in coral reefs?

biofiltration by epiphytic microflora;

filter-feeding reef fauna; mutualistic

relationships; tight nutrient cycling

Why do corals dominate reefs in

tropical environments and algae

dominate in temperate environments?

nutrients/competition

Describe how coral polyps acquire

zooxanthellae

mobile stage; absorbed in digestive

track; protected by periplast; absorbed

into tissues

succulent

plant with fleshy tissues able to

conserve moisture

hydrophilous

Water mediated, abiotic pollination

vivipary

Germination of seedlings while the

fruit remains attached to the tree

salt marsh

a halophytic grassland on alluvial

sediments bordering saline water

bodies where water level fluctuates

either tidally or nontidally

hemicryptophyte

form of clonal growth where

perennating buds are situated at or just

below the soil surface

Mangrove flowers are perfect, meaning

they have what flowering organs?

sepals, petals, stamens, carpals

3 mangrove species found in US

Rhizophora (red), Avicennia (black),

Laguncularia (white)

What are the 4 adaptive characteristics

mangroves have developed to survive

in coastal systems?

attach to soft sediment

● Aerial roots

● Vivipary, seeds/seedlings survive/

disperse in saltwater

● Xerophytic an halophytic

modifications

General canopy characteristics of

mangrove forests

evergreen, ovate to elliptical leaves,

flexible but firm leathery leaves, salt

excreting glands

Mangrove seed dispersal is limited by

what 3 things

salt water, water movement, stressful

intertidal environment

How does high tide impact salt marsh

plants?

edaphic changes (lower soil aeration and

redox potential), lower photosynthesis,

damage or uprooting of plants due to

water movement, anaerobic sediments

5 major ecological roles of coastal

plant communities (including salt

marshes)

PP, Food source, habitat, sediment

stabilization, water filtration

3 xerophytic adaptations to maximize

water retention in stems, leaves, and

roots

increased lignification, complex

epidermal development, well-developed

bundle sheaths

Salt marsh ecosystems are balanced

between biota and what 2 other major

types of drivers?

hydrology & physiochemical

environment

3 ecophysiological impacts of salinity

stress on salt marsh plants

dehydration, increased cellular ionic

strength, loss of turgor pressure,

photosynthetic & metabolic shutdown,

curling, wilting, mortality

In a _________ seed bank, seeds

remain viable for < 1 year, while in a

persistent seed bank seeds are viable

for > 1 year

transient

What are the 3 main morphological

categories of seagrass plants?

Pair of petiolate leaves or two or more

leaflets; Shoots with a distinct erect

stem and strap-shaped leaves; Plants

without visible erect stems, but with

strap-shaped leaves

Patterns of reproduction will vary with

what 3 biotic factors?

genetics, physiology, conditions of the

local populations

Why are seagrasses called seagrasses?

herbaceous growth and formation of

extensive meadows

What are the 5 adaptation seagrasses

have developed to survive in the

marine environment?

hydrophyllic pollen, flexible tissues,

hydrodynamic design, no cuticle,

lacunar system

Direct or indirect human impact on

marine plants: Increased ultraviolet

irradiance

indirect

Direct or indirect human impact on

marine plants: dredging

direct

Halophytes have ________ growth

rates, _______ nutrient uptake rates,

and ______ photosynthesis compared

to non-halophytic plants

lower, lower, reduced

What are 3 advantages of asexual

reproduction?

maintains "good" genotypes; removes

need for opposite sex; escape in

numbers; removes real cost of

reproduction

Direct or indirect human impact on

marine plants: eutrophication

direct

How do seagrasses and algae differ?

Complex root structure to anchor plant

in the sediment, and extract nutrients

and minerals, photo in leaves, vascular

system, reproduce via flowers & seeds