Page 244 - (DK) Ocean - The Definitive Visual Guide

242 PLANT LIFE

Plant Life HUMAN IMPACT
BEACH PLANTS

PLANTS FORM A GREAT kingdom of life-forms, Beach plants grow in places used
DOMAIN Eucarya by humans for recreation. We can
all of which use the pigment chlorophyll to coexist, especially when people
KINGDOM Plantae
fix carbon dioxide from the atmosphere into use paths in coastal dune areas. In
SPECIES 315,000 fact, paths maintain low-growing
organic molecules, using energy from sunlight. plants, such as mosses, which
Most organisms in the plant kingdom are “higher” plants, which might otherwise become
overgrown. However, fragile dunes
evolved on land and remain land-based. Of these, several unrelated are damaged by erosion, and plants
families of flowering plants (see p.250) have since returned to the sea that grow only in a limited strip
of coastal habitat are highly
or taken up residence on the coast. The plant kingdom, as defined in vulnerable to human development.
this book, also encompasses more primitive organisms that first SAND CROCUS
The sand crocus of the Canary Islands grows
evolved in water—the microscopic green algae (microalgae) and only in a few coastal locations on Lanzarote
the green and red seaweeds (macroalgae). Brown seaweeds appear and Fuerteventura. It is protected, but
threatened by tourism development.
very similar but may not be closely related to true plants and are
classified in this book in the phylum Chromista (see p.236).

Marine Plant Diversity TROPICAL MARINE PLANTS
Seagrasses are abundant in
Plants are united by their use of chlorophyll for photosynthesis. tropical lagoons, and green
seaweeds include calcified
The higher plants include several major land-based groups,
species. Mangroves line
including ferns and conifers. Because higher plants evolved estuaries and creeks, and
on land, they are adapted to life in air and to fresh water. other flowering plants,
They have tissues bearing vessels that transport water and food. including shrubs and trees,
Of the higher plants, it is mainly the flowering plants (the colonize the back of sandy
beaches. Although not shown
largest group) that have invaded marine habitats. Along with
here, seaweeds may grow
mosses, they inhabit the coastal fringes, with only the seagrasses seasonally on rocky shores. BEACH
being fully marine. Green seaweeds and microscopic green
algae (microalgae) lack stems and roots, have neither woody coconut palm
tissues nor transport vessels, and are mostly aquatic. MANGROVE SWAMP
TEMPERATE MARINE PLANTS mangrove
Temperate seas are rich in phytoplankton, tree high tide mark
including green algae. Green algae
commonly grow on rocks and intertidal zone of beach
red algae on mud flats. mermaid’s wine glass
Seagrasses have true roots SEA CLIFF sea campion alga, Acetabularia
and live in sediment in the Halophila sea grass
shallow subtidal and intertidal clear water with
zones, and in brackish lagoons. few algae
Above high water, cliffs, sand
dunes, and salt marshes
are home to flowering
plants, mosses and lichens.
DUNES
dune flower moss
marram
grass SHORE
red seaweeds on
thrift intertidal rocks Caulerpa
seaweed
green seaweeds LAGOON
SALT MARSH on intertidal rocks
sea lettuce seaweed
on boulders and
bedrock CORAL REEF
red seaweeds in
subtidal zone
Codium seaweed
on boulders and
brackish bedrock
lagoon SEA ROCKET
OCEAN LIFE sea rocket above eelgrass in sediment SEMI-SHELTERED EXPOSED of the brassica family,
Ulva seaweed
A European member
in channel
sea rocket can grow
SHORE
high tide
on pure sand, just above
intertidal zone
high tide, where it traps
sand, forming small foredunes.
SHORE
in subtidal zone
while its stubby fruit pods are
surface water thick
SHELTERED Its waxy leaves repel sea spray,
dispersed by the tide.
with green microalgae
SHORE