Mangrove Biology Worksheet

Name
Date
Mangrove Biology
Read the background information below independently or in small groups.
Mangrove trees are a very important part of estuary ecosystems. They filter water by removing
toxins and stabilize silt that enters into estuaries from rivers and coastal runoff. They provide
habitat and nursery grounds for many species of vertebrates and invertebrates. The trees absorb
wave energy and prevent erosion. Their leaves are a food source for many organisms. They also
build new land from the accumulation of fallen decomposed leaves.
Oil that infiltrates mangrove ecosystems by washing into mudflats during high tides is a major
threat to the health of mangrove forests. Oil can clog the pores on the snorkel roots of black
mangrove trees, causing them to suffocate and die.
Mangrove trees are tropical/subtropical plants. There are three different species of mangrove
trees that live on the shorelines and in the estuaries of Mississippi, Alabama, Louisiana, and
Florida: red, black, and white mangrove trees. These trees have specific niches that they occupy.
Red mangroves grow in the water and directly on the shoreline. Black mangrove trees grow in the
mudflats set back from the water. White mangrove trees grow the farthest away from the water
on dry land that is occasionally flooded by salt water.
Black and white mangrove trees have a different strategy for living in a salty environment. They
are salt excreters. Black mangroves live in anoxic mudflats that are often flooded by the tides.
When salt enters through the roots of the tree, it is then filtered up the trunk and out through
pores onto its leaves. The salt is then eliminated from the tree’s system and the leaves are coated
with salt, providing the leaves with a natural sunscreen.
Due to the lack of air in the sediment, black mangroves have specialized snorkel roots called
pneumatophores to help them breathe. Each black mangrove tree sends up hundreds of
pneumatophores from its root system. Each snorkel root has special pores called lenticels.
These pores enable the mangrove to get the air that it needs to thrive in an otherwise airless
environment.
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These trees have evolved specialized strategies to survive in salty environments. Red mangrove
trees are salt excluders. They have specialized roots that prop them out of the salt water. They
keep salt out of their systems through root filtration. Red mangroves can live submerged in
salt water due to their ability to exclude salt. Any salt that does get into the system of this tree
species is sent to sacrificial leaves. When these leaves are full of salt they are dropped from the
tree, eliminating the salt from tree’s system.
Name
Date
Mangrove Biology, continued
Mangrove Vocabulary
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Word(s)
Part of Speech
Definition
anoxic
adjective
no oxygen in the environment
drop roots
noun
roots that drop down from the branches of red mangrove
trees and set shoots into the ground
ecology
noun
the study of the environment and its related communities
Eqios= the home, ology= the study of (the study of the
home)
lenticel
noun
a small opening on the exposed roots of a tree that allows
the plant to take in air to send to the rest of the root system
pneumatophore
noun
the snorkel root of a tree
prop roots
noun
roots of the red mangrove that keep the trunk of the
mangrove out of salt water
salt excluder
noun
an organism that will not let salt enter into itself
salt excreter
noun
when an organism pushes salt out through its pores
sediment
noun
underwater soil
substrate
noun
underlayer; something to hold on to or attach to
Oil Spill Cleanup Vocabulary
Word(s)
Part of Speech
Definition
boom
noun
A boom is an oil-containment device that floats on the
surface of the water and is used as a barrier to keep oil in or
out of a specific location.
dispersants
noun
Dispersants are chemicals that are sprayed on oil to cause it
to break up and sink.
skimmers
noun
Skimmers use a floating boom system to sweep oil across
the water surface, concentrating the oil to make the
skimming process more effective and efficient.
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© 2010 National Geographic Society
e