week 5- mangrove habitats

Question 1

what is a mangrove

Answer 1

Tropical inshore communities dominated by species of trees and shrubs that grow in permanently salty water

Question 2

what type of plants grow in mangroves?

Answer 2

Mangrove species are terrestrial plants that have colonized the fringes of the sea

Question 3

what do man groves buffer

Answer 3

Mangroves buffer tropical shorelines from erosion and filter runoff

Question 4

where are mangroves found

Answer 4

in the tropics

Question 5

what are the mangrove roots like and what is the soil like?

Answer 5

Mangrove roots grow in a hostile soil environment
Soil is oxygen deficient and often has a higher salinity than open ocean due to evaporation

Question 6

what is an anoxic soil?

Answer 6

In the absence of oxygen, anoxic reactions take place sequentially as organic material is broken down

Question 7

what are the root adaptations for anoxic soils?

Answer 7

• Shallow rooting system that is wide-spread or perpendicular to the trunk
• Elongation in Rhizophora can be as much as 9 mm a day
• There are several species-specific adaptations to cope with the oxygen-deficient soil
• Most of these consist of aerial roots that can represent up to 24% of above ground biomass

Question 8

Mangrove root adaptations

Answer 8

Aerial roots of Rhizophora are often known as stilt roots
Branching increases anchorage points also securing the plant against wave action
The height of pneumatophores is a response to tidal cycles of water submergance

Question 9

Root adaptations for saline soils

Answer 9

• To counteract the uptake of salt water, root systems build negative hydrostatic pressure by transpiring salts at the leaves through salt glands
• Leaves have hairs to precipitate the droplets of salty water