Natural vegetation: Mangroves
Location in Singapore: Sungei Buloh Wetland Reserve
Introduction
Mangroves are considered one of the most tenacious natural vegetation in the world.
Mangroves are trees that grow in saline coastal habitats in the tropical and sub-tropical regions.
The benefits of mangroves are endless.
The benefits of mangroves are endless.
Mangroves protect coastal areas from ersosion, storm surge and tsunamis. Hence, it is important for us to preserve the mangrove ecosystem and not destroy them for selfish purposes such as the construction of steelmills and ports.
They also host several species of fish and crustaceans that are "commercially important" as well as the main source of income for many fishermen in some countries.
As a result of their wide range of benefits, they are often the object of conservation programs, including national Biodiversity Action Plans.
- A styrofoam box caught in the stilt roots of a mangrove.
We should not litter in nature reserves or in rivers as litter will be caught in the roots of mangroves after high tides. We must all do our part to keep our homeland clean for future generations to see and appreciate.
Characteristics and adaptations of Mangroves:
Red mangroves' seeds germinate while still on the parent plant.
The seeds are also buoyant and thus, suitable for water dispersal. This is how mangroves adapt to their coastal surroundings. Furthermore, some mangroves' seedlings form propagules which can produce its own food via photosynthesis. Once mature, the propagules drop into the water which can be transported for long distances. To further increase the chances of survival in such harsh conditions, propagules can survive desiccation and remain dormant for months before arriving in a suitable environment.
- Red mangroves' seeds
- A mangrove's bud and a dying propagule
- Red mangroves' seeds
- A mangrove's bud and a dying propagule
- Some young mangroves
2. Limiting water loss:
Due to the limited supply of freshwater, mangroves have found ways to limit their loss of water through transpiration.
This includes waxy leaves, restricting the opening of their stomata, and even vary the the orientation of their leaves away from the scorching midday sun, thus reducing the rate of evaporation from the leaves.
- Waxy leaves and different orientations of leaves
3. Adaptations to salt water:
Mangroves grow in saline conditions. Many vegetation are not able to grow in salty waters. How do mangroves adapt to it? Mangroves adapt to salt water by limiting the intake of salt.
These are some of the methods:
Red mangroves excrete salt through their roots or concentrate salt in old leaves which are then shed. They can also store salt in cell vacuoles.
Red mangroves excrete salt through their roots or concentrate salt in old leaves which are then shed. They can also store salt in cell vacuoles.
White/Grey mangroves are able to secrete salts directly as they have salt glands at each leaf base. Thus, it is common to see salt crystals on the surface of their leaves.
- Leaf with tiny salt crystals (white spots)
- Dying leaves
4. Adaptations to low oxygen:
Red mangroves have prop/stilt roots that prop themselves up above the water level and then absorb air through pores in their bark.
Black mangroves live on higher grounds, thus having no need for prop roots. They produce pneumatophores, that are covered with lenticels, which stick up through the surface of the soil in order to take in oxygen.
- Black mangroves' "breathing tubes"
- Knee-like pneumatophores
- Stilt roots/Prop roots
Bibliography
One other natural vegetation: Tropical rainforest
Introduction
Distribution of rainforests: Tropical rainforests are found within 10 degrees south or north of the Equator. They can be found in places such as: Asia, Australia, Africa, South America and Central America.
Rainforests are also home to half of all the living animal and plant species in the planet. They are considered to be the world's "largest pharmacy" as over 25% of modern medicines originate from their plants.
Due to rapid deforestation for unreasonable and selfish reasons, tropical rainforests are now considered to be "endangered". We can all do our part by reusing and recycling paper as well as reducing the usage of paper and by supporting the Green Movement.
Annual rainfall: 1750ml - 2000ml.
Mean monthly temperatures: Above 18 degrees C for the whole year.
Characteristics of Tropical Rainforests:
Group photo taken at the Sungei Buloh sign. Song Lin was holding the camera.
Group Members: Song Lin, Boon Wei, Jonathan and Jian Cong.
No comments:
Post a Comment