| Equatorial
ecosystems
By
Marjorie Henry, Contributor
 |
| Students
gather at Sangster's Book Store's booth in April, on day two of the Gleaner Company's
'Youthlink' CXC seminar in Montego Bay, St. James. - Photo by Claudine Housen/Staff
Photographer | In
the lesson last week, I started to discuss the equatorial ecosystems. The location
of the equatorial climate and the major characteristics of it were mentioned.
Here are a few questions to review that lesson: 1
Within what latitudes is the equatorial climate found? 2.
Where in South America can an example of this climatic type be found? 3.
State the average monthly temperature of this climate. 4.
What is the dominant factor about the temperature here? 5.
Give the approximate amount of rainfall received and state when it occurs. 6.
What is the main type of rainfall that occurs? 7.
When does (1) most rainfall occur and the (11) least rainfall occur?  | | SOURCES:
'General Geography in Diagrams' by R. B. Bunnett.
'The Caribbean Environment
for CXC Geography' by Mark Wilson. | The
rainforest ecosystem |
Today,
I share with you the characteristics of the vegetation of the equatorial climate
as promised. This is directly linked to the climate of this region. The very heavy
rainfall and uniformly-high temperature support a luxuriant type of dense vegetation
known as the tropical rainforest. A
great variety of different species of trees is found in this region. Some of the
valuable trees are rosewood, mahogany, ebony, greenheart and rubber. The trees
which are mainly hardwoods, have an evergreen appearance, for although they are
deciduous, they shed their leaves at any time during the continuous growing season.
A continuous
plant growth throughout the year is possible since the growing season in equatorial
regions is not restricted by either drought or cold. In
addition to the trees already listed, there are smaller palm trees, climbing plants,
such as lianas or rattan, which may be hundreds of metres long, and epiphytic
and parasitic plants that live on other plants. Under
the trees grow a wide variety of creepers, ferns, orchids and lalang. The
tropical rainforest is characterised by a distinct layer arrangement. Top
layer: tall trees with buttress roots. Middle
layer: tree ferns, lianas and epiphytes, for example, orchids. Bottom
Layer: ferns, herbaceous plants and saprophytes. This
layer arrangement is presented in the sketch above and shows how the different
components within the equatorial ecosystem relate to each other. This
lesson cannot possibly give you all the information on the topic, so again I am
directing you to the available textbooks to source the additional information.
Marjorie
Henry teaches at Glenmiur High School. | 
