Chap 7- Tropical Forest Resources and Sustainable Development Flashcards
What are tropical forests?
Vegetation types including evergreen forests in tropical lowlands
How many tree species are found in Malaysia vs Nigeria?
Malaysia has about 2000 different tree species while Nigeria has about 560.
What is the difference between major and minor forest products?
This classification is subjective - a minor product in one place may be major in another. For example, gum arabic is a minor forest product in Nigeria but a major forest product elsewhere.
What are the latitude boundaries of tropical forests?
Tropical forests generally occur between latitude 24°S and 24°N, though boundaries aren’t rigid especially in Indo-China and Australia.
Name the four main tropical forest regions.
- African Tropical Forest Region 2. American Tropical Forest Region 3. Indo-Malaysian Tropical Forest Region 4. Australian Tropical Forest Region
What factors have reduced tropical forest areas in the last 50 years?
Forest clearing for agriculture, urbanization, road development, and improved exploitation technology.
What is the JARRI project and its significance?
It’s a multinational project in the Amazon that represents a massive assault on the tropical forest, demonstrating large-scale forest conversion.
What are the two prevailing winds that determine Nigeria’s seasons?
- North-East trade winds (cold, dust-laden, brings harmattan and dry season) 2. South-Westerly winds (moisture-laden, warm, brings rain and wet season)
What is the minimum annual rainfall required for rain forest in Southern Nigeria?
1400mm or more annual rainfall is required.
What are the three main tropical high forest types in Nigeria?
- Mangrove forest and coastal vegetation 2. Fresh water swamp forest 3. Lowland rain forest
What is the dominant tree species in mangrove forests?
Red mangrove (Rhizophora racemosa) whose bark is a source of tannin used in leather and plywood industries.
What percentage of Nigeria’s total land area does tropical high forest occupy?
Only about 2% of the total land area but accounts for more than 90% of the total timber supply.
What are the four forest storeys in tropical high forests?
Emergent, upper canopy, middle storey, and lower stratum trees
How tall can emergent trees grow?
They can grow over 50m tall with some species like Entandrophragma cylindricum reaching 59m with girths up to 17m.
What is the height range of upper canopy trees?
Trees in the upper canopy typically reach heights of over 30m.
What are the main uses of forest products in human economy?
Wood for timber, poles, panels, pulp for paper making, fuel, chemicals, and animals
What percentage of wood utilization in Tropical Africa is for fuelwood?
More than 90% of the total volume of wood utilized is for fuelwood.
What are the primary uses of fuelwood in rural communities?
Cooking, space warming, local brewing, baking industries, processing agricultural products, treating tobacco, smoking fish
Name two tree species found useful for pulp production in Nigeria.
Musanga ceropioides and Sterculia setigera were tested and found to possess long fiber.
What is the mean annual temperature range in tropical forests?
27°C to 30°C (mean annual temperature with small range)
What is the typical relative humidity in tropical forests?
Not below 70% in the morning and 60% in the afternoon
How does forest cover prevent soil erosion?
By converting rain drops to intercepted water and stem flow, which flows slowly along the soil surface
What is the role of forest cover in watershed management?
Prevents soil erosion, prevents siltation of dams, enhances water purity, reduces water treatment costs
How does forest cover maintain soil quality?
Improves water seepage, maintains water table, enhances soil organism activity, aids humus formation and soil aeration
What tree species are commonly used for shelter belts against desertification?
Eucalyptus species, Azadirachta indica, and Acacia species
What is agroforestry?
A practice where agriculture and silviculture are conducted side by side on the same piece of land without one necessarily quitting for the other.
Why did interest in farm forestry decline in temperate zones?
Following the demise of the small family farm, as trees, crops, and animals became separately managed at large scales
Why has agroforestry seen a resurgence in tropical regions?
Due to the failure of large agriculture and forestry monocultures in lesser developed world and concerns about tropical forest destruction
What are three key forms of agroforestry?
Agro-silviculture, silvo-pastoral, and agro-pastoral
What is the average annual rainfall in tropical forest regions?
Between 2000mm and 2500mm
How much timber did Nigeria produce in 1971?
About 2.8 million m³ of roundwood equivalent to sawn timber
What are examples of emergent tree species?
Lophira alata, Pitadeniastrum africanum, Khaya spp, Entandrophragma spp
What are examples of upper canopy tree species?
Holoptelea grandis, Triplochiton scleroxylon, Guarea cedrata, Khaya ivorensis
What is the height range of middle storey trees?
10-15m in height
What comprises the lower stratum of tropical forests?
Shrubs, young seedlings of big trees, and herbaceous plants
What are the main non-timber forest products (NTFP)?
Latex, rubber, essential oils, resins, gums, incense, spices, medicinal extracts, and tannins
How does forest litter help prevent soil erosion?
It prevents the carrying away of soil particles at the forest floor
What is the significance of breathing roots (pneumatophores)?
They enhance mangroves’ ability to reclaim coastal land forming chikoko soil
Name common tree species in fresh water swamp forests.
Mitragyna ciliata, Brachystegia spp, Raphia spp, Uapaca spp, Cleistaphois patens
What percentage of Nigeria’s timber came from South-Western high forests up to 1976?
Over 80% of timber for export and internal use
What are the primary uses of wood in rural industries?
Processing agricultural products, treating tobacco, smoking fish, bakeries, potteries
What is the width of the lowland rain forest belt in Nigeria?
About 250-300km wide from west to south-east
Why is the tropical forest considered a complex biological community?
It has an unparalleled diversity and interdependence of its component members especially flora and fauna
What environmental conditions make tropical forests unique?
High temperature, high rainfall, high humidity, and consistent soil moisture throughout the year
How do tropical forests contribute to water conservation?
By maintaining water table, preventing erosion, and ensuring water purity
What caused the 300% increase in forest conversion rate in the last 30-40 years?
Increasing demand for land cultivation, oil pipelines, and improved exploitation technology
