(a) Explain the term, conservation of natural resources.
(b)(i) List seven methods of soil conservation.
(ii) Name four other natural resources that may be conserved.
(c) State three factors which negatively affect conservation of forest in West Africa.
(d) Describe what happens during the denitrification stage of the nitrogen cycle.
Explanation
(a) Conservation of natural resources is necessary for the following reasons:
(1) The wise use/safe-keeping/ management of natural resources, for the benefit of mankind, (2) To ensure their continuous availability/avoid their decline/extinction.
(b)(i) The following are the methods of soil conservation:
(1) Planting grasses/legumes
(2) Crops must be planted on ridges across slopes
(3) Practicing shifting cultivation/bush fallowing/crop rotation
(4) Avoiding/preventing bush burning
(5) Addition of manure/fertilizer to the top soil
(6) Spreading a layer of vegetable material on cultivated farmland/mulching
(7) Constructing ridges across the slope of the land at intervals/contour ridging
(8) Planting trees/reafforestation
(9) Prevention of over-grazing
(ii) Natural resources that can be conserved are:
(1) Water
(2) Forest
(3) Wildlife
(4) Mineral resources
(5) Genetic mineral/genes
(6) Petroleum/coal/gas/fossil fuel/ iron ore, tin, gold
(c) Factors that negatively affect conservation of forest in West Africa include the following:
(1) Uncontrolled/over-exploitation of forest trees/indiscriminate felling/lumbering of forest trees
(2) Lack of afforestation/tree planting.
(3)Bush burning/wild fires
(4) Non enforcement of conservation laws
(5) Lack of /no knowledge of conservation education/awareness
(6) Use of firewood/charcoal for fuel
(7) Air/soil pollution.
(d) Denitrification stage of the nitrogen cycle: -
- Denitrifying bacteria/certain fungi in the soil
- Convert nitrates into nitrites
- Some bacteria/pseudomonas spp can convert ammonia/nitrite/nitrate into gaseous nitrogen, which is released into the atmosphere, leading to reduction of soil nitrogen content, resulting in reduced soil fertility