a.
i. Selective exploitation in forest management refers to the practice of harvesting only a portion of the mature trees in a forest, while leaving the rest to continue growing and contributing to the ecosystem. This approach aims to maintain the overall health and productivity of the forest while also providing economic benefits through timber harvesting.
ii. Some advantages of selective exploitation of forest trees include:
- Sustainable management: Selective exploitation helps to ensure that forests are managed in a sustainable manner, as only a portion of the mature trees are harvested, leaving the rest to continue growing and contributing to the ecosystem.
- Biodiversity conservation: Selective exploitation can help to conserve biodiversity by leaving habitat for wildlife and preserving a variety of tree species and other plants in the forest.
- Economic benefits: Selective exploitation provides economic benefits through timber harvesting, while also maintaining the overall health and productivity of the forest.
- Carbon sequestration: Forests play an important role in carbon sequestration, and selective exploitation can help to maintain this function by preserving mature trees that continue to store carbon.
b. Field pests are insects and other organisms that attack crops while they are growing in the field. Examples of field pests include aphids, caterpillars, and grasshoppers. Storage pests, on the other hand, are insects and other organisms that attack crops after they have been harvested and stored. Examples of storage pests include weevils, moths, and beetles.
c.
i. Examples of storage insect pests of crops include the maize weevil, rice weevil, and bean beetle. These insects can infest stored crops such as grains, beans, and nuts, causing damage and reducing the quality of the harvested crops.
ii. Examples of field insect pests of crops include aphids, which can infest and damage a variety of crops including fruits, vegetables, and grains; armyworms, which can cause extensive damage to corn and other crops; and Colorado potato beetles, which can damage potato plants.
d. Ways of conserving water in the soil include:
- Mulching: Mulching involves covering the soil with a layer of organic material such as leaves, straw, or wood chips. This helps to reduce water evaporation from the soil, keeping it moist for longer periods of time.
- Irrigation management: Proper irrigation management can help to conserve water in the soil by reducing water loss through runoff or deep percolation. This can be achieved through techniques such as drip irrigation, which delivers water directly to the roots of plants, or by using water-efficient irrigation systems.
- Soil management: Managing the soil can also help to conserve water. Techniques such as adding organic matter to the soil can improve its water-holding capacity, while reducing tillage can help to minimize soil disturbance and water loss through evaporation.
- Crop selection: Choosing crops that are adapted to the local climate and soil conditions can help to conserve water, as these crops will require less irrigation and can better tolerate dry conditions.