OBJECTIVE FORESTRY

Detailed explanation-1: -The first layer, the O-Horizon, is the superficial top layer of soil that is primarily composed of decaying organic matter (humus), living organisms and fresh soil. This layer of the soil boasts a brown or black colour due to its organic composition and is usually very thin.

Detailed explanation-2: -The topsoil layer is a mixture of sand, silt, clay and broken down organic matter, called humus. Humus is rich, highly decomposed organic matter mostly made from dead plants, crunched-up leaves, dead insects and twigs. Topsoil is the home of living things and the materials that they make or they change.

Detailed explanation-3: -Humus is the stable fraction of the soil organic matter that is formed from decomposed plant and animal tissue. It is the final product of decomposition.

Detailed explanation-4: -Soil is made up of distinct horizontal layers; these layers are called horizons. They range from rich, organic upper layers (humus and topsoil) to underlying rocky layers ( subsoil, regolith and bedrock). The top, organic layer of soil, made up mostly of leaf litter and humus (decomposed organic matter).