OBJECTIVE FORESTRY

Detailed explanation-1: -So, the correct option is ‘Photosynthesis by producers’.

Detailed explanation-2: -Trees also release carbon dioxide to the atmosphere as a function of their physiology. When some or all parts of a tree decompose after death or burn during fire, the carbon is released back to the atmosphere. Thus, the amount of carbon in forests closely mirrors the natural cycle of tree growth and death.

Detailed explanation-3: -Natural sources of carbon dioxide include most animals, which exhale carbon dioxide as a waste product. Human activities that lead to carbon dioxide emissions come primarily from energy production, including burning coal, oil, or natural gas.

Detailed explanation-4: -Carbon dioxide is added to the atmosphere naturally when organisms respire or decompose (decay), carbonate rocks are weathered, forest fires occur, and volcanoes erupt. Carbon dioxide is also added to the atmosphere through human activities, such as the burning of fossil fuels and forests and the production of cement.