Plants: Carbon Source or Carbon Sink
There are many opinions on the role of plants in carbon in the world. Either plants are carbon sources, or they are carbon sinks, there is no agreement. To understand the reason, we should investigate its root cause.

The growth of plants depends on photosynthesis. During the day, under light, plants use chlorophyll as a medium to absorb carbon dioxide, which is phased with water to produce organic matter and release oxygen. In this process, plants sequester carbon in their bodies, accumulating it in their branches, roots, and leaves, thus forming a carbon sink. The mountains and forests are vast, the trees are lush, and the amount of carbon sequestered is huge, which is of great help in slowing down the greenhouse effect.

However, plants also have carbon sources. First, plants breathe, day and night, consume organic matter in their bodies and release carbon dioxide. Although photosynthesis is stronger than respiration during the day, carbon is sequestered on the whole; however, there is no light at night, only respiration, and carbon is released outside. Second, plants die, residues decompose, and under the action of microorganisms, organic matter explains carbon. If forest fires ravage, plants burn quickly, and a large amount of carbon enters the gas.

Furthermore, environmental changes and human intervention can change the state of carbon sources and carbon sinks in plants. Climate anomalies affect plant photosynthesis and respiration. Drought and high temperature cause weak photosynthesis and strong respiration, and reduce carbon sink capacity. Deforestation, destruction of vegetation, reduction of carbon sequestration, increase of rot, and obvious role of carbon sources.

In summary, plants are not simple carbon sources or carbon sinks, and their functions vary from time to time and according to context. Humans should take good care of the environment, promote it as a good carbon sink, slow down the trend of global warming, and maintain ecological balance.