Answer:
biosphere
Step-by-step explanation:
The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth.
The biosphere refers to the regions of the surface and atmosphere of the earth or another planet occupied by living organisms.
Plants are responsible for taking in carbon in nature. When more trees are planted, carbon is absorbed by plants which is a component of the biosphere. Hence planting more trees means increasing the intake of carbon into the biosphere.