Which process in the ecosystem is hampered by the presence of toxic substances?

The presence of toxic substances in the ecosystem can significantly disrupt the process of nitrogen fixation. Nitrogen fixation is carried out by certain bacteria, many of which are sensitive to toxins in their environment. These bacteria play a crucial role in converting atmospheric nitrogen into ammonia or related compounds that plants can use for growth. When toxic substances such as heavy metals, pesticides, or industrial chemicals contaminate the soil or water, they can inhibit the activity of these beneficial microorganisms, leading to a decrease in nitrogen availability for plants. This can cause a ripple effect throughout the ecosystem, impacting plant growth, soil health, and the overall productivity of the ecosystem.

While other processes like photosynthesis, cellular respiration, and transpiration might also be affected by environmental toxins, nitrogen fixation is particularly vulnerable due to its reliance on specific microorganisms and the delicate balance of soil chemistry.