**Introduction to the Term Ecosystem**

The term "ecosystem" was introduced by Arthur Tansley, an English botanist, in the year 1935. Tansley was a pioneer in the field of ecology and his contribution to the understanding of the interrelationships between organisms and their environment was significant.

**Explanation**

- **Arthur Tansley**: Arthur Tansley was an influential figure in the field of ecology during the early 20th century. He is known for his work on plant ecology and his contributions to the development of the concept of ecosystems.

- **Introduction of the Term**: In his 1935 paper titled "The Use and Abuse of Vegetational Concepts and Terms," Tansley introduced the term "ecosystem" to describe the complex interactions between organisms and their environment.

- **Definition of Ecosystem**: Tansley defined an ecosystem as "the whole system, including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment." This definition emphasized the interconnectedness and interdependence of living organisms and their surrounding physical environment.

- **Holistic Perspective**: Tansley's concept of the ecosystem was a departure from the reductionist approach that was prevalent at the time. He emphasized the need to study ecological systems as a whole, considering the interactions between organisms and their environment, rather than focusing solely on individual species.

- **Influence on Ecological Thinking**: The introduction of the term "ecosystem" by Tansley revolutionized the field of ecology. It provided a framework for studying the complex interactions between living organisms and their environment, and helped ecologists understand the interconnectedness of ecological processes.

**Conclusion**

In conclusion, the term "ecosystem" was introduced by Arthur Tansley in 1935. Tansley's concept of the ecosystem emphasized the interrelationships between organisms and their environment, and it revolutionized the field of ecology. His work laid the foundation for the study of ecological systems as a whole, and his contributions continue to be influential in the field of ecology to this day.