The systems ecology paradigm (SEP) emerged in the late 1960s at a time when societies throughout the world were beginning to recognize that our environment and natural resources were being threatened by their activities. Management practices in rangelands, forests, agricultural lands, wetlands, and waterways were inadequate to meet the challenges of deteriorating environments, many of which were caused by the practices themselves. Scientists recognized an immediate need was developing a knowledge base about how ecosystems function. That effort took nearly two decades (1980s) and concluded with the acceptance that humans were components of ecosystems, not just controllers and manipulators of lands and waters. While ecosystem science was being developed, management options based on ecosystem science were shifting dramatically toward practices supporting sustainability, resilience, ecosystem services, biodiversity, and local to global interconnections of ecosystems. Emerging from the new knowledge about how ecosystems function and the application of the systems ecology approach was the collaboration of scientists, managers, decision-makers, and stakeholders locally and globally. Today’s concepts of ecosystem management and related ideas, such as sustainable agriculture, ecosystem health and restoration, consequences of and adaptation to climate change, and many other important local to global challenges are a direct result of the SEP.

Fundamental knowledge about the processes that control the functioning of the biophysical workings of ecosystems has expanded exponentially since the late 1960s. Scientists, then, had only primitive knowledge about C, N, P, S, and H2O cycles; plant, animal, and soil microbial interactions and dynamics; and land, atmosphere, and water interactions. With the advent of systems ecology paradigm (SEP) and the explosion of technologies supporting field and laboratory research, scientists throughout the world were able to assemble the knowledge base known today as ecosystem science. This chapter describes, through the eyes of scientists associated with the Natural Resource Ecology Laboratory (NREL) at Colorado State University (CSU), the evolution of the SEP in discovering how biophysical systems at small scales (ecological sites, landscapes) function as systems. The NREL and CSU are epicenters of the development of ecosystem science. Later, that knowledge, including humans as components of ecosystems, has been applied to small regions, regions, and the globe. Many research results that have formed the foundation for ecosystem science and management of natural resources, terrestrial environments, and its waters are described in this chapter. Throughout are direct and implicit references to the vital collaborations with the global network of ecosystem scientists.

Ecosystem science and the systems ecology paradigm co-evolved starting in the late 1960s within the milieu of substantial research funding from the US National Science Foundation-supported US International Biological Program (IBP). Nationally, educational programs focusing on ecosystem structure and functioning, and mathematical modeling, were slow to develop except at Colorado State University (CSU). There, leaders in the Natural Resource Ecology Laboratory (NREL) and the Department of Range Science (DRS) established internationally recognized interdisciplinary programs and outreach in basic and applied ecosystem science and systems ecology. Operating from the sound research base within a major Land Grant University (CSU), the NREL, with IBP funding, supported many graduate students housed in the academic DRS. As the systems ecology approach expanded, other ecosystem-focused research programs developed, and graduate students entered other academic departments. Outgrowths from the early diffused educational training were innovative cross-departmental and cross-college programs addressing the systems ecology paradigm. Recently, a new Department of Ecosystem Science and Sustainability was established housing both graduate and undergraduate programs. As formal academic training developed on-campus, environmental literacy efforts were developed, including: training programs for K-12 students and teachers; online distance education programs; Citizen Science training; and numerous institutes, short courses, and workshops.