Ecosystem modeling, a pillar of the systems ecology paradigm (SEP), addresses questions such as, how much carbon and nitrogen are cycled within ecological sites, landscapes, or indeed the earth system? Or how are human activities modifying these flows? Modeling, when coupled with field and laboratory studies, represents the essence of the SEP in that they embody accumulated knowledge and generate hypotheses to test understanding of ecosystem processes and behavior. Initially, ecosystem models were primarily used to improve our understanding about how biophysical aspects of ecosystems operate. However, current ecosystem models are widely used to make accurate predictions about how large-scale phenomena such as climate change and management practices impact ecosystem dynamics and assess potential effects of these changes on economic activity and policy making. In sum, ecosystem models embedded in the SEP remain our best mechanism to integrate diverse types of knowledge regarding how the earth system functions and to make quantitative predictions that can be confronted with observations of reality. Modeling efforts discussed are the Century ecosystem model, DayCent ecosystem model, Grassland Ecosystem Model ELM, food web models, Savanna model, agent-based and coupled systems modeling, and Bayesian modeling.

The systems ecology paradigm (SEP) is presented as the right science and analytical approach at the right time for resolving many of the Earth’s natural resource, environmental, and societal challenges. SEP embodies two major parts. One, the systems ecology approach, which is the holistic, systems thinking perspective and methodology developed for the rigorous study of ecosystems, including humans. Two, the use of ecosystem science, the vast body of scientific knowledge, much of which has been assembled using the ecosystem and systems ecology approaches. The fundamental philosophy, evolution, and application of the SEP are defined in this chapter. The organizing principles of the SEP include: many problems are complex and complicated and may have multiple causes; precise definitions of problems and their spatial, temporal, and organizational hierarchical scales are critical; collaborative decision making including scientists, technical and administrative staff members, and essential stakeholders is essential; transparent, honest, and effective communication is required; globalization of collaboration within interdisciplinary networks has been a hallmark of the paradigm; and integration of simulation modeling, field and laboratory studies has proven indispensable for many scientific breakthroughs. A call for integration of transdisciplinary science, policy making, and management is presented.

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.

The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.