Trends in ecological research during the last three decades--a systematic review.

It is thought that the science of ecology has experienced conceptual shifts in recent decades, chiefly from viewing nature as static and balanced to a conception of constantly changing, unpredictable, complex ecosystems. Here, we ask if these changes are reflected in actual ecological research over the last 30 years. We surveyed 750 articles from the entire pool of ecological literature and 750 articles from eight leading journals. Each article was characterized according to its type, ecological domain, and applicability, and major topics. We found that, in contrast to its common image, ecology is still mostly a study of single species (70% of the studies); while ecosystem and community studies together comprise only a quarter of ecological research. Ecological science is somewhat conservative in its topics of research (about a third of all topics changed significantly through time), as well as in its basic methodologies and approaches. However, the growing proportion of problem-solving studies (from 9% in the 1980s to 20% in the 2000 s) may represent a major transition in ecological science in the long run.

Naturalistic stress and cortisol response to awakening: adaptation to seafaring.

Study of the hypothalamic-pituitary adrenal (HPA) axis has been critical to advancing our understanding of human adaptation to stress. The cortisol response to awakening (CRA) is a potentially useful measure for understanding group and individual differences in HPA axis regulation. In this study, the CRA was examined in the context of a naturalistic stressor--a 6-week voyage of work and study aboard an oceangoing ship, including both experienced and novice sailors. Thirty-one subjects provided weekday and weekend baseline CRA data onshore prior to boarding, followed by three CRAs at sea and one shore leave CRA. Subjective measures of sleep, stress and control were also collected. Results suggest that novice sailors' cortisol response to awakening was elevated at sea relative to both a shoreside weekend and a shore leave during the voyage, but the most striking elevation was found during a workday onshore. Inexperienced students' profiles changed differently over the course of the voyage from those of professional crew. CRAs were not affected by sleep variables and were not predicted by subjective ratings. These data support the value of the cortisol response to awakening as a neuroendocrine marker of HPA regulatory responses to a naturalistic stressor, influenced by changes in work and living environment, and perhaps prior experience with the stressor.