This paper addresses questions of community and patch stability as defined by the population biology of dominant plants in the context of different areas within a large kelp forest. We ask ( 1) "Do large-scale episodic events override biological mechanisms as major community structuring processes?", (2) "Are different local areas characterized by different processes?", and (3) "How persistent are the patches or biological structure over decadal and local spatial scales?" We evaluate these questions with regard to the effects of various types of disturbance for as much as three decades on the populations of several species of kelp in the large kelp forest off Point Lorna, San Diego, California. The most sensitive population factors we studied include recruitment, density, and survivorship. Patch stability was evaluated with regard to the persistence of patches already well established in 1971-1972. The study sites offer a cross-shore transect through the central part of a large kelp forest at depths of8, 12, 15, 18, and 21m; two additional sites at the north and south ends of the forest offer a longshore transect along the 18-m contour.There were marked differences among the decades with regard to the intensity of the disturbances. Compared with the 1980s, the two preceding decades were relatively benign. The 1980s had two extreme disturbance events: the 1982-1984 El Nino-Southern Oscillation (ENSO) was the most severe El Nino event in the last century, which included very warm, nutrient-depleted water, and a short but intense storm in January 1988 appeared to have been the most severe in perhaps 200 yr. The storm changed age-specific kelp mortality patterns and caused the first large-scale understory mortality in several decades. By sweeping away drift algae it caused intense local urchin grazing. The storm was followed by a strong La Niiia event marked by cool, nutrient-rich water in 1988-1989. Differences in kelp recruitment and survivorship in different areas of the kelp forest are influenced by gradients in longshore currents, temperature, light, wave energy, floc, planktonic propagules, and physical disturbance. The areas are characterized by different plant population patterns and the effects of several species of herbivores. The massive disturbances of the 1980s obliterated much of the structure in the kelp forest. Certainly the disturbances caused many lag effects including outbreaks of understory algae such as Desmarestia ligulata, intraspecific competition, changes in grazing patterns, etc., which in tum resulted in between-area variation in recovery rates. However, in all cases this variation was overshadowed by the overwhelming competitive dominance of Macrocystis pyrifera. Most of the understory patches on the transect lines, some of which had persisted for 7 yr, died out by the end of 1990.The population biology of Macrocystis was remarkably similar in most areas, as the cohort longevity and survivorship curves were very similar, and the plant and stipe densities tended to level off in only a few ...

The detection of trends in ecosystems depends upon (1) a good description of the foundation or benchmark against which changes are measured and (2) a distinction between natural and anthropogenic changes. Patterns and mechanisms observed over 25 years in a large kelp forest suggest that definition of a meaningful benchmark is impossible, because many of the large animals have been gone for years to decades, and kelps are sensitive to large-scale, low-frequency El Niñ o-Southern Oscillation events and longer term regime shifts. A shift in the oceanographic climate has significantly reduced the average size and carrying capacity of the dominant plant. The animals that have been functionally removed from the community include sea otters, black sea bass, yellowtail, white sea bass, and abalones. Other species are still present, but fisheries have had huge effects on the abundances, size-frequencies, and/or spatial distributions of sheephead, kelp bass, rays, flatfish, rock fish, spiny lobsters, and red sea urchins. Now even sea cucumbers, crabs, and small snails are subject to unregulated fishing. The plants continue to exist without a hint of the effects of the loss of so much animal biomass. Furthermore, most of the megafauna have been removed with very little documentation or historical understanding of what the natural community was like. Thus, our ability to separate anthropogenic impacts from the ''natural'' dynamics of the system is severely compromised. We discuss the importance of both an ecosystem focus on productivity and careful monitoring of as many populations as possible. In addition, we show that this community is not tightly integrated with mutual dependencies; hence, many species can be removed without much affecting the rest of the ecosystem.

This paper integrates long‐term descriptive and experimental studies of the effects of ocean climate on inter‐ and intraspecific competition, as expressed by recruitment, density, survivorship, growth, and reproduction of the most conspicuous kelp species in the Point Loma kelp forest community off San Diego, California, USA. The species included Macrocystis pyrifera, with a floating canopy; Pterygophora californica and Eisenia arborea, which rely on stipes to support their canopy; Laminaria farlowii, with a prostrate canopy; and a speciose red algal turf. To evaluate the roles of large‐scale oceanographic processes on biological processes across important depth gradients, the study was carried out over nine years during a cold‐water, nutrient‐rich La Niña event (1988–1989) and a warm‐water, nutrient‐stressed El Niño period (1992–1994), over a depth range of 8–23 m. This depth range encompassed strong physical gradients involving factors that are critical for kelp growth, including bottom temperatures (correlated with nutrients) and light levels. To examine interactions among these kelps, we established clearings across the depth gradient and then manipulated Macrocystis recruit densities. The demographic responses offer an understanding of the “fundamental” vs. “realized” niches of these species. Evaluating these patterns, as they are influenced by inter‐ and intraspecific competition, offers insights into the “realized niches” of the kelps. With the exception of some understory effects on Macrocystis recruitment and some evidence of intraspecific competition during the nutrient‐rich La Niña conditions, we found little influence of competitive effects on Macrocystis. The response of Pterygophora to manipulations and disturbances suggests light‐limited recruitment, and competition with Macrocystis was exhibited via reduced growth and reproduction, but not survivorship. No nutrient stress was observed in Pterygophora reproduction. Eisenia recruitment is rare, but once established, juveniles had very good survivorship, with growth and reproduction reduced by depth; the Macrocystis treatment was more important than depth, suggesting the importance of light to Eisenia recruitment and growth. In general, Macrocystis had massive effects on Laminaria growth and reproduction, the strength varying with depth. In particular, there were very strong effects of competition with Macrocystis during the nutrient‐rich La Niña period when Macrocystis had a dense surface canopy. In addition to the Macrocystis effects, there were some significant Pterygophora effects on Laminaria growth during El Niño. The strongest biological definition of realized niches occurred during the nutrient‐rich La Niña period, especially in shallow depths. One of the most important conclusions of this paper is the appreciation of the importance of scaling in time to include oceanographic climate. There are many seasonal patterns, but the interannual scales that encompass El Niños and La Niñas, and ultimately the interdecadal‐scale oceanographic regime shi...

The detection of trends in ecosystems depends upon (1) a good description of the foundation or benchmark against which changes are measured and (2) a distinction between natural and anthropogenic changes. Patterns and mechanisms observed over 25 years in a large kelp forest suggest that definition of a meaningful benchmark is impossible, because many of the large animals have been gone for years to decades, and kelps are sensitive to large‐scale, low‐frequency El Niño–Southern Oscillation events and longer term regime shifts. A shift in the oceanographic climate has significantly reduced the average size and carrying capacity of the dominant plant. The animals that have been functionally removed from the community include sea otters, black sea bass, yellowtail, white sea bass, and abalones. Other species are still present, but fisheries have had huge effects on the abundances, size–frequencies, and/or spatial distributions of sheephead, kelp bass, rays, flatfish, rock fish, spiny lobsters, and red sea urchins. Now even sea cucumbers, crabs, and small snails are subject to unregulated fishing. The plants continue to exist without a hint of the effects of the loss of so much animal biomass. Furthermore, most of the megafauna have been removed with very little documentation or historical understanding of what the natural community was like. Thus, our ability to separate anthropogenic impacts from the “natural” dynamics of the system is severely compromised. We discuss the importance of both an ecosystem focus on productivity and careful monitoring of as many populations as possible. In addition, we show that this community is not tightly integrated with mutual dependencies; hence, many species can be removed without much affecting the rest of the ecosystem.

Climate change is already having adverse impacts on ecosystems, communities and economic activities through higher temperatures, prolonged droughts, and more frequent extremes. However, a gap remains between public understanding, scientific knowledge about climate change, and changes in behaviour to effect adaptation. 'Serious games'-games used for purposes other than entertainment-are one way to reduce this adaptation deficit by enhancing opportunities for social learning and enabling positive action. Games can provide communities with the opportunity to interactively explore different climate futures, build capability and capacity for dealing with complex challenges, and socialise adaptation priorities with diverse publics. Using systematic review methods, this paper identifies, reviews, synthesises and assesses the literature on serious games for climate change adaptation. To determine where and how impact is achieved, we draw on an evaluation framework grounded in social learning, to assess which combinations of cognitive (knowledge and thinking), normative (norms and approaches) and relational (how people connect and network building) learning are achieved. Results show that factors influencing the overall success in influencing behaviour and catalysing learning for adaptation include generating high levels of interand intra-level trust between researchers, practitioners and community participants; strong debriefing and evaluation practices; and the use of experienced and knowledgeable facilitators. These results can help inform future game design, and research methodologies to develop robust ways for engaging with stakeholders and end users, and enhance learning effects for resilient climate futures.

No abstract

ABSTRACT. Environmental problems caused by human activities are increasing; biodiversity is disappearing at an unprecedented rate, soils are being irreversibly damaged, freshwater is increasingly in short supply, and the climate is changing.To reverse or even to reduce these trends will require a radical transformation in the relationship between humans and the natural environment. Just how this can be achieved within, at most, a few decades is unknown, but it is clear that academia must play a crucial role. Many believe, however, that academic institutions need to become more effective in helping societies move toward sustainability. We first synthesize current thinking about this crisis of research effectiveness. We argue that those involved in producing knowledge to solve societal problems face three particular challenges: the complexity of real-world sustainability problems, maintaining impartiality when expert knowledge is used in decision making, and ensuring the salience of the scientific knowledge for decision makers. We discuss three strategies to meet these challenges: conducting research in interdisciplinary teams, forming research partnerships with actors and experts from outside academia, and framing research questions with the aim of solving specific problems (problem orientation). However, we argue that implementing these strategies within academia will require both cultural and institutional change. We then use concepts from transition management to suggest how academic institutions can make the necessary changes. At the level of system optimization, we call for: quality criteria, career incentives, and funding schemes that reward not only disciplinary excellence but also achievements in inter-/transdisciplinary work; professional services and training through specialized centers that facilitate problem-oriented research and reciprocal knowledge exchange with society; and the integration of sustainability and inter-/transdisciplinary research practices into all teaching curricula. At the level of system innovation, we propose radical changes in institutional structures, research and career incentives, teaching programs, and research partnerships. We see much value in a view of change that emphasizes the complementarity of system innovation and system optimization. The goal must be a process of change that preserves the traditional strengths of academic research, with its emphasis on disciplinary excellence and scientific rigor, while ensuring that institutional environments and the skills, worldviews, and experiences of the involved actors adapt to the rapidly changing needs of society.

No abstract