The green–blue swing: plasticity of plankton food‐webs in response to coastal oceanographic dynamics

The internal organization of plankton communities plays a key role in biogeochemical cycles and in the functioning of aquatic ecosystems. In this study, the structure of a marine plankton community (including both unicellular and multicellular organisms) was inferred by applying an ecological network approach to species abundances observed weekly at the long‐term ecological research station MareChiara (LTER‐MC) in the Gulf of Naples (Tyrrhenian Sea, Mediterranean Sea) in the summers of 2002–2009. Two distinct conditions, characterized by different combination of salinity and chlorophyll values, alternated at the site: one influenced by coastal waters, herein named ‘green’, and the other reflecting more offshore conditions, named ‘blue’. The green and blue ‘phases’ showed different keystone biological elements: namely, large diatoms and small‐sized flagellates, respectively. Several correlations amongst species belonging to different trophic groups were found in both phases (connectance ~0.30). In the green phase, several links between phytoplankton and mesozooplankton and within the latter were detected, suggesting matter flow from microbes up to carnivorous zooplankton. A microbial‐loop‐like sub‐web, including mixo‐ and heterotrophic dinoflagellates and ciliates, was present in the green phase, but it was relatively more important in the blue phase. The latter observation suggests a more intense cycling of matter at the microbial trophic level in the blue phase. These results show that different modes of ecological organization can emerge from relatively small changes in the composition of aquatic communities coping with environmental variability. This highlights a significant plasticity in the internal structure of plankton webs, which should be taken into account in predictions of the potential effects of climatic oscillations on aquatic ecosystems and biogeochemical cycles therein.     

Disaster education for landslide risk reduction: an experience in a public school in Rio de Janeiro State,Brazil

Public policies for reducing the disaster risk associated with landslides in Brazil, based almost solely on the implementation of engineering works to stabilise hillsides, have proved ineffective, with this type of disaster becoming more common and more severe. There is therefore an urgent need to form a culture that encourages the public to participate directly in disaster management and develops community capacity, which requires a broad disaster education programme on formal, non-formal and informal levels. Given the recent approach to the topic, this study aims to contribute to the development of a disaster education methodology for landslides, based on an experience that was coordinated by the authors within formal education. The experience was implemented in a state school in the city of Niterói (Rio de Janeiro State, Brazil) which is recurrently affected by disasters associated with landslides. The issue of disasters associated with landslides was addressed in a one-semester course, using the theory of meaningful learning and a range of pedagogical tools in both theory and practical classes, for a total period of 16 h. The educational activities were preceded by a landslide risk perception survey and teacher training. The study concluded that the course promoted interactive and participatory learning, a connection to the real problem in the field and an affective relationship with the issue.     

Paradigm shifts in community ecology: Open versus closed units,challenges and limits of connectivity studies

Due to the presence of the complex life cycles involving a benthic adult and a pelagic larval phase, the study of benthic community dynamics cannot ignore investigations of the processes occurring in the water column. Current investigations focus mainly on larval dispersal from an evolutionary and a biogeographic perspective, taking into account also population connectivity, conservation planning and coastal management. In the present paper we underline the need to improve knowledge of the main traits of marine invertebrate life cycles, highlighting the limits and challenges of current approaches. Firstly, we summarized the changing approaches within community studies, following the paradigm shifts found in recent marine ecological research, from supply‐side ecology to connectivity, and involving the concepts of open and closed populations. Secondly, we analysed the main larval traits influencing dispersal, paying particular attention to pelagic larval duration in light of the few available data for connectivity studies. The difficulty in estimating many of the main traits of larval ecology make numerical simulation fundamental for a better understanding of the relationship between propagule dispersal and seawater dynamics, both being highly variable. We conclude that some essential biological information is still lacking for the proper integration of the modeling approaches. Thus it is necessary to further investigate the life‐cycle traits and physiological and ecological characteristics of each species, an approach known as autecology or natural history. All too frequently modern ecologists ignore such reductionist approaches, although they are essential for a full understanding of processes, such as connectivity and metapopulation dynamics.