SignificanceMeeting human needs while sustaining ecosystems and the benefits they provide is a global challenge. Coastal marine systems present a particularly important case, given that >50% of the world’s population lives within 100 km of the coast and fisheries are the primary source of protein for >1 billion people worldwide. Our integrative analysis here yields an understanding of the sustainability of coupled social-ecological systems that is quite distinct from that provided by either the biophysical or the social sciences alone and that illustrates the feasibility and value of operationalizing the social-ecological systems framework for comparative analyses of coupled systems, particularly in data-poor and developing nation settings.

Aim Correlative distribution models have been used to identify potential climatic controls of mangrove range limits, but there is still uncertainty about the relative importance of these factors across different regions. To provide insights into the strength of climatic control of different mangrove range limits, we tested whether temporal variability in mangrove abundance increases near range limits and whether this variability is correlated with climatic factors thought to control large‐scale mangrove distributions. Location North and South America. Time period 1984–2011. Major taxa studied Avicennia germinans, Avicennia schuaeriana, Rhizophora mangle, Laguncularia racemosa. Methods We characterized temporal variability in the enhanced vegetation index (EVI) at mangrove range limits using Landsat satellite imagery collected between 1984–2011. We characterized greening trends at each range limit, examined variability in EVI along latitudinal gradients near each range limit, and assessed correlations between changes in EVI and temperature and precipitation. Results Spatial variability in mean EVI was generally correlated with temperature and precipitation, but the relationships were region specific. Greening trends were most pronounced at range limits in eastern North America. In these regions variability in EVI increased toward the range limit and was sensitive to climatic factors. In contrast, EVI at range limits on the Pacific coast of North America and both coasts of South America was relatively stable and less sensitive to climatic variability. Main conclusions Our results suggest that range limits in eastern North America are strongly controlled by climate factors. Mangrove expansion in response to future warming is expected to be rapid in regions that are highly sensitive to climate variability (e.g. eastern North America), but the response in other range limits (e.g. South America) is likely to be more complex and modulated by additional factors such as dispersal limitation, habitat constraints, and/or changing climatic means rather than just extremes.

. 2018. Designing connected marine reserves in the face of global warming. Global Change Biology 24: e671-e691. https://doi.org/10. 1111/gcb.13989 Designing connected marine reserves in the face of global warming Jorge G. Álvarez-Romero AbstractMarine reserves are widely used to protect species important for conservation and fisheries and to help maintain ecological processes that sustain their populations, including recruitment and dispersal. Achieving these goals requires well-connected networks of marine reserves that maximize larval connectivity, thus allowing exchanges between populations and recolonization after local disturbances. However, global warming can disrupt connectivity by shortening potential dispersal pathways through changes in larval physiology. These changes can compromise the performance of marine reserve networks, thus requiring adjusting their design to account for ocean warming. To date, empirical approaches to marine prioritization have not considered larval connectivity as affected by global warming. Here, we propose a framework for designing marine reserve networks that integrates graph theory and changes in larval connectivity due to potential reductions in planktonic larval duration (PLD) associated with ocean warming, given current socioeconomic constraints. Using the Gulf of California as case study, we assess the benefits and costs of adjusting networks to account for connectivity, with and without ocean warming. We compare reserve networks designed to achieve representation of species and ecosystems with networks designed to also maximize connectivity under current and future ocean-warming scenarios. Our results indicate that current larval connectivity could be reduced significantly under ocean warming because of shortened PLDs. Given the potential changes in connectivity, we show that our graph-theoretical approach based on centrality (eigenvector and distance-weighted fragmentation) of habitat patches can help design better-connected marine reserve networks for the future with equivalent costs. We found that maintaining dispersal connectivity incidentally through representation-only reserve design is unlikely, particularly in regions with strong asymmetric patterns of dispersal connectivity. Our results support previous studies suggesting that, given potential reductions in PLD due to ocean warming, future marine reserve networks would require more and/or larger reserves in closer proximity to maintain larval connectivity.

Rhodoliths provide a stable and three-dimensional habitat to which other seaweeds and invertebrates can attach. Although ecological factors affecting rhodolith beds have been studied, little is known about the effect of rhodolith species and growth-form on associated fauna. Experiments were conducted at three rhodolith beds in the central-west Gulf of California. Faunal abundance differed significantly in relation to rhodolith-forming species, but no significant differences were observed between different growth-forms. Rhodolith structure differs between the species Lithophyllum margaritae and Neogoniolithon trichotomum, and the combination of structure differences and rhodolith abundances may be responsible of the significant differences in faunal abundance and richness. Crustaceans, polychaetes and molluscs were the most important taxa in all three rhodolith beds. The amphipod species Pontogeneia nasa and the cnidarian Aiptasia sp. were dominant in both rhodolith beds, El Requesó n and Isla Coyote, in Bahía Concepció n. The Isla Coronados rhodolith bed was dominated by an unidentified harpacticoid copepod (Copepoda sp.1). Rhodolith species is more important than growth-form in determining abundance and richness of the associated fauna. Nevertheless, factors such as wave motion, depth, bioturbation and others should be considered when studying organisms associated with rhodolith beds.

Publication InformationHinojosa-Arango G., Maggs C. A. and Johnson M.P. Like a rolling stone: the mobility of maerl (corallinaceae) and the neutrality of the associated assemblages. Ecology 90, 517-528. PublisherEcological Society of America however, about how natural disturbance regimes affect the species associated with maerl. This 18 study compared the richness, animal abundance and algal biomass of maerl-associated species 19 over a two year period in a wave disturbed and a sheltered maerl bed. Changes in associated 20 species over time were assessed for departures from a neutral model, where the dissimilarity 21 between samples reflects random sampling from a common species pool. Algal biomass and 22 species richness at the wave exposed site and on stabilized maerl at the sheltered site were 23 reduced at times of higher wind speeds. The changes in species richness were not 24 distinguishable from a neutral model, implying that algal species were added at random to the 25 assemblage as the level of disturbance lessened. Results for animal species were more mixed. 26Although mobile species were less abundant during windy periods at the exposed site, both 27 neutral and non-neutral patterns were evident in the assemblages. Artificial stabilization of 28 maerl had inconsistent effects on the richness of animals, but always resulted in more attached 29 algal species. While the results show that the response of a community to disturbance can be 30 neutral, the domain of neutral changes in communities may be relatively small. Alongside non-31 neutral responses to natural disturbance, artificial stabilization always resulted in an 32 assemblage that was more distinct than would be expected under random sampling from a 33 common pool. Community responses to stabilization treatments did not consistently follow the 34 predictions of the dynamic equilibrium model, intermediate disturbance model or a facilitation 35 model. These inconsistencies may reflect site-specific variation in both the disturbance regime 36 and the adjacent habitats that provide source populations for many of the species found 37 associated with maerl. 38 39