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Rapid effects of marine reserves via larval dispersal

Richard Cudney Bueno (2009, [Artículo])

Marine reserves have been advocated worldwide as conservation and fishery management tools. It is argued that they can protect ecosystems and also benefit fisheries via density-dependent spillover of adults and enhanced larval dispersal into fishing areas. However, while evidence has shown that marine reserves can meet conservation targets, their effects on fisheries are less understood. In particular, the basic question of if and over what temporal and spatial scales reserves can benefit fished populations via larval dispersal remains unanswered. We tested predictions of a larval transport model for a marine reserve network in the Gulf of California, Mexico, via field oceanography and repeated density counts of recently settled juvenile commercial mollusks before and after reserve establishment. We show that local retention of larvae within a reserve network can take place with enhanced, but spatially-explicit, recruitment to local fisheries. Enhancement occurred rapidly (2 yrs), with up to a three-fold increase in density of juveniles found in fished areas at the downstream edge of the reserve network, but other fishing areas within the network were unaffected. These findings were consistent with our model predictions. Our findings underscore the potential benefits of protecting larval sources and show that enhancement in recruitment can be manifested rapidly. However, benefits can be markedly variable within a local seascape. Hence, effects of marine reserve networks, positive or negative, may be overlooked when only focusing on overall responses and not considering finer spatially-explicit responses within a reserve network and its adjacent fishing grounds. Our results therefore call for future research on marine reserves that addresses this variability in order to help frame appropriate scenarios for the spatial management scales of interest. © 2009 Cudney-Bueno et al.

article, environmental monitoring, fishery, larva, marine environment, marine species, Mexico, mollusc, nonhuman, oceanography, prediction, animal, biology, environmental protection, food industry, geography, growth, development and aging, larva, met CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA

Shopping for Ecological Indices? On the Use of Incidence-Based Species Compositional Similarity Measures

IAN MACGREGOR FORS FEDERICO ESCOBAR SARRIA JUAN FERNANDO ESCOBAR IBAÑEZ NATALIA MESA SIERRA FREDY ALEXANDER ALVARADO ROBERTO Rafael Rueda Hernández CLAUDIA ELIZABETH MORENO ORTEGA Ina Falfán ERICK JOAQUIN CORRO MENDEZ Eduardo Octavio Pineda Arredondo Amandine Bourg JOSE LUIS AGUILAR LOPEZ (2022, [Artículo])

"β-diversity has been under continuous debate, with a current need to better understand the way in which a new wave of measures work. We assessed the results of 12 incidence-based β-diversity indices. Our results of gradual species composition overlap between paired assemblages considering progressive differences in species richness show the following: (i) four indices (β-2, β-3, β-3.s, and βr) should be used cautiously given that results with no shared species retrieve results that could be misinterpreted; (ii) all measures conceived specifically as partitioned components of species compositional dissimilarities ought to be used as such and not as independent measures per se; (iii) the non-linear response of some indices to gradual species composition overlap should be interpreted carefully, and further analysis using their results as dependent variables should be performed cautiously; and (iv) two metrics (βsim and βsor) behave predictably and linearly to gradual species composition overlap. We encourage ecologists using measures of β-diversity to fully understand their mathematical nature and type of results under the scenario to be used in order to avoid inappropriate and misleading inferences."

Beta diversity Nestedness Replacement Richness difference Species turnover BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

Seed integrity, effect of temperature and storage time on germination of Populus luziarum and P. primaveralepensis, endangered subtropical species from Mexico

César Jacobo Pereira MIGUEL ANGEL MUÑIZ CASTRO JOSE ANTONIO VAZQUEZ GARCIA Joel David Flores Rivas ALEJANDRO MUÑOZ URIAS FRANCISCO MARTIN HUERTA MARTINEZ (2022, [Artículo])

"Background: Populus luziarum and P. primaveralepensis are endemic species of western Mexico; growing in riparian forests they are critically endangered. The best way to conserve their seeds is unknown, which could be limiting for their conservation.

Hypothesis: The germinability of both subtropical species is like that of boreal and template Salicaceae species that disperse seeds in spring and early summer, as they germinate quickly with high percentages, and rapidly lose their viability when stored at ambient temperature.

Studied species: Populus luziarum and P. primaveralepensis. Study site and dates: Western Trans-Mexican Volcanic Belt. Jalisco, Mexico. October 2019.

Methods: The physical integrity of the seeds was assessed by X-ray imaging and compared with germinability. In addition, the effect of storage time (nine weeks) under two temperatures (4 and 21 °C) on the percentage and mean germination rate was evaluated.

Results: No significant differences were found between physical integrity and germination in freshly collected seeds for both species. Germination in the first 24 hrs was 91 and 95 % for Populus luziarum and P. primaveralepensis, respectively (week 0). Germination percentages were lower when stored at 21 °C, but P. primaveralepensis was decreased more slowly.

Conclusions: Seeds of subtropical Populus respond similarly to those of species from temperate and boreal climates with early seed dispersal, a crucial condition for establishing ex situ reforestation and conservation programs."

Salicaceae Seed physical integrity Seed storage conditions Subtropical endemic species White poplars BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) BIOLOGÍA VEGETAL (BOTÁNICA)