Article has an altmetric score of 5 Effect of extreme climatic events resulting in prolonged precipitation on the reproductive output of sea turtles

Anthropogenic climate change is predicted to increase the variation in storm patterns in some areas in the coming decades. This variation in mean rainfall and increase in mean temperature could increase the extinction risk of species with temperature dependent sex determination. Taking into account that sea turtle reproductive output depends on climatic conditions, such as precipitation and temperature, extreme cli matic events could affect the mortality of eggs and hatchlings. Our main goal was to assess the effects of extreme climatic events resulting in prolonged precipitation epi sodes on the reproductive output of leatherback turtles Dermochelys coriacea and how these events might reduce hatchling production. To study how short periods of protracted rainfall affect leatherback turtle reproductive output, we recorded (1) the hatching success of n = 48 nests located at 50, 75 and 90 cm depths under sun and shaded treatments from 2013 to 2015 at the Pacuare Reserve in Caribbean coast of Costa Rica, (2) the water table level and (3) sand moisture at 10, 25, 50, 75 and 100 cm depths. In addition, we assessed changes in seasonal precipitation, nest abun dance and the annual hatching success of leatherbacks over time. The results show that prolonged precipitation significantly influenced hatching success. Protracted rain fall increased the water table levels and sand moisture in some places, which conse quently increased egg mortality in deeper nests. These effects may be higher considering the expected increase in storm frequency. Thus, the assessment of the effects of these extreme events on nesting grounds is necessary to predict the poten tial extinction risk of sea turtle populationsUniversidad Nacional, Costa Rica.Instituto Internacional en Conservación y Manejo de Vida Silvestr

Relationship between herkogamy, incompatibility and reciprocity with pollen–ovule ratios in <i>Melochia</i> (Malvaceae)

<p>Heterostyly is a floral polymorphism that increases pollination efficiency by promoting cross-pollination and reducing pollen wastage. Efficiency in pollination has been related to plant investment in gamete production and to the pollen to ovule ratio (P/O), which has been proposed as an indication of the likelihood of enough pollen grains reaching the stigmas to result in maximum reproductive success. In heterostylous species, cross-pollination is promoted by the reciprocal position of sexual organs between morphs and a heteromorphic incompatibility system, which precludes selfing and fertilizations among plants of the same morph. Morphological features like reciprocity (between morphs) and herkogamy (within morph) together with the breeding system are thought to influence pollination quality. Therefore, a close relationship between the pollination efficiency, morphological characteristics, and incompatibility would be expected. Pollination treatments and morphological measurements were carried out to describe the breeding system, herkogamy, and reciprocity of six <i>Melochia</i> species. Afterward, the relation between the P/O (as a surrogate of the efficiency in pollination), and reciprocity, herkogamy and incompatibility was evaluated. Monomorphic <i>M. nodiflora</i> and distylous <i>M. pyramidata</i> are self-compatible species, whereas the rest of the species are self- and morph-incompatible. There was a positive relationship between the P/O value and the degree of herkogamy and incompatibility. However, P/O values appear to increase when higher reciprocity is found in the populations. As expected, the lower values of P/O are associated with lower levels of herkogamy and compatibility in the <i>Melochia</i> species studied. The relationship between the factors is discussed under different scenarios of the pollinators’ predictability.</p

Facilitation allows plant coexistence in Cuban serpentine soils

Serpentine soils represent stressful habitats where plants have to cope with heavy metals, moisture limitation and low nutrient availability. We propose that facilitation is an important mechanism structuring plant communities under such stressful conditions. Facilitation has been shown to generate the spatial association of species, forming discrete vegetation patches of phylogenetically distant species. We measured these spatial and phylogenetic signatures left by facilitation in a serpentine plant community of central Cuba. Our results show that seedlings preferentially grow under plants of different species, and that adults are significantly aggregated into vegetation patches. In these patches, adults tend to co-occur with distant relatives, ultimately forming phylogenetically diverse neighbourhoods. We discuss possible mechanisms explaining how species adapted to serpentine areas may be acting as nurses, reducing the stressful conditions for the establishment of other species. © 2014 German Botanical Society and Royal Botanical Society of the Netherlands.The authors thank all participants on the courses Estructura filogenética de comunidades, developed in Cuba under the CYTED programme (Acción 409AC0369), for fieldwork and discussions. Funding was also provided by AECI (Projects A/016832/08, A017475/08, A023461/09).Peer Reviewe