The efficiency of phenological shifts as an adaptive response against climate change: a case study of loggerhead sea turtles (<Emphasis Type="Italic">Caretta caretta</Emphasis>) in the Mediterranean

Phenological shifts are widely reported for different species as a response to climate change. Still, the efficiency of this mechanism is questioned because of the accelerated rate of change and the different change patterns of various climate parameters that may cause mismatches. Here, using loggerhead sea turtles (Caretta caretta) as model species, we examined whether phenological shifts could be an effective adaptive strategy over the critical period that determines reproductive output in the Mediterranean region. We compared the rate of temperature and precipitation change over the recent past (1971–2015) and future periods (2016–2060) along the 45 main nesting sites of the Mediterranean population, during the incubation period. Next, utilizing predictions of an earlier nesting season, we evaluated whether the timing of incubation will impact offspring survival on the Mediterranean population. To further assess species vulnerability, we investigated any potential relationship between hatching success and climate parameters at the largest Mediterranean nesting rookery (Zakynthos, Greece). We found that phenological changes would allow species to capture a thermal window similar to one they experience nowadays during the incubation period. Still, phenological shifts might be less adequate to follow precipitation changes, which however, were found to have a limited impact upon hatching success. Global adaptation management strategies should be directed towards (a) acquisition of long-term high-resolution temperature and precipitation series at nesting sites, (b) developing early warning systems to prevent negative impacts upon reproductive outputs, and (c) directly applying cooling of the nests when first altered climate signs are detected.     

Are queen Bombus terrestris giant workers or are workers dwarf queens? Solving the 'chicken and egg' problem in a bumblebee species

In the social bee, Bombus terrestris, the two castes differ in size and physiology, but not in any other morphological and anatomical aspects. The size differences between the castes are the result of longer instar duration in prospective queen larvae. It appears that queen larvae are programmed to have a higher molting weight at the end of the 2nd, 3rd and 4th instars. Calculation of the growth ratio, the ratio between the logarithm of molting weight at two successive instars, revealed that queen larvae have a linear growth ratio over the entire larval development as predicted by Dyar's rule. In the worker larvae, in contrast, linearity of the growth ratio breaks after the second instar, resulting in larval molting at lower weights than expected by Dyar's rule. We therefore suggest that workers' development is abnormally shortened, either by parental manipulation or by adopting a different growth plan in response to the queen's signal.     

采用DNA条形码技术对厦门海域鱼卵、仔稚鱼种类的鉴定

以厦门海域采集到的鱼卵、仔稚鱼为研究对象.首先根据形态学特征将其分为2种类型鱼卵和3种类型仔稚鱼,然后应用DNA条形码技术分析鉴定得到3个鱼卵种类和4个仔稚鱼种类.其中,6种鉴定到种的水平,分别为汉氏棱鳀(Thryssa hamiltonii)鱼卵、颈带鲾(Nuchequula nuchalis)鱼卵、纹缟鰕虎鱼(Tridentiger trigonocephalus)仔鱼、髭缟鰕虎鱼(Tridentiger barbatus)仔鱼、斑鰶(Konosirus punctatus)仔鱼和鲬(Platycephalus indicus)稚鱼;1种鉴定到属,即双边鱼属(Ambassis sp.)鱼卵.研究结果表明,将鱼卵、仔稚鱼鉴定到种的水平,绝大多数都需要借助于形态学之外的手段,尤其是形态特征表现相近的鱼卵.而DNA条形码技术采用自动化和标准化应用系统,能有效地对形态特征相似的鱼卵、仔稚鱼进行种类鉴定,具有准确性高、重复性好、人为误差少等优点,已成为传统形态学物种鉴定的强有力补充,在鱼类生物多样性研究中具有广阔的应用前景.     

Run for your life,but bite for your rights? How interactions between natural and sexual selection shape functional morphology across habitats

A central issue in evolutionary biology is how morphology, performance, and habitat use coevolve. If morphological variation is tightly associated with habitat use, then differences in morphology should affect fitness through their effect on performance within specific habitats. In this study, we investigate how evolutionary forces mold morphological traits and performance differently given the surrounding environment, at the intraspecific level. For this purpose, we selected populations of the lizard Podarcis bocagei from two different habitat types, agricultural walls and dunes, which we expected to reflect saxicolous vs ground-dwelling habits. In the laboratory, we recorded morphological traits as well as performance traits by measuring sprint speed, climbing capacity, maneuverability, and bite force. Our results revealed fast-evolving ecomorphological variation among populations of P. bocagei, where a direct association existed between head morphology and bite performance. However, we could not establish links between limb morphology and locomotor performance at the individual level. Lizards from walls were better climbers than those from dunes, suggesting a very fast evolutionary response. Interestingly, a significant interaction between habitat and sex was detected in climbing performance. In addition, lizards from dunes bit harder than those from walls, although sexual differentiation was definitely the main factor driving variation in head functional morphology. Taking into account all the results, we found a complex interaction between natural and sexual selection on whole-organism performance, which are, in some cases, reflected in morphological variation.     

Genetic structure of Mediterranean chukar (Alectoris chukar, Galliformes) populations: conservation and management implications

The chukar (Alectoris chukar, Galliformes) is a species hunted throughout its native range from the East Mediterranean to Manchuria and in the USA, which hosts the world’s largest introduced population. This study aims to investigate the genetic structure of Mediterranean chukar populations to aid management decisions. We genotyped 143 specimens at two regions of the mitochondrial DNA (mtDNA: cytochrome b, control region) and eight loci of the microsatellite DNA. Samples were collected in northern (Limnos, Lesvos, Chios) and southern (Crete) Aegean islands (Greece) and Cyprus. We also carried out mtDNA-based comparison with chukars (n?=?124) from Asia (16 countries) and the USA (five states). We propose six management units for Mediterranean populations. Given their genetic integrity, Limnos and Cyprus, which host different subspecies, proved to be of primary conservation interest. We found exotic A. chukar mtDNA lineages in Lesvos, Chios and Crete and produced definitive genetic evidence for the Asian origin of the US chukars.     

Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to competition

Non-indigenous species are oftentimes exposed to ecosystems with unfamiliar species, and organisms that exhibit a high degree of phenotypic plasticity may be better able to contend with the novel competitors that they may encounter during range expansion. In this study, differences in morphological plasticity were investigated using young-of-year pumpkinseed sunfish (Lepomis gibbosus) from native North American and non-native European populations. Two Canadian populations, isolated from bluegill sunfish (L. macrochirus) since the last glaciation, and two Spanish populations, isolated from bluegill since their introduction in Europe, were reared in a common environment using artificial enclosures. Fish were subjected to allopatric (without bluegill) or sympatric (with bluegill) conditions, and differences in plasticity were tested through a MANOVA of discriminant function scores. All pumpkinseed populations exhibited dietary shifts towards more benthivorous prey when held with bluegill. Differences between North American and European populations were observed in body dimensions, gill raker length and pelvic fin position. Sympatric treatments induced an increase in body width and a decrease in caudal peduncle length in native fish; non-native fish exhibited longer caudal peduncle lengths when held in sympatry with bluegill. Overall, phenotypic plasticity influenced morphological divergence less than genetic factors, regardless of population. Contrary to predictions, pumpkinseeds from Europe exhibited lower levels of phenotypic plasticity than Canadian populations, suggesting that European pumpkinseeds are more canalized than their North American counterparts.     

Impacts of Global Climate Change on Mediterranean Agrigulture: Current Methodologies and Future Directions. An Introductory Essay

Current trends in Mediterranean agriculture reveal differences between the Northern and Southern Mediterranean countries as related to population growth, land and water use, and food supply and demand. The changes in temperature and precipitation predicted by general circulation models for the Mediterranean region will affect water availability and resource management, critically shaping the patterns of future crop production. Three companion papers analyze in detail future impacts of predicted climate change on wheat (Triticum aestivum L.) and maize (Zea mays L.) production in Spain, Greece, and Egypt, and test farm- level adaptation strategies such as early planting and cultivar change with the aid of dynamic crop models. Strategies to improve the assessment of the potential effects of future climate change on agricultural production are discussed.     

Influence of tree species composition,thinning intensity and climate change on carbon sequestration in Mediterranean mountain forests: a case study using the CO2Fix model

Prediction of future forest carbon (C) stocks as influenced by forest management and climate is a crucial issue in the search for strategies to mitigate and adapt to global change. It is hard to quantify the long-term effect of specific forest practices on C stocks due to the high number of processes affected by forest management. This work aims to quantify how forest management impacts C stocks in Mediterranean mountain forests based on 25 combinations of site index, tree species composition and thinning intensity in three different climate scenarios using the CO2Fix v.3.2 model Masera et al. (Ecol Modell 164:177–199, 2003). The study area is an ecotonal zone located in Central Spain, and the tree species are Scots pine (Pinus sylvestris L.) and Pyrenean oak (Quercus pyrenaica Willd.). Our results show a strong effect of tree species composition and a negligible effect of thinning intensity. Mixed stands have the highest total stand C stocks: 100 % and 15 % more than pure oak and pine stands respectively, and are here suggested as a feasible and effective mitigation option. Climate change induced a net C loss compared to control scenarios, when reduction in tree growth is taken into account. Mixed stands showed the lowest reduction in forest C stocks due to climate change, indicating that mixed stands are also a valid adaptation strategy. Thus converting from pure to mixed forests would enhance C sequestration under both current and future climate conditions.     

Inverse Rensch's rule in a frog with female-biased sexual size dimorphism

Rensch's rule claims that sexual size dimorphism (SSD) increases with body size when males are larger but decreases with body size when males are smaller. Chinese wood frog Rana chensinensis is a medium-sized species with female-biased size dimorphism. Using data on body size and age in 27 populations covering the full known size range of the species, we tested the consistency of allometric relationships between the sexes with Rensch's rule and evaluated the hypothesis that SSD is largely a function of age differences between the sexes. The results showed that level of female-biased SSD increased with increasing mean size, supporting the inverse of Rensch's rule. Moreover, most of the variation in SSD can be explained in terms of differences in age between the sexes in populations.     

Cryptic mammalian species: a new species of whiskered bat (Myotis alcathoe n. sp.) in Europe

The analysis of morphological, behavioural and genetic characters of whiskered bats revealed a new European bat species within the family Vespertilionidae. We describe the morphology, karyology, genetic similarity, ecology and distribution of Myotis alcathoe n. sp. It closely resembles Myotis mystacinus, Myotis brandtii and Myotis ikonnikovi in morphology, but all four species show clear genetic differences in two mitochondrial genes (ND1 and 12S rRNA). Myotis alcathoe n. sp. is the smallest species among the European whiskered bats and uses the highest-frequency echolocation calls of all the European Myotis species. It prefers to hunt in small valleys with deciduous trees and flowing water, which is an endangered habitat. Records from Greece and Hungary indicate a distribution range in south-eastern Europe.     

不同水深梯度对4种挺水植物生长繁殖的影响

选择了水葱（Scirpus validus）、菖蒲（Acorus calamus）、香蒲（Typha orientalis）、茭草（Zizania caduciflora）4种常见的挺水植物,研究了静水条件下不同水深梯度（0cm（对照）、30cm（浅水处理）、60cm（深水处理））对4种挺水植物生长和繁殖的影响.试验结...     

Review of the reticulated python (Python reticulatus Schneider, 1801) with the description of new subspecies from Indonesia

The geographically widespread Python reticulatus, the world's longest snake, has been largely neglected by taxonomists. Dwarfed individuals from Tanahjampea Island, Indonesia, differ strikingly in morphology. Phylogenetic relationships were analyzed using a 345-bp fragment of the cytochrome b gene for 12 specimens from different populations. Both genetic differences and morphological characters distinctly revealed two taxonomic subunits. The island populations of Tanahjampea and Selayar form two monophyletic lineages, supported by high bootstrap values, with distinct differences in color pattern and scalation. We consider these forms to represent two new subspecies. The Tanahjampea form is genetically related to populations of the Sunda Islands and mainland Southeast Asia, whereas the Selayar form is related to populations of Southwest Sulawesi. We conclude that, due to strong directional surface currents in this region, gene flow between Tanahjampea and Selayar is prevented. Sea-level changes during the Pleistocene probably contributed to the isolation of the two taxa described. Aspects of ecology and conservation status are briefly discussed. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0320-4.     

Ontogenetic variation in cold tolerance plasticity in Drosophila: is the Bogert effect bogus?

Ontogenetic variation in plasticity is important to understanding mechanisms and patterns of thermal tolerance variation. The Bogert effect postulates that, to compensate for their inability to behaviourally thermoregulate, less-mobile life stages of ectotherms are expected to show greater plasticity of thermal tolerance than more-mobile life stages. We test this general prediction by comparing plasticity of thermal tolerance (rapid cold-hardening, RCH) between mobile adults and less-mobile larvae of 16 Drosophila species. We find an RCH response in adults of 13 species but only in larvae of four species. Thus, the Bogert effect is not as widespread as expected.     

Modeling potential climate change impacts on the trees of the northeastern United States

We evaluated 134 tree species from the eastern United States for potential response to several scenarios of climate change, and summarized those responses for nine northeastern United States. We modeled and mapped each species individually and show current and potential future distributions for two emission scenarios (A1fi [higher emission] and B1 [lower emission]) and three climate models: the Parallel Climate, the Hadley CM3, and the Geophysical Fluid Dynamics Laboratory model. Climate change could have large impacts on suitable habitat for tree species in this region, especially under a high emissions trajectory. Results indicate that while species with potentially increasing areas of suitable habitat in the Northeastern US substantially outnumber those with decreasing areas of habitat, there are key species that show diminishing habitat area: balsam fir (Abies balsamea), paper birch (Betula papyrifera), red spruce (Picea rubens), bigtooth and quaking aspen (Populus grandidentata and P. tremuloides), and black cherry (Prunus serotina). From these results we identified the top 10 losers and gainers for each US state in the region by scenario and emissions trajectory. By combining individual species importance maps and developing assembly rules for various classes, we created maps of potential forest types for the Northeast showing a general loss of the spruce–fir zone with advancing oak–hickory type. Further data, maps, and analysis can be found at http://www.nrs.fs.fed.us/atlas.     

Effects of irrigation and landscape heterogeneity on butterfly diversity in Mediterranean farmlands

Irrigation effects on biodiversity are poorly known, particularly in Mediterranean agro-ecosystems. In this study we analyzed irrigation effects on butterfly species richness, abundance and diversity as well as on species composition in a farmed landscape under Mediterranean climate. The study area consisted of four contiguous agricultural sub-areas with a decreasing degree of intensification: irrigated, mixed (dry and irrigated), dry and environmentally protected (i.e. Special Protection Area, SPA) dry farmland. Forty one km-transects (ten per sub-area) were searched for butterflies in 2008 and 2009. Contrary to expectations, species richness (alfa, beta and gamma diversity) was highest in both years in the most intensified sub-area (i.e. irrigated) followed by SPA, dry and mixed sub-areas. Landscape characteristics accounted for most of the between-subareas differences in species richness. Species richness was negatively related to mean field size at the landscape level and positively related to the number of trees and large shrubs along transects. Therefore, the higher number of butterfly species recorded in the irrigated farmland could be due to a more complex landscape. In contrast, butterfly abundance was highest in cereal steppes (i.e. dry and SPA sub-areas), with abundance being negatively affected by mean field size. Inter-annual change in butterfly abundance was much sharper in rainfed (i.e. dry and SPA) than in irrigated (i.e. irrigated and mixed) sub-areas. Irrigated farmland may provide more favorable conditions for butterflies by buffering the (year-to-year and summer) drought periods characterising Mediterranean climate. Species composition differed among sub-areas, with differences being partly explained by field size and number of trees and shrubs along transects. Our study suggest an important role of landscape characteristics in boosting butterfly biodiversity in intensively managed irrigated croplands and emphasizes the importance of encouraging studies on farmland butterfly diversity in different (bioclimatic) regions allowing the design of region-specific agri-environmental schemes.     

Morphological distinctness despite large-scale phenotypic plasticity��analysis of wild and pond-bred juveniles of allopatric populations of Tropheus moorii

Cichlids are an excellent model to study explosive speciation and adaptive radiation. Their evolutionary success has been attributed to their ability to undergo rapid morphological changes related to diet, and their particular breeding biology. Relatively minor changes in morphology allow for exploitation of novel food resources. The importance of phenotypic plasticity and genetically based differences for diversification was long recognized, but their relationship and relative magnitude remained unclear. We compared morphology of individuals of four wild populations of the Lake Tanganyika cichlid Tropheus moorii with their pond-raised F(1) offspring. The magnitude of morphological change via phenotypic plasticity between wild and pond-bred F(1) fish exceeds pairwise population differences by a factor of 2.4 (mean Mahalanobis distances). The genetic and environmental effects responsible for among population differentiation in the wild could still be recognized in the pond-bred F(1) fish. All four pond populations showed the same trends in morphological change, mainly in mouth orientation, size and orientation of fins, and thickness of the caudal peduncle. As between population differentiation was lower in the wild than differentiation between pond-raised versus wild fish, we suggest the narrow ecological niche and intense interspecific competition in rock habitats is responsible for consistent shape similarity, even among long-term isolated populations.     

Geographic variations of life history traits and potential trade-offs in different populations of the parasitoid Leptopilina heterotoma

Energy allocation is determined by resource availability and trade-offs among traits, and so organisms have to give some traits priority over others to maximize their fitness according to their environment. In this study, we investigated the geographic variations in life history traits and potential trade-offs in populations of the parasitoid Leptopilina heterotoma (Hymenoptera: Figitidae) originating from the north and the south of the Rh?ne–Sa?ne valley (over a gradient of 300?km, South-East France). We measured a set of traits related to reproduction, maintenance, and mobility using several estimators of each of these main functions determined at different times. We did not find any clear differences between populations from contrasting areas, whereas the southern populations, which were all assumed to be exposed to similar environmental conditions, displayed contrasting patterns of energy allocation. Thus, the most likely explanation seems to be that the evolution of the life history of L. heterotoma is probably shaped by local selective pressures, such as microclimate, microhabitats, or intensity of competition, rather than by regional ecological conditions. Using our study as an example, we discuss the interest of considering several traits and using different ways of measuring them, concluding that multiple measurements should be performed in future studies to ensure the robustness of the results.     

Rheum palaestinum (desert rhubarb), a self-irrigating desert plant

The rare plant Rheum palaestinum (Polygonaceae) is a perennial hemicryptophyte that grows during the rainy winter in desert mountainous areas in Israel and Jordan that receive an average annual rainfall of ca. 75 mm. It produces between one and four large round leaves that are tightly attached to the ground and form large rosettes of up to 1 m². These leaves differ markedly from the typical small leaves of most desert plants. Moreover, they have a unique 3D morphology resembling a scaled-down mountainous area with well-developed steep drainage systems, raising the question which selective agents were involved in their evolution. We propose that the large leaves collect rainwater that then infiltrates the soil surrounding the root. We measured the seasonal course of leaf growth, examined the area of wet soil surrounding the root after actual and simulated rain, and modeled the water harvesting capacity using the plant leaf area and the weekly precipitation. We show that even in the slightest rains, water flows above the veins to the leaf’s base where it irrigates the vertical root. A typical plant harvests more than 4,100 cm³ of water per year, and enjoys a water regime of about 427 mm/year, equivalent to the water supply in a Mediterranean climate. This is the first example of self-irrigation by large leaves in a desert plant, creating a leaf-made mini oasis. All authors contributed equally to this paper.     

Response of the bird cherry-oat aphid (Rhopalosiphum padi) to climate change in relation to its pest status, vectoring potential and function in a crop-vector-virus pathosystem

Global climate change threatens world food production via direct effects on plant growth and alterations to pest and pathogen prevalence and distribution. Complex relationships between host plant, pest, pathogen and environment create uncertainty particularly involving vector-borne diseases. We attempt to improve the understanding of the effects of climate change via a detailed review of one crop-vector-pathogen system.The bird cherry-oat aphid, Rhopalosiphum padi, is a global pest of cereals and vector of yellow dwarf viruses that cause significant crop losses in cereals. R. padi exhibits both sexual and parthenogenetic reproduction, alternating between crops and other host plants. In Australia, only parthenogenesis occurs due to the absence of the primary host, thus the aphid continuously cycles from grasses to cereals, allowing for continuous virus acquisition and transmission.We have reviewed the potential impact of future climate projections on R. padi population dynamics, persistence, abundance, dispersal and migration events as well as the interactions between vector, virus, crop and environment, all of which are critical to the behaviour and development of the vector and its ability to transmit the virus. We identify a number of knowledge gaps that currently limit efforts to determine how this pathosystem will function in a future climate.     

Temperature and parasitism by <Emphasis Type="BoldItalic">Asobara tabida</Emphasis> (Hymenoptera: Braconidae) influence larval pupation behaviour in two <Emphasis Type="BoldItalic">Drosophila</Emphasis> species

In holometabolous insects, pupation site selection behaviour has large consequences for survival. Here, we investigated the combined effects of temperature and parasitism by the parasitoid Asobara tabida on larval pupation behaviour in two of its main Drosophila sp. hosts differing in their climate origin. We found that larvae of Drosophila melanogaster—a species with a (sub)tropical origin—placed at 25°C pupated higher in rearing jars than those placed at 15°C. The opposite pattern was observed for Drosophila subobscura larvae—a species from temperate regions—which pupated lower, i.e. on or near the substrate at 25°C, than those placed at 15°C. When placed at 25°C, parasitized larvae of both species pupated closer to the substrate than unparasitized ones. Moreover, the Drosophila larvae that had been exposed and probably stung by A. tabida, but were not parasitized, pupated lower than the control unparasitized larvae. These results provide new insights of host behaviour manipulation by A. tabida larvae.