Climate Change,Habitat Loss,Protected Areas and the Climate Adaptation Potential of Species in Mediterranean Ecosystems Worldwide

Mediterranean climate is found on five continents and supports five global biodiversity hotspots. Based on combined downscaled results from 23 atmosphere-ocean general circulation models (AOGCMs) for three emissions scenarios, we determined the projected spatial shifts in the mediterranean climate extent (MCE) over the next century. Although most AOGCMs project a moderate expansion in the global MCE, regional impacts are large and uneven. The median AOGCM simulation output for the three emissions scenarios project the MCE at the end of the 21^st century in Chile will range from 129–153% of its current size, while in Australia, it will contract to only 77–49% of its current size losing an area equivalent to over twice the size of Portugal. Only 4% of the land area within the current MCE worldwide is in protected status (compared to a global average of 12% for all biome types), and, depending on the emissions scenario, only 50–60% of these protected areas are likely to be in the future MCE. To exacerbate the climate impact, nearly one third (29–31%) of the land where the MCE is projected to remain stable has already been converted to human use, limiting the size of the potential climate refuges and diminishing the adaptation potential of native biota. High conversion and low protection in projected stable areas make Australia the highest priority region for investment in climate-adaptation strategies to reduce the threat of climate change to the rich biodiversity of the mediterranean biome.     

Climate Change and Health Research in the Eastern Mediterranean Region

Anthropologically induced climate change, caused by an increased concentration of greenhouse gases in the atmosphere, is an emerging threat to human health. Consequences of climate change may affect the prevalence of various diseases and environmental and social maladies that affect population health. In this article, we reviewed the literature on climate change and health in the Eastern Mediterranean Region. This region already faces numerous humanitarian crises, from conflicts to natural hazards and a high burden of disease. Climate change is likely to aggravate these emergencies, necessitating a strengthening of health systems and capacities in the region. However, the existing literature on climate change from the region is sparse and informational gaps stand in the way of regional preparedness and adaptation. Further research is needed to assess climatic changes and related health impacts in the Eastern Mediterranean Region. Such knowledge will allow countries to identify preparedness vulnerabilities, evaluate capacity to adapt to climate change, and develop adaptation strategies to allay the health impacts of climate change.     

Mediterranean Fruit Fly as a Potential Vector of Bacterial Pathogens

The Mediterranean fruit fly (Ceratitis capitata) is a cosmopolitan pest of hundreds of species of commercial and wild fruits. It is considered a major economic pest of commercial fruits in the world. Adult Mediterranean fruit flies feed on all sorts of protein sources, including animal excreta, in order to develop eggs. After reaching sexual maturity and copulating, female flies lay eggs in fruit by puncturing the skin with their ovipositors and injecting batches of eggs into the wounds. In view of the increase in food-borne illnesses associated with consumption of fresh produce and unpasteurized fruit juices, we investigated the potential of Mediterranean fruit fly to serve as a vector for transmission of human pathogens to fruits. Addition of green fluorescent protein (GFP)-tagged Escherichia coli to a Mediterranean fruit fly feeding solution resulted in a dose-dependent increase in the fly's bacterial load. Flies exposed to fecal material enriched with GFP-tagged E. coli were similarly contaminated and were capable of transmitting E. coli to intact apples in a cage model system. Washing contaminated apples with tap water did not eliminate the E. coli. Flies inoculated with E. coli harbored the bacteria for up to 7 days following contamination. Fluorescence microscopy demonstrated that the majority of fluorescent bacteria were confined along the pseudotrachea in the labelum edge of the fly proboscis. Wild flies captured at various geographic locations were found to carry coliforms, and in some cases presumptive identification of E. coli was made. These findings support the hypothesis that the common Mediterranean fruit fly is a potential vector of human pathogens to fruits.     

Seasonal Dynamics of Marine Microbial Community in the South Sea of Korea

High-resolution 16S rRNA tag pyrosequencing was used to obtain seasonal snapshots of the bacterial diversity and community structure at two locations in Gosung Bay (South Sea, Korea) over a one year period. Seasonal sampling from the water column at each site revealed highly diverse bacterial communities containing up to 900 estimated Operational Taxonomic Units (OTUs). The Alphaproteobacteria and Gammaproteobacteria were the most abundant groups, and the most frequently recorded OTUs were members of Pelagibacter and Glaciecola. In particular, it was observed that Arcobacter, a genus of the Epsilonproteobacteria, dominated during summer. In addition, Psedoalteromonadaceae, Vibrionaceae and SAR11-1 were predominant members of the OTUs found in all sampling seasons. Environmental factors significantly influenced the bacterial community structure among season, with the phosphate and nitrate concentrations contributing strongly to the spatial distribution of the Alphaproteobacteria; the Gammaproteobacteria, Flavobacteria, and Actinobacteria all showed marked negative correlations with all measured nutrients, particularly silicon dioxide and chlorophyll-a. The results suggest that seasonal changes in environmental variables contribute to the dynamic structure of the bacterial community in the study area.     

Marine molluscs and fish as biomarkers of pollution stress in littoral regions of the Red Sea, Mediterranean Sea and North Sea

The intensive development of industry and urban structures along the seashores of the world, as well as the immense increase in marine transportation and other activities, has resulted in the deposition of thousands of new chemicals and organic compounds, endangering the existence of organisms and ecosystems. The conventional single biomarker methods used in ecological assessment studies cannot provide an adequate base for environmental health assessment, management and sustainability planning. The present study uses a set of novel biochemical, physiological, cytogenetic and morphological methods to characterize the state of health of selected molluscs and fish along the shores of the German North Sea, as well as the Israeli Mediterranean and Red Sea. The methods include measurement of activity of multixenobiotic resistance-mediated transporter (MXRtr) and the system of active transport of organic anions (SATOA) as indicators of antixenobiotic defence; glutathione S-transferase (GST) activity as an indicator of biotransformation of xenobiotics; DNA unwinding as a marker of genotoxicity; micronucleus test for clastogenicity; levels of phagocytosis for immunotoxicity; cholinesterase (ChE) activity and level of catecholamines as indicators of neurotoxicity; permeability of external epithelia to anionic hydrophilic probe, intralysosomal accumulation of cationic amphiphilic probe and activity of non-specific esterases as indicators of cell/tissue viability. Complete histopathological examination was used for diagnostics of environmental pathology. The obtained data show that the activity of the defensive pumps, MXRtr and SATOA in the studied organisms was significantly higher in the surface epithelia of molluscs from a polluted site than that of the same species from control, unpolluted stations, providing clear evidence of response to stress. Enhanced frequency of DNA lesions (alkaline and acidic DNA unwinding) and micronucleus-containing cells was significantly higher in samples from polluted sites in comparison to those from the clean sites that exhibited genotoxic and clastogenic activity of the pollutants. In all the studied molluscs a negative correlation was found between the MXRtr levels of activity and the frequency of micronucleus-containing hemocytes. The expression of this was in accordance with the level of pollution. The complete histopathological examination demonstrates significantly higher frequencies of pathological alterations in organs of animals from polluted sites. A strong negative correlation was found between the frequency of these alterations and MXRtr activity in the same specimens. In addition to these parameters, a decrease in the viability was noted in molluscs from the polluted sites, but ChE activities remained similar at most sites. The methods applied in our study unmasked numerous early cryptic responses and negative alterations of health in populations of marine biota sampled from the polluted sites. This demonstrates that genotoxic, clastogenic and pathogenic xenobiotics are present and act in the studied sites and this knowledge can provide a reliable base for consideration for sustainable development. Received: 2 March 1999 / Received in revised form: 2 August 1999 / Accepted: 3 August 1999     

Climate Change Threatens Coexistence within Communities of Mediterranean Forested Wetlands

The Mediterranean region is one of the hot spots of climate change. This study aims at understanding what are the conditions sustaining tree diversity in Mediterranean wet forests under future scenarios of altered hydrological regimes. The core of the work is a quantitative, dynamic model describing the coexistence of different Mediterranean tree species, typical of arid or semi-arid wetlands. Two kind of species, i.e. Hygrophilous (drought sensitive, flood resistant) and Non-hygrophilous (drought resistant, flood sensitive), are broadly defined according to the distinct adaptive strategies of trees against water stress of summer drought and winter flooding. We argue that at intermediate levels of water supply the dual role of water (resource and stress) results in the coexistence of the two kind of species. A bifurcation analysis allows us to assess the effects of climate change on the coexistence of the two species in order to highlight the impacts of predicted climate scenarios on tree diversity. Specifically, the model has been applied to Mediterranean coastal swamp forests of Central Italy located at Castelporziano Estate and Circeo National Park. Our results show that there are distinct rainfall thresholds beyond which stable coexistence becomes impossible. Regional climatic projections show that the lower rainfall threshold may be approached or crossed during the XXI century, calling for an urgent adaptation and mitigation response to prevent biodiversity losses.     

Signals of Climate Change in Butterfly Communities in a Mediterranean Protected Area

The European protected-area network will cease to be efficient for biodiversity conservation, particularly in the Mediterranean region, if species are driven out of protected areas by climate warming. Yet, no empirical evidence of how climate change influences ecological communities in Mediterranean nature reserves really exists. Here, we examine long-term (1998–2011/2012) and short-term (2011–2012) changes in the butterfly fauna of Dadia National Park (Greece) by revisiting 21 and 18 transects in 2011 and 2012 respectively, that were initially surveyed in 1998. We evaluate the temperature trend for the study area for a 22-year-period (1990–2012) in which all three butterfly surveys are included. We also assess changes in community composition and species richness in butterfly communities using information on (a) species’ elevational distributions in Greece and (b) Community Temperature Index (calculated from the average temperature of species'' geographical ranges in Europe, weighted by species'' abundance per transect and year). Despite the protected status of Dadia NP and the subsequent stability of land use regimes, we found a marked change in butterfly community composition over a 13 year period, concomitant with an increase of annual average temperature of 0.95°C. Our analysis gave no evidence of significant year-to-year (2011–2012) variability in butterfly community composition, suggesting that the community composition change we recorded is likely the consequence of long-term environmental change, such as climate warming. We observe an increased abundance of low-elevation species whereas species mainly occurring at higher elevations in the region declined. The Community Temperature Index was found to increase in all habitats except agricultural areas. If equivalent changes occur in other protected areas and taxonomic groups across Mediterranean Europe, new conservation options and approaches for increasing species’ resilience may have to be devised.     

Microbial Pathogens in the Fungal Kingdom

The fungal kingdom is vast, spanning ~1.5 to as many as 5 million species diverse as unicellular yeasts, filamentous fungi, mushrooms, lichens, and both plant and animal pathogens. The fungi are closely aligned with animals in one of the six to eight supergroups of eukaryotes, the opisthokonts. The animal and fungal kingdoms last shared a common ancestor ~1 billion years ago, more recently than other groups of eukaryotes. As a consequence of their close evolutionary history and shared cellular machinery with metazoans, fungi are exceptional models for mammalian biology, but prove more difficult to treat in infected animals. The last common ancestor to the fungal/metazoan lineages is thought to have been unicellular, aquatic, and motile with a posterior flagellum, and certain extant species closely resemble this hypothesized ancestor. Species within the fungal kingdom were traditionally assigned to four phyla, including the basal fungi (Chytridiomycota, Zygomycota) and the more recently derived monophyletic lineage, the dikarya (Ascomycota, Basidiomycota). The fungal tree of life project has revealed that the basal lineages are polyphyletic, and thus there are as many as eight to ten fungal phyla. Fungi that infect vertebrates are found in all of the major lineages, and virulence arose multiple times independently. A sobering recent development involves the species Batrachochytrium dendrobatidis from the basal fungal phylum, the Chytridiomycota, which has emerged to cause global amphibian declines and extinctions. Genomics is revolutionizing our view of the fungal kingdom, and genome sequences for zygomycete pathogens (Rhizopus, Mucor), skin-associated fungi (dermatophytes, Malassezia), and the Candida pathogenic species clade promise to provide insights into the origins of virulence. Here we survey the diversity of fungal pathogens and illustrate key principles revealed by genomics involving sexual reproduction and sex determination, loss of conserved pathways in derived fungal lineages that are retained in basal fungi, and shared and divergent virulence strategies of successful human pathogens, including dimorphic and trimorphic transitions in form. The overarching conclusion is that fungal pathogens of animals have arisen repeatedly and independently throughout the fungal tree of life, and while they share general properties, there are also unique features to the virulence strategies of each successful microbial pathogen.     

Response of Microbial Community Composition and Function to Soil Climate Change

Soil microbial communities mediate critical ecosystem carbon and nutrient cycles. How microbial communities will respond to changes in vegetation and climate, however, are not well understood. We reciprocally transplanted soil cores from under oak canopies and adjacent open grasslands in a California oak–grassland ecosystem to determine how microbial communities respond to changes in the soil environment and the potential consequences for the cycling of carbon. Every 3 months for up to 2 years, we monitored microbial community composition using phospholipid fatty acid analysis (PLFA), microbial biomass, respiration rates, microbial enzyme activities, and the activity of microbial groups by quantifying ¹³C uptake from a universal substrate (pyruvate) into PLFA biomarkers. Soil in the open grassland experienced higher maximum temperatures and lower soil water content than soil under the oak canopies. Soil microbial communities in soil under oak canopies were more sensitive to environmental change than those in adjacent soil from the open grassland. Oak canopy soil communities changed rapidly when cores were transplanted into the open grassland soil environment, but grassland soil communities did not change when transplanted into the oak canopy environment. Similarly, microbial biomass, enzyme activities, and microbial respiration decreased when microbial communities were transplanted from the oak canopy soils to the grassland environment, but not when the grassland communities were transplanted to the oak canopy environment. These data support the hypothesis that microbial community composition and function is altered when microbes are exposed to new extremes in environmental conditions; that is, environmental conditions outside of their “life history” envelopes.     

High Contribution of SAR11 to Microbial Activity in the North West Mediterranean Sea

We investigated the abundance and activity of SAR11 on a monthly time scale between January 2008 and October 2008 in the oligotrophic NW Mediterranean Sea. Applying MICRO-CARD-FISH, we observed that SAR11 had a large contribution to bulk abundance (37 ± 6% of DAPI-stained cells) and to bulk bacterial heterotrophic production (BHP), as estimated from leucine incorporation (55 ± 15% of DAPI-cells assimilating leucine) in surface waters (5 m) throughout the study period. SAR11 contributed also substantially to the assimilation of glucose, ATP, and a combination of amino acids (44 ± 17%, 37 ± 14%, and 43 ± 12% of DAPI cells assimilating these compounds, respectively), organic compounds that provide either single or combined sources of C, P, and N. Temporal changes in the abundance of SAR11 cells that assimilated leucine, glucose, amino acids, and ATP revealed a pattern consistent with that of substrate-active DAPI cells, suggesting that the activity of SAR11 can explain to a large extent the variability in total cells contributing to the utilization of these compounds. Short-term nutrient enrichment experiments performed on each sampling date revealed a strong co-limitation of at least two of the three elements analyzed (C, N, P), in particular, during summer and early autumn. The in situ abundance of SAR11 cells assimilating leucine appeared to increase with P limitation as determined in the nutrient enrichment experiments (r = 0.81, p = 0.015). Our results demonstrate that SAR11 is an important component of the active bacterial community in the NW Mediterranean Sea. Our observations further indicate that the activity of the bulk bacterial community is linked to the activity of SAR11, possibly due to its adaptation to nutrient limitation.     

Climate Change Influences on the Global Potential Distribution of Bluetongue Virus

The geographic distribution of arboviruses has received considerable attention after several dramatic emergence events around the world. Bluetongue virus (BTV) is classified among category “A” diseases notifiable to the World Organization of Animal Health (OIE), and is transmitted among ruminants by biting midges of the genus Culicoides. Here, we developed a comprehensive occurrence data set to map the current distribution, estimate the ecological niche, and explore the future potential distribution of BTV globally using ecological niche modeling and based on diverse future climate scenarios from general circulation models (GCMs) for four representative concentration pathways (RCPs). The broad ecological niche and potential geographic distribution of BTV under present-day conditions reflected the disease’s current distribution across the world in tropical, subtropical, and temperate regions. All model predictions were significantly better than random expectations. As a further evaluation of model robustness, we compared our model predictions to 331 independent records from most recent outbreaks from the Food and Agriculture Organization Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases Information System (EMPRES-i); all were successfully anticipated by the BTV model. Finally, we tested ecological niche similarity among possible vectors and BTV, and could not reject hypotheses of niche similarity. Under future-climate conditions, the potential distribution of BTV was predicted to broaden, especially in central Africa, United States, and western Russia.     

气候变化对5种植物分布的潜在影响

利用CART(分类和回归树Classification and regression tree)模型,采用A2和B2气候情景,模拟分析了气候变化对观光木(Tsoongiodendron odorum)、鹅掌楸(Liriodendron chinense)、独叶草(Kingdonia uniflora)、草苁蓉(Boschniakia rossica)和刺五加(Acanthopanax senticosus)分布范围及空间格局的影响。结果表明:与目前适宜分布范围相比,气候发生变化后,观光木的分布范围变化不大,其它植物则缩小;观光木的新适宜与总适宜分布范围扩大,而其它植物缩小;草丛蓉和刺五加的目前适宜、新适宜及总适宜分布范围缩小幅度较大,鹅掌楸和独叶草次之;观光木和鹅掌楸向目前适宜分布区北部区域扩展,独叶草向西南区域扩展,草丛蓉和刺五加的适宜范围在2081～2100年会散失。气候变化下,这些植物的适宜分布范围随年降水量和年均气温的变化不一致,观光木的目前适宜、独叶草的新适宜及总适宜分布范围与年降水量和年均气温,以及草苁蓉的分布范围与降水量的相关性不显著(P0.05)。这些植物的空间分布格局将随气候变化而发生变化。     

Microbial Diversity in the Deep Marine Sediments from the Qiongdongnan Basin in South China Sea

The continental shelf and slope in the northern South China Sea is well known for its prospect of oil/gas/gas-hydrate resources. To study microbial communities and their roles in carbon cycling, a 4.9-m sediment core was collected from the Qiongdongnan Basin on the continental slope of the South China Sea during our cruise HY4-2005-5 in 2005. Geochemical, mineralogical, and molecular phylogenetic analyses were carried out. Sulfate concentration in pore water decreased with depth. Abundant authigenic carbonates and pyrite were observed in the sediments. The bacterial community was dominated by aerobic and facultative organisms. Bacterial clone sequences belonged to the Gamma-, Alpha-, Deltaproteobacteria and Firmicutes group, and they were related to Fe(III) and/or Mn(IV) reducers, sulfate reducers, aromatic hydrocarbon degraders, thiosulfate/sulfite oxidizers, and denitrifiers. Archaeal clone sequences exhibited greater overall diversity than the bacterial clones with most sequences related to Deep-Sea Archaeal Group (DSAG), Miscellaneous Crenarchaeotic Group (MCG), and Uncultured Euryarchaeotic Clusters (UECs). Archaeal sequences related to Methanosarcinales, South African Gold Mine Euryarchaeotic Group (SAGMEG), Marine Benthic Group-D (MBG-D) were also present. Most of these groups are commonly present in deep-sea sediments, particularly in methane/organic-rich or putative methane hydrate-bearing sediments.     

Effects of Climate Change on the Potential Species Richness of Mesoamerican Forests

The realized species richness of tropical forests cannot yet be reliably mapped at a regional scale due to lack of systematically collected data. An estimate of the potential species richness (PSR), however, can be produced through the use of species distribution modelling. PSR is interpretable as a climatically determined upper limit to observed species richness. We mapped current PSR and future PSR under climate change scenarios for Mesoamerica by combining the spatial distributions of 2000 tree species as predicted by generalized additive models built from herbaria records and climate layers. An explanatory regression tree was used to extract conditional rules describing the relationship between PSR and climate. The results were summarized by country, ecoregion and protected area status in order to investigate current and possible future variability in PSR in the context of regional biodiversity conservation. Length of the dry season was found to be the key determinant of PSR. Protected areas were found to have higher median PSR values than unprotected areas in most of the countries within the study area. Areas with exceptionally high PSR, however, remain unprotected throughout the region. Neither changes in realized species richness nor extinctions will necessarily follow changes in modelled PSR under climate change. However model output suggests that an increase in temperature of around 3°C, combined with a 20 percent decrease in rainfall could lead to a widespread reduction of around 15 percent of current PSR, with values of up to 40 percent in some moist lower montane tropical forests. The modelled PSR of dry forest ecoregions was found to be relatively stable. Some cooler upper montane forests in northern Mesoamerica, where few species of tropical origin are currently found, may gain PSR if species are free to migrate.