Antarctic ecology from genes to ecosystems: the impact of climate change and the importance of scale

Antarctica offers a unique natural laboratory for undertaking fundamental research on the relationship between climate, evolutionary processes and molecular adaptation. The fragmentation of Gondwana and the development of wide-scale glaciation have resulted in major episodes of extinction and vicariance, as well as driving adaptation to an extreme environment. On shorter time-scales, glacial cycles have resulted in shifts in distribution, range fragmentation and allopatric speciation, and the Antarctic Peninsula is currently experiencing among the most rapid climatic warming on the planet. The recent revolution in molecular techniques has provided a suite of innovative and powerful tools to explore the consequences of these changes, and these are now providing novel insights into evolutionary and ecological processes in Antarctica. In addition, the increasing use of remotely sensed data is providing a large-scale view of the system that allows these processes to be set in a wider spatial context. In these two volumes, we collect a wide range of papers exploring these themes, concentrating on recent advances and emphasizing the importance of spatial and temporal scale in understanding ecological and evolutionary processes in Antarctica.     

From intervention to impact: modelling the potential mortality impact achievable by different longlasting, insecticide-treated net delivery strategies

ABSTRACT: BACKGROUND: The current target of universal access to long-lasting, insecticide-treated nets (LLIN) is 80% coverage to reduce malaria deaths by 75% by 2015. So far, campaigns have been the main channel for large-scale delivery of LLINs, however the World Health Organization has recommended that equal priority should be given to delivery via routine antenatal care (ANC) and immunization systems (EPI) to target pregnant women and children from birth. These various channels of LLIN delivery are targeted to children of different ages. Since risk of mortality varies with child age and LLIN effectiveness declines with net age, it was hypothesized that the age at which a child receives a new LLIN, and therefore the delivery channel, is important in optimizing the health impact of a net. METHODS: A simple dynamic mathematical model was developed of delivery and impact of LLINs among children under five years of age and their household members, incorporating data on age-specific malaria death rates, net use by household structure, and net efficacy over time. RESULTS: The presented analysis finds that supplementing a universal mass campaign with extra ANC delivery would achieve a 1.4 times higher mortality reduction than campaign delivery alone, reflecting that children born in the years between campaigns would otherwise have access to old nets or no nets at an age of high risk. The relative advantage of supplementary ANC delivery is still present though smaller if malaria transmission levels are lower or if there is a strong mass effect achieved by mass campaigns. CONCLUSION: These results indicate that LLIN delivery policies must take into account the age of greatest malaria risk. Emphasis should be placed on supporting routine delivery of LLINs to young children as well as campaigns. Lucy C Okell and Lucy Smith Paintain contributed equally.     

Potential impact of climate change on selected agricultural crops in north-eastern Austria

The vulnerability and adaptation of major agricultural crops to various soils in north‐eastern Austria under a changing climate were investigated. The CERES crop model for winter wheat and the CROPGRO model for soybean were validated for the agrometeorological conditions in the selected region. The simulated winter wheat and soybean yields in most cases agreed with the measured data. Several incremental and transient global circulation model (GCM) climate change scenarios were created and used in the study. In these scenarios, annual temperatures in the selected region are expected to rise between 0.9 and 4.8 °C from the 2020s to the 2080s. The results show that warming will decrease the crop‐growing duration of the selected crops. For winter wheat, a gradual increase in air temperature resulted in a yield decrease. Incremental warming, especially in combination with an increase in precipitation, leads to higher soybean yield. A drier climate will reduce soybean yield, especially on soils with low water storage capacity. All transient GCM climate change scenarios for the 21st century, including the adjustment for only air temperature, precipitation and solar radiation, projected reductions of winter wheat yield. However, when the direct effect of increased levels of CO₂ concentration was assumed, all GCM climate change scenarios projected an increase in winter wheat yield in the region. The increase in simulated soybean yield for the 21st century was primarily because of the positive impact of warming and especially of the beneficial influence of the direct CO₂ effect. Changes in climate variability were found to affect winter wheat and soybean yield in various ways. Results from the adaptation assessments suggest that changes in sowing date, winter wheat and soybean cultivar selection could significantly affect crop production in the 21st century.     

Changes of China agricultural climate resources under the background of climate change: IX. Spatiotemporal change characteristics of China agricultural climate resources

Based on the 1961-2007 ground surface meteorological data from 558 meteorological stations in China, this paper analyzed the differences of agricultural climate resources in China different regions, and compared the change characteristics of the agricultural climate resources in 1961-1980 (period I) and 1981-2007 (period II), taking the year 1981 as the time node. As compared with period I, the mean annual temperature in China in period II increased by 0.6 degrees C, and the > or = 0 degrees C active accumulated temperature in the growth periods of chimonophilous crops and the > or = 10 degrees C active accumulated temperature in the growth periods of thermophilic crops increased averagely by 123.3 degrees C x d and 125.9 degrees C x d, respectively. In 1961-2007, the mean annual temperature increased most in Northeast China, and the > or = 10 degrees C active accumulated temperature in the growth periods of thermophilic crops increased most in South China. The whole year sunshine hours and the sunshine hours in the growth periods of chimonophilous crops and of thermophilic crops in period II decreased by 125.7 h, 32.2 h, and 53.6 h, respectively, compared with those in period I. In 1961-2007, the annual sunshine hours decreased most in the middle and lower reaches of Yangtze River, while the sunshine hours in the growth periods of chimonophilous crops and of thermophilic crops decreased most in North China and South China, respectively. In the whole year and in the growth periods of chimonophilous and thermophilic crops, both the precipitation and the reference crop evapotranspiration in this country all showed a decreasing trend, with the largest decrement in the precipitation in the whole year and in the growth periods of chimonophilous and thermophilic crops in North China, the largest decrement in the reference crop evapotranspiration in the whole year and in the growth periods of thermophilic crops in the middle and lower reaches of Yangtze River, and the largest decrement in the reference crop evapotranspiration in the growth periods of chimonophilous crops in Northwest China. In 1961-2007, the climate in China in the whole year and in the growth periods of thermophilic crops showed an overall tendency of warm and dry, and the climate in the growth periods of thermophilic crops became warm and dry in Southwest China, North China, and Northeast China, but warm and wet in the middle and lower reaches of Yangtze River, Northwest China, and South China, whereas the climate in the growth periods of chimonophilous crops became warm and dry in North China, but became warm and wet in Northwest China.     

长白山红松年轮细胞尺度参数对气候要素的响应

基于长白山低海拔区的红松年轮样本,建立树轮宽度和细胞尺度参数的7个标准年表;选取部分树轮年表与东岗气象站1959-2007年前一年9月到当年9月的月均气温、月均最高气温、月均最低气温、月降水量进行相关分析;并分析1988年气候突变前后红松年轮指数年表与气候要素的关系,结果表明:所建立的7个标准年表中,细胞个数与轮宽年表的相关性最好;降水和气温都是长白山低海拔区红松树木生长的限制因子,但树轮与降水的相关关系略好于气温,主要表现为与前一年9月和当年5、6月降水的相关达显著水平.细胞大小比轮宽能反映出更多气候信息,主要体现在细胞大小年表与当年3月气温和5月降水呈正相关关系,与当年5月气温呈负相关关系;1988年气温发生升高突变后,树轮对气候要素的响应发生了变化,主要表现为细胞大小对气候要素响应的敏感性降低,与气候要素相关的月份有所提前.     

From databases to modelling of functional pathways

This short review comments on current informatics resources and methodologies in the study of functional pathways in cell biology. It highlights recent achievements in unveiling the structural design of protein and gene networks and discusses current approaches to model and simulate the dynamics of regulatory pathways in the cell.     

Assessment of impact of climate change on Rhododendrons in Sikkim Himalayas using Maxent modelling: limitations and challenges

Integration of climate change aspects in biodiversity management is one the fundamental requirements for long term biodiversity conservation. The explicit modelling of the biodiversity in response to climate change is the primary requirement for making any adaptation strategy. With Himalayan ecosystem in mind and Rhododendron as the species of concern, the current paper models the biogeography of the genera Rhododendron which are found intermixed in their spatial distribution in Sikkim Himalayas, mainly tree varieties, in response to climate change. The modelling algorithm used in the paper is Maxent (maximum entropy) which has estimated the target probability distribution by finding the probability distribution of Maxent. After projection of modelled bioclimatic layers to future climate scenario of SRES-A1B in Maxent, it was found that the suitable bioclimatic envelope for Rhododendron has shrunk considerably under the envisaged climate change scenario. The results on extent and locations of Rhododendron distributions in both the current and future climate scenarios provide a deep insight to the conservation planners about the kind of strategy that needs to be adopted for conserving Rhododendrons in the face of climate change. The challenges observed while doing this analysis highlight the gaps and set the agenda for further research to make the predictions of climate change driven impact on biodiversity scientifically more robust.     

Optimal configurations of spatial scale for grid cell firing under noise and uncertainty

We examined the accuracy with which the location of an agent moving within an environment could be decoded from the simulated firing of systems of grid cells. Grid cells were modelled with Poisson spiking dynamics and organized into multiple ‘modules’ of cells, with firing patterns of similar spatial scale within modules and a wide range of spatial scales across modules. The number of grid cells per module, the spatial scaling factor between modules and the size of the environment were varied. Errors in decoded location can take two forms: small errors of precision and larger errors resulting from ambiguity in decoding periodic firing patterns. With enough cells per module (e.g. eight modules of 100 cells each) grid systems are highly robust to ambiguity errors, even over ranges much larger than the largest grid scale (e.g. over a 500 m range when the maximum grid scale is 264 cm). Results did not depend strongly on the precise organization of scales across modules (geometric, co-prime or random). However, independent spatial noise across modules, which would occur if modules receive independent spatial inputs and might increase with spatial uncertainty, dramatically degrades the performance of the grid system. This effect of spatial uncertainty can be mitigated by uniform expansion of grid scales. Thus, in the realistic regimes simulated here, the optimal overall scale for a grid system represents a trade-off between minimizing spatial uncertainty (requiring large scales) and maximizing precision (requiring small scales). Within this view, the temporary expansion of grid scales observed in novel environments may be an optimal response to increased spatial uncertainty induced by the unfamiliarity of the available spatial cues.     

From climate change predictions to actions – conserving vulnerable animal groups in hotspots at a regional scale

Current climate change is a major threat to biodiversity. Species unable to adapt or move will face local or global extinction and this is more likely to happen to species with narrow climatic and habitat requirements and limited dispersal abilities, such as amphibians and reptiles. Biodiversity losses are likely to be greatest in global biodiversity hotspots where climate change is fast, such as the Iberian Peninsula. Here we assess the impact of climate change on 37 endemic and nearly endemic herptiles of the Iberian Peninsula by predicting species distributions for three different times into the future (2020, 2050 and 2080) using an ensemble of bioclimatic models and different combinations of species dispersal ability, emission levels and global circulation models. Our results show that species with Atlantic affinities that occur mainly in the North‐western Iberian Peninsula have severely reduced future distributions. Up to 13 species may lose their entire potential distribution by 2080. Furthermore, our analysis indicates that the most critical period for the majority of these species will be the next decade. While there is considerable variability between the scenarios, we believe that our results provide a robust relative evaluation of climate change impacts among different species. Future evaluation of the vulnerability of individual species to climate change should account for their adaptive capacity to climate change, including factors such as physiological climate tolerance, geographical range size, local abundance, life cycle, behavioural and phenological adaptability, evolutionary potential and dispersal ability.     

Spatial modelling of nitrous oxide emissions at the national scale using soil, climate and land use information

Nitrous oxide (N₂O) is a powerful greenhouse gas. The UK government is committed to reducing all greenhouse gas emissions and is required to make an inventory of the sources and emissions of these gases. Here, we extend work from a pilot study at the catchment scale reported in an earlier paper. This paper reports on the upscaling measurements of emissions to derive annual emission rates for specific combinations of soil type, land management and fertiliser practices to the national scale. Digital soil, climate and land use maps were combined within Geographic Information Systems (GIS) software. Upscaling of field emissions measurements involves adjusting measured annual N₂O emissions to fit combinations of crop growth cycles, soil wetness and the amount and timing of fertiliser applications. We have also taken account of the differences in emission rates from grazed pasture land due to differences in land management between land utilised for dairy production and land utilised for beef production. Calculated annual emission rates were then spatially scaled to derive national figures through the use of a GIS modelling framework, termed NitOx. The annual emission of N₂O from Scotland was determined as approximately 6 000 000 kg N yr⁻¹ (2.8 Mt carbon dioxide (CO₂) equivalents) and compares favourably with other national scale estimates such as the IPCC (1997) . The combination of animal grazing, high N inputs, climatic warmth and poorly drained soils means that the south west contributes significantly to the national total N₂O emissions. Localised areas of high emission can also be identified, but identification could be improved by applying this modelling approach at a larger scale. It would be beneficial to target these areas with mitigation strategies.     

Comparative modelling of protein structure and its impact on microbial cell factories

Comparative modeling is becoming an increasingly helpful technique in microbial cell factories as the knowledge of the three-dimensional structure of a protein would be an invaluable aid to solve problems on protein production. For this reason, an introduction to comparative modeling is presented, with special emphasis on the basic concepts, opportunities and challenges of protein structure prediction. This review is intended to serve as a guide for the biologist who has no special expertise and who is not involved in the determination of protein structure. Selected applications of comparative modeling in microbial cell factories are outlined, and the role of microbial cell factories in the structural genomics initiative is discussed.     

Development of a Fischer-Tropsch catalyst: From laboratory to commercial scale demonstration

This paper deals with the study, the development and the optimization of a proprietary Fischer-Tropsch process, performed by ENI in cooperation with Institut Fran?ais du Pétrole and Axens, for the transformation of natural gas into liquid fuels. The current carbon scenario and the future forecasts have brought on a renewed interest of the oil companies for this old technology: an overview of the oil and gas reserves underlines the necessity of gas valorisation, and the main GTL projects currently performed around the world are presented. Fischer-Tropsch synthesis details and the catalyst design strategy followed by ENI are also discussed, with specific attention on the problems that are usual met when moving from the laboratory to the industrial and commercial scale.

---

Riassunto   Sviluppo di un catalizzatore Fischer-Tropsch: dalla scala di laboratorio all'impianto dimostrativo in dustriale. Eni, in collaborazione con l'Institut Fran?ais du Pétrole e Axens ha messo a punto un processo Fischer-Tropsch proprietario per la trasformazione di gas naturale in combustibile liquido. L'attuale situazione internazionale e le proiezioni future sull'abbondanza e la disponibilità del petrolio hanno portato ad un rinnovato interesse da parte delle maggiori compagnie petrolifere verso questa ?vecchia? tecnologia. La valutazione delle riserve di olio e di gas mette in evidenza, infatti, la necessità di una valorizzazione del gas naturale e nell'articolo vengono presentati i principali progetti GtL attualmente in fase di realizzazione nel mondo. Viene poi descritta la strategia adottata da Eni/IFP-Axens per lo sviluppo e l'ottimizzazione del catalizzatore e del processo, sottolineando in particolare i problemi che usualmente si incontrano passando dalla scala di laboratorio all'impianto dimostrativo industriale.

     

Population resistance to climate change: modelling the effects of low recruitment in open populations

Isolated populations or those at the edge of their distribution are usually more sensitive to changes in the environment, such as climate change. For the barnacle Semibalanus balanoides (L.), one possible effect of climate change is that unpredictable spring weather could lead to the mismatching of larval release with spring phytoplankton bloom, hence reducing the recruitment. In this paper, model simulations of a variable open population with space limited recruitment were used to investigate the effects of low and zero recruitment on population abundance in S. balanoides. Data for model parameters was taken from an isolated population in the Isle of Man, British Isles. Model simulations with observed frequencies of years with low recruitment showed only small changes in population dynamics. Increased frequencies of low recruitment had large effects on the variation in population growth rate and free space and on population structure. Furthermore, populations with intermediate to high frequencies of low recruitment appeared more sensitive to additional changes in recruitment. Exchanging low recruitment with zero recruitment severely increased the risk of local extinctions. Simulations with consecutive years of low recruitment showed a substantial increase in free space and an increase in the time taken to recover to normal densities. In conclusion, model simulations indicate that variable populations can be well buffered to changes in the demography caused by introduced environmental noise, but also, that intermediate to high frequencies of disturbance can lead to a swift change in population dynamics, which in turn, may affect the dynamics of whole communities.     

气候变化下旱区农业生态系统的可持续性

农业生产是将自然资源不断转化为农产品的过程.简单的说就是将阳光、空气、水和土壤等无机资源转化为可以供人类消费的有机产物.农业生态系统必须对全球气候变化、市场竞争、自然环境的恶化、经济等政策法规和人民的需求等因素做出灵活的应对策略,同时还要保证自然生态系统的稳定性.在发展中国家,有超过20 亿的人口每天收入低于2 美元,他们收入中绝大部分都用于解决温饱.这些人大部分生活在干旱、半干旱地区,并以农业生产作为生活的主要来源.由于这些地区水资源匮乏、土壤贫瘠,粮食安全问题一直是该地区人类生存的关键.中澳两国都把干旱、半干旱地区的农牧业发展作为研究的重点.两国的专家都致力于恢复和维护干旱半干旱地区脆弱的农业生态系统.气候变化正在使农业生态系统可持续发展面临严峻挑战.因此,迫切需要农学,生态学,环境学,社会经济学等多学科的共同发展和融合解决这一问题.     

The plot thickens: New perspectives of primary cell wall modification

Recent studies have further confirmed the ubiquity of cell wall restructuring during plant growth and development, and have emphasized the fact that our understanding of the breadth of molecular processes that mediate wall modification is still rudimentary. In the past few years, both enzymatic and non-enzymatic agents that apparently contribute to wall disassembly have been identified, and it is likely that additional mechanisms will continue to be revealed. These discoveries are being propelled by the development of new biochemical and biophysical assays, by database mining in the wake of the explosion of plant sequence information from genome sequencing and expressed sequence tags, and by a variety of strategies used to catalog the cell wall proteome. The daunting question of how these mechanistically diverse and complex processes are coordinated remains unresolved.     

Determining vulnerability of stream communities to climate change at the landscape scale

1. As the climate changes, species are expected to shift to higher latitudes and altitudes where suitable habitat is available if dispersal is not constrained by geographic barriers. We analyse patterns of turnover in freshwater macroinvertebrate assemblages to identify which communities are most likely to be at risk from climate change, and the location of geographic barriers that could impede such adaptive range shifts. 2. We analysed macroinvertebrate data from standard biological assessments at the family level, from surveys of all coastal basins of New South Wales, Australia, covering a latitudinal gradient of more than 1000 km. We used variance partitioning to separate the variation in composition explained by climate, among‐site distance, human disturbance and other stream factors. 3. Montane stream assemblages showed high turnover in response to climatic variation. Turnover in coastal‐fringe streams was least affected by climate, but strongly correlated with distance and stream variables. Significant shifts in assemblage composition occurred between habitats within catchments and across catchment boundaries. 4. Montane stream assemblages are most vulnerable to climate change because their distribution is most responsive to climatic factors, and elevated sites are isolated from one another, reducing the scope for altitudinal migration. Dispersal limitations in coastal‐fringe assemblages will also increase their vulnerability to habitat loss from sea‐level rise. For all stream classes, the separation of many neighbouring catchment assemblages, owing to either limited dispersal or the lack of suitable habitat, is likely to constrain adaptive range shifts. This would lead to an overall reduction in beta diversity among reaches and subsequently to a reduction in landscape‐level gamma diversity.