Seasonal Climatic Fluctuations Research Articles

Variability for a day or a season

Physiological Ecology Species that experience larger seasonal climatic fluctuations are likely to be more physiologically flexible and thus likely to occur across a wider elevational range. Daily changes in temperature are also common but have rarely been considered. Chan et al. used a global data set of vertebrates to look at how these two different sets of variation affect a species' elevational distribution (see the Perspective by Perez et al. ). Unexpectedly, larger daily fluctuations were associated with smaller elevational distributions. Thus, specialists are favored where daily fluctuations are dominant, whereas generalists are favored where seasonal fluctuations are the main climate influence. Science , this issue p. [1437][1]; see also p. [1392][2] [1]: /lookup/doi/10.1126/science.aab4119 [2]: /lookup/doi/10.1126/science.aaf3343

Changes of Dry Matter, Biomass and Relative Growth Rate with Different Phenological Stages of Corn

Abstract Crop growth period and the length of the phenological stages on plant are directly affected by climate condition. Therefore, seasonal climate fluctuations such as maximum and minimum daily temperature changing and precipitation rates are important for quantity of annual corn production in Mediterranean area. This study was carried out to determination of dry matter, biomass, relative growth rate (RGR) values in eleven phenological stages [4 leaf (V4), 8 leaf (V8), 12 leaf (V12), 16 leaf (V16), tasseling (VT), silking (R1), blister (R2), milk (R3), dough (R4), dent (R5) and maturity (R6)] of corn during the period 2005, 2006 and 2007 in Aydin location, which is characteristically Mediterranean weather condition in Turkey. Additionally, calculated growing degree days (GDD), per ear weight, plant and ear height (cm), blank tip of ear (shriveled remnants of kernels because of ineffective pollination) (cm) were measured throughout the phenological stages. The data of the study is average of 31G98 and 32K61 corn hybrids value. It is seeming that a significantly differences amongst the years which the field study establishment. All properties except to per ear weight were significantly affected to years. Maximum dry matter and biomass values on the phenological stages were measured in 2005. Maximum per ear weight, plant and ear height values were also obtained from the first year of the experiment. However maximum blank tip of ear value was obtained from 2007. It is suggested that three parameters should be used for yield estimating and determination of biomass and dry matter values among phenological stages of corn. These parameters are: (i) calculating GDD values, (ii) rainfall amounts and air humidity of the years and (iii) determining the number of days when daily temperature rises above 37.5 o C during growth in stages of corn.

Agricultural and forested land use impacts on floodplain shallow groundwater temperature regime

AbstractGiven the importance of groundwater temperature to the biogeochemical health of aquatic ecosystems, a floodplain study was implemented to improve understanding of rural land use impacts on shallow groundwater (SGW) temperature. Study sites included a historic agricultural field (Ag) and bottomland hardwood forest (BHF), each with nine piezometers in an 80 × 80 m grid. Piezometers were equipped with pressure transducers to monitor SGW temperature and level at 30 min intervals during the 2011, 2012, 2013, and 2014 water years. The study is one of the first to utilize long‐term, continuous, automated, in situ monitoring to investigate rural land use impacts on shallow groundwater temperatures. Average SGW temperature during the study period was 11.1 and 11.2 °C at the Ag and BHF sites, respectively. However, temperature range at the Ag site was 72% greater than at the BHF site. Results indicate a greater responsiveness to seasonal climate fluctuations in Ag site SGW temperature related to absence of forest canopy. Patterns of intra‐site groundwater temperature differences at both study sites illustrate the influence of stream–aquifer thermal conduction and occasional baseflow reversals. Considering similar surface soil temperature amplitudes and low average groundwater flow values at both sites, results suggest that contrasting rates of plant water use, groundwater recharge, and subsurface hydraulic conductivity are likely mechanistic causes for the observed SGW temperature differences. Results highlight the long‐term impact of forest removal on subsurface hydrology and groundwater temperature regime. Copyright © 2015 John Wiley & Sons, Ltd.

Does Market Access Protect Children against Poor Health Conditions at Birth?

Seasonal fluctuations in early life circumstances can be associated with later differences in health outcomes, especially for children in rural farm households and in low‐income countries. Other evidence finds that access to markets and public services can help rural households improve their well‐being. This study links these two phenomena, using spatial diversity across the Democratic Republic of Congo (DRC) to investigate whether proximity to towns confers resilience against seasonal determinants of maternal and infant health. To identify a potentially causal effect, we use the random component of birth timing relative to the intensity of seasonal climate fluctuations and households' distance to the nearest town. This approach is made possible by systematic variation in the intensity and duration of seasons from north to south across DRC, independent variation in geographic isolation among survey sites, and uniform distribution in birth timing within years. Controlling for mother fixed effects and a variety of robustness tests, we find that that children in households closer to towns have significantly smaller impact of their birth timing on their subsequent heights and risk of death. The protective effect of market access could involve a variety of mechanisms such as consumption smoothing, health services and public assistance. Future work might find ways to distinguish among these channels using additional data. For this initial study, we merged geocoded Demographic and Health Survey (DHS) results with geo‐coded data on civil conflict and the locations of towns, providing an unusual opportunity to identify the consequences of geographic isolation for child health. This work was supported by a U.S. Borlaug Fellowship in Global Food Security.

Abundance, biomass and diversity of ground-beetles (Col. Carabidae) as indicators of climatic change effects over elevation strata in Tenerife (Canary Islands)

Species relative importance distribution pattern changes of the ground-beetle assemblages were analyzed along elevation strata of Tenerife Island. The species importance estimates were expressed in terms of (i) activity density, as total catching of ground-beetle adults obtained with pitfall traps over each elevation stratum for one year, and (ii) biomass, as the total number of specimens caught multiplied by a mean dry weight in milligrams for the species. The K-dominance curves indicated moderate or insignificant perturbances, and patterns were sigmoidal following a truncated log-normal slightly skewed to the right, by using the Kolmogoroff–Smirnov test. The results also showed perceptible deviations from the truncated log-normal pattern (p<0.05) mainly with biomass data. The disturbance through successional progress and perturbances by environmental warming and cooling could be assumed by deviations from the log-normal distribution among species. Thus, assuming that the assemblages of strata exhibited generally low similarity, the results will be arranged around the following four tracks: (1) the assemblage progressed toward highest abundances, dominance and a low-diversity equilibrium state in the cloud montane stratum, (2) the assemblage was subject to severe warming and dryness, lowest abundances with dominance in biomass, such that log-normal pattern was not shown in the basal stratum, (3) a non-equilibrium state in summer-xeric montane stratum maintained the highest diversity and an archetypical log-normal pattern was described for assemblage, and (4) assemblage stressed by cold semi-arid climate showed a certain tendency to log-normality and decrease in the diversity for the summit stratum. These results indicate that variation in ground-beetle assemblages by way of advanced evolutionary and adaptive trade-offs can best be understood as consequences of selective pressures by adverse climatic changes – perturbances – or seasonal climatic fluctuations and population dynamics – disturbances – according to the elevation stratum, which can generate different deviations from the log-normal pattern; these are more directly related to magnitude and frequency of local natural disturbance regimes and the productivity of the ecosystem.

Floodplain ecohydrology: Climatic, anthropogenic, and local physical controls on partitioning of water sources to riparian trees.

Seasonal and annual partitioning of water within river floodplains has important implications for ecohydrologic links between the water cycle and tree growth. Climatic and hydrologic shifts alter water distribution between floodplain storage reservoirs (e.g., vadose, phreatic), affecting water availability to tree roots. Water partitioning is also dependent on the physical conditions that control tree rooting depth (e.g., gravel layers that impede root growth), the sources of contributing water, the rate of water drainage, and water residence times within particular storage reservoirs. We employ instrumental climate records alongside oxygen isotopes within tree rings and regional source waters, as well as topographic data and soil depth measurements, to infer the water sources used over several decades by two co-occurring tree species within a riparian floodplain along the Rhône River in France. We find that water partitioning to riparian trees is influenced by annual (wet versus dry years) and seasonal (spring snowmelt versus spring rainfall) fluctuations in climate. This influence depends strongly on local (tree level) conditions including floodplain surface elevation and subsurface gravel layer elevation. The latter represents the upper limit of the phreatic zone and therefore controls access to shallow groundwater. The difference between them, the thickness of the vadose zone, controls total soil moisture retention capacity. These factors thus modulate the climatic influence on tree ring isotopes. Additionally, we identified growth signatures and tree ring isotope changes associated with recent restoration of minimum streamflows in the Rhône, which made new phreatic water sources available to some trees in otherwise dry years.Key PointsWater shifts due to climatic fluctuations between floodplain storage reservoirsAnthropogenic changes to hydrology directly impact water available to treesEcohydrologic approaches to integration of hydrology afford new possibilities

Drivers of home range characteristics across spatiotemporal scales in a Neotropical primate, Cebus capucinus

The factors that drive within-species variation in animal space use remain poorly understood. A growing body of evidence suggests that both home range attributes and biological interpretations of the home range may depend fundamentally on the scale of analysis. We utilize a multiscale mixed effects modelling framework to examine how seasonal fluctuations in climate, food resource abundance and group mass affect variance in home range area and the maturity stage of forest used by a group-living Neotropical primate, the white-faced capuchin, Cebus capucinus. Using an 8-year data set representing over 20 000 contact hours, we estimated home ranges for seven social groups at four nested temporal scales and three nested spatial scales using a movement-based kernel method. Group mass was consistently the most important predictor of home range size in our models, and its effects were relatively insensitive to spatial or temporal scale. Mean daily maximum temperature was an influential factor in shaping monthly range area and composition, with hotter weather favouring smaller home range size and increased use of mature evergreen forest. Greater fruit availability was also associated with smaller monthly range area. The effects of temperature and fruit availability were both scale dependent: the impact of both variables was greatest on the core zone. The different study groups showed marked variation in the habitat composition of their home ranges, but in all groups, higher-use zones consisted of older, more evergreen forest. Our study illustrates the complex ecological processes that affect movement behaviour in a Neotropical primate across a range of spatial and temporal scales, highlighting the importance of group mass, climatic seasonality, landscape heterogeneity and dietary shifts in shaping the home range.

Sulfur, iron and carbon cycling following hydrological restoration of acidic freshwater wetlands

Freshwater re-flooding is a relatively novel approach to remediate drained acid sulfate soil (ASS) wetlands. This study documents the geochemical consequences of restoring freshwater re-flooding for contemporary reduced inorganic sulfur (RIS) and iron species in two coastal floodplain ASS wetlands. Re-flooding has established predominantly reducing/suboxic conditions and encouraged organic carbon accumulation in surface sediments (~20–30%). The pH of former sulfuric horizons has increased by ~2–3 units, partly in response to alkalinity generation from anaerobic metabolism of organic carbon coupled with Fe(III) and SO42− reduction. Despite considerable sulfidisation, reactive Fe (FeR; sum of 1M HCl and citrate–dithionite extracts) and non-sulfidic Fe(II) remain abundant in both wetlands. High concentrations of Fe2+ (up to ~5mM) in wetland porewaters represent a considerable pool of labile net acidity and is partly a result of insufficient S(−II) to sequester excess Fe2+. Accumulation of iron sulfides appears to be constrained more by SO42− and carbon availability rather than FeR. Reformation and accumulation of RIS species is greatest in organic-rich surface horizons (~40–500μmolg−1), where time integrated RIS accumulation rates approximate 10–100nmolg−1 d−1. While pyrite is the dominant RIS species to have formed since re-flooding, there is anomalous accumulation of S(0) (up to 80μmolg−1), accounting for ~50% of the RIS pool in some samples. Greigite (Fe3S4) has formed in near-surface sediments and while AVS-S is a minor component of the RIS pool overall, at some locations maximum concentrations exceed 300μmolg−1. Contemporary near-surface pyrite is characterised by abundant small (200–300nm) crystals, in contrast to relic sedimentary pyrite of estuarine origin that is dominated by larger crystals with diverse habit. Although Fe and SO42− reduction are partly responsible for wetland-scale recovery from acute acidification, the resultant accumulation of diverse RIS species in surficial sediments indicates an oxidative component to the S-cycle and represents a hysteresis in S-cycling that contrasts markedly with the drained conditions existing before remediation. Analysis of seasonal climate fluctuations suggests that near-surface sediments containing contemporary RIS are vulnerable to oxidation and possible temporary re-acidification during future drought episodes. This study underscores the long-term legacy of ASS wetland drainage and highlights the need for both considered hydrological management of re-flooded wetlands and further study to quantify possible re-acidification risks associated with seasonal drought.

SEASONAL FLUCTUATIONS AND ECONOMIC GROWTH

The industrial revolution and the subsequent industrialization of the economies occurred first in temperate regions. We argue that this and the associated positive correlation between absolute latitude and GDP per capita are due to the fact that countries located far from the equator suffered more profound seasonal fluctuations in climate, namely stronger and longer winters. We propose a growth model of biased innovations that accounts for these facts and show that countries located in temperate regions were more likely to create or adopt capital-intensive modes of production.The intuition behind this result is that savings are used to smooth consumption; therefore, in places where output fluctuations are more profound, savings are bigger. Because the incentives to innovate depend on the relative supply factors, economies where savings are bigger are more likely to create or adopt capital-intensive technologies.Keywords: Absolute Latitude, Seasons, Endogenous Growth, Capital Using InnovationsJEL classification: N00, O00, O11, O31, O33(ProQuest: ... denotes formulae omitted.)1. INTRODUCTIONThe industrial revolution occurred first in temperate regions and, since then, the world has experienced a massive absolute divergence in the distribution of incomes across countries. Indeed, today there is a positive correlation between absolute latitude and GDP per capita. Moreover, only three tropical economies (Hong Kong, Singapore, and Taiwan) are classified as high-income by the World Bank, while all countries within regions zoned as temperate had either middle or high-income economies.We argue that climatic conditions affect incentives to save in primitive economies in such a way that economies located in temperate regions are more likely to become capital abundant. In primitive economies the main source of output fluctuations is climatic and these are bigger in places located far away from the equator. Indeed, both the harvest per year and the diversification of crops are higher in tropical countries (see Chang, 1997). During the frost days in winter there is no harvest, transportation is difficult, people need more energy and, in general, surviving demands much more work. The response of people to these natural forces is saving during the good days to make bad days better. The stronger the winter the higher the level of savings needed to survive during the frost days. Finally, economies where the savings are systematically bigger are more likely to both, create and adopt capital intensive technologies. Once an economy begins to use capital intensive technologies a process of capital accumulation and capital improvement starts. Capital abundance generates the incentives for capital-using innovations and capital-using technologies generate the incentives for capital accumulation.Many endogenous growth models predict poverty traps, that is, depending on the initial abundance of capital economies can present long run growth or be trapped in a steady state with no economic growth.1 In particular, according to the literature of biased technological change the incentives to innovate depend on the relative supply of factors: in capital abundant economies individuals have incentives to make capital-using innovations while in economies where capital is scarce there are no incentives for this type of innovation.2 These innovations increase the elasticity of output with respect to capital as well as the incentives to save, so a virtuous circle derives capital abundant economies to long-run growth. Models of factor saving innovations generally predict that both the elasticity of output with respect to capital and the capital income share must be higher in richer economies. However, in general these models do not try to explain differences in initial conditions. Among these lines, Peretto and Seater (2006) present a model where the saving rate is exogenous and prove that differences in this variable can explain long run income differences. …

Seasonal fluctuations of resource abundance and avian feeding guilds across forest–farmland boundaries in tropical Africa

Seasonal fluctuations in climatic factors are expected to increase in future decades. However, little is known about the response of tropical species communities to seasonal fluctuations in climate and resource availability, particularly across different habitat types. We examined the relationship between spatio‐temporal fluctuations in the abundance of fruits and invertebrates and two avian feeding guilds, i.e. frugivores and insectivores, in forest and farmland habitats in western Kenya. Fruits and invertebrates fluctuated substantially throughout the year, but seasonal fluctuations were asynchronous between the two habitat types. Species richness and total abundance of frugivores and insectivores also fluctuated strongly and were closely related to the abundance of their respective resources. Frugivore species richness fluctuated anti‐cyclical in forest and farmland habitats, suggesting that several frugivorous species tracked fruit resources across habitat boundaries. In contrast, insectivorous bird richness fluctuated synchronously in the two habitat types, suggesting a lack of local‐scale movements across habitat boundaries. We conclude that bird communities strongly respond to seasonal fluctuations in resource availability, but responses differ between feeding guilds. While frugivores seem to respond flexibly to seasonal fluctuations, for instance by tracking fruit resources across habitat boundaries, insectivorous birds appear to be more susceptible to the expected increase in seasonal fluctuations in resource availability.

Assessing the biological control potential of an adventitiously-established “pest”, Scirtothrips aurantii (Faure), on a weed, Bryophyllum delagoense (Eckl. & Zeyh.), in Queensland

South African citrus thrips ( Scirtothrips aurantii) established adventitiously in Australia. Although it is a major horticultural pest in Africa, it is now advocated as a possible biological control agent against Bryophyllum delagoense Eckl. & Zeyh. (Crassulaceae). To evaluate the biocontrol potential of S. aurantii a two year field study was conducted on the western Darling Downs of southern Queensland. Imidacloprid insecticide was applied to two quadrats at each of 18 field sites to assess, in the absence of S. aurantii, the persistence of individual plants and to quantify propagule production and recruitment by this declared weed. A third quadrat was left, as a control, to be infested naturally by S. aurantii. When released from herbivory by thrips in the field, plants grew significantly more, flowered more, and were significantly more fecund than plants in the quadrats with S. aurantii. Increases in growth and fecundity translated into significantly increased plant numbers but not increased recruitment. Recruitment even declined in experimental quadrats, through the indirect effects of releasing plants from herbivory. Field sampling also revealed that S. aurantii may be sensitive to seasonal climatic fluctuations. These and other local climatic influences may limit the biological control potential of the insect.

Large Greenhouse Gas Emissions from a Temperate Peatland Pasture

Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH4 emissions reduced in favor of greater CO2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on N2O or global warming potential. We report greenhouse gas fluxes (CH4, CO2, N2O) from a drained peatland in the Sacramento-San Joaquin River Delta, California, USA currently managed as a rangeland (that is, pasture). This ecosystem was a net source of CH4 (25.8 ± 1.4 mg CH4-C m−2 d−1) and N2O (6.4 ± 0.4 mg N2O-N m−2 d−1). Methane fluxes were comparable to those of other managed temperate peatlands, whereas N2O fluxes were very high; equivalent to fluxes from heavily fertilized agroecosystems and tropical forests. Ecosystem scale CH4 fluxes were driven by “hotspots” (drainage ditches) that accounted for less than 5% of the land area but more than 84% of emissions. Methane fluxes were unresponsive to seasonal fluctuations in climate and showed minimal temporal variability. Nitrous oxide fluxes were more homogeneously distributed throughout the landscape and responded to fluctuations in environmental variables, especially soil moisture. Elevated CH4 and N2O fluxes contributed to a high overall ecosystem global warming potential (531 g CO2-C equivalents m−2 y−1), with non-CO2 trace gas fluxes offsetting the atmospheric “cooling” effects of photoassimilation. These data suggest that managed Delta peatlands are potentially large regional sources of greenhouse gases, with spatial heterogeneity in soil moisture modulating the relative importance of each gas for ecosystem global warming potential.

Diversity and ecology of algae in the Algeti National Park as a part of the Georgian system of protected areas

Algal communities from the Algeti National Park in eastern Georgia were studied between 2005 and 2008. The algal species diversity comes from 77 algological samples and includes 315 species and infraspecies, which belong to 7 taxonomical divisions. Of these findings, 295 species are reported for the first time in the Algeti National Park and 9 of them are new for Georgia. The most abundant are diatoms, with 220 species. Communities were dominated by Cladophora glomerata (L.) Kütz. (Chlorophyta), Spirogyra sp. (Charophyta), Ulnaria ulna (Nitzsch) Compère (diatom), and Phormidium autumnale (C.Agardh) R.Trevis. ex Gomont (Cyanobacteria). The index of species diversity per area in the Algeti is 6.89. The comparative floristic and statistical analysis of algal communities from Algeti and 13 other Georgian Natural Reserves, altogether 1063 species, divides the communities into groups of less than or more than 200 species, with diatom or nondiatom domination that correlates with climatic variables. The species diversity in the natural reserves increases from the Black Sea coast to the east, a movement that corresponds to a similar increase in altitude. In this study, 3 floristic groups are recognized: mountainous areas, lowlands, and piedmonts. The most species-rich communities are found in extreme environments. A correlation of algal diversity with environmental conditions shows that the altitude-dependent regional climatic variables and the lowest winter air temperature in particular, are the major factors. The index of infraspecies variation in each reserve is a small range (1.01-1.15) and shown to be a result of constant altitude combined with seasonal climatic fluctuations. The diversity indices and bioindication analysis reflect a moderate level of anthropogenic disturbance for the protected areas.

Intra-tooth oxygen isotope variation in a known population of red deer: Implications for past climate and seasonality reconstructions

Over the last decade oxygen isotopes from herbivore teeth have frequently been used as a proxy for palaeoclimatic conditions, yet our knowledge of how accurately the isotope signatures of an animal reflect seasonal climatic fluctuations remains limited. Our study on modern red deer from a known location aimed to assess the degree to which seasonal climate changes are reflected in red deer teeth. Our analyses of sequential sub-samples from red deer second and third molars showed that enamel carbonate δ 18O values vary within teeth and that the pattern of intra-tooth isotopic variation broadly corresponds to that observed in precipitation δ 18O over an annual cycle. The pattern of intra-tooth isotopic variation and absolute values are similar for individuals born in the same year. As the population range in intra-tooth δ 18O values closely matches that estimated for the local precipitation and the calculated range in temperature corresponds with that recorded on the Isle of Rum, we conclude that red deer intra-tooth oxygen isotope signatures are a good palaeoclimate and seasonality proxy. In addition, all deer have recorded the lowest δ 18O of the cycle (winter minimum) in the same location of the M3 crown, demonstrating the potential utility of this sampling protocol to infer birth seasonality in red deer.

Quercus macrocarpa annual, early- and latewood widths as hydroclimatic proxies, southeastern Saskatchewan, Canada

Fluctuations in size of annual ring-widths of Quercus species suggest that environmental factors influence the size and density of vessels within the ring, either by acting as a limiting factor for growth or through fine tuning of the wood structure to environmental factors. The purpose of this study is to assess the potential of Q. macrocarpa to provide multiple dendroclimatic proxies for the Canadian Prairies, by investigating growth responses of annual, early- and latewood widths to regional climate variability. Results indicate that ring width chronologies, from southeastern Saskatchewan capture regional signals related to moisture and drought conditions. Correlations suggest that late-wood widths are more representative of annual ring-widths, than are early-wood widths, and are the best proxy of seasonal fluctuations in climate. Thus regression models that include latewood widths were able to account for more variance in the Palmer Drought Severity Index (PDSI) than when annual ring-widths are used as the only proxy. This study demonstrates that Q. macrocarpa can provide multiple dendroclimatic proxies for investigating large scale climatic fluctuations at annual and sub-annual time scales. It is novel in terms of sub-annual analysis of tree-rings in a region that previously lacked dendrochronological research.

Seasonal climatic fluctuations in the Late Triassic tropics—High-resolution oxygen isotope records from aragonitic bivalve shells (Cassian Formation, Northern Italy)

Three megalodontoid bivalves from the Upper Triassic Cassian Formation (N Italy, Dolomites) were sampled for δ 13C and δ 18O sclerochronology ( n = 270). With more than 1000 described invertebrate species, the Cassian Formation has one of the best records of an Early Mesozoic tropical fauna. In addition, the Cassian Formation is one of the very few Triassic occurrences with original aragonite preservation, with all studied shells consisting of pristine aragonite. The presence of aragonite and crossed lamellar as well as fibrous prismatic shell microstructures shown for the first time for Triassic megalodontoids suggests absence or minimal impact of diagenetic alteration. The δ 13C values range from 3.6 to 5.8‰ and show a distinct cyclicity in two studied shells whereas a third shell shows no obvious cyclicity. In one bivalve specimen, the cycles are somewhat offset from δ 18O cycles and in the other specimen δ 18O and δ 13C curves are inversely correlated. Seasonal variation in freshwater runoff including nutrient input and subsequent changes in plankton productivity during dry and wet seasons may explain δ 13C cyclicity. δ 18O values show a pronounced cyclicity within each of the studied shells varying from − 3.6 to − 1.4‰. The variations in δ 18O suggest a pronounced seasonality in Late Triassic tropical shallow waters of the western Tethys, with inferred seasonal temperature changes ranging from 24 to 32 °C. Influx of fresh water during the rainy seasons (mega-monsoon) or upwelling might also explain part of the variation in δ 18O. The presented data suggest that the diverse Cassian fauna lived under conditions characterized by warm sea-surface waters with a pronounced seasonality. Similar conditions are reported for some modern tropical settings.

Effect of vegetation cover on the hydrology of reclaimed mining soils under Mediterranean-Continental climate

Vegetation cover plays a major role in the restoration and stabilization of disturbed systems. The analysis of relationships between restored vegetation and soil hydrology has special relevance for the evaluation and operation of mining reclamation, particularly in Mediterranean-Continental environments, where climatic conditions restrict the development of continuous vegetation cover. The effect of herbaceous vegetation cover on soil hydrology was analysed by means of rainfall simulation (63 mm h− 1; 0.24 m2) in reclaimed soils derived from opencast coal mining (a non-saline and clay-loam textured spoil) in central-eastern Spain. A total of 75 simulation experiments were conducted at three different times throughout the year (late winter, summer and autumn) to control the influence of seasonal climatic fluctuations. Sediment concentrations in runoff and the runoff coefficient decreased exponentially with vegetation cover, while increases in steady infiltration rates were obtained with vegetation cover. Additional delays in runoff responses (longer time to runoff start and stabilization) and increases in the wetting front depth were observed with vegetation cover. Seasonal variations in soil surface state and moisture strongly influenced hydrological responses; although the influence of season on the analysed hydrological responses was attenuated by vegetation cover, especially in the case of infiltration rates. We also determined a practical ground cover threshold for site restoration and evaluation of over 50% vegetation cover, which could help achieve an optimum biological control of hydrological soil responses in the studied environment.

Can Climate Signals Inform Emergency Management? Preliminary Evidence

The emergency management community has widely discussed the long-term implications of global climate change for weather-related hazards such as floods, hurricanes, and droughts, but the community has paid relatively little attention to the connection between these hazards and shorter-term seasonal climate fluctuations (e.g., El Niño). This paper explores the potential for applying recent scientific and technical advances in the use of seasonal climate information to improve how emergency managers address such hazards risks and their associated disaster losses. The preliminary analysis presented here begins with a brief review of evidence from the research literature linking mid- and long-term forecasts to flood planning and management. We report on a small telephone survey of emergency managers involved in flood planning and management in 26 Oregon and Washington counties that experience interannual climate-variation that can increase the frequency or intensity of flooding. Our survey findings help illuminate the opportunities and obstacles for using climate science to inform emergency management. We then present results of a 2008 survey of emergency managers and educators that asks about the use of climate information for a wider range of weather-related hazards. We conclude by summarizing the opportunities for and obstacles to the use of climate information in emergency management.

Ecogeographic and evolutionary approaches to improving adaptation of autumn-sown chickpea ( Cicer arietinum L.) to terminal drought: The search for reproductive chilling tolerance

Terminal drought is the most important abiotic stress of dryland chickpea. The principal adaptive strategy of the crop is drought escape through early phenology. In regions where average temperatures at flowering <14–16 °C, such as southern Australia or northern South Asia, the lack of reproductive chilling tolerance forces chickpea to delay podset. This delay compromises drought escape by exposing chickpea to terminal drought during much of the pod filling phase, reducing yield potential and stability, depending on seasonal climatic fluctuations. This paper defines chickpea growing seasons in time throughout the crop's global production regions using published data and feedback from local breeders. This information is used to calculate and map regionally specific chickpea bioclimatic variables such as flowering phase temperatures and the peak rate of growing season temperature change. Flowering phase temperatures <14 °C are uncommon. Mediterranean climates in southern Australia, Chile, California and Portugal tend to be cool during flowering (<15.4 °C), while much of WANA is moderate to warm (15.4–24.4 °C), with exceptions in coastal N Africa, the Nile valley and higher elevations in Morocco, the Balkans, central Afghanistan, NE and SW Iran. Ethiopia contains a wide range of flowering phase temperatures depending on altitude. In South Asia flowering phase temperatures tend to decrease with increasing latitude, with large cool regions in the Punjab, N Haryana, N Uttar Pradesh and the Nepali terai. Superimposing the peak rates of temperature change within the growing season identifies habitats which are likely to be consistently cool throughout the reproductive phase by eliminating regions with transient chilling stress, such as much of N South Asia. It is suggested that reproductive chilling tolerance is rare in chickpea because of the late Neolithic shift from autumn to spring sowing in WANA, and subsequent dissemination into predominantly moderate to warm flowering habitats with only transient low temperature stress. The search for reproductive chilling tolerance should concentrate on these relatively uncommon consistently cool habitats. These are not well represented in the world chickpea collection, a shortcoming which is exacerbated by the lack of passport data in regions of potential interest from Iran to Central Asia. An alternative strategy is to search for reproductive chilling tolerance in the wild Cicer species, which have maintained a winter annual lifecycle and appear to be more cold tolerant than the cultigen. This approach is limited by the lack of germplasm. Currently, there are <30 original wild accessions in the primary genepool of chickpea ( C. reticulatum, n = 18; C. echinospermum, n = 10) in the world's genebanks, so more collection is required.

Developments in dynamical seasonal forecasting relevant to agricultural management

Recent developments in dynamical seasonal forecasting of potential relevance to agri- cultural management are discussed. These developments emphasize the importance of using a fully probabilistic approach at all stages of the forecasting process, from the dynamical ocean-atmosphere models used to predict climate variability at seasonal and interannual time scales, through the mod- els used to downscale the global output to finer scales, to the end-user forecast models. The final goal is to create an end-to-end multi-scale (both in space and time) integrated prediction system that pro- vides skilful, useful predictions of variables with socio-economic interest. Multi-model ensemble pre- dictions made with the leading European global coupled climate models as part of the DEMETER (Development of a European Multi-model Ensemble system for seasonal to inTERannual prediction) project are used as an example to illustrate the potential of producing useful probabilistic predictions of seasonal climate fluctuations and of applying them to crop yield forecasting.