Continentality Research Articles

Limited linkages of aboveground and belowground phenology: A study in grape.

Plant phenology influences resource utilization, carbon fluxes, and interspecific interactions. Although controls on aboveground phenology have been studied to some degree, controls on root phenology are exceptionally poorly understood. We used minirhizotrons to examine the timing of grape root production over 5 yr in Fredonia, New York, USA, in a humid continental climate; and over 3 yr in Oakville, California, USA, in a Mediterranean climate. We used data from previous experiments to examine the relationship of root phenology with aboveground phenology. We compared interannual variability in root and shoot growth and determined the influence of abiotic factors on the timing of root initiation, peak root standing crop, peak root growth rate, and cessation of root growth. Root phenology was not tightly coupled with aboveground phenological periods. Both sites typically had one yearly root flush and high interannual variability in root growth. Root phenology was more variable in California than in New York. In this and other published studies, interannual variation in root phenology was greater than variation in aboveground phenology. The three phenological phases of root growth-root initiation, peak root growth, and root cessation-were related to different suites of abiotic factors. Root phenology is highly variable among years. Analysis of potential controlling factors over several years suggest that belowground phenological phases should be analyzed separately from each other. If aboveground grape phenology responds differently than belowground phenology to changes in air temperature, global warming may further uncouple the timing of aboveground and belowground growth.

Dry matter production, radiation interception and radiation use efficiency of potato in response to temperature and nitrogen application regimes

A meta-analysis of 12 irrigated field experiments conducted from 2003 to 2014 was performed to examine the combined effects of climate variability and nitrogen (N) application on dry matter production of potatoes in a humid temperate climate. Seasonal mean temperature ranged from 15.3 to 17.7°C while N rate varied from 0 to 180kgha−1. Statistical analysis using mixed modelling detected two clear features: Both temperature and N supply were important factors for dry matter production. Higher temperatures were associated with decreased dry matter production mainly through its negative effect on radiation use efficiency (RUE) when comparing inter-annual variation in dry matter production. The loss of tuber dry matter was c. 10% per °C, which is higher than estimated in previous studies. Specifically, compared to mean air temperature from end of tuber initiation to maturity, mean air temperature from emergence to end of tuber initiation was more important for dry matter production. N supply promoted dry matter production (p<0.001) mainly by increasing accumulated intercepted radiation during the growing season (p<0.001) rather than radiation use efficiency. Elevated temperature reduced the potential tuber dry matter production as well as the N supply that was needed to maximize tuber dry matter yield. Therefore, in a season when temperature is high, less N should be supplied to potato crops.

Investigate urban design quality of cities entry points

Entry points as one of the main components of physical and spatial structure of the city, despite the importance that have in terms of physical, functional and aesthetic with heterogeneous and incompatible land uses have turned into a detached, lacking identity and disturbed space. Historic examination of cities entrance represents changing coordinated and defined gates, towers and walls of old towns into entrance corridors with ugly buildings and old houses, repair shops, military applications, scrap car which showing an uncontrolled increase of development in today cities of the country. Adverse environmental assessment of the entry points of the city and its negative effects on residents and newcomers and the role that urban design should have in quality, visual and performance improvement of these spaces is the main objective of this research. First, the role of entrance space in traditional architecture and entrance spaces of historic cities should be considered and the relationship between performance and structure of city entrance space with the objectives of its inhabitants and the ability of this space to meet the needs of past citizens should be reviewed. Then, the entrance characteristics of several cities in hot and humid temperate climate of Iran with emphasis on aspects of tourism were reviewed and city relationship with outer space is searched. In the end according to the obtained results and some realities, criteria and operational conditions for designing entrance spaces will be offered.

Controlling tile drainage during the growing season in Eastern Canada to reduce nitrogen, phosphorus, and bacteria loading to surface water

Drainage water management such as controlled tile drainage (CTD) is one means to help meet pollution mitigation targets and boost crop yields. In this study, CTD was retrofit to existing tile drained fields in eastern Ontario, Canada (humid continental climate) to study water quality benefits. A suite of paired field systems were used to compare CTD tile drainage quality with conventional tile drainage quality for nine growing seasons (2005–2013), translating to 35 field-crop years. Field crops were corn, soybean and forage. For CTD fields, controlled tile drainage was employed only during the growing season (time period when comparisons were made) due to surface runoff/erosion and growing season length concerns associated with non-growing season flow control. Water quality targets in tile effluent included: nitrate, ammonium, total phosphorus, dissolved reactive phosphorus, and fecal indicator bacteria such as E. coli, and Enterococci. Respectively, there were 60, 51, 58, 66, 66, 76, and 25% reductions in above noted drainage water fluxes and water quality targets as a result of CTD (for all 35 field-crop years combined). Concurrent environmental and potential public health benefits of managing tile drainage during the growing season were demonstrated; moreover, over the course of the study, corn and soybean yields were significantly boosted by CTD.

Trends in the Incidence Rates of Chronic Hepatitis B in Poland in the Years 2005 - 2013.

BackgroundThe prevalence of newly-diagnosed cases of chronic hepatitis is decisive for the overall incidence rate of hepatitis B observed in Poland.ObjectivesWe aimed to determine the chronic hepatitis B incidence trends in Poland, taking into consideration the ages, genders, and environments of the patients.MethodsThe study is based on aggregated data from Polish descriptive epidemiological studies for the period of 2005 to 2013 (i.e., hepatitis B incidence numbers and ratios, including mixed HBV and HCV infections) as published in the annual bulletins Choroby zakazne i zatrucia w Polsce (Infectious diseases and poisonings in Poland] drawn up by the laboratory for the monitoring and analysis of epidemiological status of the department of epidemiology at the national institute of public health - national institute of hygiene (NIPH-NIH). Poland, a central European country situated in the humid continental climate zone, is classified as a highly developed country. In the analyzed period, the Polish population consisted of about 38 million people, more than 19 million of whom were women, and more than 18 million of whom were men. Among European countries, Poland has the smallest number of national and ethnic minorities. For the purposes of epidemiological supervision, a special definition of acute hepatitis B was adopted in Poland in 2005, which facilitated separate registration of acute and chronic cases.ResultsA significantly increasing chronic hepatitis B incidence trend was observed in the population of Poland, with considerable increases in incidence rates for both men and women alike. The incidence rates for inhabitants of both urban and rural areas also showed an increasing tendency. Chronic hepatitis B occurred more frequently in men and in urban areas. For each of the five-year age groups encompassing patients between 20 and 54 years of age, the increase in the incidence rate proved to be significant.ConclusionsThe registered increase in the incidence rate of chronic hepatitis B in Poland is a consequence of the new registration of cases of chronic hepatitis B acquired in the past. The problem of chronic hepatitis B can be solved by improving epidemiological supervision, enhancing the detection of frequently asymptomatic infections, and by providing easier access to optimized therapies.

Using the root spread information of pioneer plants to quantify their mitigation potential against shallow landslides and erosion in temperate humid climates

The aim of this paper was to quantify the mitigation potential of pioneer herbs against shallow landslides and erosion in temperate humid climates and to identify key plant information to aid species selection for slope stabilisation. The objectives ranged from the study of the climate, soil and root spread of three native perennial herbs growing on a landslide-prone slope in Northeast Scotland to the verification of an upgraded spatially distributed eco-hydrological model in order to test whether root spread information can be provided cost-effectively in temperate humid climates. The retrieved information on root spread was then used to evaluate the slope stabilisation potential of the pioneer herbs in the topmost soil horizons using a limit equilibrium method.The results indicated that pioneer herbs, although presenting climate-influenced shallow root systems, could noticeably contribute to reducing soil mass loss and landslides. This was largely determined by the plant biomass and allometry, the latter being a potential readily measurable proxy for species selection in slope stabilisation that will need further investigation. Additionally, our observations supported the model predictions remarkably well when site-specific inputs were employed, showing that the proposed model is a suitable and cost-effective tool to provide spatial root spread information for eco-engineering purposes in temperate humid climates.

Response of the hyporheic zone to transient groundwater fluctuations on the annual and storm event time scales

AbstractThe volume of the water stored in and exchanged with the hyporheic zone is an important factor in stream metabolism and biogeochemical cycling. Previous studies have identified groundwater direction and magnitude as one key control on the volume of the hyporheic zone, suggesting that fluctuation in the riparian water table could induce large changes under certain seasonal conditions. In this study, we analyze the transient drivers that control the volume of the hyporheic zone by coupling the Brinkman‐Darcy equation to the Navier‐Stokes equations to simulate annual and storm induced groundwater fluctuations. The expansion and contraction of the hyporheic zone was quantified based on temporally dynamic scenarios simulating annual groundwater fluctuations in a humid temperate climate. The amplitude of the groundwater signal was varied between scenarios to represent a range of annual hydrologic forcing. Storm scenarios were then superimposed on the annual scenario to simulate the response to short‐term storm signals. Simulations used two different groundwater storm responses; one in‐phase with the surface water response and one 14 h out‐of‐phase with the surface water response to represent our observed site conditions. Results show that annual groundwater fluctuation is a dominant control on the volume of the hyporheic zone, where increasing groundwater fluctuation increases the amount of annual variation. Storm responses depended on the antecedent conditions determined by annual scenarios, where the time of year dictated the duration and magnitude of the storm induced response of the hyporheic zone.

Record dry summer in 2015 challenges precipitation projections in Central Europe.

Central Europe was characterized by a humid-temperate climate in the 20th century. Climate change projections suggest that climate in this area will shift towards warmer temperatures by the end of the 21st century, while projected precipitation changes are highly uncertain. Here we show that the 2015 summer rainfall was the lowest on record since 1901 in Central Europe, and that climate models that perform best in the three driest years of the historical time period 1901–2015 project stronger drying trends in the 21st century than models that perform best in the remaining years. Analyses of precipitation and derived soil moisture reveal that the 2015 event was drier than both the recent 2003 or 2010 extreme summers in Central Europe. Additionally there are large anomalies in satellite-derived vegetation greenness. In terms of precipitation and temperature anomalies, the 2015 summer in Central Europe is found to lie between historical climate in the region and that characteristic of the Mediterranean area. Even though the models best capturing past droughts are not necessarily generally more reliable in the future, the 2015 drought event illustrates that potential future drying trends have severe implications and could be stronger than commonly assumed from the entire IPCC AR5 model ensemble.

Reduction of Growth and Reproduction of the Biotrophic Fungus Blumeria graminis in the Presence of a Necrotrophic Pathogen.

Crops are attacked by many potential pathogens with differing life-history traits, which raises the question of whether or not the outcome of infection by one pathogen may be modulated by a change in the host environment brought on by infection by another pathogen. We investigated the host-mediated interaction between the biotroph Blumeria graminis f.sp. tritici (Bgt), the powdery mildew pathogen of wheat, and the necrotroph Zymoseptoria tritici, which has a long latent, endophytic phase following which it switches to a necrotrophic phase, resulting in the disease symptoms of Septoria tritici blotch. Both diseases are potentially severe in humid temperate climates and are controlled by fungicides and by growing wheat varieties with partial resistance. The compatible interaction between Z. tritici and the host reduced the number, size, and reproductive capacity of mildew colonies that a normally virulent Bgt isolate would produce but did not significantly alter the early development of Bgt on the leaf. The effect on virulent Bgt was elicited only by viable spores of Z. tritici. Notably, this effect was seen before the necrotic foliar symptoms induced by Z. tritici were visible, which implies there is a physiological interaction during the latent, endophytic period of Z. tritici, which either takes place directly between this fungus and Bgt or is mediated by the wheat leaf. Information on how different pathogens interact in host plants may allow plant breeders and others to improve the design of screening trials and selection of germplasm.

Ecosystem Water-Use Efficiency of Annual Corn and Perennial Grasslands: Contributions from Land-Use History and Species Composition

Carbon and water exchanges between vegetated land surfaces and the atmosphere reveal the ecosystem-scale water-use efficiency (WUE) of primary production. We examined the interacting influence of dominant plant functional groups (C3 and C4) and land-use history on WUEs of annual corn and perennial (restored prairie, switchgrass and smooth brome grass) grasslands in the US Midwest from 2010 through 2013. To this end, we determined ecosystem-level (eWUE) and intrinsic (iWUE) WUEs using eddy covariance and plant carbon isotope ratios, respectively. Corn, switchgrass, and restored prairie were each planted on lands previously managed as grasslands under the USDA Conservation Reserve Program (CRP), or as corn/soybean rotation under conventional agriculture (AGR), while a field of smooth brome grass remained in CRP management. The iWUEs of individual C3 plant species varied little across years. Corn had the highest (4.1) and smooth brome grass the lowest (2.3) overall eWUEs (g C kg−1 H2O) over the 4 years. Corn and switchgrass did not consistently show a significant difference in seasonal eWUE between former CRP and AGR lands, whereas restored prairie had significantly higher seasonal eWUE on former AGR than on former CRP land due to a greater shift from C3 to C4 species on the former AGR land following a drought in 2012. Thus, differences in grassland eWUE were largely determined by the relative dominance of C3 and C4 species within the plant communities. In this humid temperate climate with common short-term and occasional long-term droughts, it is likely that mixed grasslands will become increasingly dominated by C4 grasses over time, with higher yields and eWUE than C3 plants. These results inform models of the interaction between carbon and water cycles in grassland ecosystems under current and future climate and management scenarios.

Whole‐Body Heat Loss is Enhanced in Older Adults Following a Summer in a Humid Continental Climate

It has recently been shown that older adults have a reduced capacity to dissipate heat during exposure to extreme heat compared to their younger counterparts, resulting in a 1.7‐fold greater increase in body heat storage. However, it currently remains unclear whether older adults demonstrate any seasonal adaptations in their ability to dissipate over the course of a typical hot humid summer (e.g. Central Canada). Therefore, the purpose of this study was to examine the effects of aging on whole‐body heat loss and heat storage during an extreme heat exposure prior to (before June) and at the end of the summer (September). Five young (Young, age: 25 ± 3 years; body fat: 19 ± 6%) and five older (Older, age: 64 ± 7 years; body fat: 26 ± 9%) adults matched for body weight (Young: 82 ± 18 kg; Older: 86 ± 12 kg) and body surface area (Young: 1.9 ± 0.2 m2; Older: 2.0 ± 0.2 m2) rested for 3 hours in the heat (44°C, 30% RH). Whole‐body heat loss and metabolic heat production were measured continuously by direct and indirect calorimetry, respectively. Body heat storage was calculated as the temporal summation of heat production and heat loss. Our results show that the older adults had a reduced rate of whole‐body heat loss at the 1‐hour (Young: 105 ± 20 W vs. Older: 76 ± 12 W, p=0.021) and 2‐hour (Young: 115 ± 28 W vs. Older: 83 ± 11 W, p=0.048) time points prior to the start of summer relative to their younger counterparts. No differences were measured between age groups at the end of the 3‐hour heat exposure (p&gt;0.05). As a result of the lower rate of heat loss, the older adults stored 1.3‐fold more heat than the young adults (170 ± 72 kJ, p=0.01). Following the summer period, no differences in the rate of whole‐body heat loss were measured between groups throughout the 3‐hour heat exposure. As a consequence, the change in body heat storage was similar between age groups (Young: 196 ± 113 kJ vs. Older: 226 ± 102 kJ, p=0.67), demonstrating that older adults were able to reduce the amount of heat stored within their body by 43% after 3 months of summer heat exposure in a humid continental climate. These results show that seasonal adaptations can improve whole‐body heat dissipation in older adults, thereby mitigating the age‐related impairments in the body's physiological capacity to dissipate heat during an extreme heat exposure.Support or Funding InformationFunding support: This study was funded by the Canadian Institutes of Health Research (286363, grant held by Dr. Glen P. Kenny).

Streamflow variability in the Chilean Temperate-Mediterranean climate transition (35°S–42°S) during the last 400 years inferred from tree-ring records

As rainfall in South-Central Chile has decreased in recent decades, local communities and industries have developed an understandable concern about their threatened water supply. Reconstructing streamflows from tree-ring data has been recognized as a useful paleoclimatic tool in providing long-term perspectives on the temporal characteristics of hydroclimate systems. Multi-century long streamflow reconstructions can be compared to relatively short instrumental observations in order to analyze the frequency of low and high water availability through time. In this work, we have developed a Biobio River streamflow reconstruction to explore the long-term hydroclimate variability at the confluence of the Mediterranean-subtropical and the Temperate-humid climate zones, two regions represented by previous reconstructions of the Maule and Puelo Rivers, respectively. In a suite of analyses, the Biobio River reconstruction proves to be more similar to the Puelo River than the Maule River, despite its closer geographic proximity to the latter. This finding corroborates other studies with instrumental data that identify 37.5°S as a latitudinal confluence of two climate zones. The analyzed rivers are affected by climate forcings on interannual and interdecadal time-scales, Tropical (El Nino Southern Oscillation) and Antarctic (Southern Annular Mode; SAM). Longer cycles found, around 80-years, are well correlated only with SAM variation, which explains most of the variance in the Biobio and Puelo rivers. This cycle also has been attributed to orbital forcing by other authors. All three rivers showed an increase in the frequency of extreme high and low flow events in the twentieth century. The most extreme dry and wet years in the instrumental record (1943–2000) were not the most extreme of the past 400-years reconstructed for the three rivers (1600–2000), yet both instrumental record years did rank in the five most extreme of the streamflow reconstructions as a whole. These findings suggest a high level of natural variability in the hydro-climatic conditions of the region, where extremes characterized the twentieth century. This information is particularly useful when evaluating and improving a wide variety of water management models that apply to water resources that are sensitive to agricultural and hydropower industries.

Assessment of factors enabling halite formation in a marsh in a humid temperate climate (Ajó Marsh, Argentina)

The formation of evaporites associated with the final stages of the precipitation sequence, such as the case of halite, is frequent in marshes in arid areas, but it is not to be expected in those humid climates. This work, by means of the study of the hydrological, climatic and land use conditions, identifies the factors that allow the formation of saline precipitations in a marsh located in a humid climate area. The results obtained show that the exclusion of the marsh as a result of the embankment is the main reason for the presence of halite. It is to be expected that in the future the growth of the embanked marsh areas, together with the climatic and tidal condition tendencies recorded, will favour a higher rate of formation of evaporite salts. The identification of these factors makes it possible to set basic sustainable management guidelines to avoid soil salinisation.

Formation of an intra-orogenic transtensional basin: the Neogene Wagrain basin in the Eastern Alps

The Neogene (ca. Ottnangian to Lower Badenian) Wagrain basin formed within a halfgraben, close to the north-eastern edge of the exhuming and uplifting Neogene Tauern metamorphic core complex, along the ENE-trending, ca. orogen-parallel sinistral-transtensional Salzach-Enns and Mandling fault systems of the Eastern Alps. Based on a pronounced colour change from thin basal reddish, hematite-rich conglomerates to grey-brownish clastics, the basin infill records a climate change from a subtropical to a humid temperate climate. The change is used as a proxy for the dating of the basin as a similar regional climate shift has been reported, e.g., from other fault-bounded basins in the Eastern Alps and from the base Styrian basin predating there Ottnangian coal-bearing deposits. The lithofacies evolution of the Wagrain basin fill shows initial rapid subsidence and infilling by fluvial, massive, coarse-grained conglomerates and subsequent mica-rich immature sandstones deposited in a prodelta environment of a lake. The conglomerates were mainly shed from a polymetamorphic, medium-grade metamorphic basement similar to the Austroalpine Altkristallin basement complex, which is not exposed in the present surroundings of the basin. Provenance studies particularly suggest the Schladming/Bosenstein and Wolz Micaschist complexes as possible sources. The sandstones are extremely rich in mica, similar to ones found in many late-stage orogenic sandstones of other orogens, and garnet. Provenance analysis contrasts recent models for the Neogene evolution of the Eastern Alps, which assume a phyllitic source for similar conglomerates exposed further north and northeast. Fault and striae of the Wagrain basin fill allow deduce two post-depositional palaeostress tensor orientations: WNW-ESE extension and ca. E-W contraction. This data is consistent with palaeostress development along the Salzach-Enns fault, which also confines the Tauern metamorphic core complex, and shows an evolution from sinistral transtensional to sinistral transpressional to post-depositional dextral transpression.

Hillslope-storage and rainfall-amount thresholds as controls of preferential stormflow

Summary Shallow saturated subsurface flow is a dominant runoff mechanism on hillslopes of headwater catchments under humid temperate climate. Its timing and magnitude is significantly affected by the presence of preferential pathways. Reliable prediction of runoff from hillslope soils under such conditions remains a challenge. In this study, a quantitative relationship between rainfall, stormflow, and leakage to bedrock for hillslopes, where lateral preferential runoff represents a dominant part of the overall response, was sought. Combined effects of temporal rainfall distribution and initial hillslope saturation (antecedent moisture conditions) on stormflow, leakage to bedrock, and overall water balance were evaluated by conducting simulations with synthetic rainfall episodes. A two-dimensional dual-continuum model was used to analyze hydrological processes at an experimental hillslope site located in a small forested headwater catchment. Long-term seasonal simulations with natural rainfall indicated that leakage to bedrock occurred mostly as saturated flow during major runoff events. The amount of rainfall needed to initiate stormflow appeared as a dynamic hillslope property, depending on temporal rainfall distribution, initial hillslope storage, and the spatial distribution of soil water within the hillslope. No single valued rainfall threshold responsible for triggering stormflow was found. Rainfall–stormflow as well as rainfall–leakage relationships were found highly nonlinear for low initial hillslope saturations. Temporal rainfall distribution affected the amount of rainfall necessary to initiate stormflow more than it did the amounts of stormflow or leakage to bedrock. In spite of a simple hillslope geometry with constant slope and parallel soil–atmosphere and soil–bedrock interfaces considered in the analysis, the applied model predicted a hysteretic behavior of storage–discharge relationship. The results showed a mutual interplay of components of hillslope water balance exposing a nonlinear character of the hillslope response. The study provided a quantitatively coherent insight in the hydraulic functioning of hillslopes where preferential flow constitutes a dominant part of stormflow.

Soil development in a Quaternary fluvio-lacustrine paleosol sequence in Southern Italy

The aim of this paper is to enrich our knowledge of an important paleosol succession located in Bojano basin of the southern Apennines (Italy), with new pedological, geochemical and magnetic data. The studied area consists of alluvial and fluvial-lacustrine sequences (>160 m) dating from the Middle Pleistocene (0.5 Ma). The study area shows the presence of recent soil consisting of well-developed Andosols (RS), and several clastic sedimentary levels alternating with four layers (Solum I, II, III and IV) of paleosols. Soil and paleosols were analyzed by laser grain size distribution (GSD), diffuse reflectance spectroscopy (DRS), trace elements, and magnetic properties in order to evaluate the relative contributions of pedogenic and detrital components. Results showed that the finest pedogenic ferrimagnetic grains exhibit two trends with respect to the degree of pedogenesis indicate two different pedoclimate formations. The paleosol sequence consists of highly-weathered Vertisols (Solum I and IV) and of less weathered Entisols (Solum II, III). The recent soil (Andosol) has a strong bimodal distribution formed mostly by coarse silt-size particles related to the volcanic parent material. Solum I showed a sharp unimodal clay GSD while Solum III and IV were composed of bimodal GSD with high percentages of fine silt-size particles. On the basis of the trace element content and Gt/χfd ratio, all Solum (I, II, III, IV) exhibited low weathering pedogenesis compared with RS and negligible contribution to the magnetic properties of the coarse fractions. This occurs in Vertisols which developed under humid temperate climates (Solum I and SIV) and formed below the layer of Neapolitan Yellow Tuff, developed after 12–15 ka BP. In Solum, II, III the finest sedimentary levels, the low rate of pedogenesis could have developed under more cold climatic conditions after the last eruption (Campanian Ignimbrite, 39 ka) in the Late Pleistocene.

Reclamation of intensively managed soils in temperate regions by addition of wood bottom ash containing charcoal: SOM composition and microbial functional diversity

Wood bottom ash (BA), a complex mixture of mineral ash and moderate amounts of charcoal, can be used as a fertilizer in agricultural and forestry systems. BA is generated as a by-product of biomass combustion and may become a major source of pyrogenic organic matter (OM) as a result of the current high demand for biomass energy. However, very few studies have investigated how the application of BA to land affects soil organic matter (SOM) quality and soil biological properties.In the present study, changes in soil microbial community and community level physiological profile were related to changes in SOM composition (element analysis and 13C CP–MAS NMR) and thermal stability (DSC). The parameters were monitored throughout 3 years in a field experiment in which a degraded soil (acidic, poorly drained and low SOM content) was treated with different doses (16 and 32Mgha−1) of each of two types of BA (fly ash and mixed ash). The treatments led to changes in SOM composition that affected soil microbial communities. The data suggest that some of the pyrogenic OM in the BA may have been mineralized by soil microorganisms. The relatively low recalcitrance of the charcoal, as well as the priming effect of labile organic compounds and the higher nutrient availability may have favoured the process. Although application of BA to land may be useful for restoring fertility and the C-sequestration capacity of soil, the charcoal contained in this type of ash may be susceptible to microbial degradation in humid temperate climate zones and is not stable in the long term.

Lower farrowing rate in female pigs associated with higher outdoor temperatures in humid subtropical and continental climate zones in Japan

The aim of this study was to examine the respective associations between farrowing rate and either environmental or production factors in female pigs in commercial herds. We analyzed 264,057 records of females serviced in 101 Japanese herds located either in humid subtropical or humid continental climate zones. Outside environment data were obtained from 21 weather stations located close to the respective herds. Mean daily average temperatures (Tavg) and relative humidity for the 21-day pre-service periods for each female were coordinated with that female’s performance data. Generalized linear models were applied to the data for each parity. Overall average farrowing rate (± SE) was 85.2 ± 0.07%, and the mean daily average temperature (range) and relative humidity were 15.0 (−8.1 to 32.7)°C and 68.1 (19-99)%, respectively. Higher Tavg was associated with lower farrowing rate in all parity groups (P < 0.05). Farrowing rates of females in all parities decreased non-linearly as pre-service Tavg increased from 15 to 30°C (P < 0.05). Decreases ranged from 83.1-71.3% in parity 1 to 85.1% to 80.0% in parity 5. Also, delayed gilt age at first-mating, re-servicing, and a weaning-to-first-mating interval of 7 days or longer were associated with lower farrowing rate in either gilts or sows, or both (P < 0.05). However, there were no associations between farrowing rate and either pre-service humidity (P ≥ 0.09) or lactation length (P ≥ 0.06) in any parity. Therefore, we recommend that producers pay particular attention to females at risk of having reproductive failure, and apply cooling systems to prevent a decrease in farrowing rate for heat-stressed female.

Somatic Embryogenesis of Abies cephalonica Loud.

Greek fir (Abies cephalonica Loudon) belongs to the Mediterranean fir species and is widely distributed in the mountains of Central and Southern Greece. Considering a climatic scenario, infestation by pathogens or insects and fire episodes, it has been proposed that Mediterranean firs could be in danger in some parts of their present range but, on the other hand, could also replace other species in more northern zones with temperate humid climates (e.g., silver fir, Abies alba Mill.). As fir species are generally highly productive and therefore important for commercial forestry, they have traditionally been involved in conventional tree improvement programs. A lot of effort has been put into the development of vegetative propagation methods for firs, in order to rapidly gain the benefits of traditional breeding to be utilized in reforestation. The present paper provides up to date information on protocols for somatic embryogenesis (i.e., the most promising in vitro method for vegetative propagation) of Greek fir. Moreover, the protocols for cryopreservation and long-term storage of embryogenic material are described as well.

The ability of cover crops to reduce nitrogen and phosphorus losses from arable land in southern Scandinavia and Finland

This review summarizes current knowledge from the literature and experimental studies on the role of cover crops (CCs) in reducing nitrogen (N) leaching and phosphorus (P) losses to waters under the marine and humid continental climate conditions of southern Scandinavia and Finland. Field leaching studies from 11 sites indicate that undersown ryegrass (Lolium spp.) CCs are robust, with average N uptake in aboveground CC biomass of 7 to 38 kg N ha−1 (6.2 to 34 lb N ac−1). Use of CCs sown at harvest (e.g., crucifers) is restricted to southern Scandinavia for climate reasons. The mean relative reduction in N leaching reported for all CCs investigated was 43%, but it ranged between 62% increase instead of a reduction after a red clover (Trifolium pratense) CC on a clay soil to a reduction of 85% to 89% with a perennial ryegrass CC on sandy soils in Denmark (36 to 51 kg ha−1 [32 to 46 lb ac−1]). The data indicate that CCs do not substantially reduce total P losses by runoff and leaching. The effects of CCs on total P leaching varied between a relative increase of 86% and a decrease of 43%. Climate conditions involving freezing-thawing during winter increased the risk of losses of dissolved P from CC biomass. CCs have been implemented to varying degrees into agri-environmental programs. They are mandatory in Denmark and subsidized in Norway, Sweden, and Finland. CCs are grown on 8% of arable land in Denmark, 5% in Sweden, 1% in Finland, and 0.5% in Norway, but CC area is now increasing dramatically in Finland due to a new subsidy program. In all countries there is a need, and potential, for increased use of CCs, but there are several constraints, particularly reduced interest among farmers. There is a clear need to identify CC systems and develop implementation strategies for appropriate distribution of CCs on different soils and regions with respect to required reductions in N leaching and P losses. For this, more knowledge is required, especially about the effect of CCs on P losses (e.g., the effect of species with different partitioning between shoot and root biomass and the effects of CC systems with harvesting of biomass). There is also a need to devise balanced solutions for maintaining and increasing the frequency of CCs in crop rotations to exploit the possible benefits of CCs in reducing nutrient losses.