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1.
A crop growth model developed in Canterbury, New Zealand was used to assess the potential of lentil (Lens culinaris) as a grain legume crop in the UK. The model was validated using five sowing dates at Durham (54.77°N, 1.58°W) in 1999. Predicted time to flowering was within 7 days of actual time to flowering and predicted seed yields were within 9% of actual yields. Actual yields ranged from 1.40 to 1.65 t ha‐1. Seed was of high quality. The model was used to predict rate of development and yields of spring and autumn sown lentils at eight sites along a transect from NW Scotland (Stornoway, 58.22°N, 6.32°W) to SE England (East Mailing, 51.28°N, 0.45°E) chosen to encompass important environmental gradients in the UK. In general, for a 1 May sowing with 150 or 250 mm plant available water (PAW) and a 1 October sowing with 150 mm PAW, predicted mean values over the period 1987–95 for maximum crop growth rate, maximum leaf area index, radiation intercepted, total dry matter produced and seed yield were closely positively related to monthly mean values for mean daily air temperature and increased along the transect from NW to SE UK. Time to flowering generally decreased along the transect from NW to SE UK ranging from 28 June to 9 July and from 20 May to 14 June with the May and October sowings respectively. For the 1 May sowing with 250 mm PAW, predicted mean seed yield ranged from 1.00 to 1.90 t ha‐1. For all sites, yield was very stable over the 9 yr period. For the 1 May sowing with 150 mm PAW, predicted mean seed yield ranged from 0.97–1.23 t ha‐1. Yields for the four more southerly sites were more variable at the lower PAW and, in exceptionally dry years, were substantially lower than average. For these sites, autumn sowing increased seed yields in exceptionally dry years and gave similar or greater mean seed yields to spring sowing with 250 mm PAW. For East Mailing, predicted yields for autumn sowing were on average 2.78 t ha‐1. Also, for Stornoway, because of its relatively high overwinter temperatures, the model predicted substantial increases in yield with autumn sowing. It is concluded that lentil has considerable potential as a grain legume crop in the UK.  相似文献   

2.
Nine determinate and two indeterminate-bush dry seed cultivars of P. vulgaris were grown in trials for four successive years. Mean annual yield of air dry seed (15% moisture content) varied between 222 and 398 g/m2. Most of the annual variation in yield was accounted for by differences in the quantity of nitrogen fertiliser applied and in the duration of bright sunshine during August. The annual mean harvest date varied between 20 September and 9 October. There was a significant negative correlation between the mean harvest date and the number of Ontario heat units accumulated between 20 May and 20 July. There were significant interactions between genotype and environment for both yield and harvest date; joint regression analysis of the interactions showed that five of the cultivars, which had previously been identified as cold tolerant in laboratory tests, all showed greater stability of yield and of maturity date than standard navy bean types. Environmental variation in the yield components of the cold tolerant selections tended to be compensatory, while that of the standard navy beans was additive in its effects on yield.  相似文献   

3.
4.
1. Temperate regions with fish communities dominated by cold‐water species (physiological optima <20 °C) are vulnerable to the effects of warming temperatures caused by climate change, including displacement by non‐native cool‐water (physiological optima 20–28 °C) and warm‐water fishes (physiological optima >28 °C) that are able to establish and invade as the thermal constraints on the expression of their life history traits diminish. 2. England and Wales is a temperate region into which at least 38 freshwater fishes have been introduced, although 14 of these are no longer present. Of the remaining 24 species, some have persisted but failed to establish, some have established populations without becoming invasive and some have become invasive. The aim of the study was to predict the responses of these 24 non‐native fishes to the warming temperatures of England and Wales predicted under climate change in 2050. 3. The predictive use of climate‐matching models and an air and water temperature regression model suggested that there are six non‐native fishes currently persistent but not established in England and Wales whose establishment and subsequent invasion would benefit substantially from the predicted warming temperatures. These included the common carp Cyprinus carpio and European catfish Silurus glanis, fishes that also exert a relatively high propagule pressure through stocking to support angling and whose spatial distribution is currently increasing significantly, including in open systems. 4. The potential ecological impacts of the combined effects of warming temperatures, current spatial distribution and propagule pressure on the establishment and invasion of C. carpio and Sglanis were assessed. The ecological consequences of Ccarpio invasion were assessed as potentially severe in England and Wales, with impacts likely to relate to habitat destruction, macrophyte loss and increased water turbidity. However, evidence of ecological impacts of Sglanis elsewhere in their introduced range was less clear and so their potential impacts in England and Wales remain uncertain.  相似文献   

5.
Spring wheat (Triticum aestivumL., ‘Chablis’) wasgrown under field conditions from sowing until harvest maturity,except for a 12-d period [70–82 days after sowing (DAS)coinciding with anthesis] during which replicated crop areaswere exposed to a range of temperatures within two pairs ofpolyethylene-covered temperature gradient tunnels. At 82 DAS,an increase in mean temperature from 16 to 25 °C duringthis treatment period had no effect on above-ground biomass,but increased ear dry weight from 223 to 327 g m-2and, at 83DAS, reduced root biomass from 141 to 63 g m-2. Mean temperatureover the treatment period had no effect on either above-groundbiomass or grain yield at maturity. However, the number of grainsper ear at maturity declined with increasing maximum temperaturerecorded over the mid-anthesis period (76–79 DAS) and,more significantly, with maximum temperature 1 d after 50% anthesis(78 DAS). Grain yield and harvest index also declined sharplywith maximum temperature at 78 DAS. Grain yield declined by350 g m-2at harvest maturity with a 10 °C increase in maximumtemperature at 78 DAS and was related to a 40% reduction inthe number of grains per ear. Grain yield was also negativelyrelated to thermal time accumulated above a base temperatureof 31 °C (over 8 d of the treatment from 5 d before to 2d after 50% anthesis). Thus, grain fertilization and grain setwas most sensitive to the maximum temperature at mid-anthesis.These results confirm that wheat yields would be reduced considerablyif, as modellers suggest, high temperature extremes become morefrequent as a result of increased variability in temperatureassociated with climate change.Copyright 1998 Annals of BotanyCompany Triticum aestivum, spring wheat, temperature, grain number, grain yield, root growth.  相似文献   

6.
This paper examines the mean flowering times of 11 plant species in the British Isles over a 58-year period, and the flowering times of a further 13 (and leafing time of an additional 1) for a reduced period of 20 years. Timings were compared to Central England temperatures and all 25 phenological events were significantly related (P<0.001 in all but 1 case) to temperature. These findings are discussed in relation to other published work. The conclusions drawn from this work are that timings of spring and summer species will get progressively earlier as the climate warms, but that the lower limit for a flowering date is probably best determined by examining species phenology at the southern limit of their distribution. Received: 21 October 1999 / Revised: 27 January 2000 / Accepted: 27 January 2000  相似文献   

7.
Direct sowing of Miscanthus seed could lower crop establishment costs, and increase the rate of grower uptake and biomass supply for the emerging bio‐economy. A replicated field trial was conducted at two contrasting UK sites: Aberystwyth (ABR) in mid‐Wales and Blankney (BLK) in Lincolnshire. These sites encompass the west–east meteorological gradient in the United Kingdom where the growing season at ABR is cooler and wetter while BLK is warmer and drier. Primed and unprimed Miscanthus sinensis seeds were sown directly onto the soil surface with and without a clear biodegradable mulch film, at nine dates interspersed from May to October. Average daily mean soil surface temperatures measured over the first 2 months after sowing under the mulch film were higher than control plots (2.7°C ABR and 4.2°C BLK). At both sites, the film covering also affected soil volumetric moisture relative to uncovered control plots (?3% ABR and 8% BLK), demonstrating the negative impact of mulch film when sowing on dry soil. Over nine sowings, seed germination at ABR under film varied between ?28% and +18% of germination under control conditions. Seedlings from the first three sowings at both sites under film had sufficient physiological maturity to survive the first winter period. At BLK, mulch film significantly increased tiller count and height in both the first and second years after sowing. At ABR, where temperatures were lower, film covering significantly increased tiller height but not count. Water priming had no significant effect on seed viability or germination in the field tests. Base temperatures for germination of primed and unprimed seeds on a thermal gradient plate were 7.0°C and 5.7°C, respectively, with a ± 1.7°C confidence interval. Based on our results for M. sinensis in the United Kingdom, we recommend the sowing of unprimed seed in May under film and only when the soil is moist.  相似文献   

8.
基于ORYZA2000模型的北京地区旱稻适宜播种期分析   总被引:3,自引:0,他引:3  
确定适宜播种期是制定合理的作物栽培管理方案的关键内容之一。在作物模型ORYZA2000有效性验证的基础上,以北京地区为例,利用该模型结合长期历史气候资料,对确定旱稻适宜播种期做了初步研究。结果表明:在不考虑水分因子条件下,北京地区旱稻297安全播期的范围较广,多年平均为3月26日-6月4日;受温度升高的影响,最早播期有提前趋势,而最晚播种期有延后趋势。在同一年份内,播期不同旱稻的产量也有一定的变化,呈现为先升高而后降低的趋势。播期过早或过晚导致生育期平均温度偏低是影响穗干物质累积且造成减产的主要原因,在适宜的播期范围内才能获得高产。以90%-100%当年最高产量潜力作为适宜播期的产量指标,确定北京地区旱稻297的适宜播期变化在5月11日-5月19日之间,相应的产量变化在6689-7257 kg/hm2范围内。研究方法可为其他地区旱稻的播期研究提供借鉴。  相似文献   

9.
Studies on the physico-chemical, microstructural characteristics and in vitro (under simulated gastric and small intestine conditions) starch digestibility of navy beans were carried out. The microstructure of raw and cooked beans observed through scanning electron microscopy (SEM) showed the presence of hexagonal or angular shaped cotyledon cells (50-100 μm size) containing starch granules with a size ranging between 10 and 50 μm. The extent of starch hydrolysis (%) after 120 min of in vitro gastro-intestinal digestion differed between whole navy beans (∼60%) and milled bean flour and bean starch (85-90%) after they were cooked under similar conditions. Starch hydrolysis (%) increased significantly when the cotyledon cells in the cooked whole navy beans were disrupted using high pressure treatment (French press). The storage of freshly cooked whole beans resulted in a lower (40-45%) starch hydrolysis whereas re-heating increased the same to 70-80% during in vitro small intestinal digestion. The SEM pictures of cooked navy bean digesta after different intervals of in vitro gastric and small intestinal digestion showed that the cotyledon cell structure is maintained well throughout the digestion period. However cotyledon cells appear shrunken and developed wrinkles during in vitro digestion. Particle size analysis of cooked bean paste taken before and after the in vitro gastro-intestinal digestion showed similar particle size distributions.  相似文献   

10.
In light of heightened interest in the response of pollen phenology to temperature, we investigated recent changes to the onset of Betula (birch) pollen seasons in central and southern England, including a test of predicted advancement of the Betula pollen season for London. We calculated onset of birch pollen seasons using daily airborne pollen data obtained at London, Plymouth and Worcester, determined trends in the start of the pollen season and compared timing of the birch pollen season with observed temperature patterns for the period 1995–2010. We found no overall change in the onset of birch pollen in the study period although there was evidence that the response to temperature was nonlinear and that a lower asymptotic start of the pollen season may exist. The start of the birch pollen season was strongly correlated with March mean temperature. These results reinforce previous findings showing that the timing of the birch pollen season in the UK is particularly sensitive to spring temperatures. The climate relationship shown here persists over both longer decadal-scale trends and shorter, seasonal trends as well as during periods of ‘sign-switching’ when cooler spring temperatures result in later start dates. These attributes, combined with the wide geographical coverage of airborne pollen monitoring sites, some with records extending back several decades, provide a powerful tool for the detection of climate change impacts, although local site factors and the requirement for winter chilling may be confounding factors.  相似文献   

11.

Background

Injuries are an increasingly important cause of death in children worldwide, yet injury mortality is highly preventable. Determining patterns and trends in child injury mortality can identify groups at particularly high risk. We compare trends in child deaths due to injury in four UK countries, between 1980 and 2010.

Methods

We obtained information from death certificates on all deaths occurring between 1980 and 2010 in children aged 28 days to 18 years and resident in England, Scotland, Wales or Northern Ireland. Injury deaths were defined by an external cause code recorded as the underlying cause of death. Injury mortality rates were analysed by type of injury, country of residence, age group, sex and time period.

Results

Child mortality due to injury has declined in all countries of the UK. England consistently experienced the lowest mortality rate throughout the study period. For children aged 10 to 18 years, differences between countries in mortality rates increased during the study period. Inter-country differences were largest for boys aged 10 to 18 years with mortality rate ratios of 1.38 (95% confidence interval 1.16, 1.64) for Wales, 1.68 (1.48, 1.91) for Scotland and 1.81 (1.50, 2.18) for Northern Ireland compared with England (the baseline) in 2006–10. The decline in mortality due to injury was accounted for by a decline in unintentional injuries. For older children, no declines were observed for deaths caused by self-harm, by assault or from undetermined intent in any UK country.

Conclusion

Whilst child deaths from injury have declined in all four UK countries, substantial differences in mortality rates remain between countries, particularly for older boys. This group stands to gain most from policy interventions to reduce deaths from injury in children.  相似文献   

12.
The incidence of food poisoning in England and Wales has been increasing for many years and it is now a major public health problem. Superimposed on this general rising trend is a well-established tendency for the number of cases of food poisoning to rise during the summer when warm weather favours the multiplication of pathogenic micro-organisms. This paper shows that weekly notifications of food poisoning in England and Wales are strongly associated with environmental temperatures, but that there are some important time lags in this relationship. The number of cases of food poisoning in a given week was only weakly correlated with the temperature of that week and the one preceding it. This suggests that factors operating close to the point of consumption within or outside the home are not the principal cause of the rise in food poisoning associated with warm summer conditions. There was a much stronger association with temperatures 2–5 weeks earlier, pointing to the importance of factors operating earlier in the food production or distribution system. The results of this study suggest that the food poisoning problem requires action by food producers and distributors as well as by consumers. Received: 15 May 2000 / Revised: 17 October 2000 / Accepted: 18 October 2000  相似文献   

13.
Northeast China (NEC) accounts for about 30% of the nation's maize production in China. In the past three decades, maize yields in NEC have increased under changes in climate, cultivar selection and crop management. It is important to investigate the contribution of these changing factors to the historical yield increases to improve our understanding of how we can ensure increased yields in the future. In this study, we use phenology observations at six sites from 1981 to 2007 to detect trends in sowing dates and length of maize growing period, and then combine these observations with in situ temperature data to determine the trends of thermal time in the maize growing period, as a measure of changes in maize cultivars. The area in the vicinity of these six sites accounts for 30% of NEC's total maize production. The agricultural production systems simulator, APSIM‐Maize model, was used to separate the impacts of changes in climate, sowing dates and thermal time requirements on maize phenology and yields. In NEC, sowing dates trended earlier in four of six sites and maturity dates trended later by 4–21 days. Therefore, the period from sowing to maturity ranged from 2 to 38 days longer in 2007 than it was in 1981. Our results indicate that climate trends alone would have led to a negative impact on maize. However, results from the adaptation assessments indicate that earlier sowing dates increased yields by up to 4%, and adoption of longer season cultivars caused a substantial increase in yield ranging from 13% to 38% over the past 27 years. Therefore, earlier sowing dates and introduction of cultivars with higher thermal time requirements in NEC have overcome the negative effects of climate change and turned what would have otherwise been a loss into a significant increase in maize yield.  相似文献   

14.
Capsule The third national Merlin survey estimated a UK population of 1162 breeding pairs (95% CI: 891–1462).

Aims To estimate the number of breeding Merlins (with associated 95% confidence intervals) in the UK and the four countries (Scotland, England, Wales and Northern Ireland), and to compare these with the relevant estimates from the 1993–94 Merlin survey. In addition, to calculate estimates of change for several regional populations with complete survey coverage during both national surveys.

Methods A subset of 10-km squares (Raptor Study Group squares and randomly sampled squares) was surveyed across the breeding distribution of Merlins in the UK using standardised methods devised during the 1993–94 national survey.

Results The population estimate for Merlins in the UK was 1162 breeding pairs, and in Britain was 1128 pairs (95% CI: 849–1427), which although 13% lower, was not significantly different from the British estimate of the 1993–94 survey. Scotland held the bulk (733 pairs) of the UK Merlin population, and smaller numbers of 301 pairs, 94 pairs and 32 pairs were estimated for England, Wales and Northern Ireland, respectively. The population estimate for Wales may have been biased upwards by low coverage in the south of the country. Marked declines were noted in several regional Merlin populations, particularly in areas of northern England.

Conclusions The 2008 Merlin survey suggests that the population in Britain has remained relatively stable since 1993–94, but with local declines, particularly in northern England. Currently, little is known about important drivers of regional population change in Merlins, but changes in land-use, prey populations and climate are likely to be important factors.  相似文献   

15.
Existing tourism-related climate information and evaluation are typically based on mean monthly conditions of air temperature and precipitation and do not include thermal perception and other climate parameters relevant for tourists. Here, we quantify climate based on the climate facets relevant to tourism (thermal, physical, aesthetical), and apply the results to the Climate-Tourism-Information-Scheme (CTIS). This paper presents bioclimatic and tourism climatological conditions in the Hunter Region—one of Australia’s most popular tourist destinations. In the Hunter Region, generally, temperatures below 15°C occur from April through October, temperatures less than 25°C are expected throughout the whole year, while humidity sits around 50%. As expected, large differences between air temperature and physiologically equivalent temperature (PET) were clearly identified. The widest differences were seen in summer time rather than in the winter period. In addition, cold stress was observed less than 10% of the time in winter while around 40–60% of heat stress was observed in summer time. This correlates with the highest numbers of international visitors, who usually seek a warmer weather, at the beginning of summer time (November and December) and also to the number of domestic visitors, who tend to seek cooler places for recreation and leisure, in late summer (January–March). It was concluded that thermal bioclimate assessment such as PET and CTIS can be applied in the Hunter region, and that local governments and the tourism industry should take an integrated approach to providing more relevant weather and climate information for both domestic and international tourists in the near future.  相似文献   

16.
气候变化对华北冬小麦生育期和灌溉需水量的影响   总被引:13,自引:0,他引:13  
胡玮  严昌荣  李迎春  刘勤 《生态学报》2014,34(9):2367-2377
利用华北4个气象站点1981—2010年冬小麦的生育期数据和气象资料,研究了华北平原典型区域冬小麦在气候变化条件下的生育期及各生育阶段灌溉需水量。结果表明:(1)过去30a来,华北地区冬小麦播种期和出苗期均有推迟趋势,且高纬度站点的变化趋势明显,其他生育期则呈提前趋势,而冬小麦全生育期表现为缩短;(2)华北冬小麦灌溉需水量在空间上从北到南、自东向西逐渐递减趋势;在时间上,东西部地区灌溉需水量变化趋势相反,东部地区呈逐渐增加趋势,而西部地区呈减小趋势;(3)冬小麦生育阶段的灌溉需水量变化不相同,播种—出苗、拔节—抽穗和抽穗—乳熟期灌溉需水量表现为减少趋势,而出苗—拔节和乳熟—成熟期则表现为增加趋势。就冬小麦整个生育期而言,华北西部地区灌溉需水量(北京密云站和石家庄栾城站)有减少趋势,分别减少6.72mm/10a和8.3mm/10a;而华北东部地区(天津宝坻站和邢台南宫站)的趋势正好相反,分别增加2.6mm/10a和7.08mm/10a。6个生育阶段灌溉需水量的年际波动程度依次为:播种—出苗期乳熟—成熟期抽穗—乳熟期拔节—抽穗期出苗—拔节期播种—成熟期;(4)气象要素对灌溉需水量的影响较复杂,其中灌溉需水量同有效降水量、相对湿度呈负相关,且相关关系极显著,与生育期长度存在微负相关关系,与日照时数、平均温度和风速呈显著正相关。同时,影响各生育阶段灌溉需水量的气象要素也存在差异,主要包括有效降水量、相对湿度和风速等。  相似文献   

17.
OBJECTIVE--To assess the prevalence of antibiotic resistance and serotype distribution among pneumococci in England and Wales in 1990 and 1995. DESIGN--Observational surveys in March 1990 and March 1995. During two weeks in each survey period all pneumococci isolated in public health laboratories in England and Wales were collected and assessed for sensitivity to antibiotics and the distribution of serogroups or serotypes. SETTING--The network of public health laboratories throughout England and Wales. SUBJECTS--1127 individual patient isolates of Streptococcus pneumoniae obtained during the two surveys. MAIN OUTCOME MEASURES--Sensitivity or resistance to a range of antibiotics; serogroup or serotype. RESULTS--The prevalence of intermediate or full resistance to penicillin increased from 1.5% in 1990 to 3.9% in 1995 and resistance to erythromycin increased from 2.8% to 8.6%. About 92% of isolates belonged to serogroups or serotypes included in the currently available pneumococcal vaccine. CONCLUSION--Resistance to penicillin and erythromycin has increased among pneumococci in England and Wales. Continued surveillance to assess further increases in the prevalence of pneumococcal resistance to antibiotics is essential.  相似文献   

18.
The high establishment costs of Miscanthus by clonal propagation are a barrier to widespread deployment. Direct sowing is the cheapest method, but limited field trials have given generally poor results. Miscanthus, a perennial grass with C4 photosynthesis has tropical origins, but is found growing both at high latitudes (>40°) and altitudes (>1000 m) in Asia. In this paper, we investigate if significant variation in the thermal requirements for germination exist in 10 Miscanthus sinensis half‐sib families and compare these with Panicum virgatum (Switchgrass – Trailblazer), Phalaris arundinaceae (Reed canary grass – P10) and Lolium perenne (perennial ryegrass cv AberDart) and maize (Zea mays cv Aviso). The comparisons were made on a thermal gradient bar with a controlled temperature oscillating ± 5 °C on a 12 h cycle and germination was monitored daily for 35 days at mean temperatures ranging from 5.3 to 26.5 °C. Base temperatures were calculated below which germination of at least 50% of viable seeds ceased. Base temperatures were lowest for L. perenne and Zea mays at 3.4 and 4.5 °C respectively; for different Miscanthus half‐sib families base temperatures ranged between 9.7 and 11.6 °C and these were higher than maize and switchgrass which share C4 photosynthesis with Miscanthus. Parameters derived from germination and temperature were used to predict germination patterns in Europe based on historical climate data. We predict that seed establishment of Miscanthus in spring time is unlikely to be viable in Northern Europe under present climatic conditions without crop management practices aimed at raising soil temperature, and that useful variation in thermal requirement for germination in Miscanthus is available which should facilitate seed germination in other regions.  相似文献   

19.
M.C. Radford 《Bird Study》2013,60(3):154-160
A census of breeding Ringed Plovers in the UK in 1984 revealed 7534 pairs and a further 1083 pairs were estimated, bringing the total to just over 8600 territorial pairs. Two-thirds of these were in Scotland. The Western Isles, particularly the dry machair, supported 2324 of these, 27% of the national total. Estimated numbers in England (2389) and Wales (224) showed, using the comparison of counted areas only, increases over 1973/74 of 19.6% and 21.1% respectively. Elsewhere, however, a similar comparison showed that numbers were stable or decreasing slightly. The large increase in the UK total over 1973/74 was primarily due to improved coverage in Scotland. Of the habitats used, open beaches throughout most of the UK and machair in the Western Isles were by far the most important. A trend was apparent, most clearly in England, for birds to spread to inland sites. The concentration of Ringed Plovers into nature reserves and other protected sites, especially in England, is discussed, along with the implications for the design of access arrangements to such areas.  相似文献   

20.
In England and Wales hospital admissions for childhood asthma almost trebled over the period 1975-81. This may have reflected a true increase in the incidence of acute asthma, a swing from primary to hospital care, or both. The trend was not due to a change in diagnostic fashion. Monthly admissions showed a pronounced seasonal variation with fewest admissions in winter, rising in spring and early summer to peak in the autumn. A deep admission trough was present in August. The monthly admission profile was very similar throughout England and Wales, suggesting that major "trigger" factors were responsible.  相似文献   

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