气候变化背景下中国北方干湿区降水资源变化特征分析

中国北方地区降水资源空间差异较大且种植结构迥异,细致分析北方不同干湿区降水资源的变化规律和分布特征,可为北方地区合理利用降水资源,调节种植结构,适应气候变化提供科学参考。该文利用中国北方15个省市308个气象站点1961-2010年逐日降水资料,以1981年为时间节点,将过去50 a分为1961-1980年和1981-2010年两个时段,基于干旱区、半干旱区和半湿润区划分标准,明确了与1961-1980年相比,1981年以来北方干旱区、半干旱区和半湿润区空间变化特征;依据中国气象局降水量等级标准及春夏秋冬四季划分标准,系统分析了北方三大区域内小雨、中雨、大雨及暴雨各等级降水量和降水日数在全年降水量和降水日数中的比例,以及降水在一年四季中的分配特征。研究结果表明:气候变化背景下,1981年以来西北地区的干旱区面积减少,东北地区的半湿润区面积减少,而半干旱区面积扩大明显。研究时段内干旱区年降水量呈显著增加趋势,最近30a各等级降水量和降水日数均高于1980年之前的20a,其中小雨、中雨等级增加幅度最大;季节变化中,尤以冬季最明显。半干旱区和半湿润区年降水日数均呈显著下降趋势,最近30 a小雨等级降水量和降水日数均有明显下降;夏季和秋季降水量和降水日数均减少,半干旱区夏季降水减少更明显,半湿润区则以秋季减少最为显著。北方地区年内发生的降水事件95%以上是小雨和中雨,小雨和中雨量总计占全年降水量的75%;研究时段内北方地区的小雨频率有不同程度下降,而中雨频率呈升高趋势,干旱区表现尤其明显,其对作物生长季内降水有效利用影响较小。各季节降水分配的变化中,干旱区和半干旱区春季降水贡献率升高,半湿润区秋季降水贡献率降低;干旱区仅夏季降水频率有下降;半干旱区各季节降水频率指标变动最突出,春冬季节降水频率有增加而夏秋季节降水频率在下降;半湿润区春季和冬季降水频率有所增加,而秋季降水频率下降;研究区域内各降水指标极大值主要集中南北两端;干旱区与半干旱区内北疆地区及内蒙古东北部的强降水量、强降水日数大于区域内青海、甘肃、宁夏的中部和南部。所得结论可为明确中国北方地区不同干湿区降水资源变化及种植结构和作物布局调整提供参考。     

华北石质山区杏树蒸腾规律和蒸降差分析

以河南省济源市石质山区8a生梯田杏树为例,利用热扩散植物液流技术（TDP）测算得到2005年和2006年杏树逐日蒸腾数据,结合同步观测的降水量数据,分析了华北石质山区杏树蒸腾耗水规律及水分供求关系,旨在为该地区节水杏园的发展提供依据。结果表明：（1）杏树蒸腾速率（TR）呈现出明显的日际变化特征,且在同一生长期内,晴天-多云日的蒸腾速率高于阴天。（2）从全年来看,4-8月杏树蒸腾速率相对其他月份要高,其中,5月（6月）蒸腾速率为全年最大时期;1月（12月）蒸腾速率为全年最低水平。（3）在华北石质山区,2005年和2006年的年际总降水量与杏树蒸腾耗水量差值分别为-263.25mm和-220.47mm,说明周年降水可以满足杏树蒸腾耗水的需要。但各月的蒸降差差异很大,7-9月降水量大于蒸腾量;其他大多月份降水不能满足杏树耗水的需要。     

The Chemical Composition of Precipitation in Madrid

The present study examines the chemical characteristics of first-fraction precipitation samples collected over a period of one year in Madrid, and patterns of temporal and spatial variation observed in their composition. One hundred and sixty-four samples of wet precipitation collected on an event basis were analysed for anions, cations, pH and electrical conductivity. Precipitation in Madrid was neutral, with only 3% of samples showing pH < 5.6. Dominant ions were calcium andsulphates. Calcium was the principal neutralizing agent, explaining 64% of all nitrates and sulphates. The marine influence did not appear to be relevant, while the soil seemed to play an important role in the composition of precipitation. Precipitation chemistry displayed seasonal differences, with higher concentrations of sulphates and chloride in autumn and winter and of calcium and sodium in the summer. There was an inverse relationship between concentrations and sample volumes; while the correlation between concentrations and the time elapsedsince the last rain event was positive, though poor for normalized concentrations. Four variables (sample volume, days elapsed since the last rain event, maximum wind gust direction and season) explained to a large extent (more than 90% for some sampling stations) the variability of certain chemical variables.     

Chemical Composition and Mineral Content of Common Vetch Seeds during Maturation

ABSTRACT

Common vetch (Vicia sativa L.) is an important legume cultivated for feed grain and forage in the Mediterranean and Central Asia regions. Little information is available about the changes in seed mass, chemical composition, and mineral concentration in the developing seeds of common vetch. Therefore, the objective of this experiment was to study the changes in seed mass, moisture content, fat, fiber, proteins, carbohydrates, reducing sugars, and macro- and microelements in common vetch seeds sampled at four pod developmental stages described based on pod color. Common vetch pods were harvested at four pod developmental stages: 1) full-size seed (FS), 2) greenish-yellow pods (GY), 3) yellow pods (Y), and 4) brown pods (B). Common vetch seeds attained maximum mass accumulation when pod color turned to yellow (the Y stage), which was a good indication of seed physiological maturity in common vetch. Results showed that ash, fat, fiber, protein, and carbohydrate content increased between the FS and GY stage. There was no significant change in the accumulation of these components at the Y stage as compared with the GY stage. During the desiccation phase (the Y to B stage), there was an increase in carbohydrate and reducing sugars and a decrease in proteins. Seed content (μg seed^?1) of macro- and microelements levels increased as the seed matured, reaching the maximum level by the GY stage [for phosphorus (P), sodium (Na), zinc (Zn), and manganese (Mn)], the Y stage [for copper (Cu)], and the B stage [for potassium (K) and iron (Fe)]. These results suggest that the majority of seed chemical composition was accumulated by the GY stage where farmers can harvest common vetch seed without reducing seed mass and nutrient loss. These data serve as a useful characterization of changes in chemical composition based on pod developmental stages for further studies.     

Effects of Salinity and Copper on Growth and Chemical Composition of Pistachio Seedlings

The effects of five salinity levels and four copper levels on growth and chemical composition of ‘Ghazvini, pistachio seedlings were studied under greenhouse conditions in a completely randomized design with three replications. Leaf area, stem height, shoot and root dry weights were determined on 24th week after planting. Copper (Cu), phosphorus (P), sodium (Na), and chlorine (Cl) total uptake in shoot and root of plant were measured. The results showed that salinity decreased growth parameters. Low levels of Cu application had no significant effect on leaf area, shoot and root dry weights while decreased stem height. The highest level of Cu (7.5 mg Cu kg^?1 soil) significantly increased leaf area and shoot dry weight but decreased stem height. Salinity decreased Cu and P uptake in the shoot and root, but increased total sodium and chloride uptake. Cu application increased shoot total P uptake and decreased root total Na uptake.     

密云水库北京集水区人工水源保护林降水化学性质研究

研究表明 ,密云水库集水区大气降水化学元素含量在不同时段内变幅较大 ,各元素加权平均值之和为12 .0 0 11m g/ L ,各元素含量大小排序为 Ca >N >K >Mg >Na >P >Fe>Zn >Cu >Mn。大气降水经过 3种类型的水源保护林林冠层后 ,所测定的化学元素含量变化不一 ,但总的结果来看 ,化学元素含量升高的元素较多 ,且化学元素含量之和 ,无论是林内穿透降雨还是树干茎流均呈升高趋势 ,不同林分结果如下 :林内穿透降雨中化学元素总量分别为刺槐林 4 6 .192 4 mg/ L、油松林 2 0 .6 135 m g/ L、板栗林 17.110 5 mg/ L ;树干茎流中化学元素总量不同林分分别为刺槐林 6 1.5 86 2 m g/ L、油松林 73.32 35 mg/ L、板栗林 35 .5 0 74 mg/ L。     

Chemical Composition of Precipitation, Throughfall and Soil Solutions at Two Forested Sites in Guangzhou, South China

Rain water at two forested sites in Guangzhou (south China) show high concentrations of SO₄ ^2?, NO₃ ^? and Ca²⁺ and display a remarkable seasonal variation, with acid rain being more important during the spring and summer than during the autumn and winter. The amount of acid rain represents about 95% of total precipitation. The sources of pollutants from which acid rain developed includes both locally derived and long-middle distance transferred atmosphere pollutants. The seasonal variation in precipitation chemistry was largely related to the increasing neutralizing capacity of base cations in rainwater in winter. Soil acidification is highlighted by high H⁺ and Al³⁺ concentrations in soil solutions. The variation in elemental concentration in soil solution was related to nitrification (H⁺, NH₄ ⁺ and NO₃ ^?) and cation exchange reaction (H⁺, Al³⁺) in soil. The negative effect of soil acidification is partly dampened by substantial deposition of base cations (Ca²⁺, Mg²⁺ and K⁺) in this area.     

Responses of Growth and Chemical Composition of Pistachio Seedling to Phosphorus Fertilization Under Saline Conditions

A greenhouse study was conducted to evaluate effects of phosphorus (P) levels (0, 50 and 100 mg kg^?1 soil) under saline (0, 1000 and 2000 mg sodium chloride (NaCl) kg^?1 soil) conditions on growth and chemical composition of pistachio seedlings (Pistacia vera L.) cv. ‘Badami-zarand’ in a completely randomized design (CRD) with four replications. Results showed that salinity application decreased leaf, stem, and root dry weights, number of leaf, length of stem and leaf area, while this effect diminished with P fertilization. By increasing salinity levels, all of the nutrients concentration in leaf, stem and root except sodium (Na) content were reduced. P application increased P and potassium (K) concentrations in the leaves, stem and root, while decreased Na and Zinc (Zn) leaf, stem and root concentrations. However, the results indicated that proline accumulation and reducing sugar content were increased by salinity, P and their interaction application. The results suggest that fertilization of phosphorus can diminish some adverse effects of high salinity on growth and chemical composition of pistachio seedlings.     

Soil Respiration of Biologically-Crusted Soils in Response to Simulated Precipitation Pulses in the Tengger Desert, Northern China

Soil respiration (SR) is a major process of carbon loss from dryland soils, and it is closely linked to precipitation which often occurs as a discrete episodic event. However, knowledge on the dynamic patterns of SR of biologically-crusted soils in response to precipitation pulses remains limited. In this study, we investigated CO₂ emissions from a moss-crusted soil (MCS) and a cyanobacterialichen-crusted soil (CLCS) after 2, 4, 8, 16, and 32 mm precipitation during the dry season in the Tengger Desert, northern China. Results showed that 2 h after precipitation, the SR rates of both MCS and CLCS increased up to 18-fold compared with those before rewetting, and then gradually declined to background levels; the decrease was faster at lower precipitation amount and slower at higher precipitation amount. The peak and average SR rates over the first 2 h in MCS increased with increasing precipitation amount, but did not vary in CLCS. Total CO₂ emission during the experiment (72 h) ranged from 1.35 to 5.67 g C m-² in MCS, and from 1.11 to 3.19 g C m-² in CLCS. Peak and average SR rates, as well as total carbon loss, were greater in MCS than in CLCS. Soil respiration rates of both MCS and CLCS were logarithmically correlated with gravimetric soil water content. Comparisons of SR among different precipitation events, together with the analysis of long-term precipitation data, suggest that small-size precipitation events have the potential for large short-term carbon losses, and that biological soil crusts might significantly contribute to soil CO₂ emission in the water-limited desert ecosystem.     

鳞盖红菇与正红菇成分分析及毒性实验

对鳞盖红菇（RussulalepidaFr）与正红菇（RussulavinosaLindbl）子实体的粗蛋白、水溶性粗多糖、微量元素、氨基酸等成分进行了分析、比较;并以正红苗为对照,对鳞盖红菇进行了急性毒性实验。结果表明：两种菇所测成分相近,且均属于安全食用菌。     

华北地区降水蒸发差与西太平洋副热带高压的关系

为揭示华北地区当代水资源受大气内部运动规律制约和海气相互作用的影响,采用小波相关和交叉小波变换方法,分析了华北地区降水蒸发差与西太平洋副热带高压脊线和北界位置变化的时频相关。结果表明,2000年以来华北南部的水资源短缺问题有所缓解,但以北京为中心的华北东北部仍处于持续缺水期;华北地区降水蒸发差与副高脊线及北界位置变化相关密切,存在年际和年代际尺度的显著相关振荡,与副高脊线的年代际尺度相关凝聚性最强;时域中年际尺度相关存在局部化特征,年代际尺度相关具有阶段性。分析认为,2000年以来副高脊线和北界位置偏北并维持反气旋型环流,有利于水汽向华北输送,使得华北降水增多成为近年来华北南部降水蒸发差增大的主要原因;而华北东北部仍处于持续缺水期,与东亚季风减弱不利于西南气流的水汽输送以及蒙古高原显著增暖导致蒸发增大等因素有关。副高强度和位置异常影响东亚季风强度和西风带槽脊位置引起华北降水和气温变化发生异常,对华北地区降水蒸发差的年际和年代际变化具有重要作用。     

Rapid Time Variations in Chemical Composition of Precipitation in South Korea

Data from a monitoring program on precipitation at four sites in South Korea during the period from 1993 to 1998 were analyzed for determining a time trend relationship in chemical composition of precipitation. The concentrations of nss-sulphate, ammonium and calcium were found to have decreased over time at a statistically significant level in Seoul (p<0.05). The concentration of nss-sulphate had declined by a rate of 12% per year for the period from 1993 to 1998. The concentrations of ammonium and calcium decreased by 11% and 12% per year respectively for the same period. The concurrent reduction of cation offsets the change in strong acid anion, thus the annual mean pH of precipitation has been approximately constant. In contrast to the rapid change of sulphate, the second most abundant anion, nitrate, showed no statistically significant decrease. As a result, the nitrate to nss-sulphate ratio (N/S ratio) has increased rapidly; the N/S ratio in precipitation has increased from less than 0.1 in 1985 to nearly 0.5 in 1998 at Seoul. In spite of the short monitoring period, a significant upward trend in the N/S ratio was also observed at all of the other sites suggesting that the nitrogen species contribute more to precipitation acidity throughout Korea.     

正红菇菌丝液体培养及其与子实体成分分析

正红菇（RussulavinosaLindbl）液体培养条件的筛选试验结果表明：选用1％葡萄糖、0．5％黄豆粉、0．1％KH2PO4,0.05％MgSO4.7H2O配制培养基,在pH6．2的条件下发酵6d,可达到最高菌丝产量2．989g/L。对正红茹子实体、液体培养所得菌丝体化学成分进行测定,结果表明：菌丝体的粗蛋白、氨基酸及微量元素的含量与子实体接近,但水溶性粗多糖的量只有子实体的1／10．     

Long-Term Trends in the Chemical Composition of Precipitation over Western Japan

Wet deposition monitoring was conducted at six rural stations in western Japan, during the period from 1987 through 1996. Long-term trends in the concentration of non-sea salt ions were analyzed on the basis of the data obtained. The monitoring results indicated that annual average concentrations of NO₃ ^? and NH₄ ⁺ in precipitation significantly increased on the order of 45%, and that of nss-Ca²⁺ and nss-SO₄ ^2?, concentrations did not change over the past 10 years. The ratio of NO₃ ^?/nss-SO₄ ^2? in precipitation significantly increased, the ratio of NO₃ ^?/NH₄ ⁺ showed no marked fluctuations, and the ratio of [nss-Ca²⁺+NH₄ ⁺]/[nss-SO₄ ^2?+NO₃ ^?] slightly increased during the period. These findings suggested that the wet deposition of NO₃ ^? and NH₄ ⁺ in western Japan, particularly that in the winter season, was influenced by the long-range transport of nitrogen oxides and ammonia from the Asian continent.     

平凉市纸坊沟小流域近50年径流对降水的响应分析

根据纸坊沟小流域1955—2002年降水、径流观测资料,采用时间序列分析法和统计回归分析法对降雨及径流的响应情况进行了分析,结果表明:降水量在年内分配不均,凸显单一峰值;降水在年际上呈平水年—干旱年—平水年（较丰水年）周期性变化;流域月径流变化基本与月降水量变化趋势相吻合,在同一周期中径流量峰值推后于降水量峰值一个时段,流域径流年变化幅度很大;径流深在季节分配上也有很大差异,主要集中在夏、秋季,占年总值的86.2%,而春、冬季仅占13.8%;径流距平值变化无论是季节上还是月度上均呈下降趋势;当年降水量增加或减小10%,20%,30%时,年径流深表现出分别增加或减少23.29%,46.59%,69.88%的正响应;随着时间的推移和流域治理程度的提高,流域径流量和径流深相应减小,径流深总体呈下降趋势。     

Investigation of Associations Between Rhizosphere Microorganisms and the Chemical Composition of Flue-Cured Tobacco Leaves Using Canonical Correlation Analysis

Canonical correlation analysis was applied to determine the relationship of rhizosphere microorganisms to common chemical components in flue-cured tobacco leaves. The results were as follows: (1) The chemical composition of the tobacco was related to the major microbial physiological groups in the rhizosphere soil. No close relationship was found with the populations of bacteria, fungi, and actinomycetes. (2) Greater contents of total nitrogen and potassium in tobacco leaves were associated with larger populations of aerobic nitrogen-fixing bacteria and with smaller populations of aerobic cellulose-decomposing bacteria. In addition, potassium content was also negatively correlated with nitrosobacteria counts but showed no close relationship with the potassium bacteria in the rhizosphere. The nicotine content was associated with greater populations of nitrosobacteria and nitrobacteria, and the content of water-soluble total sugar was positively correlated with the counts of nitrosobacteria.     

滇中地区降水特征与变化趋势研究

滇中地区是云南省政治、经济和文化与交通的中心,水资源短缺问题非常突出。以滇中地区1960—2011年13个气象站逐年降水量资料为基础,采用线性趋势、IDW空间插值、Mann-Kendall突变检验、Morlet小波分析等方法,对滇中地区50 a来降水变化特征与趋势进行了研究,结果表明:（1）滇中地区多年平均降水量为955.65 mm/a,波动于638.30~1627.60 mm之间,年降水量在空间分布上存在显著的区域差异,降水量大致呈现出由滇中中部向两侧逐渐递增的趋势;（2）50 a来,滇中地区降水量呈现减少趋势,速率为7.67 mm/10 a,且年降水量在2008年前后出现突变;（3）滇中地区降水量存在27 a和16 a左右的周期性变化,其中27 a时间尺度上的周期变化最显著,16 a时间尺度上局部特征突出;（4）滇中地区本来就是水资源匮乏区,降水量的减少趋势应该引起相关部门的重视。     

西北地区夏季降水的气候特征分析

利用西北地区119站1961-2000年夏季（6-8月）降水资料，统计分析了各站历年夏季降水的平均场、方差场和各年代际平均值分布特征与整体总量逐年平均值的年际和周期变化特点，结果表明：西北地区夏季降水可划分为3个基本气候分区，即北疆区、中西部盆地沙漠区和东部季风影响区。中西部盆地沙漠区降水量和降水量方差均最小，处于稳定的干旱状态；东部季风影响区降水量的方差变化较大，降水的不稳定性增加，干旱频率增大；北疆区降水量较大，变差处于另外两区之间，表明旱涝影响微弱。各区的降水量在不同年代际间也具有不同的特点，降水量的变化会直接影响到当地主要旱地作物的产量。     

Turkey Manure Ash Effects on Alfalfa Yield,Tissue Elemental Composition,and Chemical Soil Properties

A power plant that utilizes turkey manure as fuel to produce energy was built in Benson, Minnesota, and started full energy production in 2007. The plant was built to meet legislative requirements governing the use of renewable sources to generate energy in Minnesota. Although the use of turkey manure as biofuel generates energy, it also results in turkey manure ash (TMA) as a by‐product that contains phosphorus (P), potassium (K), sulfur (S), and zinc (Z) as well as other essential and nonessential elements. A 2‐year study was conducted to compare TMA with triple‐superphosphate and potassium chloride fertilizers as a source of nutrients for alfalfa (Medicago sativa) at three locations: Lamberton, Morris, and Appleton, Minnesota. The soils at Lamberton and Appleton were acidic with P and K concentrations ranging from medium‐high to very high, whereas the soil at Morris was alkaline with high concentrations of P and K. The experiment consisted of a control (0 P and 0 K) and annual and split applications of TMA and fertilizer. Annual TMA and fertilizer rates were 84 kg P₂O₅ ha^?1, 118 kg K₂O ha^?1, and 34 kg S ha^?1. Split rates were 42/42 kg P₂O₅ ha^?1, 59/59 kg K₂O ha^?1, and 17/17 kg S ha^?1. However, because of an overestimation of citrate‐soluble P in 2005 for the TMA, the total amount of available P applied with the TMA for the 2‐year study was 168 kg P₂O₅ ha^?1 compared with 286 kg P₂O₅ ha^?1 for the fertilizer. In the first year, fertilizer resulted in greater alfalfa biomass yield than TMA and the control, whereas in the second year, alfalfa yields with TMA and fertilizer were similar and both more than the control. In 2005, TMA resulted in more copper (Cu) and S tissue concentrations than the fertilizer. In 2006, application of both sources increased tissue P and S concentrations compared with the control. The TMA increased tissue Cu concentration and Zn plant uptake compared with fertilizer. Bray P1–extractable soil P concentrations were less with TMA and control treatments than with the fertilizer treatments. Ammonium acetate–extractable soil sodium (Na) concentrations were greater with TMA than with fertilizer and the control. By the second year, both ash and fertilizer treatments resulted in more K uptake than the untreated control with no difference in K uptake between the two sources or time of application. Both sources were effective in increasing P uptake compared with the untreated control. TMA was shown to be an effective source of nutrients for alfalfa production.     

西北黄土区降水资源综合调控利用基本理论和方式研究

总结西北黄土区自然环境基本特征和降水资源利用措施,针对天然降水时空分布特征和自然转化方式特点,提出了以人为调整降水自然转化方式类型组合为核心理念、以调整降水资源综合调控利用时间组合比和空间组合比为核心内容的基本理论和数学表达式,同时总结了以该理论为依据、以符合西北黄土区自然环境特征和社会经济特点为特色的降水资源综合调控利用基本方式,并列举相应典型事例证明其可行性。