Biomass and carbon stocks in three types of Persian oak (Quercus brantii var. persica) of Zagros forests in a semi-arid area,Iran

Persian oak (Quercus brantii var. persica) is a dominant tree species of Zagros forests in a semi-arid area, western Iran. However, the capacity of biomass and carbon stocks of these forests is not well studied. We selected three types of oak, i.e., seed-originated oak, coppice oak and mixed (seed-originated and coppice) oak of Zagros forests in Dalab valley, Ilam Province, Iran to survey the capacity of biomass and carbon stocks in 2018. Thirty plots with an area of 1000 m² were systematically and randomly assigned to each type of oak. Quantitative characteristics of trees, such as diameter at breast height (DBH), height, crown diameter and the number of sprouts in each plot were measured. Then, aboveground biomass (AGB), belowground biomass (BGB), aboveground carbon stock (AGCS) and belowground carbon stock (BGCS) of each tree in plots were calculated using allometric equations. The litterfall biomass (LFB) and litterfall carbon stock (LFCS) were measured in a quadrat with 1 m×1 m in each plot. One-way analysis of variance and Duncan's test were performed to detect the differences in biomass and carbon stocks among three types of oak. Results showed that AGB, BGB and BGCS were significantly different among three types of oak. The highest values of AGB, AGCS, BGB and BGCS in seed-originated oak were 76,043.25, 14,725.55, 36,737.79 and 7362.77 kg/hm², respectively. Also, the highest values of LFB and LFCS in seed-originated oak were 3298.33 and 1520.48 kg/hm², respectively, which were significantly higher than those of the other two types of oak. The results imply the significant role of seed-originated oak for the regeneration of Zagros forests. Further conservation strategy of seed-originated oak is an important step in the sustainable management of Zagros forests in Iran.     

哈萨克斯坦阿尔泰山树木径向生长及其对气候要素的响应

针对哈萨克斯坦阿尔泰山南坡西伯利亚云杉（Picea obovata）和西伯利亚落叶松（Larix sibirica）开展树轮研究，建立树轮年表，计算年平均树轮宽度值和年平均断面积生长量（BAI），并分析在1988年发生升温突变前后，这2个树种树轮宽度指数变化趋势，及其树木径向生长对气候因子的响应。结果表明：在升温突变前后，2个树种树轮宽度指数变化趋势一致。但是，在升温突变后，其变化趋势均由不显著增加转为显著下降。即树木径向生长减缓；升温突变后，2个树种树木径向生长对降水的响应有所减弱，而对气温的响应有所增强，并且发生了树轮指数和气候因子间相关性“正负转换”的情况。     

Characteristics of root pullout resistance of Caragana korshinskii Kom. in the loess area of northeastern Qinghai-Tibet Plateau,China

Roots exert pullout resistance under pullout force, allowing plants to resist uprooting. However, the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear. In this study, in order to improve our knowledge of pullout resistance characteristics of taproot systems of shrub species, we selected the shrub species Caragana korshinskii Kom. in different growth periods as the research plant and conducted in situ root pullout test. The relationships among the maximum pullout resistance, peak root displacement, shrub growth period, and aboveground growth indices (plant height and plant crown breadth) were analyzed, as well as the mechanical process of uprooting. Pullout resistance of 4-15 year-old C. korshinskii ranged from 2.49 (±0.25) to 14.71 (±4.96) kN, and the peak displacement ranged from 11.77 (±8.61) to 26.50 (±16.09) cm. The maximum pullout resistance and the peak displacement of roots increased as a power function (R²=0.9038) and a linear function (R²=0.8242) with increasing age, respectively. The maximum pullout resistance and the peak displacement increased with increasing plant height; however, this relationship was not significant. The maximum pullout resistance increased exponentially (R²=0.5522) as the crown breadth increased. There was no significant relationship between the peak displacement and crown breadth. The pullout resistance and displacement curve were divided into three stages: the initial nonlinear growth, linear growth, and nonlinear stages. Two modes of failure of a single root occurred when the roots were subjected to vertical loading forces: the synchronous breakage mode and the periderm preferential breakage mode. These findings provide a foundation for further investigation of the soil reinforcement and slope protection mechanisms of this shrub species in the loess area of northeastern Qinghai-Tibet Plateau, China.     

新疆山地针叶林乔木胸径-树高关系分析

树木的生长包括了径向生长和垂直生长两个方面,这两方面具有密切的关系,这一关系既受到树木本身的控制,同时也受森林立地条件的影响.通过分析新疆阿尔泰山、天山南北坡以及昆仑山区11个地点120个样方的胸径-树高关系.结果表明:昆仑山的尖削度(taper)显著大于其余3地,其潜在最大树高(potential height,H*...     

Dieback intensity but not functional and taxonomic diversity indices predict forest productivity in different management conditions: Evidence from a semi-arid oak forest ecosystem

The relationships between different aspects of diversity(taxonomic,structural and functional)and the aboveground biomass(AGB)as a major component of global carbon balance have been studied extensively but rarely under the simultaneous influence of forest dieback and management.In this study,we investigate the relationships between taxonomic,functional and structural diversity of woody species(trees and shrubs)and AGB along a gradient of dieback intensity(low,moderate,high and no dieback as control)under two contrasted management conditions(protection by central government vs.traditional management by natives)in a semi-arid oak(Quereus brantii Lindl.)forest ecosystem.AGB was estimated and taxonomic diversity,community weighted average(CWM)and functional divergence indices were produced.We found that the aerial biomass was significantly higher in the intensively used area(14.57(±1.60)t/hm²)than in the protected area(8.70(±1.05)t/hm²)due to persistence of some large trees but with decreasing values along the dieback intensity gradient in both areas.CWM of height(H),leaf nitrogen content(LNC)and leaf dry matter content(LDMC)were also higher in the traditional managed area than in the protected area.In contrast,in the protected area,the woody species diversity was higher and the inter-specific competition was more intense,explaining a reduced H,biomass and LDMC.Contrary to the results of CWM,none of the functional diversity traits(FDvar)was affected by dieback intensity and only FDvar values of LNC,leaf phosphorus content(LPC)and LDMC were influenced by management.We also found significantly positive linear relationships of AGB with CWM and FDvar indices in the protected area,and with taxonomic and structural diversity indices in the traditional managed area.These results emphasize that along a dieback intensity gradient,the leaf functional traits are efficient predictors in estimating the AGB in protected forests,while taxonomic and structural indices provide better results in forests under a high human pressure.Finally,species identity of the dominant species(i.e.,Brant’s oak)proves to be the main driver of AGB,supporting the selection effect hypothesis.     

对葱黄寡毛跳甲高毒力Bt菌株的鉴定及效果评价

本研究筛选到一株对葱黄寡毛跳甲具有较高杀虫活性的菌株DK49，利用菌株DK49 gyrB基因序列和phoR基因序列分别在GenBank中进行同源性比较，两种基因序列均与苏云金芽胞杆菌的相应基因序列同源性最高，达到99%；同时分别构建系统发育树，发现菌株DK49均与苏云金芽胞杆菌聚合在一起，说明菌株DK49属于苏云金芽胞杆菌。Biolog表型分析结果显示菌株DK49可有效利用14种碳源，对二甲胺四环素等10种化学物质敏感，对利福霉素等11种化学物质不敏感。通过室内生物活性评价，明确菌株DK49对葱黄寡毛跳甲成虫3 d的LC₅₀为0.8161×10⁷ cfu/mL。田间小区结果显示，菌株DK49在1×10⁷ cfu/mL浓度下，连续施药3次后对葱黄寡毛跳甲的虫口减退率达到92.31%，防治效果达到96.81%。可见，菌株DK49能有效地控制葱黄寡毛跳甲的发生为害，具有良好的应用前景。     

西天山雪岭云杉林分密度对森林生物量分配格局和异速生长的影响

雪岭云杉林是新疆天山北坡山地森林中广泛分布的优势种,探讨林分密度对天山雪岭云杉林器官生物量分配格局和树高-胸径异速生长的影响,对于阐明雪岭云杉林生物量在不同环境中的适应具有重要意义。通过分析在不同林分密度(≤300株·hm^-2、300~450株·hm^-2、450~600株·hm^-2、>600株·hm^-2)下雪岭云杉林(Picea schren?kiana)的生长特性,研究林分密度对雪岭云杉林器官生物量分配格局及树高-胸径异速生长的影响。结果表明,随着林分密度增加,雪岭云杉林各器官平均生物量均降低;树干和树根生物量占比增加,树枝生物量占比减少,树叶和树皮生物量占比变化不显著;雪岭云杉林树高和胸径均随林分密度的增加而降低。此外,雪岭云杉林树高(H)和胸径(D)间具有显著的异速生长关系,其中树高-胸径(H-D)的最优异速生长方程为:y=2.312×x^0.900(R²=0.761,P<0.01);随着林分密度增加,雪岭云杉林lgH-lgD呈现出复杂非线性异速生长关系,该关系的显著性受林分密度变化呈现逐渐降低的趋势,这表明林分密度通过雪岭云杉林对生长资源的竞争影响各器官的生长发育。研究结果可为雪岭云杉林的可持续经营与管理提供理论依据和数据支撑。     

Soil microbial activity and community structure as affected by exposure to chloride and chloride-sulfate salts

Mixed or chloride salty ions dominate in saline soils, and exert wide-ranging adversely affect on soil biological processes and soil functions. The objectives of this study were to(1) explore the impacts of mixed(0, 3, 6, 10, 20 and 40 g Cl~–/SO_4~(2–)salt/kg dry soil) and chloride(0, 1.5, 3, 5, 8 and 15 g Cl~– salt/kg dry soil) salts on soil enzyme activities, soil physiological functional(Biolog) profiles and microbial community structure by using soil enzymatic, Biolog-Eco microplates as well as denaturing gradient gel electrophoresis(DEEG) methods, and(2) determine the threshold concentration of soil electronic conductivity(EC_(1:5)) on maintaining the functional and structural diversity of soil microbial community. The addition of either Cl~– or mixed Cl~–/SO_4~(2–)salt obviously increased soil EC, but adversely affected soil biological activities including soil invertase activity, soil microbial biomass carbon(MBC) and substrate-induced respiration(SIR). Cl~– salt showed a greater deleterious influence than mixed Cl~–/SO_4~(2–)salt on soil enzymes and MBC, e.g., the higher soil MBC consistently appeared with Cl~–/SO_4~(2–)instead of Cl– treated soil. Meanwhile, we found that SIR was more reliable than soil basal respiration(SBR) on explaining the changes of soil biological activity responsive to salt disturbance. In addition, microbial community structures of the soil bacteria, fungi, and Bacillus were obviously affected by both salt types and soil EC levels, and its diversity increased with increasing of mixed Cl~–/SO_4~(2–)salt rates, and then sharply declined down after it reached critical point. Moreover, the diversity of fungal community was more sensitive to the mixed salt addition than other groups. The response of soil physiological profiles(Biolog) followed a dose-response pattern with Cl~–(R~2=0.83) or mixed Cl~–/SO_4~(2–)(R~2=0.89) salt. The critical threshold concentrations of salts for soil physiological function were 0.45 d S/m for Cl~– and 1.26 d S/m for Cl~–/SO_4~(2–), and those for soil microbial community structural diversity were 0.70 d S/m for Cl~– and 1.75 d S/m for Cl~–/SO_4~(2–).     

Prioritizing woody species for the rehabilitation of arid lands in western Iran based on soil properties and carbon sequestration

Plants are an important component in many natural ecosystems. They influence soil properties, especially in arid ecosystems. The selection of plant species based on their adaptations to site conditions is essential for rehabilitation of degraded sites and other construction sites such as check-dams. Other factors to be considered in species selection include their effects on soil properties and their abilities to meet other management objectives. The purpose of this study was to assess the effects of native (Populus euphratica Oliv. and Tamarix ramosissima Ledeb.) and introduced (Eucalyptus camaldulensis Dehnh. and Prosopis juliflora (Swartz) DC.) woody species on soil properties and carbon sequestration (CS) in an arid region of Iran. Soil sampling was collected at three soil depths (0-10, 10-20 and 20-30 cm) at the sites located under each woody species canopy and in an open area in 2017. Soil physical-chemical property was analyzed in the laboratory. The presence of a woody species changed soil characteristics and soil CS, compared with the open area. For example, the presence of a woody species caused a decrease in soil bulk density, of which the lowest value was observed under E. camaldulensis (1.38 g/cm³) compared with the open area (1.59 g/cm³). Also, all woody species significantly increased the contents of soil organic matter and total nitrogen, and introduced species had more significant effect than native species. The results showed that CS significantly increased under the canopy of all woody species in a decreasing order of P. euphratica (9.08 t/hm²)>E. camaldulensis (8.37 t/hm²)>P. juliflora (5.20 t/hm²)>T. ramosissima (2.93 t/hm²)>open area (1.33 t/hm²), thus demonstrating the positive effect of a woody species on CS. Although the plantation of non-native species had some positive effects on soil properties, we recommend increasing species diversity in plantations of native and introduced woody species to provide more diversity for the increased ecosystem services, resilience, health and long-term productivity.     

蒙古蒿挥发油对三种主要枸杞害虫的控制作用

为保障枸杞产品质量安全,采果期不受化学农药干预,本研究通过室内毒力测定和田间药效试验评价了蒙古蒿挥发油的杀虫活性。结果表明,蒙古蒿挥发油对棉蚜的LC₅₀为7.82mg/mL;对枸杞木虱的LD₅₀为2.89μg/头;对西花蓟马的LC₅₀为2.80mg/mL,均低于对照药剂印楝素提取物,其中胡椒酮、PPG2-甲醚和桉油烯醇起主要杀虫作用。利用响应面分析,蒙古蒿挥发油制备成8.5%蒙古蒿挥发油微胶囊剂,该制剂在质量浓度6kg/hm²条件下,药后1d,对枸杞蚜虫、西花蓟马和枸杞木虱的防效分别为75.95%、58.81%和32.14%,高于对照0.3%印楝素乳油,杀虫效果一直持续到21d。本研究将蒙古蒿挥发油微胶囊应用于枸杞园采果期防治主要害虫,持效期长,具有进一步开发成高效植物源农药的潜力。     

崇左甘蔗螟虫种群动态及螟黄赤眼蜂防治效果评价

本文阐明了崇左甘蔗螟虫发生规律和探索利用螟黄赤眼蜂防治蔗螟的田间效果,为应用该天敌控制螟虫危害提供参考。在崇左市龙州县连续两年开展了甘蔗螟虫人工合成性诱剂诱集成虫,监测其种群动态和释放螟黄赤眼蜂防治蔗螟的田间试验。结果表明,在崇左市诱集到的甘蔗螟虫种类以条螟和二点螟为主,黄螟少;2016年条螟成虫高峰期分别在3月下旬、5月下旬、7月中旬和8月下旬,2017年条螟成虫的高峰期在3月中旬、5月中旬、6月中旬和8月中旬;而二点螟主要诱集到第1代成虫,2016和2017年二点螟第1代成虫的高峰期分别在4月中旬和3月中旬,其他时期诱蛾数量少。释放螟黄赤眼蜂两年后,甘蔗田螟虫造成的枯心苗率和死尾率均控制在1.56%～8.76%,螟害节率控制在4.45%～7.39%,两年平均挽回产量和减少损失为15194.4 kg/hm²和18.68%,糖分含量增加1.18%～2.25%,甘蔗产糖量增加3529.9～3879.3 kg/hm²,可挽回蔗农经济损失7293.31元/hm²,平均每公顷可增加纯收入6873.25元。本研究表明释放螟黄赤眼蜂对甘蔗螟虫的田间防治效果和经济效益较显著。     

四种杀虫剂对七星瓢虫和松毛虫赤眼蜂的负效应

七星瓢虫Coccinella septempunctata Linnaeus和松毛虫赤眼蜂Trichogramma dendrolimi Matsumura作为多种害虫的天敌昆虫，广泛应用于生物防治中。本研究按标准采用药膜法分别测定了37%联苯·噻虫胺悬浮剂、24%溴虫腈·甲维盐悬浮剂、45%吡虫·虫螨腈悬浮剂和20%甲维盐·茚虫威悬浮剂四种杀虫剂对七星瓢虫2龄幼虫和松毛虫赤眼蜂成蜂的急性接触毒性，并进行了安全性评价。结果表明：37%联苯·噻虫胺悬浮剂、24%溴虫腈·甲维盐悬浮剂、45%吡虫·虫螨腈悬浮剂和20%甲维盐·茚虫威悬浮剂对七星瓢虫的LR₅₀分别为0.0327、6.90、5.00和1.25 g a.i./hm²，其中24%溴虫腈·甲维盐悬浮剂对七星瓢虫为高风险性，其余药剂为极高风险；对赤眼蜂的LR₅₀分别为2.35×10^-3、0.0129、6.46×10^-3和0.127 g a.i./hm²，均属极高风险。本研究为杀虫剂对七星瓢虫和松毛虫赤眼蜂的负效应影响研究提供一定数据支持。     

设施番茄连作障碍土壤修复及其对青枯病害的防治效果

连作障碍的土壤修复是世界性难题。本研究利用土壤微生态修复剂结合青枯病植物疫苗菌剂来改良土壤和预防青枯病发生。在连作7年的番茄地,设3种处理,处理1为添加量60 t/hm²的土壤微生态修复剂和植物疫苗100倍稀释液,处理2为添加量30 t/hm²的土壤微生态修复剂和植物疫苗100倍稀释液,CK为不添加土壤微生态修复剂和植物疫苗,研究不同处理对连作番茄土壤养分、土壤酶活性、植株生长特性及病害防效的影响。结果表明,土壤微生态修复剂2种不同添加量处理的番茄土壤有机质、全氮、全磷和交换性钙含量均显著高于对照,而全钾含量显著低于对照;两种不同添加量处理的番茄土壤过氧化氢酶、脲酶、蔗糖酶和酸性磷酸酶活性均显著高于对照,添加量为30 t/hm²处理的土壤各酶活性（酸性磷酸酶除外）大于添加量为60 t/hm²处理的土壤;添加30 t/hm²处理的单果重量（113.82 g）显著高于添加量60 t/hm²处理（104.07 g）和对照处理（104.99 g）（P<0.05）,其对番茄青枯病防效达91.87%,大于添加量为60 t/hm²处理的防效（55.34%）。     

蠼螋捕食草地贪夜蛾的行为及功能反应

为明确蠼螋对草地贪夜蛾的捕食作用,在温度（26±1）℃,相对湿度（75±5）%,光周期16L：8D的实验室条件下,观察了蠼螋5龄若虫对草地贪夜蛾卵、1~6龄幼虫和成虫的捕食行为和对6龄幼虫的捕食功能反应。结果表明：蠼螋5龄若虫对草地贪夜蛾卵和1~6龄幼虫均有捕食行为,对飞行能力弱的草地贪夜蛾成虫也具有捕食能力。蠼螋5龄若虫对草地贪夜蛾捕食过程中,并不取食完其整个虫体,而是咬食至猎物不动时,继续搜索捕食周围其他猎物。蠼螋5龄若虫对草地贪夜蛾6龄幼虫的捕食功能拟合HollingⅡ模型,日平均捕食量为2.85头,对入侵的草地贪夜蛾的为害具有一定的防控潜能。     

茄匍柄霉菌实时荧光定量PCR检测方法的建立及应用

 为了准确检测病残体内茄匍柄霉菌(Stemphylium solani)DNA含量在土壤内的动态变化,本研究根据三磷酸甘油醛脱氢酶(GAPDH)基因序列,设计并筛选特异性引物Stem-g7F/Stem-g7R,能从靶标基因组 DNA 中特异性扩增出大小为 150 bp 的目的片段。建立的Stemphylium solani实时荧光定量PCR(Real-time quantitative PCR, qRT-PCR)检测体系的灵敏度比常规 PCR 高 1 000 倍,且特异性良好。标准曲线循环阈值与模板浓度呈良好的线性关系,相关系数为 0.992。利用所建立的qRT-PCR方法对病残体进行检测发现,病残体DNA初始拷贝数为3.69 × 10⁹ 拷贝数/g,经过温度27℃、80%湿度下处理30 d病残体DNA含量下降至1.21 × 10⁶ 拷贝数/g,而在温度27℃、20%湿度下含量为1.29 × 10¹⁰ 拷贝数/g。因此,建立的S. solani的qRT-PCR检测体系具有特异性强、灵敏度高的特点,可以快速准确地定量检测病残体 S. solani 的含量,为番茄匍柄霉叶斑病的早期预防和流行监测提供有效的技术手段。     

新疆山地针叶林植物物种组成与丰富度研究

通过对新疆阿尔泰山、天山北坡、天山南坡和昆仑山西部11个地点122个样方的调查,发现阿尔泰山针叶林植物(包括乔木、灌木和草本)丰富度显著高于天山南坡和昆仑山;天山南坡和昆仑山物种组成相似,阿尔泰山和天山北坡物种组成相似.全疆针叶林物种丰富度随年平均气温和海拔的增加显著下降,随纬度的升高显著升高.在不同区域,物种丰富度随...     

Exploring tree diversity and stand structure of savanna woodlands in southeastern Sudan

Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots (1000 m² for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height (DBH) ≥5.00 cm were identified and counted, and their DBH values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species (Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm² and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities.     

水稻二化螟病原真菌鉴定及其致病力

通过对吉林本地自然越冬代罹病的水稻二化螟幼虫进行分离纯化，筛选出两个病原真菌JL003和JL005，采用形态特征比较和rDNA-ITS序列构建系统树进行分析，并采用浸渍法研究了2个菌株对二化螟3龄和6龄幼虫的毒力作用。鉴定结果表明，菌株JL003和JL005分别为渐狭蜡蚧菌和球孢白僵菌，其中，渐狭蜡蚧菌侵染水稻二化螟为国内新近报道。致病力研究结果表明，渐狭蜡蚧菌JL003对二化螟3龄和6龄幼虫的致死率为53.0%和46.0%，球孢白僵菌JL005对3龄和6龄幼虫的致死率为94.0%和93.0%。对低龄和高龄二化螟幼虫，菌株JL005对二化螟的致死率均明显好于菌株JL003，表现出更大的生物防治潜能。     

利用微生物杀菌剂防治马铃薯黄萎病

马铃薯黄萎病是一种重要的世界性土传兼种传维管束病害，危害大且防治困难。利用活体微生物杀菌剂是防治作物土传病害的有效措施之一。本研究通过盆栽试验评价了微生物杀菌剂枯草芽胞杆菌可湿性粉剂对马铃薯出苗和生长的安全性，在河北省马铃薯主产区开展田间小区试验，研究了该制剂有效防治马铃薯黄萎病的使用方法和适宜施用剂量，并在河北省涞源县、围场县和永年区3县区分别开展了田间示范应用。盆栽试验和田间试验结果表明，枯草芽胞杆菌可湿性粉剂15、30和45 kg/hm²拌种处理对马铃薯出苗安全，对马铃薯生长没有不良影响；田间小区试验表明，在围场县试验田中，该制剂30 kg/hm²拌种处理单独使用或30 kg/hm²拌种加15 kg/hm²初花期滴灌使用均能显著减轻马铃薯黄萎病的发生，分别增产15.53%和17.10%；在新乐市试验田，枯草芽胞杆菌可湿性粉剂30 kg/hm²拌种处理显著增加马铃薯产量16.38%。田间示范应用结果表明，枯草芽胞杆菌可湿性粉剂30 kg/hm²拌种处理在涞源县和围场县防治马铃薯黄萎病效果显著，防效分别为84.22%和72.93%，两地分别显著增产24.30%和9.27%；在邯郸市永年区，相比化学药剂对照处理，枯草芽胞杆菌可湿性粉剂30 kg/hm²拌种处理显著增加马铃薯产量19.73%。本研究表明，枯草芽胞杆菌可湿性粉剂对马铃薯黄萎病具有显著的防治效果和显著的增产效果，为该制剂在马铃薯生产中高效应用提供了科学依据。     

Reconstruction of hydrological changes based on tree-ring data of the Haba River,northwestern China

Reconstructing the hydrological change based on dendrohydrological data has important implications for understanding the dynamic distribution and evolution pattern of a given river. The widespread, long-living coniferous forests on the Altay Mountains provide a good example for carrying out the dendrohydrological studies. In this study, a regional composite tree-ring width chronology developed by Larix sibirica Ledeb. and Picea obovata Ledeb. was used to reconstruct a 301-year annual(from preceding July to succeeding June) streamflow for the Haba River, which originates in the southern Altay Mountains, Xinjiang, China. Results indicated that the reconstructed streamflow series and the observations were fitting well, and explained 47.5% of the variation in the observed streamflow of 1957–2008. Moreover, floods and droughts in 1949–2000 were precisely captured by the streamflow reconstruction. Based on the frequencies of the wettest/driest years and decades, we identified the 19 th century as the century with the largest occurrence of hydrological fluctuations for the last 300 years. After applying a 21-year moving average, we found five wet(1724–1758, 1780–1810, 1822–1853, 1931–1967, and 1986–2004) and four dry(1759–1779, 1811–1821, 1854–1930, and 1968–1985) periods in the streamflow reconstruction. Furthermore, four periods(1770–1796, 1816–1836, 1884–1949, and 1973–1997) identified by the streamflow series had an obvious increasing trend. The increasing trend of streamflow since the 1970s was the biggest in the last 300 years and coincided with the recent warming-wetting trend in northwestern China. A significant correlation between streamflow and precipitation in the Altay Mountains indicated that the streamflow reconstruction contained not only local, but also broad-scale, hydro-climatic signals. The 24-year, 12-year, and 2.2–4.5-year cycles of the reconstruction revealed that the streamflow variability of the Haba River may be influenced by solar activity and the atmosphere–ocean system.