东阿拉善自然保护区天然梭梭林鼠害防治技术

对东阿拉善自然保护区天然梭梭林害鼠种类、密度、危害情况进行调查,并进行人工地面防治试验和飞机防治试验。从调查结果可看出天然梭梭林害鼠种类有20种,以大沙鼠为优势种,春季危害严重,秋季次之。试验结果表明:C型肉毒素(1∶80∶1000)防治效果最佳,并且成本较低,饵料选择为胡萝卜,投药方法为洞口投药,投药时间为每年为3~4月份;飞机防治试验没有取得理想效果。     

贝奥雄性不育灭鼠剂防治两种害鼠试验

贝奥雄性不育灭鼠剂防治棕背Clethrionomys rufocanus和大沙鼠Rhombomys opimus试验表明,防治棕背采用1次投药11.25 kg/hm2,防治效果达83%以上;防治大沙鼠用"贝奥"母粉与饵料(胡萝卜+香油)1.25∶1 000配制为推荐量。     

林鼠毒饵饵料选择及毒饵包装试验

农田鼠、卫生鼠防治多用大米、小麦及其加工品作为毒饵的饵料.过去,我省从东北购进林鼠毒饵以谷子、小麦等为饵料.这些毒饵都未经包装,不防雨,易潮,易霉变,投药也不方便.林鼠危害多发生在我省盆周山间、高山林区.其特点是多雨,分散,交通不便,坡陡,杂灌茂密,投药困难.为适应林鼠防治特点.1989年12月在安县高川乡林场两岔河林区作了毒饵饵料选择及毒饵包装试验.     

中华鼢鼠化学防治初探

通过4种药剂,3种饵料对中华鼢鼠的防治对比研究,结果表明:防治药剂以溴敌隆、杀鼠醚效果较好,饵料以洋葱和小麦较好,建议推广应用在洞内1次投放溴敌隆小麦毒饵.     

2种植物源药剂对松丽毒蛾幼虫应用效果

为明确1.3%苦参碱可溶液和1.2%烟碱·苦参碱乳油喷烟防治松丽毒蛾幼虫的林间最佳配比和用药量,在三明市三元区岩前镇、莘口镇的马尾松林建立试验区开展林间防治试验。结果表明:药后3 d,施用2种药剂的松丽毒蛾幼虫死亡率达85.6%以上,1.3%苦参碱可溶液和1.2%烟碱·苦参碱乳油2种药剂与烟雾剂最佳配比均为V(药剂)︰V(烟雾剂)=1︰9,林间最佳用药量分别为750 mL/hm^(2)和600 mL/hm^(2)。2种植物源药剂喷烟防治松丽毒蛾幼虫均有良好效果。     

撑绿竹长足竹大象防治技术

近年来,在广西等地的撑绿竹林中爆发了大面积的长足竹大象虫害,其危害之大,已经严重影响了当地撑绿竹产业的发展,也制约了该竹种的大面积推广与应用。为了有效防治该虫害,文中以近年来广西区爆发的长足竹大象虫害为研究对象,采用不同药剂种类(A)、施药方法(B)、药剂浓度(C)及施药次数(D)等防治手段,用感虫率和感虫指数作为虫害控制效果的考核指标,就不同药剂处理对虫害的控制效果进行了连续3年的试验研究。结果表明:对该虫害控制效果较好的药剂为A2(赣竹药Ⅰ+粒粒金+锐劲特)和A1(杀虫双+万金丰+氧化苦参碱);最适药剂浓度为C1水平,即600倍;最适用的施药方法为B3(蔸部土壤+喷雾)和B1(竹腔注射+竹基节削青涂抹+蔸部土壤);最佳施药次数为D4,即5次。     

应用溴敌隆和大隆母液防治高原鼢鼠田间试验

采用0.5%溴敌隆母液(A号)和0.5%大隆母液(B号),利用小麦为饵料,与原药按1:70的比例配制成(A1和B1)毒饵,掺加丘氏专用诱鼠剂配制成(A2和B2)毒饵,掺加白糖、菜子油和新鲜葱末配制成(A3和B3)毒饵,在高原鼢鼠的有效洞口内投药,10d后的平均死亡率分别为A1:66.04%、A2:86.57%、A3:94.11%、B1:61.89%、B2:84.02%、B3:88.63%。经方差分析表明,药物溴敌隆的效果比大隆的效果显著;利用小麦与白糖,清油,新鲜葱配成的毒饵对高原鼢鼠的引诱效果比邱氏诱鼠剂毒饵效果显著,并且成本低。     

国槐药物疏花疏果技术

采用科学方法对萘乙酸、乙烯利、多效唑三种药剂试验分析,得到浓度为(8×10-5)的萘乙酸对国槐脱蕾效果好、树体外在表现佳、促进国槐生长量大、耗费药剂成本低,是国槐疏花疏果的最佳方案。       

不同防治方法对核桃腐烂病防治效果研究

近年来,受地理位置和环境变化等因素影响,辽宁省核桃腐烂病发生较为严重。为筛选出防治核桃腐烂病的有效方法,采取不同药剂及不同病斑处理方式对核桃腐烂病进行防治,结果表明,不同药剂防治效果为菌毒清退菌特护树将军甲基硫菌灵石硫合剂;不同新型药剂使用3种处理方法的防治效果为方法2方法1方法3,方法2即对病斑进行划痕后再施药的处理方法最佳,既能发挥药剂效果,又能阻碍传染扩散,果实产量也最佳。     

昆虫标本害虫小圆皮蠹防治初报

对小圆皮蠹(Anthrenus verbasci)主要生活习性观察发现,该虫在陕西关中1年1代,主要以幼虫危害昆虫标本,轻者使标本受损,重者使标本彻底毁坏。进行不同时间,不同投药方法防治试验,发现6月上旬,以柜顶、柜子中层投药效果好。     

Armillaria ostoyae in managed coniferous forests in Kastamonu in Turkey

Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m². One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites.     

上海中央公园特大银杏树白蚁防治探讨

通过对上海松江中央公园内65株特大银杏树白蚁为害情况的调查,发现该公园银杏受害率为100%,其中存在活白蚁的银杏占总量的56.9%,采用毒土处理、粉剂疗法、建立白蚁监测点等措施,经过两次灭杀,活白蚁的灭杀率达到92.3%和93.3%,从而使存在活白蚁银杏树的比例从56.9%下降到2.7%,白蚁发生情况明显降低。       

我国食品中农药残留研究进展

随着人们安全健康意识提高,食品中农药残留问题更加受到重视,本文综述了样品预处理研究进展及农药残留快速检测技术研究进展,并简单分析介绍各种方法的优缺点。     

建平半干旱地区石质山地造林技术研究

研究了不同植物在石质山地的造林成活率、土壤化学性质随造林年限的变化和造林措施对土壤化学性质和植物胸径、树高年净生长量的影响。结果表明：不同植物在石质山地的成活率在21%～85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右;植被能明显提高石质山地不同土层的有机质、全N、P2O5含量,但提高程度随土层深度、养分种类和造林年限的不同而不同;在同一土层,生物复合肥料、菌剂和保水剂均显著提高土壤有机质含量（p〈0.01）并显著降低土壤P2O5含量（p〈0.01）;只有保水剂可引起土壤全K含量的明显升高;生物复合肥料、菌剂和保水剂均显著提高白榆、小叶杨、刺槐、栾树树高和胸径的年净生长量,但保水剂的提高程度最高。     

植物DNA甲基化研究进展

植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。     

木材碳封存研究进展

碳封存可以分工业封存和生物封存, 工业封存包括地质封存、海洋封存、矿石碳化以及工业循环利用, 这些方法能快速回收CO₂, 但工艺流程技术复杂, 成本较高。木材碳封存是生物碳封存的一种类型, 树木光合作用吸收的碳主要存贮在木材中。运用木材密度、微密度等检测仪器, 通过确定木材密度变化, 结合其含碳率来计量木材的碳封存过程以及封存过程中碳的分配格局, 同时研究其与环境因子的相关性, 可以为研究森林的碳吸收动态提供便捷的方法和科学的依据。     

Natural regeneration in patch clear-cutting in Picea abies stands in Southern Finland

Abstract

The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha^–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha^?1), and 36% were at least satisfactory (≥1300 ha^?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting.     

Tree regeneration in patch cutting in Norway spruce stands in northern Finland

The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37?ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000?ha^?1, of which 1700?ha^?1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100?ha^?1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches.     

Changes in micropores in dry wood with elapsed time in the environment

To investigate the changes in microstructures of wood with elapsed time in the environment, CO₂ adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years. The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption and/or temperature variation in the environment.