间伐对油松人工林碳储量的长期影响

间伐不仅能改变人工林林木生长状况,还会影响整个森林碳储量,研究间伐对人工林碳固存的长期影响,有助于准确评价人工林的碳汇功能,为人工林的科学经营管理提供参考。2016年8月,以黄土高原森林区营造于1962年,间伐于1985年的4种(强度间伐、中度间伐、轻度间伐、对照)油松人工林为对象,保留密度分别为800,1 500,2 200,2 900株/hm~2,研究了间伐对油松人工林不同植被层、叶凋落物、粗木质残体和土壤有机碳库的影响。结果表明:轻度和中度间伐下油松人工林系统碳储量较对照显著提高了28.54%和21.33%,强度间伐碳储量(154.66t/hm~2)与对照(169.26t/hm~2)无显著差异。乔木层是油松人工林的主要碳库,占人工林总碳储量的64.85%~74.62%。不同处理下乔木层树干碳储量所占比例最高(52.05%~56.43%),树根和树枝次之(22.27%~22.60%和17.73%~18.32%),树叶最低(3.56%~7.01%)。中度和强度间伐下在提高林下灌草多样性的同时,总的灌草碳储量分别比对照高24.27%和25.24%。间伐显著降低了叶凋落物碳储量,其中,强度间伐下的叶凋落物只有对照的48.15%。土壤碳库的变化主要是由土壤表层0—20cm有机碳变动所引起,中度和强度间伐土壤表层碳储量较对照分别减少了17.68%和33.76%,而轻度间伐(51.23t/hm~2)与对照(50.96t/hm~2)无显著差异。土壤表层碳储量与植物多样性和基础呼吸呈显著负相关。轻度和中度间伐有助于森林生态系统碳固定,其中轻度间伐不仅有利于地上植被碳固定,而且还有助于土壤碳库的维持。     

当归麻口病防治农药组合筛选

在当归主产区甘肃省岷县闾井镇草地村,开展了当归麻口病的发生率调查及其不同药剂组合的筛选试验。结果表明,引起当归麻口病的腐烂茎线虫在0~5cm土层中虫口密度最大,占总虫数的57.12%;不同农药组合对当归麻口病都有一定的防效,其中53.8%的氢氧化铜水分散粒剂+3%阿维菌素乳油复配剂1 000倍液的防治效果最好,防效达到73.56%;当归产量比对照增加了3 076.54kg/hm~2,增产率达29.4%,建议在当归主产区大面积推广应用。     

Crop type and altitude are the main drivers of species composition of arable weed vegetation in Tajikistan

The influence of broad‐scale environmental factors on the species composition of segetal weed communities in Tajikistan was investigated. The research was conducted throughout the country, analysing plots of root crops as well as cereals from all phytogeographical regions of Tajikistan, with the exception of the eastern Pamir. The study was based on 440 phytosociological relevées sampled between 2009 and 2013 and analysed using direct and indirect ordinations. A set of environmental variables was obtained for each plot: altitude, mean annual precipitation, mean annual temperature, pH, crop type, longitude, latitude and date of sampling (seasonality). Crop type was the major factor determining species composition, which was related to the different farming practices in roots and cereals. Major changes in weed species composition were also driven by altitude and correlated temperatures. The seasonality of weed communities also had a considerable effect on weed community structure. Samples from spring differed significantly from samples from summer and late summer. Only longitude and soil pH were found to be insignificant. The complete set of environmental variables used in a canonical correspondence analysis explained 8.3% of the species variation in sampled plots. The study showed that despite the very diverse climatic conditions and low intensity of agriculture in Tajikistan, agrocoenoses respond mainly to the type of cultivation practised in arable land.     

渭北旱塬区典型农业耕作土壤微形态分形研究

利用分形几何的方法,对渭北旱塬典型旱作农业土壤微形态的分形特征进行了研究.在对土壤薄片详细观察的基础上,以土壤微形态数字图像为基础,利用SISC IAS V8.0 软件提取了土壤孔隙与粗颗粒的有关参数,并用计盒维数法计算了其分形维数.结果表明,土壤孔隙分形维数与孔隙率、孔隙面积和周长呈现较好的相关性(依次为0.778 74,0.685 58,0.814 87),粗颗粒分形维数与粗颗粒的含量、面积和周长也呈现较好的相关性(相关系数依次为0.984 18,0.984 06,0.930 10).说明了利用土壤微形态获得的土壤分形维数能够反映土壤结构的空间分布和变异规律,也反映了农业耕作活动对土壤的影响.     

A retrospective analysis of radiation therapy for the treatment of feline vaccine‐associated sarcoma*

We retrospectively evaluated predictive prognostic factors in 73 cats with vaccine‐associated sarcoma given postsurgical curative (n = 46, most with clean margins) or coarse fractionated radiotherapy (n = 27, most with either macroscopic disease or dirty margins). The former animals displayed a median survival of 43 months and a median progression free interval (PFI) of 37 months, the latter reached a median survival of 24 months and a median PFI of 10 months. In cats undergoing coarse fractionated therapy, factors predictive of a better outcome included lack of visible mass (n = 10) as opposed to macroscopic disease (n = 17, survival: 30 versus 7 months, P = 0.025; PFI: 20 versus 4 months, P = 0.01), adjuvant chemotherapy for gross disease (n = 5/17, survival: 29 versus 5 months, P = 0.04) and a smaller number of surgeries preceding radiation therapy (coeff = 0.41, P = 0.03). The Ki67 index was not predictive for survival. We concluded that postsurgical curative and coarse fractionated radiotherapy are effective legitimate options for managing vaccine‐associated sarcomas.     

水泥砼路面滑模施工单质材料控制与管理

结合水泥砼路面滑模摊铺技术实际情况。阐述了各种单质材料管理的方法和控制要点。     

杂粮馒头的生产工艺研究及鉴定评价

实验室试验与实际生产应该紧密结合,经发酵蒸制而成的杂粮馒头,具备色多、光亮、皮软、光润、膨松喧软、筋力适度、淡香微甜等的感官性状,其有宜于配菜,久食不厌的特点。而且,杂粮馒头还有经济、实惠、物美、价廉、易消化等优点。     

森林粗木质物残体贮量及功能研究综述

粗木质物残体(CWD)在森林生态系统能量流动、物质循环以及维护森林生态系统的完整性和稳定性方面发挥着重要作用, 科学有效地对其贮量进行定量化研究, 对进一步了解CWD在生物地球化学循环过程中和全球碳循环与碳平衡中的地位与作用具有重要意义。文中论述了CWD的贮量、CWD的分解、CWD在碳贮量与碳循环中的重要作用以及影响CWD贮量和分解的原因, 系统阐明了CWD在促进森林生产力、维持生物多样性以及促成森林更新等方面的功能, 展望了CWD贮量定量化研究以及结构与功能研究的发展方向。     

复合菌剂发酵秸秆的作用及应用

以玉米秸秆为试验材料,研究了复合剂的添加量及发酵条件对对玉米秸秆纤维素和粗蛋白含量的影响.结果表明:在温度为25℃,菌种和秸秆比例为1:300的条件下,有氧发酵60、120、180、240、300和360 h后,秸秆纤维素含量分别下降了1.25%、5.09%、8.08%、8.51%、8.85%和9.31%,粗蛋白含量提...     

Note:Syringopais temperatella Lederer, 1855 and its parasitoids in wheat and barley fields in the southeast Anatolian region of Turkey

Larvae of the cereal leaf minerSyringopais temperatella Led. (Lep.: Scythridae) collected from wheat and barley fields in the southeast Anatolian region of Turkey during 2005–2006, and their parasitization rates, were determined in the laboratory,Bracon (Habrobracon) stabilis Wesmael andApanteles sp. (Hymenoptera: Braconidae) were identified as its parasitoids for the first time.