落叶松人工林地位指数级导向曲线模型的研究

本文用约1000块样地资抖,系统地研究了黑龙江省落叶松人工林的地位指数级导向曲线模型。通过林业统计分析软件Statistica6.0对各落叶松人工林数据进行拟合、分析比较,结果为：从拟合精度、曲线走向与散点分布趋势、残差分布等综合考虑,舒马切尔曲线函数比较适合落叶松人工林地位指数级导向曲线模型的拟合。     

杉木林杆材阶段能量积累和分配的研究

目前森林生态系统生产力的研究 ,多以干物质量作为指标 ,这对深入了解生态系统的功能 ,生态效益都有一定的局限性。必须把生物量与能量结合起来 ,因为生物量和能流的研究 ,是人工林生态系统结构和功能的研究中最主要的一环 ,是研究物质生产、物质循环和能量流动的基础。关于森林各组织器官的热值和能量的研究 ,国内外许多学者做过这方面的工作。刘世荣等 (1990 )研究了落叶松 (Larixgmelinii)林群落能量积累、分配、固定和转化的规律 ;陶金川等 (1990 )探讨了银鹊树 (Tapisciasinensis)群落的生物量和能量的现存量 ;张文其等 (1995 )对鹤山…     

吡虫啉与三种拟除虫菊酯杀虫剂对马铃薯桃蚜的联合毒力

本文探讨了吡虫啉分别与氰戊菊酯、高效氟氯氰菊酯和联苯菊酯复配对马铃薯桃蚜的防治效果,为合理有效地应用复配剂对其进行化学防治提供依据。应用共毒因子法和共毒系数法分别确定了最佳药剂配伍和最佳复配比例。采用共毒因子法测定结果表明,吡虫啉与氰戊菊酯混配对马铃薯桃蚜防治有明显增效作用。进一步采用共毒系数法测定表明,吡虫啉与氰戊菊酯复配比例为2∶3时,增效作用最显著,共毒系数达276.82;吡虫啉与氰戊菊酯以6∶1复配时,表现出拮抗作用。     

不同种植密度条件下单混种作物的生长曲线

代谢比例理论（Metabolic Scaling Theory）认为,植物小个体或幼苗的生物量和物质能量代谢速率之间的异速生长指数为1,而随着植物个体的逐渐增大,其代谢异速生长指数逐渐趋近于3/4。2012年,Deng等基于代谢比例理论建立了植物小个体的动态生长模型。然而,对于受到种内或种间不同竞争压力的植物个体来说,其生长过程无疑将受到邻体竞争的影响,他们是否仍然遵循上述植物小个体的动态生长模型尚不得而知。本研究针对此科学问题选取了春小麦（Triticum aestivum）、胡麻（Linum usitisimum）、玉米（Zea mays）3种作物分别进行两两组合混合种植以及单独种植,种植密度分别为高、中、低3种不同密度梯度;在作物出苗至成熟期间,分别对株高、基茎、冠幅、生物量、以及不同时期样方植物密度共进行6次跟踪测定。通过对Deng等建立的植物小个体动态生长模型的拟合分析,发现在种植密度梯度下不论单种还是混种,其植物个体的生长曲线均符合植物小个体动态生长模型,且具有相似生态位的物种混种条件下的个体生长状况要好于单种条件下的个体生长状况,而低密度条件下的生长状况亦显著优于中、高密度个体生长状况。总之,不同竞争压力下的植物个体,其生长速率和成熟大小虽有所变化,但其生长曲线均符合上述生长模型的预测。该研究不但对植物小个体生长模型和代谢理论的可靠性进行了进一步的验证,而且还使该理论的应用与发展得到进一步的完善。     

茶园生物菌肥的营养效应研究

研究腊状芽孢杆菌(Bacillus megaterium)、K1菌株(胶质芽孢杆菌)(Bacillus mucilaginosus)及K2(胶质芽孢杆菌)、K3(胶质芽孢杆菌),两类细菌在实验室条件下的解磷、解钾作用,通过对特定波长、不同pH值条件下培养液的吸光度来确定单位体积菌数的多少,结果显示,在pH值为5.5~6.5之间的吸光度较高,即这些菌株能在此pH值范围内较好生长。将菌株发酵液与菜籽饼混合,配制成生物菌肥施入茶园土壤具有提高土壤速效养分含量、促进茶树新梢生长、增加茶叶产量的效果。结果表明:所选菌株作为菌种配制茶园生物菌肥,对提高土壤肥力,促进茶树生长,增加茶叶产量均有较好效果。     

栓皮栎研究进展与未来展望

综述了国内外近30 a来关于栓皮栎生物生态学特性、地理分布、资源培育、综合利用等方面的研究进展,对当前工作中存在的问题进行了探讨,对未来栓皮栎的研究工作进行了展望,以改善生态环境、增加农民收入、促进地方经济发展为目的,结合生态效益、社会效益和经济效益,加强残败次生天然林更新、遗传改良、丰产林培育等工作,为栓皮栎保护恢复和永续利用提供参考。     

青钩栲人工林生态系统碳储量及其分配格局

对广西南宁良风江27年生青钩栲人工林生态系统的生物量尧碳密度尧碳储量及其空间分配特征进行了研究遥结果表明院青钩栲人工林不同器官的平均碳素密度为459.6~491.9 g/kg袁其含量由高到低依次为院枯枝>干>根兜>中根>粗根>大枝>细枝>细 根>叶袁青钩栲各器官的碳素密度存在显著差异曰青钩栲人工林生态系统中的碳储量表现为院土壤层>乔木层>灌木层>凋落物层>草本层曰土壤碳素密度随着深度的增加逐渐降低袁碳素含量主要集中在0~40 cm的土层曰青钩栲人工林生态系统的碳储量为206.96t/hm2袁其中乔木层占39.61%袁灌木层占2.53%袁草本层占0.14%袁凋落物层占0.54%袁土壤层占57.18%曰乔木层中树干的碳储量最高袁为43.24 t/hm2袁占总碳储量的20.89%曰青钩栲人工林每年的净生产力为21.51 t/hm2袁净固碳量为8.80 t/hm2袁净碳素积累量为3.05 t/hm2袁有较好的碳汇潜力遥     

间伐对杉木人工林生长的短期影响

为了研究杉木人工林在不同经营密度下的生长情况,以福建将乐国有林场杉木人工林为研究对象,设计间伐强度为50%、33%、25%、20%以及未间伐5个不同强度的间伐试验,分析在不同间伐强度下胸径生长、树高生长以及蓄积量的变化。结果表明:适度的间伐能够伐除小径阶的林木,直径分布曲线左偏型减弱。间伐强度为20%、25%、33%、50%的林分年平均胸径生长量分别是0.99、1.05、1.25、1.30 cm,比未间伐的生长量0.83 cm都高,且各个间伐强度下林木胸径生长由大到小依次为优势木、中庸木、劣势木;间伐强度为20%、25%、33%、50%强度间伐的林分树高生长量分别是0.94、0.91、0.89、1.01 m,未间伐的生长量为0.92 m,差异均不显著。林分蓄积结构的分析发现,间伐后1 a,林分的蓄积生长率随着间伐强度的增加而增加。     

中华绒螯蟹养殖群体与野生群体的种群遗传学研究

研究旨在探究安徽中华绒螯蟹种质资源状况以及资源混杂程度,以期为中华绒螯蟹资源的科学保护、合理利用以及相关产业政策的制定提供理论依据。采集了中华绒螯蟹4个养殖群体和长江野生群体共170尾样本,基于线粒体分子标记,进行种群遗传学分析。结果表明,长江野生中华绒螯蟹遗传多样性低,盲目捕捞可能造成野生资源衰退。野生群体与养殖群体间未出现显著遗传分化,存在严重的种质混杂。研究探明了长江中华绒螯蟹的资源现状,为其科学的保护提供理论依据。     

Effects of Jiedu-Qingfei mixture on NF-κB and p38 MAPK pathways in lung tissues of rats with Mycoplasma pneumoniae infection

AIM: To observe the therapeutic effect of Jiedu-Qingfei mixture on Mycoplasma pneumoniae (MP)-infected rat lung tissues and to explore its mechanism. METHODS: SD rats (n=40) were randomly divided into 4 groups:blank control group, model group, Jiedu-Qingfei group and positive control group, with 10 rats in each group. The rats in experimental groups were slowly dripped with 1×10⁹ CFU/L MP solution into their nostrils for 4 d. One rat in each group was sacrificed for MP nucleic acid detection at the second day after inoculation, and the other rats were given gavage therapy. The rats in blank control group and model group were intragastrically given the same volume of normal saline, the rats in Jiedu-Qingfei group were given 8 mL/kg Jiedu-Qingfei mixture daily for 4 weeks, and the rats in psoitive control group were given dexmethasone sodium phosphate (0.5 mg·kg^-1·d^-1). After the experiment, the rats were killed. The serum and bronchoalveolar lavage fluid (BALF) were collected for detecting the levels of interleukin-12 (IL-12), IL-13 and TNF-α by ELISA. The right lung tissues were used for pathological observation and HE staining, while the left lung tissues were used to detect the expression of NF-κB p50, I-κBα and p38 mitogen-activated protein kinase (p38 MAPK) at mRNA and protein levels. RESULTS: The results of MP nucleic acid detection showed that all the rats except blank control group were MP nucleic acid positive, indicating that the rat model of MP infection was successfully established. On the 1st day of the treatment, the pathological scores of the lung tissues in model group and Jiedu-Qingfei group were significantly higher than those in blank control group (P<0.05). After treatment, the pathological scores of the lung tissues in mo-del group were significantly higher than those in blank control group and Jiedu-Qingfei group. The levels of IL-12 in the serum and BALF in model group were significantly lower than those in blank control group after MP infection (P<0.05), while those after treatment with Jiedu-Qingfei mixture were significantly higher than those in model group (P<0.05). The levels of IL-13 and TNF-α in the serum and BALF of MP-infected rats were increased significantly, while those after treatment with Jiedu-Qingfei mixture were significantly lower than those in model group (P<0.05). The mRNA expression levels of NF-κB p50 and p38 MAPK in model group were increased significantly (P<0.01). After treatment, the mRNA expression levels of NF-κB p50 and p38 MAPK were decreased significantly compared with model group (P<0.01). The mRNA expression level of I-κBα in model group was significantly lower than that in control group. After treatment, the mRNA expression of I-κBα in Jiedu-Qingfei group was significantly higher than that in model group (P<0.05). The protein levels of NF-κB p50 and p38 MAPK in the lung tissues of model group were significantly higher than those of blank control group. After treatment, the protein expression of NF-κB p50 and p38 MAPK was decreased significantly. The protein level of I-κBα in model group was significantly lower than that in blank control group, and after treatment with Jiedu-Qingfei mixture, the protein expression level of I-κBα was increased significantly (P<0.05). CONCLUSION: Jiedu-Qingfei mixture may attenuate lung tissue inflammation caused by MP through NF-κB and p38 MAPK pathways.