A comparison of decomposition dynamics among green tree leaves,partially decomposed tree leaf litter and their mixture in a warm temperate forest ecosystem     

Juan Wang  Yeming You  Zuoxin Tang  Xiaolu Sun  Osbert Jianxin Sun 《林业研究》2016,27(5):1037-1045

Decomposition dynamics were compared among green tree leaves, partially decomposed tree leaf litter (i.e., decayed tree leaf litter on forest floor) and a mixture of the two in a warm temperate forest ecosystem in central China to test the influence of litter chemical quality on the degree of decomposition. The study was conducted in situ at two contrasting forest sites, an oak forest dominated by Quercus aliena var. acuteserrata Maxim., and a mixed pine and oak forest dominated by Pinus armandii Franch. and Q. aliena var. acuteserrata. We found marked differences in the rate of decomposition among litter types at both forest sites; the litter decomposition constant, k, was about 39 % greater at the oak forest site and more than 70 % greater at the pine-oak forest site, for green leaves than for partially decomposed leaf litter. The decomposition dynamics and temporal changes in litter chemistry of the three litter types also greatly differed between the two forest sites. At both forest sites, the higher rate of decomposition for the green leaves was associated with a higher nitrogen (N) content and lower carbon to N ratio (C/N) and acid-unhydrolyzable residue to N ratio (AUR/N). We did not find any non-additive effects when mixing green leaves and partially decomposed leaf litter. Our findings support the contention that litter chemical quality is one of the most important determinants of litter decomposition in forest ecosystems at the local or regional scale, but the effect of litter chemical quality on decomposition differs between the contrasting forest types and may vary with the stage of decomposition.  相似文献   

杉木初级种子园遗传效应的一个验证          下载免费PDF全文

陈益泰  张建章  游昌顺  蓝玉 《林业科学研究》1990,3(2):151-154

从杉木林中采集七株优树的种子，并在种子园内采集相同优树无性系自由授粉种子，进行成对对造林比较试验，造林四年后，来自种子园的后代其生长量显著高于来自林分的后代，树高增长9．1％，胸径增加14．5，由此，对杉木初级种子园的遗传效应加以肯定并进行评论。  相似文献   

龙南遗址红烧土植物蛋白石分析     

郑云飞  游修龄 《中国水稻科学》1994,8(1):55-56

龙南遗址红烧土植物蛋白石分析郑云飞，游修龄，徐建民，边其均（浙江农业大学，杭州３１００２９）ＰｌａｎｔＯｐａｌＡｎａｌｙｓｉｓｏｆＬｏｎｇｎａｎＮｅｏｌｉｔｈｉｃＳｉｔｅ￥ＺＨＡＮＧＹｕｎｆｅｉ；ＹｏｕＹｉｕｌｉｎｇ；ＸｕＪｉａｎｍｉｎ；ＢＩＡＮＱｉ...  相似文献   

Ectomycorrhizal symbioses increase soil calcium availability and water use efficiency of Quercus acutissima seedlings under drought stress     

Li  Yanan  Zhang  Tengzi  Zhou  Yongbin  Zou  Xiaoming  Yin  You  Li  Hui  Liu  Liying  Zhang  Songzhu 《European Journal of Forest Research》2021,140(5):1039-1048

European Journal of Forest Research - Ectomycorrhizal fungi (EMF) can enhance drought resistance of host plants by increasing nutrient and water absorption. Calcium (Ca) plays a central role in...  相似文献   

木奶果种质资源的遗传多样性分析及DNA指纹图谱构建          下载免费PDF全文

周彩霞  罗培四  孔方南  蒋娟娟  卓福昌  李文砚  周婧  韦优 《南方农业学报》2022,53(5):1207-1215

【目的】对来自广西、云南、海南和广东的63份木奶果种质资源进行遗传多样性分析,并构建对应的DNA指纹图谱,为木奶果种质资源的分类鉴定、保护和利用提供理论参考。【方法】选取3份地理位置相差较远的种质,从75条SCoT引物中筛选出条带清晰、重复性好和多态性丰富的引物,对63份供试种质进行多态性扩增,利用Popgene 1....  相似文献   

Investigation of the Role of Androstenedione-19-oic Acid in the Presence of 19-Norandrostenedione in Intact Male Horse Plasma Using Liquid Chromatography–Tandem Mass Spectrometry     

Youwen You  Cornelius E. Uboh  Lawrence R. Soma  Fuyu Guan  Daniel Taylor  Xiaoqing Li  Ying Liu  Deborah Tsang 《Journal of Equine Veterinary Science》2014

A liquid chromatography–tandem mass spectrometry method was developed to confirm the presence of androstenedione-19-oic acid in intact male equine plasma and to show the source of 19-norandrostenedione in equine plasma. Androstenedione-19-oic acid was recovered from acidified plasma by liquid–liquid extraction using methyl tert-butyl ether and separated on an Ace 5 C₈ column. A triple quadrupole mass spectrometer was used to detect the analytes in negative electrospray ionization mode. Limits of detection, quantification, and confirmation of the method were 0.1, 0.5, and 1.0 ng/mL, respectively. The linear dynamic range of quantification was 0.5–50 ng/mL. The presence of androstenedione-19-oic acid was confirmed in all plasma samples obtained from intact male horses but not those from gelded and female horses; the average concentration was 3.1 ± 1.6 ng/mL, suggesting androstenedione-19-oic acid is an endogenous compound only in intact male horse plasma samples. The conversion of androstenedione-19-oic acid to 19-norandrostenedione in equine plasma was demonstrated by spiking androstenedione-19-oic acid into blank plasma and monitoring the generation of 19-norandrostenedione and its increase in concentration during storage. Results indicated that androstenedione-19-oic acid was readily converted into 19-norandrostenedione; the higher the storage temperature, the faster the conversion. The conversion was not affected by the types of plasma samples collected from gelded and female horses or by anticoagulants used in blood collection to harvest plasma. Compared with other matrices such as water, methanol, and phosphate-buffered saline, the conversion of androstenedione-19-oic to 19-norandrostenedione in equine plasma was faster, suggesting that there is an unknown factor(s) in equine plasma that enhances the conversion.  相似文献   

乙醛、对苯二甲酸、乙二醇对鲢、草鱼的联合毒性   总被引：12，自引：0，他引：12       下载免费PDF全文

陈碧鹃  袁有宪  王会平 《中国水产科学》2001,8(1):73-76

实验按毒性单位1：1：1设计，研究乙醛、对苯二甲酸、乙二醇等化纤污水中主要污染物对鲢、草鱼的稚鱼和幼鱼的联合毒性。实验结果表明，乙醛＋对醛二甲酸＋乙二醇对鲢的稚鱼和幼鱼的96hLC50值分别为21300．6和27438.8mg/L；对草鱼的稚鱼和幼鱼的96gLC50值分别为27387．3和25606．2mg/L。联合毒性效应均表现为相加作用。  相似文献   

实时定量PCR技术及其在水生动物研究中的应用     

周优  岳志芹  孙敏  梁成珠  刘荭  邓明俊  汪东风 《中国水产科学》2007,14(Z1)

多聚酶链反应(PCR)研究与应用的飞速发展使其成为分子生物学实验室重要的工具,实时定量PCR(Real-time quantitative PCR)技术是20世纪90年代中期发展起来的一种新型核酸定量技术,该技术以其特异性强、灵敏度高、速度快、污染少等优点,促进了PCR技术的发展.实时定量PCR技术在水生动物研究中有着广泛的应用,目前主要集中在病原体检测、定量分析以及基因表达差异等方面.本文对实时定量PCR技术的原理、特点及5种主要的荧光化学作一介绍,对其目前在水生动物研究中的应用进行了概述,并探讨了该技术存在的问题和应用前景.  相似文献   

钻井噪声与振动对鲤鱼生长的影响     

孙耀  宋云利  赵俊  陈聚法  袁有宪  姜尚亮  张德华 《海洋水产研究》2001,22(1):62-68

采用剪标记法，现场模拟测定了钻井噪声与振动对鲤鱼生长的影响，研究结果表明，钻井噪声与振动对鲁鱼生长有显著影响，其临界等效噪声级和振动级约为８３．９dB和８９.7dB,影响域径约为９m，污染持续时间，体重和群居行为等生态因素，能显著改变钻井噪声与振动对鲤鱼生长的污染效应，由在污染消失后鲤鱼生长率能迅速恢复，这说明钻井噪声与振动鲤鱼的生长的污染效应，由于在污染消失后鲤鱼生长率能迅速恢复，这说明钻井噪声与振动对鲤鱼的影响机制可能是合理的。  相似文献   

珠江卷口鱼年龄生长、食性和繁殖的研究   总被引：5，自引：2，他引：5  

廖国璋  尤炳赞  白岳强  高登峰  刘少明  梁森汉  庞世勋 《水产学报》1986,10(1):70-86

本文报道了珠江卷口鱼的年龄生长、食住和繁殖方面的研究结果。通过分析确定:卷口鱼的年龄级由I—IV龄鱼组成,各龄鱼分别占渔获物总量的42.21％、38.21％、19.21％和0.38％。用统计学方法,计算出卷口鱼体长与鳞长的相关式为:L=8 43.30R(r=0.9956);体长与体重的相关式为:W=8.226×10~(-3)L~(3.374)(Γ=0.9654)。对卷口鱼各种食物的组成、季节变化及出现率作了分析探讨。卷口鱼个体绝对怀卵量波动于7878—48880粒之间,平均22250.7粒。绝对怀卵量与体长和体重的相关式为:R=4.5419L~(3.6208)和R=40.88W 1209. 文中对卷口鱼的资源繁殖保护,网具使用和合理捕捞规格等问题进行了讨论。  相似文献