湖北太子山不同林分对降雨的截留作用研究     

李睦 《现代农业科技》2021,8(8)

本文在湖北太子山选取柏木纯林、马尾松纯林、麻栎五角枫混交林、柏木红果冬青混交林和马尾松红果冬青混交林共5种林分作为研究对象,采用天然降雨监测的方法,研究5种林分林分林冠层、灌草层和枯落物层分别对降雨的截留作用。结果表明林场中阔叶混交林的水源涵养能力最强,其次为针阔混交林,最差的是针叶纯林。  相似文献   

不同光强的LED白光与红蓝光对生菜生长及营养元素含量的影响     

周成波  刘文科  邵明杰  李宝石  王奇 《中国农业科技导报》2021,23(12):76-83

在人工光植物工厂中研究了不同光强的LED白光和红蓝光对营养液水培生菜生长、营养元素含量和累积量的影响。试验设置白光（WL）和红蓝光（RB）两个光质处理,光周期为16/8 h,分别设定三个光强：150（WL150、RB150）、200（WL200、RB200）和250（WL250、RB250）μmol·m^-2·s^-1,其中红蓝光光强比为4∶1,光暗周期16/8 h。结果表明,光强增加有促进生菜生长作用,随光强增加生菜地上部干、鲜重明显增加,WL200和WL250处理下生菜地上部干重比WL150分别提高了24.6%和49.7%。与红蓝光相比,白光显著提高生菜叶面积和地上部生物量。红蓝光提高了生菜叶片中大中量元素（N、P、Ca、Mg）和微量元素（Mn、Zn）的含量,白光则提高了K的含量,光质对C、Fe和Cu含量无明显影响。白光或红蓝光下不同光强对生菜叶片营养元素含量的影响并没有表现出明显的规律,只是红蓝光在200 μmol·m^-2·s^-1光强下多种营养元素（N、P、Ca、Mg、Mn、Cu和Zn）含量到达最大。在白光200 μmol·m^-2·s^-1的光强下,P、K、Ca、Mg、Fe、Mn、Cu和Zn的累积量最大,而在红蓝光250 μmol·m^-2·s^-1的光强下,10种营养元素的累积量均最大。相同光强下,红蓝光有利于生菜体内N、P、Ca、Mg、Mn和Zn含量的提高,而白光则更有利于C、N、P、K、Mg和Fe等的累积。因此白光处理更有利于促进生菜生长,并提高生菜体内N、C、P、K、Mg和Fe的累积量,其累积量的提高主要是由较高的生物量决定的。  相似文献   

Afforestation,restoration and regeneration——Not all trees are created equal     

Shaneka S. Lawson  Charles H. Michler 《林业研究》2014,25(1):3-20

Undulations in weather patterns have caused climate shifts of increased frequency and duration around the world. The need for additional research and model data on this pressing problem has resulted in a plethora of research groups examining a particular tree species or biome for negative effects of climate change. This review aims to （1） collect and merge recent research data on regeneration within old- and new-growth forests, （2） highlight and expand upon selected topics for additional discussion, and （3） report how shade tolerance, drought toler- ance, and inherent plasticity affect tree growth and development. Al- though shade and drought tolerance have been well studied by a number of research groups, this review reveals that in-depth analysis of a single or a few species in a given area will not generate the data required to implement a successful regeneration plan. Studies using historical accounts of previous species composition, information regarding site sea- sonality, species competition, and individual responses to drought and shade are needed to （1） develop best management plans and （2） ensure future modeling experiments are focused on a greater variety of species using more innovative methods to evaluate climate change effects.  相似文献   

A preliminary evaluation of throughfall sampling techniques in a mature coniferous forest     

Darryl. E. Carlyle-Moses  Chad. E. Lishman  Adam. J. McKee 《林业研究》2014,25(2):407-413

Rainfall, throughfall and stemflow were measured and canopy interception loss was derived for 14 rainfall events from June 22 to August 30, 2008 within a mature declining hybrid white spruce(Picea glauca(Moench) Voss × P. engelmannii Parry ex Engelm.)- subalpine fir(Abies lasiocarpa(Hook.) Nutt.)- lodgepole pine(Pinus contorta var.latifolia Dougl. ex Loud.) stand in south-central British Columbia, Canada. Stemflow was negligible during the study period, while, respectively throughfall and canopy interception loss accounted for approximately59.4% and 40.6% of the 50.1 mm of cumulative rainfall. Throughfall variability was assessed with three approaches involving roving and stationary wedge-type gauges, and stationary trough gauges. Throughfall exhibited large spatial variability with the coefficient of variability of study period throughfall sampled using 16 stationary trough gauges being30.3%, while it was 38.0% and 28.7% for 32 stationary and 32 roving wedge gauges, respectively. Our analysis suggests that a roving gauge method is better than a stationary approach since the errors associated with event mean throughfalls are summed quadratically and a greater portion of the canopy area is sampled. Trough gauges were more efficient than wedge gauges; however, this efficiency was less than expected given their much larger sampling areas, suggesting that spatial autocor-relation lengths of throughfall may be longer than the trough systems. The spatial distribution of throughfall showed a high degree of temporal persistence throughout the study suggesting the existence of stable "wet" and "dry" inputs to the floors of these coniferous forests.  相似文献   

氮磷钾肥施用对莴笋产量、收益及农学效率的影响     

王树志  徐明阳 《天津农业科学》2014,(8):35-37

通过田间小区试验,在天津市武清区研究了氮、磷、钾肥的施用对莴笋产量、经济效益及农学效率的影响。结果表明:氮、钾肥对莴笋产量影响较大,不施氮、钾肥莴笋减产7.4%和6.0%,与OPT处理产量相比,差异均达极显著水平;从经济效益来看,氮、钾肥施用对莴笋经济效益较好,增收分别为4 500元·hm-2和3 465元·hm-2;从养分农学效率来看,N的农学效率为13.5kg·kg-1,P2O5的农学效率为4.9 kg·kg-1,K2O的农学效率为15.5 kg·kg-1,莴笋养分农学效率依次为钾氮磷。  相似文献   

Green roof vegetation type affects germination and initial survival of colonizing woody species     

Lori E. Miller  Amy E. Heim  Jeremy Lundholm 《Urban Forestry & Urban Greening》2014,13(4):892-899

Green roofs provide a number of valuable ecosystem services compared to conventional roofs, but may require yearly maintenance. Trees and other woody plants that persist on the roof may damage or overload shallow-substrate green roofs and their removal is a standard maintenance procedure. The germination potential of colonizing species may differ depending on the vegetation surrounding them. The aim of this study was to determine whether the germination of colonizing tree species (Picea glauca and Ulmus glabra) will vary depending on which plant species form the established vegetation seeds land in. To determine germination success, survival, and seed capture ability of the plant canopy, tree seeds were added either directly to the growing medium or atop the plant canopy, in replicated monocultures of 14 species native to Nova Scotia. When seeds were added directly to the soil, no significant difference was detected between the monocultures for germination success or survival for U. glabra or P. glauca. However, when the seeds were added atop the plant canopy, percent germination of U. glabra was significantly higher in Carex argyrantha green roof modules. Overall, sod forming graminoids showed higher germination of U. glabra. The number of seeds reaching the soil was typically lower in vegetation with a denser canopy. This study demonstrates that some vegetation repels colonizing tree species by reducing ground contact. Although these effects differed according to tree species, non-vegetated substrates enhanced seedling persistence. Additionally, the majority of tree seeds that germinated failed to survive a single growing-season on shallow-substrate green roofs.  相似文献   

丹麦品氏托普基质对矮牵牛穴盘苗发芽和生长的影响     

陈曦  刘志洋 《黑龙江农业科学》2014,(6):82-84

为实现矮牵牛的大规模工厂化育苗,研究了不同基质对矮牵牛种子发芽和幼苗生长的影响。结果表明:与素土和普通草炭基质相比,丹麦品氏托普基质大大地缩短了矮牵牛生育期。丹麦品氏托普基质处理下的矮牵牛发芽率、发芽势和冠幅均高于其它两种基质处理,同时,植株感病率低,杂草生长减少。  相似文献   

内蒙古柠条生物量建模   总被引：1，自引：0，他引：1  

曾伟生  白锦贤  宋连城  邢利军  王雪军  赵学军  张振荣 《林业资源管理》2014,(6)

以内蒙古自治区的常见灌木种柠条(Caragana microphylla)为研究对象,基于大样本的生物量实测数据,利用非线性误差变量联立方程组方法,建立了单株水平的地上生物量模型及其相容的地下生物量模型和根茎比模型,并建立了基于平均植冠面积和密度或覆盖度的群落水平的总生物量模型。结果表明:植冠面积是影响单株生物量的首要因子,其次才是丛生枝个数;基于植冠面积和丛生枝个数的单株地上生物量模型,其确定系数能接近0.7,但地下生物量模型的确定系数要低些,还不到0.5;单株地上生物量和地下生物量模型的平均预估精度均能达到90%左右,总生物量的平均预估精度能达到92%以上,完全可用于内蒙古自治区范围内柠条灌木林的生物量估计。以单株总生物量模型为基础,直接推导出不同密度或覆盖度的群落总生物量模型,可为建立群落水平的灌木生物量模型提供借鉴。  相似文献   

黔西南州山洞烤烟小棚漂浮育苗研究     

韦业旺  刘森  王丰  蔡坤伦  邹龙明 《现代农业科技》2014,(24)

常规烤烟小棚育苗受天气影响大,在黔西南州育苗阶段早春低温和后期高温严重影响壮苗培育。黔西南州山洞资源丰富,利用其温度相对恒定的特点开展漂浮育苗,规避灾害天气。该研究选用黔西南烟区常规品种云烟85,开展常规育苗和山洞育苗对比试验。结果表明:山洞育苗能提高烤烟出芽率,缩短出苗时间,增加物质积累,提高烟苗均匀性,降低苗床病害发生率。  相似文献   

花生生理和农艺性状对冠层温度的影响     

任学敏  朱雅  王长发 《西北农林科技大学学报(自然科学版)》2014,42(10):81-86

【目的】探索花生生理和农艺性状对冠层温度的直接和间接影响,为分析不同基因型花生冠层温度差异机理提供参考。【方法】自花生结荚期到收获,应用红外测温仪对12个北方大花生品种的冠层温度进行了连续观测,并测定了花生主茎功能叶片(主茎顶3叶)的过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、硝酸还原酶(NR)活性及可溶性蛋白、丙二醛(MDA)、可溶性糖和叶绿素含量,收获时调查了分枝数、侧枝长和主茎高等农艺性状,对各生理和农艺性状与冠层温度的关系进行相关分析和通径分析。【结果】12个大花生品种的冠层温度有分异,其中,豫花153的冠层温度最低,开农41的最高。花生生理和农艺性状对冠层温度均有强烈影响。生理指标中影响最大的是叶绿素含量,其次是SOD活性、NR活性和可溶性蛋白含量,而CAT活性、MDA含量和可溶性糖含量的影响较小;农艺性状中以主茎高的影响最大,侧枝长和分枝数次之。【结论】花生冠层温度与生理和农艺性状密切相关,生理活性强,植株高、分枝数多,利于冠层温度降低。  相似文献