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1.
A 70-year-old thinned northeastern Fagus-Betula-Acer stand in the Adirondack Mountains of northern New York was fertilized with varying combinations of N, P, K, and lime in the spring of 1976.Betula alleghaniensis Brit.,Acer saccharum Marsh.,Acer rubrum L., andFagus grandifolia Ehrh. foliage was collected in the autumn for 1974 through 1977 and analyzed for foliage areas and weights, and levels of ash, N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, Cu, and Co. Comparisons are made within species and among treatments, expressed as concentrations on a dry weight basis. Elemental composition is examined to determine the differential foliar responses to fertilization.Contribution of State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210.The authors are Graduate Research Assistant, Director of Huntington Forest, Technical Research Assistant, and Professor of Forest Soil Science (now deceased), SUNY, respectively.  相似文献   

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Summary Using deviations of the cumulative height growth due to fertilization treatments from the linear finite difference curve of untreated red pine trees in plantations, it was noted that: 1) large-sized trees responded in height growth to fertilization in the year following treatment while the medium and small trees took two years to respond; 2) medium-size trees responded to fertilization similar to large trees, but to a lesser magnitude; and 3) small trees are further suppressed by fertilization due to growth responses in the large medium trees.Contribution of the Silviculture Department, State University College of Forestry at Syracuse University, Syracuse, New York 13210.The authors are, respectively, Professor of Silviculture, Tokyo University of Agriculture and Technology and Visiting Professor of Silviculture, State University College of Forestry at Syracuse University, 1966–67; Forester, Continental Can Co., Augusta Division, Georgia; Professor of Silviculture, State University College of Forestry at Syracuse University.  相似文献   

3.
Summary The P, K, Ca, and Mg contents of throughfall and stemflow from K-fertilized and/or irrigated plots from adjacent sites differing in productivity in 39-year-oldPinus resinosa plantations were determined. The amounts of these elements leached from the tree canopies (throughfall plus stemflow) during April through October varied significantly according to site and treatment. These amounts ranged in kg per ha from −0.03 to 0.23 for P, 2.05 to 8.78 for K, 1.55 to 3.63 for Ca, and 0.02 to 0.44 for Mg. Leaching of P, K, and Ca from the trees was usually greater on the more productive site than on the poorer one. In general, the fertilization treatment was correlated with increasing amounts of P, K, and Ca leached, whereas the irrigation treatment was correlated with decreasing amounts of P, K, and Ca leached. For Mg, leaching was consistently greater on the poorer site than on the more productive one; further, it was greatest on the control plots and least on plots both fertilized and irrigated. Gross precipitation of 61.26 cm contained P, K, Ca, and Mg in amounts of 0.33, 0.84, 2.96, and 0.83 kg per ha, respectively. Volumes of both throughfall and stemflow were significantly affected by site conditions. Although throughfall was not affected by treatment, stemflow varied significantly according to plot treatment and was also highly and positively correlated with tree diameter. Stemflow accounted for about 2 per cent of the total water volume collected beneath the canopies, and contained, on a relative basis, considerably less P, an equivalent amount of K, twice as much Mg, and four times as much Ca as throughfall. Contribution of the Northeastern Forest Experiment Station, Forest Service, USDA, and Department of Silviculture and Forest Influences, State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210.  相似文献   

4.
Summary The vertical distribution of inorganic nutrient concentrations in red pine were dependent on the foliage age. Older foliage did not show an average vertical gradient while younger foliage did show a significant gradient. Horizontal gradients across foliage age classes in a branch whorl were consistent for all branch whorls, but the relative difference between the concentration of the current foliage and foliage three years-old or older was dependent on crown position. Coefficients of variation (CV) did not show a variability gradient in the crown for nitrogen and phosphorus. Variability of potassium tended to decrease as foliage age increased. Contribution of the University of Florida, Soil Science Department, Gainesville, FL and State University of New York, College of Environmental Science and Forestry, Syracuse, New York. Florida Agricultural Experiment Station Journal Series No. 3017.  相似文献   

5.
Referee: Dr. Charles A. S. Hall, Department of Environmental Studies, State University of New York, College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210 Biofuel production systems are sometimes claimed to be able to fill in for future fossil fuel shortages as well as to decrease carbon dioxide emissions and global warming. As such, they are often promoted as a “green” alternative to fossil fuels. I present a comprehensive, system-based case study of biofuel production from maize or corn (Zea mays L.) and evaluate it critically in this review. The case study is taken as an example of the comprehensive approach that I suggest for any energy crop. I conclude that the biofuel option on a large scale is not a viable alternative based on economic, energy and eMergy (amount of available energy [exergy] of one form [usually solar] that is directly or indirectly required to provide a given flow or storage of exergy or matter) analyses of the case study data and estimated possible improvement of yield and efficiency. This is true for developed countries due to their huge energy demand compared with what biofuel options are able to supply as well as for developing countries due to the low yield of their agriculture and competition for land and water for food production. However, biofuels may contribute to optimizing the energy and resource balance of agricultural, livestock, or industrial production systems at an appropriate scale. I present a proposal to integrate ethanol production with industrial activities within a “zero emission framework” as a suggestion for optimization strategies capable of making the biofuel option more sustainable and profitable in those cases where it is appropriate.  相似文献   

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Bacterial associations of coniferous mycorrhizae   总被引:2,自引:0,他引:2  
Summary A study was made of the bacterial flora associated with mycorrhizae and non-mycorrhizal roots ofPicea engelmanni, P. pungens, Pinus aristata, P. flexilis, andPseudotsuga menziesii seedlings up to 3 dm in height.A total of 369 bacterial isolations were made, of which 116 cultures were lost, mainly as a result of dying out. Fifty-one species were recognized from the surviving cultures. Of these, 22 were associated with only mycorrhizae and seven with only non-mycorrhizal roots. Most species grew best on media containing glucose.Picea engelmanni andPinus aristata were hosts to the greatest variety of bacterial species.Research conducted in partial fulfillment of the requirements for the M. A. degree Western State College, Gunnison, Colorado, 1963.  相似文献   

9.
The New York Botanical Garden initiated its Graduate Studies Program through a cooperative agreement with Columbia University in 1896. This arrangement continued until the late 1960s, when the Biology Department at Columbia chose to emphasize laboratory-related research and discontinued its organismal programs. At the time a new partnership was formed with what was to become Lehman College of the City University of New York—a program that has continued through the present. Since the inception of its Graduate Studies Program 100 years ago, the Garden has provided sponsorship, guidance, and resources to help more than 200 studients receive graduate degrees. In recent years the Garden has expanded its graduate program to include four additional university affiliates: the Department of Biology at New York University, the Institute of Systematic Botany at Cornell University, the School of Forestry and Environmental Studies at Yale University, and, in a new agreement with an old partner, the Center for Environmental Research and Conservation at Columbia University.  相似文献   

10.
全球气候变化对小兴安岭阔叶红松林影响的动态模拟研究   总被引:19,自引:0,他引:19  
应用林窗模型(Forest Gap Model)及4种大气环流模式(General Girculation Models,GCMs)CO2加倍“平衡响应”数值试验结果模拟了小兴安岭阔叶红松林对未来气候变化的动态响应过程。结果表明,在美国高达空间研究实验室(Goddard Institute for Space Studies,简记GISS)和美国俄勒冈州大学(Oregon State Univer  相似文献   

11.
We consider an ecological model by Levin and Segel (1976) for predator-prey planktonic species, which consists of two reaction-diffusion equations, and extend it to plankton populations with time-varying diffusivities. The local stability of uniform equilibria is examined both analytically and numerically. It is found that diffusive instability is less likely to occur in systems with time-varying diffusivity than those with constant diffusivity. Contribution No. 803 of the Marine Sciences Research Center, State University of New York, Stony Brook Supported by the Danish Science Research Council (Grant nos. 11-7128, 11-8321), the Danish Research Academy (Grant nos. E-880011, V-890085) and a Travel Grant for Mathematicians (Rejselegat for Matematikere) Supported by Hudson River Foundation, Grant no. 01488AO37  相似文献   

12.
杨梅园实行精耕细作,会造成生物多样性下降、水土流失加重、杨梅病虫害加剧等不良后果。为克服或缓解这些难题,对杨梅林开展了不同类型的混交栽培模式和抚育方式的研究。结果表明:进行机械割草的杨梅园生物多样性较优,其维管束植物总计达78种,而以药剂除草的,总计仅11种,差异极显著;"杨梅针、阔、竹混交林+自然生草+机械割草"、"杨梅纯林+自然生草+机械割草"和"杨梅纯林+清耕(除草剂除草)"等三种栽培与抚育类型的主要病害有杨梅癌肿病等2种,主要虫害有白蚁类、袋蛾类、栗黄枯叶蛾等7种(类),均以针、阔、竹混交栽培模式受害最轻。对"杨梅+蓝莓"、"杨梅+蕨类(种植)"和杨梅自然生草等3种栽培模式以及机械割草、人工割草和药剂除草等3种抚育方式的"三大效益"进行了综合评价。  相似文献   

13.
一株小麦赤霉病拮抗菌的筛选鉴定及防治效果分析   总被引:1,自引:0,他引:1  
自小麦赤霉病发病田块土壤中,分离得到1株小麦赤霉病高效拮抗菌株。通过形态特征、生理生化特性和16S rDNA序列比对分析,将这株拮抗菌株鉴定为奇异变形杆菌(proteus mirabilis)。P. mirabilis DY05发酵液和无细胞上清均可显著抑制禾谷镰刀菌菌丝体生长(抑制率分别为79.50%和51.25%)和分生孢子萌发(抑制率均为100%),减少呕吐毒素产生(分别减少84.32%和82.82%)。田间赤霉病防治试验结果显示,接种DY05,可降低发病率52.13%,同时病情指数降低48.74%,显示出较好的防治效果。促生生理活性评价试验结果显示,菌株DY05可以产生铁载体和IAA,并具有溶磷作用和ACC脱氨酶活性,具有很好的促生长潜力。盆栽试验结果表明,菌株DY05对小麦植株生长具有显著的促进作用。与对照组相比,菌株DY05处理可以显著增加小麦幼苗茎高、根长、鲜重和干重,其中茎高、根长、鲜重和干重分别提高了22.21%、26.41%、44.77%和26.53%。分离得到的拮抗菌株DY05具有拮抗病原真菌和促进植物生长的双重功能,为开发禾谷镰刀菌生物防治制剂提供了菌种材料。  相似文献   

14.
沙尘暴对北京市空气细菌多样性特征的影响   总被引:1,自引:0,他引:1  
亚洲沙尘暴携带着各类污染物质,严重影响下风向地区大气过程及生态系统和相关人群的健康。然而,沙尘天气对中国华北地区空气细菌群落及多样性特征影响的研究较少。以北京市为例,系统研究了沙尘暴对城市空气细菌多样性特征的影响。2015年4月,通过定点采样连续收集了一次沙尘暴及其前后4天的空气颗粒物样本,DNA提取、PCR扩增后进行16S rRNA基因高通量测序。共获得169122条高质量序列,生物信息学分析表明,北京市空气细菌物种多样性较高,沙尘暴不能引起细菌OTU数目的增加,但沙尘暴天气下细菌群落Pielou、Shannon和Simpson指数显著增加。菌群分类分析发现,北京市空气细菌由35个细菌门构成,其中变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)相对丰度最高,分别占总序列的32.76%、28.09%、25.46%和6.32%;芽单胞菌门(Gemmatimonadetes)和酸杆菌门(Acidobacteria)次之,分别占序列总数的2.11%和1.81%,其他细菌门的相对丰度均低于1%。沙尘暴天气下,变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、芽单胞菌门(Gemmatimonadetes)和酸杆菌门(Acidobacteria)显著升高(P<0.05),分别由31.67%、5.74%、1.82%、1.51%升高至41.46%、10.98%、4.48%和4.26%;而放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)显著降低(P <0.05),分别由28.84%、27.10%降低至22.13%和12.35%。冷杆菌属(Psychrobacter),纤维单胞菌属(Cellulomonas),不动杆菌属(Acinetobacter),假单胞菌属(Pseudomonas)和梭菌属(Clostridium)可能含有人类条件病原菌,其在沙尘暴天气中相对丰度下降,但绝对丰度会大幅增加。沙尘暴能降低人体免疫力,因此致病菌潜在健康风险可能显著增强。通过聚类分析和主成分分析发现,沙尘暴日与非沙尘暴日空气细菌群落差异较大,而沙尘暴前后群落结构差异较小。沙尘暴前后空气细菌群落α-多样性和β多样性均无显著差异,推测沙尘暴只能暂时影响空气细菌群落特征,不能显著改变其群落结构。本研究通过分析了沙尘暴侵袭下北京市空气细菌群落多样性特征及动态,为制定中国北方城市沙尘暴灾害预警措施和建立气传疾病的防控机制提供数据支持。  相似文献   

15.
Summary Plant species co-inhabiting a given geographical region often have distinetly different times of flowering. It is shown that such phenological spread, duc to short-term stochastic variation in weather variables, relaxes competition for empty sites to be colonized by diaspores. For sufficiently large spreads stable coexistence becomes possible. The applicability of the proposed hypothesis to the observed instances of phenological spread is discussed and shown to extend beyond that of other current theories.We thank L.-E. Liljelund, C. Solbreck and C. Wiklund for helpful comments. This work was carried out within the Swedish Coniferous Forest Project, supported by the Swedish Natural Science Research Council, the Swedish Environmental Protection Board, the Swedish Council of Forestry and Agricultural Research, and the Wallenberg foundation.  相似文献   

16.
The Role of State Departments of Education in Complex School Reform. Susan Lusi. New York: Teachers College Press, 1997. 217 pp.  相似文献   

17.
盛茂领  裴海潮 《昆虫学报》2002,45(Z1):96-98
 报道了采自河南的角姬蜂属Cosmoconus Foerster 二新种:西峡角姬蜂 C. xixiaens is Sheng, sp.nov. 和斑角姬蜂C. maculiventris Sheng, sp.nov.,并指出了与近 似种的主要区别特征。  相似文献   

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报道了采自河南的角姬蜂属Cosmoconus Foerster 二新种:西峡角姬蜂 C. xixiaensis Sheng, sp.nov. 和斑角姬蜂C. maculiventris Sheng, sp. nov.,并指出了与近似种的主要区别特征。  相似文献   

20.
报道采自河南省的锤举腹蜂属3新种:白跗锤举腹蜂Pristaulacus albitarsatus sp.nov.,黑足锤举腹蜂Pristaulacus memnonius sp nov.,脊锤举腹蜂Pristaulacus porcatus sp.nov.和1已知种:喀锤举腹蜂Pristaulacus karinulus Smith,2001。标本保存在国家林业局森林病虫害防治总站标本馆。  相似文献   

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