毛竹成竹期根际土壤微量元素变化规律

对黄山公益林场毛竹成竹期幼竹生长的根际土壤微量元素、pH值和有机质含量动态进行了测定,结果表明,幼竹根际土壤pH值介于4.86和6.04之间,属于适合幼竹生长的pH值范围。随幼竹生长,pH值呈开口向下的抛物线形状,8月中旬达到最高值,为6.03;有机质含量和Cu含量分别在7月初和6月中旬达到高峰,分别为38.77和 0.63,有机质含量在7月底达到最低点,而后慢慢升高,Cu含量则呈开口向下的W形状;Zn、Fe、Mn含量均在6月上旬达到高峰,而后均呈下降趋势。方差分析表明,10月幼竹根际土壤与非根际土壤Cu、Zn、Fe、Mn含量均存在显著差异,说明根际土壤对微量元素的溶解吸收相比非根际土壤来说,受根际小环境影响更显著。     

桤木人工林细根与土壤养分含量季节动态变化

对桤木人工林细根、土壤养分含量的季节变化及其两者之间的关系进行了研究.结果表明:(1)桤木细根中大量元素N、Ca、K、Mg、P含量冬季高,春季最低;微量元素Fe、Mn、Zn、Cu、Pb、Ni、Cd含量冬季最低,春夏季较高.(2)土壤各层中大量元素N、Ca、K、Mg、P含量冬季最低,夏季最高;微量元素Mn、Zn含量在冬季最低,秋季最高;Fe、Ni、Pb、Cu、Cd含量在冬季最高,春秋较低.(3)细根和土壤中大量元素含量在冬季存在负相关关系,微量元素Fe、Ni、Cd含量在一年四季均存在显著负相关关系,Mn、Cu含量在春季、夏季和秋季存在负相关关系,Zn、Pb含量在春季、夏季和秋季存在正相关关系.     

不同氮源作用下红松苗木根际pH的变化及其对根际磷的影响(英文)

用Kuchenbuch与Jungk所描述的根垫法,研究了两年生红松苗木根际变化过程。土壤样品长白山20mm土壤层,用不同形式的氮肥(NO3--N,NH4+-N和NH4NO3)进行处理,结果表明: 对照处理时近根pH值与有效P均低于土体;与对照相比,NH4+-N处理显著降低近根处pH值并促进了P吸收,产生更为明显的有效磷亏缺区;与NH4+-N处理相反,NO3--N处理使根际pH值相对于土体增加,延缓了P的吸收,近根处有效P含量与土体基本持平。NH4NO3处理时,根际pH值仅比对照略低,其对磷吸收的影响与对照处理相似。     

四川巨桉人工林微量元素养分诊断

采用相关分析和矢量诊断法对四川60块巨桉人工林标准地进行微量元素养分诊断。结果表明:1)5种微量元素中,Cu,Zn吸收量与林分蓄积显著相关;2)N,P,K等大中量养分吸收受多种微量元素供应量和吸收量的影响,微量元素与大量元素之间以及微量元素之间存在显著的交互作用关系,如Cu-K,Cu-Fe,Mn-N的促进作用,N-Zn,P-Zn,Ca-Zn,P-Fe,K-Fe,Mn-K以及Cu,Zn,Fe,Mn之间的相互拮抗作用;3)Cu在低海拔地区以过量毒害为主,高海拔地区以缺乏为主;Zn以稀释效应为主,极少数标准地缺乏受限;Fe含量地区变异较大,在土壤高pH值地区容易缺乏受限,土壤低pH值地区则容易过量毒害或发生拮抗作用;Mn含量普遍较高,多表现为拮抗和过量毒害作用,局部地区出现缺乏;B供应充分,主要为拮抗作用,表现稳定。     

不同林龄灰木莲人工林土壤微量养分特征

以广西高峰林场的10、12、18和51 a灰木莲人工林为研究对象,对比分析土壤中微量元素Fe、Mn、Cu、Zn、B、Al在不同林龄林分中的含量差异及其与土壤有机质、pH值及物理性质之间的相关性,为评价灰木莲人工林的土壤改良效果及养分管理提供依据。结果显示：(1)林龄变化对土壤微量元素含量特征存在显著影响(P<0.05),其中土壤微量元素Fe、Mn、Cu、Zn含量均随着林分年龄的增加而显著增加,有效B含量无显著变化,交换性Al含量显著降低。(2)各微量元素有效性指数从大到小依次为Fe、Cu、Mn、Zn、B、Al,除Al(0.57)外,其余元素的有效性指数均大于1,且随林龄增加而增大。不同林龄间微量元素有效性综合指数从大到小依次为51、18、10、12 a,整体呈现出随林龄增加而增大的趋势。(3)土壤有效态微量元素与土壤有机质、容重、持水量及总孔隙度之间相关性显著,其中有机质对土壤有效态微量元素含量变异的解释度最高(55.7%)。研究结果表明：灰木莲人工林土壤微量元素含量受林龄变化的影响,并且土壤有机质是引起不同林龄人工林土壤微量元素含量变化的关键因子;灰木莲的长期经营提高了土壤微量...     

中亚热带地区几个树种树干茎流的养分特征研究

对湖南株洲22～25年生的樟树、火炬松、槲栎、醉香含笑4个树种树干茎流及林外大气降水中N、P、SiO2、K、Ca、Mg、Cu、Zn、和Mn 9种养分元素含量进行了为期一年的测定.结果表明:不同月份大气降水养分元素含量不同,各元素各月平均含量按大小排序为Ca＞NH4-N＞SiO2＞Zn＞K＞NO3-N＞Mg＞Fe＞Mn＞P＞Cu;大气降水经过林冠层后,树干茎流中各养分元素含量变化基本一致,均表现季节动态变化,相对于大气降水,大多数元素含量增加;不同树种间树干茎流养分特征表现不同,按总含量值排序依次为火炬松、槲栎、樟树、醉香含笑;不同养分元素之间的相对含量也表现出较大的差别,NH4-N、Ca、K、SiO2含量最高,Mg、NO3-N、Zn、Mn含量居中,P、Fe、Cu含量最低.与大气降水相比,4个树种茎流共同表现为,Cu的含量变化较小,其它元素含量均有较大的变化,其中樟树茎流中Zn,SiO2,Fe,Cu;火炬松、槲栎茎流中Zn,Fe;醉香含笑茎流中Zn为负淋洗,4个树种对Zn的负淋洗表现的尤为显著.     

油茶林果实成熟期养分分配特征

以常宁市10年生油茶作为试材,对油茶养分分配规律、油茶林土壤养分与树体各器官营养元素含量的相关性进行研究,旨在为油茶营养诊断以及配方施肥提供科学依据。结果表明:油茶各器官中,大量元素含量由高到低排序依次为N、Ca、K、Mg、P,微量元素含量由高到低排序依次为Mn、Fe、Pb、Zn、Cu、Cd;土壤大量元素含量由高到低排序依次为Ca、N、K、P、Mg,微量元素含量由高到低排序依次为Fe、Pb、Zn、Cu、Mn、Cd。土壤养分含量与油茶各器官养分指标具有不同程度的相关性,与油茶干的养分含量相关性最为紧密;土壤N、Zn、Mn、Pb、K含量与油茶植株养分元素含量的关系最为紧密;土壤Mn与油茶各器官Mn元素含量均呈现正相关;土壤N与油茶干中N含量呈现极显著相关;土壤Cd元素含量和油茶各器官中Cd元素含量多存在负相关性。     

江汉平原连栽杨树人工林对土壤化学性质的影响

采用空间代替时间的方法,研究了连栽对江汉平原杨树人工林土壤化学性质的影响.结果表明:与第1代林相比,第2代林土壤pH值有所提高,有机质、大量元素及微量元素等养分含量均有不同程度下降,其中pH值提高了2.42%,有机质降低了4.65%;连栽导致N、P、K大量元素下降了2.88%～12.20%,且对N影响最大,K次之,P最小,土壤N、P、K养分库有效性指数下降了3.82%;连栽导致微量元素下降了2.27%～53.37%,且对Zn影响最大,其后依次是Cu、Fe、Mn和S,土壤微量元素有效性综合指数降低了12.51%.     

连栽马尾松林根际与非根际土壤养分及酶活性研究

通过配对样地法,对连栽马尾松林根际与非根际土壤养分及酶活性的差异性进行分析。结果表明:根际与非根际土壤全N、全K、全Ca和全Mg含量2代低于1代,而有机质、碱解N、速效P、全P和速效K含量2代却高于1代,且有机质、碱解N和速效P含量在1、2代之间的差异均达显著或极显著水平;连栽后根际土壤全Al、全Cu和全Zn含量2代高于1代,而全Fe和全Mn含量2代却低于1代,且全Mn含量在1、2代之间的差异达显著水平;非根际土壤除全Cu含量2代高于1代外,其余全Fe、全Al、全Zn、全Mn含量2代均低于1代,且差异均达显著或极显著水平;根际与非根际土壤脲酶、蛋白酶、磷酸酶、过氧化氢酶和多酚氧化酶活性2代均高于1代,且脲酶、磷酸酶、过氧化氢酶活性在1、2代之间的差异均达显著或极显著水平。     

森林草原交错区沟塘草甸土壤微量元素分析

为研究森林草原交错区不同坡向沟塘草甸土壤化学计量特征,以内蒙古阿尔山市的沟塘草甸为研究区域,通过野外调查与室内实验相结合的方法,对阴坡阳坡不同深度土层有效微量元素(Fe,Mn,Cu,Zn)含量及有机C,全N,全P含量进行比较分析,探究沟塘草甸土壤化学计量特征。结果表明:1)阴坡阳坡土壤有效Fe和有效Mn含量均随着土层深度增加呈现先增后减趋势,而有效Cu含量随着土层深度变化差异不显著;2)阴坡阳坡土壤有效微量元素含量均呈现Fe>Mn>Zn>Cu趋势;3)土壤有效微量元素含量与pH值无相关性,有效Fe含量与有效Mn、有效Cu、有效Zn含量相关性(P<0.01)极为显著;4)同一坡向不同深度土层C∶N,N∶P差异均不显著,而C∶P差异显著;5)土壤pH在不同坡向不同深度土层均无显著差异。研究结果为沟塘草甸土壤微量元素分析提供数据支持。     

不同浓度氨源引起的红松苗木根际pH变化及其对Fe、Mn、Cu、Zn有效性和吸收的影响

Dark brown forest soil was collected from the upper 20 cm soil layer in Changbai Mountain Research Station of Ecosystem, Chinese Academy of Sciences. The soil was amended with two different forms of nitrogen fertilizers: NO₃ as Ca(NO₃)₂, NH₄ ⁺ as NH₄Cl at the concentrations of 50, 100, 200 and 400 mg kg⁻¹respectively. The experiment was carried out with 2-yr-oldPinus koraiensis seedlings in pot. The pH change of rhizosphere soil and the contents of available Fe, Mn, Cu, and Zn in soil and leaves were analyzed. The result indicated that the addition of NH₄-N decreased the rhizosphere pH value, while the addition of NO₃-N increased the rhizosphere pH value in contrast with the control treatment. The direction and extent of the pH change mainly depended on N source and its concentrations applied. The rhizosphere pH change had a remarkable influence on the availability of the micronutrients in the rhizosphere, and thereafter affected the nutrient uptake by the seedlings. The contents of available mineral nutrients had a negative correlation with the pH value in the rhizosphere soil. The contents of available mineral nutrients in leaves were positively correlated to the levels of the available nutrients in the rhizosphere soils. Foundation item: This paper was supported by National Natural Science Foundation of China (Grant No. 30170167). Biography: CHEN Yong-liang (1969-), male, Ph. Doctor, lecture of Northeast Forestry University, Harbin 150040, Post-doctor in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China. Responsible editor: Song Funan     

氮肥对盆栽欧洲水青冈生物量和营养分配的影响(英文)

调查了施加氮肥(15NH4和15NO3)处理后在两个连续生长季内欧洲水青冈(Fagus sylvatica L.)幼苗地上部分和地下部分的生物量和营养元素分配。盆栽欧洲水青冈幼苗培养于温室大棚内,培养土样取自相邻的三种林分:欧洲水青冈,挪威赤松,欧洲水青冈-赤松混交林。结果表明,氮肥(15N)处理对欧洲水青冈营养元素分配没有显著影响,施加氮素形式决定自身流入植物库的情况。欧洲水青獭收氮素主要以硝态氮的形式,因此,尽管植物体内保存的硝态氮和氨态氮并没有统计差异,但是叶片中硝态氮明显减少。施加硝态氮对欧洲水青冈氮素恢复的影响要大于施加氨态氮。与欧洲水青冈茎、粗根相比,优质根系对氮素(15N)固定是一个缓慢过程。表8图1参40。     

Growth and mineral nutrition of Gmelina arborea Roxb. seedlings fertilized with four sources of nitrogen on a latosolic soil

The growth and mineral nutrition of Gmelina arborea Roxb. seedlings were investigated in response to four nitrogen-based fertilizers applied at 0, 2.5, 5.0 or 7.5 g N per plant. Nitrogen sources included NH(4)-N as ammonium sulfate, NO(3)-N as potassium nitrate, NH(4)NO(3)-N as calcium ammonium nitrate, and urea-N as urea. Seedlings fertilized with NH(4)NO(3)-N or urea-N had greater height, collar diameter, dry weight, net assimilation rate, and relative growth rate than seedlings fertilized with NH(4)-N or NO(3)-N. For all sources of nitrogen, increasing the amount of exogenously supplied N per plant promoted shoot growth more than root development, hence the root to shoot ratios of all fertilized seedlings were smaller than those of the unfertilized controls. Applications of NO(3)-N increased the nitrogen, potassium, and phosphorus concentrations of fertilized seedlings. Regardless of source, a nitrogen application of 2.5 g N per plant was apparently optimal for the growth of Gmelina seedlings on a latosolic soil.     

红心杉根际土壤与非根际土壤养分差异研究

对江西省南昌市湾里区红心杉林根际土壤与非根际土壤养分差异进行研究。结果表明:不同年龄的红心杉林分,其根际土壤与非根际土壤的养分均存在差异,林分年龄与土壤类型的交互效应均极显著。pH和有效磷、有机质含量在林分年龄和土壤类型间都存在极显著差异;碱解氮、全氮、速效钾含量在林分年龄间存在极显著差异,在土壤类型间无显著差异;全磷含量在林分年龄间存在极显著差异,在土壤类型间存在显著差异。红心杉非根际土壤的养分在20、40年生的变化很小,而根际土壤的全氮、全磷、速效钾含量差异仍然明显。     

Nitrate content, amino acid composition and growth of yellow birch seedlings in response to light and nitrogen source

Yellow birch (Betula alleghaniensis Britt.) seedlings were grown for three months in a greenhouse at two radiant flux densities-full light (FL) and 50% shade (LL)-and with three nitrogen sources- ammonium only (NH(4) (+)), nitrate only (NO(3) (-)) and a 1:1 mixture of ammonium and nitrate (NH(4) (+)/NO(3) (-))-in a completely randomized factorial design. The total biomass of seedlings grown under low light (LL) did not vary significantly with nitrogen source; although NO(3) (-)-treated seedlings were smaller and had a significantly lower (P 相似文献   

不同林龄湿地松土壤养分状况分析

不同林龄（5、10、15及20年生）湿地松人工林土壤养分（铵态氮（NH4^＋-N）、硝态氮（NO3^--N）、有效磷（P）、有机质及pH变化规律的研究结果表明：随林龄增长,土壤速效N（NH4^＋-N＋NO3^--N）含量呈增加趋势;有效P及有机质含量则随林龄增加而降低,但后者在后期略有增加;土壤pH值随林龄增长先上升后降,几种土壤养分的层次差异均较为明显（上层含量高于下层）,有必要施入磷肥和石灰进行土壤改良。     

Absorption and assimilation of nitrate and ammonium ions by jack pine seedlings

Jack pine (Pinus banksiana Lamb.) seedlings were grown in a shaded or unshaded light regime with either NO(3) (-)- or NH(4) (+)-N as the sole N source. After three months, seedlings grown with NH(4) (+)-N were larger than seedlings grown with NO(3) (-)-N. Irradiance had a greater effect on growth of ammonium-fed seedlings than on growth of nitrate-fed seedlings.At all times from 6 to 24 h following incorporation of (15)N, soluble, insoluble, and total (15)N contents of shoots and roots were higher in ammonium-fed seedlings than in nitrate-fed seedlings. The pattern of (15)N accumulation in shoots was similar to that in roots. After 6 and 24 h of (15)N incorporation, unshaded, ammonium-fed seedlings had 8.8 and 2.8 times greater total (15)N contents, respectively, than unshaded, nitrate-fed seedlings. In response to shading, ammonium-fed seedlings increased their total uptake of (15)N per unit root weight, whereas nitrate-fed seedlings did not. No nitrate or (15)NO(3) (-) was detected in any plant tissue. Nitrate-fed plants had higher NH(4) (+), Asp, and Gln concentrations in needles and higher gamma-aminobutyric acid and Arg concentrations in stems. Accumulation of (15)N in roots was not affected by the pH of the (15)N solution or by the N source fed to the seedlings before the period of (15)N incorporation. Thus NO(3) (-) transport into roots, rather than its reduction or transport within the plant, seems to be the factor limiting the growth of jack pine supplied with NO(3) (-)-N as the sole N source.     

果园微气候及土壤养分对灰枣果实矿物元素含量的影响

为了遴选出影响灰枣果实矿物元素形成的关键因子,分别设计了树体阴阳面、遮阳、喷水及地表覆盖物等果园微气候处理方式,就不同处理下的气象因子及土壤碱解氮(N)、速效磷(P)、速效钾(K)、有机质(OM)及酸碱度(p H)对灰枣果实中的钙(Ca)、镁(Mg)、铁(Fe)、锌(Zn)、锰(Mn)和铜(Cu)等矿物元素的影响情况进行了试验,并采用显著性、通径系数及线性回归等分析方法,探究了枣果中矿物元素含量与气象因子及土壤养分因子之间的关系。结果表明:在一定范围内,p H值的升高,有利于枣果中Mg和Mn含量的增加;平均湿度相对较高,对枣果中Fe的含量有促进作用。土壤N含量能有效增加枣果中Cu的含量;枣果Ca含量的影响因素依次为平均湿度差、OM、N、平均最低温度及平均最小湿度,Ca含量与OM和平均最低温度间均有负相关,而与其他指标间均呈正相关;影响枣果Zn含量的因素依次为N、平均最低温度、平均湿度差、平均温度差和OM,其中Zn含量与N和OM间均存在负相关,而与上述其余各指标间均呈正相关。     

Effects of nitrogen source and defoliation on growth and biological dinitrogen fixation of Gliricidia sepium seedlings

Effects of four N sources and two defoliation treatments on growth and nitrogenase activity of Gliricidia sepium (Jacq.) Walp seedlings were studied in a greenhouse. All nutrients were supplied in irrigation water to the sterile growing medium. The N sources were: (1) 100 mg l(-1) of N supplied as NO(3) (-) (high-NO(3) (-)), (2) 50 mg l(-1) of N supplied as NO(3) (-) and inoculation with Rhizobium spp. medium-NO(3) (-)), (3)100 mg l(-1) of N supplied as NH(4)NO(3), and (4) inoculation with Rhizobium spp without mineral N (N(2)). At 35 weeks after sowing, mean total biomass was 130.5, 50.5, 22.9 and 17.4 g seedling(-1) in the NH(4)NO(3), N(2), medium-NO(3) (-) and high-NO(3) (-) treatments, respectively. The root/shoot ratio was high in all of the N treatments (1.73-2.77) because the seedlings had big taproots. The medium-NO(3) (-) treatment completely inhibited nodulation, whereas seedlings in the N(2) treatment were profusely nodulated. At 32 weeks after sowing, groups of seedlings in the N(2) and high-NO(3) (-) treatments were subjected to 50 or 100% defoliation. Closed-chamber acetylene reduction assays of intact root systems were conducted to compare nitrogenase activity at 7, 14 and 28 days after defoliation (DAD). At 7 and 14 DAD, nitrogenase activity of completely and partially defoliated seedlings was about 10 and 60%, respectively, of that of undefoliated controls. At 28 DAD, nitrogenase activity of completely defoliated seedlings was twice the predefoliation value, whereas nitrogenase activity of partially defoliated seedlings was only 87% of the predefoliation value. Recovery of nitrogenase activity was strongly correlated with foliage regrowth in the completely defoliated seedlings, but not in the partially defoliated seedlings. Abundant belowground C and N reserves in the large taproot probably contributed to the rapid recovery from defoliation. Accumulation of belowground biomass may also improve defoliation tolerance of mature trees.