氮添加对兴安落叶松养分分配和再吸收效率的影响

以东北林业大学帽儿山实验林场18年生兴安落叶松人工林为对象,研究连续5年N添加(NH4NO3,10g·m-2a-1)对落叶松各器官N,P,K,Ca和Mg含量及叶片养分再吸收效率的影响。结果表明:N添加对叶片5种元素含量均无显著影响,但可显著提高树根、树枝和树干的N和P含量;N添加能显著提高凋落叶片的N含量,降低凋落叶片的C/N比和叶片N再吸收效率。研究结果反映出研究区兴安落叶松人工林土壤N并不缺乏。N添加导致兴安落叶松对N和P的奢侈吸收,可提高凋落物的分解速率,加快兴安落叶松人工林生态系统的N循环。     

PT菌剂对兴安落叶松苗木生长的影响

菌根能促进植物的生长 ,并提高苗木质量、作物产量和造林成活率。目前 ,在实践中真正应用的主要有美国、中国、法国和加拿大等国家。 PT菌根制剂是由中国林科院林木菌根研究开发中心研制的 ,已形成规模化产品 ,多应用在我国的南方。为了研究菌根菌对寒温带针叶林区主要造林树种——兴安落叶松 ( Larix gmelinii)的影响 ,1997～1998年大兴安岭林科所对兴安落叶松开展了菌根菌 ( PT菌剂 )在育苗技术上的应用研究 ,现将结果简介如下。1　材料与方法1.1　材料来源供试菌种为 910 1菌根真菌活体制剂及910 3菌根真菌次生代谢产物制剂 ,这两类制…     

混沙改土对兴安落叶松苗木生长的影响

混沙改土对兴安落叶松苗木生长的影响于常惠（大兴安岭图强林业局资源科）杜小光王洪彬（大兴安岭林管局林科所）齐华生（大兴安岭十八站林业局规划队１试验地概况试验分别于１９９５年秋季和１９９６年春季在大兴安岭林管局林科所苗圃内进行。该苗圃位于加格达奇南１５ｋ...     

CO2浓度升高对植物生长和N吸收及代谢的影响

指出了随着大气中的CO2浓度不断升高,对陆地生态系统造成一定的影响,从植物的生长、植物N素吸收、植物及代谢酶等方面详细地探讨了CO2浓度对植物的影响。     

不同N素形态对落叶松苗木根/土界面pH值及养分有效性的影响

尽管根/土界面一般是指根围数毫米范围内的微域土区,但该微区中物理、化学和生物学状况直接影响着土壤中水分、养分的向根迁移、转化和有效性,影响着植物根的吸收和生理活性(刘芷宇等,1997),因此对于该微区的研究在理论与实践上都具有极为重要的意义.     

养分含量对闽楠苗木生长的影响

试验结果表明,闽楠苗木根、茎及叶中的N、P、K和Ca的含量存在着显著差异,其中叶片中各种元素的含量最多。如果土壤中N、P含量太低将导致闽楠苗木的吸收量不足而使苗木生长较差,当土壤中的养分含量达到一定量时,特别是全N、速效P的含量分别达到0.1%和20.3×10-6时,就能满足闽楠苗木生长的需要,且苗木的吸收量不随土壤中养分含量的变化而变化。在闽楠苗木的年生长期中,苗木的N、P、K和Mg的含量随着时间的变化而变化,一般是6月份最高,以后逐渐下降,秋季再出现一次高峰。     

氮、磷、钾配比施肥对辣木生长及叶片养分吸收的影响

[目的]为明确辣木生长对养分的需求及叶片养分吸收状况。[方法]研究采取田间小区实验,设置N_(80)、N_(80)P_(20)、N_(80)K_(40)、P_(20)K_(40)、N_(80)P_(20)K_(40)、N_(60)P_(20)K_(60)和不施肥对照7个处理,测定分析不同氮、磷、钾配比施肥对辣木生长及叶片养分吸收的影响。[结果]不同氮、磷、钾配比施肥处理下,辣木生长速度先快后缓慢,处理90 d后株高、冠幅和鲜叶生物量的最高值及地径的次高值均出现在N_(80)中,N_(60)P_(20)K_(60)的株高、地径及N_(80)K_(40)的鲜叶生物量仅次于N_(80)处理;不同氮、磷、钾配比施肥均促进了辣木叶片中全氮、全磷含量的累积,但降低了全钾含量;除N_(80)外,其它处理叶片叶绿素含量均低于CK,高氮处理的叶绿素含量均高于P_(20)K_(40)和N_(60)P_(20)K_(60),N_(80)P_(20)高于N_(80)K_(40)。[结论]各元素对辣木生长影响大小为NKP,对叶片中叶绿素含量影响大小为NPK,叶片中营养元素含量大小为NKP。综合试验结果中辣木主要生长指标的生长及叶片养分吸收情况,配比施肥最优处理为N_(80),且该施肥处理主要适用于辣木幼龄及速生生长阶段。     

不同基质对浙江樟幼苗生长及养分吸收的影响

浙江樟(Cinnamomum chekiangense)是重要的珍贵树种,在大力推广珍贵树种造林中,优质容器苗的培育是造林成功的关键,而育苗基质直接决定着苗木质量.本文以浙江樟1年生苗为研究对象,采用盆栽的方法,研究5种不同配比基质(黄泥、锯末、泥炭)对苗木株高、地径、生物量的生长和氮磷钾养分积累的影响,旨在筛选出适合...     

不同氮磷钾配比对油松幼苗生长和养分吸收的影响

通过研究氮磷钾不同施用比例对油松生长和养分吸收的影响规律,可为油松育苗中科学施肥提供理论依据。在田间条件下,以1年生油松实生苗为试验材料,设置氮磷钾施用比例分别为1∶0∶0(T₁,CK);1∶1∶0.5(T₂);1∶0.5∶1(T₃);1∶1∶1(T₄)共4个处理,3次重复。结果表明：T₂与CK、T₃相比显著提高了叶绿素含量,T₄与T₂之间无显著差异;T₂株高和地径分别比对照提高了37.90%和30.09%,T₂显著高于T₃,T₄与T₂之间无显著差异;T₂根、茎、叶、总干物质积累量分别比对照提高了22.74%、9.50%、61.02%、38.55%,氮吸收量分别提高了28.90%、19.94%、65.90%和55.58%,磷吸收量分别提高了34.23%、34.77%、82.31%和6...     

Effects of different N sources on growth, nutrient uptake and ionic balance ofLarlix gmelini seedlings

The effect of different sources and levels of N on dry matter production, nutrient uptake and ionic balance ofLarlix gmelini was studied. The results showed that the growth of the plants fertilized with ammonium was not as good as the control treatment. The growth of the plants fertilized with ammonium nitrate did not differ significantly from that in control or nitrate treatment, but was better than that in the ammonium treatment. Total cation concentrations in shoots varied little with N level in the ammonium and ammonium nitrate treatments, while those in the shoot increased with N level in the nitrate treatment. The treatments had little effect on the anion concentrations in the shoot. In the roots, the concentrations of both cations and anions changed little except for SO₄ ²⁻ and Ca²⁺. There existed a higher carboxylate production in the plants fertilized with nitrate. The ratio between the production of carboxylate and the production of organic N Δ(C-A)/ΔN_org was constant with N supply in the plants receiving nitrate, but obviously declined with N supply for ammonium-fed plants. Δ (C-A)/ΔN_org values were intermediate between those of the nitrate and the ammonium-fed plants as for the mixed N source. Foundation item: This paper was supported by “Hundred Scientists” Project of Chinese Academy of Sciences. 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 Fuman     

Source of mycorrhizal inoculum influences growth of Faidherbia albida seedlings

Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.     

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     

不同浓度氮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(英文)

在中科院长白山生态系统定位站,从地表20cm处采集土壤样品,用两种不同形式的氮肥(NO3--N,NH4 -N和NH4NO3)处理土壤样品,用盆栽试验研究了两年生红松苗木受不同浓度N源影响而产生的根际pH变化及其对根际Fe、Mn、Cu和Zn等微量元素的有效性和吸收的影响。结果表明,与对照处理相比,施加铵态氮使根际pH降低,而施加硝态氮则使根际pH增加。根际pH变化的方向与程度取决于N源及施加的浓度。根际pH的变化对根际微量元素的有效性具有显著影响,进而影响到苗木对养分的吸收利用。根际有效Fe、Mn、Cu和Zn的含量与根际pH呈负相关,而苗木叶中Fe、Mn、Cu和Zn含量与根际有效养分含量呈正相关。图5参11。     

Nitrogen and phosphorus leaching and uptake by container birch seedlings (Betula pendula Roth) grown in three different fertilizations

Leaching of nitrogen (N) and phosphorus (P) through container peatmedium and N and P uptake by seedlings were determined in commercial productionof birch grown with three different types of fertilization. Half of the amountof nutrients was premixed into the peat medium and the other half was appliedasliquid (=fertigated) in the treatment (PF) commonly used in Finland. In twoother treatments all nutrients, either totally (P-VN) or partly (P-N) inslow-release form, were premixed into the peat. Independently of the treatment,the largest proportion (60 to 80%) of total N leached during May and June.During two growing seasons, the amounts of N leached from PF treatments (9 to36kg ha^–1) were as large as the amounts of Nleachedfrom P-VN and P-N treatments (24 to 46 kg ha^–1).Due to fertigations between container trays, however, the total N load perhectare was greatest in the PF treatments. In the soil water 0.5meter beneaththe container area, the N concentration varied from 10 to 60 mgl^–1. The morphological and chemical properties of theseedlings did not differ greatly between treatments.     

Effects of soil temperature on shoot and root growth and nutrient uptake of 5-year-old Norway spruce seedlings

Soil temperature is a main factor limiting root growth in the boreal forest. To simulate the possible soil-warming effect of future climate change, 5-year-old Norway spruce (Picea abies (L.) Karst.) seedlings were subjected to three simulated growing seasons in controlled environment rooms. The seedlings were acclimated to a soil temperature of 16 degrees C during the first (GS I) and third growing seasons (GS III), but were assigned to random soil-temperature treatments of 9, 13, 18 and 21 degrees C during the second growing season (GS II). In GS II, shoot diameter growth was lowest in the 21 degrees C treatment and root growth was lowest in the 9 degrees C treatment. In GS III, shoot height and root length growth improved in seedlings that had been kept at 9 degrees C during GS II, indicating compensatory growth in response to increased soil temperature. The temporary decrease in soil temperature had no long-lasting significant effect on seedling biomass or total nutrient uptake. At the end of GS III, fine roots of seedlings exposed to a soil temperature of 21 degrees C in GS II were distributed more evenly between the organic and mineral soil layers than roots of seedlings in the other treatments. During GS II and GS III, root growth started earlier than shoot growth, decreased during the rapid shoot elongation phase and increased again as shoot growth decreased.     

Long-term prescribed burning increases nutrient uptake and growth of loblolly pine seedlings

Loblolly pine (Pinus taeda L.) seedlings were grown from seed in a greenhouse on A1 horizon soil collected from field plots that have been burned each winter or maintained in an unburned condition for 33 years. Soils from burned and unburned plots were treated with phosphorus (P), P and calcium (Ca), or left untreated. After 32 weeks, height, biomass, and nitrogen (N) and P uptake were greater on soil from burned versus unburned plots, although application of P masked these effects. Addition of P increased plant biomass, seedling height, and uptake of N and P, but depressed levels of soil NH₄N. These results suggest that long-term prescribed burning may have a positive effect on nutrient availability that will benefit seedlings of the next stand.     

大量元素缺乏对樟树幼苗生长的影响

为探讨不同营养元素缺乏对樟树幼苗生长的影响,以樟树当年生幼苗为材料,设置全素、缺N、缺P、缺K、缺Mg 5个处理,观测其营养缺乏症状及生长状况.结果表明:樟树幼苗缺N时症状出现较早,表现最为明显,其叶片偏小、变黄绿色,整株矮小,长势较弱,其次为缺Mg,而缺P和缺K幼苗症状出现缓慢,表现相对不明显.不同缺素处理的樟树幼苗的苗高、地径、各组织生物量、主根长、侧根数量和叶面积均显著低于全素处理(P<0.05),其中缺N影响最大,其次为缺Mg处理.缺素处理增加了幼苗叶生物量比,降低了根生物量比和根冠比,其中缺Mg对根系生长影响最大.因此,N和Mg是限制樟树幼苗生长的主要影响因子,在樟树苗期营养管理中,应及时施用N肥,并保证Mg、P和K肥的供应.     

Rock phosphate and vesicular-arbuscular mycorrhiza effects on growth and nutrient uptake of Faidherbia albida (Del.) seedlings in an alkaline sandy soil

Response of Faidherbia albida (Del.) to five levels of Kodjari rock phosphate (KRP) application (0, 310, 620, 1240 and 2480 ppm P, equivalent to 0, 775, 1550, 3100 and 6200 kg P/ha) and vesicular-arbuscular mycorrhizal fungi (VAMF) Glomus manihotis Howeler, Sieverding & Schenck or Glomus aggregatum Schenck & Smith emend. Koske was evaluated in an alkaline sandy soil. The F. albida seedlings grew poorly without mycorrhizal colonization and without KRP applications. For non-VAM Faidherbia, the maximum growth response and both P and N uptake in shoots was achieved with the 620 ppm P. However, even without KRP application, VAM plants achieved better results in terms of biomass. VAM plants with G. manihotis and G. aggregatum improved plant growth and increased nutrient contents at any KRP application rate. Although mycorrhizal colonization was comparable at all levels of KRP application, the impact of nutrient content of the shoot varied. Finally, VAM plants did not accumulate more biomass than non-VAM plants at 620 ppm P and above. Growth response and mycorrhizal dependency decreased as KRP applied levels increased. These results suggest that VAM Faidherbia seedlings take up more P from soil and KRP than non-VAM.     

The influence of different forest organic matter on the growth of one-year old planted Norway spruce seedlings in a greenhouse experiment

A greenhouse trial was carried out to improve the knowledge of how forest organic matter could be utilized in site preparation and the choice of planting spot for Picea abies (L.) Karst. One-year old Norway spruce seedlings were grown for 26 weeks in pots containing pure mineral soil, forest organic matter in three different states of decomposition and combined treatments where the organic matter was mixed with or placed on the surface of the mineral soil (volume proportions of organic:mineral of 1:2). Watering was adapted to the water retention characteristics of each growing medium in order to keep the soil water potential between -4 and -5 kPa in all pots.In its pure form as well as combined with mineral soil, the moderately decomposed mor organic matter gave a higher seedling dry weight increment than the corresponding growing media containing the more decomposed humus. Adding mor or humus to mineral soil increased the seedling dry weight increment by 30–140% and 10–40%, respectively. The largest seedlings grew in the pure mor and humus. Mixing these forms of organic matter with mineral soil appeared to reduce seedling growth as compared to placing them on the mineral soil surface. The increment increase compared to plain mineral soil mostly consisted of proleptic growth and was probably due to the improved nutrient availability of the growing media. Fresh organic matter (chopped needles and twigs) seemed to impair seedling root function and reduced the dry weight increment by 30–50% as compared with pure mineral soil.The results suggest that as long as the water and temperature requirements are fulfilled planting Norway spruce seedlings without scarification and/or gathering extra mor and humus to the planting position should improve seedling growth as compared to the growth following scarification. Unmixed fresh needles and twigs or fresh needles and twigs combined with plain mineral soil should be avoided when planting Norway spruce seedlings.