Root secretion stimulating ash growth in larch-ash mixed forest

IntroduchonRePOrt6d as early as 1920s, the groWth of ashcould be increaSed as ash was mixed with larch.However, the mechanism of allelopathic effect betwedn larch and ash has not been clearly yet. Theallelopathic ~ in mixed forest were generallyregard6d as fOllowing four wayst volatile matt6rs, rootsecredon, St6m leaching, and litter decompositionmatt6rs (Zhai 1993). This paper presented the studies on the ~ of root secretion, focused on thosestimulahon allelochemicals that can increase the…     

落叶松水曲柳纯林与混交林根际土壤中养分浓度的变化

在落叶松水曲柳纯林与混交林中,采集林地土和根际土,测定了氮、磷、钾浓度,目的是探讨养分条件变化在混交林增产上的作用。结果表明:混交林林地土全氮浓度和水解氮浓度与水曲柳纯林相近,但要高于落叶松纯林。水曲柳在混交林中根际土全氮和水解氮浓度与纯林中的相近,而落叶松在混交林中根际土水解氮浓度明显高于纯林中的。混交林林地土全磷和全钾浓度与两个树种的纯林相差不大。混交林林地土有效磷、有效钾浓度均高于水曲柳纯林,而且水曲柳在混交林中根际土的有效磷和有效钾浓度与纯林中的相比明显增加,分别高出44.1%~79.6%和13.5%~25.6%。这说明水曲柳在混交林中磷和钾的利用状况得到了改善。表2参15。     

THE CHARACTERS AND EFFECTS OF AVAILABLE PHOSPHORUS IN DAHURIAN LARCH-MANCHURICA ASH MIXED SEEDLING STAND

Dahurianlarch(Larixgmelinii)isamaintreesPeciesinartificialstandsandManchuriaash(Fnainusma:dehurica)isavaluabIehardwoodsPeciesinti1eforestareaofnortheastChina.SomestUdiesrevealedthatthemixedstandbythetwospecieshadpositivemixedeffectSandnutritionrelationshipwasoneofthemaincausesforthepositiveeffects.lnsomeresearches,itwasfoundthatinline-belttwoflarch-ashmixedstand,theconcentra-tionofavailablephosphorusofsoilinlarchbeltwas2ntimesoftl1atinashbelt.Itisdeducedthatinsuchmixedstandtheashcanabsorbmo…     

水曲柳落叶松混交林中细根空间分布

采用根钻取样方法对年生水曲柳落叶松混交林中细根空间分布状况进行了研究。结果表明,水曲柳落叶松地下生物量的空间分配差异显著。在林分水平上,水曲柳的根生物量密度高于落叶松(分别为4442.3和2234.9g/m3)。两树种在相邻区域中分配的细根生物量较高,表明种间根系竞争较弱。落叶松行间的水曲柳细根生物量密度和根长密度均高于水曲柳行间的落叶松细根,表明水曲柳地下部分具有较强能力。根系的空间分布有利于混交林中水曲柳的生长。图1表4参19。     

Photosynthetic Characteristics of Ash and Larch in Mixture and Pure stands

IntroductionDuringthepasttwodecades,studieshaverevealedthatgrowingash(Fnainusmandshurica)andlarch(LarlksPP.)togetherinaproperwaycanincreasetheproduc-tivityQfthestandsI"'}'-'].Theyieldimprovementmechanismsattributetotwoaspects,i.e.,theabovegroundandundergr…     

Quantitative analysis for interspecific relationship of larch stand mixed with ash

Lastvears.manvrescarchaboutintcr-sPecificrclationshipofmixcdstandsforIarchandasht`crcrePeatcd,mostof\`tich,hot`cvcr,isfortheplantingtypeoflinc-bclt.Thispaperanalysisash-larchrclationshipfor26agcdartificialIarchstandmixedwithcvenagcdashinnaturalreqencration.SlTEANDMEASUREMENTMETHOl)ArtincialIarchstandmcasuredlocatcdatecologicaIcxPCrimcntstationinMaocrshanMountainForcstryFarmofNortbcastForcstryUnivcrsity'(El27'34',N45"24').LarchttasplantcdonagrcatPCaccofdescrtcdfieIdinl967t"itha…     

燕山北部山地人工落叶松林与天然次生林物种多样性的比较

为了解燕山北部山地华北落叶松人工林植被物种多样性维持功能的高低,选取13a和30a生人工落叶松林,以13a和28a生天然次生杨桦林作为对照,对两种林分的植被多样性进行调查和分析,并研究了间伐对人工落叶松林植被物种多样性的影响。结果表明,林龄相同或相近的两种林分类型相比,无论是乔木层、灌木层或是草本层,人工落叶松林丰富度、Simpson指数、Shannon—Weiner指数均表现出相当或略高于天然次生杨桦林（30a生人工落叶松林乔木层多样性指数除外）;间伐对人工落叶松林植被物种多样性的短期影响主要体现在乔木层,对林下灌木层和草本层无明显影响。燕山北部山地人工落叶松林具有较高的植物多样性维持功能,没有导致物种多样性的降低。     

GROWTH EFFECT OF DAHURIAN LARCH-MANCHURIAN ASH MIXED FORESTS

STUDYAREAANDareTH0DThestUdyareawasatthecompatheentllofXinkenIllWorkingUnitinchoershanExPenmentalForestFann,NortheastF0restryUniversity.Dunngthespnngofl967,Dahu-nanlarchwasplantedintheleftlandofsecon-daryf0rest.Beforeorafterplanhng,mal1yMancl1tlrial1ash,e1l11withwhitebarkandsolneotherbroad-leavedtLreesinvadedandgrewwell.NowManchunanashandDahu-nanlarchn1ixedforestshavebeenf0n11ed,inwhichManchurianashisdolninant.lnl984,2Pen1lanentplotsweresetupwiththeslzeof0.O6hnl',facil1gsoutheast,…     

STUDY ON THE NATURAL REGENERATION EFFECT OF MANCHURIAN ASH BY OPENING UP EFFECT BELT IN DAHURIAN LARCH PLANTATION

NaturalregenerationofmanchurianashusuallytakesplacewheretherearesuitablesoilmoistureandseedbankofsecondarymanchurianashforestintheEasternMountainousAreaofNortheastChina.Sometimes,naturalregenerationofmanchurianashcanbefoundinpureconiferousplantation.Inordertofindoutthepossibilityofintroducingnaturalregenerationofmanchurianashinpureconiferousplantation,trialsandresear-cheshavebeencarriedoutindahurianlarchp1antationbyopeningupeffectbeltinthestands.lntheend,charactersofcommunitystructureandmicr…     

Carbon dioxide exchange of a larch forest after a typhoon disturbance

A typhoon event catastrophically destroyed a 45-year-old Japanese larch plantation in southern Hokkaido, northern Japan in September 2004, and about 90% of trees were blown down. Vegetation was measured to investigate its regeneration process and CO₂ flux, or net ecosystem production (NEP), was measured in 2006–2008 using an automated chamber system to investigate the effects of typhoon disturbance on the ecosystem carbon balance. Annual maximum aboveground biomass (AGB) increased from 2.7 Mg ha⁻¹ in 2006 to 4.0 Mg ha⁻¹ in 2007, whereas no change occurred in annual maximum leaf area index (LAI), which was 3.7 m² m⁻² in 2006 and 3.9 m² m⁻² in 2007. Red raspberry (Rubus idaeus) had become dominant within 2 years after the typhoon disturbance, and came to account for about 60% and 50% of AGB and LAI, respectively. In comparison with CO₂ fluxes measured by the eddy covariance technique in 2001–2003, for 4.5 months during the growing season, the sum of gross primary production (GPP) decreased on average by 739 gC m⁻² (64%) after the disturbance, whereas ecosystem respiration (RE) decreased by 501 gC m⁻² (51%). As a result, NEP decreased from 159 ± 57 gC m⁻² to −80 ± 30 gC m⁻², which shows that the ecosystem shifted from a carbon sink to a source. Seasonal variation in RE was strongly correlated to soil temperature. The interannual variation in the seasonal trend of RE was small. Light-saturated GPP (P_max) decreased from 30–45 μmol m⁻² s⁻¹ to 8–12 μmol m⁻² s⁻¹ during the summer season through the disturbance because of large reduction in LAI.     

EFFECT OF FERTILIZATION ON THE GROWTH OF LARCH SEEDLINGS

The primary purpose of fertilization in nursery soils is to assure production ofhigh—quality planting stock. Therefore,the appropriate information on fertilizers and their use aswell as their effects on seedling growth is important to nursery managers in their nursery practice.Inthis paper,larch seedling growth response to six fertilizers are discussed based on the results ofthree—year studies which were carried out at Dailing Forest Nursery in 1987.     

Growth effect of Manchurian ash in mixed stands

lntroductionThepIantingofFraxiusm8ndShurfoabeganatShangzhi,Kedong,YianandFujincountiesofHei-longjiangProvincein196o'.Ash(hainusmand-shurica)andlarch(LarisgmehnI),AshandKoreanpine(PinuskoraiensiS)mixedstandwereremainednow,whichwereartificial,orformedbyplantingAshatterpIantingpureconiferousforest,orinducedbyestablishingeffectareainnaturalashforest.TherearemanyreferencesonthegrowthofashmixedstandinChina.Butinthepast,thestudyoftherela-tionshipbetWeentheincreasinggrowthofmixedstandwithdiffe…     

Canopy leaching of subtropical mixed forests under acid rain

Leaching of major ions from acid precipitation in a subtropical forest was examined based on an experiment in four sample sites in Shaoshan City, Hunan Province, China, from January 2001 to June 2002. Results clearly show that when rain passed through the canopy, pH increased and the evidence of ion uptake was presented for SO₄ ²⁻, NO₃ ⁻, Mg²⁺ and NH₄ ⁺ ions, especially of NH₄ ⁺ and NO₃ ⁻. The percentages of dissolved SO₄ ²⁻, Ca²⁺ and Mg²⁺ show a decreasing trend with increasing rainfall. Percentages of leaching Ca²⁺, K⁺ and Cl⁻ ions show an increasing trend as a function of increased pH values. The forest canopy in Shaoshan City has a strong effect on the uptake of SO₄ ²⁻ and NO₃ ⁻ ions under acid rain conditions. The decreasing order of ions leaching in the forest canopy is as follows: K⁺ > Ca²⁺ > Cl⁻ > Mg²⁺ > SO₄ ²⁻ > NO₃ ⁻ > NH₄ ⁺ > Na⁺. __________ Translated from Scientia Silvae Sinicae, 2007, 43(7): 1–4 [译自: 林业科学]     

Soil nitrogen status of larch plantations in comparison with secondary broad-leaved forest

IntroductionSoildegradationofsouthernChinesefir(CunnhaamialanceolaIe)pIantationshavebeenCon-tinuaIlyreiorted(ShenWeitongl992;Che11BingI1aol992;FangQil992).lnthenortI1eastforestregionsofChina,larch(LarirohensisandLa)`ixgInelinii)planta-tionsmade7opercentoftheman-madeforests,andthechangesinsoilpropertiesundertI1econiferouspIanta-tionshavealsodrawnmuchattentionofmanyforesters.OurobjectivewastoexaminethedifferenceinsoilnitrogenstatusbetweenLarchp1antatiol1sandsecon-darybroad-Ieavedforests(…     

异龄针阔混交林群落抑菌功能日变化的测定

选择秋季(9月中旬)典型晴朗天气,用自然沉降法采样,牛肉膏蛋白胨琼脂培养基培养,对校园的异龄针阔混交林群落抑菌作用进行日变化的测定,以探索混交林绿化模式的抑菌效果。结果表明,异龄针阔混交林群落能显著抑制空气中细菌含量,上午7:15~下午6:00,空气中菌落数量最大达1 400个/m3,抑菌效果达37%~78%。1d中抑菌有3个较明显的峰值,分别出现在10:00、12:00和15:00,抑菌率分别为51%,78%和64%,以12时抑菌率最高。     

辽东地区落叶松人工林连作对立地质量的影响

采用解析木导向曲线法编制了辽东地区日本落叶松地位指数表。在此基础上，对落叶松地拉指数与立地因子及落叶松栽植代数的关系进行了分析，认为不同栽植代数对落叶松人工森地位指数影响差异显，落叶松连作造成立地质量下降。     

THE WAY OF RESTORING AND REESTABLISHING BROADLEAVED/CONIFEROUS MIXED FOREST ECOSYSTEM FROM SECONDARY FOREST OF MONGOLIAN OAK

The necessity,basis,characteristic and methods of restoring and reestabling broadleaved/coniferous mixed forest ecosystem from the secondary forest of Mongolian oak(Quercus mongolica)are briefly set forth;then several effective methods of restoration and reestablishment are put forward and discussed as follows:openning up effect belt or island to establish horizontal order mixture;replenishing the blank niche to make vertical orderly mix-ture;planting artificial mixed forest to create biological diversity;developing ecological forestry,establishing integrated agroforestry ecosystem;and closing the land for forest and pre-serving some stands considering special conditions and demads.     

华北落叶松人工林林缘光照度研究

林内光照环境是林分更新的基础。本试验以华北落叶松人工林为研究对象,采用30m的样带法,比较了林分内部及林缘光照度的变化规律。结果表明:华北落叶松人工林林缘相对光照度随距林缘距离的增加而减小,之后趋于稳定;密度为630株/hm2时,随林缘距离的变化不太明显;林缘相对光照度与林分边缘不同距离呈明显的二次多项式关系;相对光照度能较好地反映林缘效应;随林分密度的增加林内光照度逐渐降低,相对光照度与密度呈显著幂函数关系。     

STUDY ON RETAINING FUNCTION OF LARCH PLANTATION

INTRoDUCTIONInterceptingandstoringrainwaterisamajorfunctionofforestwhichnotonlyde-creasestheintensityofprecipitation,theimpulsiveforceonthestandland,themnoffonthesoilsurface,butalsopro-longsthetimeofrunoffdecreasesthefloodpeak,andregulatesthelevelofrivers.DahurianlarchwithfastgrowthandextensiveadaptabilityisamajorspeciesofshelterbeltinNortheast,NorthandNorthwestareasofChina.Studiesonfunc-tionoflarchstandininterceptingandstor-ingrainwaterisveryimportanttoprotectheadwaterofriversandtoconse…     

Study on ecology ofFraxinus mandshurica

The reference and recent working results about ecology of ash (Fraxinus mandshurica) were reviewed, which including: distribution range, suitable site, phonology, growth, photosynthesis, productivity, natural regeneration effect and mixture effect. Synthesizing above, it was suggest that the ecological characters of ash such as distribution range, limited factors, growth site etc., as well as its biology characters, features in forest, should be considered as an important basis to develop this species by different regeneration ways such as natural regeneration, artificial regeneration and natural regeneration by man-help. And experiment in artificial regeneration showed that the mixture of ash with larch has benefit to being free from or alleviating frost injury and enhancing growth