施肥对日本落叶松人工林细根生物量的影响

以辽宁东部山区16年生日本落叶松人工林为研究对象,探讨施肥对落叶松细根总生物量、不同层次生物量及不同根序生物量的影响.结果表明,与对照相比,施氮肥显著降低细根总生物量(P<0.01),而施磷肥及施氮+磷肥处理的细根总生物量差异不显著(P>0.05).落叶松人工林表层土壤(0～10 cm)细根生物量明显高于亚表层(10～20 cm)(P<0.01),各处理样地表层生物量占总生物量的64％～73％.施肥对不同层次、不同级别根序细根生物量的影响不同.与对照相比,施氮肥显著地降低了表层土壤1、3、4、5级根生物量(P<0.05),施磷肥(5级根除外)、施氮+磷肥(2级根除外)表层土壤各级根序细根生物量降低均不显著(P>0.05).在亚表层土壤,施氮肥和磷肥对各级根序生物量均没有显著影响(P>0.05);施氮+磷肥显著增加了1级根生物量(P<0.05),而其余各级根序细根生物量差异不显著(P>0.05).     

植物粗提物对褐稻虱成虫取食的影响

分别用31科47种非嗜食植物乙醇提取物处理的稻株饲养褐稻虱Nilaparvata lugensStal成虫,研究对褐稻虱成虫的拒取食作用。结果表明,大多数供试植物提取物对褐稻虱有一定程度的拒取食效果。大蒜、苦楝油、白花非洲山毛豆的提取物对褐稻虱成虫拒食效果最好,24h后的拒取食率分别达89.19%、75.63%与63.74%。薇甘菊、蟛蜞菊、荚竹桃、含羞草、鱼尾葵、艾蒿、人心果和走马箭8种植物提取物拒取食率均达50%以上。相反,莎草、鸡矢藤、甘草、飞机草、地肤、水葫芦、华南毛蕨、假连翘、鼬瓣草、尾叶桉和白花丹11种植物提取物对褐稻虱成虫取食具有一定的刺激作用。     

植物挥发性物质对落叶松球果花蝇的驱避效果

为研究外源植物挥发性物质对落叶松球果花蝇（Strobilomyia spp.）对寄主定位的干扰作用,在哈尔滨市和大兴安岭加格达奇兴安落叶松（Larix gmelinii）种子园,用松节油、樟脑、丁香油进行了室内生测和林间喷施试验。在室内,球果花蝇对1％松节油的反应率为94.23％,与1％丁香油、3％松节油、20％丁香油相比差异显著;对1％樟脑的反应率为87.92％。球果花蝇对2％丁香油的反应率最低,仅为16.30％。在室内及林间,1％松节油及1％樟脑对球果花蝇都表现为驱避作用。1％松节油及其对照对球果花蝇的驱避效果最好,平均每果虫数较清水对照的3.51分别降低了2.85和2.66,使球果被害率降低了57.0％和46.2％,种子被害率分别降低了24.7％和27.7％。其次是1％脑及其对照,每果虫数较清水对照降低了1.83和1.44个,球果被害率分别降低了9.0％和30.7％,种子被害率分别下降了12.2％和26.9％。1％丁香油对花蝇在室内表现为诱引作用,在林间表现为驱避作用。在喷施3种挥发性物质及其对照后,各个处理的球果挥发性物质主要组分的总量都较清水对照增加,各处理的α-蒎烯相对含量较清水对照大幅度降低,降低幅度在13.56％-24.83％之间;各处理的β-罗勒烯都有不同程度的增加。β-蒎烯、3-蒈烯、月桂烯、水芹烯的相对含量在各处理中升降不一。     

施肥对日本落叶松不同根序细根养分浓度的影响

以辽宁东部山区16年生日本落叶松人工林为对象,探讨施肥对落叶松1～5级不同根序等级细根养分浓度的变化.结果表明：不同根序等级细根全碳浓度差异不显著,施肥对各级根序全碳浓度没有显著影响;在前5级根序中,1级根非结构性碳水化合物（TNC）浓度最低,N和P浓度最高;而5级根TNC浓度最高,N和P浓度最低.TNC浓度随着根序增加而升高,N和P浓度则相应下降.施肥仅对1级根组织中N和P浓度有显著影响;不同根序根组织中C/N/P具有明显差异,1级根平均C/N/P为423∶16∶1,5级根为726∶16∶1,随着根序增加,C在3种元素中的比例显著增加,而N的比例变化不大.施N肥并没有改变C的比例;但施P肥或施N+P肥均降低了前3级根（0～10 cm）或前2级根（10～20 cm）C和N在3种元素中的比例.     

施肥对日本落叶松不同根序细根养分浓度的影响

以辽宁东部山区16年生日本落叶松人工林为对象,探讨施肥对落叶松1～5级不同根序等级细根养分浓度的变化.结果表明：不同根序等级细根全碳浓度差异不显著,施肥对各级根序全碳浓度没有显著影响;在前5级根序中,1级根非结构性碳水化合物（TNC）浓度最低,N和P浓度最高;而5级根TNC浓度最高,N和P浓度最低.TNC浓度随着根序增加而升高,N和P浓度则相应下降.施肥仅对1级根组织中N和P浓度有显著影响;不同根序根组织中C/N/P具有明显差异,1级根平均C/N/P为423∶16∶1,5级根为726∶16∶1,随着根序增加,C在3种元素中的比例显著增加,而N的比例变化不大.施N肥并没有改变C的比例;但施P肥或施N+P肥均降低了前3级根（0～10 cm）或前2级根（10～20 cm）C和N在3种元素中的比例.     

落叶松和水曲柳人工林细根生长、死亡和周转

 细根周转是陆地生态系统碳分配格局与过程的核心环节,而细根周转估计的关键是了解细根的生长和死亡动态。该研究以18年生落叶松(Larix gmelinii)和水曲柳(Fraxi nus mandshurica)人工林为对象,采用微根管（Minirhizotron）技术对两树种0～40 cm深度的细根生长和死亡动态进行了为期1年的观测,研究了两树种细根在不同土层深度的生长与死亡动态、细根周转以及与土壤有效氮含量、土壤温度、大气温度和降水的关系。结果表明：1） 落叶松平均细根生长（Root length density production, RLDP）0.0045 mm•cm^－2•d^－1）明显低于水曲柳RLDP（0.0077 mm•cm^－2•d^－1）。两个树种细根平均RLDP在表层（0～10 cm）最大,而底层（30～40 cm）最小 ,两树种平均细根死亡（Root length density mortality, RLDM）也表现同样规律 。水曲柳春季生长的细根占41.7%,夏季占39.7%,而落叶松细根生长分别是24.0%和51.2%,水曲柳细根死亡主要发生在春季（34.3%） 和夏季（34.0%）,而落叶松细根死亡主要发生在夏季和秋季（分别占28.5%和32.3%）,两 树种细根生长与死亡在冬季均较小;2）落叶松细根年生长量（0.94 mm•cm^－2•a^－1）和年死亡量（0.72 mm•cm^－2•a^－1）明显低于水曲柳（1.52和1.21 mm•cm^－2•a^－1）,两树种细根表层年生长量和年死亡量均最高,底层最低。落叶松细根年周转为3.1次•a^－1（按年生长量计算）和2.4次•a^－1（按年死亡量计算）,相比较,水曲柳细根年周转分别为2.7次•a^－1和2.2次•a^－1;3）土壤有效氮含量、土壤温度、大气温度和降水综合作用影响细根生长和死亡动态,可以解释细根生长80%的变异和细根死亡95%以上的变异。     

十九种植物精油对茶丽纹象甲成虫的驱避和拒食活性

为了寻找茶丽纹象甲Myllocerinus aurolineatus Voss无公害防治新途径,采用行为生测法测定了19种植物精油对茶丽纹象甲的驱避和拒食活性。结果表明:大蒜油allitridi、芸香(Cantleyt corniculata(Becc)Howard)油、丹参(Salvia miltiorrhiza Bunge.)、穿心莲(Andrographis paniculata(Burm.f.)Nees)、艾叶(Artemisia argyi Levl.et Vant.)、薰衣草(Lavender angustifolia Mill.)、何首乌(Fallopia multiflora(Thunb.)Harald.)、苦参(Sophora flavescens Alt.)、黄岑(Scutellaria baicalensis Georgi)、益母草(Leonurus heterophyllus Sweet)和金银花(Lonicera Japonica Thunb.)提取物对象甲的雄性和(或)雌性具有驱避活性。其中,大蒜油、丹参、何首乌和苦参又分别对象甲的雌性或雄性具有显著的选择性拒食活性;与对照相比,芸香油和金银花提取物对象甲具有非选择性拒食活性,而大蒜油和益母草提取物会显著提高象甲的取食量。艾叶、薰衣草和黄岑提取物对象甲仅表现出一定的驱避活性,未表现出拒食活性。与对照相比,穿心莲提取物对象甲具有显著的引诱作用。本研究证明芸香油、丹参、何首乌、苦参和金银花5种物质对象甲具有多方面的作用活性,具有很好的研究价值和实践意义。     

亚洲玉米螟幼虫拒食活性的一种新生测方法

在研究植物源次生物质对亚洲玉米螟五龄幼虫的拒食活性中,按照改变的人工饲料配方制成饲料柱,发展出一种对饲料被取食的量直接计重的新生测方法。同时也报道了川楝素,紫雪花素和10个新克罗烷二萜化合物的活性测定结果。     

黄土高原白羊草、沙棘和辽东栎细根比根长特性

以黄土高原地区典型草本（白羊草）、灌木（沙棘）和乔木（辽东栎）为对象,研究了3种植物细根比根长在不同土层的分布状况以及与其它细根参数和土壤物理因子之间的相关性。结果表明,3种植物细根比根长的变化范围为6～55ram／rag。在0,80cm土层,白羊草、沙棘和辽东栎细根比根长变化范围分别为18—55mm／mg,14—4JDmm／mg,6—33mm／mg。3种植物0--80cm土层平均细根比根长从大到小依次为白羊草〉沙棘〉辽东栎。3种植物0-10cm土层细根比根长依次为沙棘〉辽东栎〉白羊草,10-80cm依次为白羊草〉辽东栎〉沙棘,表明3种植物细根比根长不仅在这两土层中的分布不具一致性,而且与0-80cm土层平均比根长也不具有一致性,进一步说明3种植物沿土壤剖面的生物量分配策略不同。相关分析表明,3种植物细根比根长与其它细根参数之间的相互关系各不相同,制约程度存在差异。与土壤物理因子的相关分析表明,3种植物细根比根长均随土壤含水量的增加而减少。土壤各级水稳性团聚体和土壤颗粒对3种植物细根比根长并无一致的影响。     

水曲柳和兴安落叶松人工林细根分解研究

  细根分解是陆地生态系统C和养分循环的重要环节。以往的细根分解研究以埋袋法的应用为主。然而, 由于埋袋法对分解材料的干扰以及对分解环境的改变使其很难揭示原位环境下根系的自然分解过程。该研究应用微根管(Minirhizotron)技术连续3年对水曲柳(Fraxinus mandshurica)和兴安落叶松(Larix gmelinii)细根的分解过程进行原位监测, 运用Kaplan–Meier方法估算细根分解的保存率及分解期中位值(即50%细根完全分解的时间, Median root decomposition time), 做分解曲线, 用对数秩检验(Log-rank test)方法分析不同树种、直径、根序及土层对细根保存率的影响。结果表明, 伴随时间延长, 细根的保存率逐渐下降, 兴安落叶松细根保存率的下降显著快于水曲柳(p<0.001), 两树种分解期中位值分别为(82±7) d 和(317±28) d; 不同直径等级(≤0.3、0.3～0.6、＞0.6 mm)细根的分解速率不同, 两树种最长分解期中位值均出现在最细直径(≤0.3 mm)根中; 高级根分解速率显著低于一级根(p<0.05); 土壤上层分解速度快, 随着土壤深度增加细根分解速率减小。微根管技术为了解细根自然分解过程提供了有效途径。     

Seasonal dynamics of fine root biomass,root length density,specific root length,and soil resource availability in a Larix gmelinii plantation

Fine root tumover is a major pathway for carbon and nutrient cycling in terrestrial ecosystems and is most likely sensitive to many global change factors.Despite the importance of fine root turnover in plant C allocation and nutrient cycling dynamics and the tremendous research efforts in the past,our understanding of it remains limited.This is because the dynamics processes associated with soil resources availability are still poorly understood.Soil moisture,temperature,and available nitrogen are the most important soil characteristics that impact fine root growth and mortality at both the individual root branch and at the ecosystem level.In temperate forest ecosystems,seasonal changes of soil resource availability will alter the pattern of carbon allocation to belowground.Therefore,fine root biomass,root length density(RLD)and specific root length(SRL)vary during the growing season.Studying seasonal changes of fine root biomass,RLD,and SRL associated with soil resource availability will help us understand the mechanistic controls of carbon to fine root longevity and turnover.The objective of this study was to understand whether seasonal variations of fine root biomass,RLD and SRL were associated with soil resource availability,such as moisture,temperature,and nitrogen,and to understand how these soil components impact fine root dynamics in Larix gmelinii plantation.We used a soil coring method to obtain fine root samples(≤2 mm in diameter)every month from Mav to October in 2002 from a 17-year-old L.gmelinii plantation in Maoershan Experiment Station,Northeast Forestry University,China.Seventy-two soil cores(inside diameter 60 mm;depth intervals:0-10 cm,10-20 cm,20-30 cm)were sampled randomly from three replicates 25 m×30 m plots to estimate fine root biomass(live and dead),and calculate RLD and SRL.Soil moisture,temperature,and nitrogen(ammonia and nitrates)at three depth intervals were also analyzed in these plots.Results showed that the average standing fine root biomass(live (32.2 g.m-2.a-1)in the middle(10-20 cm)and deep layer (20-30cm),respectively.Live and dead fine root biomass was the highest from May to July and in September,but lower in August and October.The live fine root biomass decreased and dead biomass increased during the growing soil layer.RLD and SRL in May were the highestthe other months,and RLD was the lowest in Septemberdynamics of fine root biomass,RLD,and SRL showed a close relationship with changes in soil moisture,temperature,and nitrogen availability.To a lesser extent,the temperature could be determined by regression analysis.Fine roots in the upper soil layer have a function of absorbing moisture and nutrients,while the main function of deeper soil may be moisture uptake rather than nutrient acquisition.Therefore,carbon allocation to roots in the upper soil layer and deeper soil layer was different.Multiple regression analysis showed that variation in soil resource availability could explain 71-73% of the seasonal variation of RLD and SRL and 58% of the variation in fine root biomass.These results suggested a greater metabolic activity of fine roots living in soil with higher resource availability,which resulted in an increased allocation of carbohydrate to these roots,but a lower allocation of carbohydrate to those in soil with lower resource availability.     

氮肥对水曲柳和落叶松细根寿命的影响

采用微根管技术研究了氮肥对水曲柳和落叶松细根生长、衰老和死亡的影响,探讨两树种细根寿命与氮有效性之间的相关关系.结果表明：林地施氮肥后,两树种细根数量都呈减少趋势,细根总体直径增加,分枝程度降低;氮肥使水曲柳细根存活率提高,细根中位值寿命延长105 d,而落叶松细根存活率对氮肥反应不敏感;施氮肥对细根寿命的延长效应主要体现在直径较小的一级根、表层（0～15 cm)根系和春夏季新生的细根,表明氮肥对高生理活性的细根
影响较强.     

施用氮肥对落叶松人工林一级根外生菌根侵染及形态的影响

以落叶松人工林为研究对象,通过施N肥试验,对不同季节、不同土壤深度根系进行取样,研究了1级根外生菌根真菌侵染率和形态,及其与不同季节、土壤深度和土壤N有效性的关系.结果表明:外生菌根真菌对落叶松人工林1级根的侵染率显著受不同季节和土壤深度土壤N有效性的影响.在不同季节和土层之间,施N肥导致菌根真菌侵染率下降.与未侵染菌根真菌相比,菌根真菌侵染导致1级根形态发生明显改变,平均直径增加18.7%,平均根长缩短23.7%,比根长降低16.3%.这种根系形态变化在不同季节、不同土壤深度处理中表现明显.菌根真菌侵染改变了1级根形态,影响根系的生理生态过程.     

2004—2008年落叶松人工林细根生产和死亡的季节动态

2004—2008年,采用微根管(minirhizotron)技术,对落叶松人工林细根生产和死亡进行连续动态观测,同时测定了温度(大气温度和土壤10 cm温度)和水分(降雨量和土壤10 cm深处含水量)的变化,研究细根生产、死亡的动态及其与温度和水分的关系.结果表明：落叶松细根年根长生产量在0.20～0.78 mm·cm^-2,死亡量在0.26～0.72 mm·cm^-2;2004—2006年细根年根长平均生产量(0.67 mm·cm^-2)和死亡量(0.59 mm·cm^-2)均高于2007—2008年细根年根长平均生产量和死亡量(0.37和0.39 mm·cm^-2);在生长季内（5—10月）,落叶松春末至夏季(6—7月) 的细根生产量占全年产量的51%～68%,秋末(10月)仅占全年的1%～4%;而夏末(8月)和秋季(9—10月)细根死亡量占全年的59%～70%,早春(5月)占全年的1%～5%.相关分析表明,大气温度变化可以解释细根生产量66%的变异,而土壤10 cm深处温度解释24%,降雨量解释27%.细根的死亡量与土壤10 cm深处温度呈指数正相关.     

Seasonal dynamics of fine root biomass, root length density, specific root length, and soil resource availability in a Larix gmelinii plantation

Fine root turnover is a major pathway for carbon and nutrient cycling in terrestrial ecosystems and is most likely sensitive to many global change factors. Despite the importance of fine root turnover in plant C allocation and nutrient cycling dynamics and the tremendous research efforts in the past, our understanding of it remains limited. This is because the dynamics processes associated with soil resources availability are still poorly understood. Soil moisture, temperature, and available nitrogen are the most important soil characteristics that impact fine root growth and mortality at both the individual root branch and at the ecosystem level. In temperate forest ecosystems, seasonal changes of soil resource availability will alter the pattern of carbon allocation to belowground. Therefore, fine root biomass, root length density (RLD) and specific root length (SRL) vary during the growing season. Studying seasonal changes of fine root biomass, RLD, and SRL associated with soil resource availability will help us understand the mechanistic controls of carbon to fine root longevity and turnover. The objective of this study was to understand whether seasonal variations of fine root biomass, RLD and SRL were associated with soil resource availability, such as moisture, temperature, and nitrogen, and to understand how these soil components impact fine root dynamics in Larix gmelinii plantation. We used a soil coring method to obtain fine root samples (⩽2 mm in diameter) every month from May to October in 2002 from a 17-year-old L. gmelinii plantation in Maoershan Experiment Station, Northeast Forestry University, China. Seventy-two soil cores (inside diameter 60 mm; depth intervals: 0–10 cm, 10–20 cm, 20–30 cm) were sampled randomly from three replicates 25 m × 30 m plots to estimate fine root biomass (live and dead), and calculate RLD and SRL. Soil moisture, temperature, and nitrogen (ammonia and nitrates) at three depth intervals were also analyzed in these plots. Results showed that the average standing fine root biomass (live and dead) was 189.1 g·m⁻²·a⁻¹, 50% (95.4 g·m⁻²·a⁻¹) in the surface soil layer (0–10 cm), 33% (61.5 g·m⁻²·a⁻¹), 17% (32.2 g·m⁻²·a⁻¹) in the middle (10–20 cm) and deep layer (20–30cm), respectively. Live and dead fine root biomass was the highest from May to July and in September, but lower in August and October. The live fine root biomass decreased and dead biomass increased during the growing season. Mean RLD (7,411.56 m·m⁻³·a⁻¹) and SRL (10.83 m·g⁻¹·a⁻¹) in the surface layer were higher than RLD (1 474.68 m·m⁻³·a⁻¹) and SRL (8.56 m·g⁻¹·a⁻¹) in the deep soil layer. RLD and SRL in May were the highest (10 621.45 m·m⁻³ and 14.83m·g⁻¹) compared with those in the other months, and RLD was the lowest in September (2 198.20 m·m⁻³) and SRL in October (3.77 m·g⁻¹). Seasonal dynamics of fine root biomass, RLD, and SRL showed a close relationship with changes in soil moisture, temperature, and nitrogen availability. To a lesser extent, the temperature could be determined by regression analysis. Fine roots in the upper soil layer have a function of absorbing moisture and nutrients, while the main function of deeper soil may be moisture uptake rather than nutrient acquisition. Therefore, carbon allocation to roots in the upper soil layer and deeper soil layer was different. Multiple regression analysis showed that variation in soil resource availability could explain 71–73% of the seasonal variation of RLD and SRL and 58% of the variation in fine root biomass. These results suggested a greater metabolic activity of fine roots living in soil with higher resource availability, which resulted in an increased allocation of carbohydrate to these roots, but a lower allocation of carbohydrate to those in soil with lower resource availability. __________ Translated from Acta Phytoecologica Sinica, 2005, 29(3): 403–410 [译自: 植物生态学报, 2005, 29(3): 403–410]     

关帝山华北落叶松人工林细根生物量空间分布及季节变化

利用根钻法研究了山西关帝山华北落叶松（Larix principis—rupprechtii Mayr）人工林细根生物量的空间分布和季节变化特征。结果表明,华北落叶松不同径级细根生物量随土层深度的增加而逐渐减少,土壤表层（0—10cm）中各径级细根的生物量最高,Ⅰ级细根（根直径0～1mm）的生物量在不同土层深度间差异显著（P〈0．05）;距树干不同水平距离处各径级的细根生物量差异均未达到显著水平（P〉0．05）。在0～10cm土层中,各径级细根生物量的季节变化差异显著（P〈0．05）,均表现为单峰型,峰值出现在9月份;在10～20cm和20-30cm土层中,Ⅰ级和Ⅱ级（根直径1～2mm）细根生物量季节变化差异显著,Ⅲ级细根（根直径2～5mm）和Ⅰ级死根（根直径0～2mm）生物量季节变化差异不显著。     

去叶对水曲柳和落叶松苗木当年生长及细根动态的影响

叶片被取食会导致树木生长发育和生理代谢发生显著的变化。目前对细根动态如何对叶片损失做出响应的了解仍然有限。以生物量分配和高生长策略不同的水曲柳(Fraxinus mandschurica)和落叶松(Larix gmelinii)苗木为研究对象, 进行了不同强度的人为去叶处理(叶面积去除0% (对照)、40%和80%), 采用微根管技术对细根(直径≤2 mm)生产和死亡的季节动态进行了定量观测, 同期测定了地上部分(苗高和地径)的生长。结果表明: 1)去叶降低了两树种苗高(统计上均不显著)和地径的生长, 但是对苗高生长的影响小于地径。随着去叶强度的提高, 苗木地上生长受到的影响加大, 生长季末期水曲柳苗高比对照降低3.3%-12.1%, 地径降低5.7%-23.1%; 而落叶松苗高和地径降低相对较少(< 12%)。2)去叶显著地减少了水曲柳和落叶松细根现存量(p< 0.001), 其相对增长量((去叶后现存量高峰-去叶当日现存量)/去叶当日现存量)随着去叶强度的加大而降低。3)与对照相比, 去叶后两树种细根生产量显著减少(p< 0.05), 而细根死亡量在不同处理间没有显著差异。综合来看, 去叶对水曲柳地上部分(特别是地径)生长影响较大, 而对落叶松地下部分(主要是新根)生长影响较大。研究结果为理解冠层碳供应对根系动态影响的种间差异及其机制提供了必要的理论依据。     

Estimation of fine root production, mortality and turnover with Minirhizotron in Larix gmelinii and Fraxinus mandshurica plantations

Fine root turnover is a major pathway for car-bon and nutrient cycling in forest ecosystems. However, to estimate fine root turnover, it is important to first understand the fine root dynamic processes associated with soil resource availability and climate factors. The objectives of this study were: (1) to examine patterns of fine root production and mortality in different seasons and soil depths in the Larix gmelinii and Fraxinus man-dshurica plantations, (2) to analyze the correlation of fine root production and mortality with environmental factors such as air temperature, precipitation, soil temperature and available nitrogen, and (3) to estimate fine root turn-over. We installed 36 Minirhizotron tubes in six mono-specific plots of each species in September 2003 in the Mao'ershan Experimental Forest Station. Minirhizotron sampling was conducted every two weeks from April 2004 to April 2005. We calculated the average fine root length, annual fine root length production and mortality using image data of Minirhizotrons, and estimated fine root turnover using three approaches. Results show that the average growth rate and mortality rate in L. melinii were markedly smaller than in F. mandshurica, and were high-est in the surface soil and lowest at the bottom among all the four soil layers. The annual fine root production and mortality in F. mandshurica were significantly higher than in L. gmelinii. The fine root production in spring and summer accounted for 41.7% and 39.7% of the total annual production in F. mandshurica and 24.0% and 51.2% in L. gmelinii. The majority of fine root mortality occurred in spring and summer for F. mandshurica and in summer and autumn for L. gmelinii. The turnover rate was 3.1 a-1 for L. gmelinii and 2.7 a-1 for F. mandshurica. Multiple regression analysis indicates that climate and soil resource factors together could explain 80% of the varia-tions of the fine root seasonal growth and 95% of the seasonal mortality. In conclusion, fine root production and mortality in L. gmelinii and F. mandshurica have dif-ferent patterns in different seasons and at different soil depths. Air temperature, precipitation, soil temperature and soil available nitrogen integratively control the dynamics of fine root production, mortality and turnover in both species.