Five new species of the Boletaceae from Japan

Five new species of the Boletaceae (Agaricales) from Japan are described and illustrated: (1) Boletus bannaensis sp. nov. (section Luridi), forming a grayish-brown pileus and rufescent flesh, found in subtropical evergreen broad-leaved forests; (2) Leccinum rhodoporosum sp. nov., forming discolorous red pores, a whitish stipe covered overall with violet-brown to blackish-brown furfuraceous scales and fusoid-cylindrical brown basidiospores, found in subtropical evergreen broad-leaved forests or warm-temperate Quercus-Pinus forests; (3) Pulveroboletus brunneoscabrosus sp. nov., forming a lemon-yellow pulverulent basidiomata covered overall with orange to brownish-orange appressed scales, found in subtropical to warm temperate evergreen broad-leaved forests; (4) Rubinoboletus monstrosus sp. nov., forming a brownish-orange to yellowish-brown pileus and a very short, nonreticulate, hollow stipe, found in subtropical evergreen broad-leaved forests; and (5) Tylopilus fuligineoviolaceus sp. nov., having a deep violet to blackish-brown pileus and brunnescent hymenophore, found in warm temperate Quercus-Castanopsis forests.     

亚热带常绿阔叶林和暖温带落叶阔叶林叶片热值比较研究

植物干重热值(GCV)是衡量植物生命活动及组成成分的重要指标之一,反映了植物光合作用中固定太阳辐射的能力。利用氧弹量热仪测定了亚热带和暖温带两个典型森林生态系统常见的276种常见植物叶片的干重热值,探讨了亚热带和暖温带植物热值分布特征,以及不同生活型、乔木类型间植物热值的变化规律。实验结果发现:亚热带常绿阔叶林和暖温带落叶阔叶林叶片热值的平均值分别为17.83 k J/g(n=191)和17.21k J/g(n=85),整体表现为亚热带植物暖温带植物。不同地带性植被的植物叶片热值在不同生活型间表现出相似的规律,其中亚热带常绿阔叶林表现为:乔木(19.09 k J/g)灌木(17.87 k J/g)草本(16.65 k J/g);暖温带落叶阔叶林表现为:乔木(18.41 k J/g)灌木(17.94 k J/g)草本(16.53 k J/g);不同乔木类型间均呈现常绿乔木落叶乔木、针叶乔木阔叶乔木的趋势。落叶阔叶乔木表现为亚热带暖温带,而常绿针叶乔木则呈现亚热带暖温带的趋势。此外,我们对于两个分布区域内的4种针叶树种叶片热值进行了比较,发现华北落叶松(19.32 k J/g,暖温带)杉木(19.40 k J/g,亚热带)马尾松(19.82 k J/g,亚热带)油松(20.95 k J/g,暖温带)。亚热带常绿阔叶林和暖温带落叶阔叶林植物热值的特征及其变化规律,为森林生态系统的能量流动提供了理论基础。     

Growth,morphology and leaf characteristics after simulated herbivory in Chinese subtropical evergreen saplings

Growth, morphology and leaf characteristics were assessed in late spring following simulated autumnal defoliation in second-year saplings of three Chinese subtropical evergreen tree species.Castanopsis fargesii showed strong compensatory growth in terms of plant biomass after removal of both 50 and 75% of leaf biomass and slight compensatory growth after 90% defoliation. DefoliatedC. fargesii saplings had more leaves per unit shoot length than non-defoliated saplings. New leaves on defoliated plants were smaller and had higher per area nitrogen content than new leaves on non-defoliated plants.Pinus massoniana andElaeocarpus japonicus showed strong and no compensatory growth, respectively, after 50% defoliation. The strong compensatory growth inP. massoniana andC. fargesii may partly explain why these species predominate in the early and late successional phases of evergreen broad-leaved forests     

南亚热带常绿阔叶林地上碳储量空间分布特征及其影响因素

旨在探讨南亚热带常绿阔叶林地上碳储量空间分布特征及其影响因素,为了解该区域森林的碳汇功能提供理论依据。通过对鼎湖山南亚热带常绿阔叶林20 hm²固定森林样地调查数据,采用一元线性回归分析和主成分分析方法,划分优势种和非优势种,研究地上碳储量的空间分布和生物/非生物因素的影响,获取了以下结果:(1)优势种对鼎湖山南亚热带常绿阔叶林地上碳储量贡献更大(1533.85 Mg,74.72%),尤其是大径级物种(1389.68 Mg,67.69%)。优势种地上碳储量(CV=0.635)的空间分布较非优势种(CV=0.690)更加均匀。(2)物种多样性与优势种和总体地上碳储量负相关,而与非优势种正相关。(3)群落总体、优势种和非优势种的地上碳储量均与结构多样性显著正相关。然而,结构多样性对非优势种地上碳储量的影响程度高于优势种。(4)群落中的土壤营养度、凹凸度与地上碳储量正相关。综上所述,通过提升非优势种的物种多样性可以增加鼎湖山南亚热带常绿阔叶林地上碳储量。此外,改善土壤营养条件也有助于提升南亚热带森林的碳汇功能。     

中国两个气候过渡区森林土壤线虫群落的比较研究

为比较不同气候过渡区地带性森林土壤线虫群落结构和多样性,以南亚热带向中亚热带气候过渡区的石门台常绿阔叶林和北亚热带向暖温带气候过渡区的鸡公山落叶阔叶林为样地,探讨不同气候区土壤微食物网能流方式的差异。结果表明,石门台土壤线虫群落属数(S)、生物量(Biomass)、多样性指数(H')、丰富度指数(SR)、成熟度指数(MI)和结构指数(SI)在表层土壤(0~10 cm)均显著高于鸡公山。石门台的土壤线虫通路指数(NCR)均值高于0.5,而鸡公山的NCR均值小于0.5,说明前者土壤食物网可能偏向于细菌能流通道,而后者偏向于真菌能流通道,这也与食细菌线虫、食真菌线虫生物量的计算结果一致。可见线虫群落结构确实存在明显的南北差异,并较好地指示了土壤能流和养分循环状况。     

亚热带常绿阔叶林和杉木人工林有机碳流失动态特征对降雨的响应

揭示亚热带森林土壤有机碳流失规律是制定相应措施以巩固和维持森林生态系统碳汇的关键。然而已有研究存在的监测对象单一、频率过低、时间过短等问题,导致对这一规律的认识仍然不足。选择亚热带典型的常绿阔叶林和杉木人工林为研究对象,每次降雨过后监测其径流量、泥沙量,分析径流和泥沙中的可溶性有机碳（Dissolved organic carbon,DOC）含量以及颗粒有机碳（Particle organic carbon,POC）含量。旨在比较两种森林DOC和POC流失量的差异,并分析二者与降雨量、降雨强度、5 min最大雨强和降雨侵蚀力四个降雨特征值的关联。拟验证以下两个问题：（1）杉木人工林的DOC和POC流失量是否高于常绿阔叶林;（2）降雨侵蚀力对DOC和POC的解释是否优于降雨量、降雨强度和5 min最大雨强。研究结果发现常绿阔叶林径流量、泥沙量、径流水中DOC浓度和POC浓度、DOC和POC流失量均显著高于杉木人工林。回归分析表明常绿阔叶林和杉木人工林DOC和POC流失量与降雨量、降雨强度和降雨侵蚀力呈显著的线性或幂函数相关,其中降雨量与DOC和POC流失量之间的拟合关系最优。常绿阔叶林产流和产沙量高于杉木人工林可能与前者的林下植被生物量较低有关,前者径流水中DOC浓度和POC浓度较高可归因于其较高的总生物量和土壤有机碳含量。在未来森林经营过程中应合理管理林下植被,尽量减少和避免林下植被的抚育伐,从而能够降低有机碳的水土流失,达到巩固和维持森林碳汇的目的。在未来气候变暖导致降水变化背景下,利用降雨量作为预测指标能够较好评估我国亚热带森林有机碳流失的风险。     

基于集成生物圈模型的南岭不同植被类型碳收支研究

广东南岭保存着世界上同纬度带上最完整的亚热带植被,森林资源丰富,具有巨大的固碳潜力。然而,目前该地区不同森林植被类型的碳收支年积累量特征及月动态规律尚不明确。选择广东南岭国家级自然保护区内沟谷常绿阔叶林、山地常绿阔叶林、针阔叶混交林和山顶常绿阔叶矮林4种典型森林植被为研究对象,运用集成生物圈模型(IBIS)对其2020年总初级生产力(GPP)、净初级生产力(NPP)、净生态系统生产力(NEP)和土壤异养呼吸(R_h)进行模拟,利用样地调查数据对NPP模拟结果进行验证,分析该地区不同植被类型的碳收支年积累量特征及月变化特征。研究结果表明,2020年南岭不同植被类型GPP、NPP、NEP和R_h的平均值分别为1.709、0.718、0.596和0.123 kg C m^-2 a^-1,4种植被类型中GPP最高的是沟谷常绿阔叶林,NPP、NEP最高的是山地常绿阔叶林,山顶常绿阔叶矮林的GPP、NPP和NEP均相对较低。南岭不同植被类型全年各月均表现出碳汇(NEP>0),逐月NPP和NEP均表现为双峰变化规律...     

中国4种典型森林中常见乔木叶片的非结构性碳水化合物研究

植物叶片的非结构性碳水化合物(non-structural carbohydrates,NSC)不仅为植物的代谢过程提供重要能量,还能一定程度上反映植物对外界环境的适应策略。以温带针阔混交林(长白山)、温带阔叶林(东灵山)、亚热带常绿阔叶林(神农架)和热带雨林(尖峰岭)4种森林类型的树种为研究对象,利用蒽酮比色法测定了163种常见乔木叶片可溶性糖、淀粉和NSC(可溶性糖+淀粉)含量,探讨了不同森林类型植物叶片NSC的差异及其地带性变化规律。结果显示：（1）从森林类型上看,植物叶片NSC含量从北到南递减,即温带针阔混交林(170.79 mg/g)>温带阔叶林(100.27 mg/g)>亚热带常绿阔叶林(91.24 mg/g)>热带雨林(80.13 mg/g)。（2）从生活型上看,无论是落叶树还是阔叶树,其叶片可溶性糖、淀粉和NSC含量均表现为：温带针阔混交林>温带阔叶林>亚热带常绿阔叶林>热带雨林;北方森林叶片可溶性糖、淀粉和NSC含量均表现为落叶树种>常绿树种,或阔叶树种>针叶树种。（3）森林植物叶片NSC含量、可溶性糖与淀粉含量比值与年均温和年均降水量均呈显著负相关。研究表明,森林植物叶片可溶性糖、淀粉和NSC含量以及可溶性糖与淀粉含量比值均具有明显的从北到南递减的地带性规律;其NSC含量以及可溶性糖与淀粉含量比值与温度和水分均呈显著负相关的变化规律可能是植物对外界环境适应的重要机制之一。该研究结果不仅为阐明中国主要森林树种碳代谢和生长适应对策提供了数据基础,而且为理解区域尺度森林植被对未来气候变化的响应机理提供新的视角。     

Ectomycorrhizae,arbuscular mycorrhizae,and dark-septate fungi on <Emphasis Type="Italic">Salix humboldtiana</Emphasis> in two riparian populations from central Argentina

Colonization of Salix humboldtiana (Salicaceae) by ectomycorrhizae (ECM), arbuscular mycorrhizae (AM), and dark-septate endophytic (DSE) fungi was studied throughout autumn on two riparian populations in central Argentina. AM and DSE infection on roots ranged from 0% to 17% and from 2% to 20% respectively, whereas ECM colonization was higher, varying between 33% and 99% for both sites. Seven ECM morphotypes were found on S. humboldtiana roots. The nuclear rDNA internal transcriber spacer (ITS) region from the ectomycorrhizal root tips was amplified using ITS-1F and ITS-4 primers. Two of the seven ECM types were identified by searching GenBank blasts: one attributed to the genus Tomentella (Thelephoraceae) and the second most closely matched to Inocybe sp. (Cortinariaceae). The ECM colonization varied among sampling dates and sites, whereas AM and DSE colonization varied only among sampling dates. Diversity values for the ECM morphotype were not significantly different for autumn months or among the two sites. Positive correlations were found between Inocybe sp. and sites and between Inocybe sp., Tomentella sp., morphotypes III, IV, and VI, and sampling dates. This article provides the first documented evidence of co-occurrence of ECM, AM, and DSE in S. humboldtiana.     

Fungal colonization and decomposition of Castanopsis sieboldii leaves in a subtropical forest

Fungi play a crucial role in the decomposition of lignin in fallen leaves but few studies have examined the functional roles of ligninolytic fungi associated with the decomposition of fallen leaves on tropical forest soils. This study examined fungal populations responsible for lignin decomposition in Castanopsis sieboldii leaves in a subtropical evergreen broad-leaved forest in southern Japan. Fallen leaves of C. sieboldii are characterized by the occurrence of bleached portions attributable to fungal colonization of leaf tissues and decomposition of lignin. The bleached area accounted for 29.7%, on average, of the total area of C. sieboldii fallen leaves in the study site. Leaf mass per unit area (LMA) and lignin content were lower in the bleached area than in the surrounding nonbleached area of the same leaves, indicating that removal of lignin enhanced mass loss from leaf tissues and created small-scale heterogeneity of decomposition within single leaves. An unidentified species of Lachnocladiaceae (Basidiomycetes) was isolated frequently from the bleached area and caused selective decomposition of lignin in leaves under pure culture conditions, indicating that this fungus was responsible for the bleaching. The greater hyphal length of basidiomycetes in the bleached area than in the nonbleached area supported the finding that this Lachnocladiaceae sp. was associated with the bleaching. The relatively rapid decomposition of C. sieboldii leaves on the subtropical forest soil is partly attributable to colonization of the litter by this Lachnocladiaceae sp.     

中国四种森林类型主要优势植物的C:N:P化学计量学特征

为了评价不同森林类型的生态化学计量特征的差异, 以吉林长白山温带针阔混交林、广东鼎湖山亚热带常绿阔叶林、云南西双版纳热带季雨林和江西千烟洲亚热带人工针叶林为研究对象, 通过对2007年4月-2008年5月4种典型区域森林植物叶片和凋落物的碳(C)氮(N)磷(P)元素质量比与N、P再吸收率的分析, 探讨了4种森林类型N、P养分限制和N、P养分再吸收的内在联系。结果表明: 1)从森林类型上看, 温带针阔混交林叶片的C : N : P为321 : 13 : 1, 亚热带常绿阔叶林叶片的C : N : P为561 : 22 : 1, 热带季雨林叶片的C : N : P为442 : 19 : 1, 亚热带人工针叶林叶片的C : N : P为728 : 18 : 1; 凋落物的C : N : P也是亚热带人工林最高, 达1 950 : 27 : 1, 温带针阔混交林的最低, 为552 : 14 : 1, 热带季雨林的为723 : 24 : 1, 亚热带常绿阔叶林的为1 305 : 35 : 1, 不同森林类型凋落物的C : N : P的计量大小关系与叶片的结果一致; 2)从植物生活型上看, 常绿针叶林叶片的C : N均显著高于常绿阔叶林及落叶阔叶林; 叶片C : P与森林类型的关系并不十分密切; 常绿阔叶林叶片的N : P最高, 常绿针叶林次之, 落叶阔叶林最低; 3)植物叶片的N : P与月平均气温有显著的负相关关系, 但叶片的C : P基本不受月平均气温影响, 叶片的C、N、P计量比与降水的线性关系不显著; 4)高纬度地区的植物更易受N元素限制, 而低纬度地区植物更易受P元素的限制; 但受N或P限制的植物并不一定具有高的N或P再吸收率。研究结果表明, 不同类型森林的叶片与凋落物的化学计量特征具有一致性, 但是环境因子对不同类型植物化学计量比的影响并不相同。     

Chloroplast diversity and population differentiation of Castanopsis fargesii (Fagaceae): a dominant tree species in evergreen broad-leaved forest of subtropical China

Subtropical forests in China constitute the major expanse of evergreen broad-leaved forest in East Asia. The significant genetic divergence of the keystone tree species should be expected due to the huge geomorphological and environmental changes from west to east in subtropical China. In this study, a total of 652 individuals from 27 populations of Castanopsis fargesii throughout its natural range in mainland China were genotyped with eight chloroplast microsatellite markers to investigate genetic diversity, population differentiation, and demographic history of C. fargesii. Phylogeographic structure among populations of C. fargesii was evidenced by the permutation test, revealing that N_ST was significantly higher than G_ST . The strong genetic differentiation found among populations was well in accordance with isolation-by-distance model. In addition, significant isolation by elevation was detected among populations. Significant genetic differentiations were revealed among the west, center, and east regions by approximate Bayesian computations (ABC). The genetic divergence might reflect the regional responses to the fast and dramatic uplift of Yunnan-Guizhou Plateau and Wuyi mountain range in the Pleistocene. In the present study, contraction-expansion process was detected in the west, center, and east regions, indicating that geomorphological remodeling together with climatic changes in the Pleistocene had strong impact on genetic structure of C. fargesii.     

南亚热带不同海拔常绿阔叶林树种叶性状的比较分析

南亚热带地带性植被是季风常绿阔叶林(海拔300～600 m;简称季风林),在中山地带则分布为山地常绿阔叶林(海拔1 000～1 500 m;简称山地林)。山地林的生态价值日益受到重视,但是对其树种的环境适应性仍缺乏足够了解。该研究基于南亚热带典型山地林(广西大明山)和季风林(广东鼎湖山)的固定样地,共测定57种代表性树种的叶形态解剖特征、机械强度和水力学性状,比较不同海拔常绿阔叶林树种叶性状以及多类性状关联性的差异。结果表明,与季风林树种相比,山地林树种叶较厚、比叶面积较小、机械强度较高,有利于提高对较高海拔山区冬季冰冻的适应能力。在2022年夏季持续高温干旱时期,季风林树种的叶水势和水力安全边界均低于山地林。但是大部分树种水力安全边界为正值且种间变异较大,表明不同海拔常绿阔叶林的水力风险较低。不同海拔常绿阔叶林的叶性状网络不同,山地林树种叶水力安全性和效率性无权衡关系,而季风林树种叶经济学性状(如比叶面积)与其他指标的关联性较弱。基于叶性状的研究揭示了南亚热带不同海拔常绿阔叶林树种适应策略的差异性和多样性。     

Resorption Efficiency of Four Cations in Different Tree Species in a Subtropical Common Garden

High rainfall in subtropical regions can leach cation elements from ecosystems, which may limit plant growth. Plants often develop efficient resorption patterns to recycle elements, but there is relatively little available information on this topic. In February 2012, a common garden was established in a subtropical forest by planting dominant trees from the area. Green and senescent leaves were sampled from 11 tree species. The concentrations of potassium (K), calcium (Ca), sodium (Na) and magnesium (Mg) were determined, and the resorption efficiencies were calculated. The results showed significant K, Na and Mg resorption in most of the investigated tree species, while Ca mainly displayed accumulation. Evergreen coniferous and evergreen broad-leaved trees (such as Cunninghamia lanceolata, Pinus massoniana, Cinnamomum camphora, and Michelia macclurei) exhibited relatively higher resorption efficiencies of K (39.0%–87.5%) and Na (18.3%–50.2%) than deciduous broad-leaved trees. Higher Mg resorption efficiencies (>50%) were detected in Liriodendron chinense, C. lanceolata and P. massoniana than in other trees. Overall, evergreen coniferous and evergreen broad-leaved trees could show higher cation resorption than deciduous broad-leaved trees. K and Mg resorption efficiencies and Ca accumulation decrease with increasing nutrient concentrations in green leaves. Our results emphasize that nutrient resorption patterns largely depend on elements and plant functions, which provides new insights into the nutrient use strategies of subtropical plants and a reference for the selection of suitable tree species in this region.     

Ectomycorrhiza communities of red oak (<Emphasis Type="BoldItalic">Quercus rubra</Emphasis> L.) of different age in the Lusatian lignite mining district,East Germany

Ectomycorrhizal (ECM) communities were assessed on a 720 m² plot along a chronosequence of red oak (Quercus rubra) stands on a forest reclamation site with disturbed soil in the lignite mining area of Lower Lusatia (Brandenburg, Germany). Adjacent to the mining area, a red oak reference stand with undisturbed soil was investigated reflecting mycorrhiza diversity of the intact landscape. Aboveground, sporocarp surveys were carried out during the fruiting season in a 2-week interval in the years 2002 and 2003. Belowground, ECM morphotypes were identified by comparing sequences of the internal transcribed spacer regions from nuclear rDNA with sequences from the GenBank database. Fifteen ECM fungal species were identified as sporocarps and 61 belowground as determined by morphological/anatomical and molecular analysis of their ectomycorrhizas. The number of ECM morphotypes increased with stand age along the chronosequence. However, the number of morphotypes was lower in stands with disturbed soil than with undisturbed soil. All stands showed site-specific ECM communities with low similarity between the chronosequence stands. The dominant ECM species in nearly all stands was Cenococcum geophilum, which reached an abundance approaching 80% in the 21-year-old chronosequence stand. Colonization rate of red oak was high (>95%) at all stands besides the youngest chronosequence stand where colonization rate was only 15%. This supports our idea that artificial inoculation with site-adapted mycorrhizal fungi would enhance colonization rate of red oak and thus plant growth and survival in the first years after outplanting.     

Post-fire, seasonal and annual dynamics of the ectomycorrhizal community in a Quercus ilex L. forest over a 3-year period

Two study plots, burned and control, were established in autumn 1998 in a Quercus ilex forest located in northern Spain, part of which had been affected by a low intensity fire in 1994. Soil samples for ectomycorrhizae (ECM) were taken over a 3-year period in each study plot in spring, summer, autumn and winter. ECM morphotypes were identified and the relative abundance of each morphotype in each soil sample calculated, along with species richness, Shannon diversity index and percentage of mycorrhization in each soil sample. The relative abundance of certain ECM morphotypes differed between burned and control plots, and the percentage of mycorrhizal tips was significantly lower in the burned than in the control plot. Nevertheless, there were no significant differences in the diversity, species richness or species composition of the ECM community in the burned and control plots. The dominant ECM morphotypes in both stands were Cenococcum geophilum and several thelephoroid fungi. Sphaerosporella brunnea and Pisolithus tinctorius thrived especially in the burned plot, whereas three ectomycorrhizal morphotypes assigned to the genus Hebeloma were especially abundant in the control plot. There was no significant variation in the relative abundance of the ECM morphotypes between seasons, but ECM community species richness was highest in autumn and lowest in summer. The percentage of mycorrhizal tips reached a maximum in winter, with its minimum in autumn. Collection of samples over the 3-year period also enabled us to detect a significant increase in percentage of ECM colonisation in the burned stand over time.     

鼎湖山森林群落的总生产力

本文根据鼎湖山季风常绿阔叶林和针阔叶混交林的垂直结构和成层现象,应用红外线CO_2气体分析等方法,分层测定了主要植物33种57株的光合速率,研究了两个群落的总初级生产力。结果表明:季风常绿阔叶林的总生产力(吨干物质·公顷~(-1),年~(-1))为146.695,针阔叶混交林为128.5597,前者比后者高,但后者叶面积指数适度,林内透光良好,树干生长粗壮,因而经济效益较高。     

深圳梧桐山风景区昆虫资源调查及群落结构分析

2012年7月-2013年7月,对深圳梧桐山风景区昆虫资源进行系统调查,并对其群落结构进行分析。期间共采集昆虫标本2934号,鉴定出166种,隶属17目98科。通过对不同生境昆虫物种丰富度和多样性指数统计分析得出,亚热带常绿阔叶林昆虫物种多样性指数最高,为3.29;南亚热带常绿灌丛昆虫多样性指数最低,为1.88。各种生境昆虫物种多样性指数从大到小排列为:亚热带常绿阔叶林南亚热带针阔叶混交林南亚热带人工常绿阔叶林南亚热带常绿灌丛。不同生境昆虫群落相似性系数在0.0889-0.2690之间,随着植被构成和环境小气候的差别越大相似性系数越小,说明梧桐山风景区各个生境之间昆虫群落具有一定的独立性。通过对不同垂直地带昆虫物种多样性指数统计分析得出,海拔介于300-600 m地带昆虫物种多样性指数最高,为3.30,海拔900 m以上地带昆虫多样性指数最低,为1.06。不同垂直地带昆虫多样性指数从大到小排列顺序为:海拔300-600 m海拔600-900 m海拔100-300 m海拔900 m以上。     

Shifts in plant nutrient use strategies under secondary forest succession

In evergreen broad-leaved forests (EBLFs) in Tiantong National Forest Park, Eastern China, we studied the soil chemistry and plant leaf nutrient concentration along a chronosequence of secondary forest succession. Soil total N, P and leaf N, P concentration of the most abundant plant species increased with forest succession. We further examined leaf lifespan, leaf nutrient characteristics and root–shoot attributes of Pinus massoniana Lamb, the early-successional species, Schima superba Gardn. et Champ, the mid-successional species, and Castanopsis fargesii Franch, the late-successional species. These species showed both intraspecific and interspecific variability along succession. Leaf N concentration of the three dominant species increased while N resorption tended to decrease with succession; leaf P and P resorption didn’t show a consistent trend along forest succession. Compared with the other two species, C. fargesii had the shortest leaf lifespan, largest decay rate and the highest taproot diameter to shoot base diameter ratio while P. massoniana had the highest root–shoot biomass ratio and taproot length to shoot height ratio. Overall, P. massoniana used ‘conservative consumption’ nutrient use strategy in the infertile soil conditions while C. fargesii took up nutrients in the way of ‘resource spending’ when nutrient supply increased. The attributes of S. superba were intermediate between the other two species, which may contribute to its coexistence with other species in a wide range of soil conditions.     

基于FORCCHN模型的中国典型森林生态系统碳通量模拟

森林生态系统是陆地碳循环的重要组成部分,其固碳能力显著高于其他陆地生态系统,研究森林生态系统碳通量是认识和理解全球变化对碳循环影响的关键。碳循环模型是研究森林生态系统碳通量有效工具。以长白山温带落叶阔叶林、千烟洲亚热带常绿针叶林、鼎湖山亚热带常绿阔叶林和西双版纳热带雨林等4种中国典型森林生态系统为研究对象,利用涡度相关2003-2012年观测数据,评估FORCCHN模型对生态系统呼吸（ER）,总初级生产力（GPP）,净生态系统生产力（NEP）的模型效果。结果表明：（1） FORCCHN模型能够较好的模拟中国4种典型森林生态系统不同时间尺度的碳通量。落叶阔叶林和常绿针叶林ER和GPP的逐日变化模拟效果较好（ER的相关系数分别为0.94和0.92,GPP的相关系数分别为0.86和0.74）;（2）4种森林生态系统碳通量季节动态模拟值和观测值显著相关（P<0.01）,ER、GPP、NEP的观测值和模拟值的R²分别为0.77-0.93、0.54-0.88和0.15-0.38;模型可以很好地模拟森林生态系统不同季节碳汇（NEP>0）,碳源（NEP<0）的变化规律;（3）4种森林生态系统碳通量模拟值与观测值的年际变化有很好的吻合度,但在数值大小上存在差异,模型高估了常绿阔叶林的ER和GPP,略微低估了其他3种森林生态系统ER和GPP。