NET PRODUCTIVITY AND TURNOVER RATE OF FINE ROOTS IN MIXED FOREST OF CUNNINGHAMIA LANCEOLATA AND TSOONGIODENDRON ODORUM

本文系统地研究了 2 7a生杉木观光木混交林和杉木纯林群落细根 (<2mm)的生物量、净生产力和年周转率。结果表明 ,混交林和纯林群落活细根现存量分别为 3 872和 3 315t·hm- 2 ,活细根现存量变化呈双峰型 ,在 3月和 9月出现两次高峰 ;死细根现存量为 1 5 0 9和 1 2 6 9t·hm- 2 ,数量变化呈现单谷型 ,在 5月或 3月出现最低值 ;细根净生产力分别为 4 12 4和 3 5 2 8t·hm- 2 a- 1 ,分别占各自群落净第一性生产力的 2 2 9%和2 0 9% ;细根年死亡量分别为 2 119和 1 894t·hm- 2 ,相当于各自群落地上部分凋落物量的 31 4%和 2 7 8% ;细根周转率分别为 1 0 7和 1 0 6 ,观光木、混交林杉木、纯林杉木的细根周转速率依次降低 ,而林下植被层细根周转率高于乔木层。表明细根周转是群落有机质归还的重要途径 ,对维持和改良地力有重要作用Studies on biomass, net productivity and annual turnover rate of fine roots in mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum and in pure stand of Cunninghamia lanceolata at 27 years old were carried out. The existing amount of living fine roots in both stands were up to 3 872 and 3 315?t·hm -2 , and their seasonal changes showed two peaks in March and September, and those of dead fine roots amounted to 1 509 and 1 269?t·hm -2 , being lowest in May or March. The net productivity of fine roots in both stands totaled to 4 124 and 3 528?t·hm -2 a -1 , accounted for 22 9% and 20 9% of total net primary productivity of community, respectively. In both stands, annual mortality of fine roots were 2 119 and 1 894?t·hm -2 , respectively, amounted 31 4% and 27 8% of annual aboveground litterfall. Annual turnover rate of fine roots was 1 07 in mixed stand and 1 06 in pure stand, which decreased successively from Tsoongiodendron odorum, Cunninghamia lanceolata in mixed forest to the pure stand, and that of undergrowth were higher than that of tree stralum in both stands. It was concluded that annual turnover of fine roots was an important way for organic matter in communities returning to forest floor.中国博士后科研基金;; 福建省科委重大基础研究项目 ( 2 0 0 0 -F -0 0 4);; 高等学校骨干教师资助计划资

Nutrient dynamics of decomposing leaf litter in natural and monoculture plantation forests of Castanopsis kawakamii in subtropical China

通过对中亚热带格氏栲天然林 (natural forest of Castanopsis kawakamii,约 15 0 a)、格氏栲和杉木人工林 (monocultureplantations of C.kawakamii and Cunninghamia lanceolata,33年生 )凋落叶分解过程中养分动态的研究表明 ,各凋落叶分解过程中 N初始浓度均发生不同程度的增加后下降 ;除格氏栲天然林中其它树种叶和杉木叶 P浓度先增加后下降外 ,其它均随分解过程而下降 ;除杉木叶外 ,其它类型凋落叶的 Ca和 Mg浓度呈上升趋势 ;凋落叶 K浓度均随分解过程不断下降。养分残留率与分解时间之间存在着指数函数关系 xt=x0 e- kt。凋落叶分解过程中各养分释放常数分别为 :N (k N) 0 .6 78～ 4 .0 88;P (k P)0 .6 2 1～ 4 .30 8;K(k K) 1.4 0 8～ 4 .4 2 1;Ca (k Ca) 0 .799～ 3.75 6 ;Mg (k Mg) 0 .837～ 3.894。除杉木叶外 ,其它凋落叶分解过程中均呈 k K>k P>k N>k Mg>k Ca的顺序变化。各林分凋落叶的年养分释放量分别为 N10 .73～ 4 8.19kg/ (hm2 · a) ,P0 .6 1～ 3.70kg/ (hm2· a) ,K6 .6 6～ 39.6 1kg/ (hm2· a) ,Ca17.90～ 2 0 .91kg/ (hm2· a) ,Mg3.2 1～ 9.85 kg/ (hm2· a)。与针叶树人工林相比 ,天然阔叶林凋落叶分解过程中较快的养分释放和较高的养分释放量有利于促进养分再循环 ,这对地力?Nutrient dynamics of decomposing leaf litter was studied in two 33-year-old plantations, Chinese fir (Cunninghamia lanceolata, CF) and Castanopsis kawakamii (CK), and compared with that of an adjacent natural forest of Castanopsis kawakamii (NF, ~150 year old) in Sanming, Fujian, China. During the decomposition, varying degree of initial increase followed by decrease of N concentrations was observed in leaf litter, while initial increase and then decrease of P concentration was only found in leaves of other tree species in the NF and Chinese fir needle. The concentrations of Ca and Mg increased in all leaves except for Chinese fir needle, whereas that of K decreased consistently. Using the model x_t=x_0e~(-kt), the decay constants of nutrients ranged from 0.678 to 4.088 for N (k_N), from 0.621 to 4.308 for P (k_P), from 1.408 to 4.421 for K (k_K), from 0.799 to 3.756 for Ca (k_(Ca)) and from 0.837 to 3.894 for Mg (k_(Mg)) respectively. The decay constants of nutrients during leaf-litter decomposition can be arranged in the sequence of k_K>k_P>k_N>k_(Mg)>k_(Ca), except for leaf litter of Chinese fir where k_K>k_(Mg)>k_(Ca)>k_N>k_P. Annual nutrient release from decaying leaf litters in the three forests was N, 10.73～48.19 kg/(hm~2·a); P, 0.61～3.70 kg/(hm~2·a); K, 6.66～39.61 kg/(hm~2·a); Ca, 17.90~20.91 kg/(hm~2·a) and Mg, 3.21～9.85 kg/(hm~2·a) respectively. It was concluded that faster nutrient release of leaf litter and its greater amount in the natural broadleaved forest were beneficial to nutrient recycling and soil fertility maintenance than monoculture coniferous plantations.教育部高等学校优秀青年教师奖资助项目;; 教育部高等学校骨干教师资助计划资助项目 ;; 福建省重大基础研究资助项目 (2 0 0 0 F 0 0 4)~

Carbon and nutrient pools of forest floor in native forest and monoculture plantations in subtropical China

通过对福建三明格氏栲天然林及在其采伐迹地上营造的 33年生格氏栲人工林和杉木人工林枯枝落叶层现存量与季节动态、C库及养分库的研究表明 ,格氏栲天然林、格氏栲人工林和杉木人工林枯枝落叶层现存量分别为 8.99t· hm- 2 、7.5 6t· hm- 2 和 4 .81t· hm- 2 ;枯枝落叶层中叶占现存量的比例分别为 6 4 .96 %、6 1.38%和 38.0 5 % ,枝占比例分别为 31.5 9%、37.83%和 4 2 .6 2 %。格氏栲天然林与人工林枯枝落叶层现存量最大值均出现在春季 ,而杉木人工林枯枝落叶层现存量最大值出现在夏季。格氏栲天然林枯枝落叶层 C贮量为 4 .0 2 t· hm- 2 ,分别是格氏栲人工林和杉木人工林的 1.2 2倍和 1.77倍 ;格氏栲天然林和人工林枯枝落叶层 C库与杉木人工林的差异均达到显著水平 (P<0 .0 5 )。格氏栲天然林、格氏栲人工林和杉木人工林枯枝落叶层养分贮量分别为 138.4 2 kg· hm- 2 、113.5 6 kg· hm- 2 和 72 .39kg· hm- 2 ;除 Mg外 ,格氏栲天然林枯枝落叶层中各种养分贮量均最高。与人工林... 【英文摘要】 In the last decades, large-scale native forests have been converted to fast-growing and high yield commercial forest plantations to meet the demands for timber, fuel material, and other forest products. Some silvicultural measures, such as planting pure stands, clear cutting and slash burning, are widely applied during this conversion. Yield decline and land deterioration in such disturbed ecosystem has become serious. In this context, the ecological comparisons between native forests and monoculture planta...福建省重大基础研究资助项目 (2 0 0 0 F0 0 4) ;; 高等学校优秀青年教师教学科研奖励计划资助项目~

NUTRIENT CYCLING OF N AND P BY A MIXED FOREST OF CUNNINGHAMIA LANCEOLATA AND TSOONGIODENDRON ODORUM IN SUBTROPICAL CHINA

通过对福建三明 2 7年生杉木 (Cunninghamialanceolata) 观光木 (Tsoongiodendronodorum)混交林 (混交比例2 :1)及杉木纯林群落N、P养分循环进行为期 2年的研究。结果表明 ,混交林中杉木和观光木地上各组分的N、P含量大小均为叶 >活枝 (或皮 ) >枯枝 >干 ,而根系的则随径级的减小而增大 ,且观光木各组分的N含量均高于杉木的 ;混交林群落的N、P总积累量达 5 85 .2 2 3kg·hm-2 和 12 8.784kg·hm-2 ,分别是纯林群落的 1.5倍和 1.3倍。混交林群落N、P养分年归还量达 75 .740kg·hm-2 和 5 .493kg·hm-2 ,分别是杉木纯林的 113 .0 %和 79.6 %。混交林通过凋落物、降水淋溶和细根枯死 3种途径的N归还量分别占群落总归还量的 6 7.1%、8.4%和 2 4.5 % ,而纯林的则分别为 6 9.3 %、8.1%和 2 2 .6 % ;混交林 3种途径的P归还量分别占群落总归还量的 6 4.0 %、7.5 %和 2 8.5 % ;而纯林则为 74.8%、5 .3%和 19.9%。混交林中林下植被层的N、P归还量分别占群落总归还量的 14.8%和 37.3 % ;而纯林的则为 2 9.5 %和 5 9.4%。混交林群落的N、P富集率和利用系数均低于纯林的 ,而周转期则均大于纯林的。混交林群落的P吸收系数小于纯林的 ,而循环系数则高于纯林的 ,但其两者的N吸收系数和循环系数则相似。A study on the cycling of N and P in a pure forest of Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook. and a Chinese fir_ Tsoongiodendron odorum Chun mixed forest (2 Chinese fir: 1 T. odorum ) over two years was carried out in Sanming, Fujian, China. For both Chinese fir and Tsoongiodendron odorum, the concentrations of N and P in aboveground fractions were in the order of leaves>living branches (or stem bark)>dead branches> stem wood, and those in roots increased with an increase in root diameter. N concentrations in various fractions of T. odorum were higher than their respective values for Chinese fir. The standing crops of N and P in the mixed stand were up to 585.223 kg·hm -2 and 128.784 kg·hm -2 , being 1.5 and 1.3 times as much as that in the pure stand, respectively. The annual return of N and P amounted to 75.740 and 5.493 kg·hm -2 in the mixed forest, respectively, being 113.0% and 79.6% of that in the pure forest. The fractions of annual N return through litterfall, rain leaching and fine root turnover were 67.1%, 8.4% and 24.5% in the mixed forest, respectively, and the corresponding values were 69.3%, 8.1% and 22.6% in the pure forest. These three pathways contributed to 64.0%, 7.5% and 28.5% of total P return in the mixed forest, and 74.8%, 5.3% and 19.9% in the pure forest, respectively. 14.8% of N return and 37.3% of P return in the mixed forest, and 29.5% of N return and 59.4% of P return in the pure forest were derived from the undergrowth vegetation. For both N and P elements, the enrichment ratios and the utilization coefficients were lower, and the recycling periods were higher in mixed forest than in pure stand. For P, the absorption coefficient was lower, and the cycling coefficient was higher, in mixed forest than in pure forest, while there were no significant differences for those of N between the two forests.中国博士后科研基金;; 福建省科委重大基础研究项目 ( 2 0 0 0_F_0 0 4);; 高等学校骨干教师资助计划项

Litter production, nutrient return and leaf-litter decomposition in natural and monoculture plantation forests of Castanopsis kawakamii in subtropical China

通过对中亚热带格氏栲天然林 ( natural forest of Castanopsiskawakamii,约 1 5 0年生 )、格氏栲和杉木人工林 ( monoculture plantations of C.kawakamii and Cunninghamia lanceolata,33年生 )凋落物数量与季节动态、养分归还及凋落叶分解与其质量的关系为期 3a的研究表明 ,林分年均凋落量及叶所占比例分别为 :格氏栲天然林 1 1 .0 1 t/hm2 ,5 9.70 t/hm2 ;格氏栲人工林 9.5 4 % ,71 .98% ;杉木人工林 5 .47t/hm2 ,5 8.2 9%。格氏栲天然林与人工林凋落量每年只出现 1次峰值 ( 4月份 ) ,而杉木林的则出现 3次 ( 4或5月份、8月份和 1 1月份 )。除杉木林的 Ca和格氏栲人工林的 Mg年归还量最大外 ,N、P、K及养分总归还量均以格氏栲天然林的为最大 ,杉木人工林的最小。分解 1 a后格氏栲天然林中格氏栲叶的干重损失最大( 98.1 6% ) ,杉木叶的最小 ( 60 .78% )。C/N及木质素 /N比值与凋落叶分解速率呈显著负相关 ,而 N、水溶性化合物初始浓度与分解速率呈显著正相关。与针叶树人工林相比 ,天然林的凋落物数量大、养分归还量高、分解快 ,具有良好自我培肥地力的能力。因此 ,保护和扩大常绿阔叶林资源已成为南方林区实现森林可持续经营的重要措施之一。The amount and pattern of litterfall, its nutrient (N, P, K, Ca and Mg) returns, and leaf-litter decomposition associated with its quality were studied in a natural forest of Castanopsis kawakamii (NF) and adjacent monoculture plantations of C. kawakamii (CK) and Chinese fir (Cunninghamia lanceolata, CF) in Sanming, Fujian, China. Mean annual total litterfall over 3 years of observations (from 1999 to 2001) was 11.01 t·hm -2 in the NF, 9.54 t·hm -2 in the CK and 5.47 t·hm -2 in the CF respectively. Of the total annual litterfall in the three forests, leaf contribution constituted 59.70%, 71.98% and 58.29%, respectively. Litterfall in the NF and CK showed similar litterfall pattern with a distinct peak in April of each year. While for the CF, the litterfall peaks occurred in April (or May), August and November, respectively. Except for the highest annual Ca returns in the CF and Mg returns in the CK, the three forests could be arranged in this sequence with respect to annual nutrient returns: NF>CK>CF. The annual percent leaf litter mass loss was the highest for C. kawakamii in the NF (98.16%) and the lowest for Chinese fir (60.78%). Ratios of C/N and lignin/N had significantly negative influences on decay rate coefficients, while initial N and water soluble compounds exerted significantly positive influences. The results of this study demonstrate that the natural forest has a greater capability for maintaining site productivity than monoculture plantations due to higher amount and quality of litter coupled with greater nutrient returns and faster litter decomposition. Therefore, conservation of the natural forest is recommended as a practical measure in forest management to realize sustainable development of forestry in mountainous areas of southern China.中国博士后科研基金资助项目;; 教育部高等学校优秀青年教师奖资助项目;; 教育部高等学校骨干教师资助计划资助项目;; 福建省重大基础研究资助项目 ( 2 0 0 0 F0 0 4)~

Nutrient dynamics of decomposing leaf litter in natural and monoculture plantation forests of Castanopsis kawakamii in subtropical China

通过对中亚热带格氏栲天然林 (natural forest of Castanopsis kawakamii,约 15 0 a)、格氏栲和杉木人工林 (monocultureplantations of C.kawakamii and Cunninghamia lanceolata,33年生 )凋落叶分解过程中养分动态的研究表明 ,各凋落叶分解过程中 N初始浓度均发生不同程度的增加后下降 ;除格氏栲天然林中其它树种叶和杉木叶 P浓度先增加后下降外 ,其它均随分解过程而下降 ;除杉木叶外 ,其它类型凋落叶的 Ca和 Mg浓度呈上升趋势 ;凋落叶 K浓度均随分解过程不断下降。养分残留率与分解时间之间存在着指数函数关系 xt=x0 e- kt。凋落叶分解过程中各养分释放常数分别为 :N (k N) 0 .6 78～ 4 .0 88;P (k P)0 .6 2 1～ 4 .30 8;K(k K) 1.4 0 8～ 4 .4 2 1;Ca (k Ca) 0 .799～ 3.75 6 ;Mg (k Mg) 0 .837～ 3.894。除杉木叶外 ,其它凋落叶分解过程中均呈 k K>k P>k N>k Mg>k Ca的顺序... 【英文摘要】 Nutrient dynamics of decomposing leaf litter was studied in two 33-year-old plantations, Chinese fir (Cunninghamia lanceolata, CF) and Castanopsis kawakamii (CK), and compared with that of an adjacent natural forest of Castanopsis kawakamii (NF, ~150 year old) in Sanming, Fujian, China. During the decomposition, varying degree of initial increase followed by decrease of N concentrations was observed in leaf litter, while initial increase and then decrease of P concentration was only found in leaves of other...教育部高等学校优秀青年教师奖资助项目;; 教育部高等学校骨干教师资助计划资助项目 ;; 福建省重大基础研究资助项目 (2 0 0 0 F 0 0 4)~

A Review on Litter Decomposition in Forest Ecosystem

杨玉盛为通讯作者。[中文文摘]系统评述森林凋落物的分解过程、凋落物分解及养分释放的影响因素、分解研究的方法等。森林凋落物的分解既有物理过程,又有生物化学过程,一般由淋溶、自然粉碎、代谢作用等共同完成。凋落物分解过程先后出现分解速率较快和较慢2个阶段,元素迁移一般呈现淋溶-富集-释放的模式。凋落物分解主要受气候、凋落物性质、微生物和土壤动物的影响,气候是最基本的影响因素,常用实际蒸散(actualevapotranspiration简称AET)作为指标。凋落物分解速率呈明显的气候地带性,与温度、湿度等紧密相关。从全球尺度来讲,凋落物质量对分解速率的影响处于次要地位,但在同一气候带内因AET变化较小,则起了主导作用。N、P和木质素浓度、C/N、C/P、木质素与养分比值是常见的凋落物质量指标,其中C/N和木质素/N最能反映凋落物分解速率。凋落物化学性质对其分解的影响作用又与分解阶段有关。凋落叶中N、P、K初始浓度高使得初期分解较快,而后期分解放慢。土壤理化性质及微生物区系也将不同程度地影响凋落物分解。尼龙网袋法(litterbagmethod)操作简单,是野外测定森林凋落物分解速率最常用的方法。除此之外,缩微试验也得到了广泛应用。目前普遍采用的衡量凋落物分解速率大小的指标主侧重以下方向 :长期的定位观测 ;采用相对统一的研究方法 ,获得可比性强的数据进行综合 ;深化凋落物分解机理研究 ;探讨全球气候变化对森林凋落物分解的影响 ;评价营林措施 (如林分皆伐、造林、施石灰和肥料等)对凋落物分解与养分释放的调节作用。[英文文摘] Decomposition of forest litter and simultaneous release of bioelements is one of the fundamental pathway of the flow of nutrient and energy in forest ecosystems, and an important component of the global carbon budget. The aim of this review is to summarize the changes of nutrient and chemical components during the decomposition, the factors controlling litter decay rate and its measurement. Decomposition of plant litter refers to the physical and chemical processes involved in reducing litter to its elemental chemical constituents. It includes two stages. First , litter is broken down by detritivores to small pieces which can be chemically reduced. Second , through the activities of micro-organisms (bacteria and fungi) these small pieces of organic matter are further reduced and mineralized into basic inorganic molecules. Also the course of nutrient dynamics during decomposition often can occur in three sequential phases , including an initial nutrient release through leaching , a net immobilization of nutrients by decomposer microorganisms and nutrient release from the litter , usually at a rate paralleling mass loss. However , the pattern of immobilization and release varies among species and ecosystems , and any particular litter type may not show all three phases. Litter decomposition rates are controlled by climate , litter chemistry , and by soil organisms. Climate has a direct effect on litter decomposition due to the effects of temperature and moisture. However , as a result of the climatic control of soil formation and nutrient cycling , it is to be expected that climate also has an indirect effect through the climatic impact on litter chemistry. Actual evapotranspiration (AET) is used as an index for the climatic control on decomposition. Mean AET in the humid tropical region is higher than in both the temperate and the mediterranean region and this results in rapid decomposition of litter.教育部高等学校优秀青年教师奖资助项目、教育部高等学校骨干教师资助计划资助项目

Content and distribution of unprotected soil organic carbon in natural and monoculture plantation forests of Castanopsis kawakamii in subtropical China

通过对福建三明格氏栲天然林及在其采伐迹地上营造的 33年生格氏栲人工林和杉木人工林土壤非保护性有机 C含量及分配的研究 ,结果表明 ,格氏栲天然林 0～ 10 0 cm土层内土壤有机 C贮量分别是格氏栲人工林和杉木人工林的 1.17倍和1.35倍 ,轻组有机 C贮量分别是后两者的 1.6 4倍和 2 .16倍 ,而颗粒有机 C贮量则分别是后两者的 1.6 0倍和 3.4 3倍 ,其土壤轻组有机 C和颗粒有机 C的分配比例亦显著高于后两者。不同林分间差异均以 0～ 10 cm土层为最大 ,该层格氏栲天然林土壤有机 C含量分别是格氏栲和杉木人工林的 1.5 2倍和 1.6 3倍 ,轻组有机 C含量分别是后两者的 1.70倍和 2 .14倍 ,而颗粒有机C含量则分别是后两者的 2 .18倍和 4 .85倍。这种差异与经营人工林时进行皆伐、炼山、整地等对林地干扰强度较大、幼林郁闭前产生水土流失及凋落物、枯死细根归还量减少等有关。土壤轻组有机 C和颗粒有机 C可作为土壤有机 C库变化的较为敏感指标 ,同时亦可指示土壤肥力演变。 【英文摘要】 Soil organic carbon (SOC) pool plays an important role in mitigating the rise of atmospheric CO_2. Due to its relatively unprotected (biochemical and physical) status, the unprotected SOC, be measured as either the light fraction (LFOC) or particulate organic carbon (POC), is sensitive to management practices and could contribute highly to rise in atmospheric CO_2 when inappropriate managements are employed. In South China, large-scale native forests have been converted to fast-growth and high yield commerc...教育部高校优秀青年教师教学科研奖励计划资助项目 ;; 福建省基础研究重大资助项目 (2 0 0 0 -F-0 0 4)~

Standing Crop of Energy in Ormosia xylocarpa Community

在生物量调查和热值测定的基础上 ,研究了三明莘口教学林场 34年生的木荚红豆群落的能量现存量。结果表明 :木荚红豆群落地上部分各组分的灰分含量、干重热值 (GCV)、去灰分热值 (AFCV)均以叶最高 ;地下部分的灰分含量、GCV、AFCV基本随根径的减小而增加。木荚红豆群落的灰分含量平均值乔木层 灌木层 >草本层 ,其群落的能量现存量为 4839.2 0× 1 0 9J/hm2 ,其中地上部分为 41 70 .92× 1 0 9J/hm2 (占86.1 9% ) ,地下部分为 489.1 0× 1 0 9J/hm2 (占 1 0 .1 1 % ) ,群落的能量现存量 96.30 %分布在乔木层 ,其分布与生物量的分布基本一致Based on the measurement of biomass and the caloric values of plant samples,the standing crop of energy of a 34 year old Ormosia xylocarpa community,which is located in Sanming Xinkuo Tree Farm for teaching and research,was determined.Among the aboveground fractions ash contents and GCV and AFCV were the highest in the leaves of Ormosia xylocarpa .For the subterranean fractions,ash contents increased and GCV and AFCV decreased with the decrease of root diameter size.From tree layer,shrubs layer to herbs layer,the mean of ash content increased,while those of GCV and AFCV decreased.The standing crop of energy in Ormosia xylocarpa forest ecosystem was 4 839.20×10 9 J/hm 2,and that of the aboveground and subterranean fractions was 4 170.92×10 9 J/hm 2(86.19%)and 489.10×10 9 J/hm 2 (10.11%) respectively.96.30% of the standing crop of energy owed to tree layer.It accorded with the distribution of biomass of Ormosia xylocarpa community.中国博士后科研基金;; 福建省科委重大基础研究项目 (2 0 0 0 -F -0 0 4);; 高等学校骨干教师资助计划资助项

Litter production, seasonal pattern and nutrient return in seven natural forests compared with a plantation in southern China

The amount and pattern of litterfall and its nutrient return were studied in seven natural forests of Schima superba Gardn. and Champ. (SCS), Castanopsis fabri Hance (CAF), Tsoongiodendron odorum Chun (TSO), Cinnamomum chekiangense Nakai (CIC), Altingia gracilipes Hemsl. (ALG), Castanopsis carlesii (Hemsl.) Hayata (CAC) and Pinus massoniana D. Don (PIM), and compared with that of an adjacent 29-year-old plantation of Chinese fir (Cunninghamia lanceolata Lamb.) (CUL) in Jianou, Fujian, China. Mean annual total litterfall over 3 years of observations varied from 4.63 Mg ha(-1) in the CUL to 8.85 Mg ha(-1) in the PIM; of this litterfall, the leaf contribution ranged from 62 to 73 per cent. Litterfall in the CAF, ALG and CAC showed an unimodal distribution pattern, while for the five other forests, the litterfall pattern was multi-peak. The rank order of the eight forests, according to nutrient return mass with the exception of P, was different from the order when rank was according to total mass of litterfall. The highest annual N, K and Ca returns from total litterfall were noticed in the TSO, the CAF and the CUL, respectively. The amounts of P and Mg potentially returned to the soil were the highest in the PIM. The leaf fraction provided greater potential returns of N, P, K, Ca and Mg to the soil than other litter fractions. The results of this study demonstrate that natural forests have a greater capability for maintaining site productivity than the monoculture coniferous plantation, due to higher amount of above-ground litter coupled with greater nutrient returns; therefore conservation of natural forests is recommended as a practical measure in forest management to realize sustainable development of forestry in mountainous areas of southern China