Effects of Clear-cutting and Slash Burning on Dynamics of Carbon and Nitrogen in Chinese Fir and Castanopsis fargesii Forests

作为重要商品林基地的我国亚热带地区，把大面积常绿阔叶林皆伐后进行全面火烧，是我国南方集体林区经营杉木人工林的主要营林技术环节之一，但大面积火烧将造成迹地养分损失、水土流失、土壤物理性质退化等。营林用火已在温带森林的规定火烧、热带地区的刀耕火种中得到大量研究。早期有关研究主要集中在火烧对N、P等森林生长限制元素的损失及其对森林长期生产力、水文状况、径流化学的影响上；随着人们对全球环境变化的关注，皆伐火烧对生态系统C、N循环的影响研究在近十几年逐渐受到重视，但目前有关皆伐火烧后我国亚热带地区常绿阔叶林C、N动态的研究未见报道。作为森林生态系统主要CO2源的土壤呼吸（约68±4PgC·a-1），它的...Chinese fir (Cunninghamia lanceolata) is one of the most important plantation tree species in China in terms of planting area, yield and timber usage. The history of managing this plantation exceeds 1000 years in China. In recent decades, many pure Chinese fir stands were established in the southern part of China for an expected highly economic return, leading to a sharp decline in the area of nat...学位：理学博士院系专业：生命科学学院生物学系_植物学学号：B20032600

Energy of forest floor in natural and monoculture plantation forests of Castanopsis kawakamii

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各组分热值及能量现存量的研究表明,格氏栲天然林、格氏栲人工林和杉木人工林枯叶的干重热值和去灰分热值从未分解层(L层)到半分解层(F层)均不断下降.格氏栲天然林枯枝落叶层能量现存量达16 125.72 kJ.m-2,分别比格氏栲人工林和杉木人工林枯枝落叶层能量现存量高24.29%和81.63%.在枯枝落叶层组成中,枯叶能量现存量所占比例最大,3种林分枯枝落叶层枯叶分别占63.76%、56.32%和43.64%;枯枝的能量现存量次之. 【英文摘要】 Caloric value and the standing crop of energy of forest floor 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.The results showed that gross caloric values of leaf litter in the NF,CK and CF were higher in the L layer than those in the F layer,which was the same for ash free caloric values.The standing crop of energy in forest floor of the NF was 16 125.72 kJ·m~(-2),being...高等学校优秀青年教师教学科研奖励计划资助项

Carbon and Nutrient Pools of Coarse Woody Debris in a Natural Forest and Plantation in Subtropical China

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粗木质残体现存量与季节动态、C库及养分库的研究表明,格氏栲天然林、人工林和杉木人工林粗木质残体现存量分别为1 32、0 4 6和0 2 3t·hm- 2 。3种林分粗木质残体现存量的季节变化模式均为夏季>冬季>秋季>春季。格氏栲天然林粗木质残体C贮量为0 78t·hm- 2 ,分别是格氏栲人工林和杉木人工林的4 1 1倍和7 0 9倍;格氏栲天然林粗木质残体C库与2种人工林间差异显著(P <0 0 5)。格氏栲天然林、人工林和杉木人工林粗木质残体养分贮量分别为1 4 1 6、2 90和0 95kg·hm- 2 ;格氏栲天然林粗木质残体中各种养分贮量均最高。与人工林相比,天然林粗木质残体现存量、C和养分贮量均最大。 【英文摘要】 During the past decades, large scale natural forests had been converted to fast growing and high yield commercial 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, were widely applied during this conversion. Yield decline and land deterioration in such disturbed ecosystems had become serious. In this context, the ecological comparisons between natural forests and plantations have...福建省重大基础研究项目 (2 0 0 0F0 0 4 ) ;; 高等学校优秀青年教师教学科研奖励计划资助

PRODUCTION, DISTRIBUTION AND NUTRIENT RETURN OF FINE ROOTS IN A MIXED AND A PURE FOREST IN SUBTROPICAL CHINA

研究了福建三明 2 7a生杉木观光木混交林和杉木纯林群落细根 (d <2mm)的生产力、分布和养分归还 .结果表明 ,混交林细根生物量、N、P养分现存量分别为 5 .381thm-2 、4 8.0 85kghm-2 和 4 .174kghm-2 ,分别比杉木纯林增加17.4 %、2 7.2 %和 2 0 .0 % .混交林细根的年净生产力达 4 .12 4thm-2 a-1,比纯林高出 16 .9% .混交林杉木和观光木细根均在表层土壤富集 ,而在较深层土壤两者分布具镶嵌性 ;与混交林杉木相比 ,纯林杉木土壤表层细根量较少 ,最大分布层次下移 .混交林中观光木细根的周转速率为 1.16 ,杉木为 0 .96和 0 .95 ;而林下植被层细根周转速率 (1.4 6～ 1.5 2 )均高于相应的乔木层 .混交林细根的年死亡量、N和P养分年归还量分别达 2 .119thm-2 、18.5 5 9kghm-2 和 1.5 6 5kghm-2 ,分别是纯林的 1.2 1倍、1.2 3倍和 1.14倍 ,其中林下植被细根占有较为重要位置 .对细根分布与土壤性质的相关分析表明 ,细根的垂直分布与土壤全N的相关性最强 (0 .87～ 0 .89) .图 1表 4参 32The studies on production, distribution and nutrient return of fine roots ( d <2 mm) in a mixed Chinese fir ( Cunninghamia lanceolata ) Tsoong' tree ( Tsoongiodendron odorum ) forest and a pure Chinese fir forest at age 27 were carried out in Sanming of Fujian, China. The standing crops of dry matter, N and P in fine roots of the mixed stand were 5.381 t hm -2 , 48.085 kg hm -2 and 4.174 kg hm -2 , 17.4 %, 27.2% and 20.0% higher than those of the pure stand, respectively. The fine root production in the mixed forest was up to 4.124 t hm -2 a -1 , 16.9% higher than that in the pure stand. Fine roots of Chinese fir and Tsoong' tree in the mixed forest both concentrated in the surface soil, and showed a vertical stratification in the subsoil. Compared with those in the mixed forest, fine roots of Chinese fir in the pure forest had a deeper rooting zone, with a lower root density in the superficial soil. The turnover rates of fine roots for Tsoong' tree and Chinese fir in the mixed stand, and Chinese fir in the pure stand, were 1.16, 0.96 and 0.95, respectively. The undergrowth species had higher root turnover rates than their respective tree layers (1.46 in the mixed forest and 1.52 in the pure stand). The annual mortality, annual return of N and P of fine roots in the mixed forest amounted to 2.119 t hm -2 , 18.559 kg hm -2 and 1.565 kg hm -2 , 1.21, 1.23 and 1.14 times as much as that in the pure forest respectively. Bulk density, moisture content, total N and humic C were strongly correlated with fine root density along the soil profile in the two forests, with total N giving the highest coefficients of determination. Fig 1, Tab 4, Ref 32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 0F0 0 4 );; 高等学校骨干教师资助计划;; 福建省自然科学基金 (B0 1 1 0 0 2 5)资助

LITTER DECOMPOSITION AND NUTRIENT RELEASE IN A MIXED FOREST OF CUNNINGHAMIA LANCEOLATA AND TSOONGIODENDRON ODORUM

通过福建省中亚热带杉木观光木混交林 (CunninghamialanceolataandTsoongiodendronodorummixedforest)和杉木纯林 (PureC .lanceolataforest)凋落物的分解和养分释放动态试验研究表明 ,凋落物各组分分解过程中干物质损失速率随时间而减小 ,分解 1年时以观光木叶的干重损失最大。各组分分解过程中N、P元素浓度增加而K和C元素浓度下降。混交林中各组分的养分释放速率大小为观光木叶 >混合样品 (等重量的观光木叶和杉木叶混合 )>杉木叶 >杉木小枝。不同元素的释放速率与干重损失速率大小为 :K >C >干重 >N≈P。混交林凋落物的年养分释放量 (kg·hm-2 ·a-1)为N 17.92 1,P 0 .715 ,K 10 .315 ,分别是纯林的 2 .0 3倍、1.73倍和 1.34倍。与纯林相比 ,混交林较高的年凋落物养分归还量和养分释放量有利于促进养分的再循环 ,这对维持混交林的地力有重要作用。Rate of litter weight loss and release of nutrient elements were investigated in a mixed forest of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) and Tsoong' tree (Tsoongiodendron odorum Chun) and a pure stand of Chinese fir in Sanming, Fujian. Chinese fir needle, branch, Tsoong' tree leaf and the mixture of Chinese fir needle and Tsoong' tree leaf were involved in the 510 day period of litter bag studies. Rate of weight loss slowed with time for all litter components, with the highest percent initial weight loss of 74.54% for leaf litter of Tsoong' tree at the first year. Concentrations of N and P appeared to increase and concentrations of K and C appeared to decrease during the decomposition. The four litter components could be arranged with respect to nutrient release rate in this sequence: leaf of Tsoong' tree > the mixed leaves > needle of Chinese fir > branch of Chinese fir. Nutrient elements and weight loss followed the release pattern: K >C >dry weight> N≈P. The total annual nutrient release of litter fall was N,17.921 kg·hm -2 ·a -1 ; P, 0.715 kg·hm -2 ·a -1 and K,10.315 kg·hm -2 ·a -1 respectively in the mixed forest, being 2.03, 1.73 and 1.34 times as much as that in the pure forest. It was concluded that the higher yield of litter production and the greater amount of nutrient release from litter in mixed forest were beneficial to nutrient cycling. Thus, a higher level of soil fertility would be expected for mixed forest than for pure forest.ThePost_doctorResearchFoundationofChina,theFoundationforUniversityKeyTeacherbytheMinistryofEducation,andtheResearch ProjectofBasicTheoryofFujianProvince ( 2 0 0 0F0 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~

GUO Jian-fen1; 2; YANG Yu-sheng2*; CHEN Guang-shui2; LIN Peng1 1 College of Life Science; Xiamen University; Xiamen; P. R. China 2 College of Geography Science; Fujian Normal University; Fuzhou; P. R. China;

尽管溶解有机碳(DOC)和溶解有机氮(DON)在森林养分循环中的作用日渐为人们所关注,但对它们的浓度及动态,特别是对亚热带森林DOC 和DON 的研究甚少。本文于2002 年通过野外天然降水及亚热带木荷和杉木人工林(monoculture plantations of Schima superba and Cunninghamia lanceolata,15 年生)穿透雨和树干茎流各水样的收集及室内各水样中DOC、NO3 -N、NH4 -N 和总溶解有机氮(TDN)浓度的测- +定,其中DON 浓度通过TDN 与NO3 -N、NH4 -N 的浓度差值来计算,- +结果表明,天然降水DOC 和DON 浓度分别为1.7 和0.13 mg·L-1。木荷人工林穿透雨DOC 和DON 浓度分别为11.2 和0.24 mg·L-1,高于杉木人工林的DOC 和DON 浓度(10.3 和0.19 mg·L-1)。杉木人工林树干茎流DOC 和DON 浓度(分别为19.1 和0.66 mg·L-1)明显高于木荷人工林(分别为17.6 和0.48 mg·L-1)。天然降水DOC 浓度的月变化不明显,而DON 浓度在夏季和秋季较高。... 【英文摘要】 Despite growing attention to the role of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in forest nutrient cycling, their monthly concentration dynamics in forest ecosystems, especially in subtropical forests only were little known. The goal of this study is to measure the concentrations and monthly dynamics of DOC and DON in precipitation, throughfall and stemflow for two planta- tions of Schima superba (SS) and Chinese fir (Cunninghamia lanceolata, CF) in Jianou, Fujian, China. Sample...This study was supported by the Teaching and Research Award program for MOE P. R. C. (TRAPOYT)

A Review on Litter Decomposition in Forest Ecosystem

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... 【英文摘要】 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 element...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

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)~