Dynamics of nutrient and energy for fine roots of Casuarina equisetifolia plantations on coastal sandy soil

2005年1月到2005年11月对福建省惠安县赤湖林场不同林龄木麻黄人工林细根养分和能量的季节动态进行了观测,结果表明:(1)6种元素的含量在不同林龄木麻黄细根中都具有明显的季节变化。各林龄细根的N含量一般在冬夏季节较高,且死细根的N浓度高于相同林龄的活细根,除12林龄活细根P浓度在7月份有最大值外,其他各林龄活、死细根在一年中呈波动性下降,K含量在冬季较高,而在其他季节变化幅度不大,除5林龄活细根和18林龄死细根在3月份和7月份有两个峰值外,其他林龄细根Ca含量随季节变化较小,Mg含量随季节变化总体呈下降趋势,而在11月份上升;各林龄C则呈波浪形变化;(2)随着林龄的增大,细根N、P、Mg含量的变化模式相似,都呈先增加,后降低,再增加的趋势,K和Ca含量变化趋势相似,但变动幅度存在差别,C则呈波浪形变化;(3)随着季节的变化,灰分、干重热值和去灰分热值呈"V"形变动,一年中都存在两个峰值,分别在3月份和7月份或9月份;(4)灰分、干重热值和去灰分热值随林龄的增大表现为波浪形增加。由此可见,不同森林类型的细根养分和能量动态具有季节和林龄的特殊性,在进行整个地区森林生态系统物质循环和能量流动研究时,应考虑不同森林类型的特性。The seasonal dynamics of nutrient and energy of fine roots in C.equisetifolia plantations of different ages was studied at Chihu forestry farm of Hui'an county,Fujian province from January to November in 2005.We obtained the following results:(1)There was significant seasonal dynamics of six elements in the fine roots of different aged C.equisetifolia plantations.N concentration of dead fine roots was higher than that of living fine roots,and was relatively higher in summer and winter.P concentration of fine roots fluctuated with a decreasing trend except for the living fine roots of 12 year-old plantation.K concentration was higher in winter than in the other seasons.The highest Ca concentration in March and July was found in living fine roots of 5 year-old plantation and dead fine roots of 18 year-old plantation,while Ca concentration remained little change for other aged plantations.Mg concentration decreased from January to September and then increased in November.C content fluctuated with time.(2)The similar trend was found for N,P and Mg;and for K and Ca,respectively;C concentration fluctuated with plantation age.(3)The ash content,gross caloric values and ash free caloric values changed with "V" type,and were relatively high in March and July or September,respectively.(4)The ash content,gross caloric values and ash free caloric values tended to increase with the increasing plantation age.It was concluded that the nutrient and energy dynamics of fine roots varied with seasons and plantation ages.To discuss matter cycling and energy flow of forest ecosystems,we should pay attention to these characteristics of different stands.国家“十一五”科技支撑计划资助项目(2006BAB03A14-01);; 福建省科技重大资助项目(2006NZ001-2);; 国家林业局南方山地用材林培育重点实验室资助项目~

Fine Root Biomass and Dynamics of Casuarina equisetifolia Plantations on Coastal Sandy Soil

2005年1月到11月对福建省惠安县赤湖林场不同林龄木麻黄人工林细根的生物量及其动态特征进行了研究.结果表明,24a生木麻黄林细根生物量分别占其地下部分生物量和林分总生物量的53.1%和3.8%;活细根的生物量随林龄的增大而逐渐增加,至30a林龄时达到最大值12.373thm-2,而后逐渐下降,死细根的生物量则呈现一直增大的趋势,木麻黄人工林细根的生物量与林分地上部分的生长具有显著的相关关系;细根生物量具有明显的季节动态,各林龄无论活细根还是死细根都表现为双峰型,3a生和18a生的活细根出现在1月和7月,而12a生出现在3月和7月,对于死细根,12a生和18a生的两个峰值出现在3月和7月,5a生则出现在7月和11月.各林龄木麻黄防护林活、死细根密度垂直分布呈单峰型,最大值出现在表层的0~10cm土层中,后随土层厚度增加逐渐减少,其中5a林龄细根生物量随土层深度增加而减少表现最为明显.在0~10cm土层中的活、死细根生物量分别占全部活细根生物量的51.9%和死细根生物量的53.3%,活细根生物量的84.6%和死细根生物量的82.8%分布在0~30cm的土层中.以后随着林龄的增加,表层土壤中细根生物量的比重降低而深层的比重增加.图3表2参31Fine root biomass and its dynamic characteristics of different aged Casuarina equisetifolia plantations on coastal sandy soil were studied in the Chifu Forestry Farm of Huian County, Fujian. The results showed that the fine roots of 24-year-old plantation accounted for 53.1% of the total underground biomass and 3.8% of the total amount of plantation, respectively; the standing crop of living fine roots increased as the forest aging until its maximum reached 12.373 t hm-2 at 30-year-old, then decreased gradually, while the biomass of dead fine roots increased all along as the forest aging. The fine roots biomass had remarkable correlation with the growth of the above-ground. The fine roots biomass was found with remarkable seasonal dynamics that the standing crop of living and dead fine roots of different aged plantations both were shown with double peaks, while the maximum occurred in different seasons for different aged plantations. The maximum of living fine roots of 5-and 18-year-old plantations occurred separately in January and July, while those of 12-year in March and July. As to the dead fine roots, those of 12-and 18-year occurred in March and July, and 5-year in July and November. The vertical distribution of living and dead fine roots at soil depth was shown with single peak for C. equisetifolia plantations, being concentrated at 0~10 cm, and then decreased with depth gradually. This trend was obvious for 5-year-old plantation. The biomasses of living and dead fine roots at 0~10 cm accounted for 51.9% and 53.3% of the totals, respectively. The 84.6% of living and 82.8% of dead fine roots concentrated at the depth of 0~30 cm. The proportion of fine roots decreased in topsoil and increased in deep soil along with aging of the forest. Fig 3, Tab 2, Ref 31国家“十五”科技攻关项目(No.2004BA516A15-13);; 国家林业局南方山地用材林培育重点实验室资助项目~

Study on C, N and P absorption by artificial Kandelia candel mangrove forests at Yundang Lake in Xiamen

本研究以福建厦门市筼筜湖不同林龄的人工秋茄（Kandeliacandel）红树林为对象，探索红树林种植对筼筜湖N、P的吸收能力，以此来估算筼筜湖红树林对于湖水富营养化的缓解能力。主要结果如下： （1）筼筜湖不同林龄秋茄红树林的植株生物量和凋落物量 本研究的筼筜湖10yr、11yr、12yr和14yr秋茄红树林种植面积分别为2760、2460、1700和667m2。不同林龄秋茄红树林单位面积植株生物量14yr＞12yr＞11yr＞10yr，单位面积凋落物年产量也是14yr＞12yr＞11yr＞10yr。10yr、11yr、12yr和14yr秋茄红树林的植株生物量（单位面积植株生物量×种植面积...Effects of artificial Kandelia candel mangrove forests on NP absorption were studied at Yundang Lake in Xiamen. Main results are as follows. (1) Plant biomass and litter production of mangrove forests Areas of 10 yr, 11 yr, 12 yr and 14 yr Kandelia candel mangrove forests are 2760, 2460, 1700 and 667 m2, respectively. Both plant biomass and litter production per m2 of Kandelia candel mangrove fo...学位：工学硕士院系专业：海洋与环境学院_环境工程学号：2262010115136

Dynamics of tannin concentration and nutrient resorption for branchlets of Casuarina equisetifolia plantations at different ages

通过对福建省惠安县不同林龄短枝木麻黄人工林不同发育阶段小枝单宁含量及氮磷再吸收率的研究,探讨了短枝木麻黄林分发育过程中的营养保存策略。结果表明,幼龄林(5年生)成熟小枝中的总酚(TP)、可溶性缩合单宁(ECT)总缩合单宁(TCT)含量及蛋白质结合能力(PPC)显著高于成熟林(21年生)和衰老林(38年生)。随着林分发育,成熟小枝中n含量显著升高,而P含量呈降低趋势。不同发育阶段林分成熟小枝中n∶P比均大于20,且随着林龄的增加而升高。磷再吸收率(PrE)显著高于氮再吸收率(nrE),均以成熟林分最高。这表明短枝木麻黄小枝单宁含量与养分再吸收受林龄影响,其养分保存机制会随着林分生长发育的变化而进行调节。Casuarina equisetifolia is characterised by high primary productivity in coastal sandy soils,which are generally low in nutrient contents.High tannin production and nutrient resorption may be important strategies for C.equisetifolia in coastal environments.Despite the widespread planting and known ecological and physiological properties of C.equisetifolia,there is scant information about the nutrient resorption patterns and tannin concentrations for branchlets of C.equisetifolia plantations during stand development.Since plant ecophysological traits are associated with ageing,tannin content and nutrient resorption efficiency could change with stand development.Therefore,tannin level and nutrient resorption of C.equisetifolia at different developmental phases(juvenile,mature and senescent) were examined to evaluate possible nutrient conservation strategies under nutrient limitation in Huian County,Fujian Province.The results showed that total phenolics(TP) contents,which were in the order juvenile stand > senescent stand > mature stand for senescent branchlets and decreased from 218.52 to 180.49 mg / g during stand development for mature branchlets,decreased during branchlet senescence in all stands.The extractable condensed tannin contents(ECT) in mature and senescent branchlets of C.equisetifolia were juvenile stand > senescent stand > mature stand.The ECT contents of C.equisetifolia increased during branchlet senescence both in the mature and senescent stands but decreased in the juvenile stand.The protein-bound condensed tannin(PBCT) contents of branchlets increased during senescence in juvenile and mature stands and remained the same in senescent stand.The fibre-bound condensed tannins(FBCT) of branchlets increased during senescence in mature stand and did not change in juvenile and senescent stands.Total condensed tannin(TCT) followed similar pattern as ECT during stand development.Protein precipitation capacity(PPC) in mature and senescent branchlets were significantly higher in juvenile stand than in mature and senescent stands.PPC decreased during branchlet senescence in the three stands.Significant positive linear correlations were found between PPC and TP or TCT.Nitrogen(N) concentrations both in mature and senescent branchlets obviously increased during stand development.Phosphorus(P) concentrations in mature branchlets were similar in juvenile and mature stands but lower in senescent stand.Phosphorus concentrations in senescent branchlets of juvenile stand were significantly higher than those of mature and senescent stands.Nitrogen: phosphorus ratios(N ∶P ratios) of mature branchlets,were all above 20,also increased during stand development.Nitrogen resorption efficiencies(NRE) in three stands were basically below 50%,the lowest in senescent stand.Phosphorus resorption efficiencies(PRE) were above 70% with the highest in mature stand(78.08%).There were significant negative correlations between N and P concentrations in mature and senescent branchlets.Nitrogen resorption efficiency had a particular strong relationship with the N ∶P ratios of branchlets.On the other hand,PRE was not significantly related to N ∶P ratios of branchlets.There were significant correlations between TP or TCT and N or P concentrations in branchlets except for the relationship between TCT and P concentrations in senescent branchlets.The above results indicated that the tannin level,nutrient concentration and resorption were affected by stand age.C.equisetifolia could adjust their nutrient conservation with stand development at intraspecific level.国家自然科学基金项目(41201293;41176092); 国家“十一五”科技支撑计划项目(2009BADB2B0302); 国家林业局南方山地用材林培育重点实验室和福建省森林培育与林产品加工利用重点实验室资助项

Absorption and enrichment of heavy metals by Casuarina equisetifolia of different stand ages in a coastal zone

为研究不同林龄木麻黄对重金属的吸收与富集作用,用ICP-MS测定了福建东山县国有防护林场10、16、20、30年生木麻黄小枝、细根、凋落物及林地土壤中的5种重金属(Cr、Cu、zn、Cd和Pb)含量。结果表明,木麻黄对不同重金属的吸收能力不同,从高到低为zn>Cr>Pb>Cu>Cd;木麻黄细根中Cr和Cu、Pb,fE和Cu,zn和Cd具有明显的协同作用;各林龄木麻黄对重金属均具有一定的耐性,对Cu、zn、Cd、Pb有很好的富集作用;20年生木麻黄的重金属年积累量最高;说明木麻黄对重金属的净化作用具有极大的潜力,20年生木麻黄作用最为明显。To assess the absorption and enrichment of heavy metals by Casuarina equisetifolia,the concentrations of heavy metals including Cr,Cu,Zn,Cd and Pb in branchlet,fine root,litter and soil of C.equisetifolia forests at four ages( 10,16,20,30) were determined.The results showed that the enrichment degree of the heavy metals in C.equisetifolia ranked as Zn > Cr> Pb > Cu > Cd.Correlation analysis showed that Cr and Cu,Pb,Fe and Cu,Zn and Cd had significant synergies in the fine roots of C.equisetifolia.C.equisetifolia had a higher capability of absorbing and accumulating heavy metals.Annual accumulation of heavy metals was highest in20 years old C.equisetifolia.Our results indicate that C.equisetifolia has a great potential for reducing the pollution of heavy metals,especially for the 20 years old forest.国家自然科学基金项目(41176090); 国家科技支撑项目(2009BADB2B0302)资

Comparisons of Litter Fall and Leaf Consumption by Crabs between 24 and 48 Years Old Kandelia candel Mangrove Forests in Jiulongjiang Estuary

于2009年12月至2010年11月，以福建九龙江口恢复背景相似的24年生和48年生秋茄红树林为研究对象，采用野外现场实验的方法，研究林龄和滩位对秋茄红树林凋落物生产量、凋落物养分含量以及蟹类对凋落叶摄食量的影响。主要结果如下： （1）秋茄红树林凋落物生产量及养分含量的季节动态 24年生秋茄红树林凋落物的年产量为1324.88gDWm-2，其中凋落叶的年产量为860.04gDWm-2，约占总量的64%；落枝的年产量350.31gDWm-2，占凋落物总量的26%左右；落花的年生产量为100.38gDWm-2，占凋落物总量的7%；全年收集到的落果量为49.80gDWm-2占凋落物总量的3%左右...This thesis was focused on the effects of stand age and tide flat of Kandelia candel mangrove forests on litter fall production and nutrient concentration, and leaf consumption rate by crabs. (1) Dynamics of litter fall production and nutrient concentration From December 2009 to November 2010, seasonal dynamics of litter fall production were investigated within 24 and 48 years old K. candel man...学位：工学硕士院系专业：海洋与环境学院环境科学与工程系_环境工程学号：2262008115155

Comparisons of leaf litter decomposition and nutrient dynamics among Kandelia candel mangrove forests at different restoration stages in Jiulongjiang Estuary

本研究以福建九龙江口不同年份恢复的秋茄（Kandeliacandel）红树林为对象，并与天然成熟秋茄林进行比较，探索红树林生态系统凋落物分解动态随红树林植被恢复的变化情况，还通过野外实验与室内模拟相结合，对红树林植被恢复进程中凋落叶分解速率、养分释放等环节及其影响因素进行研究。主要结果如下： （1） 秋茄凋落叶分解动态和分解速率 于2010-2011年春季（3~5月）、夏季（6~8月）、秋季（9~11月）、冬季（12~2月），对九龙江口三片不同恢复阶段的人工秋茄林，种植时间分别为1998年（12yr）、1986年（24yr）、1962年（48yr），以及一片天然成熟秋茄林的凋落叶分解动态进...In order to explore decomposition dynamics of leaf litter in mangroves with the changes of mangrove vegetation recovery process, degradation rate, nutrient dynamics and their influencing factors of leaf litter were studied in Kandelia candel mangrove forests at different restoration stages in Jiulongjiang Estuary, China through a combination of field experiments and laboratory simulation. The main...学位：工学硕士院系专业：海洋与环境学院环境科学与工程系_环境工程学号：2262009115117