Analysis of Genetic Structure of Natural Populations of Castanopsis fargesii by RAPDs

Genetic diversity and population genetic structure in 188 individuals from five natural populations of Castampsis fargesii Franch. were studied by RAPD markers. Three hundred and eighty-five loci were identified with 41 oligonucleotide primers, out of which 157 loci were polymorphic and accounted for 40.78% of total genetic diversity at species level. Shannon's indices of diversity (I) and Nei's gene diversity ( h) were 0.459 7 and 0.296 at the species level, respectively. The result showed that genetic variation of C. fargesii populations mainly existed within populations. Genetic differentiation (Hsp-hpop)/Hsp estimated with Shannon's index of diversity and coefficient of gene differentiation (Gst) were 0.047 6 and 0.042 9 respectively, which were confirmed by the analysis of molecular variance (AMOVA). Therefore, it is apparent that within-population variation accounted for 94.97% and among-populations variation accounted for only 5.03% of the total genetic diversity. AMOVA also indicated that there was significant differentiation among populations as well as among individuals within a population.

Molecular Ecology of Lower Subtropical Species, Schima superba and Castanopsis chinensis in Three Succession Series Communities

Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.

Variation of SPAD values in uneven-aged leaves of different dominant species in Castanopsis carlessi forest in Lingshishan National Forest Park

The greenness （SPAD） of uneven-aged leaves of dominant species in the Castanopsis carlessi forest at different altitude gradients in Lingshishan National Forest Park, Fujian Province, China were measured by using portable chlorophyll meter SPAD-502. In addition, the correlation between SPAD value and the concentration of chlorophyll and foliar nitrogen was also investigated. Significant variations in SPAD values were found between the uneven-aged leaves of different dominant species and different altitude gradients. Regression analysis showed that SPAD value was significantly correlated with the concentration of chlorophyll and the content of foliar nitrogen, indicating that SPAD value could be indicators for foliar chlorophyll and nitrogen. It is suggested that SPAD meter is a useful tool for forest assessments in decision-making and operational nutrient management programs.

Genetic Diversity of Wild and Cultivated Populations of Castanopsis hystrix in China

[Objective] This study aimed to investigate the genetic variation of wild and cultivated populations of Castanopsis hystrix. [Method] Genetic variation of five wild populations and three cultivated populations of Castanopsis hystrix, was investigated with ISSR-PCR amplification. Totally, 151 individuals were selected and analyzed by amplification using nine pairs of ISSR primers screened. [Result] Each primer pair produced 7-20 bands and 122 polymorphic bands were obtained. At population level, ISSR diversity in the wild populations (P=59.84%, HPOP=0.182 7, I=0.285 6) was higher than which in cultivated ones (P=54.87%, HPOP=0.136 6, and I=0.219 8). The genetic differentiation coefficient among wild populations (GST) was 0.99. The similar population structure was found in three cultivated populations (GST=0.127 5). According to the UPGMA cluster analysis, the genetic distance among wild populations became larger with the increase of geographical distance. [Conclusion] Compared with other seed plants, with either a similar life history or various breeding system attributes, relatively low level of genetic diversity was observed in these five wild populations, which was caused by population size reduction and habitat fragmentation related to human activities. The formation of population structure may be explained by the species’ breeding system.

Comparison Experiment of Root Cutting to Castanopsis tibetana Hance between Different Provenances at Seedling Stage

Castanopsis tibetana of five different provenances （Jinxiu, Longsheng, Ziyuan, Hezhou and Leye） were selected as experimental materials to investigate the effects of treatments combining different root lengths and contents of rooting agent on the growth of C. tibetana after transplanting of seedlings. The results showed that, there were significant differences in the preserving rate of C. tibetana seedlings between different provenances and different treatments. Among the 5 treatments, the seedlings of Hezhou provenance showed the maximum annual increment of ground diameter, and the seedlings of Ziyuan provenance exhibited the maximum annual increment of seedling height. Therefore, the germplasm from Hezhou provenance might be better than those from other provenances.

Concentrations and seasonal dynamics of dissolved organic carbon in forest floors of two plantations （Castanopsis kawakamii and Cunninghamia lanceolata） in subtropical China

The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations of Castanopsis kawakamii and Chinese fir （Cunninghamia lanceolata） were assessed in Sanming, Fujian, China （26°11′30″N, 117°26′00″E）. Forest floor samples were taken in January, April, July and October in 2002 and divided into undecomposed material （horizon Oi）, partially decomposed organic material （horizon Oe）, and fully decomposed organic material （horizon Oa）. Upon collection. DOC concentrations of samples were analyzed by a High Temperature TOC. The results showed that the annual average DOC concentration of Chinese fir （1341.7 mg·kg^-1） in the forest floor was higher than that of Castanopsis kawakamii （ 1178.9 mg·kg^-1）. Difference in DOC concentrations was observed among three horizons of the forest floor. DOC concentration of forest floor in the two forests was the highest in horizon Oe. Seasonal trends of DOC concentrations in different horizons of forest floors were similar and the maximal value occurred in autumn （or winter）. The concentration and temporal change of DOC in studied forests were probably related to the variation in moisture, temperature, biological activity and quantity of organic matter in the forest floor.

Carbon Return and Dynamics of Litterfall in Natural Forest and Monoculture Plantation of Castanopsis kawakamii in Subtropical China

The amount of carbon returned through litterfall and its seasonal pattern 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 Province, China. Mean annual carbon return through total litterfall over 3 years (from 1999 to 2001) was 5.097 t穐m2 in the NF, 4.337 t穐m2 in the CK and 2.502 t穐m2 in the CF respectively. Of the total carbon return in the three forests, leaf contribution accounted for 58.96%, 68.53% and 56.12% and twig 24.41%, 22.34% and 26.18%, respectively. The seasonal patterns of carbon return from total litterfall and leaf-litter were quite similar among the three forests. A peak of carbon input from litterfall in the NF and the CK occurred in spring except for the highest annual C return through branch litter of the NF in summer, while the CF showed the maximum C return in summer. The results of this study demonstrate that the natural forest has a greater C return through litterfall than monoculture plantations, which is beneficial to the increase of soil organic matter storage and the maintenance of soil fertility.

Study on the Growth Law of 23-year-old Castanopsis fissa Plantation

This paper studies the growth law of 23-year-old Castanopsis fissa planta- tion in Haiming forest farm （Pingguo County, Baise City, Guangxi Province） with the method of stem analysis. The results show that the average DBH, tree height and volume of the 23-year-old C. fissa plantation are 19.4 cm, 20.4 m and 0.326 1 m3 respectively. The fast growing periods of DBH, tree height and volume are the 2^nd- 8^th, 6^th-11^th, 6^th-23^nd year. Annual increment curve and average increment curve of volume haven＇t intersected in the 23 years, which means the 23-year-old C. fissais plantation has not reached the quantitative mature age. The growth equations of DBH, tree height and volume are D=1.713 3T-0.050 6T2＋0.000 7T2-1.942 2, H= 1.925 7T-0.039 8T2-2.489 0, V=-0.010 4T-0.002 4T2-4.084 8e^-0.005 T2＋0.012 7. Ac- cording to the volume regression equation of Castanopsis fissa, it will reach quanti- tative maturity in the 24~ year.

Analysis of spatiotemporal variations in the characteristics of soil microbial communities in Castanopsis fargesii forests

Castanopsis fargesii is a good afforestation plants and various microorganisms play important roles in mediating the growth and ecological functions of this species.In this study,we evaluated changes in microbial communities in soil samples from C.fargesii forests.The phospholipid fatty acid(PLFA)biomarker method was used to obtain bacteria,fungi,actinomycetes,gram-positive bacteria(G?),gram-negative bacteria(G-),aerobic bacteria,and anaerobic bacteria to investigate spatiotemporal changes in microbial communities during the growing season.The results show that soil microorganisms were mainly concentrated in the upper 20-cm layer,demonstrating an obvious surface aggregation(P<0.05).Large amounts of litter and heavy rainfall during the early growing season resulted in the highest PLFA contents for various microorganisms,whereas relatively low and stable levels were observed during other times.The dominant species during each period were bacteria.G+ or aerobic bacteria were the main bacterial populations,providing insights into the overall trends of soil bacterial PLFA contents.Due to the relative accumulation of refractory substances during the later stages of litter decomposition,the effects of fungi increased significantly.Overall,our findings demonstrate that the main factors influencing microbial communities were litter,rainfall,and soil field capacity.

Relationship between the stoichiometric characteristics and leaf functional traits of Castanopsis hystrix in different ages

Both the stoichiometric characteristics and leaf functional traits can reflect the adaptability of plants to changes in the external living environment.In particular,for varying aged forest plants,the study of stoichiometric characteristics and leaf functional traits can reflect the plant’s life history strategy and its resource investment and allocation methods.In this paper,the 1.5-year-old,5-year-old,15-year-old and 20-year-old Castanopsis hystrix were selected as the research objects to investigate the trends of stoichiometry and leaf functional traits,and their synergistic changes were verified.The results showed that with the increase of age,the stability of C.hystrix stoichiometry gradually increased,and the functional traits also tended to invest in security.However,there was no synergistic change between the two,which might be attributed to the different sensitivity of the C.hystrix leaf to the environment at the life history level of 1.5-year-old to 20-year-old.

Ecological succession of a natural community of Castanopsis sclerophylla on Laoshan Island, China

Castanopsis sclerophylla was surveyed for its root turion capacity on Laoshan Island in Zhejiang Pro- vince and dispersion patterns of seedlings, genetic diversity and genetic variation coefficient was studied using a SSR （simple sequence repeat） molecular marker technique to explore the genetic diversity of C. sclerophylla （Lindl.） Schott as a community and evaluate the community＇s development. The results showed that C. sclerophylla had strong root turion capacity, of which type Re2 was the most frequent, accounting for 32.4 and 82.4 % of the seedlings under the stock plant were from within-community mating; the 6 pairs of SSR primers chosen yielded high resolution with 97.6 % polymorphic sites; the within-community genetic diversity was over 88.9 % with stock plants （0.49） 〉 seedling plants （0.45）. Apparently, C. scerophyllan on Laoshan Island, propagating mainly by root tufions, has developed high genetic diversity within a short period, keeping the community in a stage of stable growth and moving toward a climax community. The tillers, however, aggravate closing of the community so that it receives less pollen from outside. Within-community mating is thus reaching seriously high levels, which can lead to lower within-community genetic variation, a decline in DNA genetic diversity, and is bad for its development. Therefore, human interference should be taken to expand genetic exchange among communities.

日本山阴地区出云区Castanopsis cuspidata var.sieboldii天然林的植被结构——Ⅰ应用主成分分析法的林分和种类的排序

在日本西南部,Castanopsis Cuspidata Var.Sieboldii作为一种最有代表性的天然树种,通常由它构成暧温带常绿栎林的正个林冠。在从山口县长门州北部延伸到岛取县东部的山阴地区,以该树种占优势的天然林保留在靠日本海沿岸的圣词和寺庙周围。从植物群落学的观点出发,许多学者已经调查了这些森林(SHIOMI,1971;FUKOSHIMA与SUZUKI、1983;NAKANISHI等,1979;HATTORI等,1979)。但是他们只提出有关该森林属于何种群落类型的各种看法。

淋漓锥育苗技术初探

以福建省淋漓锥[Castanopsis uraiana(Hayata)Kanehira et Hatusima]种子为研究对象,研究不同贮种方法和处理对种子萌发的影响,观察记录苗木生长过程的变化。研究表明,自然干燥储藏的种子直接播种出苗率仅为5%;自然干燥储藏,播种前温水浸种24 h后播种的种子出苗率为21%;沙藏的种子出苗率则高达92%。沙藏下的淋漓锥种子出苗率最高。

Variation in litter decomposition-temperature relationships between coniferous and broadleaf forests in Huangshan Mountain, China

A study was conducted to identify the differences in the decompositions of leaf litter, lignin and carbohydrate between coniferous forest and broadleaf forest at 20℃ and 30℃ in Huangshan Mountain, Anhui Province, China. Results showed that at 20℃ mass loss of leaf litter driven by microbial decomposers was higher in broadleaf forest than that in coniferous forest, whereas the difference in mass loss of leaf litter was not significant at 30℃. The temperature increase did not affect the mass loss of leaf litter for coniferous forest treatment, but significantly reduced the decomposition rate for broadleaf forest treatment. The functional decomposers of microorganism in broadleaf forest produced a higher lignin decomposition rate at 20℃, compared to that in coniferous forest, but the difference in lignin decomposition was not found between two forest types at 30℃. Improved temperature increased the lignin decomposition for both broadleaf and coniferous forest. Additionally, the functional group of microorganism from broadleaf forest showed marginally higher carbohydrate loss than that from coniferous forest at both temperatures. Temperature increase reduced the carbohydrate decomposition for broadleaf forest, while only a little reduce was found for coniferous forest. Remarkable differences occurred in responses between most enzymes （Phenoloxidase, peroxidase, !5-glucosidase and endocellulase） and decomposition rate of leaf litter to forest type and temperature, although there exist strong relationships between measured enzyme activities and decomposition rate in most cases. The reason is that more than one enzyme contribute to the mass loss of leaf litter and organic chemical components. In conclusion, at a community scale the coniferous and broadleaf forests differed in their temperature-decomposition relationships.

古田山国家级自然保护区甜槠林优势种群生态位

采用样方法进行不同资源位群落调查,利用生态位宽度、生态位相似性比例和生态位重叠公式测试了古田山国家自然保护区甜槠林14个优势种群[甜槠(Castanopsis eyrei)、木荷(Schima superba)、马银花(Rhododendron ovatum)、檵木(Loropetalum chinensis)、麂角杜鹃(Rhododendron latoucheae)、虎皮楠(Daphniphyllum macropodum)、马尾松(Pinus massoniana)、青冈(Cyclobalanopsis glauca)、乌饭树(Vaccinium bracteatum)、石栎(Lithocarpus glaber)、赤楠(Syzygium buxifolium)、石楠(Photinia serrulata)、栲树(Castanopsis fargesii)、钩栗(Castanopsis tibetana)]的生态位。结果表明:甜槠和木荷的生态位宽度较大,其Bi、Ba分别为0.8703、0.8528和0.8446、0.7824;而石楠、栲树和钩栗的生态位宽度较小,其Bi、Ba分别为0.2956、0.1359,0.2953、0.1356和0.2684、0.1064。生态位宽度较大的物种之间的生态相似性比例较大,如甜槠与木荷、甜槠与马银花、木荷与马银花的生态相似性比例分别为0.7630、0.7252和0.6452;对生境需求有较大相似性的生态位宽度不同的物种其生态位相似比例也会较高,如木荷与马尾松生态位相似比为0.6866。生态位宽度较大的树种间生态位重叠较大,如甜槠、木荷、马银花等。甜槠林中生态位重叠值大于0.1的有39对,仅占21.4%,生态位重叠值不大,表明甜槠林中因利用相同的资源位而产生的种间竞争并不激烈,是一个稳定的森林群落。

红锥嫩枝扦插生根过程中营养物质的变化

从一年生红锥（Castanopsis hystix）母株上剪取嫩枝作插穗,研究其扦插生根过程中营养物质含量的变化。结果表明,红锥嫩枝扦插生根过程中插穗基部的可溶性糖含量呈升高-降低的变化趋势,淀粉含量呈降低-升高-降低的的变化趋势,蛋白质含量呈缓慢升高-急剧降低-急剧升高的变化趋势,氮素含量呈缓慢上升的变化趋势,C/N呈下降-上升-下降的变化趋势。红锥插穗扦插后0~18 d是生根的重要时期,愈伤组织和不定根原始体的诱导都在这一阶段进行,叶面喷施适量的蔗糖可促进根原始体的形成。

凋落物及播种时间对高山栲和滇青冈种子萌发的影响

高山栲(Castanopsis delavayi)和滇青冈(Cyclobalanopsis glaucoides)种子播种后,分别覆盖约2 cm厚的高山栲、滇青冈、元江栲(Castanopsis orthacantha)和云南油杉(Keteleeria evelyniana)枯枝落叶,以覆盖红壤为对照,研究了森林凋落物及播种时间对半湿润常绿阔叶林建群种高山栲和滇青冈种子萌发的影响。结果表明:不同森林凋落物对高山栲和滇青冈种子萌发率的影响趋势一致,其中对照处理的红壤最高(29.1%和66.9%),其次是云南油杉枯枝落叶(28.2%和57.1%)、高山栲枯枝落叶(25.1%和53.3%)和滇青冈枯枝落叶(20.7%和51.6%),最低的是元江栲枯枝落叶(18.7%和44.0%)。播种时间对高山栲和滇青冈种子萌发率的影响差异极显著,其中12月份播种的种子萌发率最高,分别为58.0%和68.7%;随着播种时间的后移,其萌发率逐渐降低。高山栲种子在次年5月中旬开始萌发,休眠期为6个月,而滇青冈种子的休眠期约5个月,于次年4月中旬开始萌发;两种植物的萌发期大致在6个月左右,且萌发高峰期基本一致,即出现在次年6月份。

大叶栎地理种源生长差异及优良种源选择

对广西南宁的16个大叶栎[Castanopsis fissa(Champ.)Rehd.et Wils.]种源6年生林分的生长性状及遗传变异进行了研究,结果表明,种源间的保存率、树高、胸径、材积、干形存在显著或极显著差异;树高、胸径、材积、干形的种源遗传力均在0.5以上,说明种源间具有良好的选择潜力;树高、胸径、材积之间存在显著或极显著的正向相关关系,树高与干形显著负相关,种源的生长性状与原产地的地理位置及气候条件相关关系不大;运用多性状综合评定法选出了广西苍梧大叶栎、广西平果大叶栎、湖南通道大叶栎为优良种源;3个优良种源的平均树高遗传增益为2.88%,平均胸径遗传增益为12.12%,平均材积遗传增益为28.73%,平均干形遗传增益为5.25%。

哀牢山北段中山湿性常绿阔叶林的温度效应

引言温度或热量条件是森林生长发育重要的环境因子之一。森林对气温又有显著影响,特别是森林内的温度再分配又有其独特的温度特征。云南哀牢山北段自然保护区的景东县徐家坝生态工作站(24°32′N,101°01′E,海拔2450米)为开展“人类活动对森林生态系统的影响”的研究课题,在中山湿性常绿阔叶林(主要优势树种有木果石栎Lithocarpus xylocarpus、景东石栎L.chintungensis、腾冲栲Castanopsis

安徽查湾甜槠林不同大小林隙光因子对比分析

以安徽查湾自然保护区甜槠(Castanopsis eyrei)林为研究对象,分析不同大小林隙光因子变化情况。结果表明:不同大小林隙及非林隙林分内光照强度日变化呈单峰型,光照的峰值出现在11:00~13:00。在整个生长季中,光照和气温均表现为:大林隙>中林隙>小林隙>非林隙。不同大小林隙内光照由林隙中心区向林下逐渐递减,于近心区处减幅最大。