论山毛榉科植物的系统发育

本文运用分支分类学方法,对山毛榉科植物进行了系统发育的分析。山毛榉科作为单元发生群包括柯属、锥属、粟属、三棱栎属、水青冈属和栎属。桦木科和南山毛榉属被选择作为外类群。对大量的性状进行评估之后,选择了25对性状作为建立数据矩阵的基本资料。性状极化以外类群比较为主,同时也采用了化石证据和通行的形态演化的基本原则。数据矩阵由7个分类群、2个外类群和25个性状组成。采用最大同步法、演化极端结合法和综合分析法对该数据矩阵进行了分析。在得到的3个树状分支图中按照最简约的原则,选出演化长度最短的谱系分支图作为本文讨论山毛榉科属间的系统演化关系的基础。关于山毛榉科植物的系统发育,作者的观点如下：(A)现存的山毛榉科的6个属形成了4条平行进化的分支路线,它们分别被处理作4个亚科,即：栗亚科,三棱栎亚科,水青冈亚科和栎亚科;(B)平行进化是山毛榉科植物系统发育过程中的主要形式。生殖过程中的一些特征,如：果实第二年成熟,胚珠通常败育等,是影响山毛榉科植物属间基因交流的主要原因。在现存的山毛榉科植物中,柯属是最原始的类群。三棱栎属和锥属的起源也较早,而栗属、水青冈属和栎属是特化的类群。     

广西锥属植物一新种

<正> 龙州锥 (新种) 图版1 本种与淋漓锥近缘,但本种的叶片两面无毛且同色,叶缘有锯齿状裂齿,有时为钝裂齿,网状叶脉纤细而明显,果序较短,有果较少数,壳斗及坚果较大,壳斗的鳞片被毛,覆瓦状松弛排列,可作区别特征。 乔木,高5—8米,树干胸径8—15厘米,树皮灰棕色,当年生枝浑圆,粗壮,无毛,干后近暗棕色,密生淡黄色、细圆点状皮孔;新生芽阔卵形,顶端钝,长及宽均约3毫米,芽鳞无毛或边缘有稀疏短毛。叶硬报质,卵形,椭圆形或披针形,稀倒卵形,连叶柄长8—     

湘中丘陵区石栎群落研究

以湘中丘陵区石栎 (L ithocarp us glaber)群落为调查研究对象 ,分析了群落的特征 ,定量计测了乔木层主要树种的生态位宽度和重叠值。结果表明 ,石栎群落垂直结构较为复杂 ,可分为乔木层、灌木层、草本层 ,亦有少量的层间植物。群落的优势种较明显 ,乔木层的物种多样性指数较高。主要树种生态位宽度值大小顺序为 :石栎、苦槠、木荷、白栎、拟赤杨、南酸枣和柏木。在生态位重叠值中 ,以优势种石栎与白栎、柏木、枫香、樟树、拟赤杨、木荷、南酸枣、苦槠、秃瓣杜英重叠值较大 ,枫香与苦槠的重叠值最小 ,石栎与马尾松、君迁子属中等重叠     

壳斗科木材识别和分类

从106种壳斗科木材构造特征.作为本科木材识别和分类依据,概括于下: 散孔材,管孔细,单个密布,在生长轮末端一狭带无管孔,宽射线为多列射线,较狭而数较多为水青冈属。辐射孔材,管孔成串径列,宽射线聚合型,在横面反光弱为主,分布不均,促使材身槽棱不整齐,槽底平而宽长的为稠属。辐射孔材,管孔成串径、斜列为主,宽射线聚合型(常见)和栎型,在横面反光强,分布均匀,促使材身槽棱整齐,槽底尖而分隔为青冈属。半环孔材或环孔材,早材管孔沿生长轮不连续排列,在肉眼下可见至明显,晚材管孔成串径列,弯曲或火焰状,宽射线聚合型,常数少且几条聚近分布,大部分树种无宽射线的为锥属。环孔材,早材管孔沿生长轮连续排列,肉眼下明显,侵填体丰富,晚材管孔成串径列,弯曲或火焰状,宽射线栎型为栎属。环孔材,早材管孔沿生长轮连续排列,肉眼下明显,具侵填体,晚材管孔成串径列,弯曲或火焰状,射线细而肉眼下不见为栗属。 各属共同特征,薄壁组织离管带状,似环管(实际为环管管胞),生长轮不同程度波状。     

Pollen AnalysiS and Paleoenvironment Study of Late Pleistocene in Daganba,Guizhou Province

In this paper, the division of the two pollen zones is discussed based on the results of pollen and spores analysis and 14C dating in the Daganba area, Zhijin County, central Guizhou Province. Zone Ⅰ represents a forest of mixed evergreen-deciduous broad-leaved trees closed subtropic mountain and dominated by Fagus, Quercus, Cyclobalanopsis, Carpinus and Castanea (Castanopsis, Lithocarpus) together with Pinus, Tsuga and Abies till 23000 yr B.P. It stands for the Dali interstadial climate, cool and moist. Zone Ⅱ vegetation adopted dry climate. During the time from 23000 yr B. P. to the fullglacial period the forest cowered and the fern extended. The pioneer trees such as Pinus, Betula began to grow towards the end of the dry phase. The genus Fagus is of great importance in studing ecology and geography of the flora. The retirement and growth of Fagus forest reveals the paleoenvironment changes.     

The Pollen Morphology in Relation to the Taxonomy and Phylogeny of Fagaceae

The present paper deals with the pollen morphology of 103 species belonging to sixgenera-Castanea, Castanopsis, Lithocarpus, Quercus, Fagus and Trigonobalanus in threesubfamilies-Castaneoideae, Quercoideae and Fagoideae. All pollen grains were examinedunder light microscope and scanning electron microscope, and those of some species were ex-amined under transmission electron microscope. The results may be summarised as follows:1. Pollen morphology of Fagaceae, seems to support division of the family into threesubfamilies. Fagoideae, Castaneoideae and Quercoideae.2. Four types of pollen grains are recognized in Fagaceae:1) Fagus-type (representative genus: Fagus): pollen granis are oblate-sphaeroidal,(31.5-39.9) x (35.7 46.2) μm in size, 3(-4)-colporate, peritreme or goniotreme, granulate-ornate under LM., granulate or verrucate under SEM.2) Trigonobalanus-type (T. doichangensis): pollen grains are suboblate-sphaeroidal,(23.1-29.4) ×(25.2-29.4) μm in size, 3-colporate, goniotreme, obscurely granulate-ornateunder LM, densely granulate or verrucate under SEM.3) Quercus-type (Quercus): pollen grains are subspheroidal-subprolate, (21-44.3)× (16.8-39.9) μm in size. 3-colporoidate (-3-colpate), peritreme, crassgranulate or finely-gra-nulate under LM, tuberculate verrucate or spinate under SEM.4) Castanea-type (including Castanea, Castanopsis, Lithocarpus): Pollen grains areprolate-supraprolate, (14.7-23.1)×(10.5-16.8)μm in size; 3-colporate, peritreme, obscu-rely ornate or subpsilate, under LM, rugulose, striate-rugulate or crass-striate under SEM.3. Pollen grains of Cyclobalanopsis age very similar to those of Quercus, and there-fore we support the treatment of Cyclobalanopsis as a subgenus of Quercus.4. On the basis of shape, type of aperture and exine structure, pollen of Trigonobalanusis distinguishable from those of the other genera in Fagaceae and it may be a new type of Fagaceae;5. On the basis of pollen morphology, morphological characters and geological stratification a scheme of phylogeny of Fagaceae is here presented.     

中国亚热带常绿阔叶林优势种及常见种的水热分布类群

 利用目前国际上比较常用的植被—气候相关分析的气候指标,如Kira的温暖指数和寒冷指数,徐文铎的湿润指数,Penman的可能蒸散和干燥度指标,Thornthwaite的潜在可能蒸散和水分指数,Holdridge生命地带分类系统指标以及气温和降水等单一气候因子,综合对中国亚热带常绿阔叶林优势种及常见种进行TWINSPAN分类和DCA排序,可将植物种分为8个水热分布类群,较好地反映出优势种及常见种沿热量和水分梯度的分布格局。并总结了这8个水热分布类群的气候指标范围。这8个类群是：Ⅰ高温湿润型,Ⅱ高中温湿润型,Ⅲ低中温湿润型,Ⅳ高低温中湿型,Ⅴ低低温中湿型,Ⅵ低温半湿润型,Ⅶ高低温低湿型,Ⅷ低低温低湿型     

Karyotype Analysis in Lycoris rosea Traub et Moldenke

The present paper embodies the results of a karyotypic analysis for the species Lycoris rosea Traub et Moldenke. The voucher specimen, J. Z. Lin 004 is preserved in the Herbarium of Hanchow Botanical Garden. The chromosome number in root tip cells is found for the first time to be 22, and the karyotype is shown to be an asymmetrical one with rod-shaped chromosomes. A photomicrograph, the karyotype and the idiogram are shown in Figs. 1-2. According to Levan et aL.^[5], the karyotype formula of the species is 2n=22=22t. But based on the classification presented by Bose and Flory^[1], the karyotype formula should be expressed as 2n=22 =C22, and the chromosomes are all with subterminal constrictions. If regarding 11 as the basic number and centric fusion as the major tendency of karyotype evolution as proposed by Inariyama^[2], Stebbins^[6], and Jones^[3,4] in particular, L. rosea would be considered as one of the most primitive species in Lycoris from point of view of karyotype evolution. Reciprocal translocations and centric fusions would give rise to V-shaped chromosomes. Consequently, the successive decrease in chromosome number may have taken place in the speciation of the genus under discussion. Yet further evidence seems ne-cessary for the verification of the speculation.     

天童几种常绿阔叶林优势种在砍伐后萌枝更新的初步研究

对以萌生方式形成的木荷、石栎、苦槠、栲树、米槠植株的根桩和萌枝状况进行了调查及测量。结果显示各种类萌枝数的大小顺序是:木荷>苦槠>石栎>米槠>栲树;结合萌枝状况可以推断萌枝能力的大小顺序应该是:木荷>苦槠>石栎>栲树>米槠。砍伐对木荷、石栎、苦槠、栲树、米槠萌芽更新都会造成影响,对栲树、米槠影响更大,而对木荷、石栎、苦槠影响较小。从植物萌生角度来说,这是形成研究地区大面积的以木荷、石栎、苦槠为优势种组成的次生灌丛的主要原因。     

壳斗科的地质历史及其系统学和植物地理学意义

在收集整理现有壳斗科化石资料的基础上,讨论了壳斗科及其各属的起源时间、地史分布和地史 演替过程以及这些化石资料在系统学和植物地理学上的意义。白垩纪尚无壳斗科可靠的大化石记录, 微化石需要进一步研究才能确定亲缘关系以及古新世壳斗科已经分化出两个类群。从以上这些事实推 论壳斗科起源于白垩纪晚期,而壳斗科现代各属出现的时间应不晚于古新世。最早发现的壳斗科化石和现代栗亚科和水青冈亚科在形态结构上非常相似,这一事实表明,壳斗科分为两个亚科的观点更接近客观事实。在水青冈亚科中,三棱栎类的化石最早出现;在栎属中,青冈亚属更接近祖先类群;在地史中全缘栎类较具齿栎类出现早,粗齿的落叶栎类出现最晚。三棱栎属、栲属和石栎属的化石在老第三纪出现于北美和欧洲的事实说明,北美、欧洲和东亚在老第三纪时有一个相通的壳斗科植物区系。南美的三棱栎是通过北美进入南美的。中国横断山、欧洲地中海沿岸和北美西北部有一类形态特征相似、亲缘关系相近的硬叶栎类,它们之间有相同的地质演替历史,它们现代分布边界可能就是古地中海的边界。美洲的栎类有两个来源,常绿硬叶栎类是通过古地中海沿岸而经北美-欧洲陆桥到达的,落叶栎类则是在中新世以后通过白令海峡到达的。     

Chemotaxonomic Relationship Between Murraya and Merrillia (Rutaceae)

Swingle^[14-15] divided Aurantioideac into two tribes, one of which, Clausereae was further divided into three subtribes, namely, Micromelinae, Clauseninae and Merrilliinae. Mic romelinae and Merrilliinae each have one genus, whereas Clauseninae has three genera. Morphologically, the Clauseneae is a natural tribe, the five genera are related in a linear sequence, starting with Micromelum as the most primitive and progressing in sequence to Glycosmis, Clausena, Murraya and Merrillia. Chemical studies also support this linear relationship, as revealed by the degree of oxygenation and complexity of the 3-methyl carbazole alkaloids, from CH₃ and C1₃ in Glycosmis to CHO and C₁₈ in Clausena and COOH and C₂₃ in Murraya^[20-21]. Distribution of flavonoids also indicates the progression from Clauseninae to Merrilliinae^[18-19]. Extensive work has been conducted on the chemistry and taxonomy of the genus Murraya ^{[1,5,7-13,16]}, and the data from these studies clearly indicate the presence of two distinct groups. Based on a combination of morphological and chemical differences, we agreed with Tanaka^[16-17] in dividing Murraya into two sections, i.e. section Murraya and section Bergera^[1]. However, our previous study^[1] has not touched on the relationship between the two sections. Tanaka^[16-17] placed section Bergera before section Murraya, and indicated that the former is close to Micromelum and the latter to Merrillia. Swingle^[14-15], on the other hand, put taxa of section Murraya ahead of those of section Bergera, presumably suggesting that plants of section Murraya are more primitive than those of section Bergera, this arrangement was followed by Huang^[2-3]. The two conflicting viewpoints would have direct bearings on the interpretation of the trends of biogenesis of prenylated indole and carbazole alkaloids, as well as on the weighing of the relative advancement of the morphological characters within the genus, such as in the assignment of indices of divergence and in the construction of Wagner Divergence Diagrams. Without more objective criteria, we find it difficult to select one of the two systems. In order to determine the relationship between the two sections of Murraya, we decided to study plants of related genera, with the hope that the chemical data may shed light on the problem. A plant that attracted our attention is Merrillia caloxylon (Ridley) Swingle. So far, only eupatorin and a few other flavonoids have been reported from the fruit of this species^[4,6]. Although Me. caloxylon belongs to Merrilliinae, a subtribe next to Clauseninae, Tanaka^[16-17] believes that it is close to Murraya section Murraya. Swingle^[15], also suggested that this species might have developed from the same stock that gave rise to Mu. paniculata. If their interpretations were accurate, we would expect that Me. caloxylon would also contain yuehchukene and 8-prenylated coumarins. The presence of the antiimplantation agent would not only open up a new source of the compound but also help us judge the relationship between the two sections of Murraya. It is in this context that we studied the chemical composition of Me. caloxylon. Indeed, root and stem bark of Me. caloxylon were found to contain the antiimplantation indole alkaloid yuehchukene (1), and the 8-prenylated coumarins sibiricin (II) and phebalosin (III), as well as 3-(3-methy1-buta-1,3-diene) indole (IV) and eupatorin (V.) Details on the chemical profiles are reported in another paper. Through this exercise, we have confirmed the close relationship between Merrilliinae and Murraya section Murraya, plants of both taxa contain yuehchukene and 8-prenylated coumarins, but no carbazole alkaloid. Root and stem bark of Me. caloxylon, like those of plants of section Murraya, are strawcolored to pale whitish. Its leaves also bear wings along the rachis an in Mu. alata, and the seeds are also villous. However, Me. caloxylon has long trumpetshaped flowers 55-60 mm long, much larger than those found in other rutaceous plants. Its fruit is ob long, up to 11 cm long and 8 cm across, bearing a thick and warty pericarp, exuding a very stick mucilage when cut, and containing numerous seeds (>30). The plant was known to exist in the Malay Peninsula and north Sumatra^[15], but, according to David Jones (per. comm.) of the University of Malaya, is now only available in cultivation in Malaysia and Singapore, a limitation to any further exploitation as an additional source of yuehchukene. Besides confirming the close relationship between Merrillia and section Murraya, we may also conclude that section Bergera is close to Glycosmis and Clausena, since they are known to contain carbazole alkaloids but no yuehchukene. Accordingly, we find Tanaka’s arrangement more acceptable: plants of section Bergera are more primitive than those of section Murraya, the former is close to Clausena whereas the latter (notably Mu. alata) to Merrillia. The relationship among the gonera with in Clauseneae may be illustrated as follow: Micromelum→ Glycosmis→Clausena→Murraya sect. Bergera→Murraya sect. Murraya→Marrillia. Accordingly, we may decide that the following character states are more primitive among plants of Murraya and Merrillia: root and stem bark dark brown, leaf rachis wingless, flower small, fruit purple-black with few seeds, and seed coat glabrous. In contrast, strawcolored or pale whitish bark, winged leaf rachis, large flower, red or yellow fruit with many seeds and villous seed coat can be regarded as more advanced characters. Acknowledgments Partial support was received from the World Health Organization Special Programme on Human Reproduction and the Kevin Hsu Research Fund (to YCK) and Commonwealth Science Council (to PPHB). The staff of the Singapore Botanic Gardens and the Forest Research Institute of Malaysia are thanked for their assistance in collecting plantmaterial.     

Fossils of the Fagaceae and their implications in systematics and biogeography

The fossil history of the Fagaceae from China and its systematic and biogeographic implications are discussed based on revisionary studies of the fossil records. No creditable macrofossil record of the Fagaceae exists in the Cretaceous deposits and all the Cretaceous microfossil reports remain equivocal and require further study. The Paleocene fossils show the appearance and diversification of the two groups corresponding to the subfamilies Fagoideae and Castaneoideae sensu Nixon. By the Eocene, all modern genera had been present. The oldest fagaceous fossils represent subfamily Fagoideae with affinities to the extant genus Trigonobalanus. The leaf fossil genus Berryophyllum, with affinities to Quercus subg. Cyclobalanopsis, has been documented by the early Eocene and might have occurred earlier than other fossils assignable to Quercus. The appearance of evergreen sclerophyllous Ouercus with entire leaves might have occurred earlier than those with toothed leaves. Deciduous, urticoid-leaved oak fossils (Quercus subg. Quercus sect. Quercus) had not appeared until the Miocene. Fossil equivalents of Trigonobalanus, Castanopsis and Lithocarpus had occurred in Europe and North America by the early Tertiary, suggesting that continuous distributions were achieved via the northern hemisphere land bridges. Three groups of evergreen sclerophyllous oaks of apparent close phylogenetic relationships occurred in the Hengduan mountains, the Mediterranean area and northwestern North America. Their fossil forms have become dominant elements of those vegetation zones since the Miocene. A shared fossil history indicates a possible biogeographic boundary formed by the ancient Mediterranean. The evidence suggests that the oaks might arrive in North America during two distinct geologic periods: evergreen sclerophyllous entire-leaved oaks appeared by the Early Tertiary, whereas thedeciduous oaks with urticoid leaves appeared in the Late Tertiary.     

Karyotype Analysis of Reineckia carnea (Andr.) Kunth (Liliaceae)

Karyotype analysis for the species Reineckia carnea (Andr.) Kunth of the monotypic genus Reineckia Kunth is given for the first time. The number of chromosomes in root-tip cell was found to be 38, which is in accord with those reported by most of the previous authors^{[5,7,8,9,11,12,]}. The somatic complement shows a slight variation in size, i.e., the 2, 3, 5, 6, 7th pairs of the chromosomes have submedian constrictions, while the other pairs have median centromeres. The karyotype is therefore a rather symmetrical one, and according to the chromosomal terminology defined by Levan et al^[4], the karyotype formula of the species is 2n=38=28 m+10 sm. In spite of the presence of two nucleoli in the telophase as observed by the authors and Noguchi^[8] as well, the two corresponding Sat-chromosomes have not been found. Photomicrograph of the chromosome complement and idiogram are given in Fig. 1 and 2 respectively.     

Cytological Investigation of Taiwania flousiana Gaussen (Taxodiaceae)

The present paper deals with the cytological investigation of Taiwania flousiana Gaussen. The somatic chromosomes in root-tip cells of the plant are found to be 2n=22 for the first time, all with median and submedian constrictions. According to the terminology defined by Levan et al.^[11], the karyotype formula is K(2n)=16m+6sm, which belongs to “2B” of Stebbins'^[16,17] karyotypic symmetry and is generally regarded as a relatively primitive one. The species' chromosome complement is 2n=22=4L+6M₂+8M₁+4s according to the standard defined by Kuo et al.^[10] based on relative length. The nucleolus number in resting root-tip cells of T. flousiana is found to be 1-5 (Table 3). The percentage of cells with two nucleoli is 77.6%, and those with five nucleoli, the highest number ever found by me, is only 1.6%. A few cells with many micronuclei are found in this species for the first time (Plate 1, 1). Although T. flousiana and T. cryptomerioider have the same “2B” type of karyotypic symmetry, the differences in the arm ratio and the index of the karyotypic asymmetry (Table 2) show that the karyotype of the former is less symmetrical than that of the latter, so the former may be a little more advanced than the latter. The basic karyotype (2B) of Taiwania is more related to that of Cunninghamia (1B)^[3] than to that (1A) of Metasequoia^[5], Glyptostrobus^[4] and Cryptomeria^[3]. Wang et al.^[1], have reached the similar conclusion from the embryological study.     

Association classification of a 30 hm2 dynamics plot in the monsoon broad-leaved evergreen forest in Pu’er,Yunnan, China

季风常绿阔叶林是我国南亚热带典型的地带性植被, 建立森林动态监测样地是研究生物多样性维持和群落构建机制的重要平台。该文以普洱30 hm ²森林动态监测样地为研究对象, 采用多元回归树、重要值、主成分分析与指示种相结合的方法对样地内750个样方进行群丛数量分类, 以获取季风常绿阔叶林森林植被群丛类型。结果表明: 森林动态监测样地共发现木本植物271种, 隶属于78科178属, 群落类型为短刺锥(Castanopsis echidnocarpa)群系, 可划分4个群丛类型, 分别是珍珠花+毛银柴-短刺锥+泥柯群丛(Lyonia ovalifolia + Aporosa villosa - Castanopsis echidnocarpa + Lithocarpus fenestratus Association)、云南瘿椒树+耳叶柯-短刺锥+西南木荷群丛(Tapiscia yunnanensis + Lithocarpus grandifolius - Castanopsis echidnocarpa + Schima wallichii Association)、大果杜英+黄药大头茶-短刺锥+西南木荷群丛(Elaeocarpus sikkimensis + Polyspora chrysandra - Castanopsis echidnocarpa + Schima wallichii Association)、西桦+尼泊尔桤木-短刺锥+枹丝锥群丛(Betula alnoides + Alnus nepalensis - Castanopsis echidnocarpa + Castanopsis calathiformis Association)。群丛间物种分布存在较多过渡重叠, 指示物种是区分群丛类型的主要依据, 海拔与坡向对群丛分类有较大的影响, 坡度对群丛分类影响较小。     

西藏壳斗科订正

在野外观察和前人工作的基础上,对西藏壳斗科植物进行了详细的订正,描述了１个新种,报道１个中国新记录种,４个西藏新记录种,归并１１种和２变种,排除无标本记录的２种。确认西藏壳斗科植物共３属３２种,２变种。     

Chromosome Numbers in Leonurus japonicus Houtt. (Labiatae)

Leonurus japonicus Houtt. [L. heterophyllus Sweet, L. artemisia (Lour.) S. Y. Hu] is one of the most important traditional Chinese medicines used as a remedy for gynaecological disease since ancient times. A cytological investigation on the species was carried out and the materials for chromosomal examination were collected from 26 localities in 20 provinoes and autonomous regions of this country. The number of chromosomes in root tip cell of the species was found to be 20 on the whole (Tab. 1:1), agreeing with those reported by Ma and al.^[2] and probably by Chuang and al.^[3] as well. The genus Leonurus L. is variable in its chromosomes with an aneuploidy of x=9, 10 and 12. The present authors would propose that the primitive basic number of chromosome in the genus is 9, and thus both 10 and 12 are derived, for: (1) among the 9 species (including 1 subspecies) heretofore cytologically examined, x=9 occurring in 66.7%, x=10 occurring in 22.2%, while x=12 occurring only in 11.1%; (2) in generaclosely related to the genus under consideration, such as Panzeria, Galeobdolon and Lamium x=9 being the sole basic number. But L. japonicus exhibits a mixoploidy of 2n=20 (occurring at the rate of 53.30% of the total amount of cells examined), 2n=18 (30.70%), and 2n=16 (15.99%) in our work. (Table 1). Since the original basic number of chromosome of the genus is 9 as proposed above, 2n= 20 would be considered as a derived one and the occurrence of 2n=18 probably suggests an early evolutionary trend of 2n=18→20 of the pecies in question.     

演替研究在常绿阔叶林抚育和恢复上的应用

以浙江天童国家森林公园常绿阔叶林动态过程为例,比较研究了常绿阔叶林演替系列主要树种白栎（Quercus fabri）、马尾松（Pinus massoniana）、苦槠（Castanopsis sclerophylla）、石栎（Lithocarpus glaber）、木荷（Schima superba）和栲树（C.fargesii）的群落生态学特征、种群生态学特征和生理生态学特性。阐明了常绿阔叶林演替系列间的相互更替过程;探讨了主要优势种群的植株结构及其更新能力的演变规律;揭示了演替系列群落主要优势种相互更替的原因。     

我国特有植物银杉的资源、分布及其环境

我国银杉自1955年发现以来,陆续发现了它的新分布,至今已知在四省、区7个分布区的30多个分布点上,自然生长着银杉3200余株。它们是:广西花坪林区(越城岭南部)6个点有银杉1040抹,其中高5米以上的68株,1～5米的49株,1米以下的923株,最高21.1米,最大胸径83厘米;广西大瑶山4个点有银杉143株,其中高10米以上的94株,1～3米的3株,1米以下的46株,最高30米,最大胸径79.2厘米;湖南罗汉洞(越城岭北部)2个点有银杉58株,5米以上的有45株,最高18米,最大胸径43厘米;湖南罗霄山脉八面山有银杉707株,高1米以上的334株,最高24米,最大胸径46厘米;四川南川金佛山(大娄山东段北部)6个点有银杉527株,其中成年树400余株,最高17米,最大胸径50厘米;百枝山有银杉52株,最高8米,最大胸径27厘米;贵州道真沙河林区(大娄山东段南部)3处12个点有银杉729株,其中高5米以上的105株,2～5米的209株,1～2米的111株,1米以下的304株,最高18.8米,最大胸径48厘米;贵州桐梓白菁有银杉10株,高4～5米的2株,1～3米的6株,1米以下的2株。 银杉分布区范围自北纬24°5′～29°13′14″,东经107°10′～113°40′。其垂直分布自海拔940～1840米,金佛山银杉分布最高,为1600～1840米;罗汉洞银杉分布最低,为940～1060米。分布区内,年均温8.2°～17℃,绝对最低温