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1.
鄂西神农架地区的植被和植物区系 总被引:1,自引:0,他引:1
Shennungia is generally known as “The highest mountain in Central China”. It is
situated at latitude 31°342'N., longitude 110°35'E. in western Hupeh.
The area explored is deeply cut in all sides by five V-shaped valleys, giving the
landscape a steep topography. Its summit is about 3105 meters above the sea level, and
the relative altitude is from 1000-2000 meters.
The climate of the region is warm temperate. The differences of humidity-warmth
condition between the eastern and the western flanks are quite marked.
In western Hupeh and the adjacent area of Szechuan the rugged topography still
preserves some tracts of natural forests at higher elevations. Our vegetational survey
is confined to localities above 1500 meters. The collection of plant samples of the flora
is extended to the whole mountain from the foothill to the peak. The present article
deals with only a part of the results of our survey.
1. The vertical vegetation belts of Mt. Shennungia and relationships with other
regions: The vegetation belts on the eastern and the western flanks of the mountain
are shown in diagram 2 and 3. The comparison of the vertical vegetation zones of the
Mt. Shennungia with those of the Yülungshan in N. W. Yunnan and the eastern
Himalaya to the west and with those of Hwangshan and Central Japan to the east
is shown in table 4, It shows that the plant communities of the Mt. Shennungia are of
temperate nature, and they are more closely related to those of Hwangshan in S.
Anhwei and of Central Japan than to the eastern Himalaya.
2. Floristic composition: The generic ranges of flowering plant are relatively
distinct and stable. Various distributional patterns of genera are analysized.
1) Statistics of the genera in various distributional patterns: The total number
of genera of flowering plants in this region are 762, belonging to the following four
categories. A) tropical genera 239 (31.3%), B) temperate genera 416 (54.7%), C)
endemic genera 47 (6%), and D) comsmopolitan genera 61 (8%).
2) Endemic genera: An examination of the composition of the flora in western
Hupeh reveals that 47 endemic Chinese genera occur in this mountain of which 24 are
monotypic genera, 20 oligotypic and 2 multitypic as shown in Table 4. The arborescent
genera are nearly all deciduous. They are of temperate nature.
3) Temperate genera: There are 416 genera in wastern Hupeh. They are
subdivides into the following three groups according to their distributional patterns:
A) The north temperate genera: There are 159 genera belonging to 62 families in
western Hupeh. B) Eastern Asian genera: There are 117 genera belonging to 69
families in western Hupeh. Among them 22 are common to the western Szechuan,
adjacent regions of Yunnan and the Eastern Himalaya. The remaining 95 genera are
commom to both eastern China and Japan. C) The Eastern Asian-eastern North-
American genera: Of the total 762 genera known in western Hupeh, 64 are disjunc-
tively distributed in both eastern Asia and eastern North-America.
4) The tropical genera: Of the 762 genera of the flowering plant of western
Hupeh, 239 (31%) are of tropical nature.
Finally, our survey shows: 1. Many of the primitive temperate genera and ende-
mic relicts concentrate in western Hupeh and the adjacent region of Szechuan indica-
ting that it might be one of refuges of tertiary flora. Moreover, it might also be one
of the most important regions of differentiation, development and distribution of tem-
perature flora. 2. The vegetation of this region is not only of temperate nature, but
also of a transitional nature. 3. According to an analysis of the flora and a compari-
son of the vertical distribution of the vegetation of Yülungshan and Eastern Himalaya
to the west with Hwangshan and Central Japan to the east, the floristic affinity of
western Hupeh is more closely related to eastern China and Central Japan rather than
to the Eastern Himalaya, and phytogeographically this region is intermediate between
the Sino-Himalayan and the Sino-Japanese patterns. However, the problem of phyto-
geography of western Hupeh and the adjacent region of Szechuan is a complicated
one requiring further study.
相似文献
2.
Xizang (Tibet) is rich in Leguminosae flora, comprising 41 genera and 254 species
so far known, exclusive of the commonly cultivated taxa (including 11 genera and 16
species). There are 4 endemic genera (with 8 species), 10 temperate genera (with 175
species) and 19 tropical genera (with 46 species) as well as the representatives of those
genera whose distribution centers are in East Asia-North America, Mediterranean
and Central Asia.
1. There are altogether 4 endemic genera of Leguminosae in this region. Accord-
ing to their morphological characters, systematic position and geographical distribution,
it would appear that Salweenia and Piptanthus are Tertiary paleo-endemics, while
Straceya and Cochlianths are neo-endemics. Salweenia and Piptanthus may be some
of more primitive members in the subfamily Papilionasae and their allies are largely
distributed in the southern Hemisphere. The other two genera might have been derived
from the northern temperate genus Hedysarum and the East Asian-North American
genus Apios respectively, because of their morphological resemblance. They probably
came into existanc during the uplifting of the Himalayas.
2. An analysis of temperate genera
There are twelve temperate genera of Leguminosae in the region, of which the
more important elements in composition of flora, is Astragalus, Oxytropis and Cara-
gana.
Astragalus is a cosmopolitan genus comprising 2000 species, with its center
distribution in Central Asia. 250 species, are from China so far known, in alpine zone of
Southwest and Northwest, with 70 species extending farther to the Himalayas and
Xizang Plateau.
Among them, there are 7 species (10%) common to Central Asia, 12 species (15.7%)
to Southwest China and 40 species (60%) are endemic, it indicates that the differentia-
tion of the species of the genus in the region is very active, especially in the subgenus
Pogonophace with beards in stigma. 27 species amounting to 78.5% of the total species of
the subgenus, are distributed in this region. The species in the region mainly occur in
alpine zone between altitude of 3500—300 m. above sea-level. They have developed into
a member of representative of arid and cold alpine regions.
The endemic species of Astragalus in Xizang might be formed by specialization of
the alien and native elements. It will be proved by a series of horizontal and vertical vicarism of endemic species. For example, Astragalus bomiensis and A. englerianus are
horizontal and vertical vicarism species, the former being distributed in southeast part
of Xizang and the latter in Yunnan; also A. arnoldii and A. chomutovii, the former
being an endemic on Xizang Plateau and latter in Central Asia.
The genus Oxytropis comprises 300 species which are mainly distributed in the
north temperate zone. About 100 species are from China so far known, with 40 species
extending to Himalayas and Xizang Plateau. The distribution, formation and differ-
entiation of the genus in this region are resembled to Astragalus. These two genera are
usually growing together, composing the main accompanying elements of alpine mea-
dow and steppe.
Caragana is an endemic genus in Eurasian temperate zone and one of constructive
elements of alpine bush-wood. About 100 species are from China, with 16 species in Xi-
zang. According to the elements of composition, 4 species are common to Inner Mon-
golia and Kausu, 4 species to Southwest of China, the others are endemic. This not only
indicates that the species of Caragana in Xizang is closely related to those species of
above mentioned regions, but the differentiation of the genus in the region is obviously
effected by the uplifting of Himalayas, thus leading to the formations of endemic species
reaching up to 50%.
3. An Analysis of Tropical Genera
There are 19 tropical genera in the region. They concentrate in southeast of Xizang
and southern flank of the Himalayas. All of them but Indigofera and Desmodium are
represented by a few species, especially the endemic species. Thus, it can be seen that
they are less differentiated than the temperate genera.
However, the genus Desmodium which extends from tropical southeast and northeast
Asia to Mexio is more active in differentiation than the other genera. According to Oha-
Shi,s system about the genus in 1973, the species of Desmodium distributed in Sino-Hima-
laya region mostly belong to the subgenus Dollinera and subgenus Podocarpium. The
subgenus Dollinera concentrates in both Sino-Himalaya region and Indo-China with 14
species, of which 7 species are endemic in Sino-Himalaya. They are closely related to
species of Indo-China, southern Yunnan and Assam and shows tha tthey have close con-
nections in origin and that the former might be derived from the latter.
Another subgenus extending from subtropical to temperate zone is Podocarpium.
Five out of the total eight species belonging to the subgenus are distributed in Sino-
Himalaya and three of them are endemic.
An investigation on interspecific evolutionary relationship and geographic distribu-
tion of the subgenus shows that the primary center of differentiation of Podocarpium
is in the Sino-Himalaya region.
Finally, our survey shows that owing to the uplifting of the Himalayas which has
brought about complicated geographic and climatic situations, the favorable conditions
have been provided not only for the formation of the species but also for the genus in cer-tain degree. 相似文献
3.
1) The Compositae in Tibet so far known comprise 508 species and 88 genera,
which nearly amounts to one fourth of the total number of genera and one third of the
total number of species of Compositae in all China, if the number of 2290 species and 220
genera have respectively been counted in all China. In Tibet there are all tribes of Com-
positae known in China, and surprisingly, the large tribes in Tibetan Compositae are
also large ones in all China and the small tribes in Tibet are also small ones in all China.
Generally speaking, the large genera in Tibet are also large ones in all China and the
small genera in Tibet are likewise small ones in all China. In this sense it is reasonable to
say that the Compositae flora of Tibet is an epitome of the Compositae flora of all China.
In the Compositae flora of Tibet, there are only 5 large genera each containing 30
species or more. They are Aster, Artemisia, Senecio, Saussurea and Cremanthodium. And
5 genera each containing 10—29 species. They are Erigeron, Anaphalis, Leontopodium,
Ajania, Ligularia and Taraxacum. In addition, there are 77 small genera, namely 87%
of the total of Compositae genera in Tibet, each comprising 1—9 species, such as Aja-niopsis, Cavea and Vernonia, etc.
2) The constituents of Compositae flora in Tibet is very closely related to those of
Sichuan-Yunnan provinces with 59 genera and 250 species in common. Such a situation
is evidently brought about by the geographycal proximity in which the Hengtuang Shan
Range links southeastern and eastern Tibet with northern and northwestern Sichuan-
Ynnnan. With India the Tibetan Compositae have 59 genera and 132 species in common,
also showing close floristic relationships between the two regions. Apparently the floris-
tic exchange of Compositae between Tibet and India is realized by way of the mountain
range of the Himalayas. The mountain range of the Himalayas, including the parallel
ranges, plays a important role as a bridge hereby some members of the Compositae of
western or northern Central Asia and of the northern Africa or of western Asia have
migrated eastwards or southeastwards as far as the southern part of Fibet and northern
part of India, or hereby some Compositae plants of eastern and southeastern Asia or
Asia Media have migrated northwestwards as the northern part of Central Asia.
Some of the species and genera in common to both Tibet and Sinjiang indicate that
this weak floristical relationship between these regions is principally realized through two
migration routes: one migration route is by way of the Himalayas including the parallel
ranges to Pamir Plataeu and Tien Shan, or vice versa. The other migration route is by
way of northern Sinjiang to Mongolia, eastern Inner Mongolia, southwards to Gansu,
Qinghai (or western Sichuan), eastern Tibet up to the Himalayas, or vice versa.
However, Tibet is not entirely situated at a migration crossroad of the floral ele-
ments. An ample amount of the data shows that Compositae flora have a particular
capability of development in Tibet. of the total number of species of Tibetan Com-
positae, 102 species and 1 genus (Ajaniopsis Shih) are endemic. Besides, 8 genera are re-
gional endemics with their range extending to its neighbourhood. The higher percentage
of endemics at specific level than at generic in Tibetan Compositae may be a result of
active speciation in response to the new enviromental conditions created by the uplifting
of the Himalayas. The flora in Tibetan Plateau as a whole appears to be of a younger
age.
3) The uprising of the Himalayas and of the Tibetan Plateau accompanied by the
ultraviolet ray radiation, the microthermal climate and the high wind pressure has, no
doubt, played a profound influence upon the speciation of the native elements of Tibetan
Compositae. The recent speciation is the main trend in the development of the Com-positae flora native in Tibet in the wake of upheaval of the plateau. 相似文献
4.
木兰科分类系统的初步研究 总被引:10,自引:0,他引:10
刘玉壶 《中国科学院研究生院学报》1984,22(2):89-109
A new system of classification of Magnoliaceae proposed. This paper deals mainly with taxonomy and phytogeography of the family Magnoliaceae on the basis of external morphology, wood anatomy and palynology. Different authors have had different ideas about the delimitation of genera of this family, their controversy being carried on through more than one hundred years (Table I). Since I have been engaged
in the work of the Flora Reipublicae Popularis Sinicae, I have accumulated a considerable amount of information and material and have investigated the living plants at their natural localities, which enable me to find out the evolutionary tendencies and primitive morphological characters of various genera of the family. According to the evolutionary tendencies of the characters and the geographical distribution of this family I propose a
new system by dividing it into two subfamilies, Magnolioideae and Liriodendroideae Law (1979), two tribes, Magnolieae and Michelieae Law, four subtribes, Manglietiinae Law, Magnoliinae, Elmerrilliinae Law and Micheliinae, and fifteen genera (Fig. 1 ), a system which is different from those by J. D. Dandy (1964-1974) and the other authors.
The recent distribution and possible survival centre of Magnoliaceae. The members of Magnoliaceae are distributed chiefly in temperate and tropical zones of the Northern Hemisphere, ——Southeast Asia and southeast North America, but a few genera and species also occur in the Malay Archipelago and Brazil of the Southern Hemisphere. Forty species of 4 genera occur in America, among which one genus (Dugendiodendron) is endemic to the continent, while about 200 species of 14 genera occur in Southeast Asia, of which 12 genera are endemic. In China there are about 110 species of 11 genera which mostly occur in Guangxi, Guangdong and Yunnan; 58 species and more than 9 genera occur in the mountainous districts of Yunnan. Moreover, one genus
(Manglietiastrum Law, 1979) and 19 species are endemic to this region. The family in discussion is much limited to or interruptedly distributed in the mountainous regions of Guangxi, Guangdong and Yunnan. The regions are found to have a great abundance of species, and the members of the relatively primitive taxa are also much more there than in the other regions of the world.
The major genera, Manglietia, Magnolia and Michelia, possess 160 out of a total of 240 species in the whole family. Talauma has 40 species, while the other eleven genera each contain only 2 to 7 species, even with one monotypic genus. These three major genera are sufficient for indicating the evolutionary tendency and geographical distribution of Magnoliaceae. It is worthwhile discussing their morphological characters and
distributional patterns as follows:
The members of Manglietia are all evergreen trees, with flowers terminal, anthers dehiscing introrsely, filaments very short and flat, ovules 4 or more per carpel. This is considered as the most primitive genus in subtribe Manglietiinae. Eighteen out of a total of 35 species of the genus are distributed in the western, southwest to southeast Yunnan. Very primitive species, such as Manglietia hookeri, M. insignis and M. mega-
phylla, M. grandis, also occur in this region. They are distributed from Yunnan eastwards to Zhejiang and Fujian through central China, south China, with only one species (Manglietia microtricha) of the genus westwards to Xizang. There are several species distributing southwards from northeast India to the Malay Archipelago (Fig. 7).
The members of Magnolia are evergreen and deciduous trees or shrubs, with flowers terminal, anthers dehiscing introrsely or laterally, ovules 2 per carpel, stipule adnate to the petiole. The genus Magnolia is the most primitive in the subtribe Magnoliinae and is the largest genus of the family Magnoliaceae. Its deciduous species are distributed from Yunnan north-eastwards to Korea and Japan (Kurile N. 46’) through Central
China, North China and westwards to Burma, the eastern Himalayas and northeast
India. The evergreen species are distributed from northeast Yunnan (China) to the
Malay Archipelago. In China there are 23 species, of which 15 seem to be very primi-
tive, e.g. Magnolia henryi, M. delavayi, M. officinalis and M. rostrata, which occur in
Guangxi, Guangdong and Yunnan.
The members of Michelia are evergreen trees or shrubs, with flowers axillary, an-
thers dehiscing laterally or sublaterally, gynoecium stipitate, carpels numerous or few.
Michelia is considered to be the most primitive in the subtribe Micheliinae, and is to
the second largest genus of the family. About 23 out of a total of 50 species of this
genus are very primitive, e.g. Michelia sphaerantha, M. lacei, M. champaca, and M.
flavidiflora, which occur in Guangdong, Guangxi and Yunnan (the distributional center
of the family under discussion) and extend eastwards to Taiwan of China, southern
Japan through central China, southwards to the Malay Archipelago through Indo-China.
westwards to Xizang of China, and south-westwards to India and Sri Lanka (Fig. 7).
The members of Magnoliaceae are concentrated in Guangxi, Guangdong and Yunnan
and radiate from there. The farther away from the centre, the less members we are
able to find, but the more advanced they are in morphology. In this old geographical
centre there are more primitive species, more endemics and more monotypic genera.
Thus it is reasonable to assume that the region of Guangxi, Guangdong and Yunnan,
China, is not only the centre of recent distribution, but also the chief survival centreof Magnoliaceae in the world. 相似文献
5.
白洋淀水生植物区系初步分析 总被引:1,自引:0,他引:1
陈耀东 《中国科学院研究生院学报》1987,25(2):106-113
The Baiyandian Lake lies at 115°56′ E. and 38°55′ N. It is about 8 m above
sea level, with an area about 312 square km. There are abundant aquatic plants here, inc-
luding flowering plants of 30 families, 46 genera, 66 species and 3 varieties besides one in-
troduced species. 32 species are erect ones covering about 48.5% of the total number of species
in this lake, 20 are submerged ones, about 30.3%, 9 are leaf-floating ones, about 13.6% and 5
are floating ones, 7.6%. The soil at the bed of the lake is very fertile and the depth is appro-
priate, favouring various plants. The coverage is large, sometimes it may reach 100%, for
example, in communities of Phragmites communis, Hydrilla verticillata, Hydrocharis dubis,
Trapa bicornis, etc. Although the Baiyandian Lake is located in the temperate zone, the floristic
elements are complex. There are tropic-subtropic elements and elements of high-frigid zone
as well. When compared respectively with the floras of the Lakes Jingbo Lake, Honghu Lake
and Lugu Lake, the flora of this lake is found more similar to that of subtropic Honghu Lake
than to those of the other lakes, which shows that it hase a character transitional between the
south and the north in China. Further studies of the floristic relationships are needed in order
to exploit and use the resources of the aquatic plants in this lake. 相似文献
6.
In the south-east and south Xizang, in cluding Medog, Zayü some western separate
valleys Yadong, Kama near Zentang in Dinggye, Boqu near Zham in Nyalam and
Gyirong, a mild climate prevails because of the very high mountains and the very deep
valleys. According to our preliminary survey, 4/5 of the genera and 7/10 of the
species, i.e. approximately representing all families and genera of the tropical and
subtropical bryofliora of Xizang, are restricted to these localities below the altitude of
2,300 meters. It almost agrees with the previous presumption that the Tsangpo gorge
is the line of connection between two paleoeontinents—Laurasia and Gondwana.
Moreover, the bryoflora of these localities, besides the Indo-Malasian elements and
East Asian elements as the main components, has at least about 40 genera in common
with south America, Australia and Africa. According to the historical phytogeogra-
phical point of view, the distribution range of centain genera is formed through a
period of long historical development. The same is true for the area of different
species, although they are found in widely separate areas right now, yet they might
have once a continuous distribution in certain historical age. The Indian plate collided
against the eastern part of Laurasia and afterwards the Australasian plate moved to
the north. All these might have dispersed the Gondwana elements as far as to the
southeastern part of Xizang.
It is very interesting to note that of the 32 genera of bryophytes endemic to East
Asia, 13 have recently been found in the southeast and south Xizang and also in the
neighbouring regions, i.e. Yunnan, Sichuan, where there are many genera being in
common with southeast and south Xizang and also highly concentrated in distribution.
This may suggest that the Himalayas, being the highest and youngest mountain range,
have changed the atmospheric circulation, and have created a new ecological condition
between tropical and frigid zones, which have given the distribution of the newly form-
ed genera a suitable circumstance to survive. It may be presumed that the region
covering counties Medog, Zayü, Yadong etc. in southeastern and southern parts of the
Himalayas is a new center of distribution of bryophytes under the influence of the up-heaval of the Himalayas. 相似文献
7.
This paper is a preliminary study on the Sabiaceae in aspects of its morphology,
taxonomy and geography. We propose that the Sabioideae and Meliosmoideae as two
new subfamilies of Sabiaceae according to the external morphology, flower structure
and geographical distribution of these two genera respectively.
This paper follows the taxonomic concepts of Luetha Chen on Sabia and C. F.
van Beusekom on Meliosma. We agree with them for their classification of these two
genera above the specific rank. As to the revision work of Sabia by van de Water
and C. F. van Beusekom’s work on Meliosma we disagree for their unduly broad
specific concepts. We rather treat the species of these two genera according to their
habitats in regions on a relatively narrower sense. The genus Sabia of China are
classified into 2 tribes, with 16 species, 5 subspecies and 2 varieties in which 4 sub-
species and l variety are as new combinations, the genus of Meliosma in China are
classified into 2 subgenera with 29 species, and 7 varieties of which 4 varieties are new
combinations.
After examining the affinity of the species of Sabia and Meliosma in China and
its neighboring nations such as Burma, Japan and Bhutan, we found that their migra-
tion initiated from China, as the primitive species of these two genera occured in
northeast and central part of Yunnan, sou theast of Sichuan, north of Guizhou and
west of Hubei, the region may probably be the main origin of these two genera.
As shown in tables 1 & 2, the localities where the species of these two genera den-
sely populate they are from Yunnan, Guangxi, and Guangdong coinciding with the
concepts of C. F. van Beusekom and van de Water about the distribution of exotic
species of these two genera, it may reasonable be pointed out that the center of distri-
bution of these two genera is Yunnan, Guangxi, Guangdong and nieghboring nations,
upper Burma and northern Vietnam. Futhermore, it may be seen that starting from
this center the number of species become less and less as they proceed far and far awaybut become more advance in evolution. 相似文献
8.
中国特有的露蕊乌头亚属及铁破锣的染色体研究 总被引:3,自引:0,他引:3
商效民 《中国科学院研究生院学报》1985,23(4):270-274
The paper reports chromosomal number and chromosomal morphologies of
annual Aconitum gymnandrum endemic to China and Beesia calthifolia for the first
time. Of the two spcies, chromosome number is same (X=8, 2n=16) and chromosome
average lengths are 6.17μ , 10.73μ respectively. The longest chromosome 1, the short
chromosomes 3-5, 7 and the shortest chromosome 8 are metacentrical (m), the chro-
mosomes 2, 6 are submetacentrical (sm), and the pairs 4, 5, 8 have satellites in the
karyotype of A. gymnandrum. In B. calthifolia, all of the chromosome 1-5 are the
long m, the chromosomes 6, 8 are the short sm and the 7 is telocentrical (t). The pairs
3, 4, 6 have satellites.
According to the comparison of karyotypes of three subgenera—subgen. Para-
conitum, subgen. Aconitum and subgen. Gymnaconitum in Aconitum, the evolution trend
of chromosomes is further discussed.
Finally, the relationship between Aconitum and Beesia is also discussed in thispaper. 相似文献
9.
论胡桃科植物的地理分布 总被引:1,自引:0,他引:1
路安民 《中国科学院研究生院学报》1982,20(3):257-274
The present paper aims to discuss the geog raphical distribution of the Juglandaceae
on the basis of unity of the phylogeny and the process of dispersal in the plants.
The paper is divided into the following three parts:
1. The systematic positions and the distribution patterns of nine living genera in
the family Juglandaceae (namely, Engelhardia, Oreomunnea, Alfaroa, Pterocarya, Cyclo-
carya, Juglans, Carya, Annamocarya and Platycarya) are briefly discussed. The evolu-
tional relationships between the different genera of the Juglandaceae are elucidated. The
fossil distribution and the geological date of the plant groups are reviewed. Through
the analysis for the geographical distribution of the Juglandaceous genera, the distribu-
tion patterns may be divided as follows:
A. The tropical distribution pattern
a. The genera of tropical Asia distribution: Engelhardia, Annamocarya.
b. The genera of tropical Central America distribution: Oreomunnea, Alfaroa.
B. The temperate distribution pattern
c. The genus of disjunct distribution between Western Asia and Eastern Asia:
Pterocarya.
d. The genus of disjunct distribution between Eurasia and America: Juglans.
e. The genus of disjunct distribution between Eastern Asia and North America:
Carya.
f. The genera whose distribution is confined to Eastern Asia: Cyclocarya, Platy-
carya.
2. The distribution of species
According to Takhtajan’s view point of phytochoria, the number of species in every
region are counted. It has shown clearily that the Eastern Asian Region and the Coti-
nental South-east Asian Region are most abundant in number of genera and species. Of
the 71 living species, 53 are regional endemic elements, namely 74.6% of the total species.
The author is of the opinion that most endemic species in Eurasia are of old endemic
nature and in America of new endimic nature. There are now 7 genera and 28 species
in China, whose south-western and central parts are most abundant in species, with Pro-
vince Yunnan being richest in genera and species.
3. Discussions of the distribution patterns of the Juglandaceae
A. The centre of floristic region
B. The centre of floristic regions is determined by the following two principles: a.
A large number of species concentrate in a district, namely the centre of the majority;
b. Species of a district can reflect the main stages of the systematic evolution of the
Juglandaceae, namely the centre of diversity. It has shown clearly that the southern
part of Eastern Asian region and the northern part of Continental South-east Asian
Region (i.c. Southern China and Northern Indo-China) are the main distribution centre
of the Juglandaceae, while the southern part of Sonora Region and Caribbean Region
(i.c. South-western U.S.A., Mexico and Central America) are the secondary distribution
centre.
As far as fossil records goes, it has shown that in Tertiary period the Juglanda-
ceae were widely distributed in northern Eurasia and North America, growing not only
in Europe and the Caucasus but also as far as in Greenland and Alaska. It may be
considered that the Juglandaceae might be originated from Laurasia. According to
the analysis of distribution pattern for living primitive genus, for example, Engelhar-
dia, South-western China and Northern Indo-China may be the birthplace of the most
primitive Juglandaceous plants. It also can be seen that the primitive genera and the
primitive sections of every genus in the Juglandaceae have mostly distributed in the
tropics or subtropics. At the same time, according to the analysis of morphological cha-
racters, such as naked buds in the primitive taxa of this family, it is considered that
this character has relationship with the living conditions of their ancestors. All the
evidence seems to show that the Juglandaceae are of forest origin in the tropical moun-
tains having seasonal drying period.
B. The time of the origin
The geological times of fossil records are analyzed. It is concluded that the origin
of the Juglandaceae dates back at least as early as the Cretaceous period.
C. The routes of despersal
After the emergence of the Juglandaceous plant on earth, it had first developed and
dispersed in Southern China and Indo-China. Under conditions of the stable tempera-
ture and humidity in North Hemisphere during the period of its origin and development,
the Juglandaceous plants had rapidly developed and distributed in Eurasia and dis-
persed to North America by two routes: Europe-Greenland-North America route and
Asia-Bering Land-bridge-North America route. From Central America it later reached
South America.
D. The formaation of the modern distribution pattern and reasons for this forma-
tion.
According to the fossil records, the formation of two disjunct areas was not due to
the origin of synchronous development, nor to the parallel evolution in the two con-
tinents of Eurasia and America, nor can it be interpreted as due to result of transmis-
sive function. The modern distribution pattern has developed as a result of the tectonic
movement and of the climatic change after the Tertiary period. Because of the con-
tinental drift, the Eurasian Continent was separated from the North American Conti-
nent, it had formed a disjunction between Eurasia and North America. Especially, under
the glaciation during the Late Tertiary and Quaternary Periods, the continents in Eu-
rasia and North America were covered by ice sheet with the exception of “plant refuges”, most plants in the area were destroyed, but the southern part of Eastern Asia
remained practically intact and most of the plants including the Juglandaceae were
preserved from destruction by ice and thence became a main centre of survival in the
North Hemisphere, likewise, there is another centre of survival in the same latitude in
North America and Central America.
E. Finally, the probable evolutionary relationships of the genera of the Juglanda-ceae is presented by the dendrogram in the text. 相似文献
10.
张芝玉 《中国科学院研究生院学报》1982,20(4):402-409
1. The present paper describes the observations of chromosome numbers and
karyomorphology of 2 species of 2 endemic genera and I endemic species of Chinese
Ranunculaceae: Asteropyrum peltatum (Franch.) Drumm et Hutch. 2n=16, x=8;
Kingdonia unifolia Balf. f. et W. W. Sm. 2n=18, x=9 and Calathodes oxycarpa Spra-
gue 2n=16, x=8. The chromosome counts of three ranunculaceous genera are repor-
ted for the first time.
2. The morphylogical, palynological and cytological date in relation to the syste-
matic postition of Asteropyrum, Kingdonia and Calathodes within the family Ranun-
culaceae are diseussed and resulted in following conclusions:
(1). On the basis of the basic number x=8 in Asteropyrum, it is further con-
firmed that this genus is distinct from the r elated genera such as Isopyrum, Dichocarp-
um and other allied taxa.
The comparison of Asteropyrum with Coptis shows that they are identical in short
chromosomes, with magnoflorina and benzylisaquinodine type of alkaloides, but dif-
ferent from coptis in the chromosome numbers (T-type), pantocolpate pollens, united
carpels and the dorsi-ventral type of petioles. In view of these fundamental morpho-
logical and cytological differences, Asterop yrum is better raised to the level of Tribe.
However Asteropyrum and Coptis may represent two divaricate evolutional lines of
Thalictroideae.
(2). The systematic position of the genus Kingdonia has been much disputed in
the past. We support the view of Sinnote (1914), namely, the trilacunar in leaf
traces “the ancient type”, appeared in the angiosperm line very early, while the uni-
lacunar of Kingdonia may be derived from the trilacunar. On the basis of the chromo-
some numbers and morphylogical observation, the present writer accept Tamura’s and
Wang’s treatment by keeping Kingdonia in Ranunculaceae instead of raising it to a
family rank as has been been done by Forster (1961). Kingdonia and Coptis are
similar in having short chromosome with x=9, but with one-seeded fruits; therefore it
is suggested that placed into Thalictroideae as an independent tribe, indicating its close
relationship with Coptideae.
(3). Comparing with its allies, Calathodes being with out petals, seems to be more
primitive than Trollius. But Calathodes differs from Trollius with R-type chromosomes in having T-type chromosome with x=8 and subterminal centromere. Those charac-
teristics show that it is very similar to the related genera of Thalictroideae. But as
Kurita already pointed out that most speci es of Ranunculus have usually large long
chromosomes but some species have compar ativelly short chromosomes, therefore we
regard T-type and R-type chromosomes appear independently in different subfamilies
of Ranunculaceae. According to Tamura, G alathodes seems to be closely related to
Megaleranthis, because of the resemblance in follicles. But due to lack of cytological
data of the latter genus, the relationship between the two genera still is not clear pen-
ding further studies. From the fact that the morphology and chromosomes of the
Calathodes differs from that of all other genera of the Helleboroideae, we consider
Calathodes may form an independent tribe of its own with a closer relationship withTrollieae. 相似文献
11.
应俊生 《中国科学院研究生院学报》1994,32(5):389-410
秦岭是中国长江和黄河两大水系的分水岭,位于北纬32°5′至34°45′;东经104°30′至115°52′,最高峰达3767m。该山区是我国温带植物区系最丰实的地区之一,约有种子植物3124种,隶属于158科,892属。包括热带属220属,温带属563属,和中国特有属39属。根据该山区植物区系中各大科、主要植物群落优势种和组成种类的温带性质以及温带属在整个植物区系中的主导地位。该山区的植物区系和植被具有明显的温带性特点。特有种和非特有种的分析结果表明,该山区植物区系的特点还表现在高度特有性和以中国-日本森林植物区系为主体方面。 根据古植物学资料分析,秦岭地区植物区系的起源时间不会晚于晚白垩纪;植物群落的主要成份可能以原地生长的种类为主;秦岭及其邻近古老山区,不仅对自身的植物区系和植被具有较大的发生意义,而且对东亚植物区系具有始生性质。 相似文献
12.
太白山位居秦岭的中段,为秦岭山脉第一高峰。该山区是我国温带植物区系最丰富的地区之一,
约有种子植物1782种,隶属于125科,657属,包括热带属130属,温带属436属和特有属24属。该地
区20个较大科的种数,约占其全部植物区系的66.6%,其中特有种653种。本文对这些大科的性质及
其在植物区系和植被中的作用进行了分析讨论。在分析了全部属和植物群落优势种的地理分布的基础
上,着重讨论了该地区与其他九个山区的植物区系关系。
本文对植被垂直带划分;主要植物群落的基本特点和区系相似性;物种多样性与海拔高度变化的关
系以及生活型谱与不同坡向和海拔变化的关系等作了具体分析。对该地区主要植物群落的形成时期以
及对秦岭地区植物区系的过渡性质提出了自己的看法。从植物学角度出发,秦岭地区作为亚热带和温带
植物的分界线的提法与该地区的植物区系和植物群落性质以及水热条件情况不相符合 相似文献
13.
郝日明 《中国科学院研究生院学报》1997,35(6):500-510
中国种子植物特有属是局限分布于中国行政区域范围内的植物成分,就其分布特点看,集中分布于中国南部亚热带广阔区域。由于中国地域广袤,虽然大多数特有属分布在东亚自然地域范围内,但南部特有属的分布范围已进入古热带植物区的马来亚森林植物亚区的北部,而西部的特有属的分布范围已进入青藏高原地区。局限于不同地域分布的特有属,各自的起源发生、所经历的地质历史过程存在一定差别。本文以自然地理区划作为研究中国种子植物特有属分布区类型的依据,将中国特有属分布区类型划分为中国东部和中部特有分布变型、中国南部特有分布变型、中国西部特有分布变型和中国北部特有分布变型4类。其中中国南部特有分布变型所含特有属为热带区系成分,其它3个特有分布变型所含特有属为温带区系成分。这样能较客观地反映中国特有属的自然地理特征,有利于研究局部地区植物区系的地质历史演变过程。 相似文献
14.
The Xizang (Tibetan) flora with numerous endemics is of importance in Chi-
nese flora. According to recent statistics there are in Xizang 27 genera of spermatophytes
endemic to China, being only 2.25% percent of the total number of genera in the Xizang flora.
Four of them are regarded as palaeoendemics (14.81%) and the others as neoendemics (85.19%).
These endemic genera, of 30 species and 3 varieties, belong to 17 families, of which, Umbelli-
ferae contains 6 genera, 7 species and 3 varieties; Compositae has 6 genera and 7 species, and
Gentianaceae 1 genus and 2 species. All the other families each comprises one genus with a
single species.
The cosmopolitan families together comprising 14 genera with 15 species have the highest
perecentage (52.92%) and the tropical ones (5 families, 5 genera with 5 species) come to the next
(29.42%), followed by the temperate ones (3 families, 10 genera with 10 species) (17.66%). It
shows that these endemic genera are obviously related to the tropical flora and temperate one
in essence.
According to the number of species, the genera endemic to China and occurring in Xi-
zang flora may be grouped as fallows.
Monotypic endemic ones 14 (51.85%)
Ditypic endemic ones 6 (22.22%)
Oligotypic endemic ones 4 (14.81%)
Small endemic ones 3 (11.11%)
The formation of the endemic genera is correlated with the topography, climate and en-
vironmental conditions, and they may have resulted from the diversification in geography and
climatic influence for a long time. The southeastern part of Xizang Plateau is of very diverse
ecological conditions, with the adequate precipitation, which may explain the concentration of
these endemic genera in this region.
The largest similarity coefficient (38.30%) of the genera endemic to China and occurring
in Xizang is with those in Qinghai Plateau, next, with those in Yunnan and in Sichuan pro-
vinces (both 27.60%), which shows that these endemic genera are related to the floras of the
regions mentioned above.
The difference in the horizontal distribution of these endemic genera is obviously between
the southern and northern parts of Xizang Plateau. The vertical distribution of the genera is
also rather obvious, from 800 m to 5200 m above sea level, but concentrated in the zone of 3000
m to 4500 mm. Therefore their occurrence in Xizang is not only affected by the historical
environmental conditions but also controlled by the horizontal and vertical distribution.
The origin and evolution of some endemic genera, such as Psammosilene, Parateropyrum,
Sphaerotylos, Salweenia, Ajaniopsis, Xizangia, Sinoleontopodium, are discussed in this paper.
Parateropyrum, a monotypic palaeotropic endemic, belongs to the tribe Atraphaxideae in-
cluding Atraphaxis, Calligonum and Pteropyrum. It may be a comparatively advanced group
in the tribe, and is closely related to the genus Pteropyrum which is distributed in western
Asia. The genus Parapteropyrum has possibly survived as a palaetropic-tertiary relic in this
region.
Sphaerotylos, a member of the subtribe Sphaerotylinae, the tribe Boehmerieae in the family
Urticaceae, is a comparatively primitive genus in the tribe Boehmerieae so far known. As the
other subtribes, such as Boehmerinae, Sarconchlamydinae, Orecnidinae and Maoutinae, are dis-
tributed in the tropics, rarely in the subtropics, the genus is no doubt a palaetropic -tertiary
relic.
Sinoleontopodium, belonging to the tribe lnuleae in Compositae, is also related to the ge-
nus Leontopodium. It is probable that the genus Sinoleontopodium arised later than the other.
We come to the conclusion that the southern part of Xizang Plateau is also one of thecentres of the origin and differentiation of genera endemic to China. 相似文献
15.
本文结合地史初步探讨了第三纪以来武夷山苔藓植物可能发生的变化。武夷山的苔藓
植物主要为东亚区系成分和旧热带区系成分,与泛北极区系成分的相似性也相当明显。东亚
特有属(5个)系组成武夷山苔藓植物区系的重要因素之一,它低于黄山和西天目山的9个和
7个,与黄山等组成一个共同的苔藓植物东亚特有属的分布中心。从各方面的分析推测,这 类植物可能起源于第三纪,系一类“孑遗植物”。 相似文献
16.
湘西北壶瓶山自然保护区植物区系 总被引:1,自引:0,他引:1
壶瓶山自然保护区具有丰富的植物区系成分,现知维管束植物有205科(蕨类和拟蕨类 植物40科,裸子植物7科,被子植物158科),839属,约1961种(包括154变种)。其中,古 和原始的科、属不乏其代表。从种子植物属的分布区类型的比较分析,该区具有我国15个种子植物属的分布区类型中的14个,表明了与世界各地区植物区系的联系程度。另一方面,该 地区的植物区系虽含有丰富的热带成分,但根据各类温带属占该区总属数的百分比以及分布于该地区的中国特有属中的木本属几乎所有都是落叶的乔木或灌木,该区的植物区系性质明显偏重于温带性质。而且,这种温带性质可能与该区的山体海拔高度有着重要的联系。 相似文献
17.
台湾位于欧亚大陆东南缘的海洋中,地处热带的北部和亚热带的南部,约为21°45′~15°56′N,119°18′~124°34′E,是中国最大的岛屿。它是受季风气候强烈影响的地区之一,热量丰富,雨量充沛,干湿季明显。具有一个非常丰富的岛屿和山区植物区系。就其种子植物而言,约有186科,1201属,3656 种,包括热带属742属,温带属346属。根据台湾植物区系中各大科、主要植物群落优势种和中国特有种的地理分布以及热带属在整个植物区系中的主导地位,台湾地区的植物区系主体具有明显的亚热带性质。中国台湾本地特有种十分丰富,其比例远高于中国特有种的比例。这似乎表明台湾植物区系是一个古老区系在多次地质事件侵袭后又起活化的历史演变的结果。新老成分并存、共同发展是台湾植物区系的重要特点。通过台湾全部属和非特有种在周边地区地理分布的分析,中国台湾植物区系与中国大陆的关系最为密切,是东亚植物区系的重要组成部分,因此在植物分区上应属于泛北极植物区的东亚植物区系。 相似文献
18.
本文对我国种子植物特有属作了初步研究,提出如下几点粗浅的看法:
1.根据我国各特有属的现代地理分布格局,大部分特有属具有明显的温带性特点。
2.我国特有属在水平分布上具有极不均匀的特点。各特有属的广布程度都很低,生态特
化现象十分明显。在垂直分布上,则主要分布于中海拔地区。特有属数目并不随海拔增高而
增多。
3.根据特有属分布的密集程度和分布区边界的密集交叠情况,划定了三个特有属分布中 心,即川东—鄂西中心, 滇东南—桂西中心和川西—滇西北中心。前二中心可能是残遗中心,后一中心则可能为分化中心。 相似文献