Chapter III. The Distribution of Bamboo
There are 490 kinds of bamboo in the world, according to an authority who has listed and described them all. So far 60 species have been identified as definitely Chinese. Probably there are still others to be added lo the list. The 60 Chinese species are distributed among eight genera, the three largest being Arundinaria, Phyllostachys, and Bambusa comprising 12, 21, and 16 species respectively.
Generally speaking, bamboo does not grow wild north of 35°, i.e., a line drawn from Pingliang, Kansu, east along the Yellow River to Kaifeng, Honan, and thence along the Kiangsu-Shantung border to the sea. It is more frequent toward the south, and especially on the low-lying plains and valleys near the southeast coast. The hill and mountain varieties of bamboo are to be found farther inland on the slopes and foot-hills bordering the tributaries of the Yangtse, the West, the Kiulung, and the Min rivers. The varieties occurring on the higher places are usually dense thickets of scrub, some even growing at an altitude of 13,000 feet. Phyllostachys pubescens (Mao Chu 毛竹), our largest bamboo in the lower Yangtse valley, grows best at 2,000 feet altitude. In the larger towns and cities of Shantung and Chihli, bamboo is cultivated in gardens for ornamental purposes only. The bamboo material made into various articles, such as brooms, furniture, etc. is shipped entirely from the south. Some varieties are hardy in even more northerly places but are never found wild. They could never succeed on the poorer soil and through the longer freezing seasons of the north.
China Proper is said to occupy about 1,500,000 square miles. This excludes Manchuria, Mongolia, Sinkiang, Tibet, and Kokonor. If we include the Manchurian provinces of Fengtien, Heilungkiang and Kirin, the area totals over 1,890,000 square miles. Those who have been in China a long time and have studied the forest problem at all, know how the timber is fast disappearing. Books have been written, special investigations have been made, talks and lectures have been given on the subject of China's disappearing forests, but to no avail. One of the factors in this disregard may be the prevalence of bamboo. Bamboo can always be had; according to one estimate, about 120,000 square miles are taken up with bamboo forests and isolated groves. We believe this to be a conservative estimate. Excluding Manchuria, the timber belt follows the great S-like curve made by the mountain ranges beginning east of Poyang Lake with the Nan Shan. It follows south and west along the Fukien-Kiangsi border, turning west along the Kwangtung-Kiangsi border to Liping, north to Ichang, across the Yangtse, northwest and west along the Tsingling range, then south along the Tibetan frontier across the Szechwan Marches and western Yun-nan following the Mekong river. The bamboo belt cannot be said to follow any such definite line for the reason that bamboo is ubiquitous. It occurs on cultivated farms as well as in wildernesses and no cliffs on high mountains. True, it is found mixed with coniferous forests in various places. Wilson reports it mixed with the Silver Fir (Abies Delavayi) on these lopes of Wa-wu Shan, Szechwan. Aug. Henry mentions it as abundant north of Ichang in the coniferous forests. We have seen it ourselves in Chekiang mixed with Cunninghamia, Cryptomeria, and Pinus. Therefore, in a sense, bamboo, especially the mountain varieties, can be said to follow the ranges. But as we have seen, it is not confined to this kind of environment.
To get a fairly accurate idea of the' distribution of bamboo three methods have been used, (1) An analysis of literature. (2) The preparation and sending out of questionnaires. (3) Direct questioning and personal observation by investigators. The most fruitful and certainly the surest sources of information culled by the first method are the botanical books which describe the species collected, and mention as well the places from which they come. Such works as E. G. Camus's "Les Bambusees", the "Index Florae Sinensis'', and the "Plantae Wilsonianae" are the most reliable. Other books of a more popular and less technical character which are nevertheless just as reliable are Wilson's "A Naturalist in Western China" and Shaw's "Chinese Forest Trees and Timber Supply". Of a more special nature we may mention Rhodin's "Notes on the Flora and the Reafforestation Possibilities of the Province of Cheki'ing", Aug. Henry's ''Notes on the Economic Batany of China", and "The New Atlas and Commercial Gazetteer of China". The last has commercial and forestry maps on which to a certain extent one may rely. Then, questionnaires have been sent out to places where previous maps and literature indicated nothing. Up to the present all the questionnaires have not yet come back. They were designed with a view to simplicity and quick returns consistent with the information wanted, and so far they have sufficed. The aid of Consuls, customs officials, and missionaries in various parts of China has been invoked. Regarding the last method of obtaining information, personal observation has contributed its quota in the form of reports from agents specially delegated through the kind offices of the Chinese Government Bureau of Economic Information to work on the problem. To this we have added our own experience. We hope that the new distribution map which contains the results of these investigations here summarized will be an improvement on those previously published.
It is best to outline briefly the distribution of bamboo by provinces as follows : --
1. CHIHLI. In gardens around Peking and Tientsin, and possibly elsewhere. Cultivated only.
2. Shansi. Shansi-Honan border north of Hwaikingfu, Honan. The northern part is treeless,
3. Shensi, Cultivated around Sianfu and all along the Wei valley. Also in the Hangchun and Hingan districts. Found in the valley of the Han and along its tributaries from Fo-ping-ting to Ningsia. It is abundant on the Tsingling mountains up to 7,000 feet altitude where it forms dense thickets.
4. Kansu. On the lower slopes of the southern mountain ranges. Information from these regions insufficient.
5. Shantung. In Laichow, Weihsien, Tsinan, Yenchow, Tsaochow and Ichow it is cultivated in gardens. Rocky soil and dry seasons unfavorable to bamboo.
6. HONAN. It is said that bamboo used to grow wild in the north when the climate was less dry. It is reported around Hwaiking. but there is none at Kaifeng or between Kaifeng and Kweiteh. Honan is said to be the most treeless province in China. Kaoliang stalks replace bamboo for fences and various other uses. A recent report direct from Nanyangfu says there is some bamboo in the nearby mountain valleys; also around Kwangchow in the southeast.
7. KIANGSU. Occurs chiefly in the central and southern parts of the province, but is restricted locally to isolated groves owing to the fact that most of the land is given over to the cultivation of rice, cotton, wheat, barley, beans, rape, and vegetables. Cultivated around Sungkiang, Shanghai, Kunshan, Soochow, Wusih, along the Grand Canal to Yangchow, and up the Yangtse (o Nanking. A great deal of scrub found on the hills around Soochow and Wusih,
8. Anhwei. Central to the southwestern portion adjoining Kiangsi. Bamboo is cultivated around Anking and Wuhu districts.
9. HUPEH. Found on the slopes of Shengmu Shan in the northwest and down the Han valley; also on the southern slopes through
Chushan, the valley of the Nan Ho and beyond to Nanchang. Another belt extends east along the Yangtse valley from Patung to Nantu, north as far as Singshan (to 3,000 feet and thickets to 8,000 feet), south to Changyang, about Ichang and all through the Fang district up to 9,600 feet altitude. Direct reports from Wuchang say it extends over the adjacent foot-hills.
10. SZECHWAN AND SZECHWAN MARCHES. Found generally throughout the Red Basin, the extreme eastern point being Wushan. Found in abundance especially in the southeastern part around Luchow, down the Yangtse to Chungking, and souihward to Nanchuan and the Chin-shan hills. It is reported from Chenglu and west to the Tibetan frontier near Tachienlu up to 13,500 feet altitude. Also south from Chengtu to Kiatingfu and the environs of Mt. Omei, which with Washan and Wawushan (described by Wilson) are said to be covered with dense growths of bamboo mixed with conifers. Reported around Paoning and Suiting.
11. Chekiang. Generally plentiful. Abundant in the following districts: Huchow, Mokanshan, Hangchow and up the Tsien Tang river, Shaohing, Chenghsien, Ningpo, and Haimen; also in the south from Lungcbuan to Wenchow.
12. KIANGSI. Found around Kiukiang; from Nankang to Yining; from Nanchang southwest to Yuanchow via Tungshan; in the extreme east around Kwangsinfu and Hokow; Anjen (east of Nanchang) south along the Kiangsi-Fukien border and the valley of the Fu Ho to Ningtu; and finally in the southwest around Kan- chow and west to Nananfu through the upper valleys of the Kan Kiang and tributaries,
13. Hunan. Reported from the Changsha district. The regions from Yiyang to Packing bordering on the Tzu river are the most productive.
14. KWEICHOW. In the valleys of the south, northeast of Singyifu. Further data lacking.
15. FUKEN. Very plentiful. Most abundant along the Min and Kiulung rivers; in the north from Shaowu to Yenping, and thence to Foochow with branches to the north via the Siyangki and south via the Shwang ki. In the south the regions southeast of Ting- chow centering around Yungting on the Kwangtung border to Pingho, across to Amoy and up the Kiulung river constitute a very productive territory.
16. Kwangtung. Occurs everywhere. Chief centers are Wankwai- shan in the south ; Hongkong, Canton, Macao, and the valleys of West River, the Bamboo river coming down from Pakmashan on the Kwangsi border, and the Pei Kiang or North river coming down from the north. Swatow at the mouth of the Han is another center.
17. Kwangsi. Reported from Wuchow, also from along the Cassia river to Kweilin. Some bamboo obtained from the south from the regions around Nanning.
18. Yunnan. The only place it has been definitely reported from is Mengtsz and from the mountains in the southeast oi; cliffs up to 8,000 feet. No further information.
A Map of China showing the Distribution of Bamboo.
The regions in which bamboos grow are shaded. The black circles in the north locate cities where bamboo grows in gardens. The bamboo areas on this map are those about which there are definite reports, no supposition or guess work being employed.
[Image: Bamboo Map]
The references on which the following list of species is based are as follows:
(i) Camus: Les Bambusees. Faul Lechevalier. Paris, I9i3.
(2) Forbes & Hemsley: Index Florae Sinensis. The Linnaean Society.
(3) Freeman-Mitford, A.B.: The Bamboo Garden. London, 1896.
(4) Henry, Aug.: Notes on the Economic Botany of China. Shanghai, 1893.
(5)' Wilson: Plantae Wilsonianae.
(6) Rhodin, C.T.: Notes on the Flora and the Reafforestation Possibilities of the Province
of Chekiang. Shanghai, 1924.
A List of the Different Kinds of Bamboo Found in China
Total, 60 species.
Like Other plants bamboo may thrive in different environments. Bamboo is found at sea-level and from there up as high as 13,000 feet. We see it thriving on irrigated plains, but we find it also on cliffs high up on mountain sides. We wonder at its luxuriant growth in the loamy soil of the rich valleys and forests, and again at its hardness in thriving on gravelly hill-tops and upper slopes where most of the good soil has been washed away. In the tropics we have a wonderful collection of bamboos. but we also find them in northern latitudes. Some of their hardy relatives are cultivated in the temperate and even colder regions of China. Collectors have imported and grown them successfully in England, which is considerably farther north than Peking.
There are, however, certain outstanding conditions which may be called the most favorable, and in which the plant grows best. Bamboos are hungry plants and respond to generous treatment. This point has been discussed before in connection with the cultivation of bamboos. In a wild state the conditions may be judged by the character of the bamboos which grow there. If such observations are summarized, it will be found that moisture is perhaps the foremost necessity of the ideal environment. A very good way to observe this fact is to measure every day a growing bamboo shoot, keeping accurate account of the weather conditions at the same time. It will be found that the curve of growth day by day follows closely that of the percentage of moisture in the air. This fact has been corroborated by several independent investigators. Our own observations showed that on rainy days and on cloudy days with a great deal of humidity in the air, the growth was most rapid, while on days which were dry with a hot sun or on which a coldish wind was blowing, growth was very slow, i.e. the gain for that day was very little. In mid-summer when the streams dry up we have observed a high mortality among the bamboos inhabiting the upper valleys of mountains. The explanation is that the soil, which is very scarce in these places, (merely what is washed down from above and caught between the rocks and loose stones) is sufficient to maintain plant life only if properly irrigated. When the stream, therefore, dries up under the rays of a hot continuous sun and the stones below become heated, thus accelerating the evaporation of what soil moisture is left, the roots wither and the bamboo dies despite the chance presence even of a trickling remnant in the stream-bed. Occasionally this happens, but normally frequent mountain showers swell temporarily these streams, the plants get a brief soaking along with a bit of fresh soil, and they take a new lease on life. In dry year, however, as it was on the mountains of Chekiang in August, 1924, when there was no relief and the south valley bottoms down to the lower slopes gradually dried up under the pitiless glare of the sun, the bamboos turned yellow, the leaves whitened and dropped off, and many of the canes fell over like stiff dead sticks. In other places, it weathered the drought because the soil was deeper, and therefore better able to retain its moisture, or because of a location which was less exposed. There is still further evidence that moisture is an important factor in the environment of bamboos. They are found most abundantly along the waterways, among the rice paddies, in coastal regions where they can be bathed by sea mists, in the tropical forests and jungles, but never in dry places such as the loess country of northern Shansi, or in rocky soil, as on the hills of Shan- tung, All this indicates that moisture is the most decisive factor in deter- mining the distribution of bamboo.
An analysis of the conditions in which bamboo grows best in a natural state will show at once that shelter is also of some importance. Protection on the north and east seems to be of great assistance in bringing about better growth. The reason is obvious. The cold winds are usually from the north and northeast, and where temperature is also an object, protection from cutting winds is an advantage, and in some places a necessity. The young shoots when they come up are extremely tender, and if in the spring when they first appear they are whipped about as they grow taller and battered by the older canes around them, growth will be very much hampered. A southerly exposure is the best. Observation convinces us of this. Some practical illustrations we have seen on the Chekiang hills, especially about Mokanshan, In two separate cases the best growth of Phyllostachys pubescens (Mao chu, 毛竹) was observed on southwesterly slopes. The breezes from the south are warmer, less violent, and more moist.
The very fact that most of the bamboos occur in the tropics is sufficient to show that, generally speaking, warmth is desirable. Indeed, their demand for moisture is of necessity contingent upon the presence of higher temperatures, since in colder regions the moisture in the soil would freeze and destroy the roots. Conversely, we have shown that extremes of heat are fatal if not mitigated by sufficient moisture. With these factors must be considered soil, a third important constituent of the favorable environment. It is usually the case that in the presence of warmth and moisture, the work of mineralizing decaying leaves and the production of soil in general goes forward at a rapid rate. A loamy or alluvial soil is ideal for bamboos. Some varieties are hardy with respect to climatic conditions, but a closer analysis will reveal the fact that their hardiness arises chiefly out of the rich soil, which has been provided for them to grow in. In nature, such provision does not always occur, in which case the canes will soon die, and eventually the underground stem. A slightly sandy soil is not fatal nor is a clay soil, but the small canes and pale leaves indicate that conditions are not right. From observations in nature, from the experience of farmers, and from the practice of gardeners, we may conclude that the presence of rich alluvial soil such as we have in the Yangtse valley and the frequent occurrence of bamboo of certain kinds are significant of the close relation existing
between the two.
Besides moisture, shelter, a southern exposure, warmth, and a rich loamy soil, bamboo is governed somewhat in its distribution by the surrounding flora. Fairchild says that bamboo will not grow in the presence of oak (Lih, 栎; Ch'ing-kang, 青岗) or chestnut (Lih, 栗) trees. Persimmon trees (shi, 柿子), on the other hand, do not check the production of shoots. This seeming fastidiousness is probably due in part to the effect of root excretions, which in the one case are harmful but in the other neutral. Some may have observed the frequent association of bamboos with conifers. In many places, in Chekiang, in the Fang district of Hupeh, and elsewhere, there are heavy growths of bamboo interspersed with coniferous forests. Certainly from the standpoint of beauty, the dark green of the latter makes the proper background for the arching plumes of bamboo. It is interesting to think of these two survivals of a past age co-operating, as it were, to resist the onslaught of more recent, rapidly maturing species.
Another factor that may have something to do with the association of bamboos with coniferous trees is the character of their respective root-systems and the latter's influence on space relations in the soil. A spreading root-system near the surface of the ground such as that of Pterocarya stenoptera ( Yuan pao foong, 元宝枫) would naturally interfere more with the growth of bamboo and the production of new shoots than would the deeper roots of such trees as Cunninghamia (Shan sung, 杉松) and Cryptomeria (Liu shan, 柳杉) for instance. So far as the tree is concerned, this association is beneficial if the seedling can succeed through the first year. Since bamboo canes grow so rapidly, the danger is that the seedling may become uprooted by an elongating shoot. Because of the conical shape of the shoot, however, an actual collision with the seedling will be avoided. The shoots will push up through the soil past the seedling, crowding it a little, but that will be all, unless the rootlets should happen to get tangled around the point of the shoot as it comes through. But the chance of this happening is very slight. It is not certain even that a seed would germinate in close proximity to a clump-forming bamboo, for example. On the other hand, the shelter and protection from the withering rays of the sun in summer afforded by the leafy plumes of bamboo is a distinct advantage to the seedling, especially at this young stage in its life history. As the years pass, the seedling grows into a sturdy sapling. There is less danger of crowding canes now because the spreading limbs have begun to cast deeper shadows and the roots have begun to crowd and envelop the underground stem of the bamboo. Strangulation of the new buds combined with the reduction of food-making minerals in the vicinity of the sapling is not an impossible explanation of the check to shoot and cane production. The sapling has the advantage of continued growth in size, which the bamboo has not. This favors the success of the tree. When it has grown taller, once more the region around its base will be free, for its roots have penetrated below the level of the bamboo root-system, and the lower limbs will have dropped off through self-pruning. There is one aspect, however, which is not so favorable to the young tree, especially to those intolerant of shade. In his study of the reafforestation possibilities of the province of Chekiang, C. T. Rhodin says that the slopes are singularly unproductive. Though there is plenty of pine and fir, yet at 35 years of age the forest should have carried three times the present amount of wood. This forest is not cut for fire-wood, so that cannot be the reason. He explains that the mixture of bamboo with pine and fir seems to handicap the pines, which do not thrive in the shade. "The brooms of the bamboos shoot practically everywhere up above the crown roof and by their constant thrashing of the pine crowns hinder the pines in their struggle for light."
As far as the bamboo is considered, the growth of the forest trees in and about the area which it occupies is a protection. In the first place, these trees help to stabilize air-currents. In other words, they form windbrakes, thus saving the half-grown tips of the shoots from destruction. Moreover, they have a moderating effect on the temperature of the surrounding regions. Their leaves in the course of their metabolic activities absorb a great deal of the sun's heat. At the same time transpiration goes on. This added moisture thrown out into the air cuts down the evaporation of water from the soil, a very desirable thing for bamboo. Lastly, the roots of trees help to hold the moisture in the soil. During the rain a small portion of the precipitation adheres to the leaves, about a sixth, depending on the amount of leaf surface; about a third constitutes surface run-off; while the remainder sinks into the soil. Of this the humus, like a moist blanket over the soil, holds a part, the roots absorb another part, to be made over into cellulose or transpired, and the remainder drains off underground. However, there is a danger in overcrowding, which would prevent the light from getting to the bamboo. But overcrowding is rare in China, owing to the fact that forest trees of any sort are very rarely left to attain respectable dimensions before they are chopped down for coffin wood or fuel. Moreover, the rapid growth of bamboo must be borne in mind. Nevertheless, there is an economic problem in the competition between these valuable market plants. We need timber trees but we need better bamboo also. There is a call for the adjustment of the relations between these two, a task plainly for the skilled forest technician with a knowledge both of timber trees and bamboo.