> Pflanzen - Pflegen und Ernten:

> Behandlung von Bambus:

Abb.: Zuschneiden von Bambus-Setzlingen, Philippinen
[Bildquelle: Jeff_Werner. -- http://www.flickr.com/photos/jeffwerner/531466724/in/set-72157600151000055/. -- Zugriff am 2009-09-15. -- Creative Commons Lizenz (Namensnennung, keine kommerzielle Nutzung, share alike)]

Abb.: Bambuskultur, Nanjing (南京), China (中国), um 1900
[Bildquelle: James Ricalton. -- http://www.flickr.com/photos/24443965@N08/3484008662/. -- Zugriff am 2009-10-08. -- Creative Commons Lizenz (Namensnennung, keine kommerzielle Nutzung, share alike)]

David Fairchild gab 1903 folgende Darstellung über die Bewirtschaftung von Bambuswäldern in Japan:

"JAPANESE MANAGEMENT OF BAMBOO GROVES. One of the best posted bamboo growers in Japan informed the writer that twenty years ago he did not know that his groves, which were then in a neglected state, had any money value, but that to-day those parts of his farm on which the groves are situated are its most valuable portions. The attention which he bestows upon them now is very inexpensive, but almost as careful as that given to any other of his crops. The following forest methods are largely those which Mr. Tsuboi described as, from his experience, the best. These are applicable with slight variations to the three principal timber bamboos in Japan, and pertain in a general way to the culture of the ornamental species. Plate III: Bamboo forests. Fig. 1. A well-kept forest of Phyllostachys quilioi growing on poor soil filled with gravel. Weeding has not been as recently done as in that part of the forest shown in PI. II. The two photographs from which these plates were prepared were taken from points not 20 yards apart in the forest of Mr. Isuke Tsuboi, of Kusafuka. Photographed by Yendo. Fig. 2. A badly kept forest of timber bamboo (Phyllostachys quilioi ) growing on good soil adjacent to the well-kept forest shown in PI. II. This shows the effect of not weeding, thinning out, or fertilizing. Photographed by Yendo. Plate II: "A well-kept forest of Phyllostachys quilioi growing on good soil, showing an open drainage ditch in foreground and the thick mulch of leaves and straw which cover the ground. Age probably over 50 years. Photographed by Yendo.", Japan The land chosen for a bamboo grove should be dug over to a depth of 1½ feet the autumn previous to being planted, and, if a heavy soil, should have worked into it a good quantity of trash from the stable. The plants should be set out at an equal distance from each other at the rate of about 300 to an acre, or 12 feet apart each way. If the soil is a dry one, the ball of earth and roots should be planted below the surface of the soil, but if a wet one a mound should be made and the plants set in the upper portion of it. After planting it is important, as already remarked, that the soil between the plants should be given a heavy mulch of straw, under which is a layer of cow manure. This mulch should be 7uaintained during the entire year. In the beginning the roots should be supplied with an abundance of water and in the autumn should be given plenty of rotted manure. If some of the plants die, they should be replaced by others so as to maintain as complete a stand as possible. It is essential as the new shoots spring up that the ground at their bases should be shaded by the foliage. The semiobscurity of a Japanese grove is not only its greatest charm, but one of the necessary factors of its growth. The sooner the ground can be shaded by the plants the better. For the first three years at least all the shoots that appear should be allowed to mature, but after the grove is once well established only the largest shoots should be permitted to grow, the others being cut out as soon as they appear above the ground. This thinning process throws the strength of the plants into a comparatively few large culms, and gradually increases the height and strength of the forest. In regions where the snows are so heavy that they break down the plants the practice of bringing the tops of several culms together and fastening them with rope is sometimes followed. The wigwam-like masses formed in this way are able to support without injury the weight of snow. No culm should be cut for timber purposes until it is at least four years old, as before this time the wood is not mature. On the other [S. 22] hand, if left standing too long the wood becomes too brittle and loses in value, and the forest besides is benefited by the cutting out of the four-year-old stems. The crop of new shoots is larger. This thinning-out process should be so done that as few gaps as possible are made in the forest and the semiobscuritv below the mass of foliage is maintained. The crop of new shoots varies in size every alternate year. A poor crop would mean 6 to 7 per cent of new shoots and a good crop 12 to 14 per cent. As there are commonly 10,000 culms in a hectare (or 4,545 in an acre) of properly planted grove ten to fifteen years old, this would mean the production of 600 to 700 culms per hectare for a light crop and 1,200 to 1,400 for a heavy one. These figures werevery kindly furnished the writer by Dr. T. Shiga, chief of the imperial forest management in Tokyo. The experience of Mr. Tsuboi has been that some kinds of forest trees if standing in a grove prevent the growth of the bamboos near them. Oaks and chestnuts, he declares, are especially objectionable in this respect, while persimmons do not seem to affect in the least the production of new bamboo shoots. The effect of weeds in a forest is undesirable, and although comparatively few species are able to live in such a deep shade these should be dug out as from any cultivated field. Attention to these various details makes a great difference in the amount and quality of timber produced. A grove is not to be looked upon as merely a thicket and left to take care of itself, but as a plant culture which requires attention. Plates II and III show the effects of different methods of treating parts of the same grove. One important element in the culture of this peculiar timber plant is the fact that a whole forest may bloom and die in a single season, and that it is not possible—as yet—to tell beforehand when this blooming will take place. The intervals between these periods are, however, so long that they are not taken into consideration by the Japanese farmer when he buys a bamboo grove. Little accurate information is obtainable regarding the length of life of the various Japanese species. but Phyllostachys humilis has the reputation in Japan of blooming oftener than either Phyllostachys quilioi, Phyllostachys mitis, or Phyllostachys nigra, the other three important timber species. A small grove near Kawasaki which bloomed this season (1902) was reported by the owner to have once bloomed about sixty years before. As there always remain in the field a number of living rhizomes, after the death of the forest, these renew the latter in a few years, so that the actual loss to the owner does not include the cost of replanting. This is the case at least with the Japanese bamboos. As culms which have bloomed are poor in quality, the practice is followed of cutting them as soon as possible after they show signs of blooming. [S. 23] In Japan, where bamboos and rice arc often grown in adjoining plats of ground, some trouble is experienced from the underground stems spreading into the neighboring fields. To prevent this a ditch 2 feet wide and as many feet deep is dug about the grove and kept open by several rediggings during the year. This method is said to be a satisfactory one. It is a difficult matter, however, after a field has once been planted to bamboos, to clear it satisfactorily for other crops, for there is a mass of these tough rhizomes that are very difficult to dig out. The harvesting of bamboo poles is not done before August, as culms cut earlier than this date are likely to be attacked by insects, not having had time to sufficiently harden. A Kyoto grower of black bamboos remarked that the Kobe exporters, by insisting on having their bamboos for export cut earlier than this date, had seriously injured the foreign demand, as the quality of the wood was much injured by this early harvest. A saw is often used in cutting the shoots, by making cuts on opposite sides of it near the base. When cut, the poles are classified, tied into bundles, and stacked like hop or bean poles to dry. In the lumber yards of Japan these stacked poles of bamboo form a prominent feature." [Quelle: Fairchild, David <1869-1954>: Japanese bamboos and their introduction into America.  -- Washington : Govt. print. off., 1903.  -- 36 S. : VIII Tafeln.  -- 23 cm. -- S. 21 - 23. -- Online: http://www.archive.org/details/japanesebamboost00fair . -- Zugriff am 2009-09-20

Abb.: Bambusernte, Changzhou ( 常州市), China (中国)
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Da das Ernten von Bambus arbeitsintensiv ist und die Arbeitskräfte dabei sehr verstreut sind, besteht die Gefahr, dass sie Kahlschlag betreiben, wie Jules J. A. Janssen bemerkt:

"A problem with the harvest is that it is very labour intensive and requires an extensive workforce. These people are widely scattered over the forest and cannot be controlled. For casual labour, the only interest is their day's income; the next harvest is beyond [S. 5] their scope. This tends to result in over-cutting within short distances of the road and less or no cutting at longer distances. A reduction of productivity is the result. This will not happen if the cutters are also the owners, i.e. a co-operatively owned bamboo plantation." [Quelle: Janssen, Julius Joseph Antonius <1935 - >: Building with bamboo : a handbook / Jules J.A. Janssen. -- 2nd ed. -- Warwickshire : Intermediate Technology Publications, ©1995. -- 65 S. : Ill. ; 25 cm. -- ISBN 1-85339-203-0. -- S. 5f.]

Dabei sollte die Ernte von Bambusstängeln in Plenterbetrieb bzw. als Auflichtung geschehen, wie Dunkelberg fordert:

"Der Kahlhieb mag die gebräuchlichste Hiebmethode sein, aber auf eine sinnvolle 'Bambuswirtschaft' bezogen ist sie unökonomisch. Meist betreiben die Eingeborenen im Landesinneren keine Wiederaufforstung; deshalb sollte der Plenterhieb bevorzugt werden. Bei den weiten Halmabständen monopodialer Spezies ist die Entnahme der Bambusstangen eine typische Plenterung. Bei der Beerntung von horstbildenden Bambusarten trifft eher die Bezeichnung Läuterung oder Auflichtung zu (Hosseus). In 2-4 jähriger Wiederkehr entnimmt der Hieb dem Horst bis zu 30% der reifen Stangen. Die richtige Jahreszeit in den Subtropen wäre Herbst und Winter, in den Tropen die Trockenzeit. Der Abhieb sollte nicht höher als 30 cm über dem Boden liegen (Hildebrand). Das Fällen geschieht am besten mit dem Haumesser (Machete o.ä.). Wenn abgesägt, dann verfault der zugehörige Wurzelteil nicht, zum Nachteil der neuen Triebe. Das Verfaulen wird beschleunigt, wenn anschließend die Wurzel kreuzweise durchschlagen wird, damit Regen und Sickerwasser besser eindringen können (Hackel). Der Hieb sollte die Verbindung der verbleibenden Halme untereinander nicht beeinträchtigen. Fehlt im Horst die gegenseitige Stützhilfe, dann neigen sich die Halme, und man erhält künftig nur noch verbogene Stangen. Für die Wahl des Hiebturnus sind die Kenntnisse von der jährlichen Leistungsfähigkeit der Horste unumgänglich. Nach Pearson entfällt auf ca. vier alte Halme ein neuer Halm. Es wäre mehr als vier Jahre nötig, die alten Halme zu ersetzen. Die Leistungsfähigkeit, neue Halme im Horst hervorzubringen, ist artenverschieden (Tab. 28). Art Ort/Zeit % Bambusa arundinacea Orissa, 1959 10% Bambusa tulda New Forest, 1958 18% Teinostachym dullooa Assam, 1955/6 34% Dendrocalamus hamiltonii Assam, 1955/6 38% Tab. 28: Durchschnittsproduktion an jungen Halmen im Jahr; Angaben in % der alten Halme; nach Mathauda. Zur Festlegung des Hiebsatzes sollte die mittlere Jahresproduktion der jeweils letzten 15 Jahre berücksichtigt werden; dadurch lässt sich am besten eine nachhaltige Ernte sichern. Mit der ersten Halmernte kann erst dann begonnen werden, wenn der Horst seine volle Hiebreife erlangt hat; das wird nicht vor 6 Jahren nach seiner Begründung sein. Innerhalb der staatlichen Wälder in Indien werden die Horste alle 3-4 Jahre beerntet, und zwar nur die älteren Halme (Prasad). Etwa 10 Stangen sollten stehen bleiben, wobei die Peripherie des Horstes vom Hieb verschont bleiben sollte. Die belassenen Stangen stützen nicht nur die jungen Triebe, sondern erhalten auch die volle Wuchskraft der Rhizome (Hildebrand). Zwei- bis fünfjährige Bambusstangen gelten als geeignetste Bau- und Werkstoffe. Bei dreijährigem Umlauf ist mit einer Ernte zwischen 3.000 bis 15.000 Halmen/ha zu rechnen, das entspricht einer Trockensubstanz von 7,5 bis 38 t/ha (Hubermann). In Deutschland ist der jährliche Holzeinschlag ebenfalls an die Nachhaltigkeit der Wälder gebunden. Er beträgt nur 3,5 fm/ha, was etwa 1,4 t/ha lufttrockenem Holz entspricht (Bertelsmann) Nach dem Fällen müssen die Zweige so sorgfältig von den Stangen entfernt werden, daß die Außenhaut des Rohres nicht verletzt wird (Austin). Beim Abschlagen des Astansatzes werden oft breite Rindenstreifen über die nächsten Internodien hin aus der Rohrwand herausgerissen. Der Schutzschild gegen Nässe und Schädlinge ist dann undicht." [Quelle: Dunkelberg, 1978. -- S. 92]