China can truly be called the kingdom of bamboo. Approximately half of the world's known species of bamboo can be found here, from diminutive ones standing 10 cm high, to giants reaching the heights of 40 m, a part of whose culms between two joints can be turned into water buckets. The geographical distribution of bamboo in China is very wide; bamboo grows from the sea level to as high as 3800 m in the alpine areas. For several thousand years, bamboo has been an essential element of Chinese culture and played a very important role in the daily lives of Chinese people. Nowadays, our understanding of the biology of this plant, whose name is so firmly associated with Chinese civilization, is far deeper than our ancestors would have imagined, but the modern Chinese, just like their predecessors, still live in the world of bamboo.
The Fast-growing “Big Grass”
In China, the history of using bamboo for building goes back to seven thousand years, and it was during Qin and Han dynasties (221BC to AD220) that bamboo became an important building material. Even now it remains to be the principal material which the ethnic groups, such as Dai, Wa and Jingpo, living in the southwest of China, use for the construction of their dwellings. A book from Qing Dynasty (1644-1911) says: "Use bamboo instead of tiles to make your roof, use bamboo instead of bricks to put up your walls, use bamboo instead of wood to make your doors." Different varieties of bamboo were used for different purposes, for example spotted bamboo (Phyllostachys bambusoides) was used to make ship towlines, due to its elasticity and durability. Moso bamboo (Phyllostachys edulis), straight and solid, was used for construction, whereas black bamboo (Phyllostachys nigra) was the best material available for making musical instruments such as flutes.
Unless you have seen with your own eyes, it is hard to believe that a 20 cm bamboo shoot can grow overnight into a plant 2 m high. Bamboo is one of the world's fastest growing plants and watching it grow is one of the most amazing and magical sights the natural world can offer. It is said that, standing in the middle of a bamboo grove during a silent night, you can actually hear the sound of bamboo growing and of its segments forming.
Bamboo's extremely fast growth is its most special quality, which increasingly attracts the attention and interests of people today. It takes a tree 50 years to reach a height of 10 m, but bamboo reaches the same height after only 50 days, and after five years it can be used for commercial purposes.
The secret of this special quality lies in its unique internal structure, which deserves a closer look.
Even though bamboo greatly resembles a tree, it, strictly speaking, belongs to the family of grasses.
An important difference between bamboo and true trees is in their growth mechanisms. Generally, the growth of a tree only occurs at its tip, where specialized cells, capable of continuous division, are located. The division of these cells slowly drives the tree upwards until it reaches its maximum height. In bamboo, however, these growth cells are not restricted to the tip of the culm, but are also present at each segment. To make an analogy, if a tree were a building where the construction only takes place on the top, bamboo would be a building where construction goes on each floor already built, and the construction on all floors carries on simultaneously, completing the construction work in a short time.
Question remains, however, why other members of Poaceae family, such as wheat and corn, whose growth mechanisms are similar to those of bamboo, cannot grow to 2 m overnight like bamboo? In 2012 the scientists at the Chinese Academy of Forestry have discovered the secret of the extraordinary speed of bamboo growth. They have found that the reproductive cells in the segments of bamboo are not just dividing very fast, but also grow extraordinarily quickly. This, however, means that bamboo must require a huge amount of energy while growing, so where does this energy come from? In fact, bamboo prepares well and early for this challenge – it does not only accumulate large quantities of plant hormones, but also builds up large reserves of sugars and enzyme catalysts which aid in the breakdown of these sugars. These “fuel tanks”, similar in function to camel humps, is what makes such extraordinary fast growth possible.