The Role of Rhizomes in Growth and Spreading Habits of Bamboos
Bamboos, often referred to as "the wonder plant," are renowned for their rapid growth and unusual resilience. One of the key factors contributing to bamboos’ ability to thrive and regenerate is their unique underground structure known as rhizomes. A common misconception arises when individuals and literature refer to rhizomes as the root system. Clear morphological distinctions between roots and rhizomes exist within the soil, contributing collectively to the anchoring system. However, it's important to note that the primary responsibility for anchoring lies with the rhizomes, despite their shared role in this function with the roots.
Rhizomes play a vital role in the growth and spreading habits of bamboo, making them a fascinating subject for botanists and environmentalists. In this blog, bamboo bioproducts delve into the world of bamboo rhizomes to understand their significance and how they contribute to the extraordinary characteristics of this versatile plant.
What are Rhizomes?
Rhizomes are specialised horizontal (and in some cases, vertical) stems that grow underground, serving as a vital organ for certain plants, including bamboos. These elongated structures serve several functions, such as nutrient storage, vegetative propagation, and, most importantly, the expansion patterns and survival of the bamboo plant. For bamboos in particular, there are 2 primary types of rhizome growth patterns; monopodial (running or invaders) and sympodial (clumping or non-invaders).
Growth and Spread through Rhizomes
Unlike most plants that primarily rely on seeds for reproduction, bamboo's rhizomes enable bamboos to spread rapidly. As a result, many bamboos have been incorrectly categorised as invasive. This, however, is a myth that stems from a lack of understanding about the different types of bamboos and their respective growth patterns. Clumping bamboos, for example, have rhizomes that expand vertically while staying close to the original plant, leading to dense and compact growth. In other words, one hectare of clumping bamboo, such as Bambusa vulgaris, when planted, will always remain within the one hectare it was originally planted in. Conversely, running bamboo species send out long and adventurous rhizomes that can extend several feet away from the parent plant, facilitating its propagation over larger distances. This sometimes requires running bamboos to be managed properly in order to ensure stable spreading patterns.
Related Article: Running vs. Clumping Bamboos
Bamboos’ spreading strategy through rhizomes is highly adaptive and efficient. The underground rhizomes act as a storage system for carbohydrates and nutrients, ensuring that the plant has reserves to survive adverse conditions and regrow after disturbances like fires, cutting or deforestation. As conditions become stable, these stored resources are utilised to produce new shoots, facilitating the plants’ regeneration. Because bamboos are actually considered to be a grass, this means that bamboos can be farmed sustainably; they do not need to be replanted after a harvest. Among other qualities, this is one of the reasons why bamboo bioproducts will use Bambusa vulgaris, a non-invasive clumping bamboo, as the source of biomass for a bamboo bioproducts mill in Jamaica.
Colonisation, Erosion Control, and Bioremediation
The ability of bamboos to colonise and stabilise soil is yet another remarkable contribution of their rhizomes. These underground stems help prevent soil erosion by binding soil particles and reducing surface runoff, making bamboos essential plants for maintaining the infrastructure of slopes and riverbanks. Due to their erosion control capabilities, bamboos play a crucial role in protecting vulnerable landscapes from environmental degradation and the potentially destructive effects of heavy rainfall and floods.
Moreover, bamboos’ positive impact on the environment extends beyond erosion control. As bioremediators, bamboos possess the ability to absorb and filter various pollutants from the soil and water, making them invaluable tools for environmental restoration. Studies have shown that bamboos can efficiently absorb heavy metals, such as lead, cadmium, and chromium, from contaminated soil, effectively detoxifying the affected areas. Additionally, rhizomes play a crucial role in this process by facilitating the transportation of pollutants to the bamboo shoots, where they are sequestered and stored. In conclusion, clumping bamboos display exceptional resilience against environmental factors such as hurricanes and fires. Their robust resistance can be attributed to the extensive rhizome structure that extends deep underground. As a result, even in situations where culms are subjected to burning, harvesting, or breakage, these bamboos can rejuvenate without requiring replanting. The primary source of their stability and growth resides beneath the ground, within their rhizomes. These rhizomes, which contain buds, activate growth in response to diverse stimuli, leading to the emergence of new rhizomes and subsequently giving rise to new culms.
By harnessing bamboos’ bioremediation capabilities, we can revitalise contaminated, overused and idle lands, mitigate the impact of industrial pollutants, and promote sustainable land-use practices. The combination of bamboos colonisation, erosion control, and bioremediation abilities highlights their importance as a multifunctional plant with significant ecological and environmental benefits.
While a bamboo's spreading habits through rhizomes are often advantageous, they can also pose challenges for land managers if the growth patterns of different species are not understood. As aforementioned, many bamboos have been wrongly labelled as invasive species due to a lack of understanding of plant anatomy and growth patterns. In many cases, it is actually a myth that bamboos are invasive.
Rather, human-facilitated spread generally plays a large part in the uncontrolled growth that in some cases can lead to running bamboos becoming invasive by encroaching on neighbouring properties. The results of this study published by INBAR support the claim that Bambusa vulgaris has been wrongly categorised due to a lack of understanding and acknowledgement of human involvement in the spread of Bambusa vulgaris.
Guide to Farming Bamboo Sustainably Understanding the role of rhizomes in the bamboo life cycle empowers us to harness this incredible plant's ecological significance and make informed decisions to preserve its unique characteristics for generations to come.
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