MSc

Kerala is recognized as a significant biodiversity hub for bamboo species. The
state is home to 28 different bamboo species, covering an extensive area of 0.24 million
hectares. Despite this rich biodiversity, the total availability of bamboos from both forests
and homesteads amounts to only 0.304 million tonnes, falling short of the required 0.62
million tonnes. Though there are some information regarding the growth performance of
economically important bamboo species, which are among the designated priority species
by INBAR, their effects on improving the site productivity by altering the
physicochemical and biological properties of the soil are very much lacking. Moreover,
there are some perceived thoughts that litter of bamboos are making impediments rather
than improving the soil. In this backdrop, the investigation entitled “Litter dynamics and
soil changes under six-year-old bamboo stands” was undertaken in an existing
bambusetum at College of Forestry during the period 2022-23. The study aimed to
observe the growth behaviour, litter production pattern and nutrient turnover under six
different bamboo species viz., Bambusa vulgaris Schrad, Bambusa balcooa Roxb.,
Bambusa tulda Roxb., Dendrocalamus brandisii (Munro) Kurz., Dendrocalamus asper
(Schult.f.) Back.ex Heyne and, Dendrocalamus longispathus Kurz. Changes in soil
physico-chemical and biological properties were also assessed over a period of one year.
In terms of growth performance, Dendrocalamus brandisii stood out with the
highest clump height (14.95m) and internodal length (44.01cm); For culm girth and
clump circumference, Bambusa vulgaris shown highest value (22.21cm, 6.47m) closely
followed by Dendrocalamus brandisii, while Bambusa tulda showed relatively poor
performance in these parameters. However, in number of culms per clump
Dendrocalamus asper recorded highest closely followed by Bambusa tulda.
Litter production varied substantially among different bamboo species, with
Bambusa vulgaris having the highest annual litter production (9.64 Mg ha-1
year-1
), while
Bambusa balcooa exhibited the lowest (6.98 Mg ha-1
year-1
). Litterfall followed a
bimodal distribution pattern, with the major peak occurring after N-E monsoon, during
the winter and a minor peak during S-W monsoon. The major composition of litter
primarily consisted of leaf, accounting for over 70% of total litterfall, followed by twigs
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and sheath. During litter decomposition, a three-phase decomposition pattern was
observed for all species. Mass loss of litter samples followed a negative exponential
relationship. Notably, species with higher initial nitrogen concentrations, such as
Bambusa tulda, showed rapid decomposition rates. The decay rate coefficient varied
among species, with Bambusa tulda having the highest decay rate coefficient (0.292
month-1
), and Bambusa balcooa the lowest (0.123 month-1
).
Amongst soil physico-chemical and biological properties, Bambusa balcooa
exhibited higher soil organic carbon content, porosity, and lower bulk density at the
topsoil compared to open field conditions. The availability of nutrients like nitrogen,
phosphorus, and potassium varied significantly among species, with higher contents
being observed under Dendrocalamus longispathus. For biological properties also, the
Dendrocalamus longispathus displayed the highest microbial population with greater
accounts from the fungal population while open showed the lowest. Bacterial population
varied substantially between species and sampling periods. Dehydrogenase activity was
observed highest in the Bambusa tulda while lowest under bamboo less control.
The present research findings, provide valuable and quantitative insights into
six important bamboo species in terms of their growth performance, litter dynamics, and
role in improving physicochemical, and biological properties of soil. The generated data
from the current study will help to enumerate the ecological and environmental
implications of bamboo cultivation and would serve as a basis for various managerial
interventions in bamboo-based land use practices