TITLE:
Do Plants Have a Choice of Traits to Be Modulated? Evidence from an Invasive Plant Mikania micrantha Kunth in Different Urban Environments
AUTHORS:
Achyut Kumar Banerjee, Swayambhu Ghosh, Anjana Dewanji
KEYWORDS:
Phenotypic Plasticity, Traits, Urbanization, Invasive Plant, Germination
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.4,
March
30,
2017
ABSTRACT: The
successful establishment of an invasive plant in a novel environment has been
attributed to the phenotypic plasticity of plant traits, with most studies focussing
on vegetative trait plasticity in either experimental and/or natural habitat
conditions. This study explores the role of phenotypic plasticity, in both
vegetative and reproductive traits, of an invasive plant Mikania micrantha growing as a ground cover in diverse urban areas in the city of Kolkata, India.
Quadrat based plant and soil sampling was conducted in three habitat types,
namely roadsides, natural areas and abandoned plots, from four regions within
the city. The above ground biomass and fitness related vegetative and seed
traits were estimated from the plant samples whereas soil macro-and
micro-nutrients as well as soil health (in terms of organic carbon and
microbial biomass carbon) were estimated from the soil samples.
Habitat-specific selection of traits in M. micrantha was
observed in this study. In
roadside population which has more chances of long
distance dispersal, the
excessive production of reproductive biomass as a compensatory response to the
low germination ability of the seeds was evident. In natural areas which are
more prone to anthropogenic disturbance and where the plant has greater chances
of local spread, modulation of both vegetative (higher SLA) and reproductive
traits (lighter seeds with faster germination ability) helped the plant to
maintain its population. In abandoned plots where there was more number of
associated species, the longer span of germination and increased population height
ensured the survivability of M. micrantha in the community. Thus, a continuous
monitoring program to check for M. micrantha growth
should be prioritized in urban areas due to its immense trait plasticity in
different habitat conditions where uncontrolled growth can lead to its
establishment and spread, thereby making its control more difficult.