Does over-abundance of &lt;i&gt;Bambusa&lt;/i&gt; &lt;i&gt;bambos&lt;/i&gt; (L.) Voss. alter edaphic properties?

M G U A Millangoda,H M S P Madawala

doi:10.4038/cjs.v47i3.7535

Abstract

A preliminary study was conducted to determine any modifications to basic soil properties following over-abundance of Bambusa bambos, a native bamboo species, that rapidly expanding its population in Intermediate and Dry Zone forests in Sri Lanka. Soil samples taken from representative sites of bamboo-dominated (BAM) and non-bamboo (NBM) forest patches were analyzed for pH, total nitrogen (N), phosphorus (P), soil moisture and microbial biomass carbon (MBC). A growth assay was carried out with Ricinus communis seedlings in BAM and NBM soils (sterilized/unsterilized) in a glasshouse. The soil analysis revealed significantly higher N, P and moisture in BAM soils than in NBM. BAM soils were clayey in nature compared to silty soils in NBM. Ricinus communis grown in BAM soils performed better throughout the experimental period, perhaps due to higher soil nutrients. Ricinus communis grow better in unsterilized soils irrespective of bamboo, indicating a facilitative role of soil microbes on the growth of plants. The preliminary results suggest that either B. bambos spread has the potential to increase the soil fertility status or else B. bambos expands its population preferably on nutrient-rich clayey soils. Therefore, further studies are needed in order to confirm the impacts of B. bambos on edaphic properties which may eventually influence the growth of co-occurring native species.

Highlights

The invasion of exotic species can cause drastic impacts in their introduced habitats, especially in island nations (Vitousek et al, 1997; Britton-Simmons and Abbot, 2008)
A growth assay has been carried out using field soils (BAM and NBM) with Ricinus communis seedlings to confirm whether these edaphic changes can affect the growth of R. communis, a common shrub in the forest undergrowth
The results suggest that B. bambos expands its population preferably in clay-rich soils rather than its invasion makes soils clay-rich

Summary

INTRODUCTION

The invasion of exotic species can cause drastic impacts in their introduced habitats, especially in island nations (Vitousek et al, 1997; Britton-Simmons and Abbot, 2008). Recent studies have reported sudden expansion of populations of some native species, including bamboos, causing negative impacts similar to invasive species. Scientists have taken a long time to recognize the fact that even some native species show the ability to expand populations in their resident communities, sometimes even encroaching adjacent natural forests. Expanding populations of bamboo species in their native habitats is a common occurrence in many tropical countries (Bai et al, 2013; Peng et al, 2013; Tang et al, 2013; Prematilleke et al, 2014). Invasion of exotics has been recognized as an emerging problem in status reports of many countries, the negative impacts of expanding populations of native species are usually overlooked. In Sri Lanka, expansion of native bamboo species (Ochlandra stridula and Bambusa bambos) in their resident forest communities has been reported. A growth assay has been carried out using field soils (BAM and NBM) with Ricinus communis seedlings to confirm whether these edaphic changes can affect the growth of R. communis, a common shrub in the forest undergrowth

MATERIALS AND METHODS

RESULTS AND DISCUSSION

CONCLUSIONS