Native Vegetation Emerges as Sustainable Solution Against Invasive Himalayan Shrub
A groundbreaking study conducted by the Uttarakhand forest department has demonstrated that native vegetation serves as an exceptionally effective and environmentally sustainable method to control the proliferation of Eupatorium adenophorum. This invasive perennial shrub, locally known as kala bansa or banamara (meaning 'killer of forests'), poses a severe threat to Himalayan ecosystems. The research provides crucial insights for restoring degraded lands across the region.
Research Methodology and Experimental Design
The comprehensive study, initiated in 2021 across the Kumaon region and concluded in August of the previous year, revealed that strategic planting of native grasses, ringal (hill bamboo), indigenous shrubs, and local tree species significantly suppressed the aggressive spread of this invasive weed. Manoj Kumar, a junior research fellow with the forest department's research wing, emphasized the findings, stating, "Restoration using native grasses represents a sustainable and ecologically viable approach for managing the shrub's invasion in degraded areas."
Botanists have long warned that kala bansa has become a serious menace to both forest biodiversity and agricultural productivity due to its unchecked growth across extensive Himalayan territories. The research specifically aimed to identify long-term solutions through native vegetation-based rehabilitation of degraded forest land.
Experimental Site and Treatment Implementation
The experiment was meticulously carried out in Dwarson Compartment-16, a mid-Himalayan pine–deodar mixed forest spanning 1.5 hectares. This site was heavily infested with the invasive shrub, resulting in poor native regeneration and significantly altered vegetation structure. Prior to implementing the experiment, researchers manually removed all standing Eupatorium adenophorum shrubs to establish uniform baseline conditions across the study area.
Researchers divided the site into four distinct plots, each subjected to different rehabilitation treatments. This approach allowed for thorough evaluation of various vegetation structures – including vertical, horizontal, and canopy-forming growth forms – in suppressing the regeneration of the invasive shrub.
Detailed Assessment and Quantitative Findings
Vegetation assessment was conducted using systematic 1m×1m quadrat sampling, with 40 randomly placed quadrats in each treatment plot. The abundance of Eupatorium adenophorum was carefully recorded to measure population density under different rehabilitation approaches.
Sanjiv Chaturvedi, chief conservator of forests (research wing), presented compelling data: "The untreated control plot (0.30 hectares) showed the highest infestation levels, with 5,983 individuals and a mean density of 149.57 individuals per square meter. This indicates rapid invasion in open, disturbed habitats that lack competitive vegetation." He further noted that all rehabilitation treatments significantly reduced invasive density compared to the control plot.
The research revealed particularly striking results:
- The tree plantation plot (0.25 hectares) recorded only 479 individuals, representing over 90% reduction compared to the control plot, likely due to increased shading and root competition
- The grass plantation plot demonstrated the lowest abundance, with just 243 individuals and a mean density of 6.07 individuals per square meter
- The ringal and shrub plantation plot (0.50 hectares) recorded 328 individuals with a density of 8.20 individuals per square meter
Most Effective Treatment Identified
Researchers observed that dense grass cover, dominated by Thysanolaena maxima (commonly known as tiger grass), minimized exposed soil and effectively inhibited seed germination, making it the most effective treatment overall. Chaturvedi elaborated, "Overall, grass plantation demonstrated the highest suppression efficiency, followed by ringal and shrub combination, and finally tree plantation treatment."
This research provides forest managers and conservationists with scientifically validated, practical approaches for combating one of the Himalayas' most problematic invasive species while promoting sustainable ecosystem restoration through native vegetation rehabilitation.
