Participatory Ecological Assessment of Farmer Perspectives on Management of Invasive Ageratina adenophora in Eastern Bhutan

TL;DR

This study explores how Bhutanese farmers perceive and manage the invasive weed Ageratina adenophora, combining local knowledge with scientific methods to improve sustainable control.

Contribution

The study introduces a participatory approach to quantify farmer insights on invasive weed management, integrating local knowledge with scientific strategies.

Findings

Farmers prioritize managing Ageratina adenophora's weedy characteristics and control methods.

Farmers prefer uprooting, burning, and burying over herbicides for weed control.

The species' prolific seed production and rapid growth are identified as key invasion drivers.

Abstract

Ageratina adenophora
, a native plant to Mexico, has rapidly invaded Bhutan's landscapes from subtropical foothills to subalpine zones. This has resulted in suppressed native plant biodiversity, impacts on economically important plants, altered soil properties, and crop yield losses. Although impacted farmers managing this weed possess deep, experiential knowledge, their insights remain under‐quantified and under‐utilized. We aimed to assess farmers' perspectives on the impacts and management of
A. adenophora
in eastern Bhutan. A focus group discussion with village leaders was held in Kanglung to refine nine literature‐derived themes into five farmer‐relevant priority areas: (1) weedy characteristics, (2) growth habit, (3) competitive effects, (4) control methods, and (5) awareness. A structured questionnaire was administered to 91 randomly selected farmers to rank five sub‐themes under each priority area on a five‐point scale. Responses were analyzed using Kruskal–Wallis rank tests and weighted‐average calculations. Farmers assigned the greatest weight to characterizing
A. adenophora
as a weed (weedy characteristics) (28%), followed by control methods (24%), competition (20%), growth habit (16%), and awareness (12%). Sub‐theme rankings differed significantly within each priority area (χ
2 ≥ 78.95, p < 0.001). Farmers identified the species abundance, prolific seed production, and rapid seedling growth as key drivers of its aggressive spread. They perceived
A. adenophora
as both ecologically damaging and economically harmful, prioritizing management via uprooting, burning, and burying over slashing or herbicide application. By bridging the gap in quantified farmer‐perspective data through focus group discussion, structured ranking questionnaires, and non‐parametric analysis, this study uses a participatory approach for integrated invasive‐weed management. It is replicable to similar agroecological landscapes, aligning scientific strategies with local knowledge to enhance sustainable control of
A. adenophora
to protect productivity of the farming lands.

Ageratina adenophora
's invasion across Bhutan threatens biodiversity and crop yields. This study quantifies farmers' experiential knowledge through participatory methods, revealing key concerns: aggressive spread, ecological harm, and preferred control strategies. Aligning local insights with scientific approaches supports sustainable weed management across similar agroecological landscapes.

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