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<p>Shifting cultivation, commonly known as <i>jhum</i>, continues to influence the ecological fabric of Northeast India, one of the most biodiverse regions of the Indo-Burma hotspot. Over the past two decades, rapid demographic changes, policy interventions, and climate variability have shortened fallow periods (from 20–30&#xa0;years previously to &lt; 5&#xa0;years now), disrupting the ecological balance of forest–fallow mosaics. This review systematically compiles findings from peer-reviewed studies published between 2008 and 2025 to assess the ecological and environmental impacts of swidden agriculture across the eight states of Northeast India. A total of 286 studies were screened, and 160 met the inclusion criteria, focusing on quantitative ecological metrics. The analysis includes outcomes on carbon and vegetation recovery, biodiversity responses, soil and nutrient dynamics, hydrological processes, and fire regimes. Results show that shortened fallows (&lt; 7&#xa0;years) hinder complete carbon and nutrient recovery, with soil organic carbon (SOC) levels ranging from 16–18&#xa0;Mg C ha⁻<sup>1</sup> in early fallows to 70–83&#xa0;Mg C ha⁻<sup>1</sup> in 15-year-old regenerations. Above-ground biomass typically recovers only 30–60% of mature forest levels. While species richness increases along successional gradients, it remains 25–50% lower than in old-growth forests even after 20&#xa0;years. Nutrient losses after burning are swift: SOC and total nitrogen decline by 15–25%, and recovery can take up to two decades. Fire frequency and erosion rates increase sharply under shorter fallow cycles, heightening the risk of land degradation. This review highlights the ecological vulnerability of shortened swidden systems while emphasising their potential resilience with longer fallows and diversified agroforestry practices. Policy suggestions include supporting community-led forest restoration, incorporating remote sensing into land-use planning, and fostering incentive schemes like REDD + to balance livelihoods and ecological sustainability.</p>

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Ecological analysis of shifting cultivation (jhum) in Northeast India: Challenges and opportunities

  • 期刊论文

  • 发表日期：

    2026年5月12日

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  • Shri Kant Tripathi,
  • Rajdeep Chanda,
  • Salam Suresh Singh,
  • Ningthoujam Ranjana Devi,
  • Ramtharmawi,
  • Khoisnam Vramari Devi,
  • Basanta Moirangthem,
  • Remei Kaguijenliu,
  • Keshav Kumar Upadhyay,
  • Ayushi Tyagi

摘要

Shifting cultivation, commonly known as jhum, continues to influence the ecological fabric of Northeast India, one of the most biodiverse regions of the Indo-Burma hotspot. Over the past two decades, rapid demographic changes, policy interventions, and climate variability have shortened fallow periods (from 20–30 years previously to < 5 years now), disrupting the ecological balance of forest–fallow mosaics. This review systematically compiles findings from peer-reviewed studies published between 2008 and 2025 to assess the ecological and environmental impacts of swidden agriculture across the eight states of Northeast India. A total of 286 studies were screened, and 160 met the inclusion criteria, focusing on quantitative ecological metrics. The analysis includes outcomes on carbon and vegetation recovery, biodiversity responses, soil and nutrient dynamics, hydrological processes, and fire regimes. Results show that shortened fallows (< 7 years) hinder complete carbon and nutrient recovery, with soil organic carbon (SOC) levels ranging from 16–18 Mg C ha⁻1 in early fallows to 70–83 Mg C ha⁻1 in 15-year-old regenerations. Above-ground biomass typically recovers only 30–60% of mature forest levels. While species richness increases along successional gradients, it remains 25–50% lower than in old-growth forests even after 20 years. Nutrient losses after burning are swift: SOC and total nitrogen decline by 15–25%, and recovery can take up to two decades. Fire frequency and erosion rates increase sharply under shorter fallow cycles, heightening the risk of land degradation. This review highlights the ecological vulnerability of shortened swidden systems while emphasising their potential resilience with longer fallows and diversified agroforestry practices. Policy suggestions include supporting community-led forest restoration, incorporating remote sensing into land-use planning, and fostering incentive schemes like REDD + to balance livelihoods and ecological sustainability.