Vegetation recovery following disturbance removal revealed forest-grassland alternative stable states in a tropical dry forest of central India

Village relocations from protected areas provide natural experiments for understanding forest recovery dynamics. We investigated vegetation recovery across 14 villages relocated from Panna Tiger Reserve, India, spanning 8-30 years post-relocation, to test whether recovery follows classical successional trajectories or diverges into alternative stable states. Using 198 plots, we surveyed trees, seedlings, saplings, shrubs, herbs, grasses, and invasive species, and compared communities with adjacent buffer forest. Contrary to succession theory predictions, time since relocation had no significant effect on woody vegetation recovery (p = 0.607). Instead, landscape position determined recovery trajectory: all riverine villages (n = 7) achieved forest state while all interior villages (n = 7) remained grassland, regardless of time elapsed. Riverine sites supported 4.7 times higher seedling abundance and 2.5 times higher sapling abundance than interior sites. Beta diversity partitioning revealed turnover-dominated differentiation (>92%) rather than nestedness, indicating species replacement between states rather than progressive accumulation. NMDS ordination showed discrete forest-grassland clusters, and indicator species analysis identified state-specific assemblages: fire-adapted Themeda-Heteropogon grasses dominated grassland while shade-tolerant Dichanthium-Oplismenus characterized forest state. Critically, seedling-to-tree ratios were identical between states (10.1 vs 10.3), demonstrating that recruitment limitation occurs post-germination rather than at seed dispersal. Invasive species declined autonomously (10.4%/year, p = 0.008), suggesting competitive exclusion by native grasses. These findings demonstrate that grass-fire feedbacks maintain alternative stable states, with landscape position determining initial trajectory. Passive restoration is insufficient for interior sites; active intervention breaking grass-fire feedbacks is required. Village relocation alone does not guarantee forest recovery as outcome depends fundamentally on landscape context.