<b>Below-ground storage organ morphology mediates resource allocation and climate adaptation strategies in ephemeral desert plants</b>

Desert perennials must strategically allocate limited resources between survival and reproduction under highly variable climatic conditions. Below-ground storage organs (BSOs) are critical adaptive structures, but how to influence life-history strategies remains poorly understood. We investigated how contrasting below-ground storage organ (bulb vs. tuber) mediates resource allocation strategies in desert environments.Over a seven-year field experiment (2017–2023) in the Gurbantunggut desert, we compared phenology, biomass allocation, nutrient storage thresholds, and reproductive output between bulb <i>Allium pallasii</i> and tuber <i>Eremurus inderiensis</i> under pronounced climatic fluctuations.<i>A. pallasii </i>demonstrated an opportunistic, ‘fast’ life-history strategy, marked by early reproduction at low nutrient reserves (~0.7 mg N, approximately 3-fold accumulation), moderate seed output (20 –50 seeds/plant), and drought avoidance through early dormancy. In contrast, <i>E. inderiensis</i> adopted a conservative ‘slow’ strategy, characterized by substantial biomass investment in tuber, delayed reproduction at high nutrient thresholds (~20 mg N, approximately 185-fold accumulation), drought tolerance, and high seed production (&gt;300 seeds/plant).These findings confirm that BSO morphology drives distinct bet-hedging strategies in desert perennials, and highlight that BSOs intensify contrasting adaptive strategies, shaping species-specific trade-offs between reproduction timing, resource investment, and drought resilience, with significant implications for understanding perennial plant adaptation under climate variability.