Data for analysis for the manuscript The unexpected influence of legacy conspecific density dependence

When plants die, neighbours escape competition. Living conspecifics could disproportionately benefit because they are freed from negative intraspecific processes; however, if negative effects of past conspecific neighbours persist, other species might be advantaged, and diversity maintained through legacy effects. We examined legacy effects in a mapped forest by modelling the survival of 37,212 trees of 23 species using four neighbourhood properties: living conspecific, living heterospecific, legacy conspecific (dead conspecifics), and legacy heterospecific densities. Legacy conspecific effects proved nearly four times stronger than living conspecific effects; changes in annual survival associated with legacy conspecific density were 1.5% greater than living conspecific effects. Over 90% of species were negatively impacted by legacy conspecific density compared to 47% by living conspecific density. Our results emphasize that legacies of trees alter community dynamics, revealing a significant oversight in prior research, which may have underestimated the strength of density dependence by not considering legacy effects.