Rare events of massive plant reproductive investment lead to long-term density-dependent reproductive success

1. The level of reproductive investment and density and distance dependent (DDD) processes are major determinants of plant reproductive output. The reproductive investment of a plant population varies temporally, but whether and how density- and distance-dependent processes are affected by population-level reproductive investment is a puzzle. 2. We used a spatially explicit approach in order to examine DDD effects on Sorbus acuparia crop sizes for a continuous period of 16 years. Our special interest was to investigate whether and how DDD processes affect long-term individual plant reproductive success (PRS) and whether such processes vary between years of relatively high and low population-level reproductive investment, measured as fruit crop size. 3. Our study revealed that DDD processes of fruit crop relate to population level reproductive investment. In most years, including all years with low and most years with moderate reproductive investment, no positive or negative DDD was foun...