Bearing Fruit: Possible Trade-Offs in Black Rasberry Fruit Behavior

Abstract

Black raspberry (Rubus occidentalis) has recently been highlighted in numerous research studies for its purported health benefits, its market potential as a crop, and its role in native ecosystems. However, we currently understand little about where the species grows and fruits best, how variable its fruiting behavior is, and how its fruit behaviors are influenced by its environment. I compared light, soil pH, soil organic matter, soil texture, and soil nitrogen measurements with data from fruits harvested from 49 black raspberry stands in southeastern Michigan. Linear mixed-effect regressions (LMERs) were used to determine whether any fruit traits show significant relationships with any of these environmental factors. My data suggest black raspberry is a very tolerant species; its ecological role may be broader than originally thought. The plant’s fruit traits appear to be highly variable, and this flexibility may have adaptive significance. Canes were significantly more likely to successfully fruit in environments with higher midday light availability and in environments with more neutral, more finely-textured, and less organic matter-rich soils. Light availability and soil texture were strongly positively correlated with fruits and fruit mass produced, and soil texture was also significantly correlated with a taller and narrower average fruit shape and higher average water content. My research suggests that fruiting success may be the most appropriate metric to use when characterizing a fruiting plant’s niche. Also, black raspberry appears well-suited for use as a model organism to study life-history ecology in angiosperms.