Interactions in the environment can positively or negatively affect how much pollen is available for plant fertilization. These interactions may be ‘biotic’, with other living organisms, or ‘abiotic’, such as the effects of temperature or soil moisture. Both these types of interactions are affected by climate change and can impact plant reproductive fitness. A recent 4-year study, published as part of a special issue on Plant Reproduction in a Changing Global Environment in Annals of Botany has shown that these interactions currently defy prediction.
Rodelius and Iler conducted field measurements in a subalpine plant community in the Colorado Rocky Mountains of Western USA, where there is decreasing water input into soil from snowmelt. Their aim was to “understand whether the effects of pollination (biotic component) on plant reproduction depend on soil moisture (abiotic component), two factors known to affect plant reproduction and that are changing with global change.”
In their experiments, Rodelius and Iler manually added pollen and/or water to two perennial wildflower species: Nuttal’s larkspur (Delphinium nuttallianum) and Fendler’s waterleaf (Hydrophyllum fendleri). The plants wereexposed to varied soil moisture over the course of the experiments to determine whether fruit set, seeds per fruit, or seeds per plant responded. The scientists “collected fruits as they matured, counted seeds and quantified the number of fruits per flower, seeds per fruit and seeds per plant as measures of reproductive success.”
Rodelius and Iler found that seed production of both species is “resilient to changes in soil water availability”. Only fruit production for Fendler’s waterleaf was limited by pollen and this was independent of soil moisture. Nuttal’s larkspur did not respond to manual pollen or water supplementation, but did respond to interannual variation in soil moisture by increasing fruits per flower and decreasing seeds per fruit as soil moisture increased.
The results show that our understanding of biotic-abiotic interactions is not yet deep enough to accurately predict the effect of changes to plant reproduction.
READ THE ARTICLE
Rodelius, I.B. and Iler, A.M. (2025) ‘Does pollination interact with the abiotic environment to affect plant reproduction?’, Annals of Botany, 135, pp. 141-151. https://doi.org/10.1093/aob/mcae095
Image: Canva.
The post Soil moisture does not predictably affect pollination success appeared first on Botany One.
