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PremiseGenetically diverse sibships are thought to increase parental fitness through a reduction in the intensity of sib competition, and through increased opportunities for seedling establishment in spatially or temporally heterogeneous environments. Nearly all research on mate diversity in flowering plants has focused on the number of fathers siring seeds within a fruit or on a maternal plant. Yet as hermaphrodites, plants can also accrue mate diversity by siring offspring on several pollen recipients in a population. Here we explore whether mate composition overlaps between the dual sex functions, and discuss the implications for plant reproductive success. MethodsWe established an experimental population of 49Mimulus ringens(monkeyflower) plants, each trimmed to a single flower. Following pollination by wild bees, we quantified mate composition for each flower through both paternal and maternal function. Parentage was successfully assigned to 240 progeny, 98% of the sampled seeds. ResultsComparison of mate composition between male and female function revealed high mate diversity, with almost no outcross mates shared between the two sexual functions of the same flower. ConclusionsDual sex roles contribute to a near doubling of mate diversity in our experimental population ofMimulus ringens. This finding may help explain the maintenance of hermaphroditism under conditions that would otherwise favor the evolution of separate sexes. 

Abstract Background Siring success plays a key role in plant evolution and reproductive ecology, and variation among individuals creates an opportunity for selection to act. Differences in male reproductive success can be caused by processes that occur during two stages, the pollination and post-pollination phases of reproduction. In the pollination phase, heritable variation in floral traits and floral display affect pollinator visitation patterns, which in turn affect variation among plants in the amount of pollen exported and deposited on recipient stigmas. In the post-pollination phase, differences among individuals in pollen grain germination success and pollen tube growth may cause realized paternity to differ from patterns of pollen receipt. The maternal plant can also preferentially provision some developing seeds or fruits to further alter variation in siring success. Scope In this review, we describe studies that advance our understanding of the dynamics of the pollination and post-pollination phases, focusing on how variation in male fitness changes in response to pollen limitation. We then explore the interplay between pollination and post-pollination success, and how these processes respond to ecological factors such as pollination intensity. We also identify pressing questions at the intersection of pollination and paternity and describe novel experimental approaches to elucidate the relative importance of pollination and post-pollination factors in determining male reproductive success. Conclusions The relative contribution of pollination and post-pollination processes to variation in male reproductive success may not be constant, but rather may vary with pollination intensity. Studies that quantify the effects of pollination and post-pollination phases in concert will be especially valuable as they will enable researchers to more fully understand the ecological conditions influencing male reproductive success. 

Nature field trips offer opportunities for urban students’ exploration, discovery, and learning which they may not experience otherwise. Seventh grade students at an economically disadvantaged urban school in the US Midwest sorted statements related to school, nature, and science before and after their field trip experience. These sorts provide a snapshot of students’ subjective thoughts on the topic. The statements were developed from student writings from the previous year’s 7th grade field trip. As a qualitatively focused mixed method, Q methodology [Q] requires only a relatively small group of participants (here just under 50). The sorts were then statistically grouped based on similarity of the sorts with the resulting three perspectives: Active Nature Learners, Not a Nature Lover, and The Environmentalists. Thus, Q provided differentiation of student views about nature before and after the field trip. Thirty-percent of those who provided sorts before and after the field trip changed their viewpoint to one that was more positive about nature (Active Nature Learners) or the environment (The Environmentalists). Students’ written comments and the descriptive viewpoints stakeholder feedback that can be used for program improvement. For instance, The Environmentalists view provides an outcome goal for the field trip experience for students.