Gerardo Arceo-Gómez1, Luis Abdala-Roberts2, Anneka Jankowiak1, Clare Kohler1, George A Meindl1, Carmen M Navarro-Fernández3, Víctor Parra-Tabla2, Tia-Lynn Ashman4, Conchita Alonso3. 1. 4249 Fifth Ave, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 USA. 2. Department of Tropical Ecology, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Km. 15.5 Carretera Mérida-Xtmakuil, Mérida, Yucatán, México 97000. 3. Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (EBD-CSIC). Avda. Américo Vespucio s/n, E-41092, Sevilla, Spain. 4. 4249 Fifth Ave, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 USA tia1@pitt.edu.
Abstract
PREMISE OF THE STUDY: Coflowering plants are at risk for receiving pollen from heterospecifics as well as conspecifics, yet evidence shows wide variation in the degree that heterospecific pollen transfer occurs. Evaluation of patterns and correlates of among- and within-species variation in heterospecific pollen (HP) receipt is key to understanding its importance for floral evolution and species coexistence; however, the rarity of deeply sampled multispecies comparisons has precluded such an evaluation. METHODS: We evaluated patterns of among- and within-species variation in HP load size and diversity in 19 species across three distinct plant communities. We assessed the importance of phenotypic specialization (floral phenotype), ecological specialization (contemporary visitor assemblage), and conspecific flower density as determinants of among-species variation. We present hypotheses for different accrual patterns of HP within species based on the evenness and quality of floral visitors and evaluated these by characterizing the relationship between conspecific pollen (CP) and HP receipt. KEY RESULTS: We found that within-species variation in HP receipt was greater than among-species and among-communities variation. Among species, ecological generalization emerged as the strongest driver of variation in HP receipt irrespective of phenotypic specialization. Within-species variation in HP load size and diversity was predicted most often from two CP-HP relationships (linear or exponentially decreasing), suggesting that two distinct types of plant-pollinator interactions prevail. CONCLUSIONS: Our results give important insights into the potential drivers of among- and within-species variation in HP receipt. They also highlight the value of explorations of patterns at the intraspecific level, which can ultimately shed light on plant-pollinator-mediated selection in diverse plant communities.
PREMISE OF THE STUDY: Coflowering plants are at risk for receiving pollen from heterospecifics as well as conspecifics, yet evidence shows wide variation in the degree that heterospecific pollen transfer occurs. Evaluation of patterns and correlates of among- and within-species variation in heterospecific pollen (HP) receipt is key to understanding its importance for floral evolution and species coexistence; however, the rarity of deeply sampled multispecies comparisons has precluded such an evaluation. METHODS: We evaluated patterns of among- and within-species variation in HP load size and diversity in 19 species across three distinct plant communities. We assessed the importance of phenotypic specialization (floral phenotype), ecological specialization (contemporary visitor assemblage), and conspecific flower density as determinants of among-species variation. We present hypotheses for different accrual patterns of HP within species based on the evenness and quality of floral visitors and evaluated these by characterizing the relationship between conspecific pollen (CP) and HP receipt. KEY RESULTS: We found that within-species variation in HP receipt was greater than among-species and among-communities variation. Among species, ecological generalization emerged as the strongest driver of variation in HP receipt irrespective of phenotypic specialization. Within-species variation in HP load size and diversity was predicted most often from two CP-HP relationships (linear or exponentially decreasing), suggesting that two distinct types of plant-pollinator interactions prevail. CONCLUSIONS: Our results give important insights into the potential drivers of among- and within-species variation in HP receipt. They also highlight the value of explorations of patterns at the intraspecific level, which can ultimately shed light on plant-pollinator-mediated selection in diverse plant communities.
Authors: Na Wei; Rainee L Kaczorowski; Gerardo Arceo-Gómez; Elizabeth M O'Neill; Rebecca A Hayes; Tia-Lynn Ashman Journal: Nature Date: 2021-09-08 Impact factor: 49.962