Among‐species variation in flower size determines florivory in the largest tropical wetland

Abstract

Premise: Flower damage caused by florivores often has negative consequences for plant reproduction. However, the factors affecting plant-florivore interactions are still poorly understood, especially the role of abiotic factors and interspecific variation in florivory within ecosystems. Thus, the patterns of florivory levels and its consequences for plant communities need to be investigated further. Methods: We assessed the influence of abiotic factors related to climatic seasonality, of phylogenetic relationships among plants, and of functional attributes associated with attractiveness to pollinators on florivory incidence and intensity in the Pantanal, the world's largest tropical wetland. Between December 2020 and November 2021, the percentage of flowers attacked (incidence) and petal area removed (intensity) by florivores were examined in 51 species from 25 families, considering flowering season, the substrate where the plants occur, and flower attributes as potentially determining factors on florivory levels. Results: Phylogeny and environmental factors did not have a significant influence on florivory. The only determinant of interspecific variation in florivory incidence and intensity was flower size, where larger flowers experienced higher florivory levels regardless of season and substrate, while flower arrangement and color were not significant factors. Conclusions: Our study is one of the first to estimate the community-wide effects of biotic and abiotic factors on both the incidence and the intensity of florivory. The magnitude of this plant-florivore interaction may reduce reproductive success and entail selective pressures on plant attractiveness to pollinators. K E Y W O R D S aquatic plants, dry and rainy season, flower area removed, frequency of flowers attacked, Pantanal, terrestrial plants

Effects of Florivory on Floral Visitors and Reproductive Success of Sagittaria lancifolia (Alismataceae) in a Mexican Wetland

“…Moreover, there is a greater intensity of florivory in female than in male flowers (5.58 and 3.92, respectively). In other species from aquatic environments, Ortiz et al [ 39 ] report high incidence values of florivory for Eichornia azurea (93.3%), Ludwigia lagunae (96.7%), L. tomentosa (66.7%) and Nimphae amazonium (100%), as well as in Hydrocleys parviflora (55.5%), with values close to those found in our study. Likewise, variation in the intensity of herbivory has been found in aquatic species such as Echinodorus grandiflorus (1.7%), Hydrocleys flava (9.7%), Pontederia rotundifolia (15.4%), and P. parviflora (35.5%), among others [ 39 ].…”

“…In other species from aquatic environments, Ortiz et al [ 39 ] report high incidence values of florivory for Eichornia azurea (93.3%), Ludwigia lagunae (96.7%), L. tomentosa (66.7%) and Nimphae amazonium (100%), as well as in Hydrocleys parviflora (55.5%), with values close to those found in our study. Likewise, variation in the intensity of herbivory has been found in aquatic species such as Echinodorus grandiflorus (1.7%), Hydrocleys flava (9.7%), Pontederia rotundifolia (15.4%), and P. parviflora (35.5%), among others [ 39 ]. Although there is variation in the incidence and intensity of florivory between environments and between terrestrial and aquatic species, no studies have evaluated these variables considering plant species with female and male flowers (dioecious or monoecious).…”

“…In general, a wide variation has been documented in the incidence of florivory in plants from tropical and temperate zones (0.2 to 97%) and this can be double in tropical compared to temperate regions [ 6 ]. Likewise, solitary flowers present higher frequencies of attack than inflorescences, due in part to the fact that solitary flowers are larger than those grouped in inflorescences [ 6 , 39 ]. In our study, we found an incidence of florivory of almost 50%, i.e., half of the flowers in the inflorescence of S. lancifolia presented some degree of damage.…”

Flower visitor networks: Reduced reproductive success driven by antagonists in a hummingbird‐pollinated species

“…Despite the importance and ubiquity of floral antagonists across different taxa and ecosystems, only recently pollination ecologists have increased efforts to disentangle the patterns of interaction with flowers, and the ecological and evolutionary consequences for plants (Boaventura et al, 2022;Moreira et al, 2019;Ortiz et al, 2023). Thus, deeper and more extensive studies are needed to fully understand the simultaneous impact of floral antagonists and pollinators on plant reproduction.…”