Integrating nocturnal and diurnal interactions in a Neotropical pollination network

Abstract

Plants establish pollination interactions with different groups of animals, including nocturnal ones that establish interactions with economically valuable and culturally important crops, as well as wild plants of conservation concern. Despite the considerable number of studies addressing the structure and dynamic of pollination networks, nocturnal interactions have been relatively overlooked. Using a multilayer network approach and considering diurnal and nocturnal interactions, we aimed to understand how interactions at different periods of the day are integrated and contribute to the network structural pattern. We also aimed to highlight how multilayer networks may give a more nuanced assessment of species importance across layers. We assembled a pollination network of an intensively studied Neotropical area by standardizing interaction data from 16 previous studies into a presence/absence (binary) network. Then, we used a multilayer network approach to evaluate the network modularity and plant species' roles in these different temporal layers. Plants were classified as nocturnal or diurnal according to the onset of floral opening and pollinators were classified according to their foraging period. The network consisted of 178 pollinator species and 158 plant species, with 870 links. Among plant species, 135 species have diurnal floral opening while 23 species are nocturnal. The multilayer network was significantly modular, and these modules differed in the composition of pollinator groups (e.g., hawk moths, bats, bees, hummingbirds), as well as of diurnal and nocturnal plants. We show that diurnal and nocturnal interactions are organized into interconnected modules in the multilayer network. Nocturnal plants had higher values of versatility and multidegree than diurnal plants, due to their role in connecting the two temporal layers. Synthesis. Our study highlights the importance of integrating different pollination systems to understand the importance of distinct components that structure pollination networks. We also illustrate the value of tapping into existing information, particularly species interaction data, from well‐studied biodiversity hotspot areas, to gain a better understanding of how communities are structured. Finally, despite the relative scarcity of nocturnal pollination network studies, we showed nocturnal plants, which often make complementary use of diurnal pollinators, to be important in connecting the temporal layers.

Untangling biodiversity interactions: A meta network on pollination in Earth's most diverse tropical savanna

“…In this study, we present a comprehensive ecological meta network of pollinator–plant interactions within the Brazilian Cerrado, which is recognized as the world's largest, most biodiverse, and threatened tropical savanna (Cardoso Da Silva & Bates, 2002 ). Our study reveals that the modular structure of the network aligns with findings from previous studies on partial networks in the Neotropics (Olesen et al., 2007 ; Schleuning et al., 2012 ; Souza et al., 2022 ; Vizentin‐Bugoni et al., 2018 ). Although entomophily, and particularly melittophily, is the predominant pollination syndrome in the Cerrado, other insects and vertebrates also play a crucial role in shaping the network structure.…”

“…Our study reveals that the modular structure of the network aligns with findings from previous studies on partial networks in the Neotropics (Olesen et al, 2007;Schleuning et al, 2012;Souza et al, 2022;Vizentin-Bugoni et al, 2018). Although entomophily, and particularly melittophily, is the predominant pollination syndrome in the Cerrado, other insects and vertebrates also play a crucial role in shaping the network structure.…”

“…The observed modular structure in our network appears to be a common characteristic of both natural (Maruyama et al, 2014;Olesen & Jordano, 2002;Schleuning et al, 2012;Souza et al, 2022;Vizentin-Bugoni et al, 2018) and human-dominated landscapes (Assunção et al, 2022) in the Cerrado. Modularity is expected to increase with species richness and habitat heterogeneity, which can be explained by two mechanisms that are not mutually exclusive (Olesen et al, 2007).…”

“…Although entomophily, and particularly melittophily, is the predominant pollination syndrome in the Cerrado, other insects and vertebrates also play a crucial role in shaping the network structure. Furthermore, we showed that plants in different plant physiognomies act as connectors between modules, mediating interactions between vertebrate and invertebrate species at different periods during day and night (Souza et al., 2022 ).…”

Lepidoptera proboscis pollens are mainly derived from nectar

“…In the Yunnan Province of Southwest China, the researchers identified 554 species of pollinating butterflies, and their potential pollinating service could be a great contribution to montane agriculture, which has expanding areas of cash crops and fruit horticulture (Zhang et al, 2020). Except the above spatial research, the temporal research showed that the adult Lepidoptera were often complementary to the diurnal pollinators (Singh et al, 2022; Souza et al, 2022). The adult Lepidoptera even visit more flower species than bees (Walton et al, 2020).…”