Diversifying agroecological systems: Plant-pollinator network organisation and landscape heterogeneity matter

ASTEGIANO, JULIA; CARBONE, LUCAS; ZAMUDIO, FERNANDO; TAVELLA, JULIA; ASHWORTH, LORENA; AGUILAR, RAMIRO; BECCACECE, HERNÁN M.; MULIERI, PABLO R.; NOLASCO, MIGUEL; TORRETTA, JUAN PABLO; CALVIÑO, ANA

AGRICULTURE, ECOSYSTEMS AND ENVIRONMENT

ELSEVIER SCIENCE BV

Año: 2024 vol. 361

0167-8809

Agroecologyis a process-based agriculture that implements agrobiodiversification tostabilize ecosystem processes and crop yield, leading to sustainable foodsystems. Traditionally, agrobiodiversification focused on increasingwithin-farm plant richness, which may increase local species richness of highertrophic levels. However, it is increasingly recognized that stabilizingecosystem processes involving plant-animal interactions -e.g., pollination-requires practices that consider the organisation of interactions andheterogeneity effects at landscape level. In this work, we investigated howplant-pollinator interactions organised in agricultural landscapes harbouringagroecological farms and how landscape heterogeneity modulated interactionsorganisation. We characterized the organisation of 36 plant-pollinator networksdescribing interactions in nine agricultural landscapes -i.e., agroecologicalfarms and their surroundings- across four flowering peak periods in theAgri-food region of central Cordoba, Argentina. We evaluated (1) centrality tonetwork organisation of plant and pollinator only registered interacting inagroecological farms, farm surroundings (unique species) or in both locations (sharedspecies); and (2) network organisation across gradients of landscapeconfigurational (mean edge density) and compositional (forest proportion)heterogeneity. We found that plant-pollinator networks at landscape scale showednested structures. Shared plant and pollinator species were the lessrepresented in such networks but were central to networks organisation, i.e.,they were connected to most species and with the highest frequency. Resultsalso showed that network organisation changed with landscape configurationalheterogeneity. Higher landscape mean edge density was associated with highertotal and unique plant richness in networks and lower richness of sharedplants. Network connectance and nestedness decreased with higher landscape meanedge density, i.e., plant and pollinator species interacted with less species,shared less interaction partners with more specialist species and showed lowerinteraction frequency with generalist partners in more heterogeneous landscapes.Our study showed that in agricultural landscapes harbouring agroecologicalfarms (1) a few species inhabiting and showing interactions in bothagroecological farms and their surroundings are key to the orga[1]nisation ofplant-pollinator interactions, and (2) landscape heterogeneity modulates suchorganisation. As interaction networks dynamic is influenced by networkorganisation, landscape configurational heterogeneity may modulate thestability of the pollination process and ultimately agroecological production.Thus, the agrobiodiversification of agroecological systems may benefit fromconsidering the complexity of plant-pollinator interdependencies acrossagricultural landscapes and the effects of landscape heterogeneity on suchcomplexity.