Semi-natural habitats in landscapes modified the resilience of pollination to secure squash pollination.

Abstract

Ecological theory predicts that resilience of pollination can maintain crop pollination at an acceptable level, yet empirical evidence supporting the prediction still remains limited. This study combined field observations and simulated datasets to assess whether the resilience of pollination exists in agricultural ecosystems and to what extent it can maintain crop pollination. Fourteen squash (Cucurbita pepo L.) fields along a gradient of semi-natural habitats were selected in Kunming, Yunnan Province, China. Pollinator abundance and visitation density were sampled in 2020 and 2021. The resilience of pollination was quantified as the increase in pollen deposition by honey bees following experimental exclusion of bumble bees. Codes were developed to simulate the amount of pollen grains deposited by honey bees and bumble bees respectively. Results showed that bumble bee abundance increased significantly with semi-natural habitats, while honey bee abundance remained stable. Bumble bee exclusion resulted in a significant increase in honey bee visitation density. The proportion of semi-natural habitats significantly positively influenced the resilience of pollination. Furthermore, the resilience of pollination maintained squash pollination to 1,200 pollen grains per flower, thereby securing squash pollination. In conclusion, semi-natural habitats can enhance the resilience of squash pollination at an acceptable level in agricultural landscapes.