Density‐dependent dispersal strategy of pollinator moderates the adverse effect of habitat loss on plant reproduction: An integrated model based on pollinators' behavioural response

Abstract

Major challenges for plant conservation are predicting the effect of habitat loss on pollination success and plant reproduction potential. Most studies report that pollinator movement is affected by quantitative and spatial characteristics of landscapes. However, little is known about the role of pollinator movement, impacted by floral volatiles and intraspecies interaction, on plant reproduction in fragmented landscapes. To clarify the effect of pollinator movement on plant reproduction relative to habitat loss, we developed an integrated model incorporating pollinator's foraging response with its dispersal process mediated by a density‐dependent dispersal (DDD) strategy. This model performed better in capturing behaviour response of pollinators than do current methods. The integrated model was verified with field results of pollinator visitation and plant reproduction of saltcedar Tamarix chinensis inhabiting the Yellow River Delta, and then was compared against a dispersal strategy called density‐independent dispersal (DID). The model was applied to landscapes with various non‐habitat percentage (NHP) to explore the effect of habitat loss on plant reproduction. Results suggested that saltcedar populations differ in their responses to habitat loss, which depended on the spatial scales considered. At landscape scale, increasing NHP significantly inhibited dispersion extent of floral volatiles and therefore reduced pollinator visitation and subsequent seed production, especially when NHP exceeded the critical threshold of 0.6. However, at patch scale, comparing with DID strategy, the DDD strategy enabled pollinators to increase their utilization of flowers by 43.42% and 6.79% in low‐density and distant plant patches, whereas their utilization was reduced by 7.75% and 2.24% in high‐density and central patches, respectively. Plant reproduction was improved correspondingly in low‐density and distant patches under different NHPs. Consequently, habitat loss inhibits the volatile dispersion and interferes the foraging success of pollinators, a major factor influencing plant reproduction at landscape scale. At patch scale, adaptive utilization of pollinators exhibiting DDD strategy alleviates the negative effect of habitat loss on plant production, and maintain plant population persistence. Since pollinator behavioural response is critical to plant reproduction, we recommend the use of the here presented integrated model to assess the impact of habitat loss on plant reproduction. Read the free Plain Language Summary for this article on the Journal blog.

Study methodology impacts density-dependent dispersal observations: a systematic review

“…Studies often refer to density to explain other findings related to movement without having actual density measurements to test the direct correlation between density and dispersive movements (e.g., [ 15 , 48 , 82 ]). Similarly, certain studies also use dispersal to justify their results for density or abundance, again without obtaining measurements for dispersive movements (e.g., [ 63 ]).…”

The Development of Floral Scent Research: A Comprehensive Bibliometric Analysis (1987–2022)

“…These pollination systems can exhibit specialization [4,5] or generality [6,7], and the release of FSs is intricately regulated by a host of biotic or abiotic factors [8], ranging from drought stress [9] to temperature [10], profoundly influencing a flower's allure to pollinators. Notably, the ramifications of habitat loss affect plant-pollinator dynamics, with direct consequences for plant reproduction [11] and thus relate to the functional areas of ecosystems [12]. The evolution of practical methodologies and affordable instrumentation for collecting, separating, and identifying volatile compounds [13][14][15] has solidified FS research as a cornerstone in scientific inquiry.…”