In our new post, Professor Tao Sun—from the School of Environment, Beijing Normal University, China—presents his latest work ‘Density-dependent dispersal strategy of pollinator moderates the adverse effect of habitat loss on plant reproduction: An integrated model based on pollinators’ behavioural response’. He discusses the importance of looking at details to understand animal behavior, shows the development of his model, and elucidates his research interest in coastal ecosystems.   

About the paper

Most flowering plants need pollinators (e.g. bees, butterflies, hoverflies) to transfer pollen; however, pollination processes are being negatively affected by anthropogenic alterations such as habitat loss. Changes in the quantitative and spatial characteristics of landscapes will hinder pollinator foraging capacity, such as responses to flower scents and behavioral movement between plant patches. At present, there are some excellent works that study the effect of foraging response and movement dispersal of pollinators on plant reproduction. However, adaptive dispersal strategy—resulting from the intraspecific relationship of pollinator individuals—is often overlooked when formulating forecasts of plant reproduction response to habitat loss. Since the foraging response and movement dispersal of pollinators are two key stages in the whole pollination process, we decided to investigate whether there is a way to integrate the two stages together to answer the following question: What are the foraging responses and adaptive movement strategies of pollinators, and what are their effects on plant reproduction within a heterogeneous landscape?

Our ongoing work will provide a theoretical framework for exploring foraging behaviors and dispersal processes of pollinators which, together, should improve our understanding of how plant-pollinator interactions respond to habitat loss. In our simulation results, we were particularly excited to see that the visitation rate of pollinators which exhibited a density-dependent dispersal strategy—in plant patches with low density and high sparsity—was higher than expected. This study also suggests that the positive role of plant-pollinator interactions in promoting plant reproduction should be considered when carrying out vegetation restoration, since facilitating plant reproduction may help improve restoration efficiency or promote restoration efforts.

About the research

In this research, an integrated model was developed by incorporating pollinator’s foraging response with its density-dependent dispersal process. This integrated model involved two key stages of the pollination process, including a foraging response stage of pollinators mediated by the diffusion of floral volatiles, and an individual dispersal stage mediated by the density-dependent dispersal strategy of pollinators. This model was verified in the saltcedar (Tamarix chinensis) inhabiting the Yellow River Delta and also was applied to a series of landscapes with different habitat loss scenarios.

The primary motivation for this paper was to explore the effect of habitat loss—mediated by the foraging response and dispersal strategy of pollinators—on plant reproduction. Surprisingly, there were some unexpected results when working on this study. First, our simulation results suggest that we need to pay particular attention to changes in local microclimates (e.g., wind speed, temperature, and humidity), rather than just assessing changes in quantitative and spatial characteristics of plant patches. This is because these local microclimate changes could alter the dispersion of floral scents and the subsequent foraging success of pollinators. Another point worthy of attention is the critical threshold effect of habitat loss—beyond which the foraging success rate of pollinators declines abruptly. This reminds us that the extent of habitat loss must to be considered at an early stage and effective measures should be taken in a timely manner.

The factors that influence pollinator migration between plant patches were simplified in our integrated model in terms of pollinator movement rules. In the real-life ecosystem, many factors would significantly affect the movement behavior of pollinators in the context of habitat loss, such as: microclimatic factors; predation risk; local environmental factors; landscape connectivity; etc. Therefore, future research priorities should focus on how pollinators respond to local environmental changes due to habitat loss, and how pollinators distribute themselves spatially when faced with increasing external risks from predators and suboptimal habitat.

About the author

I am a Professor at the School of Environment, Beijing Normal University, China. My research interest is in the hydroecological processes of coastal ecosystems. I am fascinated by the various biological characteristics of species, and incredible worlds that these species inhabit. What interests me most is the mechanisms and simulation of nonlinear-response processes in coastal ecosystems under multifactorial stress. I am very interested in how species organize themselves in this complicated ecosystem and how they adapt to the changeable environment through intra-/interspecific interaction and feedbacks. In the past several years, I have tried to interpret the inter-species competition-facilitation relationship conversion process under environmental stress in order to construct a spatial population dynamic model with hydrological and ecological connectivity. I hope that this will help us to understand the underlying mechanisms behind the stability of coastal ecosystems. I am excited by the idea of improving our understanding of the interaction and feedback between organisms and the environment.

Enjoyed the blogpost? Read the research here!