Botanical gardens as arks for conserving pollinators and plant-pollinator interactions

 by Vilella-Arnizaut et al.

 

Botanical gardens have contributed to plant conservation in numerous ways for decades. However, little is known about the potential impact botanical gardens may have on pollinator conservation. This gap in knowledge is worth investigating since pollinator populations are experiencing global declines, partially due to habitat loss, among other factors. We are interested in understanding whether botanical gardens can function as a potential source for pollinator habitat, such as in native restoration gardens, in the hopes of aiding in the conservation of local pollinator populations.

Our study takes place in the Prairie Coteau region of South Dakota, where we sampled the plant and pollinator communities of 15 native temperate grassland remnants and 1 native grassland restoration site managed as part of a botanical garden. We compared the plant and pollinator communities to see whether the diversity of a native grassland restoration area inside a botanical garden is similar to the diversity found in remnant temperate grassland sites of the same region. We also analyzed these communities using an ecological network approach to examine how plant-pollinator communities in native temperate grasslands differ structurally from a native grassland restoration garden.

We found pollinator diversity within the botanical garden’s native grassland restoration site to be at the high end of the distribution of the remnant temperate grassland sites throughout the entire flowering season. The plant diversity and network community metrics remained similar between the two environments, except that remnant temperate grasslands had more links with pollinators than their garden counterpart. Nevertheless, these two environments did not experience much community overlap, suggesting the restoration grassland garden may demonstrate similar, or in some cases – greater diversity to native temperate grassland remnants in the same region. However, these two environments did not necessarily share the same kinds of plants and pollinators. 

Overall, our findings illustrate the promising role that native grassland restoration gardens within botanical gardens may play as refugia for local pollinator communities by supporting plant-pollinator interactions comparable to those found in native habitat remnants in the same region. Further research into this knowledge gap regarding the role of botanical gardens in pollinator conservation may help bolster current efforts to decelerate the global pollinator decline.

Read the scientific publication in JPE.