Phenological shifts and flower visitation of 185 lowland and alpine species in a lowland botanical garden

Abstract

Many plant species respond to climate change by phenological shifts, usually with an earlier flowering onset. However, the variability in flowering responses to changed climatic conditions is large, and rare plant species, which are likely to have a low environmental tolerance, may be less able to shift their phenology than common ones. If plant species respond to climate change by shifting their flowering phenology, plant-pollinator interactions may become disrupted. However, it is vital for the reproduction of animal-pollinated plants, and thus for long-term population survival, that plants can attract pollinators. This might be especially difficult for rare species as they may depend on one or few pollinator species. To assess how climatic conditions affect the phenology of common and rare plant species, and whether the plant species attract potential pollinators, we assessed flowering onset and flower visitation in the lowland Botanical Garden of Bern, Switzerland, for 185 native plant species originating from different altitudinal zones. Plants from high elevations flowered earlier and showed more pronounced phenological shifts than plants from lower elevations, independent of species rarity. The probability, number, and duration of flower visits and the number of flower-visitor groups were independent of the altitudinal zone of plant origin and of species rarity. The composition of flower-visitor groups did also not depend on the altitudinal zone of plant origin and on species rarity. Thus, rare and common alpine plants may generally respond to climate change by an earlier flowering onset, and may be able to establish novel interactions with pollinators.

Pollination networks from natural and anthropogenic-novel communities show high structural similarity

“…those formed by species that do not share a common evolutionary history (Hobbs et al 2006), is essential to evaluate community resilience and the capacity of these communities to continue to delivery key ecosystem services (Razanajatovo et al 2015;Hui et al 2016;Le Roux et al 2017). In this context, botanical gardens represent an invaluable experimental ground for comparative and community-wide studies as they host a wide range of species from different origins, growing under the same climatic and ecological conditions (Primack and Miller-Rushing 2009;Razanajatovo et al 2015Razanajatovo et al , 2018.…”

Selection for later flowering time in an orchid through frost damage and pollinator activity

“…Few studies up to now have investigated potential desynchronization between spring-flowering plants and their pollinators through climate change (Renner and Zohner, 2018). Whereas for plants with generalized pollination systems, little de-synchronization has been found (Forrest, 2015, Bartomeus et al, 2011, Forrest and Thomson, 2011, Razanajatovo et al, 2018), plants with more specialized pollination are more likely to suffer from increased mismatch between flowering and pollinator emergence. In the Japanese early-spring flowering, bumblebee-pollinated Corydalis ambigua, such a mismatch is generated when snowmelt is early but subsequent soil warming is slow, because bumblebee emergence depends on soil warming but flowering is triggered by surface warming after snowmelt.…”

Diversity and spatial distribution of native bees in Mt. Banahaw de Lucban, Philippines

“…Aside from habitat degradation, climate change is currently threatening wild pollinators, compromising their ability to provide pollination services to wild and cultivated plants (Jaffé et al, 2019). For instance, plants may shift their phenology as a response to climate change which can disrupt plant-pollinator interactions (Razanajatovo et al, 2018).…”