Potential Disruption of Pollination in a Sexually Deceptive Orchid by Climatic Change

Abstract

Warmer springs advance many phenological events, including flowering time in plants and the flight time of insects. Pollination by insects, an ecosystem service of immense economic and conservation importance, depends on synchrony between insect activity and flowering time. If plants and their pollinators show different phenological responses to climate warming, pollination could fail. Information about the effects of warming on specific plant-insect mutualisms is difficult to obtain from complex pollination networks. In contrast, the extraordinarily specific deceptions evolved by orchids that attract a very narrow range of pollinators allow direct examination of the potential for climatic warming to disrupt synchrony. Here we show that a sexually deceptive orchid and the solitary bee on which it depends for pollination will diverge in phenology with increasing spring temperature. Male bees inadvertently pollinate the orchid flowers during pseudocopulation. Analysis of museum specimens (1893-2007) and recent field-based records (1975-2009) showed that flight date of the solitary bee Andrena nigroaenea is advanced more by higher temperatures than is flowering date in the deceptive orchid Ophrys sphegodes. Male bees emerged slightly earlier than females, which attract male copulatory attentions away from the deceptive flowers. Warming by as little as 2°C increased both the probability of male flight and the proportion of females flying in the bee population before orchid flowering; this would reduce the frequency of pseudocopulation and thus lower pollination success rate in the orchid. Our results demonstrate a significant potential for coevolved plant-pollinator relationships to be disrupted by climatic warming.

Specialty fruit production in the Pacific Northwest: adaptation strategies for a changing climate

“…Pollination from both honey bees and native bees is critical for tree fruit and berry crops grown in the Pacific Northwest (Sagili and Caron 2016;Rucker et al 2012). Although, some studies have shown temporal mismatch between some flowering plants and pollinators due to climate change (Burkle et al 2013;Robbirt et al 2014), there is a knowledge gap regarding such phenological mismatches between pollinator-dependent agricultural crops and bees, and their impact on pollination (Settele et al 2016). The potential for such phonological mismatch is greater for native bees such as bumble bees that hibernate during winter and whose emergence in spring is dependent on prevailing temperatures during the hibernation period (Pyke et al 2016).…”

Thousands of microbial genomes shed light on interconnected biogeochemical processes in an aquifer system

“…Leakage is likely when ecosystem discordance arises from lags in activation of microbial community members responsible for sequential steps in a biogeochemical cycle. This is analogous to the uncoupling that occurs when climate warming causes early flowering that is out of sync with insect hatching, leading to pollination failures42. Such phenomena are little known in microbial ecosystems, but could give rise to large fluxes of climate-relevant intermediate compounds.…”

Studying plant–pollinator interactions in a changing climate: A review of approaches

“…Sampling effort for specimens is largely unknown. Thus, they represent an imperfect historical record, which researchers have nonetheless been able to successfully use, often combined with creative approaches (e.g., Bartomeus et al, 2013; Robbirt et al, 2014; Matthews and Mazer, 2015). …”