Species conservation under future climate change: the case of Bombus bellicosus, a potentially threatened South American bumblebee species

Abstract

Bees ensure 35 % of global food production, but this service is endangered due to several threats. Declines in bumblebee populations (genus Bombus) have been reported worldwide. Bombus bellicosus is one of the rare cases of reported threatened bumblebees in South America. It was once widespread in southern Brazil's grasslands until the 1960s. During that time, that area underwent increasing land use which led to a decrease in bee abundance and richness, and to local disappearance of B. bellicosus. Climate change is also believed to cause declines in the abundance of B. bellicosus. Here we used species distribution models to assess potential effects of climate changes on the distribution of B. bellicosus in southern Brazil, considering both current and future climate scenarios. Our results show that the suitable climatic conditions for B. bellicosus will retreat southwards. A wax cover inside its nests is usually related to Bombus species inhabiting cooler climates. This cover enables the maintenance of higher temperatures inside the nest and may be deleterious for the species under future warmer climates. Continuously growing land use is the second major threat to this pollinator. The results presented here may eventually provide theoretical grounds and enable practical conservation actions for B. bellicosus protection in South America, especially given the potential adverse effects of climate changes for this species.

Range increase of a Neotropical orchid bee under future scenarios of climate change

“…nigrita are highly plausible across a range of climatic scenarios. We discuss bionomic features of this species that may be responsible for its predicted robust response to climate change, in contrast with extensive range contractions predicted for other bees (Giannini et al 2012;Rasmont et al 2015;Martins et al 2015).…”

“…Although previous studies using SDMs already showed that the range sizes of some South American bees from the genera Melipona, Centris, Xylocopa, and Bombus (Giannini et al 2012(Giannini et al , 2013Martins et al 2015) may decrease their range sizes in response to future climate changes, such negative responses may not be general. Certain habitat generalist species, especially thermophiles, may benefit from future climate change, expanding their range to currently unsuitable areas.…”

“…The ability of organisms to adapt to climatic change is crucial with respect to maintenance of overall biodiversity and ecosystem services under future climate change of uncertain magnitude (Hughes and Hughes 2000). Considering broad-scale macroecological perspectives, changes in species distribution are expected to occur towards higher altitudes and latitudes (Parmesan and Yohe 2003;Thomas et al 2004;Parmesan 2006), and this has been shown for European (Rasmont et al 2015) and South American (Martins et al 2015) bumble bees, many of which are predicted to experience severe range contractions even under optimistic projections of limited climate change. Massive and abrupt distributional changes are expected to disrupt old species interactions (e.g.…”

Nesting biology and potential distribution of an oil-collecting Centridine Bee from South America

“…We georeferenced the localities using the point-radius method (Wieczorek et al 2004). The methods we used were described elsewhere in previous studies (i.e., Silva et al 2014aSilva et al , b, 2015Martins et al 2015). Briefly, we applied a principal components analysis to the 19 variables from Worldclim to generate 19 orthogonal principal components (PCs hereon; Table S1, supplementary material), from which we considered the first 4 (∼90 % of the original climatic variation) to predict the distribution for C. merrillae .…”

New records reveal rapid geographic expansion of Bombus terrestris Linnaeus, 1758 (Hymenoptera: Apidae), an invasive species in Argentina

“…A recent study shows that the suitable climatic conditions for another South American temperate bumblebee species (B. bellicosus) will retreat southwards under future climate scenarios (Martins et al 2014). Although climate warming might play a role in the southward retraction of B. dahlbomii (Morales et al 2013), this alone cannot explain the speed and timing of the species collapse.…”