Diversity matters: Effects of density compensation in pollination service during rainfall shift

Abstract

Extreme weather events are increasing in frequency due to the warming climate. Such extremities can jeopardize ecosystem services and create economic imbalances. Tropical developing countries are predicted to suffer the maximum consequences of such events. We examined the impact of such an event—extreme rainfall fluctuation—on a critical ecosystem service—pollination, which can be intricately linked to a country's economy. We performed this study in a dominant peri‐urban vegetable hub of an agriculture‐dependent developing country. We found that the yield of all pollinator‐dependent crops grown across a large spatial scale (district) over multiple years (six) drastically declined with the decrease in rainfall. At the local scale, we found that the dominant crop (representative horticultural crop) had a significant drop in yield during drought, likely due to the production of fewer female flowers and a significant shift in the pollinator community. We found that Trigona sp. (one of the four pollinators) was the critical pollinator positively influencing fruit‐to‐flower ratio (FFR) (an indicator of pollination service) in the normal rainfall year. However, despite its sharp decline during drought, the FFR remained unaffected. We found that during drought, Apis dorsata was crucial in maintaining FFR and compensated for the decline of the critical pollinator across 67% farmlands. Our study demonstrates the role of ecosystem stabilizing mechanism rescuing the crucial ecosystem service during climatic variability over the temporal scale.

A hard day’s night: Patterns in the diurnal and nocturnal foraging behavior of Apis dorsata across lunar cycles and seasons

“…Each colony consists of a single queen, a large number of workers, and a substantial but variable number of males (drones) during the swarming season. As foragers, the workers are ecological generalists and exploit a wide variety of floral species for nectar and pollen [46,47]. Recruitment to food relies upon the dance language, similar to that of the Western honey bee, A. mellifera [48].…”

Temporal and spatial foraging patterns of three Asian honey bee species in Bangalore, India

“…While attention has been paid to the tropical bee communities of Asia (Oldroyd and Wongsiri 2006;Koeniger et al 2010;Hepburn and Radloff 2011), which differ markedly from those of the Neotropics, there is much that is still unknown. Pollination services in the Neotropics are provided by a large number of solitary bee species in addition to a diverse biota of highly social stingless bee species, whereas pollination by social bees in the Old World tropics is often dominated by honey bee species in the genus Apis , one species of which (Apis dorsata ) can migrate seasonally and thus rapidly increase in number when resources become available in a given habitat (Roubik 1990;Dyer and Seeley 1994;Liow et al 2001;Oldroyd and Wongsiri 2006;Stewart et al 2018;Mukherjee et al 2019). The diversity of solitary and stingless bee species is reduced in the Asian tropics (Michener 1979;Corlett 2004), possibly in part because of the competitive advantage honey bees possess through their powerful dance communication system and through the additional benefits that eusociality provides over solitary bees (Dyer 2002;Dornhaus et al 2006;Kohl et al 2020).…”

Agrometeorological models to forecast açaí (Euterpe oleracea Mart.) yield in the Eastern Amazon

“…Pollinator dependent crops, such as açaí, can also be compromised by climate variability due to direct effects on the pollinator community . Abiotic environmental factors such as rainfall therefore jointly affect the yield and availability of pollen and nectar, and thus influence the success of pollination . Therefore, low yield values during these months could be related to stages of inflorescence and flowering since, during February and March the high rainfall could have made insect visits to flowers difficult, which consequently would impact fertilization of the flowers.…”