Time since fire strongly and variously influences anthophilous insects in a fire‐prone landscape

Abstract

Drivers of species productivity and ecosystem function are of great ecological significance. In fire‐prone ecosystems, dispersion patterns of important pollinator species are driven by the various fire events over space and time. However, different species have varying responses to fire intensity and frequency. Here, we assess how time since last fire influences abundance, composition, and dispersion patterns of flowering plants and anthophiles in a highly fire‐prone landscape. We classified study area into age since last fire, which were <1 yr (short‐term burned), 2–3 yr (medium‐term burned), and 9–10 yr (long‐term burned). We collected insect anthophiles using yellow, blue, and white pan traps at sites established in each post‐fire class. We also estimated flower abundance at each study site. Overall, anthophile abundance was highest in medium‐term burned, while lowest in short‐term burned sites. Also, flower abundance was highest at medium‐term burned and lowest in long‐term burned sites. Species composition of flowering plants and anthophiles, especially bees and flies, differed significantly across post‐fire class. Overall, flower abundance had a significant positive effect on bee abundance. Of all the taxa, bees were the only group that showed dispersion patterns reflecting those of flower abundance. Other factors, especially requirements for other resources such as logs, drive the distribution of other anthophile taxa, especially flies. We conclude that fire drives the distribution patterns of bees through its direct effect on flower abundance and composition in a fire‐prone landscape. While high frequency of short‐term fire may reduce flower abundance, flower‐rich areas with moderate time since fire may increase diversity of anthophiles in this fire‐prone landscape.

Fire and landscape context shape plant and butterfly diversity in a South African shrubland

“…Similar to previous studies of fire ecology and invertebrates (e.g. Adedoja et al., 2019), the interpretation of our findings may be limited given the potential influence of other environmental factors. For example, the sites of different fire ages were not randomly distributed throughout the landscape and surrounding land use, soil types and microclimate were not controlled for.…”

“…For optimal plant regeneration and removal of dominant shrub, it is recommended that renosterveld patches are burned approximately every 10–15 years (Esler et al., 2014; Kraaij & van Wilgen, 2014). Limited understanding of insect ecology in renosterveld (Topp & Loos, 2019a) makes it difficult to assess how fire regimes may impact insect diversity in the fynbos biome (Procheş & Cowling, 2006), although it has been shown that bees may benefit from flower abundance resulting from regular burns in the CFR (Adedoja et al., 2019) and ecologically appropriate fire management is key to support diverse butterfly populations elsewhere in South Africa (Gaigher et al., 2019). Given the importance of understanding management impacts and ecological processes in renosterveld (Topp & Loos, 2019a) and the inclusion of habitat and landscape conservation as key strategies for butterfly conservation in South Africa (Edge & Mecenero, 2015), our intention was therefore to investigate the relationship between fire in renosterveld and butterfly diversity in the CFR.…”

Proximity to natural habitat and flower plantings increases insect populations and pollination services in South African apple orchards

“…This exposes the industry to a substantial risk in a system where the bee keeping is already under stress (Pirk et al., 2014). Habitat loss caused by climate change, the increasing frequency of fires and eucalyptus removal reduces important foraging resources for wild and managed bees throughout the year (Adedoja et al., 2019; De Lange et al., 2013), and pathogens and diseases are known stressors for bee keepers (Allsopp, 2004). Increasing managed pollinator efficiency through the augmentation of in‐farm floral resources could reduce the number of hives required per unit area of orchard.…”

Open habitats in a tropical biodiversity hotspot support pollinator diversity in both protected and unprotected areas

“…Flowering plant composition showed a significant association with the composition of insect pollinators in both savanna and rain forest vegetation zones. This underscores the key role that flowering plants play in driving insect pollinator diversity in the tropics (Adedoja & Kehinde, 2018; Stein et al, 2018), as well as in other areas (Adedoja et al, 2019; Geslina et al, 2016). While flowering plant species richness and abundance is well known to influence pollinator diversity (Adedoja et al, 2019; Stein et al, 2018), we show here that the species composition of flowering plants is critical for the distribution of insect pollinators in both PAs and unprotected areas.…”

“…This underscores the key role that flowering plants play in driving insect pollinator diversity in the tropics (Adedoja & Kehinde, 2018; Stein et al, 2018), as well as in other areas (Adedoja et al, 2019; Geslina et al, 2016). While flowering plant species richness and abundance is well known to influence pollinator diversity (Adedoja et al, 2019; Stein et al, 2018), we show here that the species composition of flowering plants is critical for the distribution of insect pollinators in both PAs and unprotected areas. Some species‐specific requirements of different pollinators may influence their distribution across ecosystems with various traits of flowering plants.…”