Effects of landscape cover and local habitat characteristics on visiting bees in tropical orchards

Abstract

1 Global population declines of insect pollinators highlight the need for a greater ecological understanding of the responses of wild pollinators to local management actions and to human alterations of landscapes, especially in the tropics where crops are highly dependent on wild pollinators. 2 We examined the effects of local and landscape factors on the richness and abundance of bees in farms around Bangkok, Thailand. Bee communities in 24 mango (Mangifera indica L.) orchards in heavily modified landscapes (61-99% anthropogenic land cover) were compared. We predicted that bees would be more species rich in orchards with higher flower diversity, whereas small-sized bees with non-eusocial and/or below-ground nesting habits would be more sensitive to human disturbance, and hence rare. 3 Twenty-eight species were caught and individuals of genus Apis comprised >92% of 3842 bees sampled and dominated all 24 sites. 4 Habitat effects on bee richness and abundance were stronger at the farm scale than at the landscape scale. At the farm scale, total bee richness and abundance, as well as small, non-eusocial and below-ground nesting bee richness and abundance, were negatively associated with field size and positively associated with flowering plant diversity. The percentage of urban land cover within a 1-km radius was weakly but positively related to total bee richness and small-sized bee richness; total bee abundance was positively associated with wetland cover. 5 A greater diversity of flowering plants retained in smaller fields maintained higher bee richness and abundances, particularly small-sized bees. Farmers can enhance bee populations by maintaining small patches of flowers in their fields.

Japanese Honeybees (Apis Cerana Japonica Radoszkowski, 1877) May Be Resilient to Land Use Change

“…Our findings may show that JHB may be successfully exploiting the diverse nectar sources available to them in these environments. This may suggest that Japanese urban landscapes are not as detrimental to JHB as western urban environments are to WHB, as found in existing studies that have explored the impact of urban environments on pollen forage and pollinator health [43,61,62]. Few studies have explicitly studied the link between landscape "quality" and nectar foraging as has been attempted in our study.…”

Japanese Honeybees (Apis cerana japonica Radoszkowski, 1877) May Be Resilient to Land Use Change

“…Our findings may show that Japanese honeybee could be successfully exploiting the diverse nectar sources available to them in these environments. This may suggest that Japanese urban landscapes are not as detrimental to Japanese honeybee as western urban environments are to Western honeybee, as found in existing studies that have explored the impact of urban environments on pollen forage and pollinator health [50,62,63]. Few studies have explicitly studied the link between landscape "quality" and nectar foraging as has been attempted in our study.…”

Impact of human disturbance on bee pollinator communities in savanna and agricultural sites in Burkina Faso, West Africa

“…The significantly positive correlation between bee species' abundance, richness and evenness in savannas and cotton fields but not in sesame fields indicates that both crop types differed regarding their attractiveness to bees or that the surrounding landscape affected bee communities of cotton and sesame fields not consistently (Williams & Winfree, 2013). In a study of landscape effects on bees in Mango ( Mangifera indica L.) orchards in central Thailand, the authors reported that characteristics of the overall bee community were associated more with farm scale factors than with landscape factors (Tangtorwongsakul, Warrit, & Gale, 2018). Hence, our results show that depending on crop type, bee communities of savanna habitats can impact bee community structure in agricultural fields and vice versa (Klein, Steffan‐Dewenter, & Tscharntke, 2003b; Ricketts, 2004).…”