“Farming with Alternative Pollinators” approach increases pollinator abundance and diversity in faba bean fields

Abstract

Pollinators are threatened worldwide and strategies and measures to support their conservation are proliferating. Among them, the approach “Farming with Alternative Pollinators” (FAP) aims to support pollinators by seeding strips of pollinator-attracting cultivated plants surrounding the crops, and simultaneously providing income to the farmer. In this study we assessed whether this approach supports pollinator diversity in agro-ecosystems and increases flower visitor diversity and abundance in faba bean fields in north-west Morocco. We tested the impact of FAP using a variety of marketable habitat enhancement plants (MHEP): flax, coriander, arugula, chia and canola. A total of 62 pollinator species were recorded, among which almost half of them are new records for the region. Most wild pollinators recorded in faba bean were digger bees (genus Anthophora) and long-horn bees (genus Eucera). MHEP shared diverse flower visitors with faba bean and hosted diverse pollinator groups that did not meet their food requirements from the main crop. The FAP approach highly increased flower visitor abundance and diversity in the whole FAP fields, however it did not generate significant pollinator spillover towards the main crop. Implications for insect conservation: our results show that the FAP approach is an effective approach to mitigate pollinator decline in agro-ecosystems.

Impact of the “Farming With Alternative Pollinators” Approach on Crop Pollinator Pollen Diet

“…Our results show that the FAP approach displayed a neutral effect on crop flower visitor dietary breadth and the number of pollen genera carried or collected by crop flower visitors. These findings are in agreement with previous research that has found that wildflowers strips, hedgerows, and MHEP do not support crop flower visitor abundance, richness, and pollen diet (Sardiñas and Kremen, 2015;Sardiñas et al, 2016;Zamorano et al, 2020;Sentil et al, 2021). In contrast, flower strips are also known to benefit the pollen diet of common bees (e.g., honeybees and bumblebees), but not necessarily of wild solitary bees (Carvell et al, 2007;.…”

“…Farming with Alternative Pollinators fields provides, in addition to MHEP, nesting and water support made out of local materials. The approach demonstrated its effectiveness in increasing crop yield and reducing pest abundance (Christmann et al, 2017(Christmann et al, , 2021a, and significantly boosting pollinator abundance and diversity in agro-ecosystems (Christmann et al, 2021a,b;Sentil et al, 2021).…”

Diversity and Relative Abundance of Insect Pollinators in Moroccan Agroecosystems

“…In particular, Lhomme et al (2020) recorded a total of 961 wild bee species which ranks Morocco as the fifth most species rich country for bee richness in the Mediterranean Basin, confirming previous estimates that Morocco comprises a hotspot of wild bee diversity and pollinators in general (Patiny and Michez, 2007;Patiny et al, 2009). However, few publications exist that focus on insect pollinators and their importance in Moroccan agroecosystems (Christmann et al, 2017(Christmann et al, , 2021Sabbahi, 2021;Sentil et al, 2021).…”

“…We assume that MHEP did not affect the crop pollinator community in FAP fields based on previous research in the same sites. This study has demonstrated using visitation data and pollen load analysis that MHEPs affected neither the crop pollinator's abundance and richness nor the crop pollinator's pollen diet (Sentil et al, 2021(Sentil et al, , 2022.…”

“…Assessment of pesticide impact and risk to solitary ground-nesting bees as demonstrated by Christmann (2022), may be particularly important for the protection of pollinators in developing countries with high pesticide use (Dicks et al, 2021). For faba bean, cherry and apple that bloom in early season, seeding adequate complementary flowering crops (Christmann and Aw-Hassan, 2012;Sentil et al, 2021), wildflowers strips (Garibaldi et al, 2011;Sutter et al, 2017;Muñoz et al, 2021) or hedgerows (Morandin and Kremen, 2013) may help to attract early flying bees like the genera Eucera, Anthophora, and Bombus and help to conserve these bees in the agricultural landscape.…”