Importance of pollinators in changing landscapes for world crops. Proc R Soc Lon B Biol Sci

Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, California, United States
Proceedings of the Royal Society B: Biological Sciences (Impact Factor: 5.05). 03/2007; 274(1608):303-13. DOI: 10.1098/rspb.2006.3721
Source: PubMed


The extent of our reliance on animal pollination for world crop production for human food has not previously been evaluated and the previous estimates for countries or continents have seldom used primary data. In this review, we expand the previous estimates using novel primary data from 200 countries and found that fruit, vegetable or seed production from 87 of the leading global food crops is dependent upon animal pollination, while 28 crops do not rely upon animal pollination. However, global production volumes give a contrasting perspective, since 60% of global production comes from crops that do not depend on animal pollination, 35% from crops that depend on pollinators, and 5% are unevaluated. Using all crops traded on the world market and setting aside crops that are solely passively self-pollinated, wind-pollinated or parthenocarpic, we then evaluated the level of dependence on animal-mediated pollination for crops that are directly consumed by humans. We found that pollinators are essential for 13 crops, production is highly pollinator dependent for 30, moderately for 27, slightly for 21, unimportant for 7, and is of unknown significance for the remaining 9. We further evaluated whether local and landscape-wide management for natural pollination services could help to sustain crop diversity and production. Case studies for nine crops on four continents revealed that agricultural intensification jeopardizes wild bee communities and their stabilizing effect on pollination services at the landscape scale.

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    • "The importance of pollinators to global agricultural stability is well documented (Klein et al., 2007;Garibaldi et al., 2013). Worldwide an estimated 35% of crop production, including many of our most nutritious foods, benefit from insect pollination (Klein et al., 2007;Aizen et al., 2008). For many crops, the most widely used pollinator is the European honey bee (Apis mellifera L.). "
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    ABSTRACT: Understanding the importance of biodiversity in applied settings is a central theme for ecologists. Pollination is an essential ecosystem service, which may rely on biodiversity for effectiveness and stability. Empirical examples which link functional outcomes of increased biodiversity to pollination services are rare. To investigate the importance of wild and managed pollinator communities to apple production, we assessed the effect of wild and managed bee abundance and diversity on pollen limitation and seed set on commercial farms in New York State. Seed set increased and pollen limitation decreased with increasing wild bee species richness, functional group diversity (based on nesting, sociality, and size traits), and abundance, but not with honey bee abundance. Functional group diversity explained more variation in apple seed set than species richness. Our findings demonstrate the important role of functional complementarity of wild bees, defined here as functional group diversity, to crop pollination even in the presence of large populations of managed honey bees. Therefore, our results suggest that management of diverse pollinator communities may decrease reliance on managed honey bees for pollination services and enhance crop yields.
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    • "Recent reports on global pollinator declines (Biesmeijer et al., 2006; Potts et al., 2010a; Cameron et al., 2011) are alarming, especially with respect to the increasing demands for pollination services (Klein et al., 2007; Aizen and Harder, 2009). Honey bees are the most economically valuable pollinators (Klein et al., 2007). However, the number of managed honey bees decreased by one fourth in Europe between 1985 and 2005 (Potts et al., 2010b; Goulson et al., 2015) and by more than one half in North America between 1947 and 2005 (vanEngelsdorp et al., 2008; Goulson et al., 2015; National Research Council, 2007). "
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    ABSTRACT: A strong immune defense is vital for honey bee health and colony survival. This defense can be weakened by environmental factors that may render honey bees more vulnerable to parasites and pathogens. Honey bees are frequently exposed to neonicotinoid pesticides, which are being discussed as one of the stress factors that may lead to colony failure. We investigated the sublethal effects of the neonicotinoids thiacloprid, imidacloprid, and clothianidin on individual immunity, by studying three major aspects of immunocompetence in worker bees: total hemocyte number, encapsulation response, and antimicrobial activity of the hemolymph. In laboratory experiments, we found a strong impact of all three neonicotinoids. Thiacloprid (24 h oral exposure, 200 lg/l or 2000 lg/l) and imidacloprid (1 lg/l or 10 lg/l) reduced hemocyte density, encapsulation response, and antimicrobial activity even at field realistic concentrations. Clothianidin had an effect on these immune parameters only at higher than field realistic concentrations (50–200 lg/l). These results suggest that neonicotinoids affect the individual immunocompetence of honey bees, possibly leading to an impaired disease resistance capacity. � 2016 Elsevier Ltd. All rights reserved.
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    • "Especially large yield losses can occur when high temperatures cause damage during crop floral development and anthesis (Hedhly, 2011; Luo, 2011), as many crop products (e.g., fruits, grains) are the direct result of successful fertilization. Insect pollinated crops constitute approximately a third of global food production (Klein et al., 2007), but there is no comprehensive evidence of how their fertilization may be affected by heat stress. Studies in these crops have typically measured the effect of heat stress in absence of insect pollinators (Peet et al., 1998; Young et al., 2004), potentially missing important changes in the interactions between plants and their pollinators following stress. "
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