scholarly journals Delivery of crop pollination services is an insufficient argument for wild pollinator conservation

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
David Kleijn ◽  
Rachael Winfree ◽  
Ignasi Bartomeus ◽  
Luísa G Carvalheiro ◽  
Mickaël Henry ◽  
...  

Abstract There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.

Author(s):  
Rachel A. Nalepa ◽  
Graham Epstein ◽  
Jeremy Pittman ◽  
Sheila R. Colla

Abstract Pollination services are critical for food production. Although domesticated honey bees are important pollinators in agriculture, there is growing interest in supporting naturally occurring wild bees. Diversifying pollination management strategies by encouraging healthy wild bee communities may be especially useful for growers of insect-pollinated crops, such as apples. Although research has identified several land management practices that can enhance local pollinator communities on farms, there are few studies on the factors that influence growers to adopt pollinator-supporting actions on their land. Here, we surveyed 75 Canadian apple growers and used regression models to explore the influence of farm characteristics and perceptions about bees on the likelihood of adopting 15 unique pollinator-supporting practices. We also provide a descriptive analysis of growers' pollination management practices and self-assessed resourcefulness on the ability to improve habitat for wild pollinators on the farm. We found that an increase in three variables: awareness of wild bees, perception of the severity of threats facing wild populations, and the perception of the benefits provided by wild bees is associated with more pollinator-supporting practices on the farm. Overall, growers were less likely to adopt pollinator-friendly practices as the fraction of rented land increased and as the perceived costs of implementing these practices rose. We found ‘low-hanging fruit’ (i.e., pollinator-supporting practices that could be easily and inexpensively implemented) were adopted by less than one-third of growers and that the majority of those surveyed had little to no knowledge on what actions to take if they wanted to improve their farms for wild bees or where to go for that knowledge. Our results suggest that policies and programs that focus on raising grower awareness of wild bees, increasing grower perception of their benefits, and reducing the perceived costs of implementing pollinator-supporting practices may positively affect their uptake. A deeper understanding of grower perceptions will provide essential insight into how growers may contribute to wild pollinator conservation while potentially increasing agricultural production and reducing vulnerability borne of heavy reliance on managed pollinators.


2018 ◽  
Author(s):  
Daniel Montoya ◽  
Bart Haegeman ◽  
Sabrina Gaba ◽  
Claire de Mazancourt ◽  
Vincent Bretagnolle ◽  
...  

AbstractChanges in land use generate trade-offs in the delivery of ecosystem services in agricultural landscapes. However, we know little about how the stability of ecosystem services responds to landscape composition, and what ecological mechanisms underlie these trade-offs. Here, we develop a model to investigate the dynamics of three ecosystem services in intensively-managed agroecosystems, i.e. pollination-independent crop yield, crop pollination, and biodiversity. Our model reveals trade-offs and synergies imposed by landscape composition that affect not only the magnitude but also the stability of ecosystem service delivery. Trade-offs involving crop pollination are strongly affected by the degree to which crops depend on pollination and by their relative requirement for pollinator densities. We show conditions for crop production to increase with biodiversity and decreasing crop area, reconciling farmers’ profitability and biodiversity conservation. Our results further suggest that, for pollination-dependent crops, management strategies that focus on maximising yield will often overlook its stability. Given that agriculture has become more pollination-dependent over time, it is essential to understand the mechanisms driving these trade-offs to ensure food security.


2008 ◽  
Vol 276 (1655) ◽  
pp. 229-237 ◽  
Author(s):  
Rachael Winfree ◽  
Claire Kremen

Biological diversity could enhance ecosystem service provision by increasing the mean level of services provided, and/or by providing more consistent (stable) services over space and time. Ecological theory predicts that when an ecosystem service is provided by many species, it will be stabilized against disturbance by a variety of ‘stabilizing mechanisms.’ However, few studies have investigated whether stabilizing mechanisms occur in real landscapes affected by human disturbance. We used two datasets on crop pollination by wild native bees to screen for and differentiate among three stabilizing mechanisms: density compensation (negative co-variance among species' abundances); response diversity (differential response to environmental variables among species); and cross-scale resilience (response to the same environmental variable at different scales by different species). In both datasets, we found response diversity and cross-scale resilience, but not density compensation. We conclude that stabilizing mechanisms may contribute to the stability of pollination services in our study areas, emphasizing the insurance value of seemingly ‘redundant’ species. Furthermore, the absence of density compensation that we found at the landscape scale contrasts with findings of previous small-scale experimental and modelling work, suggesting that we should not assume that density compensation will stabilize ecosystem services in real landscapes.


2019 ◽  
Vol 113 (2) ◽  
pp. 562-574 ◽  
Author(s):  
C M McGrady ◽  
R Troyer ◽  
S J Fleischer

Abstract Wild bees supply sufficient pollination in Cucurbita agroecosystems in certain settings; however, some growers continue to stock fields with managed pollinators due to uncertainties of temporal and spatial variation on pollination services supplied by wild bees. Here, we evaluate wild bee pollination activity in wholesale, commercial pumpkin fields over 3 yr. We identified 37 species of bees foraging in commercial pumpkin fields. Honey bees (Apis mellifera L. [Hymenoptera: Apidae]), squash bees (Eucera (Peponapis) Say, Dorchin [Hymenoptera: Apidae]), and bumble bees (Bombus spp., primarily B. impatiens Cresson [Hymenoptera: Apidae]) were the most active pollinator taxa, responsible for over 95% of all pollination visits. Preference for female flowers decreased as distance from field edge increased for several bee taxa. Visitation rates from one key pollinator was negatively affected by field size. Visitation rates for multiple taxa exhibited a curvilinear response as the growing season progressed and responded positively to increasing floral density. We synthesized existing literature to estimate minimum ‘pollination thresholds’ per taxa and determined that each of the most active pollinator taxa exceeded these thresholds independently. Under current conditions, renting honey bee hives may be superfluous in this system. These results can aid growers when executing pollination management strategies and further highlights the importance of monitoring and conserving wild pollinator populations.


2016 ◽  
Author(s):  
Ignasi Bartomeus ◽  
Daniel P. Cariveau ◽  
Tina Harrison ◽  
Rachael Winfree

AbstractThe response and effect trait framework, if supported empirically, would provide for powerful and general predictions about how biodiversity loss will lead to loss in ecosystem function. This framework proposes that species traits will explain how different species respond to disturbance (i.e. response traits) as well as their contribution to ecosystem function (i.e. effect traits). However, predictive response and effect traits remain elusive for most systems. Here, we present detailed data on crop pollination services provided by native, wild bees to explore the role of six commonly used species traits in determining how crop pollination is affected by increasing agricultural intensification. Analyses were conducted in parallel for three crop systems (watermelon, cranberry, and blueberry) located within the same geographical region (mid-Atlantic USA). Bee species traits did not strongly predict species’ response to agricultural intensification, and the few traits that were weakly predictive were not consistent across crops. Similarly, no trait predicted species’ overall functional contribution in any of the three crop systems, although body size was a good predictor of per capita efficiency in two systems. So far, most studies looking for response or effect traits in pollination systems have found weak and often contradicting links. Overall we were unable to make generalizable predictions regarding species responses to land-use change and its effect on the delivery of ecosystem services. Pollinator traits may be useful for understanding ecological processes in some systems, but thus far the promise of traits-based ecology has yet to be fulfilled for pollination ecology.


2020 ◽  
Vol 71 (12) ◽  
pp. 1557 ◽  
Author(s):  
Nasreen Jeelani ◽  
Wen Yang ◽  
Lu Xia ◽  
Hai Liang Zhu ◽  
Shuqing An

Wetlands provide a wide range of ecosystem services, and so their conservation and wise use are receiving increasingly greater attention globally. China has a wealth of wetland ecosystems that are well known as hot spots of biological diversity. China has experienced a serious loss of wetlands owing to rapid urbanisation, population growth and industrialisation. Some of the major threats and challenges to wetlands are related to habitat degradation, loss of biodiversity and weaknesses in their protection and management. In this paper we review the distribution of wetlands in China and discuss the key factors that degrade these wetlands. We further discuss management strategies and make recommendations to strengthen the network of wetlands in China.


2015 ◽  
Vol 282 (1809) ◽  
pp. 20150299 ◽  
Author(s):  
Mia G. Park ◽  
E. J. Blitzer ◽  
Jason Gibbs ◽  
John E. Losey ◽  
Bryan N. Danforth

Wild bee communities provide underappreciated but critical agricultural pollination services. Given predicted global shortages in pollination services, managing agroecosystems to support thriving wild bee communities is, therefore, central to ensuring sustainable food production. Benefits of natural (including semi-natural) habitat for wild bee abundance and diversity on farms are well documented. By contrast, few studies have examined toxicity of pesticides on wild bees, let alone effects of farm-level pesticide exposure on entire bee communities. Whether beneficial natural areas could mediate effects of harmful pesticides on wild bees is also unknown. Here, we assess the effect of conventional pesticide use on the wild bee community visiting apple ( Malus domestica ) within a gradient of percentage natural area in the landscape. Wild bee community abundance and species richness decreased linearly with increasing pesticide use in orchards one year after application; however, pesticide effects on wild bees were buffered by increasing proportion of natural habitat in the surrounding landscape. A significant contribution of fungicides to observed pesticide effects suggests deleterious properties of a class of pesticides that was, until recently, considered benign to bees. Our results demonstrate extended benefits of natural areas for wild pollinators and highlight the importance of considering the landscape context when weighing up the costs of pest management on crop pollination services.


2019 ◽  
Vol 7 ◽  
Author(s):  
Casey Delphia ◽  
Terry Griswold ◽  
Elizabeth Reese ◽  
Kevin O'Neill ◽  
Laura Burkle

Over three years (2013-2015), we sampled bees using nets and bowl traps on four diversified vegetable farms in Gallatin County, Montana, USA, as part of a study evaluating the use of wildflower strips for supporting wild bees and crop pollination services on farmlands (Delphia et al. In prep). We document 202 species and morphospecies from 32 genera within five families, of which 25 species represent the first published state records for Montana. This study increases our overall understanding of the distribution of wild bee species associated with agroecosystems of the northern US Rockies, which is important for efforts aimed at conserving bee biodiversity and supporting sustainable crop pollination systems on farmlands.We provide a species list of wild bees associated with diversified farmlands in Montana and increase the number of published bee species records in the state from 374 to at least 399. The list includes new distributional records for 25 wild bee species, including two species that represent considerable expansions of their known ranges, Lasioglossum (Dialictus) clematisellum (Cockerell 1904) with previously published records from New Mexico, Arizona, California and Utah and Melissodes (Eumelissodes) niveus Robertson 1895 which was reported to range from New York to Minnesota and Kansas, south to North Carolina, Alabama and Mississippi.


2006 ◽  
Vol 274 (1608) ◽  
pp. 303-313 ◽  
Author(s):  
Alexandra-Maria Klein ◽  
Bernard E Vaissière ◽  
James H Cane ◽  
Ingolf Steffan-Dewenter ◽  
Saul A Cunningham ◽  
...  

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.


2021 ◽  
Author(s):  
Pankaj Kumar ◽  
Sukhdeep Kaur Brar

Plants nutrients are necessary in increasing production and productivity of crops and healthy food for the world’s ever increasing population. Today, soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which cause a serious threat to human health and the environment. Bio-fertilizer has been identified as an alternative for increasing soil fertility and crop production in sustainable farming. The exploitation of beneficial microbes as bio-fertilizers has become of paramount importance in agricultural sector due to their potential role in food safety and sustainable crop production. Bio-fertilizer can be an important component of integrated nutrients management. Microorganisms that are commonly used as bio-fertilizer components include; nitrogen fixers (N-fixer), potassium and phosphorus solubilizers, growth promoting rhizobacteria (PGPRs), endo and ecto mycorrhizal fungi, cyanobacteria and other useful microscopic organisms. The use of bio-fertilizers leads to improved nutrients and water uptake, plant growth and plant tolerance to abiotic and biotic factors. In wheat, non-symbiotic spp. like Azotobacter and streptomyces may be used as a potential source of plant growth promoter and also can reduce chemical fertilizer up to 25% with compromising yield. Thus, these potential biological fertilizers would play a key role in productivity and sustainability of soil and also in protecting the environment as eco-friendly and cost effective inputs for the farmers. This review will overview the importance of biofertilizers with different sources of chemical fertilizers in wheat.


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