240 research outputs found
Creating patches of native flowers facilitates crop pollination in large agricultural fields : mango as a case study
1. As cropland increases, fields become progressively isolated from pollinators, leading to
declines in pollinator-dependent crop productivity. With the rise in demand for pollinatordependent
foods, such productivity losses may accelerate conversion of natural areas to cropland.
Pollination–compensation measures involving managed pollinators or hand pollination
are not always optimal or are too costly. Introducing areas of native vegetation within cropland
has been proposed as a way to supplement crop pollinators, but this measure is
perceived by farmers to carry costs outweighing benefits to agricultural production. Studies
quantifying benefits of small patches of native flowers to crop pollination are therefore necessary
to encourage such practices.
2. To ascertain whether provision of floral resources within farmlands can facilitate pollination,
and hence, crop yields, small experimental patches of perennial native plants (native
flower compensation areas, NFCAs) were created in nonproductive areas of large commercial
fields of several cultivars of mango Mangifera indica.
3. Pesticide use and isolation from natural habitat were associated with declines in flying visitors
and in mango production (kg of marketable fresh fruit), but presence of NFCAs ameliorated
these declines, and NFCAs did not harbour any mango pests. In areas far from natural
vegetation, orchards near NFCAs had significantly higher diversity and abundance of mango
flying visitors, as well as mango production, than orchards far from NFCAs, although these
measures were still lower than in orchards close to natural areas.
4. Neither the most abundant flower visitors to mango (ants) nor initial fruit set was significantly
affected by distance, pesticides or NFCAs, suggesting that although fertilization is
associated with factors unaffected by isolation from natural habitat and pesticide use (i.e. selfand
ant-pollination), viable fruit set (and ultimately, production) requires cross-pollination,
for which flying visitors are essential.
5. Synthesis and applications. Our results show that the presence of small patches of native
flowers within large farms can increase pollinator-dependent crop production if combined with
preservation of remaining fragments of natural habitat and judicious use of pesticides. Native
flower compensation areas represent a profitable management measure for farmers, increasing
cost-effectiveness of cropland while indirectly contributing to preservation of natural habitat.South African National Biodiversity Institute,The University of Pretoria and STEP (Status and Trends of European Pollinators, grant no244090).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2664hb2013ab201
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The impact of over 80 years of land cover changes on bee and wasp pollinator communities in England
Change in land cover is thought to be one of the key drivers of pollinator declines, and yet there is a dearth of studies exploring the relationships between historical changes in land cover and shifts in pollinator communities. Here, we explore, for the first time, land cover changes in England over more than 80 years, and relate them to concurrent shifts in bee and wasp species richness and community composition. Using historical data from 14 sites across four counties, we quantify the key land cover changes within and around these sites and estimate the changes in richness and composition of pollinators. Land cover changes within sites, as well as changes within a 1 km radius outside the sites, have significant effects on richness and composition of bee and wasp species, with changes in edge habitats between major land classes also having a key influence. Our results highlight not just the land cover changes that may be detrimental to pollinator communities, but also provide an insight into how increases in habitat diversity may benefit species diversity, and could thus help inform policy and practice for future land management
Multi-trait meta-analysis identified genomic regions associated with sexual precocity in tropical beef cattle
Multi-trait meta-analyses are a strategy to produce more accurate genome-wide association studies (GWAS), especially for complex phenotypes. We carried out a meta-analysis study for traits related to sexual precocity in tropical beef cattle (Nellore and Brahman) aiming to identify important genomic regions affecting these traits. The traits included in the analyses were age at first calving (AFC), early pregnancy (EP), age at first corpus luteum (AGECL), first postpartum anoestrus interval (PPAI) and scrotal circumference (SC). The traits AFC, EP and SCN were measured in Nellore cattle, while AGECL, PPAI and SCB were measured in Brahman cattle. Meta-analysis resulted in 108 significant single nucleotide polymorphisms (SNP), at an empirical threshold P-value of 1.39x10-5 (FDR < 0.05). Within 0.5 Mb of the significant SNP, candidate genes were annotated and analyzed for functional enrichment. Most of the closest genes to the SNP with higher significance in each chromosome have been associated with important roles in reproductive function, these are TSC22D2, KLF7, ARHGAP29, 7SK, MAP3K5, TLE3, WDR5, TAF3, TMEM68, PPP1R15B, NR2F2, GALR1, SUFU and KCNU1. We did not observe any significant SNP in BTA5, BTA12, BTA17, BTA18, BTA19, BTA20, BTA22, BTA23, BTA25 and BTA28. Although the majority of significant SNP are in BTA14, it was identified significant associations in multiple chromosomes (19 out of 29 autosomes), which is consistent with the postulation that reproductive traits are complex polygenic phenotypes. Five proposed association regions harbor the majority of the significant SNP (76 %) and were distributed over four chromosomes (P < 1.39x10-5, FDR < 0.05): BTA2 (5.55%) from 95 to 96 Mb, BTA4 (5.55%) from 94.1 to 94.8 Mb, BTA14 (59.26%) from 24 to 25 Mb and 29 to 30 Mb, and BTA21 (5.55%) from 6.7 Mb to 11.4 Mb. These regions harbored key genes related to reproductive function. Moreover, these genes were enriched for functional groups associated with immune response, maternal-fetal tolerance, pregnancy maintenance, embryo development, fertility and response to stress. Further studies including other breeds and precocity traits could confirm the importance of these regions and identify new candidate regions for sexual precocity in beef cattle
Population genomics of Bombus terrestris reveals high but unstructured genetic diversity in a potential glacial refugium
Ongoing climate change is expected to cause an increase in temperature and a reduction of precipitation levels in the Mediterranean region, which might cause changes in many species distributions. These effects negatively influence species gene pools, decreasing genetic variability and adaptive potential. Here, we use mitochondrial DNA and RADseq to analyse population genetic structure and genetic diversity of the bumblebee species Bombus terrestris (subspecies Bombus terrestris lusitanicus), in the Iberian Peninsula. Although this subspecies shows a panmictic pattern of population structure across Iberia and beyond, we found differentiation between subspecies B. t. lusitanicus and B. t. africanus, probably caused by the existence of barriers to gene flow between Iberia and North Africa. Furthermore, the results revealed that the Iberian Peninsula harbours a large fraction of B. terrestris intraspecific genetic variation, with the highest number of mitochondrial haplotypes found when compared with any other region in Europe studied so far, suggesting a potential role for the Iberian Peninsula as a glacial refugium. Our findings strengthen the idea that Iberia is a very important source of diversity for the global genetic pool of this species, because rare alleles might play a role in population resilience against human- or climate-mediated changes.info:eu-repo/semantics/publishedVersio
Managed native bees (Scaptotrigona aff. postica) and wild pollinators impact on açaípalm (Euterpe oleraceaMart.) yield in eastern Brazilian Amazon. .
Agricultural expansion is a major driver of habitat loss, which triggers biodiversitydecline, including wild pollinators, and affects crop production. 76% of world crops are dependenton biotic pollination, therefore Integrated Crop Pollination (ICP), the arrangement of managed andwild bees combined with farm practices that support wild pollinators (e.g. habitat management),could help reverse negative impacts of pollinators deficit in tropical crops, while maximisingbenefits to producers. In the Amazon River delta, the Açaí palm (Euterpe oleracea Mart.Arecaceae) is unmatched among native forest plants in its cultural, social and economic importanceto the region. Its thick juice (?vinho do açaí?) is an important staple food in both rural and urbanpopulations. We applied the ICP approach to açaí palm production in the eastern Brazilian Amazonand evaluated the effects of a native managed stingless bee, Scaptotrigona postica, and landscape-level forest conservation on yield and socioeconomic outcomes, on 18 açaí palm plantations innortheast Pará state, Brazil. We found that managed stingless bees and forest cover enhancedflower visitor abundance on açaí palm inflorescences, but visitor abundance increases attributed tomanaged bees were associated with shifts in flower visitor evenness and diversity, due to reducedvisitation of wild bees close to managed colonies. Fruit production on inflorescences waspositively related to bee abundance and bee diversity. Consequently, overall pollination efficiencywas lower in plantations dominated by managed bees, especially when native forest cover in thesurroundings was low. At the hectare scale, managed bees and landscape-level forest conservationhad complementary effects on fruit yields, but additional costs of bee colonies mean profits werelargely explained by surrounding forest cover. We concluded that managed bees have greatpotential to boost açaí fruit yields, but the increased environmental and socioeconomic risksassociated with this activity indicates that growers should prioritise forest conservation and habitatrestoration to safeguard natural pollination ecosystem service and improve the overall sustainability of açaí fruit production in the eastern Brazilian Amazon
Soil-derived Nature’s Contributions to People and their contribution to the UN Sustainable Development Goals
Acknowledgments The input of PS contributes to Soils-R-GRREAT (NE/P019455/1) and the input of PS and SK contributes to the European Union's Horizon 2020 Research and Innovation Programme through project CIRCASA (grant agreement no. 774378). PR acknowledges funding from UK Greenhouse Gas Removal Programme (NE/P01982X/2). GB De Deyn acknowledges FoodShot Global for its support. TKA acknowledges the support of “Towards Integrated Nitrogen Management System (INMS) funded by the Global Environment Facility (GEF), executed through the UK’s Natural Environment Research Council (NERC). The input of DG was supported by the New Zealand Ministry of Business, Innovation and Employment (MBIE) strategic science investment fund (SSIF). PMS acknowledges support from the Australian Research Council (Project FT140100610). PM’s work on ecosystem services is supported by a National Science Foundation grant #1853759, “Understanding the Use of Ecosystem Services Concepts in Environmental Policy”. LGC is funded by National Council for Scientific and Technological Development (CNPq, Brazil – grants 421668/2018-0 and 305157/2018-3) and by Lisboa2020 FCT/EU (project 028360). BS acknowledges support from the Lancaster Environment Centre Project.Peer reviewedPostprin
Development of genomic predictions for Angus cattle in Brazil incorporating genotypes from related american sires.
Genomic prediction has become the new standard for genetic improvement programs, and currently, there is a desire to implement this technology for the evaluation of Angus cattle in Brazil. Thus, the main objective of this study was to assess the feasibility of evaluating young Brazilian Angus (BA) bulls and heifers for 12 routinely recorded traits using single-step genomic BLUP (ssGBLUP) with and without genotypes from American Angus (AA) sires. The second objective was to obtain estimates of effective population size (Ne) and linkage disequilibrium (LD) in the Brazilian Angus population. The dataset contained phenotypic information for up to 277,661 animals belonging to the Promebo breeding program, pedigree for 362,900, of which 1,386 were genotyped for 50k, 77k, and 150k single nucleotide polymorphism (SNP) panels. After imputation and quality control, 61,666 SNPs were available for the analyses. In addition, genotypes from 332 American Angus (AA) sires widely used in Brazil were retrieved from the AA Association database to be used for genomic predictions. Bivariate animal models were used to estimate variance components, traditional EBV, and genomic EBV (GEBV). Validation was carried out with the linear regression method (LR) using young-genotyped animals born between 2013 and 2015 without phenotypes in the reduced dataset and with records in the complete dataset. Validation animals were further split into progeny of BA and AA sires to evaluate if their progenies would benefit by including genotypes from AA sires. The Ne was 254 based on pedigree and 197 based on LD, and the average LD (±SD) and distance between adjacent single nucleotide polymorphisms (SNPs) across all chromosomes were 0.27 (±0.27) and 40743.68 bp, respectively. Prediction accuracies with ssGBLUP outperformed BLUP for all traits, improving accuracies by, on average, 16% for BA young bulls and heifers. The GEBV prediction accuracies ranged from 0.37 (total maternal for weaning weight and tick count) to 0.54 (yearling precocity) across all traits, and dispersion (LR coefficients) fluctuated between 0.92 and 1.06. Inclusion of genotyped sires from the AA improved GEBV accuracies by 2%, on average, compared to using only the BA reference population. Our study indicated that genomic information could help us to improve GEBV accuracies and hence genetic progress in the Brazilian Angus population. The inclusion of genotypes from American Angus sires heavily used in Brazil just marginally increased the GEBV accuracies for selection candidates.skac009
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Costing conservation: an expert appraisal of the pollinator habitat benefits of England’s entry level stewardship
Pollination services provided by insects play a key role in English crop production and wider ecology. Despite growing evidence of the negative effects of habitat loss on pollinator populations, limited policy support is available to reverse this pressure. One measure that may provide beneficial habitat to pollinators is England’s entry level stewardship agri-environment scheme. This study uses a novel expert survey to develop weights for a range of models which adjust the balance of Entry Level Stewardship options within the current area of spending. The annual costs of establishing and maintaining these option compositions were estimated at £59.3–£12.4 M above current expenditure. Although this produced substantial reduction in private cost:benefit ratios, the benefits of the scheme to pollinator habitat rose by 7–140 %; significantly increasing the public cost:benefit ratio. This study demonstrates that the scheme has significant untapped potential to provide good quality habitat for pollinators across England, even within existing expenditure. The findings should open debate on the costs and benefits of specific entry level stewardship management options and how these can be enhanced to benefit both participants and biodiversity more equitably
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