Effects of Forest Cover on Fruit Set in the Woodland Herb, Maianthemum canadense (Liliaceae)

Animal pollination has been recognized as an essential ecosystem function that is potentially under various environmental stresses. We investigated the landscape effects of forest cover at multiple spatial scales on the sexual reproductive success of a common woodland herb in North America, Maianthemum canadense. This species is a self-incompatible species and pollinated by insects requiring natural landscapes. Nine populations were selected in deciduous forests within agricultural fields of southern Ontario, Canada. We investigated whether fruiting success decreases as forest cover surrounding the plant populations increases at the landscape scale. Forest cover was quantified by the proportion of forest within six different radii from 250 to 1500 m. Analyses showed relationships with the proportion of forest at 750- and 1000-m radii and fruiting success in populations of M. canadense. These findings suggest potential local extirpation of M. canadense and indicate that forest loss can negatively impact on even some common woodland herbs

Reverse taxonomy for elucidating diversity of insect-associated nematodes: a case study with termites

BACKGROUND: The molecular operational taxonomic unit(MOTU)has recently been applied to microbial and microscopic animal biodiversity surveys. However, in many cases, some of the MOTUs cannot be definitively tied to any of the taxonomic groups in current databases. To surmount these limitations, the concept of "reverse taxonomy" has been proposed, i.e. to primarily list the MOTUs with morphological information, and then identify and/or describe them at genus/species level using subsamples or by re-isolating the target organisms. Nevertheless, the application of "reverse taxonomy" has not been sufficiently evaluated. Therefore, the practical applicability of "reverse taxonomy" is tested using termite-associated nematodes as a model system for phoretic/parasitic organisms which have high habitat specificity and a potential handle (their termite host species) for re-isolation attempts. METHODOLOGY: Forty-eight species (from 298 colonies) of termites collected from the American tropics and subtropics were examined for their nematode associates using the reverse taxonomy method and culturing attempts (morphological identification and further sequencing efforts). The survey yielded 51 sequence types (= MOTUs) belonging to 19 tentatively identified genera. Within these, four were identified based on molecular data with preliminary morphological observation, and an additional seven were identified or characterized from successful culturing, leaving eight genera unidentified. CONCLUSIONS: That 1/3 of the genera were not successfully identified suggests deficiencies in the depth of available sequences in the database and biological characters, i.e. usually isolated as phoretic/parasitic stages which are not available for morphological identification, and too many undiscovered lineages of nematodes. Although there still is the issue of culturability of nematodes, culturing attempts could help to make reverse taxonomy methods more effective. However, expansion of the database, i.e., production of more DNA barcodes tied to biological information by finding and characterizing additional new and known lineages, is necessary for analyzing functional diversity.Natsumi Kanzaki, Robin M. Giblin-Davis, Rudolf H. Scheffrahn, Hisatomo Taki, Alejandro Esquivel, Kerrie A. Davies and E. Allen Herr

Responses to risks and opportunities associated with pollinators and pollination

The overall aim of the thematic assessment of Pollinators, Pollination and Food Production is to assess animal pollination as a regulating ecosystem service under pinning food production in the context of its contribution to nature'sgifts to people and supporting a good quality of life. Toachieve this, the focus is on the role of native and exoticpollinators, the status of, and trends in pollinators andpollinator-plant networks and pollination, drivers of change,impacts on human well-being, food production in responseto pollination declines and deficits and the effectiveness ofresponses from various governance systems to pollinationdeclines and deficits. The scope is global, covering allcontinents except Antarctica, where no pollinators areknown. The assessment brings together contributions notonly from natural, social and economic science perspectives but also from knowledge of indigenous and local community stake holders and practitioners.The assessment strives to critically review the broadest range of evidence and make its findings readily availableto support policy and management responses to declinesand deficits in pollination. The report represents the firstIPBES thematic assessment deliverable that aims toidentify policy-relevant findings for decision-making ingovernment, the private sector and civil society, as wellas helping to demonstrate how an essential ecosystem service could potentially contribute to the post-2015 development agendaFil: Dicks, Lynn. University of Cambridge; Reino UnidoFil: Viana, Blandina Felipe. Universidad federal de Bahia; BrasilFil: del Coro Arizmendi, Maria. Universidad Nacional Autónoma de México; MéxicoFil: Bommarco, Riccardo. Mid Sweden University.; SueciaFil: Brosi, Berry. University of Washington; Estados UnidosFil: Cunningham, Saul. Australian National University; AustraliaFil: Galetto, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lopes, Ariadna. Universidade Federal de Pernambuco; BrasilFil: Taki, Hisatomo. University of Florida; Estados Unido

Non-bee insects are important contributors to global crop pollination

Wild and managed bees are well documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25–50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines

Forest biodiversity, ecosystem functioning and the provision of ecosystem services

Forests are critical habitats for biodiversity and they are also essential for the provision of a wide range of ecosystem services that are important to human well-being. There is increasing evidence that biodiversity contributes to forest ecosystem functioning and the provision of ecosystem services. Here we provide a review of forest ecosystem services including biomass production, habitat provisioning services, pollination, seed dispersal, resistance to wind storms, fire regulation and mitigation, pest regulation of native and invading insects, carbon sequestration, and cultural ecosystem services, in relation to forest type, structure and diversity. We also consider relationships between forest biodiversity and multifunctionality, and trade-offs among ecosystem services. We compare the concepts of ecosystem processes, functions and services to clarify their definitions. Our review of published studies indicates a lack of empirical studies that establish quantitative and causal relationships between forest biodiversity and many important ecosystem services. The literature is highly skewed; studies on provisioning of nutrition and energy, and on cultural services, delivered by mixed-species forests are under-represented. Planted forests offer ample opportunity for optimising their composition and diversity because replanting after harvesting is a recurring process. Planting mixed-species forests should be given more consideration as they are likely to provide a wider range of ecosystem services within the forest and for adjacent land uses. This review also serves as the introduction to this special issue of Biodiversity and Conservation on various aspects of forest biodiversity and ecosystem services

Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

Scale-dependent effects of habitat area on species interaction networks: invasive species alter relationships

<p>Abstract</p> <p>Background</p> <p>The positive relationship between habitat area and species number is considered a fundamental rule in ecology. This relationship predicts that the link number of species interactions increases with habitat area, and structure is related to habitat area. Biological invasions can affect species interactions and area relationships. However, how these relationships change at different spatial scales has remained unexplored. We analysed understory plant–pollinator networks in seven temperate forest sites at 20 spatial scales (radius 120–2020 m) to clarify scale-associated relationships between forest area and plant–pollinator networks.</p> <p>Results</p> <p>The pooled data described interactions between 18 plant (including an exotic) and 89 pollinator (including an exotic) species. The total number of species and the number of interaction links between plant and pollinator species were negatively correlated with forest area, with the highest correlation coefficient at radii of 1520 and 1620 m, respectively. These results are not concordant with the pattern predicted by species–area relationships. However, when associations with exotic species were excluded, the total number of species and the number of interaction links were positively correlated with forest area (the highest correlation coefficient at a radius of 820 m). The network structure, i.e., connectance and nestedness, was also related to forest area (the highest correlation coefficients at radii of 720–820 m), when associations with exotics were excluded. In the study area, the exotic plant species <it>Alliaria petiolata</it>, which has invaded relatively small forest patches surrounded by agricultural fields, may have supported more native pollinator species than initially expected. Therefore, this invasive plant may have altered the original relationships between forest area and plant–pollinator networks.</p> <p>Conclusions</p> <p>Our results demonstrate scale-dependent effects of forest area on the size and structure of plant–pollinator networks. We also suggest that a single exotic plant species can impact plant–pollinator networks, even in temperate continental habitats.</p

Comparison of the Ecological Traits and Boring Densities of <i>Aromia bungii</i> (Faldermann, 1835) (Coleoptera: Cerambycidae) in Two Host Tree Species

We investigated the ecological traits of emerging adults and the boring density in Aromia bungii-infested flowering cherry (Cerasus × yedoensis ‘Somei-yoshino’) and peach (Prunus persica) trees to evaluate their suitability as food resources for A. bungii, and their vulnerability to infestation. The number of adults per m3 that emerged from P. persica was 10-times larger than from C. × yedoensis, and the numbers of emergence holes, entrance holes, and pupal chambers were also larger in P. persica logs. The lifetime fecundity of adults that emerged from P. persica was also higher. Elytral length, sex ratios, and adult lifespans did not differ between the two host trees. Our results indicate that peach trees provide more suitable conditions than do flowering cherry trees for A. bungii larvae. Although flowering cherry trees, primarily C. × yedoensis, which are currently grown as street or ornamental trees in Japan, have been more severely affected by A. bungii to date, the greater risk in the long term is to P. persica, an agricultural species in the main producing areas surrounding the Kanto region