Abstract

Summary 1 Multiple-species floral displays have been hypothesized to facilitate pollination by attracting a greater number and/or diversity of pollinators. Here I present experimental confirmation of pollination facilitation among coflowering plants that have morphologically distinct flowers. 2 Pollinator visits to Raphanus raphanistrum, a self-incompatible herbaceous plant, increased when it occurred with one or a combination of Cirsium arvense, Hypericum perforatum and Solidago canadensis than when it occurred alone. 3 Enhanced visitation to R. raphanistrum in mixed species plots was reflected by ...

Abstract

Pollen and silk attributes as well as floral synchrony are the most important morphological features that influence pollination and gene flow in the genus Zea., To characterize floral morphology and synchrony, 115 teosinte populations, 60 maize accessions representing 53 landraces, three improved open pollinated varieties and 14 commercial hybrids were evaluated. A high level of variation among the Zea populations was found. The pollen size in landraces and commercial hybrids was larger (103-105 mu m) than in teosinte (84 mu m). ...

Abstract

Pollen is an important vector of gene now in maize (Zea mays L.). Experiments were conducted to investigate the duration of pollen viability and the effectiveness of isolation distance for controlling gene flow. Pollen longevity was tested by collecting pollen at dehiseence and exposing it in a thin layer in the open air and sunshine for prescribed time periods before assessing pollen viability by measuring seed set after pollination and scoring visual appearance. Isolation distance efficacy was evaluated by growing 12.8-m(2) ...

Abstract

After dormancy, both pollen- and seed-cone buds resume development early in April at higher elevations on Vancouver Island. Pollen, formed the revious fall, is shed at the one-celled stage during the last half of April. Pollination occurs &ring a 2-week period. Pollen frequently germinates and elongates in the pollination drop within the micropyle before reaching the nucellus. Pollen tubes penetrate most of the nucellus during May and early June, then pollen-tube growth slows or stops until midJuly when the pollen tubes quickly ...

Abstract

Maize (Zea mays L.) Plus-Hybrids are a blend of cytoplasmic male-sterile (CMS) hybrids and unrelated male-fertile hybrids ensuring pollination of the whole stand. Combining potential benefits of male sterility (CMS effect) and allo-pollination (xenia effect), they often outperform the corresponding male-fertile sib-pollinated hybrids in terms of yield. The combining abilities of five CMS hybrids and eight pollinators were investigated in a factorial split-plot design in 12 environments in four countries and two years. The plant material from different breeders represented the ...

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587BO Times Cited:0 Cited References Count:62 =10.2135/cropsci2009.03.0117 ckluss

Abstract

Maize (Zea mays L.) Plus-Hybrids are a blend of cytoplasmic male-sterile (CMS) hybrids and unrelated male-fertile hybrids ensuring pollination of the whole stand. Combining potential benefits of male sterility (CMS effect) and allo-pollination (xenia effect), they often outperform the corresponding male-fertile sib-pollinated hybrids in terms of yield. The combining abilities of five CMS hybrids and eight pollinators were investigated in a factorial split-plot design in 12 environments in four countries and two years. The plant material from different breeders represented the ...

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587BO Times Cited:0 Cited References Count:62 =10.2135/cropsci2009.03.0117 ckluss

Abstract

Patterns of connectance and strength of mutual dependence in mutualisms have been examined by comparing the fraction of possible pairwise interactions established in a series of plant-pollinator and plant-seed disperser systems. As the number of species in the mutualistic system increases, the absolute number of interactions established increases, but connectance decreases exponentially. A given increase in diversity adds twice the number of interactions to dispersal systems as to pollination systems, suggesting a higher global specificity of the latter. Connectance patterns in ...

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{ArticleType:} research-article / Full publication date: May, 1987 / Copyright © 1987 The University of Chicago Press

Abstract

Animals pollinate 87% of the world's flowering plant species. Therefore, how pollinators respond to human-induced land-use change has important implications for plants and the species that depend on them. Here, we synthesize the published literature on how land-use change affects the main groups of pollinators: bees, butterflies, flies, birds, and bats. Responses to land-use change are predominantly negative but are highly variable within and across taxa. The directionality of pollinator response varies according to study design, with comparisons across gradients in ...

Abstract

Agricultural land use results in direct biodiversity decline through loss of natural habitat, but may also cause indirect cross-habitat effects on conservation areas. We conducted three landscape-scale field studies on 67 sites to test the hypothesis that mass flowering of oilseed rape (Brassica napus) results in a transient dilution of bees in crop fields, and in increased competition between crop plants and grassland plants for pollinators. Abundances of bumble-bees, which are the main pollinators of the grassland plant Primula veris, but ...

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Biofuel crops compete with wildflowers for bees Pollination of intensively farmed, flowering crops could affect the pollination of wild plants in neighbouring fields, according to a study by German researchers. In their one-year study, they found fewer bees visited wild plants that are close to oilseed rape fields, although the longer-term picture is less clear. The researchers warn that increasing cultivation of biofuel crops could possibly reduce wild flower populations. Bees pollinate both wild flowers and crop plants, providing invaluable ecosystem services to

Abstract

Flower visiting insects provide a vitally important pollination service for many crops and wild plants. Recent decline of pollinating insects due to anthropogenic modification of habitats and climate, in particular from 1950's onwards, is a major and widespread concern. However, few studies document the extent of declines in species diversity, and no studies have previously quantified local abundance declines. We here make a quantitative assessment of recent historical changes in bumblebee assemblages by comparing contemporary and historical survey data. Methodology/Principal Findings ...

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[EUn documented long-term (1930s to today) decline in Bombus spp. in Denmark (island of Funen) - loss of 5 species out of 12, significant decline in abundance and community composition]

Abstract

Understanding the negative and positive effects of agricultural land use for the conservation of biodiversity, and its relation to ecosystem services, needs a landscape perspective. Agriculture can contribute to the conservation of high-diversity systems, which may provide important ecosystem services such as pollination and biological control via complementarity and sampling effects. Land-use management is often focused on few species and local processes, but in dynamic, agricultural landscapes, only a diversity of insurance species may guarantee resilience (the capacity to reorganize ...

Abstract

* 1 Pollination is a key ecosystem service. Although bees are the most important pollinators, they are endangered by intensive agricultural practices. The present study investigated the effects of farmland management and environmental factors at local and landscape scales on bees in Central Hungary. * 2 Bees were sampled in winter cereal fields that varied in the amount of applied fertilizer and insecticide use. Measurements included total, small and large bee species richness and abundance; stability of total species ...

Abstract

Blue flag (Iris versicolor) is an insect-pollinated clonal plant found in wet habitats throughout northeastern North America. Our study of an isolated population on Kent Island, New Brunswick, showed that blue flag was self-compatible. Moreover, we found no evidence of inbreeding depression. Although individual flowers were protandrous, the timing of male and female phases and the precise behavior of flowers depended upon whether the flowers had been pollinated. Naturally pollinated or hand-pollinated flowers closed their stigmas shortly after pollination, making them ...

Abstract

In clonal species, sexual and asexual systems interact to create a hierarchy of reproduction. For example, self-pollination can occur within pollination units, flowers, ramets, or clones. We investigated the reproductive biology of a natural population of Iris versicolor using pollination manipulations and observations of pollinator behaviour. We found that (i) individuals were completely self-compatible, (ii) selfing rates were close to 100%, (iii) autonomous self-pollination can occur through stigma–anther contact or wind action, (iv) most seed and fruit set can be accounted ...

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Discusses pollination techniques, reproduction, floral morphology, and fruiting behavior.

Abstract

We determined that Eupatorium petiolare was either wind pollinated or self-fertilized, that Tagetes lunulata and Verbesina virgata showed autonomous self-fertilization, that Dahlia coccinea seems to be self-incompatible and pollinated by diurnal insects, and that, although overall longevity of capitula of virgata was greater in shaded sites, production of fruit per capitulum was greater in sunny sites. Overall longevity of capitula and longevity of capitula in the mature-flower stage showed great variability among species; overall longevity of capitula was longer for those ...

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ISI Document Delivery No.: 779IX Times Cited: 0 Cited Reference Count: 65 Figueroa-Castro, Dulce M. Cano-Santana, Zenon Consejo Nacional de Ciencia y Tecnologia[0202P-N9506]; Universidad Nacional Autonoma de Mexico We thank E. Camacho, C. Gonzalez, C. Anaya, R. Leon, O. Nunez, and C. Maravilla for assistance in the field. L. Dudley, S. Ellberg, R. Kaczorowski, J. Ketner, A. Dona, M. Brock, and two anonymous reviewers made valuable suggestions that helped to improve the manuscript. M. A. Romero-Romero and S. Mendoza provided technical assistance. This research was supported

Abstract

The ecological impacts of agriculture are of concern, especially with genetically modified and other intensive, modern cropping systems, yet little is known about effects on wild bee populations and subsequent implications for pollination. Pollination deficit (the difference between potential and actual pollination) and bee abundance were measured in organic, conventional, and herbicide-resistant, genetically modified (GM) canola fields (Brassica napus and B. rapa) in northern Alberta, Canada, in the summer of 2002. Bee abundance data were collected using pan traps and standardized ...

Abstract

Can economic forces be harnessed for biodiversity conservation? The answer hinges on characterizing the value of nature, a tricky business from biophysical, socioeconomic, and ethical perspectives. Although the societal benefits of native ecosystems are clearly immense, they remain largely unquantified for all but a few services. Here, we estimate the value of tropical forest in supplying pollination services to agriculture. We focus on coffee because it is one of the world's most valuable export commodities and is grown in many of ...

Abstract

The visual splendor of many diurnal flowers serves to attract visually guided pollinators such as bees and birds, but it remains to be seen whether bat-pollinated flowers have evolved analogous echo-acoustic signals to lure their echolocating pollinators. Here, we demonstrate how an unusual dish-shaped leaf displayed above the inflorescences of the vine Marcgravia evenia attracts bat pollinators. Specifically, this leaf’s echoes fulfilled requirements for an effective beacon, that is, they were strong, multidirectional, and had a recognizable invariant echo signature. In ...

Abstract

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 ...

Abstract

Directional evolutionary trends have long garnered interest because they suggest that evolution can be predictable. However, the identification of the trends themselves and the underlying processes that may produce them have often been controversial1. In 1862, in explaining the exceptionally long nectar spur of Angraecum sesquipedale, Darwin proposed that a coevolutionary ‘race’ had driven the directional increase in length of a plant’s spur and its pollinator’s tongue2. Thus he predicted the existence of an exceptionally long-tongued moth. Though the discovery of ...

Abstract

Animal pollination is one of the essential services provided by ecosystems to humans. In the face of a potential worldwide pollination crisis it is important to assess which countries may be more vulnerable in order to prioritize pollinator conservation efforts. The poverty level, the population density and the level of pollinator dependence for food provisioning are key aspects to identify vulnerable countries. We evaluate these aspects and determine the level of human food provisioning dependence on pollinators in Mexico, a developing ...

Abstract

Background and Aims Productivity of many crops benefits from the presence of pollinating insects, so a decline in pollinator abundance should compromise global agricultural production. Motivated by the lack of accurate estimates of the size of this threat, we quantified the effect of total loss of pollinators on global agricultural production and crop production diversity. The change in pollinator dependency over 46 years was also evaluated, considering the developed and developing world separately.Methods Using the extensive FAO dataset, yearly data were ...

Abstract

Summary 1.European agri-environment schemes (AESs) have so far delivered only moderate biodiversity gains. However, recent work has demonstrated that under a range of circumstances AESs can return substantial benefit both to biodiversity and ecosystem service delivery. This Special Profile brings together 13 papers that point the way to greater effectiveness. 2.One study in this Special Profile suggests that AES options modified by experience of working on the ground (i.e. guided by adaptive management) and applied to small fragmented pieces of land ...

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Introduction to Special Profile edition on agri-environment schemes, which includes De Deyn et al (2011) {2767}, Fritch et al (2011) {2764}, Fuentes-Montemayor et al (2011) {2765}, Gibbons et al (2011) {2884}, Jonason et al (2011) {2630}, Lin et al (2011) {2769}, Perkins et al (2011) {2406}, Power & Stout (2011) {2766}, Seppelt et al (2011) {2724}, Whittingham (2011) {2761}, Winqvist et al (2011)

Abstract

The species richness of flower-visiting insects has declined in past decades, raising concerns that the ecosystem service they provide by pollinating crops and wild plants is threatened. The relative commonness of different species with shared ecological traits can play a pervasive role in determining ecosystem functioning, but information on changes in abundances of pollinators over time is lacking. We gathered data on relative abundances of bumble-bee species in Swedish red clover fields during three periods in the last 70 years (1940s, ...

Abstract

Summary * 1 Over the last decades, biodiversity in agricultural landscapes has declined drastically. Initiatives to enhance biodiversity, such as agri-environment schemes, often have little effect, especially in intensively farmed landscapes. The effectiveness of conservation management may be improved by scheme implementation near high-quality habitats that can act as a source of species. We evaluated up to what distance high-quality habitats (nature reserves and artificially created flower-rich patches) affect the diversity of forbs and pollinators in intensively farmed landscapes of ...

Abstract

Summary * 1 Agri-environment schemes promote organic farming in an attempt to reduce the negative effects of agricultural intensification on farmland biodiversity and ecosystem services such as pollination. Farming system, landscape context and regional differences may all influence biodiversity, but their relative impact and possible interactions have been little explored. * 2 The study was performed in three regions (150 km apart, 400-500 km2 per region) differing in land use intensity. Within each region, seven pairs of conventionally and ...

Abstract

Summary 1. Agri-environment schemes attempt to counteract the loss of biodiversity and associated ecosystem services such as pollination and natural pest control in agro-ecosystems. However, only a few studies have evaluated whether these attempts are successful. 2. We studied the effects of managing meadows according to the prescriptions of ecological compensation areas (ECA), the most widely adopted agri-environment scheme in Switzerland, on both pollinator species richness and abundance, and the reproductive success of plants in nearby intensively managed meadows (IM). 3. ...

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Abstract

Abstract The loss and fragmentation of natural habitats by human activities are pervasive phenomena in terrestrial ecosystems across the Earth and the main driving forces behind current biodiversity loss. Animal-mediated pollination is a key process for the sexual reproduction of most extant flowering plants, and the one most consistently studied in the context of habitat fragmentation. By means of a meta-analysis we quantitatively reviewed the results from independent fragmentation studies throughout the last two decades, with the aim of testing whether ...

Abstract

Many ecosystem services are delivered by organisms that depend on habitats that are segregated spatially or temporally from the location where services are provided. Management of mobile organisms contributing to ecosystem services requires consideration not only of the local scale where services are delivered, but also the distribution of resources at the landscape scale, and the foraging ranges and dispersal movements of the mobile agents. We develop a conceptual model for exploring how one such mobile-agent-based ecosystem service (MABES), pollination, is ...

Abstract

In México and other countries, cultivation of pitahaya (Hylocereus spp.) is considered very promising because its fruit is well accepted and it is resistant to drought. However, new plantations in México have several problems, including genetic heterogeneity of plantation material and low fruit production relative to total flower production of some genotypes. Knowing biodiversity of a plant resource allows election of strategies for better use. This motivated the study of five genotypes (1, 3, 4, 5 and 6) cultivated in southern ...

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Source: Scopus

Abstract

Many hemiparasites, including several members of the Castilleja genus (Scrophulariaceae), obtain secondary compounds from their host plants. Both Castilleja miniata in subalpine Colorado and C. indivisa in central Texas have reduced herbivory when obtaining alkaloids from the hosts Lupinus argenteus and L. texensis (Fabaceae), respectively. However, pollinators were not deterred from visiting Castilleja parasitizing alkaloid-containing hosts. To determine if alkaloids are present in all tissues of plants parasitizing lupins, we analyzed floral tissue as well as leaves of both Castilleja species. ...

Abstract

Background and AimsCrop pollination by bees and other animals is an essential ecosystem service. Ensuring the maintenance of the service requires a full understanding of the contributions of landscape elements to pollinator populations and crop pollination. Here, the first quantitative model that predicts pollinator abundance on a landscape is described and tested. MethodsUsing information on pollinator nesting resources, floral resources and foraging distances, the model predicts the relative abundance of pollinators within nesting habitats. From these nesting areas, it then ...

Abstract

Yeasts are ubiquitous in terrestrial and aquatic microbiota, yet their ecological functionality remains relatively unexplored in comparison with other micro-organisms. This paper formulates and tests the novel hypothesis that heat produced by the sugar catabolism of yeast populations inhabiting floral nectar can increase the temperature of floral nectar and, more generally, modify the within-flower thermal microenvironment. Two field experiments were designed to test this hypothesis for the winter-blooming herb Helleborus foetidus (Ranunculaceae). In experiment 1, the effect of yeasts on the ...

Abstract

Ecological networks are complexes of interacting species, but not all potential links among species are realized. Unobserved links are either missing or forbidden. Missing links exist, but require more sampling or alternative ways of detection to be verified. Forbidden links remain unobservable, irrespective of sampling effort. They are caused by linkage constraints. We studied one Arctic pollination network and two Mediterranean seed-dispersal networks. In the first, for example, we recorded flower-visit links for one full season, arranged data in an interaction ...

Abstract

I studied the pollination biology of two closely related species of agave, Agave palmeri and A. chrysantha (Agavaceae), which exhibit several chiropterophilous (bat-pollinated) traits. Floral studies, floral visitor observations, and pollination studies were conducted over four summers at six different sites to examine floral traits and determine the relative importance of diurnal vs. nocturnal pollinators. Agave chrysantha appears to have developed minor shifts in several floral characters that enhance diurnal pollination. Although floral shifts towards diurnal pollination were fewer in A. ...

Abstract

Spatiotemporal variability in floral resources can have ecological and evolutionary consequences for both plants and the pollinators on which they depend. Seldom, however, can patterns of flower abundance and visitation in the field be linked with the behavioral mechanisms that allow floral visitors to persist when a preferred resource is scarce. To explore these mechanisms better, we examined factors controlling floral preference in the hawkmoth Manduca sexta in the semiarid grassland of Arizona. Here, hawkmoths forage primarily on flowers of the ...

Abstract

Despite recent interest in the non-sugar components of floral nectar, nearly nothing is known about the ecological importance and phylogenetic distribution of scented nectar. If present, the scent of nectar would provide an honest signal to nectar-feeding animals. Nectar odors may directly impact plant reproductive fitness, through pollinator attraction or deterrence of nectar robbers and florivores. In addition, nectar odors may indirectly impact plant fitness through antimicrobial activity, pleiotropic interactions with plant defense, and communication with predators and parasitoids. The literature ...

Abstract

Understanding how the distribution and abundance of food resources influence space use of organisms is an important element of successful conservation and recovery strategies for endangered species. We investigated interrelationships between space use, activity patterns, and food resources for lesser long-nosed bats (Leptonycteris curasoae), an endangered nectar-feeding bat, during an energetically demanding phase of its annual life cycle. We estimated the size of home ranges (95% kernel areas) and core use-areas (50% kernel areas) of bats and estimated density of their ...