The relative importance of pollinator abundance and species richness for the temporal variance of pollination services

Uncultivated field margins are important refugia for pollinating insects in agricultural landscapes. However, the spill-over of pollination services from field margins to adjacent crops is poorly understood. This study (i) examined the effects of landscape heterogeneity on pollinator occurrence in permanent field margins and pollinator visitation to adjacent mass-flowering turnip rape (Brassica rapa ssp. oleifera) in boreal agricultural landscapes, and (ii) tested whether pollinator abundance and species richness in field margins predict abundance and species richness of crop visitors. Pollinators visiting the crop were more affected by landscape heterogeneity than pollinators in adjacent margins. Species richness, total abundance, and the abundance of syrphid flies visiting the crop increased with increasing landscape heterogeneity, whereas, in field margins, landscape heterogeneity had little effect on pollinators. In field-dominated homogeneous landscapes, wild pollinators rarely visited the crop even if they occurred in adjacent margins, whereas in heterogeneous landscapes, differences between the two habitats were smaller. Total pollinator abundance and species richness in field margins were poor predictors of pollinator visitation to adjacent crop. However, high abundances of honeybees and bumblebees in margins were related to high numbers of crop visitors from these taxa. Our results suggest that, while uncultivated field margins help pollinators persist in boreal agricultural landscapes, they do not always result in enhanced pollinator visitation to the adjacent crop. More studies quantifying pollination service delivery from semi-natural habitats to crops in different landscape settings will help develop management approaches to support crop pollination.

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Disentangling the Ecological Determinants of Species and Functional Trait Diversity in Herb-Layer Plant Communities in European Temperate Forests

Forests ◽

10.3390/f12050552 ◽

2021 ◽

Vol 12 (5) ◽

pp. 552

Author(s):

Janez Kermavnar ◽

Lado Kutnar ◽

Aleksander Marinšek

Keyword(s):

Species Richness ◽

Species Composition ◽

Plant Communities ◽

Functional Trait ◽

Forest Stand ◽

Relative Importance ◽

Herb Layer ◽

Bud Bank ◽

Tree Species Composition ◽

Stand Characteristics

Forest herb-layer vegetation responds sensitively to environmental conditions. This paper compares drivers of both taxonomic, i.e., species richness, cover and evenness, and functional herb-layer diversity, i.e., the diversity of clonal, bud bank and leaf-height-seed plant traits. We investigated the dependence of herb-layer diversity on ecological determinants related to soil properties, climatic parameters, forest stand characteristics, and topographic and abiotic and biotic factors associated with forest floor structure. The study was conducted in different forest types in Slovenia, using vegetation and environmental data from 50 monitoring plots (400 m2 each) belonging to the ICP Forests Level I and II network. The main objective was to first identify significant ecological predictors and then quantify their relative importance. Species richness was strongly determined by forest stand characteristics, such as richness of the shrub layer, tree layer shade-casting ability as a proxy for light availability and tree species composition. It showed a clear positive relation to soil pH. Variation in herb-layer cover was also best explained by forest stand characteristics and, to a lesser extent, by structural factors such as moss cover. Species evenness was associated with tree species composition, shrub layer cover and soil pH. Various ecological determinants were decisive for the diversity of below-ground traits, i.e., clonal and bud bank traits. For these two trait groups we observed a substantial climatic signal that was completely absent for taxonomy-based measures of diversity. In contrast, above-ground leaf-height-seed (LHS) traits were driven exclusively by soil reaction and nitrogen availability. In synthesis, local stand characteristics and soil properties acted as the main controlling factors for both species and trait diversity in herb-layer communities across Slovenia, confirming many previous studies. Our findings suggest that the taxonomic and functional facets of herb-layer vegetation are mainly influenced by a similar set of ecological determinants. However, their relative importance varies among individual taxonomy- and functional trait-based diversity measures. Integrating multi-faceted approaches can provide complementary information on patterns of herb-layer diversity in European forest plant communities.

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Pollination Potential in Portugal: Leveraging an Ecosystem Service for Sustainable Agricultural Productivity

Land ◽

10.3390/land10040431 ◽

2021 ◽

Vol 10 (4) ◽

pp. 431

Author(s):

Caroline Wentling ◽

Felipe S. Campos ◽

João David ◽

Pedro Cabral

Keyword(s):

Land Management ◽

Management Practices ◽

Production Systems ◽

Local Level ◽

Well Being ◽

Food Sources ◽

Pollination Services ◽

Pollinator Abundance ◽

Study Results ◽

Administrative Boundary

As urbanization and agriculture increase worldwide, habitats and food sources for wild pollinators are often fragmented or destroyed. As wild pollinators contribute both resilience and variety to agricultural fields, it is desirable to implement land management practices that preserve their well-being and ability to contribute to food production systems. This study evaluates continental Portugal for its change in suitability to host bee’s pollinator species (Apis mellifera) from 1990 to 2018. It uses the InVEST crop pollination modeling tool and CORINE Land Cover, as well as parameterization to produce pollinator abundance and supply maps. These are generalized to municipality boundaries to provide actionable insights to farmers and policymakers and strengthen land management practices. It finds that the potential for pollination services is growing, with averages of both pollinator abundance and supply indices improving by 8.76% across the continental territory in 28 years. The study results are validated using another pollination index derived from a study that is based on expert opinion and field sampling in a sub-region of Portugal. This method of aggregation of model results and comparison of the percent difference by administrative boundary has the potential to better inform both policymakers and farmers about the pollination potential on a local level, as well as inspire interventions for future productivity.

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Interference competition pressure predicts the number of avian predators that shifted their timing of activity

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.0744 ◽

2018 ◽

Vol 285 (1880) ◽

pp. 20180744 ◽

Cited By ~ 1

Author(s):

Yifan Pei ◽

Mihai Valcu ◽

Bart Kempenaers

Keyword(s):

Species Richness ◽

Body Size ◽

Interference Competition ◽

Relative Importance ◽

Exploitation Competition ◽

Predator Species ◽

Avian Predator ◽

Avian Predators ◽

Time Partitioning ◽

Competition Pressure

Being active at different times facilitates the coexistence of functionally similar species. Hence, time partitioning might be induced by competition. However, the relative importance of direct interference and indirect exploitation competition on time partitioning remains unclear. The aim of this study was to investigate the relative importance of these two forms of competition on the occurrence of time-shifting among avian predator species. As a measure of interference competition pressure, we used the species richness of day-active avian predator species or of night-active avian predator species (i.e. species of Accipitriformes, Falconiformes and Strigiformes) in a particular geographical area (assemblage). As an estimate of exploitation competition pressure, we used the total species richness of avian predators in each assemblage. Estimates of the intensity of interference competition robustly predicted the number of Accipitriformes species that became crepuscular and the number of Strigiformes species that became day-active or strictly crepuscular. Interference competition pressure may depend on body size and on the total duration of the typical active period (day or night length). Our results support—to some extent—that smaller species are more likely to become time-shifters. Day length did not have an effect on the number of time-shifter species in the Accipitriformes. Among the large Strigiformes, more time-shifter species occur in areas where nights are shorter (i.e. where less of the typical time resource is available). However, in the small Strigiformes, we found the opposite, counterintuitive effect: more time-shifters where nights are longer. Exploitation competition may have had an additional positive effect on the number of time-shifters, but only in Accipitriformes, and the effect was not as robust. Our results thus support the interference competition hypothesis, suggesting that animals may have shifted their time of activity, despite phylogenetic constraints on the ability to do so, to reduce the costs of direct interactions. Our findings also highlight the influence of body size as a surrogate of competitive ability during encounters on time partitioning, at least among avian predators.

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Exploring the relationships between landscape complexity, wild bee species richness and reproduction, and pollination services along a complexity gradient in the Netherlands

Biological Conservation ◽

10.1016/j.biocon.2017.08.027 ◽

2017 ◽

Vol 214 ◽

pp. 312-319 ◽

Cited By ~ 17

Author(s):

Tibor Bukovinszky ◽

Joke Verheijen ◽

Susan Zwerver ◽

Esther Klop ◽

Jacobus C. Biesmeijer ◽

...

Keyword(s):

Species Richness ◽

The Netherlands ◽

Pollination Services ◽

Landscape Complexity ◽

Wild Bee

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The relative importance of evolutionary and environmental controls on broad-scale patterns of species richness in North America

Ecoscience ◽

10.1080/11956860.1999.11682546 ◽

1999 ◽

Vol 6 (3) ◽

pp. 329-337 ◽

Cited By ~ 57

Author(s):

Jeremy T. Kerr ◽

David J. Currie

Keyword(s):

Species Richness ◽

North America ◽

Relative Importance ◽

Environmental Controls ◽

Broad Scale

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The Dynamics of Bird Diversity in the New World

Systematic Biology ◽

10.1093/sysbio/syaa028 ◽

2020 ◽

Vol 69 (6) ◽

pp. 1180-1199 ◽

Cited By ~ 1

Author(s):

Antonin Machac

Keyword(s):

Species Richness ◽

New World ◽

Dominant Role ◽

Bird Diversity ◽

Biodiversity Hotspots ◽

Relative Importance ◽

Diversification Rates ◽

The Andes ◽

The Rich ◽

Over Time

Abstract Three prominent explanations have been proposed to explain the dramatic differences in species richness across regions and elevations, (i) time for speciation, (ii) diversification rates, and (iii) ecological limits. But the relative importance of these explanations and, especially, their interplay and possible synthesis remain largely elusive. Integrating diversification analyses, null models, and geographic information systems, I study avian richness across regions and elevations of the New World. My results reveal that even though the three explanations are differentially important (with ecological limits playing the dominant role), each contributes uniquely to the formation of richness gradients. Further, my results reveal the likely interplay between the explanations. They indicate that ecological limits hinder the diversification process, such that the accumulation of species within a region gradually slows down over time. Yet, it does not seem to converge toward a hard ceiling on regional richness. Instead, species-rich regions show suppressed, but continued, diversification, coupled with signatures of possible competition (esp. Neotropical lowlands). Conversely, species-poor, newly-colonized regions show fast diversification and weak to no signs of competition (esp. Nearctic highlands). These results held across five families of birds, across grid cells, biomes, and elevations. Together, my findings begin to illuminate the rich, yet highly consistent, interplay of the mechanisms that together shape richness gradients in the New World, including the most species-rich biodiversity hotspots on the planet, the Andes and the Amazon. [Biogeography; community; competition; macroevolution; phylogenetics; richness gradient.]

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Bee Visitation and Fruit Quality in Berries Under Protected Cropping Vary Along the Length of Polytunnels

Journal of Economic Entomology ◽

10.1093/jee/toaa037 ◽

2020 ◽

Vol 113 (3) ◽

pp. 1337-1346 ◽

Cited By ~ 4

Author(s):

Mark A Hall ◽

Jeremy Jones ◽

Maurizio Rocchetti ◽

Derek Wright ◽

Romina Rader

Keyword(s):

Wind Speed ◽

Fruit Quality ◽

Uv Light ◽

Fruit Shape ◽

Climatic Conditions ◽

Pollination Services ◽

Pollinator Abundance ◽

South Wales ◽

Berry Crops ◽

Bee Foraging

Abstract Wild and managed bees provide effective crop pollination services worldwide. Protected cropping conditions are thought to alter the ambient environmental conditions in which pollinators forage for flowers, yet few studies have compared conditions at the edges and center of growing tunnels. We measured environmental variables (temperature, relative humidity, wind speed, white light, and UV light) and surveyed activity of the managed honey bee, Apis mellifera L.; wild stingless bee, Tetragonula carbonaria Smith; and wild sweat bee, Homalictus urbanus Smith, along the length of 32 multiple open-ended polyethylene growing tunnels. These were spaced across 12 blocks at two commercial berry farms, in Coffs Harbour, New South Wales and Walkamin, North Queensland, Australia. Berry yield, fresh weight, and other quality metrics were recorded at discrete increments along the length of the tunnels. We found a higher abundance and greater number of flower visits by stingless bees and honey bees at the end of tunnels, and less frequent visits to flowers toward the middle of tunnels. The center of tunnels experienced higher temperatures and reduced wind speed. In raspberry, fruit shape was improved with greater pollinator abundance and was susceptible to higher temperatures. In blueberry, per plant yield and mean berry weight were positively associated with pollinator abundance and were lower at the center of tunnels than at the edge. Fruit quality (crumbliness) in raspberries was improved with a greater number of visits by sweat bees, who were not as susceptible to climatic conditions within tunnels. Understanding bee foraging behavior and changes to yield under protected cropping conditions is critical to inform the appropriate design of polytunnels, aid pollinator management within them, and increase economic gains in commercial berry crops.

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Lung-worms (Nematoda: Pseudaliidae) of harbour porpoises (Phocoena phocoena) in Norwegian waters: patterns of colonization

Parasitology ◽

10.1017/s0031182000076186 ◽

1994 ◽

Vol 108 (3) ◽

pp. 343-349 ◽

Cited By ~ 5

Author(s):

J. A. Balbuena ◽

P. E. Aspholm ◽

K. I. Andersen ◽

A. Bjørge

Keyword(s):

Species Richness ◽

Marine Species ◽

Harbour Porpoise ◽

Relative Importance ◽

Host Age ◽

Phocoena Phocoena ◽

Component Community ◽

Terrestrial Species ◽

Lung Worms

SUMMARYWe studied the component community of lung-worms of the harbour porpoise, attempting to establish the relative importance of ecological and evolutionary factors on its development. The lungs of 64 porpoises by-caught in Norwegian waters were examined for helminths. Three pseudaliid species were detected. The porpoises appear to be readily colonized by lung-worms, the structure of the component community of calves being fairly similar to that of the remainder. Prenatal and/or transmammary infections might partly account for these early infections. However, host age was correlated with the number of lung-worm species, suggesting that the lung-worms may have heteroxenous cycles similar to other metastrongyloids. The lung-worm species tended to co-occur more often than expected by chance. This pattern is commonly observed in communities formed by phylogenetic relatives. Mean species richness of lung nematodes differed significantly among mammalian orders. However, species richness of marine species seemed very similar to those of most terrestrial species. This evidence suggests that phylogenetic factors seem more important than ecological ones in determining the number of lung-worm species in mammals.

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Powerline right-of-way management and flower-visiting insects: How vegetation management can promote pollinator diversity

PLoS ONE ◽

10.1371/journal.pone.0245146 ◽

2021 ◽

Vol 16 (1) ◽

pp. e0245146

Author(s):

Laura Russo ◽

Hannah Stout ◽

Dana Roberts ◽

Bradley D. Ross ◽

Carolyn G. Mahan

Keyword(s):

Species Richness ◽

Low Cost ◽

Vegetation Management ◽

Herbicide Application ◽

Pollinator Abundance ◽

Periodic Maintenance ◽

Negative Effect ◽

Low Levels ◽

Bee Community ◽

Flower Visiting

Loss in the availability of early successional habitat is a threat to pollinator populations. Given that powerline rights-of-way (ROW) must be managed to maintain early successional habitat, preventing vegetation from interfering with electrical lines, they have the potential to provide conservation benefits for wild pollinators. Moreover, it is possible to provide conservation benefits with no additional cost to land managers. We surveyed flower-visiting insects over two years in different vegetation management treatments in a long-term research ROW to determine which best promoted pollinator abundance and species richness. We found that the ROW had stabilized in an early successional state soon after its establishment and that this early successional state could be maintained with low levels of periodic maintenance. We collected a high diversity of flower-visiting insects (126 bee species and 179 non-bee morphospecies) in six ROW plots. Higher levels of herbicide application had a negative effect on bee species richness, but low levels of herbicide application were compatible with a high abundance and species richness of flower-visiting insects, including several rare species. Moreover, this effect was seen only in the bee community, and not in non-bee flower-visiting insects. Our results suggest further research into the conservation value of ROW for pollinators is warranted. We demonstrate that there is substantial potential for pollinator conservation in ROW, compatible with low-cost vegetation management.

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