DIVERSITÉ ET ACTIVITÉ DE BUTINAGE DES ABEILLES (HYMENOPTERA APOIDEA) DANS UNE PELOUSE À THÉROPHYTES DE CONSTANTINE (ALGÉRIE)

1998 ◽  
Vol 130 (5) ◽  
pp. 691-702 ◽  
Author(s):  
K. Louadi ◽  
S. Doumandji
Keyword(s):  
Apis Mellifera ◽  
Diversity Index ◽  
Flight Activity ◽  
Natural Vegetation ◽  
Wild Bees ◽  
Minimum Threshold ◽  
Bee Diversity ◽  
Bombus Ruderatus ◽  
Total Fauna ◽  
Shannon’S Diversity Index

AbstractThe study of bee diversity and activity was conducted from January until June 1994 in a natural vegetation parcel (6200 m2) in Constantine (Algeria). The results showed the presence of 10 genera of wild bees visiting natural flowers and belonging to four families: Andrenidae, Anthophoridae, Halictidae, and Megachilidae. The Apidae family was represented by honeybee (Apis mellifera L.) and bumblebee (Bombus ruderatus siculus Dalla Torre et Friese). Census of bee populations revealed the abundance of wild bees with 66.26% of flowers visits, honeybee with 31.98%, B. ruderatus and Xylocopa violacea with 1.59 and 0.17% of total fauna, respectively. The beginning flight activity of these species started from a minimum threshold of temperature and humidity. The alimentary specialization was quantified by Simpson’s diversity index (Is) and by Shannon’s diversity index (Ish). Apis mellifera had the highest floral visits index (Is = 0.866) and the broadest alimentary niche index (Ish = 0.316).

scholarly journals High honeybee abundances reduce wild bee abundances on flowers in the city of Munich

Oecologia ◽  
2021 ◽  
Author(s):  
Susanne S. Renner ◽  
Marie Sophie Graf ◽  
Zoe Hentschel ◽  
Helen Krause ◽  
Andreas Fleischmann
Keyword(s):  
Apis Mellifera ◽  
Adjacent Area ◽  
Exploitative Competition ◽  
Wild Bees ◽  
European Cities ◽  
Urban Garden ◽  
Wild Bee ◽  
June July ◽  
The City ◽  
Clear Support

AbstractThe increase in managed honeybees (Apis mellifera) in many European cities has unknown effects on the densities of wild bees through competition. To investigate this, we monitored honeybees and non-honeybees from 01 April to 31 July 2019 and 2020 at 29 species of plants representing diverse taxonomic and floral-functional types in a large urban garden in the city of Munich in which the same plant species were cultivated in both years. No bee hives were present in the focal garden, and all bee hives in the adjacent area were closely monitored by interviewing the relevant bee keepers in both 2019 and 2020. Honeybee numbers were similar in April of both years, but increased from May to July 2020 compared to 2019. The higher densities correlated with a significant increase in shifts from wild bee to honeybee visits in May/June/July, while visitor spectra in April 2019 and 2020 remained the same. Most of the species that experienced a shift to honeybee visits in 2020 were visited mostly or exclusively for their nectar. There were no shifts towards increased wild bee visits in any species. These results from a flower-rich garden have implications for the discussion of whether urban bee keeping might negatively impact wild bees. We found clear support that high honeybee densities result in exploitative competition at numerous types of flowers.

scholarly journals Improving Habitat Quality at the Local and Landscape Scales Increases Wild Bee Assemblages and Associated Pollination Services in Apple Orchards in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Panlong Wu ◽  
Piaopiao Dai ◽  
Meina Wang ◽  
Sijie Feng ◽  
Aruhan Olhnuud ◽  
...  
Keyword(s):  
Management Practices ◽  
Ground Cover ◽  
Agricultural Landscapes ◽  
Wild Bees ◽  
Natural Habitats ◽  
Pollination Services ◽  
Wild Bee ◽  
Wide Range ◽  
Bee Diversity ◽  
Landscape Scales

Bees provide key pollination services for a wide range of crops. Accumulating evidence shows the effect of semi-natural habitats at the landscape level and local management practices on bee diversity in fields. However, most of the evidence is derived from studies in North America and Europe. Whether this paradigm is applicable in China, which is characterized by smallholder-dominated agricultural landscapes, has rarely been studied. In this study, we aimed to investigate how bee diversity affected apple production, and how landscape and local variables affected bee diversity and species composition on the Northern China Plain. The results showed that bees significantly increased apple fruit set compared to bagged controls. Wild bee diversity was positively related to apple seed numbers. Higher seed numbers reduced the proportion of deformed apples and thus increased fruit quality. Wild bee abundance was positively correlated with flowering ground cover, and both the abundance and species richness of wild bees were positively affected by the percentage of semi-natural habitats. We conclude that apple quality can benefit from ecological intensification comprising the augmentation of wild bees by semi-natural habitats and flowering ground cover. Future pollination management should therefore reduce the intensification level of management at both the local and landscape scales.

scholarly journals Biodiversity and distribution of arbuscular mycorrhizal fungi in Araucaria angustifolia forest

2007 ◽  
Vol 64 (4) ◽  
pp. 393-399 ◽  
Author(s):  
Milene Moreira ◽  
Dilmar Baretta ◽  
Siu Mui Tsai ◽  
Sandra Maria Gomes-da-Costa ◽  
Elke Jurandy Bran Nogueira Cardoso
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Biological Diversity ◽  
Diversity Index ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Araucaria Angustifolia ◽  
Forest Sustainability ◽  
Shannon’S Diversity Index

Araucaria angustifolia (Bert.) O. Ktze. is an endangered Brazilian coniferous tree that has been almost exterminated in the native areas because of uncontrolled wood exploitation. This tree has been shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) and, therefore, AMF may be essential for forest sustainability and biological diversity. Root colonization, density and diversity of AMF spores were assessed in two Araucaria forest stands at the State Park of Alto Ribeira (PETAR), at two sampling dates: May and October. A comparison was made between a mature native stand composed of Araucaria trees mixed into a variety of tropical trees and shrubs, without any sign of anthropogenic interference (FN) and an Araucaria stand planted in 1987 (R), which has been used as a pasture. Assessments included percent root colonization, AMF spore numbers and species richness, Simpson's dominance index (Is), and Shannon's diversity index (H). Mycorrhizal root colonization did not differ between ecosystems in May. In October, however, the native stand (FN) presented a higher colonization than the planted forest (R), and the root colonization was more intense than in May. When considering both sampling periods and forests, 27 species of AM fungi, with higher numbers of spores in FN than in R were found. Canonical discriminant analysis (CDA) indicated Shannon's diversity index as the ecological attribute that contributed the most to distinguish between forest ecosystems, with higher value of H in FN in relation to R. CDA showed to be a useful tool for the study of ecological attributes.

Economic trade-offs of managing forests for timber production and vegetative diversity

1994 ◽  
Vol 24 (6) ◽  
pp. 1260-1265 ◽  
Author(s):  
David N. Holland ◽  
Robert J. Lilieholm ◽  
David W. Roberts ◽  
J. Keith Gilless
Keyword(s):  
Diversity Index ◽  
Basal Area ◽  
Timber Harvest ◽  
Forest Stand ◽  
Timber Production ◽  
Harvest Scheduling ◽  
Scheduling Model ◽  
Trade Offs ◽  
Compositional Diversity ◽  
Shannon’S Diversity Index

Three indices of forest stand structural and compositional diversity were incorporated into a linear programming timber harvest scheduling model to examine the trade-offs between managing stands for timber production and biodiversity objectives. The indices, based on Shannon's diversity index, characterized stand species diversity, basal area diversity, and vertical crown diversity. While harvest-level objectives were often compatible with the maintenance of vegetative diversity, the maximization of present net value was accompanied by substantial reductions in all three measures of diversity.

Pollinator communities in strawberry crops – variation at multiple spatial scales

2015 ◽  
Vol 105 (4) ◽  
pp. 497-506 ◽  
Author(s):  
E.J. Ahrenfeldt ◽  
B.K. Klatt ◽  
J. Arildsen ◽  
N. Trandem ◽  
G.K.S. Andersson ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Body Size ◽  
General Pattern ◽  
Field Size ◽  
Field Margins ◽  
Wild Bees ◽  
Regional Patterns ◽  
Activity Density ◽  
Bee Diversity

AbstractPredicting potential pollination services of wild bees in crops requires knowledge of their spatial distribution within fields. Field margins can serve as nesting and foraging habitats for wild bees and can be a source of pollinators. Regional differences in pollinator community composition may affect this spill-over of bees. We studied how regional and local differences affect the spatial distribution of wild bee species richness, activity-density and body size in crop fields. We sampled bees both from the field centre and at two different types of semi-natural field margins, grass strips and hedges, in 12 strawberry fields. The fields were distributed over four regions in Northern Europe, representing an almost 1100 km long north-south gradient. Even over this gradient, daytime temperatures during sampling did not differ significantly between regions and did therefore probably not impact bee activity. Bee species richness was higher in field margins compared with field centres independent of field size. However, there was no difference between centre and margin in body-size or activity-density. In contrast, bee activity-density increased towards the southern regions, whereas the mean body size increased towards the north. In conclusion, our study revealed a general pattern across European regions of bee diversity, but not activity-density, declining towards the field interior which suggests that the benefits of functional diversity of pollinators may be difficult to achieve through spill-over effects from margins to crop. We also identified dissimilar regional patterns in bee diversity and activity-density, which should be taken into account in conservation management.

scholarly journals Diversity of Wild Bees along Elevational Gradient in an Agricultural Area in Central Java, Indonesia

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Imam Widhiono ◽  
Eming Sudiana ◽  
Darsono Darsono
Keyword(s):  
Species Diversity ◽  
Diversity Index ◽  
Elevational Gradient ◽  
High Elevation ◽  
Agricultural Area ◽  
Wild Bees ◽  
Central Java ◽  
Wiener Diversity Index ◽  
Pollinator Community ◽  
Study Sites

Increases in mean temperature affect the diversity and abundance of wild bees in agricultural ecosystems. Pollinator community composition is expected to change along an elevational gradient due to differences in the daily ambient temperature. This study investigated the diversity and abundance of wild bees in an agricultural area along an elevational gradient in Central Java, Indonesia. Wild bees were collected using a sweep net in 40 green bean (Phaseolus vulgaris) cultivation sampling locations at seven different elevations (8, 108, 224, 424, 644, 893, and 1017 m above sea level). Species diversity was determined using the Shannon–Wiener diversity index. We identified 932 individuals from 8 species of wild bee belonging to 3 families. The family Apidae was predominant, with 6 species, while only 1 species was found from each of Megachilidae and Halictidae. Across the study sites, diversity increased with increasing elevation (H′= 1.4,D= 0.25, andE= 0.78 at low elevation toH′= 2.04,D= 0.13, andE= 0.96 at high elevation), and higher numbers of species were found at middle and high elevations. Species richness and abundance increased linearly with increasing elevation, and species diversity was highest at middle elevations.

scholarly journals Influence of Spartina alterniflora invasion stages on macrobenthic communities on a tidal flat in Wenzhou Bay, China

2012 ◽  
Vol 60 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Bao-Ming Ge ◽  
Yi-Xin Bao ◽  
Hong-Yi Cheng ◽  
Dai-Zhen Zhang ◽  
Zhi-Yuan Hu
Keyword(s):  
Species Richness ◽  
Spartina Alterniflora ◽  
Tidal Flat ◽  
Diversity Index ◽  
Eastern China ◽  
Macrobenthic Communities ◽  
Initial Stage ◽  
Invasion Stage ◽  
Shannon’S Diversity Index ◽  
Spartina Alterniflora Invasion

Many coastal habitats in eastern China are being substantially altered by the invasion of Spartina alterniflora. The species richness, density, Margalef's diversity index (R) and Shannon's diversity index (H') of macrobenthic communities on a tidal flat in Wenzhou Bay, China, were analyzed with the factors of invasion stage and season, in 2007. A significant effect of invasion stage, season, and the interaction between them on communities was detected. The macrobenthic community was more complex in the patch of initial S. alterniflora invasion than in the patches of some other invasion stages. Macrobenthic communities were classified by cluster and ordination in accordance with the habitat character of the S. alterniflora invasion stage. Our research demonstrated that the S. alterniflora invasion stage affected the macrobenthic communities significantly. The results indicated that biodiversity increased in the initial stage of invasion (invasion age 1-2 years) and then decreased in the stage of invasion underway (invasion age 3-4 years) and in the stage of invasion completed (invasion age 5-6 years); this phenomenon was related to the change in the S. alterniflora canopy which accompanied the invasion stages.

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