Effects of flowering plant's patch size on species composition of pollinator communities, foraging strategies, and resource partitioning in bumblebees (Hymenoptera: Apidae)

Oecologia ◽  
1989 ◽  
Vol 78 (4) ◽  
pp. 550-558 ◽  
Author(s):  
Peter Sowig
Keyword(s):  
Species Composition ◽  
Resource Partitioning ◽  
Patch Size ◽  
Foraging Strategies

scholarly journals A PAISAGEM COMO CONDICIONADORA DE BORDAS DE FRAGMENTOS FLORESTAIS

FLORESTA ◽  
2005 ◽  
Vol 35 (1) ◽  
Author(s):  
Bethania Cristiane Herrmann ◽  
Efraim Rodrigues ◽  
André De Lima
Keyword(s):  
Species Composition ◽  
Patch Size ◽  
Nearest Neighbor ◽  
Core Area ◽  
Forest Fragments ◽  
Spatial Structures ◽  
Landscape Index ◽  
Area Index ◽  
Components Analysis ◽  
The Relationship

Fragmentos florestais diferem em sua estrutura espacial afetando a composição de espécies em suas bordas. O objetivo deste trabalho foi analisar a influência dos índices da paisagem sobre as bordas de fragmentos florestais próximos à cidade de Londrina - PR. As características estruturais dos fragmentos aqui consideradas incluem área, forma, área central e índice de área central; e as características estruturais da paisagem: área da classe, tamanho médio e coeficiente de variação do tamanho dos fragmentos de floresta, distância média até o fragmento florestal mais próximo e total de bordas de floresta. A relação entre composição de espécies, fragmentos florestais e índices de paisagem foi estudada através de Análise de Correspondência Canônica. Os índices de maior importância foram: área, forma e área central dos fragmentos. Godoy, fragmento com 2371,14 ha e inclui o Parque Estadual Mata dos Godoy, apresentou maior variação na composição de espécies quando comparado com os demais. The landscape as conditioning of edges of forest fragments Abstract Forests fragments differ in their spatial structure afecting the species composition of edges. The objective of this paper was to analyze the influence of some landscape index over sapling species composition in edges of forests fragments near Londrina - PR. The spatial structures of fragments considered in this paper involved area, shape, core area and core area index; and the spatial structures of landscape: class area, mean patch size, coefficient of variation of the size of the patch (%), mean nearest neighbor distance and total edge of forest. The relationship between sapling species composition, forests fragments and landscape index were evaluated through Principal Components Analysis. Godoy, fragment with 2371,14 ha showed more variation in the species composition when compared with other fragments.

scholarly journals Habitat Specificity Modulates the Response of Small Mammals to Habitat Fragmentation, Loss, and Quality in a Neotropical Savanna

2021 ◽  
Vol 9 ◽  
Author(s):  
Ingrid de Mattos ◽  
Bárbara Zimbres ◽  
Jader Marinho-Filho
Keyword(s):  
Species Composition ◽  
Functional Diversity ◽  
Habitat Loss ◽  
Habitat Quality ◽  
Small Mammals ◽  
Small Mammal ◽  
Patch Size ◽  
Landscape Configuration ◽  
Habitat Amount ◽  
Habitat Generalists

Landscape conversion of natural environments into agriculture and pasture are driving a marked biodiversity decline in the tropics. Consequences of fragmentation might depend upon habitat amount in the landscape, while the quality of remnants can also affect some species. These factors have been poorly studied in relation to different spatial scales. Furthermore, the impacts of these human-driven alterations may go beyond species loss, possibly causing a loss of ecosystem function and services. In this study, we investigated how changes in landscape configuration (patch size and isolation), habitat loss (considering a landscape gradient of 10, 25, and 40% of remnant forest cover), and habitat quality (forest structure) affect small mammal abundance, richness, taxonomic/functional diversity, and species composition in fragmented landscapes of semideciduous forests in the Brazilian Cerrado. Analyses were performed separately for habitat generalists and forest specialists. We live-trapped small mammals and measured habitat quality descriptors four times in 36 forest patches over the years 2018 and 2019, encompassing both rainy and dry seasons, with a total capture effort of 45,120 trap-nights. Regression analyses indicated that the effect of landscape configuration was not dependent on the proportion of habitat amount in the landscape to determine small mammal assemblages. However, both patch size and habitat loss impacted different aspects of the assemblages in distinct ways. Smaller patches were mainly linked to an overall increase in small mammal abundance, while the abundance of habitat generalists was also negatively affected by habitat amount. Generalist species richness was determined by the proportion of habitat amount in the landscape. Specialist richness was influenced by patch forest quality only, suggesting that species with more demanding habitat requirements might respond to fragmentation and habitat loss at finer scales. Taxonomic or functional diversity were not influenced by landscape structure or habitat quality. However, patch size and habitat amount in the landscape were the major drivers of change in small mammal species composition in semideciduous forests in the Brazilian savanna.

scholarly journals Level of urbanization and habitat type, and not patch size, influence predacious arthropod diversity patterns of urban grasslands in South Africa

2021 ◽  
Vol 22 (9) ◽  
Author(s):  
Bianca Greyvenstein ◽  
Monique Botha ◽  
Johnnie Van den Berg ◽  
Stefan Siebert
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Species Composition ◽  
Patch Size ◽  
Habitat Type ◽  
Arthropod Diversity ◽  
Diversity Patterns ◽  
Urban Green ◽  
Arthropod Species ◽  
African Perspective

Abstract. Greyvenstein B, Botha M, van den Berg J, Siebert SJ. 2021. Level of urbanization and habitat type, and not patch size, influence predacious arthropod diversity patterns of urban grasslands in South Africa. Biodiversitas 22: 4078-4094. Predacious arthropods provide a valuable ecosystem service within urban environments by suppressing pest numbers. However, urban ecological studies largely ignore this functional group and its diversity and species composition patterns. Some studies have been published regarding these patterns, however they were mostly done in Australia, Europe and America, thus an African perspective is lacking. Our aim was to address the gap in African literature by quantify the differences in predacious arthropod species richness and diversity within urban green space in varying urbanization intensities, habitat types of grassland and patch sizes in South Africa. Various indices were considered to examine the effect of urbanization on the diversity patterns of Chrysopidae (Neuroptera), Mantodea, Araneae and Coccinellidae (Coleoptera). Study sites included three levels of urbanization represented by population density, two types of urban grasslands (i.e., ruderal and fragmented grassland) and a peri-urban rangeland grassland as control, and a wide range of patch sizes. Our results indicated that an increase in urbanization intensities was associated with increased abundance of predacious arthropod taxa. Also, that urban and peri-urban grasslands had similar predacious arthropod species richness and diversity, but differed in species composition. No relationship was found between patch size and arthropod diversity or composition. Thus, predacious arthropod abundances are influenced by the level of urbanization and their species composition is influenced by the type of urban grassland (ruderal or fragmented), which are important considerations for future urban planning/management and conservation strategies. This study gives a South African perspective and indicates that despite the lack of assigned function of urban green spaces, they sustain diverse and distinct predacious arthropod communities, which in turn fulfill various roles in a functioning ecosystem.

scholarly journals Species-specific foraging strategies of the syntopical and synchronous bees Panurgus calcaratus (Scopoli, 1763) and Dasypoda hirtipes (Fabricius, 1793) (Hymenoptera: Apidae).

2000 ◽  
Vol 50 (1) ◽  
pp. 179-191
Author(s):  
Eva-Maria Levermann ◽  
Inge Bischoff ◽  
Thomas Wagner
Keyword(s):  
Optimal Foraging ◽  
Resource Partitioning ◽  
Foraging Strategies ◽  
Separation Mechanisms ◽  
Species Specific

Die Sammelstrategie der beiden endogäischen, oligolektischen syntop und synchron auftretenden Wildbienenarten Panurgus calcaratus (Scopoli, 1763) und Dasypoda hirtipes (Fabricius, 1793) wurden im Naturschutzgebiet Wahner Heide (Rheinland, BRD) untersucht. Saisonale und diurnale Rhythmik sowie die Sammelstrategien beider Arten wurden erfaßt, um eventuell bestehende Trennungsmechanismen oder Nischendiffenzierung aufzudecken. Neben dem Verproviantierungsverhalten der Bienen wurde die Oligolektie durch Pollenentnahme von Weibchen und durch Beobachtung an den Pollenquellen überprüft. Beide Arten nutzen ausschließlich gelbe, photonastische, zungenblütige Asteraceae als Pollenquellen, präferieren sandige Flächen mit geringer Vegetation als Nistplatz und sind von Anfang Juli bis Ende August aktiv. Eine Spezialisierung innerhalb der Oligolektie auf einzelne Arten zungenblütiger Asteraceae konnte nicht erkannt werden. Dasypoda hirtipes wies eine allgemein längere diurnale Aktivität auf und war zudem auch bei geringeren Temperaturen noch aktiv. Die Pollensammelaktivitäten werden bei beiden Arten maßgeblich von den photonastischen Pollenquellen limitiert. Desweiteren ist die Bienenaktivität von klimatischen Faktoren wie Lichtintensität, Bewölkung und Lufttemperatur abhängig. Artspezifische diurnale und saisonale Verhaltensweisen und Aktivitätsrhythmen werden im Hinblick auf Körpergröße und -farbe, Hitzeabsorptions- und Reflektions-Fähigkeit, Überhitzungsgefahr sowie Effekte der Ekto- und Heterothermie auf den Wärmehaushalt diskutiert. Jede Art verfolgt eine eigene Sammelstrategie, welche hauptsächlich durch ultimative Faktoren wie die Physiologie der jeweiligen Bienenart beeinflußt und zugleich limitiert wird. Weder Nistplatzangebot noch die Ressourcen Pollen oder Nektar sind im Untersuchungsgebiet begrenzt, so daß keine Evidenz für Konkurrenz zwischen den beiden Arten besteht.StichwörterInterspecific competition, oligolecty, optimal foraging strategies, photonasty, resource partitioning, separation mechanisms.

scholarly journals Relación especie-área y distribución de la abundancia de especies en una comunidad vegetal de un inselberg tropical: efecto del tamaño de los parches

2018 ◽  
Vol 66 (2) ◽  
pp. 937 ◽  
Author(s):  
Pedro Manuel Villa ◽  
Lucas De Siqueira Cardinelli ◽  
Luiz Fernando Magnago ◽  
Gustavo Heringer ◽  
Sebastião Venâncio Martins ◽  
...  
Keyword(s):  
Species Composition ◽  
Plant Community ◽  
Community Assembly ◽  
Patch Size ◽  
Species Abundance ◽  
Species Abundance Distribution ◽  
Abundance Distribution ◽  
Species Area ◽  
Best Fit ◽  
Vegetation Patches

Species-area relation and species abundance distribution in a plant community on a tropical inselberg: effect of patch size. Although inselbergs are iconic rock outcrops with a high biogeographic value, little is known about drivers responsible for the plant community assembly. The aim of this research was to evaluate how the patch size distribution of vegetation influences the species-area relationship and species abundance distribution of a community in an inselberg of the “Piedra La Tortuga” Natural Monument of the Guayana region, Venezuela. In this context, three research questions were established: What is the effect of patch size on species richness? What species-area model (SAR) has the best fit in those vegetation patches? How is the distribution of species abundances (SADs) induced by the patch size distribution? A stratified random sampling was performed in patches ranging from 0.34 to 14.8 m2, totaling 40 sampling units (226 m2). All individuals found in the 40 patches were identified at species level. The floristic composition in the different samples was represented by 19 families, 22 genera and 24 species, of which 50 % are endemic to inselbergs and two, are threatened of extinction. Two groups of patch sizes were identified (large 8-15 m2 and small ≤ 7.9 m2) in relation to the abundance and composition of species. The species accumulation curves for each patch size group show a contrasting tendency with marked differences in the observed richness among patch size groups. The curves of the SADs models had a significant adjustment of the geometric series in the two categories of patches. The SAR model of the power function presented the best species-area adjustments, where the increase in patch area accounted for 82 % of the variation in the increase in the number of species. The results of this study demonstrate for the first time how vegetation patches of a tropical inselberg have a strong influence on richness, abundance distribution and species composition. Likewise, it was determined that the SAD geometric model presented the best fit in the community as a function of patch size as a resource indicator, where the abundance of a species can be equivalent to a proportion of the space occupied. It is also presumed that changes in patch sizes could be associated with nutrient and water availability, as has been demonstrated in other dryland environments. In some studies it has been argued that variation in species composition among vegetation profiles of tropical inselbergs is mainly conditioned by habitat structure and water deficit. However, it had not been discussed how the size of patches of vegetation has an effect on richness. SADs and SAR analyzes can provide complementary explanations on community assembly in inselbergs. Rev. Biol. Trop. 66(2): 937-951. Epub 2018 June 01. 

Influence of shelf oceanographic variability on alternate foraging strategies in long-nosed fur seals

2019 ◽  
Vol 615 ◽  
pp. 189-204 ◽  
Author(s):  
D Foo ◽  
C McMahon ◽  
M Hindell ◽  
S Goldsworthy ◽  
F Bailleul
Keyword(s):  
Foraging Strategies ◽  
Fur Seals
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