scholarly journals The context dependency of pollinator interference: how environmental conditions and species abundances impact floral visitation

2020 ◽  
Author(s):  
Alba Cervantes-Loreto ◽  
Carolyn Ayers ◽  
Emily Dobbs ◽  
Berry Brosi ◽  
Daniel Stouffer
Keyword(s):  
Experimental Data ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Pesticide Exposure ◽  
Context Dependency ◽  
Abiotic Conditions ◽  
Visitation Rates ◽  
Species Abundances ◽  
Floral Visitation ◽  
Different Levels

Pollinator foraging behavior determines floral visitation rates, an important proxy to the strength of mutual- istic interactions. Although there is evidence that pollinators modify their behavior in the presence of other foragers, there are equivocal findings regarding whether or not pollinators interfere with one another. We employ a functional-response framework to analyse experimental data of times between floral visits made by a focal pollinator and to estimate pollinator interference by conspecifics and three other species. Additionally we develop and compare models that allow different levels of resource availability and the sub-lethal exposure to a neonicotinoid pesticide to modify how pollinators forage alone and with co-foragers. We found that all co-foragers interfere with a focal pollinator under at least one set of abiotic conditions; for most species, interference was strongest at higher levels of resource availability and with pesticide exposure. Overall our results highlight that density-dependent responses are often context dependent themselves.

The context dependency of pollinator interference: How environmental conditions and co‐foraging species impact floral visitation

2021 ◽  
Author(s):  
Alba Cervantes‐Loreto ◽  
Carolyn A. Ayers ◽  
Emily K. Dobbs ◽  
Berry J. Brosi ◽  
Daniel B. Stouffer
Keyword(s):  
Environmental Conditions ◽  
Context Dependency ◽  
Floral Visitation

scholarly journals Effects of environmental conditions associated to the cardinal orientation on the reproductive phenology of the cerrado savanna tree Xylopia aromatica (Annonaceae)

2011 ◽  
Vol 83 (3) ◽  
pp. 1007-1020 ◽  
Author(s):  
Maria Gabriela G. Camargo ◽  
Regina M. Souza ◽  
Paula Reys ◽  
Leonor P.C. Morellato
Keyword(s):  
Edge Effects ◽  
Environmental Conditions ◽  
Fruit Production ◽  
Sensu Stricto ◽  
Southeastern Brazil ◽  
Reproductive Phenology ◽  
Canopy Openness ◽  
Cerrado Savanna ◽  
Cardinal Direction ◽  
Floral Visitation

The Brazilian cerrado has undergone an intense process of fragmentation, which leads to an increase in the number of remnants exposed to edge effects and associated changes on environmental conditions that may affect the phenology of plants. This study aimed to verify whether the reproductive phenology of Xylopia aromatica (Lam.) Mart. (Annonaceae) differs under different light conditions in a cerrado sensu stricto (a woody savanna) of southeastern Brazil. We compared the reproductive phenology of X. aromatica trees distributed on east and south cardinal faces of the cerrado during monthly observations, from January 2005 to December 2008. The east face had a higher light incidence, higher temperatures and canopy openness in relation to south face. X. aromatica showed seasonal reproduction at both faces of the cerrado, but the percentage of individuals, the synchrony and duration of phenophases were higher at the east face. The study demonstrated the influence of the environmental conditions associated to the cardinal orientation of the cerrado faces on the phenological pattern of X. aromatica. Similar responses may be observed for other species, ultimately affecting patterns of floral visitation and fruit production, which reinforces the importance of considering the cardinal direction in studies of edge effects and fragmentation.

Torsional characterization of ropes used offshore

2008 ◽  
Vol 43 (2) ◽  
pp. 121-139 ◽  
Author(s):  
I M L Ridge
Keyword(s):  
Experimental Data ◽  
Torsional Response ◽  
In Series ◽  
Different Levels

The first part of this paper presents a general discussion of the various problems which must be addressed when combining different ropes in series or, in some cases, in using a rope in conditions where it is rotationally unrestrained. The paper will pay particular attention to the various classes of rope used in the offshore environment and their main torsional characteristics. In the second part, equipment is shown which is suitable for the measurement of the torsional response of various rope constructions at different levels of twist. Experimental data are presented for a variety of rope constructions at sizes comparable with those used in offshore applications. Comparison is made with data obtained in similar previous studies but with smaller‐diameter ropes.

scholarly journals Measuring the modal parameters of a cultural heritage tower by using strong-motion signals

ACTA IMEKO ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 86 ◽  
Author(s):  
Mariella Diaferio ◽  
Dora Foti ◽  
Nicola Ivan Giannoccaro ◽  
Salvador Ivorra Ivorra
Keyword(s):  
Phase Shift ◽  
Environmental Conditions ◽  
Excitation Frequency ◽  
Strong Motion ◽  
Forced Vibrations ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Vibration Modes ◽  
Experimental Campaign ◽  
Different Levels

This paper presents the dynamic experimental campaign carried out on a stocky masonry clock tower situated in the Swabian Castle of Trani (Italy). The main objective of this paper is, after estimating the main frequencies and vibration modes of the considered structure, defining the transmission of vibrations along the height of the tower by varying the forced frequency at the base. At this aim, short acceleration records have been acquired simultaneously in 20 points of the tower at different levels, due to a series of sinusoidal forced vibrations applied at the base by using a pneumatic shaker device specify designed for the tests. The proposed procedure permit to extract for each monitored point the amplitude of the sinusoidal component related to the excitation frequency and the phase shift due to the structure damping. The results of the proposed procedure are compared with the results of a classical operational modal analysis in environmental conditions in order to demonstrate that the short forced tests permit to classify the typology of the structure mode shapes.

scholarly journals Genetic and no genetic variability of two-year old seedlings of 13 hybrid plane half-sib lines

2005 ◽  
pp. 69-85 ◽  
Author(s):  
Radmila Knezevic ◽  
Mirjana Sijacic-Nikolic
Keyword(s):  
Genetic Variability ◽  
Environmental Conditions ◽  
Hybrid Sterility ◽  
Soil Humidity ◽  
Frequent Mutations ◽  
Different Levels ◽  
Partial Hybrid

This paper presents the results of the analysis of variability of 8 analyzed morph metric parameters in two-year old seedlings of 13 half-sib lines at different levels. The recorded genetic and no genetic variability is conditioned by numerous different factors. The important causes of genetic variability are: partial incompatibility of parent trees, partial hybrid sterility, predominant inbreeding, frequent mutations with the growth of parent trees, very abundant gene recombination's, etc. The causes of no genetic seedling variability are: external environmental conditions (soil humidity, conditions of cultivation, sylvotechnical interventions, etc) and the internal or the somatic environment of seedling.

scholarly journals ‘Pre-Neolithic’ in Southeast Europe: a Bulgarian perspective

2014 ◽  
Vol 41 ◽  
pp. 95-109 ◽  
Author(s):  
Maria Gurova ◽  
Clive Bonsall
Keyword(s):  
Black Sea ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Balkan Peninsula ◽  
The Black Sea ◽  
Future Research ◽  
Upper Palaeolithic ◽  
Southeast Europe ◽  
Site Distribution

 This paper discusses why large areas of the central and northern Balkans lack evidence of Mesolithic settlement and what implications this holds for future research into the Neolithization of the region. A marked shift in site distribution patterns between Upper Palaeolithic and Mesolithic is interpreted as a response to changing environmental conditions and resource availability. It is suggested that some important questions of the pattern, processes and timing of the transition to farming across the Balkan Peninsula may only be answered through new archaeological surveys of the Lower Danube valley and exploration of submerged landscapes along the Black Sea, Aegean and Adriatic coasts.

Bioeroding sponge assemblages: the importance of substrate availability and sediment

2018 ◽  
Vol 99 (2) ◽  
pp. 343-358 ◽  
Author(s):  
Joseph Marlow ◽  
Christine H.L. Schönberg ◽  
Simon K. Davy ◽  
Abdul Haris ◽  
Jamaluddin Jompa ◽  
...  
Keyword(s):  
Coral Reef ◽  
Environmental Factors ◽  
Spatial Variation ◽  
Environmental Conditions ◽  
Sponge Species ◽  
Coral Mortality ◽  
Substrate Availability ◽  
Abiotic Conditions ◽  
Assemblage Composition ◽  
Reef Health

Despite global deterioration of coral reef health, not all reef-associated organisms are in decline. Bioeroding sponges are thought to be largely resistant to the factors that stress and kill corals, and are increasing in abundance on many reefs. However, there is a paucity of information on how environmental factors influence spatial variation in the distribution of these sponges, and how they might be affected by different stressors. We aimed to identify the factors that explained differences in bioeroding sponge abundance and assemblage composition, and to determine whether bioeroding sponges benefit from the same environmental conditions that can contribute towards coral mortality. Abundance surveys were conducted in the Wakatobi region of Indonesia on reefs characterized by different biotic and abiotic conditions. Bioeroding sponges occupied an average of 8.9% of available dead substrate and variation in abundance and assemblage composition was primarily attributed to differences in the availability of dead substrate. Our results imply that if dead substrate availability increases as a consequence of coral mortality, bioeroding sponge abundance is also likely to increase. However, bioeroding sponge abundance was lowest on a sedimented reef, despite abundant dead substrate. This suggests that not all forms of coral mortality will benefit all bioeroding sponge species, and sediment-degraded reefs are likely to be dominated by a few resilient bioeroding sponge species. Overall, we demonstrate the importance of understanding the drivers of bioeroding sponge abundance and assemblage composition in order to predict possible impacts of different stressors on reefs communities.

scholarly journals Inbred burying beetles suffer fitness costs from making poor decisions

2018 ◽  
Vol 285 (1881) ◽  
pp. 20180419 ◽  
Author(s):  
Jon Richardson ◽  
Pauline Comin ◽  
Per T. Smiseth
Keyword(s):  
Decision Making ◽  
Inbreeding Depression ◽  
Resource Availability ◽  
Environmental Conditions ◽  
Fitness Costs ◽  
Individual Decision ◽  
Burying Beetle ◽  
Individual Decision Making ◽  
Fitness Consequences ◽  
Nicrophorus Vespilloides

There is growing interest in how environmental conditions, such as resource availability, can modify the severity of inbreeding depression. However, little is known about whether inbreeding depression is also associated with differences in individual decision-making. For example, decisions about how many offspring to produce are often based upon the prevailing environmental conditions, such as resource availability, and getting these decisions wrong may have important fitness consequences for both parents and offspring. We tested for effects of inbreeding on individual decision-making in the burying beetle Nicrophorus vespilloides, which uses the size of a carrion resource to make decisions about number of offspring. Both inbred and outbred females adjusted their initial decisions about number of eggs to lay based on carcass size. However, when we forced individuals to update this initial decision by providing them with a different-sized carcass partway through reproduction, inbred females failed to update their decision about how many larvae to cull. Consequently, inbred females reared too many larvae, resulting in negative fitness consequences in the form of smaller offspring and reduced female post-reproductive condition. Our study provides novel insights into the effects of inbreeding by showing that poor decision-making by inbred individuals can negatively affect fitness.

Wavelet Transform Modulus Maxima Decay Lines

2015 ◽  
pp. 48-68
Author(s):  
Andreas Kyprianou ◽  
Andreas Tjirkallis
Keyword(s):  
Experimental Data ◽  
Wavelet Transform ◽  
Damage Detection ◽  
Environmental Conditions ◽  
Simulated Data ◽  
Random Excitation ◽  
Operating Conditions ◽  
Structural Behaviour ◽  
Operational Conditions ◽  
Three Degree Of Freedom

An important task in structural health monitoring (SHM) is that of damage detection under varying environmental and operational conditions. Structures, under varying environmental conditions, change their mass, elasticity and damping properties whereas changing operational conditions cause changes to excitations. A damage detection methodology implemented in these circumstances faces serious challenges since changes to structural behaviour imparted by environmental or operational conditions could be wrongly attributed to damage. The part of a damage detection decision algorithm that removes environmental and operational effects is called normalization. In this chapter a normalization methodology that is based on the similarity between continuous wavelet transform maxima decay lines is presented. This methodology is implemented on both simulated and experimental data. Simulated data were obtained from a three degree of freedom system. Varying environmental conditions were simulated by temperature dependent stiffness parameters and operating conditions by changing the colour of random excitation. Experimental data were obtained from damaged cantilever beams that were subjected to random excitations of different colour and varying temperatures.

Chert Resource Availability, Production, and Economic Logic

2020 ◽  
pp. 117-131
Author(s):  
Rachel A. Horowitz ◽  
Marcello Canuto ◽  
Chloé Andrieu
Keyword(s):  
Economic System ◽  
Resource Availability ◽  
Raw Materials ◽  
Social Hierarchy ◽  
Classic Maya ◽  
Local Market ◽  
Ancient Maya ◽  
Production And Distribution ◽  
Basic Level ◽  
Different Levels

At a basic level, the lowland Classic Maya economy was a complex web of prestige exchange, centralized distribution, and local market economies. While it is important not to consider the lowland Classic Maya economic system as monolithic, it is also as critical to understand how it articulated with the different levels of social hierarchy. In this chapter, we address the distribution of utilitarian goods in the ancient Maya economy through comparisons of lithic resources, particularly chert, in northwestern Petén and western Belize. We find that access to locally available raw materials affects the involvement of actors of differing sociopolitical status in lithic production and distribution.

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