scholarly journals STRUCTURAL COMPLEXITY OF ARTIFICIAL HABITAT AND THE FEEDING SUCCESS OF PREDATORY DRAGONFLY AND DAMSELFLY

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Khairuddin, Lalu Japa Dan Nur Lestari
Keyword(s):  
Habitat Complexity ◽  
Habitat Structure ◽  
Simple Structure ◽  
Complex Structure ◽  
Structural Complexity ◽  
Artificial Habitat ◽  
Artificial Habitats ◽  
Feeding Success ◽  
Structure Complexity

AbstractThe effect of different habitat complexity structure on the feeding success of predatoryDragonfly and Damselfly over the four of three hours trials was tested using an artificialhabitat complexity structure. Complexity of artificial habitat structure was performed usingwoody bamboo stick of 5 cm in length and 2 mm in diameter. The artificial habitats were setin plastic tank with length and wide of 17 cm and 11.5 cm, respectively and 5.5 cm high. Thedeep of water colom was about 4.5 cm. Preys were larvae of mosquitoes. There was highlysignificant of feeding success of predators in simple structure of habitats and significantenough in complex structure of habitats. In other words, feeding success of predatoryDragonfly and Damselfly was much higher in the simple habitats structure compared to thatof the complex one.Key Words : Artificial Habitat, Damselfly, Dragonfly, Feeding, and PredatoryAbstrakPengaruh kompleksitas struktur habitat terhadap keberhasilan pemangsaan predator Dragonflydan Damselfly selama empat kali tiga jam perlakuan diteliti di laboratorium menggunakanhabitat buatan. Kompleksitas struktur habitat dibuat dengan tongkat dari bambu berukuranpanjang 5 cm dengan diameter 2 mm. Habitat buatan dibuat di bak plastik berukuran panjangdan lebar masing-masing 17 cm dan 11,5 cm, dan tinggi 5,5 cm dengan kedalaman kolom airsekitar 4,5 cm. Larva nyamuk digunakan sebagai pangsa dalam penelitian ini. Setiapperlakuan terdiri dari dua ulangan. Setiap perlakuan berlangsung empat kali masing-masingselama tiga jam. Hasil memperlihatkan, keberhasilan pemangsaan Dragonfly dan Damselflysangat signifikan pada habitat stuktur sederhana, dan cukup signifikan pada habitat yangkompleks. Dengan kata lain, keberhasilan pemangsaan Dragonfly dan Damselfly jauh lebihtinggi pada habitat berstruktur sederhana dibanding dengan pada habitat berstrukturkompleks.Kata Kunci : Damselfly, Draggonfly, Habitat Buatan, Pemangsaan, Pemangsa (Predator)

scholarly journals Grazing by large savanna herbivores indirectly alters ant diversity and promotes resource monopolisation

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6226 ◽  
Author(s):  
Jean Purdon ◽  
Catherine L. Parr ◽  
Michael J. Somers
Keyword(s):  
Body Size ◽  
Habitat Complexity ◽  
Habitat Structure ◽  
Foraging Behaviour ◽  
Layer Structure ◽  
Structural Complexity ◽  
Structure And Function ◽  
Bunch Grass ◽  
And Function ◽  
Ant Diversity

In savannas, grazing is an important disturbance that modifies the grass layer structure and composition. Habitat structural complexity influences species diversity and assemblage functioning. By using a combination of natural sites and manipulated experiments, we explored how habitat structure (grazing lawns and adjacent bunch grass) affects ant diversity and foraging behaviour, specifically the efficiency of resource acquisition, resource monopolisation and ant body size. We found that in the natural sites there was no difference in the amount of time ants took to locate resources, but in the manipulated experiments, ants were faster at locating resources and were more abundant in the simple treatments than in the more complex treatments. Ant body size was only affected by the manipulated experiments, with smaller ants found in the more complex treatments. In both the grazing lawn and bunch grass habitats there were differences in assemblage patterns of ants discovering resources and those dominating them. Seasonality, which was predicted to affect the speed at which ants discovered resources and the intensity of resource monopolisation, also played a role. We show that ants in winter monopolised more baits and discovered resources at a slower rate, but only at certain times within the experiment. Grazing in conjunction with season thus had a significant effect on ant diversity and foraging behaviour, with dominant ants promoted where habitat complexity was simplified when temperatures were low. Our results indicate that structural complexity plays a major role in determining ant assemblage structure and function in African savannas.

scholarly journals Effects of land abandonment and changing habitat structure on avian assemblages in upland pastures of Bulgaria

2009 ◽  
Vol 20 (2) ◽  
pp. 200-213 ◽  
Author(s):  
STOYAN C. NIKOLOV
Keyword(s):  
Habitat Complexity ◽  
Habitat Structure ◽  
Structural Characteristics ◽  
Conservation Status ◽  
Grassland Birds ◽  
Bird Species ◽  
Structural Complexity ◽  
Bird Community ◽  
Bird Species Richness ◽  
Point Count

SummaryOver the past half century, grassland birds in Europe have declined dramatically and in order to maintain and restore their populations it is critical to understand how habitat structures and quality within pastures affect birds. This study investigated the effects of habitat structure and pasture abandonment on grassland birds in IBA Ponor, western Bulgaria. Birds were sampled using the point count method at 143 randomly located circular plots and a total of 1,401 observations of birds from 31 species were recorded. The results showed that habitat complexity, management and landscape position influenced bird community structure and species occurrence within the upland pastures. Extensively grazed pastures supported higher structural complexity of vegetation cover and higher bird-species richness and diversity compared with abandoned ones. Moreover, bird species with a preference for grazed rather than abandoned pastures had higher conservation status and most were associated with shrub cover. To maintain high levels of avian diversity, habitat complexity within pastures should be maintained through extensive grazing, to ensure availability of scrub vegetation wherever possible. Finally, this study provided evidence that agri-environmental schemes should not be directly extrapolated from one country or region to another without been tested first, because within the same management, differences in habitat structural characteristics may exist due to the landscape and socio-economic characteristics of the region.

scholarly journals Methyl phenlactonoates are efficient strigolactone analogs with simple structure

2017 ◽  
Vol 69 (9) ◽  
pp. 2319-2331 ◽  
Author(s):  
Muhammad Jamil ◽  
Boubacar A Kountche ◽  
Imran Haider ◽  
Xiujie Guo ◽  
Valentine O Ntui ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Simple Structure ◽  
Complex Structure ◽  
Arbuscular Mycorrhizal ◽  
Structural Diversity ◽  
Striga Hermonthica ◽  
Biological Processes ◽  
Structural Modifications ◽  
New Class ◽  
Agricultural Applications

abstract Strigolactones (SLs) are a new class of phytohormones that also act as germination stimulants for root parasitic plants, such as Striga spp., and as branching factors for symbiotic arbuscular mycorrhizal fungi. Sources for natural SLs are very limited. Hence, efficient and simple SL analogs are needed for elucidating SL-related biological processes as well as for agricultural applications. Based on the structure of the non-canonical SL methyl carlactonoate, we developed a new, easy to synthesize series of analogs, termed methyl phenlactonoates (MPs), evaluated their efficacy in exerting different SL functions, and determined their affinity for SL receptors from rice and Striga hermonthica. Most of the MPs showed considerable activity in regulating plant architecture, triggering leaf senescence, and inducing parasitic seed germination. Moreover, some MPs outperformed GR24, a widely used SL analog with a complex structure, in exerting particular SL functions, such as modulating Arabidopsis roots architecture and inhibiting rice tillering. Thus, MPs will help in elucidating the functions of SLs and are promising candidates for agricultural applications. Moreover, MPs demonstrate that slight structural modifications clearly impact the efficiency in exerting particular SL functions, indicating that structural diversity of natural SLs may mirror a functional specificity.

Nonlinear Analysis of Cable Net Structures Suspended from Arches with Block and Tackle Suspension System, Taking into Account the Friction of the Pulleys

2009 ◽  
Vol 24 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Krisztián Hincz
Keyword(s):  
Structural Analysis ◽  
Static Analysis ◽  
Simple Structure ◽  
Complex Structure ◽  
Numerical Procedure ◽  
Suspension System ◽  
Dynamic Relaxation ◽  
Final State ◽  
The Stability ◽  
External Loads

A numerical procedure for the static analysis of arch-supported tensile structures with block and tackle suspension system is presented. The procedure, based on dynamic relaxation, is suitable for a structural analysis both in the prestressing process and in a final state under external loads. The friction between the pulley and its shaft is also taken into account in the analysis. After the introduction of the developed procedure, two structures are presented as examples. The analysis of a very simple structure validates the procedure, then the analysis of a more complex structure, an arch-supported cable net roof illustrates the stability and efficiency of the procedure.

scholarly journals The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs

2009 ◽  
Vol 66 (4) ◽  
pp. 691-698 ◽  
Author(s):  
W. R. Hunter ◽  
M. D. J. Sayer
Keyword(s):  
Habitat Complexity ◽  
Artificial Reef ◽  
Structural Complexity ◽  
Marine Species ◽  
Rocky Reef ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Concrete Blocks ◽  
Belt Transect ◽  
Natural Reefs

Abstract Hunter, W. R., and Sayer, M. D. J. 2009. The comparative effects of habitat complexity on faunal assemblages of northern temperate artificial and natural reefs. – ICES Journal of Marine Science, 66: 691–698. Several north temperate marine species were recorded on subtidal hard-substratum reef sites selected to produce a gradient of structural complexity. The study employed an established scuba-based census method, the belt transect. The three types of reef examined, with a measured gradient of increasing structural complexity, were natural rocky reef, artificial reef constructed of solid concrete blocks, and artificial reef made of concrete blocks with voids. Surveys were undertaken monthly over a calendar year using randomly placed fixed rope transects. For a number of conspicuous species of fish and invertebrates, significant differences were found between the levels of habitat complexity and abundance. Overall abundance for many of the species examined was 2–3 times higher on the complex artificial habitats than on simple artificial or natural reef habitats. The enhanced habitat availability produced by the increased structural complexity delivered through specifically designed artificial reefs may have the potential to augment faunal abundance while promoting species diversity.

The effect of increased ground-level habitat complexity on mouse population dynamics

2003 ◽  
Vol 30 (6) ◽  
pp. 565 ◽  
Author(s):  
A. D. Arthur ◽  
R. P. Pech ◽  
A. Drew ◽  
E. Gifford ◽  
S. Henry ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Native Species ◽  
Habitat Complexity ◽  
Habitat Structure ◽  
Ground Level ◽  
Low Complexity ◽  
Mouse Population ◽  
Introduced Predators ◽  
The Impact

We investigated experimentally the influence of habitat structure on the population dynamics of house mice. Three habitat types were used. In one, dense stands of regenerating cypress pine were felled and left in situ to cover at least 40% of experimental plots, providing high complexity at ground level; in another, dense stands of regenerating pine were left intact, providing low complexity at ground level; in the third, open grassland adjacent to dense stands of regenerating pine also provided low complexity at ground level. Mouse populations occurred at higher densities in felled pine plots compared with both the standing pine and grassland plots, consistent with the hypothesis that the presence of increased habitat complexity at ground level reduced the impact of predation. Even though populations responded to the felled pine, they dropped to very low densities over winter, suggesting that the habitat was still marginal for the persistence of mice, probably due to a lack of food. The results are discussed with reference to their implications for the influence that habitat structure may have on the impact of introduced predators on native species.

scholarly journals Micro-FTIR and EPMA Characterisation of Charoite from Murun Massif (Russia)

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Maria Lacalamita
Keyword(s):  
Single Crystal ◽  
Complex Structure ◽  
Structural Complexity ◽  
Adsorbed Water ◽  
Bending Vibration ◽  
Structural Water ◽  
Stretching Vibration ◽  
Vibrational Features ◽  
Polytype Structure ◽  
Insight Into

Combined micro-Fourier transform infrared (micro-FTIR) and electron probe microanalyses (EPMA) were performed on a single crystal of charoite from Murun Massif (Russia) in order to get a deeper insight into the vibrational features of crystals with complex structure and chemistry. The micro-FTIR study of a single crystal of charoite was collected in the 6000–400 cm−1 at room temperature and after heating at 100°C. The structural complexity of this mineral is reflected by its infrared spectrum. The analysis revealed a prominent absorption in the OH stretching region as a consequence of band overlapping due to a combination of H2O and OH stretching vibrations. Several overtones of the O-H and Si-O stretching vibration bands were observed at about 4440 and 4080 cm−1 such as absorption possibly due to the organic matter at about 3000–2800 cm−1. No significant change due to the loss of adsorbed water was observed in the spectrum obtained after heating. The occurrence of well-resolved water bending vibration bands at about 1595 and 1667 cm−1 accounts for more than one structural water molecule as expected by charoite-90 polytype structure model from literature. The chemical composition of the studied crystal is close to the literature one.

scholarly journals Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions

2020 ◽  
Vol 12 (6) ◽  
pp. 1011 ◽  
Author(s):  
Atsuko Fukunaga ◽  
John H. R. Burns ◽  
Kailey H. Pascoe ◽  
Randall K. Kosaki
Keyword(s):  
Fractal Dimension ◽  
Coral Reefs ◽  
Habitat Structure ◽  
Coral Cover ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Surface Areas ◽  
Abundance And Diversity

Quantifying the three-dimensional (3D) habitat structure of coral reefs is an important aspect of coral reef monitoring, as habitat architecture affects the abundance and diversity of reef organisms. Here, we used photogrammetric techniques to generate 3D reconstructions of coral reefs and examined relationships between benthic cover and various habitat metrics obtained at six different resolutions of raster cells, ranging from 1 to 32 cm. For metrics of 3D structural complexity, fractal dimension, which utilizes information on 3D surface areas obtained at different resolutions, and vector ruggedness measure (VRM) obtained at 1-, 2- or 4-cm resolution correlated well with benthic cover, with a relatively large amount of variability in these metrics being explained by the proportions of corals and crustose coralline algae. Curvature measures were, on the other hand, correlated with branching and mounding coral cover when obtained at 1-cm resolution, but the amount of variability explained by benthic cover was generally very low when obtained at all other resolutions. These results show that either fractal dimension or VRM obtained at 1-, 2- or 4-cm resolution, along with curvature obtained at 1-cm resolution, can effectively capture the 3D habitat structure provided by specific benthic organisms.

An increase in habitat complexity reduces aggression and monopolization of food by zebra fish (Danio rerio)

1998 ◽  
Vol 76 (4) ◽  
pp. 770-772 ◽  
Author(s):  
Seán P Basquill ◽  
James WA Grant
Keyword(s):  
Danio Rerio ◽  
Coefficient Of Variation ◽  
Habitat Complexity ◽  
Structural Complexity ◽  
Zebra Fish ◽  
Resource Monopolization ◽  
Dominant Fish ◽  
The Relationship ◽  
Complex Habitat

We tested the predictions that an increase in the structural complexity of a habitat causes both a decrease in aggression and the monopolization of resources. Groups of three zebra fish (Danio rerio) were allowed to compete for food in a complex habitat with simulated vegetation and in a simple habitat with no vegetation. As predicted, both the levels of aggression by the dominant fish (P = 0.050) and the coefficient of variation of the amount of food eaten within a group (P = 0.020), a measure of food monopolization, were lower in the complex habitat than in the simple one. Fish that chased competitors more frequently ate more food in both habitats, but the relationship was stronger in the simple than in the complex habitat. Our results suggest that aggression is less useful as a mode of competition in habitats with greater structural complexity. Manipulating the structural complexity of the habitat may be a practical way of controlling the intensity of aggression and resource monopolization in groups of animals.

Research on a Model of Reverberation

2013 ◽  
Vol 321-324 ◽  
pp. 1117-1122
Author(s):  
Li Cai Zhang ◽  
Xiao Juan Tong
Keyword(s):  
High Frequency ◽  
Simple Structure ◽  
Complex Structure ◽  
Chebyshev Approximation ◽  
Comb Filter ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Low Pass ◽  
Absorption Characteristics ◽  
Approximation Criterion

Against defects of lacking consideration of air absorption characteristics to the high frequency signal in Schroeder reverberation model, and the more complex structure in Moorer reverberation model, use equiripple Chebyshev approximation criterion to design 4 FIR comb filter with low-pass characteristics and make the FIR filters in parallel, to get a pure parallel reverberation model. This reverberation model considers the absorption characteristics of air to the high-frequency signal, and has a more simple structure.

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