Population abundance gradient of Inurois punctigera along altitude

2019 ◽  
Vol 23 (1) ◽  
pp. 23-27
Author(s):  
Satoshi Yamamoto ◽  
Seiko Matsuhisa
Keyword(s):  
Population Abundance ◽  
Abundance Gradient

KELIMPAHAN POPULASI DAN PERBEDAAN MORFOMETRI Telescopium telescopium PADA HABITAT MANGROVE DI SUNGAI BONGKOK KAMPUNG BAGAN TANJUNG PIAYU DAN DI SEKITAR TPA PUNGGUR KOTA BATAM

SIMBIOSA ◽  
2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Yarsi Efendi ◽  
Ramses Ramses ◽  
Adil Waraney
Keyword(s):  
Random Sampling ◽  
Research Result ◽  
Sampling Point ◽  
Population Abundance ◽  
Mangrove Habitat ◽  
Measurement Result ◽  
Garbage Disposal

The Research have done started from February to June 2013, have purpose to compare the population abudance and difference of morphometric Telescopium telescopium in two different observation places. The sampling point determined by method of random sampling. The sample has taken by plot measurement 10x10 m and the sub plot measurement 1x1 m placed in 5 pieces plot measurement 10x10 m.The research result got 62 individual Telescopium telescopium in research location with the density value 0.155 (ind/m²) at 1st location and 297 individual Telescopium telescopium with the density value 0.7425 (ind/m²) at 2nd location. The average measurement result (length and dimeter) morphometric of Telescopium telescopium found at mangrove habitat in Sungai Bongkok was length 8.94 cm and diameter 4.73 cm. The morphometric average measurement result (length and diameter) Telescopium telescopium found at mangrove habitat around the garbage disposal Punggur was length 4.66 cm and diameter 2.54 cm. Keywords: Population Abundance; Morphometric; Telescopium telescopium. 

scholarly journals Population abundance, natural history, and habitat use by the arboreal marsupialDromiciops gliroidesin rural Chiloé Island, Chile

2012 ◽  
Vol 93 (1) ◽  
pp. 134-148 ◽  
Author(s):  
Juan L. Celis-Diez ◽  
Jennifer Hetz ◽  
Paula A. Marín-Vial ◽  
Gonzalo Fuster ◽  
Pablo Necochea ◽  
...  
Keyword(s):  
Natural History ◽  
Habitat Use ◽  
Population Abundance

scholarly journals Evidence for azimuthal variations of the oxygen-abundance gradient tracing the spiral structure of the galaxy HCG 91c

2017 ◽  
Vol 601 ◽  
pp. A61 ◽  
Author(s):  
F. P. A. Vogt ◽  
E. Pérez ◽  
M. A. Dopita ◽  
L. Verdes-Montenegro ◽  
S. Borthakur
Keyword(s):  
Spiral Structure ◽  
Oxygen Abundance ◽  
Abundance Gradient ◽  
The Galaxy

Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient

1985 ◽  
Vol 42 (5) ◽  
pp. 989-998 ◽  
Author(s):  
G. H. Winters ◽  
J. P. Wheeler
Keyword(s):  
Stock Assessment ◽  
Population Decline ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Population Abundance ◽  
Commercial Catch ◽  
Standard Manner ◽  
Clupea Harengus Harengus ◽  
The Relationship ◽  
Stock Abundance

The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proportional to A, we establish the empirical basis of this relationship through comparisons of q and A of various Northwest Atlantic herring (Clupea harengus harengus) stocks and, in more detail, for Fortune Bay herring. For these stocks the relationship was of the form q = cA−b. For Atlantic herring stocks, levels of b were in excess of 0.80. In Fortune Bay herring, reductions in abundance were accompanied by proportional reductions in A, which in turn was inversely correlated with changes in q. School size, measured as catch per set, also declined as population levels declined but the change was not proportional. Published findings indicate that pelagic stocks in particular, and fish stocks in general, exhibit a common response of reductions in A with interactive increases in the q during periods of rapid population decline. We conclude that the conventional assumption of a constant stock area is usually violated due to the systematic interaction between A and population abundance which is reflected in an inverse relationship between stock abundance and q. Calibration of sequential population models should therefore be restricted to research vessel data collected in a standard manner and covering the distributional area of the stock.

scholarly journals Caution Is Needed When Using Niche Models to Infer Changes in Species Abundance: The Case of Two Sympatric Raptor Populations

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2020
Author(s):  
Adrián Regos ◽  
Luis Tapia ◽  
Alberto Gil-Carrera ◽  
Jesús Domínguez
Keyword(s):  
Habitat Suitability ◽  
Species Abundance ◽  
Peat Bogs ◽  
Population Abundance ◽  
Ecological Niche Models ◽  
Landsat Images ◽  
Sympatric Populations ◽  
Circus Pygargus ◽  
Hen Harrier ◽  
Niche Models

Despite the mounting evidence supporting positive relationships between species abundance and habitat suitability, the capacity of ecological niche models (ENMs) to capture variations in population abundance remains largely unexplored. This study focuses on sympatric populations of hen harrier (Circus cyaneus) and Montagu’s harrier (Circus pygargus), surveyed in 1997 and 2017 in an upland moor area in northwestern Spain. The ENMs performed very well for both species (with area under the ROC curve and true skill statistic values of up to 0.9 and 0.75). The presence of both species was mainly correlated with heathlands, although the normalized difference water index derived from Landsat images was the most important for hen harrier, indicating a greater preference of this species for wet heaths and peat bogs. The findings showed that ENM-derived habitat suitability was significantly correlated with the species abundance, thus reinforcing the use of ENMs as a proxy for species abundance. However, the temporal variation in species abundance was not significantly explained by changes in habitat suitability predicted by the ENMs, indicating the need for caution when using these types of models to infer changes in population abundance.

scholarly journals The time evolution of the Milky Way’s oxygen abundance gradient

2018 ◽  
Author(s):  
M Mollá ◽  
Á I Díaz ◽  
O Cavichia ◽  
B K Gibson ◽  
W J Maciel ◽  
...  
Keyword(s):  
Time Evolution ◽  
Oxygen Abundance ◽  
Abundance Gradient

scholarly journals Bioefficacy of different insecticides against blister beetle Mylabris phalerata (Pallas) on pigeonpea

2017 ◽  
Vol 15 (1) ◽  
pp. 55-65
Author(s):  
AK Singh
Keyword(s):  
Short Duration ◽  
Untreated Control ◽  
Yield Loss ◽  
Population Abundance ◽  
Neem Oil ◽  
Net Return ◽  
Maximum Productivity ◽  
Lambda Cyhalothrin ◽  
And Control ◽  
Blister Beetle

The experiment was accomplished to evaluate the bioefficacy of different insecticides against Mylabris phalerata (Pallas) on pigeonpea. The experiment consisted of seven treatments viz., bifenthrin 62 g a.i. ha-1, lambda-cyhalothrin 24 g a.i. ha-1 (encapsulated with polymers; Matadore), chlorpyriphos 310 g a.i. ha-1+ cypermethrin 31 g a.i. ha-1, cypermethrin 62 g a.i. ha-1, neem oil 1500 ppm, permethrin 154 g a.i. ha-1, chloropyriphos 173 g a.i. ha-1 compared with untreated (control). The sixth day after each spray, minimum population abundance of M. phalerata and maximum percent efficacy in reducing their population was obtained from bifenthrin which was at par with lambda-cyhalothrin, cypermethrin, chlorpyriphos+ cypermethrin and permethrin and all these were significantly effective over chloropyriphos, neem oil and control plots. On the tenth day after each spray, minimum population abundance and highest per cent efficacy were obtained from bifenthrin which was at par with lambda-cyhalothrin and both these treatments were significantly superior over rest of the treatments. The maximum productivity was observed with bifenthrin, while highest net return per rupee investment was obtained from lambda-cyhalothrin treatment. The results explicitly show that out of all treatments, Lambda-cyhalothrin was effective and imposing lucrative against M. phalerata and thereby minimized the yield loss. Three sprays of lambda-cyhalothrin and bifenthrin with an interchange at ten days interval will be effectual and lucrative against M. phalerata in short duration pigeonpea crop.SAARC J. Agri., 15(1): 55-65 (2017)

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