Relations Among Spatiotemporal Heterogeneity, Population Abundance, and Variability in a Desert

1991 ◽  
pp. 202-223 ◽  
Author(s):  
Moshe Shachak ◽  
Sol Brand
Keyword(s):  
Population Abundance ◽  
Spatiotemporal Heterogeneity

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 Spatiotemporal Heterogeneity of Ecological Policy Compromises Human Well-Being and Giant Panda Habitat Conservation in Giant Panda National Park

2021 ◽  
Vol 13 (9) ◽  
pp. 5013
Author(s):  
Dan Zhu ◽  
Degang Yang
Keyword(s):  
Environmental Factors ◽  
Socioeconomic Factors ◽  
National Park ◽  
Structural Equation ◽  
Giant Panda ◽  
Conservation Status ◽  
Well Being ◽  
Habitat Conservation ◽  
Spatiotemporal Heterogeneity ◽  
Panda Habitat

Identifying how policy, socioeconomic factors, and environmental factors influence changes in human well-being (HWB) and conservation efficiency is important for ecological management and sustainable development, especially in the Giant Panda National Park (GPNP). In this study, we systematically analyzed the differences in the conservation status of the giant panda habitat and changes in HWB over 15 years in the GPNP, which includes six mountain sites, Minshan (MS), Qionglai (QLS), Xiaoxiangling (XXL), Liangshan (LS), Qinling (QL), and Daxiangling (DXL). Redundancy analyses were used to determine the factors contributing (policy, socioeconomic factors, and environmental factors) to HWB and giant panda habitat conservation (HC). In addition, using a structural equation model (SEM), we investigated the relationship between the aforementioned three factors and their direct and indirect effects on HWB and HC. The results indicated that there was spatiotemporal heterogeneity of HWB and HC in our study area. There was an increasing number of plant species as well as an increased number of giant panda in GPNP. Generally, HWB in 2015 showed an increasing trend compared with that in 2000. Socioeconomic factors (23.6%) have the biggest influence on HWB and HC, followed by policy (23.2%) and environmental factors (19.4%). Conservation policy had a significantly positive influence on HWB (0.52), while it negatively influenced HC (−0.15). Socioeconomic factors significantly negatively influenced HWB (−0.38). The formulation and implementation of policies to promote economic development will contribute to the protection of giant pandas and their habitat. Our results provide insight on the conservation status of the giant panda habitat, HWB, and factors influencing them in different mountain sites in the GPNP, as well as having implications for the future management of the GPNP.

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 Spatiotemporal Heterogeneity in the Induction of Ventricular Fibrillation by Rapid Pacing

1999 ◽  
Vol 84 (11) ◽  
pp. 1318-1331 ◽  
Author(s):  
Ji-Min Cao ◽  
Zhilin Qu ◽  
Young-Hoon Kim ◽  
Tsu-Juey Wu ◽  
Alan Garfinkel ◽  
...  
Keyword(s):  
Ventricular Fibrillation ◽  
Rapid Pacing ◽  
Spatiotemporal Heterogeneity

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.

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