On the action of population density in the population fluctuation of the flour moth,Ephestia cautella

1953 ◽  
Vol 2 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Fumiki Takahashi
Keyword(s):  
Population Density ◽  
Population Fluctuation ◽  
Ephestia Cautella

How soil abiotic factors affect the population fluctuation of Leitneria pugio (Acari: Mesostigmata: Halolaelapidae)

2021 ◽  
Author(s):  
Sahebeh Ghasemi-Moghadam ◽  
Ali Ahadiyat ◽  
Yaghoub Fathipour ◽  
Alireza Saboori
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Distribution Pattern ◽  
Abiotic Factors ◽  
Pearson Correlation ◽  
Negative Relationship ◽  
Predatory Mite ◽  
Spatial Distribution Pattern ◽  
Population Fluctuation ◽  
And Control

Abiotic factors, such as temperature, humidity, soil elements, along with biotic factors affect terrestrial arthropod communities. Since the application of agricultural fertilizers with the entrance of different elements causes changes in the soil physicochemical conditions, fertilizers may cause fluctuation in the population density of edaphic arthropods. Given this opinion, in this research, the effect of common fertilizers on the population fluctuation and distribution pattern of the predatory mite Leitneria pugio (Karg) was investigated. The experimental treatments were granular urea fertilizer with two doses (200 and 400 kg per ha), poultry manure, zinc sludge (to simulate the accumulation of zinc sulfate fertilizer in the soil), and control in five blocks. Humidity, pH, temperature, NO3– and NO2–, and elements (organic Carbon, K, Na, P, Fe, Cu, Pb, Cr, Cd, Ni, Zn, and As) of soil were measured, and their relationship with the predatory mite population was determined by Pearson correlation coefficient. Iwao's patchiness, Taylor's power law, and Morisita's coefficient of dispersion were used for determining the spatial distribution pattern of L. pugio. The spatial pattern of L. pugio was aggregated, and the highest population density of the predator was observed in December in zinc sludge and control treatments, and in May, in zinc sludge treatment, on the average 60, 35, and 110 per m2, respectively. The relationship between mite's population and Cu and Pb was significantly positive, and L. pugio had a significantly negative relationship with P, NO3– and soil temperature. Nevertheless, the application of different fertilizers did not affect the spatial distribution pattern of the predator.

Convergence of regional population density in Russia over 120 years

2020 ◽  
pp. 133-158
Author(s):  
K. A. Kholodilin ◽  
Y. I. Yanzhimaeva
Keyword(s):  
Population Density ◽  
Spatial Dependence ◽  
Population Distribution ◽  
Regional Level ◽  
Capital City ◽  
County Level ◽  
Spatial Effects ◽  
Russian Regions ◽  
Regional Population ◽  
Regional Population Density

A relative uniformity of population distribution on the territory of the country is of importance from socio-economic and strategic perspectives. It is especially important in the case of Russia with its densely populated West and underpopulated East. This paper considers changes in population density in Russian regions, which occurred between 1897 and 2017. It explores whether there was convergence in population density and what factors influenced it. For this purpose, it uses the data both at county and regional levels, which are brought to common borders for comparability purposes. Further, the models of unconditional and conditional β-convergence are estimated, taking into account the spatial dependence. The paper concludes that the population density equalization took place in 1897-2017 at the county level and in 1926—1970 at the regional level. In addition, the population density increase is shown to be influenced not only by spatial effects, but also by political and geographical factors such as climate, number of GULAG camps, and the distance from the capital city.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

Community based design approach as initial stage to promote urban composting from a Hill Station of the Philippines

2019 ◽  
Author(s):  
Marcelino Jr Lunag ◽  
Jessie C. Elauria ◽  
Juanito D. Burguillos
Keyword(s):  
Population Density ◽  
Community Involvement ◽  
The Philippines ◽  
Design Stage ◽  
High Population Density ◽  
Community Based ◽  
Hill Station ◽  
Initial Stage ◽  
Household Members ◽  
Community Based Design

This study confirms that lack of space due to high population density restricts household members and the barangay to comply with the existing law regarding composting. With these, community involvement in the design stage of compost bin as initial stage was done accordingly. The participants were voluntarily interviewed and were given questionnaires, which was endorsed and approved by barangay committee.

Integrated Assessment of Socio-Economic Development of Rural Areas, Taking into Account Differences in Population Density

2020 ◽  
pp. 76-83
Author(s):  
N.N. Balashova ◽  
◽  
D.A. Korobeynikov ◽  
S.A. Popova ◽  
◽  
...  
Keyword(s):  
Sustainable Development ◽  
Economic Development ◽  
Population Density ◽  
Rural Areas ◽  
Rural Population ◽  
Integrated Assessment ◽  
Russian Regions ◽  
Socio Economic Development

Typologization of rural areas, taking into account differences in population density and level of socio-economic development, is necessary to identify “growth points” and strategic sustainability benchmarks. The method of integrated assessment of the level of socio-economic development of rural territories is proposed, according to which the grouping of Russian regions is carried out. Applying data on rural population density to the results of calculations allowed us to identify 12 typological groups, in the context of which unified recommendations on sustainable development of territories should be formed.

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