CHANGES IN POPULATION DENSITY IN AREAS WITH DIFFERENT TYPES OF AGRICULTURAL STRUCTURES

Author(s):  
V. Saraykin ◽  
E. Gataulina
2001 ◽  
Vol 34 (2) ◽  
pp. 299-319 ◽  
Author(s):  
Donley T. Studlar

Canada is unusual among advanced industrial democracies in having some provinces which regularly have greater voter turnouts for provincial than for federal elections. Provincial and federal turnouts by province in Canada are analyzed for the 1945-1998 period using multiple regression analysis, both for each set of elections and by comparing differences between the two. Federal turnout has declined over the years but provincial turnout appears to have increased slightly. Although the effects found here largely confirm previous findings about the relative effects of different types of variables found for the Canadian federal level only, several of the political explanations previously supported in cross-national research find less support. Instead, region, population density, months since the last federal or provincial election, and season of the year generally have greater and sometimes more consistent effects. This suggests the need for more studies of turnout in democracies at sub-central levels.


2019 ◽  
pp. 221-225 ◽  
Author(s):  
Zhdanova ◽  
Kryuchkova

The distribution of mites on the soil surface of different types of pastures, the invasion of oribatids by monies larvae are dependent on climatic and weather conditions of the area, as well as the degree of infection with monies of the grazed livestock of ruminants. Seasonal dynamics of population density of oribatid ticks on natural and artificial pastures of two livestock farms of the Ivanovo region is studied. In soil and grass samples 5 species of shell mites were identified: Scheloribates laevigatus, Scheloribates latipes, Punctoribates punctum, Punctoribates sellnicki and Ceratozetes mediocris, cysticercoid-infested monies. Dominant species were representatives of the genus Scheloribates (65,8%), subdominant – genus Punctoribates (26,7%). The population density of oribatid mites on natural grassland pastures in may averaged 198±17,8 specimens per 1 m2 with cysticercoid monies equal to 3,39%. In June-July, the number of oribatids ranged from 249±23,5 – 298±31,2 specimens on 1 m2 at EI = 4,47–6,9% respectively. The greatest number of oribatids was found in August-September: 343±39,4 – 368±42,4 specimens per 1 m2 at EI = 8,7–9,2%. In October the population density of oribatid mites decreased to 201±28,4 individuals per 1 m2 at EI = 4,54%. Artificial (cultural) pastures, the number of oribatid mites does not exceed 108±9,3 individuals per 1 m2. The contamination of the oribatids with cysticercoids of moniesia on these pastures has not been found. The research results make it possible to assume a high degree of invasion of ruminants by moniesia when grazing them on natural meadow pastures and plan preventive measures.


2019 ◽  
Vol 56 (No. 1) ◽  
pp. 30-34
Author(s):  
Petr Zahradník ◽  
Marie Zahradníková

Pityogenes chalcographus (Linnaeus, 1758) is a significant pest of young spruce stands up to the age of about 20 years. Predation can be a significant part of decreasing its population density. The aim of the research was to determine the relationships between captured P. chalcographus and its major predator Nemosoma elongatum (Linnaeus, 1761). The research was conducted in 2006 and 2007 in five areas with the following conditions: two clear-cuts covered with freely distributed brushwood, two clear-cuts which had no brushwood remaining and the last locality was an older (more than two years older) clear-cut with no brushwood. The catches from the pheromone baited traps used to lure P. chalcographus showed a strong positive correlation between P. chalcographus and N. elongatum. Furthermore, comparisons were drawn between the N. elongatum catches from each clear-cut. The differences in the proportions of the predator N. elongatum to the trapped P. chalcographus were identified between the types of clear-cuts with the highest proportion of trapped N. elongatum in the clear-cuts with the brushwood and the lowest proportion in the clear-cuts with the removed brushwood.


2016 ◽  
Vol 6 (2) ◽  
pp. 95 ◽  
Author(s):  
Nur Endah Wahyuningsih ◽  
Mursid Rahardjo ◽  
Taufik Hidayat

In the last three decades, there has been a four fold increase of dengue incidence globally. The control of the disease depends heavily on controlling the vector. Therefore, it is necessary to develop an ecological data of vector to identify the population density of the mosquitoes. One method to study the density and presence of the mosquitoes is through the use of ovitrap. The aim of this research is to identify the effect of two different types of ovitraps. One hundred and eighty ovitrap consist of coconut shell and glass ovitrap were placed in three different subdistricts which was selected based on the Incidence Rate of DHF in the district of Purwokerto City. The container indices and eggs density were compared between two types of ovitrap. Research was conducted using experimental quasy and the data were analyzed with the Mann-Whitney test. The total amount of eggs from coconut shell ovitrap were 9328 of eggs were obtain from 51.33 of ovitrap while the total amount of eggs from glass ovitrap only 1858 of eggs were obtain from 29 ovitrap. Statistical test showed significant difference between the amount of eggs of coconut shell higher than the glass. Mosquitoes prefer natural coconut shell ovitrap compared with artificial ovitrap so we recommended that to eradicate the mosquitoes nest, should not only artificial containers but also natural container to be managed in order to control the dengue vector.


2020 ◽  
Vol 9 (3) ◽  
pp. 137-141
Author(s):  
Yulia G. Suetina

The research of the Pseudevernia furfuracea population was carried out in the Mari El Republic on the territory of the Mari Chodra National Park. The lichen-mossy and cowberry pine forests were studied with different relief positions: uplands and lowlands. The paper discusses the use of two indicators of population density: D₁ is a number of thalli on the tree; D₂ is a number of thalli in the substrate area. The distribution of thalli along the trunk of Pinus sylvestris depends on the characteristics of the stand, characteristics of the tree and the position of the trees in the relief. In a well-lightened lichen-mossy pine forest the distribution of the number of thallus is equal at different exposures, but it is different due to the heights of the trunk. The maximum number of thalli is typical for a height of 0,51 m. The most number of thallus grows at the southern and western expositions in less lightened cowberry pine forests. There is a shift in the height of the number of thallus to a height of 11,5 m. There is a dependence of the upper boundary of the thallus distribution along the trunk on the height of the lamellar bark. The highest upper limit of thallus growth (a height of 4,8 m) is typical for the lowering of the lichen-mossy pine forest, where the lamellar bark rises to a height of 7,2 m. The lower boundary of the thallus settlement depends on microclimatic factors. Among them the decisive factor is light. The smallest lower boundary of a thallus settlement (a height of 0,2 m) is typical for an elevation in a lichen-mossy pine forest. This habitat has the highest population density of P. furfuracea.


2018 ◽  
Vol 2 (2) ◽  
pp. 65-74
Author(s):  
H. BARIMANI VARANDI ◽  
M. KALASHIAN ◽  
H. BARARI ◽  
S. A. REZAEI TALESHI

Varandi HB, Kalashian M, Barari H, Rezaei Taleshi SA. 2018. The diversity of wood-boring beetles caught by different traps in northern forests of Iran. Trop Drylands 2: 65-74. Efficacy of trap types is an important factor for sampling, faunistic survey, evaluation of the population density, seasonal dynamic and monitoring of wood-boring beetles. In the present research, the diversity of Wood-boring beetles (i.e., Buprestidae and Cerambycidae) was studied by using different types of trap (window trap, color pan trap, color sticky trap and Malaise trap) in northern forests of Iran (Mazandaran Province, Iran). Different types of traps employed in five study areas, collected a total of 3120 beetles belonging to 55 species (29 Buprestidae and 26 Cerambycidae). The majority of captured specimens were buprestid beetles (79.87%), while only one-fifth of the specimens were Cerambycidae (20.13%). All of the collected beetle specimens were identified to species's level. One genus (Agrilus spp) and the following five species were the dominant species: Acmaeodera rufoguttata Reitter, Anthaxia hyrcana Kiesenwatter et Kirsch, Anthaxia intermedia Obenberger, Chrysobothris affinis (Fabricius) and Stenoprerus rufus (Linnaeus).


Plant Disease ◽  
2004 ◽  
Vol 88 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Z. Kabir ◽  
R. G. Bhat ◽  
K. V. Subbarao

Polygalacturonic acid (PGA) is an important constituent of Sorensen's NP-10 medium (NP-10) for estimating the population density of Verticillium dahliae in soil. Different types of PGA are available, but not all of them favor the growth of V. dahliae. Unavailability of PGA sodium salt from orange (P-1879) has created an unprecedented problem for the quantification of microscle-rotia (MS) of V. dahliae in soil. The PGA from orange (P-3889) that is now available does not support the growth of V. dahliae. Therefore, experiments were conducted to optimize the use of NP-10 prepared with P-3889 and various concentrations of NaOH. NP-10 with P-3889 amended with eight concentrations of NaOH were compared with NP-10 prepared from PGA sodium salt from orange (P-1879, now discontinued) and citrus (P-3850) along with cellophane and Na-pectate media for recovery of MS from soil and growth of V. dahliae on the media. Seven soils were assayed for MS, and eight isolates of V. dahliae were evaluated for growth and production of MS. Concentrations of NaOH >0.035N and <0.02N in NP-10 with P-3889 reduced mycelial growth, microsclerotial production, and recovery of MS from soils. Similarly, NP-10 with P-3850 alone, cellophane, and Na-pectate media had significantly reduced growth on media and recovery of V. dahliae from soils. The NP-10 with P-3889 and 0.025N NaOH consistently yielded numbers of V. dahliae MS from soil samples and supported the growth and production of MS similar to the NP-10 with P-1879. The medium developed in this study can serve as a direct replacement for the original NP-10 that was developed nearly three decades ago, an important component of which is no longer available.


Sign in / Sign up

Export Citation Format

Share Document