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1.
Yosiaki It? 《Researches on Population Ecology》1964,6(1):13-21
Summary To elucidate the basic food requirement of spiders, the important polyphagous predators of rice-plant insect pests, an attempt
was made to measure the respiratory energy loss of fasting spiders,Lycosa pseudoannulata.
Relationship between fresh (y) and dry (x) weights of spiders inhabiting the bottom layer of the rice-plant community was represented by the following allometric equation:y=0.428x
0.872.
The carbon dioxide production by previously fed and unfed females under the dark at 29°C 100% R. H. was measured by a titration
technique. The relationship between fresh body weight and CO2 production by unfed animals could be represented by the equationM=aW
b, M being the CO2 output per individual per day andW the fresh body weight. The constantb, which determines the slope of curve, was 0.808. Respiration of the adult female with 100 mg fresh weight was 1.155±0.250
mg CO2/100 g fresh weight/day or 48.69 mg CO2/g dry weight/day. This value corresponds to 35.81 cal/g fresh weight/day or 150.94 cal/g dry weight/day. Supposing the calorific
content of spiders to be 5820 cal/g dry weight, rate of the respiratory energy loss to total energy of the body was estimated
to be 2.60%. This rate did not strongly contradict with the loss of fresh body weight before and after the measurement.
The metabolic rate showed remarkable fluctuation with changing food supply. The CO2 production of starved individuals decreased to 83.63±16.34% as compared with individuals which were fed before the measurement. 相似文献
2.
Summary Let us consider a strip-wise habitat of line-segment, like a corridor, to simplify the subject mathematically, and assume
that the length of the habitat is γ and there aren individuals. Here, we assume that the spatial pattern of the individuals is random if then distances from the left end of the habitat to each individual follow a uniform distribution on the strip. Under such an assumption,
the variance of the distances between any two neighbors is represented by the formulanθ
2(n+1)−2(n+2)−1 and the variance betweenn+1 distances betweenn individuals from the left end to the right end to the strip, is represented by the formulanθ
2(n+1)−2(n+2)−1. These two kinds of variances can be used for determining (1) the spatial pattern of a population on the strip and (2) the
spatial structure within the population, by comparison with the variances calculated from the data. Two examples cited from
the literature, a cattle population on a pasture and an aphid population on a sycamore leaf, are presented. 相似文献
3.
JACQUES DEMONGEOT 《Mathematical Population Studies》2013,20(4):199-209
ABSTRACT For a unimodal growth function f having its maximum at a critical state x c , the interval bounding the population size asymptotically is usually presented as being equal to [f ○2(x c ), f(x c )]. This interval however does not represent the maximum range within which the population size can vary, even asymptotically. The actual invariant interval containing the population size is equal to: [min(x*, f ○2(x c )), f(x c )], where x* denotes the non-zero fixed point, assumed to be unique, of the iteration of f. 相似文献
4.
Measurement of non-randomness in spatial distributions 总被引:4,自引:0,他引:4
Roger H. Green 《Researches on Population Ecology》1966,8(1):1-7
Summary The measurement of departure from randomness in spatial distributions has widespread application in ecological work. Several
“indices of non-randomness” are compared with regard to their dependence on sample number, sample size and density. Criteria
for the best choice of index for specific situations are discussed. A new coefficientC
x is proposed for use with positively contagious distributions and tests of significance are given. WhenC
x and another index (S
2/m−1) are used for positive and negative contagion respectively, values ranging from −1 through 0 (random) to +1 are obtained,
regardless of sample number, sample size or density. 相似文献
5.
Summary Effects of starvation on the suryival period and the respiratory rate in adults of a wolf spider,Pardosa astrigera (L. Koch), were investigated. The spiders used were divided into four groups: well-fed, starved and two limited food groups; in the
latter two, each spider was supplied with one leafhopper every second or third day. Adult males and females ofP. astrigera could survive for a long time; 28.8±2.7 days and 54.4±18.9 days, respectively, without any food. The longevities shown here
were 73.8% for males and 78.6% for females of those of well-fed spiders, indicating thatP. astrigera adults have a strong tolerance to starvation. The respiratory rate of well-fed adults showed no tendency to increase or decrease
with their aging; the mean respiratory rates were 4.86×10−4 mg CO2/mg f.w. (fresh body weight)/hr for males and 3.80×10−4 mg CO2/mg f.w./hr for females. The respiratory rates of starved spiders increased during the first two days of starvation but decreased
markedly from the third to the twelfth day, and thereafter retained an almost constant level for each sex. The mean respiratory
rates after the twelfth day of starvation were 2.49×10−4 mg CO2/mg f.w./hr for males and 2.76×10−4 mg CO2/mg f.w./hr for females; these values were respectively 48.4% and 63.0% of those prior to starvation. The fresh body weight
of starved spiders decreased linearly with time but the rate was small. The respiratory rates of the limited food groups tended
to decline with time and thereby their weight losses were minimized. The decrease in the respiratory rate under starvation
was considered not to be due to spider exhaustion or senescence but due to an intrinsic change in behaviour and/or metabolism,
because when the spiders were supplied with ample food for five days after starvation, the respiratory rate and the body weight
rapidly recovered to near the levels prior to starvation. It is suggested that starved spiders use a higher ratio of fat as
catabolic substrate than normally fed or satiated ones. Feeding strategies of poikilo-therm predators are discussed.
This work was partially supported by the Nippon Life Insurance Foundation Research Fund and Grant-in-Aid (No. 56480039) from
the Ministry of Education, Science and Culture, Japan. 相似文献
6.
Xian Liu Charles C. Engel David W. Armstrong Han Kang 《Population research and policy review》2008,27(3):293-306
In this paper, we present and develop the argument that if the survival functions for two population subgroups converge in
later life, a mortality crossover must precede the occurrence of this convergence. Specifically, two survival curves, S
1(x) and S
2(x), associated with two distinct population subgroups, G1 and G2, tend to converge before all members die out, as often observed and anticipated. This convergence leads to an increased mortality
acceleration for the “advantaged” group, and eventually fosters the occurrence of a mortality crossover. We present a mathematical
proof for this relationship and offer several explanations for the mechanisms involved in the process of survival convergence
and the preceding mortality crossover. This new presentation demonstrates that mortality crossover is a highly observable
demographic event given the trend of survival convergence in later life. 相似文献
7.
Minoru Murai 《Researches on Population Ecology》1975,16(2):289-308
Summary A model was made to clarify the basic processes of competition to occur among larvae by the exploitation as defined byBakker (1969). It was found that this model is applicable to the experimental results on the food exploitation amongDroshophila larvae obtained byBakker (1961). In the model the preimaginal stage is divided into two periods;T
f
which is the time that a group of larvae spends in exhausting the food after hatching, andT
s
which is the duration of the starvation period afterT
f
.T
f
and thenW
l
(larval body weight) just after the end ofT
f
are decided byF
s
(amount of food supplied per larva at larval hatching) andF
c
(amount of food consumed per larva).T
f
affects on the onset ofT
s
as well asR
l
(rate of decrease in the individual body weight duringT
s
).W
a
(weight of emerging adults) is gotten by a subtraction ofR
l
fromW
l
just after the end ofT
f
,R
e
is affected directly by these components ofW
l
andR
l
. As a result,W
a
andR
e
are expressed by functions ofF
s
. This model confirmed that the food exploitation lead to the competition of scramble type. Finally it was suggested that
there exist some strategies which prevent ill-effects owing to the food exploitation. 相似文献
8.
Takaya Ikemoto 《Researches on Population Ecology》1978,19(2):237-249
Summary The spatial distribution patterns of the population ofAnopheles sinensis larvae were studied in the rice field area in the suburb of Urawa city in Japan, during the summer seasons in 1973 and 1974.
The distribution pattern of the larval population within the field, analysed by the m−m regression method, indicated that
the basic component of larval distribution was not a group of individuals but a single individual and such components were
distributed contagiously over the field. This basic pattern did not change significantly according to developmental stage,
census date or field. Therefore, we could describe the distribution pattern of the population in a rice field by the single
linear regression, x=0.021+1.339x(r2−0.912).
Also, the relation for the whole population in the field area including the five fields could be shown by the linear regression,
x=0.049+1.749x(r2−0.959). The value of α remained to be nearly equal to zero, but the value of β became larger than the value for the single-field
relation. Such a change in distribution pattern seemed to reflect the greater heterogeneity in conditions among the fields
than within individual field.
Using the information on the distribution patterns mentioned above, some considerations were given on the sampling plans for
mosquito larvae, including samplesize determination and application of sequential methods to estimate population size as well
as to classify population level. 相似文献
9.
Summary The population dynamics of an epilachnine beetle, which is closely related toEpilachna sparsa
Dieke (henceforth called “sp. C”) and feeds on bitter cucumberMomordica charantia, was studied by mark-recapture of adults and the construction of life tables. The study was repeated three times, i.e., March–May,
July–September and October–December in 1982, in Padang, Sumatra, Indonesia. After the establishment of the host plants, adults
of “sp. C” soon colonized, and each study period ended in the death of the plants due to defoliation by the larvae and adults.
The estimated mean length of residence of adults ranged from 6–11 days, but this was probably much shorter than the actual
longevity, because the adults were so active that they flew away, or dropped off the plants, when they were approached or
slightly disturbed. Life tables indicated that egg mortality ranged from 17.8–53.9%, and a parasitic waspTetrastichus sp. B made up 41.1–64.2% of egg mortality. Two wasps,Tetrastichus sp. C andPediobius foveolatus killed 1.2–19.4% (7.6–100%)* of 4th instars and only the latter species attacked the pupae, killing 24.6–59.1% (45.1–72.4%). Parasitism and starvation
by overcrowding contributed most to the total mortality from egg to adult emergence, which ranged from 89.4–99.5%. “Sp. C”
had a higher diversity and level of parasitism than the Japanese species,E. vigintioctopunctata. The high dispersal power of “sp. C”, coupled with the prolongedl
x−mx schedules shown under laboratory conditions, was advantageous for exploiting the food plant which was available throughout
the year, but was rather patchily distributed in space. 相似文献
10.
Evaluation of statistical precision and design of efficient sampling for the population estimation based on frequency of occurrence 总被引:1,自引:0,他引:1
Eizi Kuno 《Researches on Population Ecology》1986,28(2):305-319
Summary The binomial sampling to estimate population density of an organism based simply upon the frequency of its occurrence among
sampled quadrats is a labour-saving technique which is potentially useful for small animals like insects and has actually
been applied occasionally to studies of their populations. The present study provides a theoretical basis for this convenient
technique, which makes it statistically reliable and tolerable for consistent use in intensive as well as preliminary population
censuses. Firs, the magnitude of sampling error in relation to sample size is formulated mathematically for the estimate to
be obtained by this indirect method of census, using either of the two popular models relating frequency of occurrence (p) to mean density (m), i.e. the negative binomial model,p=1−(1+m/k)
−k, and the empirical model,p=1−exp(−am
b). Then, the equations to calculate sample size and census cost that are necessary to attain a given desired level of precision
in the estimation are derived for both models. A notable feature of the relationship of necessary sample size (or census cost)
to mean density in the frequency method, in constrast to that in the ordinary census, is that it shows a concave curve which
tends to rise sharply not only towards lower but also towards higher levels of density. These theoretical results make it
also possible to design sequential estimation procedures based on this convenient census technique, which may enable us with
the least necessary cost to get a series of population estimates with the desired precision level. Examples are presented
to explain how to apply these programs to acutal censuses in the field. 相似文献
11.
Kazuo Nakamura 《Researches on Population Ecology》1982,24(2):302-317
Summary The prey capture tactics of spiders was analyzed, considering the energy gained by the capture of prey and that required for
it. For the purpose of it, a growth model of spiders was constructed, expressing the flow rate of prey biomass to the spider's
body by differential equations. Solving these equations under the differing values of three parameters, growth curves of spiders
was obtained. These three parameters are the amount of prey biomass supplied daily to spiders,x
0, the rate of prey capture of spiders, α, and a coefficient of the respiration rate required for the capture of prey,k. When the value ofk increased, spiders could grow only at high value ofx
0. These results suggest that habitats with small prey biomass are preferred by spiders adopting a sit-and-wait tactics for
prey capture, which requires small values ofk. Wolf spiders are one of these spiders showing that tactics. On the other hand, web-builders which require large amount of
energy for spinning webs (namely, take large value ofk), are able to grow only in the habitats with large prey biomass. Each species of spiders are considered to locate in a certain
point between both extremes of these tactics for the capture of prey. 相似文献
12.
Syun'iti Iwao 《Researches on Population Ecology》1977,18(2):243-260
Summary and Conclusion The measurement of spatial association between two species is considered on the basis of interspecies mean crowding. Two indices
of overlapping, γ andC
p, are derived as geometric and weighted arithmetic means of the same component ratios related to inter-and intraspecies mean
crowdings. Both indices behave in a similar way, ranging from 1 when the distributions of two species are completely overlapped
to 0 when they are completely exclusive with each other. The former is essentially identical with indices proposed byKuno (1968) andPianka (1973), and the latter is a modified form ofMorisita's (1959)C
σ index. Indices to measure the degree of spatial correlation between species, Ω andR
μ, are then derived for both kinds of overlapping indices, which vary from 1 in complete overlapping, through 0 in independent
occurrence, to −1 in complete exclusion.
Various kinds of interspecies association are analyzed using these indices and an extended form of the
regression graph which provides a convenient way of indicating the spatial interrelation between two species as well as distribution
patterns of respective species.
The method presented in this paper may also be applicable to compare temporal distribution patterns between species, similarity
between communities, etc. For such a wider application which includes continuous as well as discrete distributions, the interpretation
of intra-and interspecies mean crowdings is not necessarily appropriate, and hence the concept of mean concentration with
the symbols
and
for intraspecies relation and
and
for interspecies relation is suggested.
This study was supported by Science Research Fund (No. 148041) from the Ministry of Education. 相似文献
13.
Tock H. Chua 《Researches on Population Ecology》1992,34(2):285-292
Summary The effect of body size, as measured by the head width, of the femaleBactrocera sp. Malaysian A (kept separately in sexual pairs) on the demographic parameters was investigated in the laboratory under
ambient conditions of 28–30°C, 78–85% RH and natural photoperiod. Body size was shown to influence significantly all the demographic
parameters. The expectation of life of females at eclosion from pupae was respectively for head widths of 1.6, 1.8, 1.9, 2.0
and 2.1 mm: 76.2, 73.4, 73.8, 102.4 and 115.2 days. The mean number of eggs laid per female in its life time was respectively:
86.4±48.7, 181.8±56.1, 229.7±72.6, 364.3±69.4 and 477.5±109.3 which was significantly different from one another (F=3.73,P<0.05) especially the two smaller sizes from the two larger sizes. The regression line for total eggs laid (Y) against head width (X) wasY=785.2X−1208.7 (R
2=0.35,P<0.001). The net reproductive rate (R
0) was respectively 15.8, 34.0, 43.5, 66.9 and 88.8 eggs, while the intrinsic rate of increase (r) was respectivley 0.0435, 0.0538, 0.0670, 0.0665 and 0.0711. The results confirm that for mass rearing purposes, larger females
which produce more offspring are to be preferred. 相似文献
14.
Masahiro Nakaoka 《Researches on Population Ecology》1993,35(2):199-213
Summary Long-term variation in recruitment was estimated by constructing projection matrices for a marine bivalve,Yoldia notabilis, at two stations in Otsuchi Bay, northeastern Japan, and the effects of its variation on population dynamics were examined
using a simple matrix model. The matrix model was developed from the Leslie matrix, in which the population growth rate λ
was expressed as a function of recruitment rater
0. The equilibrium recruitment rater
s, or the recruitment rate required to maintain population at constant size (λ=1), was expressed by the reciprocal of the reproductive
value of a newly recruited individual. The estimates ofr
s for the field population were lower at the shallower station than at the deeper station, reflecting higher survivorship and
fecundity. Past recruitment rate estimated both by the field samplings for 3 years and by the back-calculation from the current
age structure for over 10 years showed large yearly variation, ranging between 0 and 58.6×10−4. The estimates were larger thanr
s, and hence, large enough to increase population size (λ>1) only in approximately one-third of the estimated years. This suggests
that the population has been maintained by occasional successful recruitment occurring once every few years. 相似文献
15.
Summary Larval growth patterns ofHemipyrellia ligurriens (Calliphoridae) andBoettcherisca formosensis (Sacophagidae) in crowded and uncrowded cultures were compared. Growth of the larvae followed a sigmoid curve. The highest
larval growth rates were 0.33 and 0.36 mg h−1 for uncrowded and crowdedH. ligurriens respectively. The corresponding figures were 2.38 and 1.23 mg h−1 forB. formosensis. Larvae of both species attained maximum weight earlier in crowded cultures than in uncrowded cultures, although the final
weights attained in crowded cultures were less. The earlier period of most rapid growth in both species was interpreted as
a result of intraspecific facilitation at higher larval densities. UncrowdedB. formosensis had a shorter larval to pupal development and an earlier period of most rapid growth than uncrowdedH. ligurriens, suggesting the former may be superior in exploiting carcasses with limiting food. 相似文献
16.
Summary Suppose thatn individuals locate independently and randomly on a segment of line of finite length (habitat). Let the theoretical and observed
ranges of the sites of the individuals on the segment be μ
n-1 andr
n-1, respectively. Then, the degree of dispersion of the individual sites is measured by the ratio, T
n
=n
n-1/μ
n-1, as follows: A random spatial pattern forI
r−1
=1 An aggregated spatial pattern for 0≤I
r
<1 A uniform spatial pattern for (n+1)/(n−1)≥I
r
>1.
Another method was derived. Let the probability that an observed range is less thanr
n−1
beI
p
, under the hypothesis of a Beta distribution. Then
indicates A random spatial pattern forI
p
=1/2 An aggregated spatial pattern forI
p
<1/2 A uniform spatial pattern forI
p
>1/2.
The first index can be used for comparing populations having the same number of individuals, whereas the second one can be
used for comparing populations with different numbers of individuals. 相似文献
17.
Summary Modelling studies are presented which describe the effect of lek mating on the control of a wild population by sterile male
release. The mixed leks are assumed to follow a Poisson-binomial distribution and the system includes three parts: territory
defense, matings inside a lek and matings outside a lek. The effects of parameters on the hatchability are discussed. Among
the parameters, sterile type effect (W
s
), female choice (f
s
) and mating competitiveness (C
m
) are the most important. The application to determining the effects of sterile male release and on the proportion of sterile
males required for eradication are also discussed. 相似文献
18.
Tiffany L. Cox Christie Zunker Brooks Wingo Dana-Marie Thomas Jamy D. Ard 《Social indicators research》2010,99(3):531-540
African American (AA) women’s preference for a larger body size and underestimation of their body weight may affect the relationship
between their body weight and weight-related quality of life (QOL). We wanted to examine the relationship between weight-related
QOL and body mass index (BMI) in a sample of overweight AA women. Thirty-three overweight AA women completed a clinic visit
to measure height, weight, and complete surveys including the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) and the
Stunkard Figure Rating Scale. BMI was calculated using measured height and weight. Correlations and linear regression models
were estimated using SAS v 9.1. In this sample, the mean total quality of life score was 78.00 ± 17.68 on a 100 point scale.
There was a modest correlation between BMI and total weight-related QOL (r = −0.034, p = 0.053). Body image dissatisfaction was the strongest predictor of total quality of life score (p = 0.04). African American women’s unique cultural perception of body image may play a key role in weight-related QOL. 相似文献
19.
Paul A. Murtaugh 《Journal of Population Research》2010,27(2):63-73
I develop probabilistic interpretations for the United Nations’ 10-year population forecasts by comparing 1995 projections
for 212 countries to the population sizes reported for 2005. Errors in the estimation of the intrinsic rate of increase, presumably
caused by erroneous assumptions about birth, death and/or immigration rates, appear to be more consequential than errors based
on inaccurate estimation of the starting, or ‘jump-off’, population size. For only about 20% of the countries did the ‘actual’
2005 population size fall between the United Nations’ low- and high-variant projections. I propose prediction intervals for
country-specific population sizes 10 years in the future of the form [ Ni¢ (t+10) / k , k ·Ni¢ (t+10) ],[ N_i^{\prime} (t+10) / k , \, k \cdot N_i^{\prime} (t+10) ], where N
i
′(t + 10) is the medium-variant prediction for year t + 10 made in year t, and k is a number that varies with starting population size. Based on the 1995–2005 United Nations’ data, values of k giving 95% coverage range from 1.11 for countries with a population on the order of 109, to 1.45 for countries with a population of 105. 相似文献
20.
The availability and safety of drinking water and the environmental quality of life was investigated in five cities located
in an oil-producing area of Nigeria using questionnaire-based scales, discussion and laboratory tests. Polythene-packaged
sachet water and commercial and non-commercial private boreholes largely met the drinking water requirement of the cities.
Consumption of sachet water was high (14.0–20.0 points vs. 25.0 points) but regression analysis indicated strong negative
relationships with income group (β = −0.75, P < 0.005) and educational level (β = −0.77, P < 0.005) of respondents (658). Private borehole water was prevalent (18.7–19.9 vs. 20.0) while public water supplies were
almost non-existent (4.8–5.6 vs. 20.0) in the cities. Vulnerability to contamination in all water sources was indicated following
unacceptable counts of total and faecal coliform bacteria in 10–62.5 and 3–25% of samples, respectfully. Respondents were
not satisfied with environmental quality of life indicated by the quality of housing, school, health services, refuse disposal,
recreation, streetlight, transport and police (3.43–4.01 vs. 10). It is concluded that modernization and industrialization
due to the oil and gas industries, tended to increase individualization to the negligence of common services as evidenced
by the preponderance of private boreholes and sachet water. 相似文献