scholarly journals Structure of young growth of pine in various ecotopes of the Trans-Urals region

2021 ◽  
pp. 53-64
Author(s):  
М.В. Ермакова
Keyword(s):  
Growth Rate ◽  
Age Structure ◽  
Main Part ◽  
Polynomial Equation ◽  
Pine Forest ◽  
Relative Height ◽  
Placement Type ◽  
Two Sides ◽  
Young Growth

Рассмотрены результаты исследования пространственной и возрастной структуры подроста сосны на гарях-вырубках и вырубках сосняка брусничникового Среднего Урала. Показано, что подрост сосны на гарях-вырубках, по сравнению с вырубками, отличается значительно меньшей величиной диаметра на середине высоты ствола, но отличается существенно более высокими темпами роста в высоту. Относительная высота у подроста на гарях-вырубках на 31,5–37,3% выше, чем у подроста на вырубках. Связано это со значительно более высокой густотой подроста на гарях-вырубках, по сравнению с вырубками. Установлено, что большая часть возобновления сосны как на гарях-вырубках, так и на вырубках, была сосредоточена в районах примыкания трех сторон леса. С уменьшением источников обсеменения (примыкание двух сторон леса) густота подроста заметно снижалась. В свою очередь, на открытых участках на гарях-вырубках и вырубках численность подроста была наименьшей. Подрост сосны отличается регулярным (случайным) с переходом к рассеянному (равномерному) типом размещения на гарях-вырубках. На вырубках основной тип размещения – групповой. На гарях-вырубках основная часть деревьев относилась к возобновлению, появившемуся на 2–3-й год после пожаров и последующей вырубки. Возобновление, появившееся как на следующий год, так и на 4–5-й год после удаления древостоя, было незначительным. На 6-й год после пожара и вырубки возобновление полностью прекратилось. На вырубках основная часть деревьев относилась к возобновлению, появившемуся на 4–5-й год после вырубки. Однако, хотя и в значительно меньшей степени, возобновление сосны на вырубках имело место и в последующие годы. Закономерность изменения возрастной структуры подроста для гарей-вырубок хорошо аппроксимируется полиномиальным уравнением 4-го порядка, а на вырубках – 5-го порядка. The results of study of spatial and age structure of pine on slash-cutover and cutover of young growth of pine of cowberry-shrub pine forest of the Trans-Urals region are considered. It has been shown that the undergrowth of pine on slash-cutover in comparison with cutting differs by a significantly smaller diameter at the middle of the trunk height, but differs by a significantly higher growth rate in height. The relative height of the undergrowth on the slash-cutover was 31.5–37.3% higher than that of the undergrowth on the cutover. This is due to the significantly higher density of undergrowth on slash-cutover compared to cutover. It has been established that most of the resumption as pine on both slash-cutover and cutover was concentrated in the areas adjacent to three sides of the forest. With a decrease in sources of insemination (adjoining two sides of the forest), the density of undergrowth decreased markedly. In turn, in open areas on slash-cutover and cutover, the number of undergrowth was the smallest. The young growth of pine is characterized by a regular (random) with a transition to a scattered (uniform) type of placement on the slash-cutovers. In cutovers, the main placement type is group. On slash-cutovers, the main part of the trees belonged to the resumption, which appeared for 2–3 years after fires and subsequent felling. The resumption, which appeared both for the next year and for 4–5 years after the removal of the woodland, was insignificant. For 6-year after the fire and felling, the resumption completely ceased. On cutovers, the main part of the trees belonged to the resumption, which appeared for 4–5 years after felling. However, although to a much lesser extent, the resumption of pine on the cutovers, took place in subsequent years. The pattern of change in the age structure of undergrowth for cut-offs is well approximated by the polynomial equation of the 4th order, and on the cut-offs of the 5th order.

Age Structure and Growth in the Zamda Toad, Bufotes zamdaensis (Anura, Bufonidae)

2021 ◽  
Vol 28 (3) ◽  
pp. 138-144
Author(s):  
Sergey M. Lyapkov ◽  
Artem A. Kidov ◽  
Irina V. Stepankova ◽  
Kirill A. Afrin ◽  
Spartak N. Litvinchuk
Keyword(s):  
Growth Rate ◽  
Age Structure ◽  
Related Species ◽  
Mean Value ◽  
Himachal Pradesh ◽  
Closely Related Species

The paper provides the first data about age structure and growth of the Zamda toad, Bufotes zamdaensis (Boulenger, 1882), from the Himachal Pradesh State (India). The study of age structure of toads was carried out using skeletochronology. The minimal and maximal ages in males of B. zamdaensis were 4 and 7 years, respectively, with mean age of 5.4 years. The majority of males (60%) were 5 years old. The age in females ranged from 5 to 9 years with mean value of 6.1 years. The majority of females (71%) were 5 – 6 years old. Males of B. zamdaensis can reach maturation after four winterings and females after five winterings. Unlike closely related species B. latastii, the growth rate in both sexes does not decrease significantly after the 1st and 2nd wintering and remains high after the 3rd and 4th wintering.

scholarly journals Changes in age‐structure over four decades were a key determinant of population growth rate in a long‐lived mammal

2020 ◽  
Vol 89 (10) ◽  
pp. 2268-2278
Author(s):  
John Jackson ◽  
Khyne U. Mar ◽  
Win Htut ◽  
Dylan Z. Childs ◽  
Virpi Lummaa
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Age Structure ◽  
Population Growth Rate

Conserved growth rate and age structure of Xenopus laevis in the edge and core of an expanding population

2019 ◽  
Vol 128 (1) ◽  
pp. 122-129 ◽  
Author(s):  
Julien Courant ◽  
Layla Adil ◽  
Barbara De Kegel ◽  
Dominique Adriaens ◽  
Anthony Herrel
Keyword(s):  
Growth Rate ◽  
Xenopus Laevis ◽  
Age Structure ◽  
Reproductive Investment ◽  
Individual Growth ◽  
Evolutionary Mechanisms ◽  
Range Edge ◽  
Investment In Reproduction ◽  
Range Core ◽  
Expanding Population

Abstract Invasive species represent a unique opportunity to study the evolutionary mechanisms driving range expansions. Although range expansion is expected to be associated with increased reproduction and dispersal at the range edge, Xenopus laevis seems to decrease its reproductive investment and to enhance dispersal at the range edge. Evidence of increased dispersal at the edge of expanding populations occurring simultaneously with a faster growth rate has been reported for other organisms. Here, we focused on the growth rate and age structure at the range edge vs. the range core in an expanding population of X. laevis. We used skeletochronology to characterize the age of 250 individuals captured at the range core and edge of this expanding population. Using the Von Bertalanffy equation, we then compared individual growth rates between locations. We found no significant changes in growth rate or age structure between edge and core samples. This result suggests that the reduced investment in reproduction recorded in another study at the range edge might compensate for the increased dispersal without impacting growth in this population. This implies that the resource allocation in an expanding population might thus be more diverse than commonly assumed.

Trophic Structure, Reproductive Success, and Growth Rate of Fishes in a Natural and Modified Headwater Stream

1982 ◽  
Vol 39 (7) ◽  
pp. 968-978 ◽  
Author(s):  
Isaac J. Schlosser
Keyword(s):  
Growth Rate ◽  
Reproductive Success ◽  
Flow Regime ◽  
Age Structure ◽  
Trophic Structure ◽  
Headwater Stream ◽  
Organic Substrates ◽  
Age Classes ◽  
Younger Age ◽  
The Impact

The impact of removing riparian vegetation, channel straightening, and fluctuations in flow regime on trophic structure, reproductive success, and growth rate of fishes was assessed in a natural (Jordan Creek (JC)) and modified (Big Ditch (BD)) headwater stream in east-central Illinois. Shallow habitats and organic substrates increased more in BD than JC during low flow periods in summer. Insect densities in JC were highest in late spring, declining to low levels by late summer. Insect densities in BD were high throughout summer. Fish in JC were predominantly benthic insectivores and insectivore–piscivores; trophic structure, age structure, and biomass were stable between years and seasons; recruits made up a small and stable portion of community biomass and were primarily insectivore–piscivores and generalized insectivores; younger age-classes were in shallow riffle habitats. Adult fish and recruits in BD were predominantly generalized insectivores, omnivores, and herbivore–detritivores; the last two were primarily mid-river species (Carpoides cyprinus and Dorosoma cepedianum). Considerable seasonal and annual variation in trophic structure, total biomass, and age structure occurred in BD associated with annual fluctuations in flow regime, abundance of organic substrates, and reproductive success of mid-river species. Younger age-classes had higher summer growth rates in BD than JC. The temporally variable physical environment and unstable autotrophic energy base created in modified headwater streams are probably major factors responsible for recent shifts in large river fish communities in the midwestern United States from insectivore and insectivore–piscivore species to omnivores and herbivore–detritivores.Key words: community organization, fishes, Illinois, stream continuum, stream alteration, trophic ecology, warmwater stream

scholarly journals Evidences of Multicomponent Structure of the Migratory Stock and Morphological Distinctions of Shads from the Genus Alosa (Clupeaformes, Alosiinae) of the Sea of Azov

2013 ◽  
Vol 47 (1) ◽  
pp. 60-66
Author(s):  
S. V. Mezhzherin ◽  
O. V. Vernygora
Keyword(s):  
Growth Rate ◽  
Sex Ratio ◽  
Age Structure ◽  
Linear Size ◽  
Body Measurements ◽  
Sea Of Azov ◽  
Gill Rakers ◽  
Interspecific Differences ◽  
Kerch Strait ◽  
Seasonal Migrations

Abstract Migratory stocks of shads passing through the Kerch strait during their seasonal migrations consist of three groups of specimens, that can be identified based on the number of gill rakers on the first arch. These are so called Kerch shad A. maeotica (50.2 %), Pontic shad A. immaculata (48.7 %) and Caspian shad A. caspia (1.1 %). This ratio of species in the region remains stable for the last 60 years. Populations of Kerch and Pontic shads have similar age structure and sex ratio with a shift toward females 52-54 %. Specimens of A. maeotica have greater linear size and weight than those of A. immacuta, that indicates higher growth rate of the former. Analysis of 26 body measurements shows definite differences between these shads in their absolute features, there are also some differences in the proportions of the head. Nevertheless, degree and reproducibility of interspecific differences during various periods of time, do not allow for the reliable discrimination of specimens of these species assumed by some researchers

scholarly journals Studies on ectomycorrhizal basidiomycete in pine forest on the Lithuania-Poland transboundary region

2013 ◽  
Vol 42 (1) ◽  
pp. 59-68
Author(s):  
Danutė Stankovičienė ◽  
Jonas Kaspravičius
Keyword(s):  
Species Richness ◽  
Ectomycorrhizal Fungi ◽  
Main Part ◽  
Abundant Species ◽  
Pine Forest ◽  
Forest Diversity ◽  
Study Plot ◽  
Frequent Species

The diversity of ectomycorrhizal fungi and sporocarps abundance were investigated in 2003-2005 at nine permanent study plots in a 50-year-old pine forest. Diversity of ectomycorrhizal fungi consisted of 53 taxa and the majority of them belonged to the genera <em>Cortinarius, Russula, Amanita</em> and <em>Tricholoma</em>. The most frequent species, whose fruit bodies were found in each study plot, were <em>C. cibarius, L. necator L. rufus, P. involutus, R. aeruginea, T. saponaceum</em> and the most abundant species which made the main part of total sporocarp yield were <em>C. cibarius</em> and <em>P. involutus</em>. The lowest species richness of ectomycorrhizal fungi was in study plots with the densest cover of grasses. Maximum of species over the fruiting period was characteristic for October and for September. It was noticed that some species virtually never occurred together at the same plot (eg. <em>C. cibarius</em> and <em>H. aurantiaca</em>), meanwhile others occurred together quite frequently (eg. <em>H.aurantiaca</em> and <em>X. badius</em>).

scholarly journals Age and growth of European flounder from the Chupa Inlet (Kandalaksha Bay, the White Sea)

2019 ◽  
Vol 323 (2) ◽  
pp. 93-104 ◽  
Author(s):  
P.N. Yershov ◽  
A.A. Matvienko ◽  
D.A. Aristov
Keyword(s):  
Growth Rate ◽  
Age Structure ◽  
White Sea ◽  
The White Sea ◽  
North East ◽  
The North ◽  
Kandalaksha Bay ◽  
Onega Bay ◽  
European Flounder ◽  
Males And Females

We studied age structure, growth and distribution of European flounder Platichthys flesus at the sea in Chupa Inlet (Kandalaksha Bay, the White Sea). Immature and mature fishes fed at shallows of Chupa Inlet and adjacent open sea area in June-August. Size-age and sex composition of fishes in catches are presented in the paper. Individuals of 17–27 cm length and 4–5 year age constituted the majority of catches (45%). On the whole, males numerically predominated over females in the samples. Analysis of sexual differences of growth has shown that females grew faster than males. The most intensive growth took place in July–August, according to the increments on the otoliths. Growth rate of the flounder from Chupa Inlet appeared to be similar to the growth rate of the flounder from other open shore sites of Kandalaksha Bay. We have compared also peculiarities of growth and age structure of flounder populations from Kandalaksha Bay to those from other bays of the White Sea. Significant differences of the growth rate were found between flounders from Kandalaksha, Onega, Dvina and Mezen' Bays. Both males and females from Onega Bay grew faster than other. Growth rate of fish decreased towards the north (Kandalaksha Bay) and the north-east (Mezen' Bay). The most slow-growing flounder inhabited shallows of Mezen' Bay. Statistical analysis has shown that age structure of flounder populations varied in different bays of the White Sea, and observed regional variations were characteristic for both males and females. Flounder population in Onega Bay was characterized by the dominance of the younger individuals compared to populations in other bays. The greatest mean age of flounder was registered in populations from the north-west (Kandalaksha Bay) and the north-east (Mezen' Bay) parts of the White Sea. Males and females in populations from Onega and Dvina Bays differed significantly in the mean age, and as a rule females were older. No age differences between sexes were found in flounder population of Mezen' Bay. We suppose that temperature conditions were among the main factors influencing regional differences in growth rate and age structure of the flounder populations in the White Sea.

Age Structure and Growth in the Lataste’s Toad, Bufotes latastii (Anura: Bufonidae)

2020 ◽  
Vol 27 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Sergey Marlenovich Lyapkov ◽  
Artem Aleksandrovich Kidov ◽  
Irina Vladimirovna Stepankova ◽  
Kirill Aleksandrovich Afrin ◽  
Spartak Nikolaevich Litvinchuk
Keyword(s):  
Growth Rate ◽  
Body Length ◽  
Age Structure ◽  
Mean Value ◽  
The Body ◽  
Jammu And Kashmir ◽  
Different Ages ◽  
Length Increment

The paper provided the first data about age structure and growth of the Lataste’s toad, Bufotes latastii (Boulenger, 1882), from the Jammu and Kashmir State (India). The study of age structure of toads was carried out using skeletochronology. The minimal and maximal ages in males of B. latastii were 3 and 10 years, respectively, with mean age of 6.0 years. The majority of males (70%) were 5 or 6 years old. The age in females ranged from 4 to 10 years with mean value of 5.9 years. The majority of females (71%) were 4 – 6 years old. Males of B. latastii can reach maturation after three winterings and females after four winterings. The body length increment in males is 3.6 times, whereas in females is 3.7 – 4.0 times. After maturation, the growth rate is retarded and the individuals of different ages did not differ in its body length. In spite of maximal age of 10 years in both sexes, the largest male was 5 years old and the largest female was 4 years old.

Structured Population Models

2021 ◽  
pp. 47-60
Author(s):  
Timothy E. Essington
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Matrix Model ◽  
Age Structure ◽  
Population Growth Rate ◽  
Population Models ◽  
State Variables ◽  
Elasticity Analysis ◽  
Structured Population Models ◽  
Structured Population

The chapter “Structured Population Models” illustrates how one adds more detail to a model, first through density-independent models, then by showing common matrix-model formulations and how those are used to reveal properties of structured models (e.g. population growth rate, stage/age structure). Structured population models have more detail than their nonstructured counterparts. They account for the differences among individuals within a population, usually by explicitly modeling them as distinct state variables. Elasticity analysis is introduced as a way to identify life stages that have a disproportionately large influence on population growth rate. Structured density-dependent models are briefly introduced as extensions on these models.

Sign in / Sign up

Export Citation Format

Share Document