Year-class coexistence in biennial plants

2012 ◽  
Vol 82 (1) ◽  
pp. 18-21 ◽  
Author(s):  
Éva Kisdi
Keyword(s):  
Biennial Plants

“Data for the Problem of Evolution in Man. V. On the Correlation between Duration of Life and the Number of Offspring”

1901 ◽  
Vol 35 (6) ◽  
pp. 458-479
Author(s):  
M. Beeton ◽  
G. U. Yule ◽  
Karl Pearson
Keyword(s):  
Natural Selection ◽  
Breeding Season ◽  
The Other ◽  
Similar Statement ◽  
Men And Women ◽  
Darwinian Theory ◽  
Theory Of Evolution ◽  
Biennial Plants ◽  
Long Life ◽  
Breeding Seasons

According to the Darwinian theory of evolution the members of a community less fitted to their environment are removed by death. But this process of natural selection would not permanently modify a race, if the members thus removed were able before death to propagate their species in average numbers. It then becomes an important question to ascertain how far duration of life is related to fertility. In the case of many insects death can interfere only with their single chance of offspring; they live or not for their one breeding season only. A similar statement holds good with regard to annual and biennial plants. In such cases there might still be a correlation between duration of life and fertility, but it would be of the indirect character, which we actually find in the case of men and women living beyond sixty years of age—a long life means better physique and better physique increased fertility. On the other hand, there is a direct correlation of fertility and duration of life in the case of those animals which generally survive a number of breeding seasons, and it is this correlation which we had at first in view when investigating the influence of duration of life on fertility in man. The discovery of the indirect factor in the correlation referred to above was therefore a point of much interest. For it seems to show that the physique fittest to survive is really the physique which is in itself (and independently of the duration of life) most fecund.

scholarly journals Data for the problem of evolution in man. V. On the correlation between duration of life and the number of offspring

1901 ◽  
Vol 67 (435-441) ◽  
pp. 159-179 ◽  
Keyword(s):  
Natural Selection ◽  
Breeding Season ◽  
Similar Statement ◽  
Darwinian Theory ◽  
Theory Of Evolution ◽  
Biennial Plants

According to the Darwinian theory of evolution the members of a community less fitted^ to their environment are removed by death. But this process of natural selection would not permanently modify a race, if the members thus removed were able before death to propagate their species in average numbers. It then becomes an important question to ascertain how far duration of life is related to fertility. In the case of many insects death can interfere only with their single chance of offspring they live or not for their one breeding season only. A similar statement holds good with regard to annual and biennial plants.

scholarly journals SYSTEMATIC, BIOMORPHOLOGICAL AND ENVIRONMENTAL ANALYSIS OF WILD-GROWING PLANTS OF PEREYASLAV

2020 ◽  
pp. 27-36
Author(s):  
Л. І. Довгопола
Keyword(s):  
Medicinal Plants ◽  
Life Form ◽  
Geographical Location ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Annual Plants ◽  
Ecological Analysis ◽  
Field Surveys ◽  
Biennial Plants ◽  
Systematic Composition

The peculiarity of the geographical location of the Pereyaslav Region, the existence of dense river nets (the Dnieper River, the Trubizh River, the Alta River, the Supiy River, etc.) and the diversity of landscapes led to the formation of the region rich in plant species. However, the vegetation cover of the region has been significantly transformed as a result of the construction of a hydroelectric power plant on the Dnieper River and the creation of the Kaniv Reservoir. The purpose of the article is to carry out a systematic, biomorphological and ecological analysis of the composition of wild medicinal plants of the Pereyaslav region. The research was conducted during 2018-2019 years on the territory of the Pereyaslav Region. The object of the study is the flora of wild medicinal plants of the Pereyaslav Region. The study was performed by means of the route, stationary and semi-stationary methods. During the field surveys (geobotanical descriptions) of the studied territory, the flora was described, species and families of the plants were determined, their location and ecological conditions of growth, life form, etc. were noted. As a result of the critical inventory of the species composition of the Pereyaslav flora, the systematic composition of wild herbs and medicinal plants of the region was first developed (582 species), consisting of 106 families and 360 species, among which there are vascular plants (Lycopodiophyta, Equisetophyta, Polypodiophyta) – 15 species, Pinophyta – 3 species, Magnoliophyta – 567 species. The biomorphological analysis of wild herbs and medicinal plants of the Pereyaslav Region was performed and it was established that the vast majority of species belong to hemicryptophytes (316 species). It was found that in the studied territory the diversity of wild medicinal plants is represented by trees (27 species), shrubs (28 species), subshrubs (10 species), perennial herbaceous plants (387 species), biennial plants (46 species) and annual plants (84 species). It has been established that the ecological-coenotic nature of valuable species of plants in the study consists of forest (170 species), meadow (145 species), meadow-steppe (114 species), synanthropic phytocenoses consist of 95 species and wetland ecotopes – 58 species.

scholarly journals FLORA OF LAWNS IN THE CITY OF UFA

2019 ◽  
Vol 54 (4) ◽  
pp. 24-30
Author(s):  
L.M. Ishbirdina ◽  
◽  
L.N. Blonskaya ◽  
A.Sh. Timeryanov ◽  
S.I. Konashova ◽  
...  
Keyword(s):  
Life Form ◽  
Chenopodium Album ◽  
Taraxacum Officinale ◽  
Soil Disturbance ◽  
Gramineous Plant ◽  
Bidens Tripartita ◽  
Species Activity ◽  
Biennial Plants ◽  
Urban Lawns ◽  
The City

The paper presents a study in the flora of lawns in Ufa. The lawn flora is represented by 192 species belonging to 31 families. Based on coenotic and ecological characteristics, four ecological coenotic groups of species were singled out that were described in the lawn designated areas. The ecological coenotic groups were analysed for life form spectra, hemeroby, species activity. Among the plant communities of typical low-trampled and well-maintained urban lawns (the ecological coenotic group of Festuca pratensis) Poaceae, Asteraceae, Fabaceae, Rosaceae, Apiaceae families were the leading ones, where hemicryptophytes and oligo-meso-αeuhemerobes dominated. The lawns subjected to significant anthropogenic impact (trampling, salinization) (the ecological coenotic group of Taraxacum officinale) had a large number of species that belonged to the «ruderal» Polygonaceae, Asteraceae, Fabaceae, Brassicaceae, Lamiaceae families, where hemicryptophytes and meso-euhemerobes dominated. Ruderal species of Asteraceae, Poaceae, Amaranthaceae, Lamiaceae, Malvaceae, Polygonaceae families prevailed, with a large share of ruderal and semi-ruderal annual and biennial plants, β-eupolyhemerobes, in the lawn designated areas where gramineous plant community did not develop after soil disturbance (the ecological coenotic group of Chenopodium album). Ruderal species of Poaceae, Chenopodiaceae, Polygonaceae families with a large portion of ruderal annual and biennial β-eupolyhemerobes also dominated in humid and waterlogged lawn areas. The ecological ecoenotic groups of Taraxacum officinale, Chenopodium album and Bidens tripartita had a large number of neophyte species. The lawn areas with the ecological coenotic groups of Taraxacum officinale, Chenopodium album and Bidens tripartite were found as most colonized with ruderal plants. A number of measures are required to build dense grass covering: reconstruction and heavy maintenance of lawns combined with sowing quality lawn grass mixtures, regular mowing practices to reduce the number of ruderal hemytherophytes and therophytes, timely plant nutrition and watering.

scholarly journals Diversity of roots and root systems in pauciennial dicots

2021 ◽  
pp. 107-133
Author(s):  
Михаил Витальевич Марков ◽  
Виолетта Закировн Юсуфова ◽  
Татьяна Андреевна Шестова ◽  
Дмитрий Олегович Грушенков
Keyword(s):  
Root Morphology ◽  
Lateral Roots ◽  
Root Systems ◽  
Negative Influence ◽  
Flowering Plant ◽  
Plant Group ◽  
Full Picture ◽  
Biennial Plants ◽  
Natural Diversity ◽  
Group Diversity

Исторически сложившийся в ботанике стереотип представлений об аллоризном строении корней и корневых систем малолетних (одно-двулетних) растений из класса Двудольных может стать серьезной помехой для объективной оценки разнообразия этой интереснейшей группы жизненных форм цветковых растений. При более внимательном изучении морфологии и анатомии корней в динамике их онтогенетического развития выявляется существенная неполнота наших знаний в этой области и отсутствие необходимого уровня развития терминологии, которые сказываются на содержательности изданных учебных пособий. Рассмотренные в этих пособиях хрестоматийные примеры дают далеко не полную картину природного разнообразия морфологической и анатомической структуры корней и в них, часто бывают недооценены или просто опущены важные детали в процессе их развития. К числу таких деталей относится коллет - структура в переходной зоне между главным корнем и гипокотилем, которой свойственна своя анатомия и морфология (развитие волосков или ризоидов), включая примордии боковых корней, закладывающихся внутри коллета иногда еще в ходе эмбриогенеза. Historically borned stereotype on allorhizy of pauciennial (annual-biennial) plants from Dicots can be valuable interference for objective representations (describing) of this extremely interesting flowering plant group diversity. Via more attentive and deep research of the morphology and anatomy of roots in their ontogenetic development dynamics we can observe (reveal) ncompleteness of our knowledge in this area and unsufficient level of terminology which could have negative influence on our published text-books content. Hackneyed examples that were presented in these text-books can illustrate far from the full picture of natural diversity of root morphology and anatomy with some valuable details of their development obviously underestimated or simply omitted. There is a collet amongst these details - more or less inflated transition zone between radicle and hypocotyl with its own anatomy and morphology features (cover from trichomes or rhyzoides), including lateral roots primordia which can be initiated inside even during embryogenesis.

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