TO THE BIOLOGY OF OENANTHE AQUATICA (L.) POIR. (UMBELLIFLORAE)

The results of experiments on seed germination and the initial stages of ontogenesis of the hygrohelophyte Oenanthe aquatica under laboratory conditions are presented. The features of fruit germination and the initial stages of ontogenesis of Oenanthe aquatica (L.) Poir were studied. It was revealed that mature fruits of O. aquatica do not have a dormant period. Germination of both freshly harvested fruits and those subjected to various storage conditions for 4 months (in laboratory conditions, refrigerator and freezer), showed a high percentage of laboratory germination from 90.6 to 100%. At the same time, storage of fruits in the freezer and in the refrigerator led to a decrease in the lag-time and germination period (in comparison with those of freshly picked fruits and fruits stored at room temperature). It was revealed that the fruits of O. aquatica germinate without a dormant period. It was shown that the development of O. aquatica seedling under laboratory conditions lasts about 30 days. The transition of a plant to a juvenile ontogenetic state occurs when the cotyledon leaves die off and is accompanied by the appearance of all the main plant organs. The sprout is a monopodially growing rosette shoot with main and adventitious roots. The juvenile plant is also represented by a uniaxial monopodial and anisotropic rosette shoot. The transition to an immature age-related state is characterized by the preservation of the rosette form of growth and the appearance of axillary buds on the shoot. In juvenile and immature age states, plants usually hibernate. It was revealed that already at the seedling stage, the polyvariance of ontogenesis is traced according to the rates of development of plants (growing in Petri dishes and floating on the surface of the water in beakers), associated with different rates of plant transition from the seedling phase to the juvenile age state.

Lateglacial and Holocene floras and faunas from the Salpetermosen area, north-east Sjælland, Denmark

The Salpetermosen area in north-east Sjælland, Denmark, was deglaciated about 18 000 to 17 000 years ago. Melting of bodies of stagnant glacier ice led to the for-mation of kettle holes, which contain Lateglacial and Holocene sediments with remains of plants and animals that provide information on the past flora and fauna of the area. During the Allerød period, open forests with Betula pubescens (downy birch) characterised the area, the flora included light-demanding species such as Arctostaphylos uva-ursi (bearberry), Empetrum nigrum (crowberry) and rare Populus tremula (aspen), Betula nana (dwarf birch) and Rubus saxatilis (stone bramble), as well as the thermophilous swamp plant Oenanthe aquatica (fine-leaved water dropwort). During the Younger Dryas, the vegetation was characterised by dwarf-shrub heaths dominated by Betula nana, but including Dryas octopetala (mountain avens), Salix herbacea (least willow), Arctostaphylos alpina (alpine bearberry,) and rare Betula pube-scens, as well as the thermophilous plants Urtica dioeca (stinging nettle) and Lychnis flos-cuculi (ragged robin). The Early Holocene forests were dominated by Betula pubescens, Populus tremula and Pinus sylvestris (scots pine), but included rare Betula nana. Alnus glutinosa (alder) arrived at c. 10 000 cal. years BP. The calciphilous sedge Cladium mariscus (fen-sedge) and the macrolimnophyte Najas marina (spiny naiad) were common. The Late Holocene flora included the acidophilous plant Scheuchzeria palustris (rannoch-rush).

ФИТОСОЦИОЛОГИЧЕСКИЙ АНАЛИЗ ОСУШАЕМОГО ЛАНДШАФТА

Кормовая значимость лугов, используемых в качестве сенокосов и пастбищ, снижается от произрастания на них ядовитых растений. К ядовитым относятся растения, поедание которых вызывает у животных серьезные отравления, а в некоторых случаях приводит к гибели животных. Ядовитость обусловлена содержанием в них особых химически активных действующих соединений. Цель исследований проведение геоботанического обследования луга на территории мелиоративного объекта Тинки-II на землях Рязанской Мещеры для определения ботанического состава луговых трав, выявления и степени обилия на нем ядовитых растений. Местоположение луга близ д. Полково Рязанского района Рязанской области. Обследование проведено на площади 10000 м2 в июле 2019 года при предварительном рекогносцировочном осмотре территории по ходу рабочих маршрутов. Методика исследований общепринятая. В результате проведенного обследования территории установлены растения доминанты Elytrgia repens и Alopecurus pratensis с частой встречаемостью и высокой степенью обилия. В результате изучения растительного покрова на обследуемом участке луга выделена ассоциация Elytrgetum urtcetosum. Растения произрастали сплошным ковром и покрытие почвы составляло до 100. Общее количество ядовитых растений составило 102 экземпляра из 6 семейств. Наиболее часто встречающиеся ядовитые растения представлены семействами Зонтичные (Apiaceae) и Лютиковые (Ranunculaceae). Доля участия каждого ядовитого компонента: Conium maculatum 36, Chaerophyllum temulum, Cicuta virosa 29, Oenanthe aquatica, Thalictrum aquilegiifolium 15, Caltha palustris, Anemone ranunculoides 8, Calla palustris, Pedicularis palustris, Glechoma hederacea, Persicaria hydropiper по 12. Таким образом, видовой состав луговых трав обеднен и мала вероятность отравления сельскохозяйственных животных, так как наличие ядовитых растений незначительно, с учетом их негативного влияния на организм животного только при определенной дозе и сроке экспозиции.The fodder value of meadows used as hayfields and pastures decreases because of the growth of poisonous plants on them. Poisonous plants are those that cause serious poisoning in animals that consume them, and in some cases it leads to death of the animals. The toxicity is due to the content of special reactive compounds in them. The research objective is to conduct a geobotanical survey of the meadow on the territory of the Tinky-II reclamation site on the lands of the Ryazan Meshchera to determine the botanical composition of meadow grasses, to identify and determine the abundance of poisonous plants on it. The location of the meadow is near the village of Polkovo, Ryazan district, Ryazan region. The survey covered the area of 10,000 m2 in July 2019 during a preliminary reconnaissance survey of the territory along the working routes. The research methodology is generally acknowledged. As a result of the territory survey, it was established that the dominant plants are Elytrgia repens and Alopecurus pratensis, that occur frequently and have a high degree of abundance. As a result of studying the vegetation cover, the association Elytrgetum urtcetosum was distinguished in the examined area of the meadow. The plants grew with a continuous carpet and the soil cover was up to 100. The total number of poisonous plants was 102 from 6 families. The most common poisonous plants are represented by the Apiaceae and Ranunculaceae families. The share of each poisonous component: Conium maculatum - 36, Chaerophyllum temulum, Cicuta virosa - 29, Oenanthe aquatica, Thalictrum aquilegiifolium - 15, Caltha palustris, Anemone ranunculoides - 8, Calla palustris, Pedicularis palustris pa riceprica, hydrachlecha - 12 each. Thus, the species composition of meadow grasses is depleted and there is little chance of poisoning of farm animals, since the presence of poisonous plants is insignificant, taking into account their negative impact on the animals body only at a certain dose and duration of exposure.