Female reproductive suppression in an Australian arid zone rodent, the spinifex hopping mouse

2020 ◽  
Vol 312 (3) ◽  
pp. 163-173
Author(s):  
K. K. Berris ◽  
W. G. Breed ◽  
K. E. Moseby ◽  
S. M. Carthew
2013 ◽  
Vol 25 (1-2) ◽  
pp. 136-148
Author(s):  
I. V. Gryb

The concept of an explosion in freshwater ecosystems as a result of the release of accumulated energy, accompanied by the destruction of the steady climax successions of hydrocenoses is presented. The typification of local explosions as well as methods for assessing their risk during the development of river basins are shown. The change in atmospheric circulation, impaired phases of the hydrological regime of rivers, increasing the average temperature of the planet, including in Polesie to 0,6 ºC, deforestation leads to concentration and release of huge amounts of unmanaged terrestrial energy, which manifests itself in the form of disasters and emergencies. Hydroecological explosion is formed as a result of multifactorial external influence (natural and anthropogenic) on the water body in a certain period of time. Moreover, its level at wastewater discharge depends on the mass of recycled impurities and behaved processing capacity of the reservoir, and the mass of dumped on biocides and the possibility of the water flow to their dilution and to the utilization of non-toxic concentrations. In all these cases the preservation of "centers of life" in the tributaries of the first order – local fish reproduction areas contributed to ecosystem recovery, and the entire ecosystem has evolved from equilibrium to non-equilibrium with further restructuring after the explosion and environmental transition to a new trophic level. It means that hydroecological explosion can be researched as the logical course of development of living matter in abiotic environmental conditions, ending abruptly with the formation of new species composition cenoses and new bio-productivity. The buffer capacity of the water environment is reduced due to re-development and anthropic transformation of geobiocenoses of river basins, which leads to a weakening of life resistance. This applies particularly to the southern industrial regions of Ukraine, located in the arid zone that is even more relevant in the context of increased average temperature due to the greenhouse effect, as well as to Polesie (Western, Central and Chernihiv), had been exposed to large-scale drainage of 60-80th years, which contributed to the degradation of peatlands and fitostroma. Imposing the western trace of emissions from the Chernobyl accident to these areas had created the conditions of prolonged hydroecological explosion in an intense process of aging water bodies, especially lakes, change in species composition of fish fauna and the occurrence of neoplasms at the organismal level. Under these conditions, for the existence of man and the environment the vitaukta should be strengthened, i.e. buffer resistance and capacitance the aquatic environment, bioefficiency on the one hand and balanced using the energy deposited - on the other. This will restore the functioning of ecosystems "channel-floodplain", "riverbed-lake", reducing the energy load on the aquatic environment. Hydroecological explosions of natural origin can not be considered a pathology – it is a jump process of natural selection of species of biota. Another thing, if they are of anthropogenic origin and if the magnitude of such an impact is on the power of geological factors. Hydroecological explosions can be regarded as a manifestation of environmental wars that consciously or unconsciously, human society is waging against themselves and their kind in the river basins, so prevention of entropy increase in the aquatic environment and the prevention of hydroecological explosions is a matter of human survival. While the man - is not the final link in the development of living matter, it can develop without him, as matter is eternal, and the forms of its existence are different.


2019 ◽  
pp. 55-70
Author(s):  
И.Р. Грибуст

Введение. Лесомелиоративное обустройство территорий малолесных регионов коренным образом преобразует ранее пустынные пространства. Позитивные изменения влажностнотеплового, почвенного, гидрологического режимов, обогащение аборигенной дендрофлоры новыми видами влечет за собой также и трансформацию животного мира, в том числе населения насекомых. Энтомосообщества формируются за счет представителей степной группы, обитателей естественных ценозов, а также группы лесных насекомых, в числе которых виды, являющиеся опасными вредителями и их энтомофаги. Цель работы анализ изменения разнообразия насекомыхэнтомофагов в насаждениях засушливой зоны различных параметров и состояния. Объекты исследований насекомыеэнтомофаги, обитающие в энтомокомплексах защитных насаждениях различного дендрологического состава ФНЦ агроэкологии РАН на территории Волгоградской области (кадастр. 34:34:000000:122 34:08:000000:6). Материалы и методика. Сбор материала проводили в насаждениях различного хозяйственного значения. Объектами исследования являлись полезные насекомые. Отбор проб проводили посредством окашивания крон энтомологическим сачком, визуальным осмотром модельных ветвей и ручным сбором хищников и паразитированных видов филлофагов с последующим выведением имаго в лабораторных условиях. Результаты и обсуждение. В сообществе полезных насекомых защитных лесных насаждений сухостепной зоны зафиксирован 221 вид энтомофагов, относящихся к 7 отрядам и 32 семействам. Различия экологических условий, ассортимент древесных растений в каждой из посадок, характер и интенсивность негативного внешнего влияния определяют особенности фаунистического населения, в т. ч. энтомофагов. Оценка распределения количественного обилия паразитов и хищников показала, что в лесных полосах хищников в среднем в три раза больше паразитических насекомых. Отчетливо прослеживаются вариации изменения разнообразия энтомофагов в насаждениях разного класса жизнеспособности. Конструктивные особенности, флористическая обедненность и сформировавшийся микроклимат существенно ограничивает жизнедеятельность энтомофагов в малорядных (23 ряда) насаждениях, численность которых здесь снижается в среднем в 2,5 раза по сравнению с многорядными посадками. В вертикальном градиенте посадок по мощности накопления биотического потенциала полезных насекомых выделяется травянистый ярус, наличие которого в лесополосе обусловливает увеличение числа особей энтомофагов в сообществе в 1,32,7 раза. Наименьшую роль в накоплении полезной группы насекомых играет наличие развитого подлеска. Заключение. Наличие в насаждениях энтомофильных древесных растений и развитого травостоя важнейшие экологические факторы для накопления биотического потенциала энтомофагов. Максимальный эффект обеспечивает совокупное влияние определяющих экологоструктурных элементов в многорядных посадках. Introduction. Forest reclamation area developmentpoor regions is radically transforms the previously desolate space. Positive changes in moistureheat, soil, hydrological regimes, enrichment of native dendroflora with new species also entails the transformation of the animal world, including the insect population. Entomologiste formed by the representatives of the steppe group of the inhabitants of the natural coenoses, and the group of forest insects, including species that are dangerous pests and their entomophages. The purpose of the analysis of changes in the diversity of insect entomophages in the plantations of the arid zone of different parameters and conditions. The objects of research insectsentomophages living in entomocomplexes protective plantation of different dendrological composition of the Federal scientific center for Agroecology wounds on the territory of the Volgograd region (the cadaster number is 34:34:000000:122 34:08:000000:6). Materials and methods. Collection of material was carried out in plantations of various economic importance. The objects of study were useful insects. Samples were collected by hilling crowns entomological net, by visual inspection of the model branches and handcollection of predators and parasitism species of phyllophagous with subsequent excretion of adults in the laboratory. Results and discussion. 221 species of entomophages belonging to 7 groups and 32 families were recorded in the community of useful insects of protective forest plantations of the dry steppe zone. Differences in environmental conditions, the range of woody plants in each of the plantings, the nature and intensity of the negative external influence determine the characteristics of the faunal population, including entomophages The estimation of distribution of quantitative abundance of parasites and predators showed that in forest bands of predators on average three times more parasitic insects. Variations in the diversity of entomophages in plantings of different classes of viability are clearly observed. Design features, floristic depletion and formed microclimate significantly limits the life activity of entomophages in smallrow (23 rows) plantations, the number of which is reduced by an average of 2.5 times compared to multirow planting. In the vertical gradient of plantings on the power of accumulation of biotic potential of useful insects, a grassy tier is allocated, the presence of which in the forest belt causes an increase in the number of entomophages in the community by 1.32.7 times. The least role in the accumulation of a useful group of insects is played by the presence of developed undergrowth. Conclusion. The presence of entomophilic woody plants and developed herbage in the plantations are the most important environmental factors for the accumulation of the entomophage biotic potential. The maximum effect provides a cumulative effect of determining ecological and structural elements in multirow landings.


2010 ◽  
Vol 9 (4) ◽  
pp. 541-546
Author(s):  
Florian Statescu ◽  
Dorin Cotiusca Zauca ◽  
Constantin Victor Statescu
Keyword(s):  

The present study was carried out in three districts viz; Rewari, Sirsa and Hisar of Haryana state. A survey of 60 sampled farms was conducted to extract information pertaining to various expenses incurred in cultivation of castor and output attained as well as to ascertain the perception of farmers for various problems encountered in production and marketing of castor seed. The descriptive analysis was employed to draw valid inferences from the study. The results revealed that net profit accrued from cultivation of castor seed was ₹ 46331 ha -1 in the study area. The value of B: C ratio of castor cultivation was more than one and also higher as compared to prevalent cropping systems indicated that cultivation of castor seed is economical viable entity. However, production constraints like retention of F2 seed in the field over year, grain scattering, shortage of irrigation water, frost effect on crop yield and marketing constraints like absence of MSP, higher transportation cost sale of castor seed in distant markets, frequent fluctuation in market price, non-availability of processing units were observed.


Peanuts are plants of the tropical zone, therefore, for its growth and development, high temperature indicators are needed during a fairly long growing season. The climatic parameters of the south of Ukraine correspond to the needs of this culture, and today there is positive experience in growing peanuts in this region. In order to increase the efficiency of growing peanuts in the conditions of the Steppe zone, it is necessary to carry out genetic selection work to study and select a more adapted source material in order to create highly productive Ukrainian varieties adapted to the arid zone conditions. At the initial stage of this work, it is necessary to have clear signs and characteristics for evaluating the studied genotypes, and the existing methods for describing the characters and conducting an examination for distinctness, uniformity, and stability are incomplete and do not meet the requirements for in-depth work on private genetics and culture breeding. For our work, we used 18 peanut genotypes as a material, which make up the collection of the Institute of Oilseeds of NAASU. Studies were carried out in 2018 and 2019, in different weather conditions. All measurements, observations and statistical processing in the study of samples were carried out in accordance with generally accepted methods. When conducting a comparative analysis of the two methods for describing the signs of underground peanuts, it was found that one of the methods contains 23 signs and the other 17. The signs of the vegetative part of plants that characterize the habit and structure of the leaf predominate in both methods. We have identified and proposed for description 9 new characters in peanut plants: 2 - leaf characters (additional leaves and pubescence); 1 - the structure of beans (weight 100 beans); 1 - an economically valuable trait (the presence of nodules on the roots); 5 - flower features (size and color of the flower and border). In terms of plant habitat, Ukrainian Stepnyak and Krasnodar 13 varieties were distinguished, which had the highest height (43.8 cm) and the largest number of branches (9.3 pcs.). In addition to morphological identification features for the description and examination of distinctness, uniformity and stability, we have also studied the quantitative characteristics of underground peanuts. It was established that the height of peanut plants in the field conditions of the south of Ukraine ranged from 14 to 44 cm. The highest variety was the Ukrainian Stepnyak variety, and the shortest one was Pink large. The largest number of branches is 9.3 pcs. noted in the variety Krasnodar 13, and the smallest 4.62 pcs. - at L3. And the largest flower of 1.91 cm stood out White-pink 3. The quantitative traits we studied are characterized by continuous variability, which is due to the interaction between genes and the environment. Thus, to identify varietal variability in underground peanuts, it is necessary to use both existing methods, and in the near future, work should be done to combine them with the inclusion of new identified characters to more clearly identify the genotypes of this new valuable oilseed crop.


Soil Horizons ◽  
1962 ◽  
Vol 3 (2) ◽  
pp. 18 ◽  
Author(s):  
John Doe
Keyword(s):  

1974 ◽  
Vol 38 (6) ◽  
pp. viii-viii
Author(s):  
D. E. Miller
Keyword(s):  

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