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1.
The topic of carbon sequestration in plants has received much attention recently due to concerns about global climate change, which is being exacerbated by deforestation. In the early days of the global bioenergy boom, the private sector and non-government organizations enthusiastically promoted the planting of Jatropha curcas L. as a key candidate shrub species for the production of bioenergy in West Africa. This study investigates the aboveground biomass production and carbon sequestration potential of J. curcas, which is already widely cultivated for the production of oil seeds, biodiesel and biokerosene. The specific objective is to use a destructive method to develop allometric prediction equations of the aboveground biomass production of J. curcas plantations. 38 J. curcas shrubs were harvested and weighed in order to estimate biomass production. These data were used to develop allometric equations for the estimation of wood, leaf and total aboveground biomass production. The best-fit models found for estimating shrub component biomass and total aboveground biomass production were of the power form. All of the regression equations relating the prediction of leaf biomass, wood biomass and total aboveground biomass with J. curcas diameter at 20 cm above the ground (D) were statistically significant (p < 0.001) and also presented the highest goodness of fit (high R 2). The aboveground biomass carbon content was estimated using the ash method. Carbon content in leaves and wood was, respectively, 48 and 54 %. The current established allometric equations can be helpful to provide a rapid estimation of the aboveground biomass and C stock for J. curcas biofuel projects in semi-arid conditions.  相似文献   

2.
The composition and structure of the Gray mussel (Crenomytilus grayanus) community in Vostok Bay of the Sea of Japan have been studied. A total of 165 species have been identified in the macrobenthos. Its species composition has changed insignificantly since the 1970s. The total biomass of the biocenosis has decreased, and the size-age composition of the C. grayanus population has changed due to poaching. The trophic structure of the community has also changed, with the Shannon indices of species diversity and equitability (E) becoming lower, due to intensive organic pollution of Vostok Bay resulting from increasing recreational activities and sewage discharge.  相似文献   

3.
Experimental studies of interactions between two amphipod species (Gmelinoides fasciatus and Gammarus lacustris) showed that predation is the basic mechanism accounting for their mutual exclusion in nature. Mortality from predation among similar-sized specimens of both species at an equal abundance ratio was similar (24–25% in G. lacustris and 27–30% in G. fasciatus). The displacement of G. lacustris by G. fasciatus was observed when the latter was dominant. Adult G. fasciatus and G. lacustris successfully preyed on juveniles of their competitors and did not differ significantly in daily food consumption as a percentage of body weight: 6–24% at a fresh body weight of 18–24 mg in both species. The potential for rapid population growth under new conditions contributed to the success of the invasive Baikal species G. fasciatus in displacing G. lacustris from many water bodies of Russia.  相似文献   

4.
Gradients of Nei's genetic distances between 15 samples of Pinus sylvestris L. trees were analyzed along three submeridional transects, from Scandinavia to the Mediterranean and Transcaucasia. As a result, distinct chorogenetic differentiation was revealed between the populations of this species growing in climatically specific regions of northern and southern Europe. Considerable Nei's distances (DN = 0.045–0.056) and their gradients, combined with differences in stable phenotypic characters (the composition of monoterpenes and morphological parameters of cones) determined at the Pyrenean and Caucasian mountain borders, suggest that the P. sylvestris species structure includes two South Eurasian subspecies, the Pyrenean P. sylvestris L., ssp. iberica Svoboda and the Transcaucasian P. sylvestris L., ssp. hamata (Stev.) Fomin.  相似文献   

5.
Eomecon chionantha Hance, the only species in the genus Eomecon, is an angiosperm species endemic to China. Here we investigated the pollination syndrome, pollinator generalization of E. chionantha. Our results showed that the individual flower longevity of E. chionantha was 3–5 days. The flowering phenology of E. chionantha can be divided into five phases. We found significant differences in the pollination efficiency of the different insects visiting E. chionantha with bees and flies being the most efficient pollinators. This, in addition to floral morphology and phenology, suggests that E. chionantha is generalized on bees and flies and possesses an outcrossing, partially self-compatible and pollinator-dependent breeding system.  相似文献   

6.
It is shown that the basidiocarps of many wood-decomposing fungi are inhabited by taxonomically and biomorphologically various eukaryotic (Charophyta, Chlorophyta, and Ochrophyta) and prokaryotic (Cyanophyta/Cyanobacteria) algae. They represent widespread eurybiont species and do not include any specialized mycetobionts. The communities formed by them have a host preference and green algae are their basic and obligate component, while other organisms are facultative components. Basidiocarps in which mycetobionts include heterocytic cyanoprokaryotes (Anabaena sp., Calothrix parietina, Hassallia byssoidea, Nostoc commune, N. punctiforme, Nostoc sp., and Scytonema ocellatum) are capable of molecular nitrogen fixation. Its activity is 0.044–0.903 mg of C2H4/m2/h in the basidiocarps of Bjerkandera adusta, Cerrena unicolor, Gloeophyllum sepiarium, and Trametes ochracea and 0.001–0.008 mg of C2H4/m2/h in the basidiocarps of Onnia leporina, Phellinus chrysoloma, Ph. tremulae, and Trametes pubescens. Basidiocarps without algae and those inhabited only by eukaryotic algae have no nitrogenase activity.  相似文献   

7.
The taxonomic diversity of the Hirudinea fauna and its dependence on the ecological conditions in the Bukhtarma Reservoir (Eastern Kazakhstan) have been studied. The morphological analysis has shown that these leeches belong to two orders and three families: Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and Arhynchobdellida (family Erpobdellidae). On the whole, eight leech species from five genera (Alboglossiphonia, Helobdella, Theromyzon, Piscicola, and Erpobdella) have been identified. Among them, there are three glossiphoniid species (A. heteroclite, H. stagnalis, and T. tessulatum), two species of piscicolids (Piscicola geometra and Piscicola sp.), and three species of predatory leeches (E. octoculata, E. vilnensis, and Erpobdella sp.). Possible effects of hydrochemical parameters of the aquatic environment on the species diversity have been analyzed. Correlation has been revealed between the abundance of species and the physical and chemical characteristics of the environment.  相似文献   

8.
Accelerated aging of Drosophila strains with impaired detoxification of free radicals (Sod) and DNA repair (mus-210) under illumination as compared to the wild type has been demonstrated. In contrast, in a strain carrying a defective homolog of mammalian gene PCNA, the life span increases under conditions of round-the-clock illumination compared to constant darkness. The first review of the possible mechanisms underlying the effect of the illumination regime on the life span is presented, with special emphasis on the roles of the disturbance of normal circadian rhythms, increase in fecundity and physical activity (metabolic rate), and the neuroendocrine control of the insulin/IGF-1 pathway.  相似文献   

9.
Molecular genetic methods (AFLP and ITS1–5.8S–ITS2 rDNA analysis) have been used to study the level and structure of genetic diversity in relict populations of the Ural endemic Gypsophila uralensis Less. in the northeast of European Russia. Intraspecific genetic differentiation is most clearly manifested between G. uralensis Less. subsp. pinegensis (Perf.) Kamelin locally endemic to the north of Europe (Arkhangelsk oblast, locus classicus) the population of G. uralensis Less. subsp. uralensis on limestone outcrops along the Shchugor River, the Subpolar Urals. The cluster of Timan populations (on limestone outcrops along the Svetlaya, Pizhma, and Myla rivers) is autonomous and genetically heterogeneous. Genetic distances between model G. uralensis s.l. populations are correlated with geographic distances. The size and abundance of relict populations show a descending gradient in the forest zone, and parameters of their genetic diversity [1] and unbiased expected heterozygosity have been found to decrease along this gradient.  相似文献   

10.
The structure of genotypic diversity in eight populations of the clonal triploid (2n = 3x = 36) tulip Tulipa riparia inhabiting floodplain communities in the Southern Urals was studied. Analysis of nine polymorphic enzyme systems (ADH, IDH, SkDH, PGI, PGM, FDH, NADHdh, C-EST, GOT) was performed to identify clones. Both monoclonal (D = 0) and polyclonal populations with multiple genotypes from 3 to 12 (D from 0.73 to 0.91) were identified. The polyclonal populations had a high level of heterozygosity. Dispersal of propagules (bulbs) along rivers and even from one bank of a river to the opposite was detected. Some clones disperse along riverbanks to the distance of hundreds meters (up to four kilometres). At the same time, there is an effect of “isolated” or “closed” populations. Almost each sequentially arranged population in one river system have its own set of genotypes. Assessment of the state of the reproductive system components indicates presence of a rare sexual reproduction supporting genetic diversity of T. riparia.  相似文献   

11.
The effect of long-term exposure to natural excretions of the European polecat on the morphological parameters and hormonal status of adult male Campbell hamsters (Phodopus campbelli) and dwarf hamsters (Ph. sungorus) was studied. Exposure to volatile components of natural excreta of a potential predator did not have any significant effect on hamsters. The combined influence of volatile and nonvolatile components of the polecat’s excretions caused physiological stress in Ph. campbelli, while in Ph. sungorus, on the contrary, an increase in thymus weight and the plasma testosterone level was recorded.  相似文献   

12.
The composition and contents of secondary metabolites in Flavocetraria lichens from Eastern Siberia were analyzed using herbarium specimens. Based on the composition of identified metabolites, three F. cucullata chemotypes and two F. nivalis chemotypes were distinguished. Distinct geographic differentiation between the F. cucullata chemotypes was revealed, probably reflecting their adaptation to environmental conditions. The content of usnic acid in F. cucullata thalli was found to correlate with the latitude of growing region. This may be regarded as evidence for a protective role of this metabolite in lichens growing at high latitudes and exposed to excess solar irradiation during the polar day.  相似文献   

13.
Present study was carried out to determine pollinators’ diversity and their efficiency with modular approach; foraging behaviour, number of loose pollen adhered on their body and number of pollen deposited on the stigma. The observations explicitly indicate that Megachile spp., Xylocopa tenuiscopa, Amegilla zonata and Nomia sp. were true pollinators and out of these, Megachile spp. were key pollinators of pigeonpea. Among megachilids, Megachile lanata was the most efficient pollinator. Sufficient pollination meticulously accomplished in pigeonpea by true pollinators under this agro-ecological region.  相似文献   

14.
The accumulation of fluorine in the trunk wood and branches of Larix gmelinii growing on soils with a naturally increased fluoride content and of L. sibirica growing in a zone affected by atmospheric emissions from an aluminum plant has been studied. Based on results of in vivo and in vitro experiments, it is concluded that larch trees manifest individual differences in their response to fluorine.  相似文献   

15.
Basic climatic parameters (annual average air temperature and annual amount of precipitation) over 12–25 years have been analyzed with regard to their values corresponding to different levels of abundance in three species of forest voles: Clethrionomys glareolus (in 11 areas of the species range), Cl. rutilus, and Cl. rufocanus (in three areas each). The results show that the abundance of all these species correlates significantly with fluctuations of annual average temperature, with the correlation being negative in Cl. glareolus and Cl. rufocanus but positive in Cl. rutilus. In addition, the abundance of Cl. rufocanus shows a significant correlation with annual precipitation. Voles inhabiting different geographic regions may reach high abundance under different conditions. As for the species range as a whole, however, Cl. glareolus is more ecologically flexible than the other two voles. This species is also more warmth- and moisture-loving, while Cl. rufocanus is more cold-loving and xerophilous, with Cl. rutilus occupying an intermediate position between them. Clethrionomys rutilus is most temperature-dependent and stenothermic among them, whereas Cl. glareolus is indifferent to the factors studied.  相似文献   

16.
Specific ecological features of trees (Chosenia arbutifolia and Betula lanata) and shrubs (Pinus pumila and Duschekia fruticosa) at the northern limit of their distribution are compared. New biomorphological adaptations of these species under extreme conditions are described.  相似文献   

17.
This paper documents zootherapeutic practices in Northeast Brazil. It is primarily based on field surveys carried out in fishing villages located in the States of Maranhão and Paraíba, where dwellers provided information on snake species used as medicine, body parts used to prepare the remedies, and the illnesses to which the remedies were prescribed. The species used as medicinal drug and their respective families were: Crotalus durissus (rattlesnake), Bothrops leucurus (‘lance head’, a venomous snake), and Lachesis muta (bushmaster) of the family Crotalidae; and Boa constrictor (boa constrictor), Epicrates cenchria (‘salamanta’), and Eunectes murinus (anaconda) of the family (Boidae). These zootherapeutical resources were used for the cure of 14 illnesses. The most commonly cited species were Crotalus durissus (n=26) e Boa constrictor (n=6), Apparently, the medicinal use of snakes does not pose a threat for their population in the studied sites.  相似文献   

18.
The linear increment of Sphagnum fuscum and S. magellanicum in ombrotrophic mires of Western Siberia has been measured during two years over a transect about 2500 km long extending from forest–steppe to forest–tundra. Along the latitudinal gradient, the increment of both species has proved to be correlated with annual average air temperature and, in S. magellanicum, also with annual precipitation. The determinants of their growth differ between the southern, central, and northern parts of the study region. At the regional level, the annual and summer precipitation plays a more important role than the average air temperature. The increment of S. fuscum in the southern part is positively correlated with the amount of precipitation and negatively correlated with summer temperature, whereas the situation in the central part is inverse. In S. magellanicum, the linear increment is directly dependent on the annual average temperature and annual and summer precipitation in the south and on the annual and summer precipitation in the north of Western Siberia. The dynamics of linear growth of both species in bog pine forests during the growing season are similar: its rate is the highest in June, when the linear increment of S. fuscum and S. magellanicum amounts to 60 and 85% of the annual total, respectively.  相似文献   

19.
In this study we investigated the size-dependent reproductive pattern of Inula racemosa and I. royleana (Asteraceae) growing at different reaches in the environs of the Kashmir Himalaya. Size effects on reproductive pattern were evaluated by determining the size-dependency of flowering probability and reproductive effort. The results showed that the probability of flowering increased significantly with the size of the plant in all populations, indicating that individuals do not flower until they reach a threshold size and considerable between-site differences were found in the slope and the intercept of the regression between plant size and flower production. In I. racemosa, populations at high altitudes had significantly lower threshold sizes for reproduction and showed sharp increase in flowering probability with plant size, compared to other populations at lower altitudes. However, no pattern in size-dependent flower production was found relative to the altitude in I. royleana, as flower production at some sites, at high altitudes, increased more steeply with plant size than at other sites. For both taxa, reproductive effort decreased allometrically as adults grew, as can be interpreted from the allometric relationship between reproductive and vegetative biomass. Further studies are required to determine whether population differentiation in size-dependent reproductive pattern is maintained by selection.  相似文献   

20.
The amino acid spectrum of blood plasma in three bat species (Myotis dasycneme, Pipistrellus nathusii, Vespertilio murinus) inhabiting the Urals has been studied for the first time. The bats were trapped in the zone of their high abundance in Chelyabinsk oblast (2013–2014). Free amino acids were determined by liquid ion exchange chromatography (a total of 384 determinations). It has been shown that the plasma amino acid spectrum consists of 22 amino acids in subadult bats of all three species, but there are species-specific differences in their concentrations. The total amino-acid pool concentration in migratory P. nathusii and V. murinus exceeds that in resident M. dasycneme by factors of 2.9 and 1.8, respectively. Migratory species are characterized by a high concentration of plasma arginine: it is six times higher in V. murinus than in M. dasycneme, and in P. nathusii arginine accounts for 25.4% of the amino acid pool. The group of glucogenic amino acids is prevalent in the blood plasma of migratory species (75% in V. murinus and 79% in P. nathusii), while in M. dasycneme the total proportion of lysine, glycine, and glutamic acid is 2.3 times lower than in P. nathusii and 1.7 lower than in V. murinus (p < 0.05). These results provide evidence for significant differences in the contents of free blood plasma amino acids between migratory and resident bat species.  相似文献   

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