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1.
Current international discussions on the increasingly critical levels of carbon emissions from the transportation sector commonly attribute the causality chain to urban sprawl growth–private car use–carbon emission. An often assumed development context of this causality chain is that common of developed country urbanization. However, in the particular context of developing country urbanization, urban sprawl and associated workplace–home distanciation may lead to more intensive use by the urban workforce of public mass transportation system, instead of higher dependence on private vehicle travel. Thus, the source of the rise in carbon emission may actually be the public transportation system. Utilizing mixed methods, combining quantitative (origin–destination matrices) and qualitative data gathering and analysis, the authors present a case study in Metro Manila which has been experiencing sprawl and increasing costs and unaffordability of land and housing in the workforce’s vicinity of employment. This, in turn, causes greater distances of daily travel between home and workplace using public transportation system. When the latter is characterized by fuel-inefficient small vehicles with second-hand engines, higher carbon emission results. We argue that the convergence of multiple interacting factors such as urban sprawl, lack of affordability of housing near the centres of employment, high dependence of commuters on public transports, longer distance travel by commuters, and low fuel efficiency of the public utility vehicles primarily causes the increase in CO2 emission from the transport sector. Implications of this case to policy scoping of immediate and long-term state responses for carbon emission mitigation in transportation sector are discussed.  相似文献   

2.
Water samples from zones with different levels of anthropogenic pollution in Peter the Great Bay, the Sea of Japan, were subjected to biotesting on the microalga Dunaliella salina. A distinct inhibitory effect on microalgal cultures was revealed in tests of water from Amur Bay. Water samples from stations in the Tumannaya River mouth and off Frugelm Island (in the southwestern part of Peter the Great Bay) and from Gaidamak Bight (Vostok Bay) had little effect on D. salina growth.  相似文献   

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The gyrfalcon in the Yamal Peninsula nests mostly on trees. The average brood size in this species decreased from 3.1 nestlings per active nest (n = 28) between 1973 and 1989 to 2.2 (n = 22) between 1998 and 2008. This decrease is probably explained by switching to the habit of using mostly smaller nests (built by the rough-legged buzzard, raven, or hooded crow) instead of large nests built by the white-tailed eagle. The survival rate of gyrfalcon nestlings in smaller nests is considerably lower: the average brood size is only 1.6 (n = 12), compared to 2.5 (n = 20) in medium-sized and 3.0 (n = 34) in large nests. The possible role of increase in snow cover density caused by climate warming in making large nests less accessible to the gyrfalcon is discussed.  相似文献   

5.
The distribution pattern of the gastropod Bradybaena fruticum has been studied in a forest-steppe landscape. Analysis of the frequencies of polymorphic biochemical and conchological characters has yielded preliminary results on the characteristics of the species population structure whose formation was determined by a set of natural and anthropogenic factors.Translated from Ekologiya, No. 1, 2005, pp. 39–47.Original Russian Text Copyright © 2005 by Snegin.  相似文献   

6.
A comparative study on the lipid composition of the liver and muscles has been performed in daubed shanny caught in summer (July) in Arctic waters at three different sites (biotopes) along the north-western coast of Spitsbergen. In marine organisms living at high latitudes, lipids play an especially important role, primarily as reserve substances and as a factor influencing adaptation to severe environmental conditions. Since the ecology of daubed shanny is poorly known, the data obtained may be considered novel.  相似文献   

7.
Data on the parameters of migration of two land snails of the genus Xeropicta are presented. In relatively homogeneous habitats, the locomotor activity of these mollusks is relatively high: they can travel for up to 300 cm per day, with neither the phenotype nor size of the shell having any significant influence on the level of dispersal. The snails prefer to travel westward and southward, but the distances covered by individuals moving in different directions are similar. No connection between the directions or distances of movement on two successive days has been observed.  相似文献   

8.
Only two river basins in which the European pearl mussel has survived to date are known in Arkhangelsk oblast. These are the Solza and Kozha basins. The northeastern boundary of the European range of this species passes along the watershed between the basins of the Solza and the Shirshema (the Onega Peninsula) and then along the Onega-Northern Dvina watershed. The population density and the proportion of juveniles widely vary in different parts of the Solza Basin, and, therefore, the previously conclusion concerning the ageing of the population in the Kazanka River (Bolotov and Semushin, 2003) applies only to certain parts of this river. The highest density of the pearl mussel in the Solza Basin is 68 ind./m2. Fish cultivation contributes to the conservation of this pearl mussel population, as the release of Atlantic salmon juveniles ensures reproduction of the mollusk under conditions of regulated river flow.  相似文献   

9.
Although the coastal salt marshes of Arabian Gulf have been altered extensively by human development activities, there is a paucity of data describing changes in the distribution and abundance of native coastal plant communities. The main objectives of this study are to determine vegetation condition, size structure, and conservation status of Nitraria retusa, a medicinal and salt-tolerant shrub, in disturbed and non-disturbed coastal salt marshes of Kuwait. Size measurements of Nitraria shrubs and nabkas, which are mounds of sediment developed around shrubs, were carried out in 50 quadrats (20 × 20 m2), randomly selected inside and outside Sabah Al-Ahmad Natural Reserve. Species richness and soil properties of nabkas and interspaces, the open areas between the nabkas, were also measured. The results revealed that nabkas of Nitraria in non-disturbed sites are more stable and rich in plant diversity than those in disturbed sites. Mean height and mean canopy diameter of Nitraria shrubs, total plant cover, and species richness are significantly higher in non-disturbed sites than disturbed sites, which indicate the positive influences of conservation for long term on vegetation structure and species richness. The results of soil analyses indicate the important role of nabkas in providing refuges for plant life and species diversity. The present study indicates that more than 50 % of the N. retusa community has been lost during the last few decades. Therefore, N. retusa should be considered an endangered species in Kuwait. The reduction in vegetation cover, a decline in species richness, and the overall degradation of salt marshes are attributed to human development activities along the coast of Kuwait. Effective conservation actions for threatened species in degraded coastal salt marshes of this region include establishment of protective enclosures, prohibitions on development that adversely affects native plant communities, and the planting native salt-tolerant shrubs to facilitate regeneration.  相似文献   

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The needles of juniper growing in spruce and birch forests of the Khibiny Mountains have been analyzed to evaluate the pattern of changes in their chemical composition (ADF, lignin, cellulose, lignin/cellulose, lipids, phenolic compounds, proanthocyanidins, flavonoids, N, C, and also Ca, Mg, K, Mn, Zn, P, S, Al, and Fe). It has been shown that the concentrations of lignin, lipids, phenolic compounds, Ca, Al, and Fe in the needles increase with age, while those of flavonoids, soluble and bound proanthocyanidins, N, P, K, Mg, Zn, and Mn decrease. The needles of juniper from spruce and birch forests differ in the contents of nutrient elements, which is explained by differences in the composition of soils. The contents of lignin, cellulose, and lipids in aging needles are lower in birch forests than in spruce forests.  相似文献   

12.
Diet, food preferences and main ecophysiological characteristics such like energy requirements and thermoregulation characteristics of Mus spicilegus spicilegus (Petenyi, 1882) were studied. The most preferred foods for the mice were seeds of weed species that composed more than 85% of their diet. The results of food selection experiments shows that the total daily consumption by mice is 2.77 ± 0.76 g/animal/day or 5.5 kJ/g/day or 84.9 kJ/animal/day. From the total daily energy consumption 16.4% go back to nature in the form of feces and urine and the rest 83.6% animals utilized for assimilation. The results of the temperature preferences for Mus s. spicilegus shows preferred temperature zone from around 26 to 36°C where mice spent about 72% of the experimental time. The lowest value of oxygen consumption for resting metabolism rate (RMR) was registered at 30°C–3.20 ± 0.71 cm3 O2/g/h. It is possible to consider that the thermoneutral zone is around these temperature values. The obtained results give reason to conclude that from an ecophysiologycal point of view the climate in the south boundary of distribution provides optimal conditions for species development. The main cause for population decreasing probably is the loss of open habitats including natural steppe grasslands.  相似文献   

13.
Future climate change may lead to a substantial loss of biodiversity, particularly affecting mountain regions, including the Alps. Range-size reduction in high mountain plant species is predicted to be more pronounced for endemic species. Investigating the broad temporal spectrum of range shifts is important for the conservation of biodiversity, since learning how species responded to climate change in the past provides useful insights on how they might react to warming trends in the present and future. Using species distribution models and an ensemble forecasting approach, we explored how the distribution of Berardia subacaulis, a monospecific genus endemic of the south-west Alps, may be affected by past and future projected climate change. During the last interglacial, the habitat suitability of Berardia was lower than present and a progressive increase was observed from the last glacial maximum until now. In the future, Berardia appears to lose more than 80 % of its range, becoming endangered by 2050. Our results suggest that Berardia probably survived past warmer periods in situ, expanding its distributional range during cooler periods. The severe future range contraction predicted for Berardia reflects similar results for other endemic species. As Berardia represents an interesting model species to evaluate the effects of climate warming on range size and shifts, demographic and precise range monitoring may be undertaken on this species.  相似文献   

14.
Turions of Potamogeton crispus were planted in several turbid waters. Some parameters of growth, reproduction and chlorophyll fluorescence were measured. The results were as follows: (1) Sprouting rates in all groups reached to 100.0% on the 17th day. (2) The parameters of the growth (stem and leaf) and chlorophyll fluorescence (ΦPSII, qP and qN) in 120 and 150NTU waters were inhibited heavily 60 days later, and their survival time was only 140 days. However, the plants in 30 to 90NTU waters could grow near water surface, their survival time was about 190 days. (3) After 150 days, the saturating irradiance intensity and rETRmax of the leaves in 30 to 90NTU waters markedly decreased with an increase in the amount of attached silts, and the number and fresh mass of turions (propagula) in 60 and 90NTU waters were significantly lower than the control. In summary, P. crispus in 0.7-metre-deep turbid water with suspended silts (not more than 90NTU) could sprout and grow normally, and produce the turions.  相似文献   

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The dynamics of lipid and fatty acid composition of the muscles (flesh) and lipid sac in L. maculatus early life stages of different age collected in Kongsfjorden (Svalbard, Norway), in winter, during the polar night was studied. We showed that the total lipid content in the muscles increases on account of energetic triacylglycerols derived from the lipid sac, which is resorbed in juveniles as they switch to a demersal mode of life. The fatty acid spectrum directly reflects age-dependent and seasonal features of L. maculatus early life stages. The results of the study elucidate the specific role of lipids and fatty acids in the ecological and biochemical mechanisms related to ontogenic development of fish from the family Stichaeidae, particularly arctic-boreal L. maculatus, which assumed to become increasingly frequent in the Spitsbergen water area. They are important for understanding the ability of organisms to maintain and preserve the functional stability of ecosystems as a whole, especially under conditions of climate change in the Arctic.  相似文献   

18.
The diet structure of Asian badgers (Meles leucurus Hodgson, 1847) on Bol’shoi Chukhtinskii Island (Samarovskii Chugas Nature Park, Khanty-Mansi Autonomous Area) was studied by means of coprological analysis. Ten diet components were identified, including Siberian stone pine seeds (pine nuts), berries, earthworms, larval and adult insects, fishes, amphibians, reptiles, and mammals. The proportion of pine nuts was especially large. Seasonal fluctuations in the occurrence frequency and abundance of different foods were insignificant, but some of them were found to markedly vary between years.  相似文献   

19.
Demonstrative imitations in the defensive behavior of grass snakes (Natrix natrix) captured in the Galich’ya Gora Reserve (70 ind.) and Kulikovskii Forestry (13 ind.), Lipetsk oblast, have been analyzed using statistical methods. The results suggest that grass snakes can play dead and imitate a venomous snake independently of their sex, age, and experience in receiving injuries. At the same time, there is evidence that such an ability is a hereditary trait subject to natural selection.  相似文献   

20.
Annual cycle phenomena taking place in the nesting part of the range, such as dates of migration and breeding and molting pattern, have been studied in the wood warbler in northwestern Russia, at the boundary of its nesting range. The results provide evidence that the annual cycle of long-distance migrant birds living at the boundary of their nesting range has certain specific features.  相似文献   

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