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1.
Studies of nest-site selection and reproduction are essential for bird species assessment and conservation. We compared breeding habitats and random sites within a secondary cavity-nesting bird, Yellowrumped Flycatcher (Ficedula zanthopygia), in a 5-year studying period in northeast China. We also modeled the effects of factors on daily nest survival rates. The flycatcher nest cavities were mostly located in tree trunks, with only 15% found in limbs. They often located their nests in east and south direction (45°–180°) with dense canopy cover surrounding the nest trees. Yellow-rumped Flycatcher nest-site selection appears to be nonrandom, such that they select nest sites with higher tree density and higher canopy closure. Yellowrumped Flycatcher daily nest survival rate was 0.9731 ± 0.007. Daily nest survival increased with increasing percent cover of canopy closure and decreased with the distance closing to the edges. The causes for nest failure were mainly nest usurpation by other secondary cavity-nesters. Predation rate and the competition for cavities with other secondary cavity-nesters may constrain the ability of Yellow-rumped Flycatchers to optimize nest nest-site selection.  相似文献   

2.
In this paper, we assess the associations between self-reported happiness, measured using the Gallup Healthways Well-Being Index (2012), and four US city sustainability indices: the Green City Index (2011), Our Green Cities (2012), Popular Science US City Rankings (2008) and the SustainLane US Green City Rankings (2007). Based on the examination of nonparametric, rank-based correlations, we found positive associations between sustainable development and happiness on all scales and statistically significant correlations for two of the four SD indices. Results support previous research, emphasize the value of explicit consideration of happiness when measuring urban sustainability and highlight the need for future research that assesses the influence of specific subsystems of urban development on self-reported happiness.  相似文献   

3.
The effects of snow regimes (including the depth and duration of snow cover) on soil N dynamics and microbial activity in situ were explored in the alpine belt of the eastern Tibetan Plateau. Deeper snow-cover reduced NH 4 + -N content, microbial biomass carbon and nitrogen, fungi count, and enzyme activities, whereas did not change net N mineralization. No differences in N pools in the soil, microbial biomass, microbial counts, and enzyme activity were found under the different duration of snow cover, showing that accumulation and release in soil N pools did not be significantly changed by earlier continuous snow cover.  相似文献   

4.
Vandana Shiva has argued that the world is experiencing the triple crises of climate change, peak oil and increasing global food insecurity (Shiva 2008). A Green Economy, which focuses on a “low carbon, resource efficient and socially inclusive economy” (UNEP 2011, 16), has been viewed in some quarters as a way to begin combating the triple crises. In Aotearoa New Zealand, some of the local indigenous peoples Maori are looking at green opportunities, primarily in renewable energy production. Some scholars suggest, however, that the Green Economy should be combined with a Blue Economy. The Blue Economy, as explained by Gunter Pauli 2010, is one which focuses on nature and encourages companies and entrepreneurs to mimic nature in their processes and in the creation of their products. In this article, I suggest that considering a Blue Economy through the lens of a Maori worldview allows us to explore in another way the questions that the Blue Economy raises.  相似文献   

5.
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   

6.
This paper considers three questions concerning a low-carbon society. The first is the implication of a 50% reduction in greenhouse gases (GHGs) by 2050. In the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, released in 2007 (IPCC 2007b; http://www.gtp89.dial.pipex.com/chpt.htm), the suggested limit of increase in average worldwide temperatures is 2–3°C above the current level, but is this consistent with a 50% reduction by 2050? Second, when a 50% reduction in global emissions is envisioned, what is the level of reduction needed in Japan? Should the 50% reduction be uniform for advanced industrial countries and developing countries, or differentiated based on a country’s emissions? Third, how feasible are emission reduction targets in Japan? Even if the emission reduction target set for each country takes into account climate change impact and equity, whether the target is technically, or socially and economically, acceptable is another matter.  相似文献   

7.
Massanjore reservoir (area ~67 km2) located 84 km downstream from the most distant upstream source capacitates 620,000,000 m3 of water, and regulated flow characters are highly responsible for dam downstream alteration of hydrological, sedimentological and geomorphological characteristics of Mayurakshi River. In dam after condition, monsoon water level (mean water level during monsoon months) and pre-monsoon water level (mean water level during pre-monsoon months, i.e., March–May) have attenuated about 0.56 and 0.32 m, respectively. Maximum duration of high flow period during monsoon has reduced up to 16.5 %; coefficient of variation of diurnal fluctuation of water level during monsoon has increased from 31 to 47 %. Suspended sediment load in Mayurakshi River is reduced to 34 % in dam after period as recorded at Narayanpur gauge station. Average suspended sediment load has decreased even after Tilpara barrage construction from 4.960 to 4.350 mg/L. Average suspended sediment load is 7.875 mg/L in the sites of dam upstream course, and this average is only 4.46 mg/L in different sites of dam downstream course. Volume of discharge has decreased up to 11.3 % during monsoon time in dam after condition. Such reduction in discharge volume in turn has reduced about 24.6 % bed load-carrying capacity. As a result, huge deposition within channel invigorated channel bed aggradations (average 73.6 cm up to Saspara, site 14 at Fig. 1) in dam after condition. Narrowing of active channel, coarsening of channel bed materials, lowering of lateral stability, accelerating rise of braiding index, mixed response of the channel adjustment of the tributaries to local scale positive or negative base level change due to river bed aggradations and degradation, etc. signify the morphological alteration of dam downstream course.
Fig. 1 Mayurakshi River basin indicating Massanjore Dam, Tilpara barrage and sample working sites
  相似文献   

8.
Recent Government announcements have implied that wind power will play a major part in providing energy for the UK (BBC 2007 BBC. 2007. Wind ‘could power all UK homes’ [online], British Broadcasting Corporation. Available from: http://news.bbc.co.uk/1/hi/uk_politics/7135930.stm [Accessed 20 January 2008] [Google Scholar]). However, there is much concern that wind farms can have a significant impact on flying fauna (bats and birds) using the area, particularly at night. As part of an Environmental Impact Assessment, thorough appropriate surveys are necessary for quantifying and minimising any risk wind farms may cause flying fauna. Manual surveys that are commonly used are not always cost‐effective, efficient or practical. Remote systems based on motion detection are increasingly being used to monitor wildlife.

Fast‐moving airborne targets such as aeroplanes can falsely trigger motion‐detection based remote systems. As birds and bats repetitively flap their wings, this oscillating motion can be used to distinguish them from other airborne targets. Time periods between wing oscillations are not always constant, and hence the motion is not periodic. A method to detect cyclic motion based on similarity matrices is proposed, and synthetic and real data are used.  相似文献   

9.
This paper aims at identifying the link between significant rainfall decreases (1950–2000) in the Mediterranean basin and the atmospheric circulation at the 500 hPa level. The months and seasons of the subregions with significant rainfall decrease during this period have been identified previously (Norrant and Douguédroit, Theor Appl Climatol 83(1–4):89–106, 2006): October in the Mediterranean Iberia, March in the Atlantic Iberia, January and winter in Greece, and winter in the Near East. Canonical Correlation Analyses based on the monthly and daily data records from 62 rainfall stations and 138 grid points at the 500 hPa level over a Euro-Atlantic window were first calculated to define the TeleConnection Patterns explaining significant regional rainfall decreases. Then, 500 hPa level weather types (ZWTs) of the rainy days with important or little rainfall associated with each Teleconnection Pattern were identified in each subregion. Rainfall-causing disturbances from the Atlantic reach Iberia directly; some of them are regenerated if they reach the Mediterranean. Other disturbances are generated locally near Greece and the Near East (Meteorological Office in Weather in the Mediterranean I: general meteorology, Her Majesty’s Stationery Office, London, 1962). The relationship between significant rainfall decreases and the corresponding 500 hPa level appears to be a nonlinear phenomenon. In all of the studied subregions, a break during the 1970s separates two subperiods differing significantly from each other. Rainfall decrease is due to the higher frequency of important rainfall ZWTs over low rainfall ZWTs, during the first period, which the opposite is true during the second period. Such an inversion could be partially linked with the prevailing North Atlantic Oscillation-positive phase during the last quarter of the twentieth century.  相似文献   

10.
In 2010, the global burden of foodborne diseases was 33 million Disability-adjusted life years, and 40 % of this burden was for children under 5 years old (Havelaar et al. 2015). Our study site was informal public markets within Mzuzu, Malawi, visited between September and December 2015, during the dry season. From these markets, fresh vegetables, leafy greens (n = 85), tomato (n = 85), and green pepper (n = 35) were analyzed for Escherichia coli. The prevalence of E. coli was highest on leafy greens; it was found in 74 (87 %) of the 85 samples. The prevalence of E. coli in green peppers was found in 2 (6 %) of the 35 samples. The prevalence of E. coli was lowest on tomatoes; it was found in only 1 (1 %) of the 85 samples. The lack of adequate water and sanitation infrastructure in market areas may be contributing to the bacteriological contamination of fresh produce. Providing venders with free access to market area toilets containing hand-washing facilities with soap and wash water with a chlorine solution may reduce bacterial contamination of fresh produce. Universal and sustainable access to water and sanitation services must include informal public market areas to reduce diarrheal diseases transmitted through food within Sub-Saharan Africa countries.  相似文献   

11.
In spite of broad and positive expectations, payments for ecosystem services (PES) can bring about unexpected and negative consequences, especially in terms of their impacts on the well-being of local communities dependent on ecosystems. Based on numerous observations of recurring problems with PES, we put forward an ecosystem service curse hypothesis (Kronenberg and Hubacek in Ecol Soc 18:art.10. doi: 10.5751/ES-05240-180110, 2013), that points to counterintuitive negative development outcomes for countries and regions rich in ecosystem services. The social and economic problems that we have been able to depict in many PES schemes reflect the persistence of maladaptive states in pursuit of sustainability. Instead of providing an opportunity to break out of poverty, these problems reflect entrapment, which is most often related to poor quality of institutions. Here we highlight the linkages between the ecosystem service curse hypothesis and the dynamic system stability landscapes discussed in this special issue. Our article consists of three parts in which we: (1) present the original ecosystem service curse hypothesis; (2) link this hypothesis to the broader discussions relevant to sustainability science; and (3) highlight the context of traps on which this special feature focuses.  相似文献   

12.
13.
Wildfire frequency, relative area burned, and fire return intervals (FRI) have been studied in larchdominated forests along the transect from the southern (45° N) to the northern (73° N) distribution limits of larch stands based on analysis of satellite imagery (NOAA/AVHRR, Terra/MODIS; 1996–2015) and collection of tree cross cuts with fire scars. A significant increasing trend in fire extent (R2 = 0.50, p < 0.05) has been revealed. Histograms of fire extent and frequency are bimodal in the southern and middle taiga (with peaks in spring–summer and late summer–autumn periods) but become unimodal toward the north (>55° N). The length of FRI increases from 80 years at 62° N to ~200 years at the Arctic Circle and reaches ~300 years near the northern limit of larch stands, showing a significant inverse correlation with the length of fire season (r =–0.69). In turn, the length of fire season, area burned and FRI are closely correlated with latitudinal variation in solar irradiance (r = 0.97, 0.81, and –0.95, respectively).  相似文献   

14.
Modeling the distribution patterns of species is a generally efficient tool to assess their ecological characteristics. In this study, we compared ecological niche factor analysis (ENFA) and maximum entropy (Maxent) techniques to predict the most suitable distribution range of Rana macrocnemis. The Maxent model predicted potential suitable habitats for R. macrocnemis with high success rates (AUC Training data = 0.877 ± 0.039). According to the map constructed, three important variables had high contribution to species presence: temperature (50.4%), land cover (24.6%) and elevation (14.4%) variables. The ENFA results were relatively similar to Maxent jackknife analysis. The results implied that R. macrocnemis prefers grassland and needle leaf deciduous forest with high elevations, and low temperature.  相似文献   

15.
Magnitudes of land cover changes nowadays can be assessed properly, but their driving forces are subject to many discussions. Next to the accepted role of human influence, the impact of natural climate variability is often neglected. In this paper, the impact of rainfall variability on land cover changes (LCC) is investigated for the western escarpment of the Raya Graben along the northern Ethiopian Rift Valley. First, LCC between 2000 and 2014 were analysed at specific time steps using Landsat imagery. Based on the obtained LCC maps, the link was set with rainfall variability, obtained by means of the satellite-derived rainfall estimates (RFEs) from NOAA-CPC. After a correction by the incorporation of local meteorological station data, these estimates prove to be good estimators for the actual amount of precipitation (ρ RFE1.0 = 0.85, p = 0.00, n = 126; ρ RFE2.0 = 0.76, p = 0.00, n = 934). By performing several linear regression analyses, a significant positive relationship between the precipitation parameter DIFF 5Y (i.e. the at-RFE pixel scale difference in five-year average annual precipitation for the two periods preceding the land cover maps) and the changes in the woody vegetation cover was found (standardised regression coefficient β = 0.23, p = 0.02, n = 108). Despite the dominance of direct human impact, further greening of the study area can be expected for the future concomitantly to a wetter climate, if all other factors remain constant.  相似文献   

16.
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.
19.
Total soil available nitrogen concentrations (NO–3 + NH 4 + ) were determined underneath plants of the more-competitive Poa ligularis, mid-competitive Nassella tenuis and the less-competitive Amelichloa ambigua exposed to various combinations of controlled burning and defoliation treatments. Defoliations were at the vegetative (V), internode elongation (E) or both developmental morphology stages (V + E) during two years after burning in northeastern Patagonia, Argentina. Hypotheses were that (1) concentrations of total soil available nitrogen after burning are greater underneath burned than unburned plants. With time, these differences, however, will gradually disappear; (2) greater total soil available nitrogen concentrations are underneath plants of the more- than less-competitive perennial grasses; and (3) total soil available nitrogen is similar or lower underneath plants defoliated at the various developmental morphology stages in all three study species than on untreated controls at the end of the study. Concentration of total soil available nitrogen increased 35% (p < 0.05) on average after the first six months from burning in comparison to control plants. However, these differences disappeared (p > 0.05) towards the end of the first study year. Total soil available nitrogen concentrations were at least 10% lower underneath the less competitive N. tenuis and A. ambigua than the more competitive P. ligularis on average for all treatments, although differences were not significant (p > 0.05) most of the times. Defoliation had practically no effect on the concentration of total soil available nitrogen. Rather than any treatment effect, total soil nitrogen concentrations were determined by their temporal dynamics in the control and after the experimental fire treatments.  相似文献   

20.
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   

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