武陵山片区高质量景区空间分布格局及其影响因素

基于武陵山片区高质量景区POI数据,综合运用最邻近指数、核密度分析和空间叠加分析等方法,探析武陵山片区高质量景区空间分布格局及其影响因素.结果 显示:(1)武陵山片区高质量景区整体呈现集聚分布态势,在片区层面上,集中分布于湖北分片区和湖南分片区;在地市层面上,主要聚集于恩施州、怀化市、渝东南地区、湘西州、张家界市和铜仁市.(2)武陵山片区高质量景区分布密度的空间差异显著,湖北和湖南分片区表现出典型的"核心—边缘"结构,而贵州和重庆分片区核密度值自东向西梯度递减.(3)武陵山片区高质量景区空间分布格局受自然因素和人文因素影响显著,其中地形地貌、河流水系和空气质量既是重要的构景要素,也是高质量景区空间分布的重要内生动力;而区域经济、交通通达性、旅游发展能力和政府政策支持的外部调控作用明显.     

How Prey Density and Distribution Can Affect Predator Habitat Usage Pattern: a Case Study on Sand Cat (<Emphasis Type="Italic">Felis margarita</Emphasis>, Locke 1858) from Iran

Prey-predator relationships can affect habitat selection of the animals greatly. In the recent investigation we tried to test how rodents can affect nocturnal sand cat habitat usage pattern. Microhabitat affinities of sand cat and its den site selection were investigated in Sistan and Baluchistan Province from early 2013 to late 2015 in Semsor area. The data acquired from 29 presence plots of individuals were compared by paired non-used plots; the results indicated that the presence of Haloxylon ammodendron and relative density of rodents mainly affected Sand cat microhabitat selection. We also found that the species den site selection was mainly influenced by the presence of tall shrubs such as Haloxylon ammodendron and Tamarix sp. We concluded that the habitat selection pattern of sand cat in the study area could be significantly influenced by rodents’ microhabitat selection; however, such relationship may not be true in larger spatial scales like species home range.     

Caucasian Black Grouse (Tetrao mlokosiewiczi) breeding display sites selection in Arasbaran Region, East Azerbaijan, Iran

Micro-habitat characteristics of breeding display Sites (Leks) of Caucasian Black Grouse (Tetrao mlokosiewiczi) were studied in the mountains of Arasbaran Region, East Azerbaijan, from October 2006 to June 2008. We quantified micro-habitat characteristics around active and inactive Caucasian black grouse lek sites and random points in the 3 areas (Biosphere reserve, Kalan protected area (one of core zones of Arasbaran biosphere reserve) and unprotected areas)). Our objective was to compare micro-habitat characteristics among these sites. We also developed a logistic regression model to identify micro-habitat factors have important effect in the active lek sites. In the micro-habitat scale, we measured both biotic factors (canopy cover (%), height (cm) and frequency of vegetations) and abiotic (physical) factors (slope (%), altitude (m), aspect and etc.). Slope and altitude were different significantly between sampling sites (p = 0.05). Mean of slope in the active leks (= 57.9%) and inactive leks (= 52.0%) were higher than random sites (= 40.1%). The mean aspect differed between active leks ( $ \bar X $ = 284°, S.D = 54.1°) and random sites ( $ \bar X $ = 33°, S.D = 76.18°) (Watson’s U²-test, U _{0.05, 22, 27} ² = 0.717). Also, variance analysis (ANOVA) revealed that grasses and forbs cover, frequency of deciduous shrubs and forbs, canopy cover and frequency of deciduous woody plants > 12 cm diameter at breast height were different significantly between sampling sites. The best model for discriminating between active lek and random sites included rock-pavement cover (parameter estimate [B] = 0.286, SE = 0.219), canopy cover of grasses (parameter estimate [B] = 0.880, SE = 0.453), distance to the nearest tree (parameter estimate [B] = ?0.047, SE = 0.027).     

Distribution of naturally occurring radionuclides (U, Th) in Timahdit black shale (Morocco)

Attention has been focused recently on the use of Moroccan black oil shale as the raw material for production of a new type of adsorbent and its application to U and Th removal from contaminated wastewaters. The purpose of the present work is to provide a better understanding of the composition and structure of this shale and to determine its natural content in uranium and thorium. A black shale collected from Timahdit (Morocco) was analyzed by powder X-ray diffraction and SEM techniques. It was found that calcite, dolomite, quartz and clays constitute the main composition of the inorganic matrix. Pyrite crystals are also present. A selective leaching procedure, followed by radiochemical purification and alpha-counting, was performed to assess the distribution of naturally occurring radionuclides. Leaching results indicate that 238U, 235U, 234U, 232Th, 230Th and 228Th have multiple modes of occurrence in the shale. U is interpreted to have been concentrated under anaerobic conditions. An integrated isotopic approach showed the preferential mobilization of uranium carried by humic acids to carbonate and apatite phases. Th is partitioned between silicate minerals and pyrite.     

Application of Remote Sensing and GIS in the Management of Mangrove Forests Within and Adjacent to Kiunga Marine Protected Area, Lamu, Kenya

The status of mangroves within and adjacent to Kiunga Marine Protected Area (MPA) were assessed by means of aerial photographs and intensive ground truthing. Vegetation maps (1 : 25,000) were produced on GIS environment making it possible to store, retrieve and analyze various types of information very quickly. The maps together with the digitized information provide important tools to the management of mangroves of Kiunga MPA since various proposed treatments can now be entered and summarized thus providing useful overviews for planning, implementation and monitoring.The present inventory revealed that the existing mangrove forests within and adjacent to Kiunga MPA have a net standing volume of 2,354,004.85 m³ in 16,035.94 ha. There are eight species of mangrove trees, of which Rhizophora mucronata and Ceriops tagal are dominant. The standing volume ranges between 6.85 to 710.0 m³ ha^–1 for stem with diameter above 5.0 cm. The average volume of the entire study area was 145.88 m³ ha^–1, which corresponds to a stocking rate of 1736 stems per ha. Given its high potential productivity and regeneration, mangroves within and adjacent to Kiunga MPA have excellent prospects for sustainable exploitation.     

Distribution of uranium and radium isotopes in an aquifer of a semi-arid region (Manouba-Essijoumi, Northern Tunisia)

Groundwaters from the Sebkhet Essijoumi drainage basin, situated in northern Tunisia, West of the city of Tunis, were sampled and analyzed for uranium and radium isotopes. Low (234)U/(238)U activity ratios coupled with relatively high (228)Ra and (238)U concentrations were found in the Manouba plain phreatic aquifer, at the northern part of the basin, where remote sensing has indicated that this plain corresponds to the main humid zone of the area. Low (234)U/(238)U ratios probably reflected short residence time for waters in the Manouba plain, and high ratios longer residence time in the south, where water reaching the phreatic aquifer seems to have previously circulated in rocks constituting the southern hills. Assuming that, in the Manouba plain aquifer, the groundwater flows downstream from the Oued Lill pass area to the South-West of the Sebkha, the difference in the (228)Ra/(226)Ra activity ratio suggests that the residence time of water has been 2.8 years longer near the Sebkha than upstream.     

Distribution of (226)Ra-(210)Pb-(210)Po in marine biota and surface sediments of the Red Sea, Sudan

Activity concentration levels and ratios of (226)Ra, (210)Pb and (210)Po are presented in multicellular marine algae, molluscs, coral as well as in surface marine sediments collected from the shallower waters of the fringing reefs area extending towards north and south (Flamingo bay) of PortSudan harbour, Sudan. The analyses were performed adopting alpha-spectrometry, liquid scintillation and Cerenkov counting techniques. Surface sediments from this coastal region are poor in their radioactivity content in contrast to similar data reported from different coastal areas around the globe. There is surface enrichment of (210)Pb and (210)Po with respect to their progenitor (226)Ra as it is evident from the activity ratios of (210)Pb/(226)Ra (3.03+/-1.79) and (210)Po/(226)Ra (2.23+/-1.56). Among marine plants and animals investigated, the green algae species, Halimeda, and coral species, Favites, show substantial concentration of radium at 8.2Bq/kg and 21.9Bq/kg dry weight, respectively. Similarly, the highest concentration of (210)Po was met in Favites at 38.7Bq/kg followed by brown algae, Cystoseria sp., at 32.6Bq/kg. There is no variation seen among algal species for (210)Pb uptake, however, converse to radium and polonium, Favites (coral) was found to contain the minimum concentration of lead (3.88Bq/kg). In most species there is preferential accumulation of polonium over its parent radium as indicated by (210)Po:(226)Ra activity ratio with Cystoseria (brown algae) showing the highest value at 8.81. On the other hand, (210)Po:(210)Pb activity concentration ratio revealed that coral species Favites (9.97) and the brown algae Sargassum (1.85) have a greater tendency to accumulate (210)Po over (210)Pb, while in the rest of species; this ratio is less than unity.     

发达地区农户宅基地置换意愿多水平影响因素研究——来自苏州与常州的实证

已有农民宅基地置换意愿影响因素分析主要基于单一水平,忽略了影响因素的多尺度效应。对此,引入多水平回归模型,基于对地处经济发达地区的苏州和常州的17个村394个农户的调查,研究多水平影响因素对农民宅基地置换意愿的作用机理。结果显示:(1)苏州地区农户宅基地置换意愿较常州地区低,各村农户置换意愿存在显著差异,且这一差异中75.12%的份额由村庄差异造成;(2)农户层次的年龄、文化程度、家庭主要收入来源对农民宅基地置换意愿具有显著正向作用,家庭人数具有负向作用;(3)村级户均收入、环境水平对家庭主要收入来源影响置换意愿起着弱化作用,而村经济发展水平、到最近城镇的距离具有强化作用;村级因素解释了95.69%的主要收入来源与置换意愿间的相关关系。研究表明,村级因素通过改变农户层次因素的影响程度,进而导致了村级间农户置换意愿的差异。因此,需综合考虑农户及村级层次的因素,并从完善相关配套政策及保障体系、加大政策宣传力度、优化宅基地布局、完善公共服务设施、加大环境治理、提升农户增收能力等方面推动宅基地置换工作。     

城市滨江地区生态用地演变及驱动因素分析——以长江南京段为例

从中小尺度对城市滨江生态用地演变进行研究,可为制定生态用地开发与保护政策提供重要参考。基于2005、2009、2014和2018年土地利用数据,利用转移矩阵等方法分析了南京滨江1 km范围内生态用地演变特征,并从城乡用地冲突和政策有效性角度对这些变化进行探讨。结果表明:(1)耕地大面积减少导致滨江地区生态用地比重下降,由2005年的71.86%下降到2018年的65.54%,但是林草地等半自然生态用地的比重略有上升;(2)林地、内陆滩涂保留率较高,耕地、园地、水域等地类变化以数量净变化为主,而林草地以空间交换变化为主;(3)生态用地流失热点区主要位于中心城区与近郊区间的城乡过渡带,并临近产业园区,建成区扩张是其主要成因;(4)政策规划对滨江生态用地演变作用明显,沿江开发政策加剧了生态用地流失程度,而生态红线等规划对某些重要生态用地保护效果显著,土地利用规划在用地管理方面效果显著,但仍存在耕地、裸地、内陆滩涂被违规侵占现象,长江防洪堤对生态用地保护作用不显著。要使生态空间得以长期存在,不仅需要明晰的政策边界,还需要加快形成公众对生态景观的整体认知和基于生态用地功能目标的保护政策。     

Genotoxic effects of binary mixtures of xenoandrogens (tributyltin, triphenyltin) and a xenoestrogen (ethinylestradiol) in a partial life-cycle test with Zebrafish (Danio rerio)

A partial life-cycle test with the model fish Danio rerio was performed in order to evaluate the genotoxic potential of binary mixtures of xenoandrogenic (tributyltin--TBT; triphenyltin--TPT) and an estrogenic compound (ethinylestradiol--EE2). Five days post-fertilisation larvae were diet-exposed to environmental relevant concentrations of TBT and TPT (25 ng/g-100 ng/g), and water-exposed to ethinylestradiol (3.5 ng/L) for a four-month period; binary mixtures of TBT plus EE2 and TPT plus EE2 were run in parallel. The erythrocytic nuclear abnormalities (ENA) assay in circulating erythrocytes was used to evaluate genotoxicity in the end of the four-month exposure period. A significant increase (p<0.05, Kruskall-Wallis non-parametric ANOVA) in ENA frequency, in comparison with control animals, was observed in those animals exposed to TBT and TPT (the highest doses only), and to EE2 and the binary mixtures, although neither synergistic nor additive effects of the tested compounds were evident. Overall, the results clearly indicate that chronic exposure to low levels of TBT, TPT, EE2 and binary mixtures of TBT plus EE2 and TPT plus EE2 are genotoxic to zebrafish, which may suggest that wild fish populations may be under increased DNA damage in areas contaminated by these endocrine disrupting chemicals.     

Distribution of fallout radionuclides (7Be, 137Cs, 210Pb and 239,240Pu) in soils of Taiwan

Depth profiles and cumulative deposition of four fallout radionuclides (7Be, 137Cs, 210Pb and 239,240Pu) were determined in presumably undisturbed soils in Taiwan. Inventories of these radionuclides in different areas correlate significantly with each other (except 7Be) and with mean annual rainfall, providing a necessary condition for the development of soil erosion studies in Taiwan. However, the data show very large spatial variability between and within landscape units, reflecting the steep topographic and meteorological gradients in the island. Thus, the application of fallout radionuclides to study soil conservation in Taiwan is expected to be a demanding task; it will call for dense sampling even at undisturbed reference sites.     

Toxicities and tolerances of Cd, Cu, Pb and Zn in a primary producer (Isochrysis galbana) and in a primary consumer (Perna viridis)

Studies on toxicities and tolerances of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in the brown alga Isochrysis galbana and in the green-lipped mussel Perna viridis were conducted by short-term bioassays using endpoints growth production and mortality, respectively. The 5-day EC(50) and 24-h LC(50) of these heavy metals were determined in the brown alga and mussel, respectively. The EC(50) values calculated for the alga were 0.74 mg/l for Cd, 0.91 mg/l for Cu, 1.40 mg/l for Pb and 0.60 mg/l for Zn. The LC(50) values for the mussels were 1.53 mg/l for Cd, 0.25 mg/l for Cu, 4.12 mg/l for Pb and 3.20 mg/l for Zn. These LC(50) values were within the concentration ranges as reported by other authors who used P. viridis as the test organism. Based on these EC(50) and LC(50) values, the alga was most sensitive to Zn, followed by Cd, Cu and Pb while the mussel was most sensitive to Cu, followed by Cd, Zn and Pb. Differences in the trophic levels, metal handling strategies, biology and ecology of the primary producer (brown alga) and the primary consumer (mussel) are believed to be the plausible causes for the different toxicities and tolerances of the metals studied.     

Factors influencing ambient concentrations of (210)Pb and (7)Be over the city of Edinburgh (55.9 degrees N, 03.2 degrees W)

Concentrations of (210)Pb and (7)Be in air were continuously monitored, using a high-volume air sampler and a high-resolution gamma-ray spectrometer, during the period of July 2002 to June 2003 at the University of Edinburgh 55.9 degrees N, 03.2 degrees W. The time series of both radio-isotopes show seasonality, dependence on air-mass origin, residence time and precipitation. Surface air concentrations of (210)Pb and (7)Be ranged from 0.01 to 0.74 mBq m(-3) and 0.63-6.54 mBq m(-3), respectively. The measurements indicate that the average concentrations of both (210)Pb and (7)Be in surface air were 0.21+/-0.01 and 2.50+/-0.04 mBq m(-3), respectively; which agrees closely with the corresponding values reported for coastal air measurements in Europe.     

发达地区人口、土地与经济城镇化协调发展度研究

江苏省作为中国东部沿海经济发达地区省份的典型代表,正处于城镇化加速发展的关键时期。新时期的城镇化是一个融合人口、土地与经济的复杂系统,不能从单方面衡量城镇化发展水平。在归纳总结城镇化内涵的基础上,选择人口城镇化、土地城镇化和经济城镇化为切入点,从三个方面衡量江苏省的城镇化水平的变化过程,研究不同时空城市在人口、土地和产业三方面协调发展的状态。结果显示,1998-2009年12年间江苏省人口城镇化、土地城镇化和经济城镇化的发展都呈现上升趋势,但在不同阶段处于主导地位的城镇化驱动力量不同,协调发展度也处于上升状态,从衰退发展阶段(1998-2003)逐渐发展到过渡阶段(2004-2005),最后到达协调发展阶段(2006-2009);在空间分布上,以2009年为例,综合评价结果显示,江苏省的城镇化水平和协调发展度总体水平较高,但是也存在区域分异明显的特点。     

Habitat suitability and potential distribution of <Emphasis Type="Italic">Laudakia nupta</Emphasis> (De Filippi, 1843) (Sauria: Agamidae) in Iran

In the present study, Laudakia nupta were selected as a case study and were examined using the Maxent method to evaluate the potential distribution and most suitable areas. All occurrence records of the species have been gathered from literature and recent updated checklists of lizards of Iran. The final model of L. nupta showed a good performance (AUC = 0.962; SD = 0.011) indicating that the most suitable areas are situated in the western Zagros Mountains in Iran. The situation of the suitable areas in the western Zagros, while the remaining southeastern areas are of low suitability, is controversial and needs more investigation with different criteria such as molecular and other systematic methods. Precipitation of the wettest quarter is the most effective factor for the species presence and I can assume this importance is directly related to the growth of plant in the habitat as main source of food.     

Evaluation of education and water resource types on some wheat land features, using Fars Comprehensive Agricultural Database (case study; Pasargad, Iran)

Fars Comprehensive Agricultural Database was created to remove bottlenecks and constrains of province for decision makers in a way that leads to sustainable agriculture. Regarding Fars agricultural comprehensive information database, and the importance of wheat as the strategic commodity, this study was conducted in Ali-Abad-e-Kamin (Pasargad, Iran) to assess two most important managerial factors affecting other agricultural factors. Therefore, in this study, besides evaluating the effect of water resource on wheat yield and other traits, education impacts were analyzed and evaluated as well. Data were collected regarding cadastre land use information derived from satellite imagery combined with GIS potencies, and also a comprehensive questionnaire was completed to collect local field information. Results revealed that educational level has significant effect on crop yield, fields’ area and seed consumption rate and also effect of water resource showed significant difference for crop yield, fields’ area. Finally, interactive effect of water resource and educational level showed significant difference just for wheat yield. Also, as a result, higher education positively results in improved wheat yield, lands’ area and seed consumption rate. On the other hand, river as a type of sustainable water resource with karstic geological formations positively affected wheat yield, lands’ area and farms distance from village. Overall, transferring knowledge from relevant organization resulting in higher productivity seems to be necessary.     

Distribution and sources of (129)I in rivers of the Baltic region

The concentration of (129)I was measured in 54 river waters discharging into the Baltic Sea from Sweden, Finland, Estonia, Latvia, Lithuania, Poland and Germany. Sample collection was performed during a well-bracketed time interval (June-July 1999), thus allowing comparison of the rivers over a wide latitude range without the effect of long temporal spread. Although there is no direct input of anthropogenic (129)I in the watersheds, the concentration of the isotope is about two to three orders of magnitude higher than the expected pre-nuclear era natural values in the rivers of Finland and northern Sweden, and in the rivers of southern Sweden, Lithuania, Estonia, Latvia, Poland and Germany; the (129)I concentration may reach five orders of magnitude higher. Furthermore, there are significant correlations between the (129)I concentration and latitude and/or distance from the North Sea and between (129)I and Cl. These findings suggest seawater as a main source of (129)I to the rivers through atmospheric transport. Of the many chemical parameters investigated, the pH may account for some of the variability in (129)I concentrations of the rivers. The contribution from nuclear weapon tests and the Chernobyl accident to the riverine (129)I is insignificant compared to the releases from the nuclear fuel reprocessing facilities. The total flux of (129)I by rivers to the Baltic Sea and related basins represents minor amounts of the isotope pool in these marine waters. External radioactivity hazards from (129)I are considered to be negligible in the Baltic region. However, as the main (129)I intake to the human body is likely through water, due to the large amount of daily water consumption, more concern should be given to internal radioactivity hazard that may be associated with the isotope's localized elevated concentration in the human organs.     

Distribution and correlation of the natural radionuclides in a coal mine of the West Macedonia Lignite Center (Greece)

The distribution and correlation of six natural nuclides in the West Macedonia Lignite Center, Northern Greece were studied. Fifty-five samples of lignite, aged from 1.8 to 5 million years, and corresponding steriles, beds of marls, clays and sands alternating with the lignite, were collected perpendicular to the mine benches and measured spectroscopically. The mean concentrations of (238)U and (226)Ra in lignites were found to be higher than that in steriles since these nuclides are associated with the organic material of lignite, whereas (238)U/(226)Ra equilibrium was not observed in either lignites or steriles. Finally, the ratio (226)Ra/(228)Ra in lignites was approximately double of that in steriles, confirming the affinity of the (238)U series with the coal matrix in contrast to the (232)Th series. No correlation was found between radionuclide concentrations and the depth of the sample, nor with the ash content of lignite.     

(90)Sr, (210)Po and (210)Pb in lichen and reindeer in Norway

Concentrations of (90)Sr, (210)Po and (210)Pb in lichen and reindeer were studied in central (?stre Namdal) and southern Norway (V?g?) during 2000-2003. The study focussed on potential differences in concentrations of these nuclides in reindeer of different ages. Concentrations of (90)Sr in bones of approximately 10 year old adult females were about 40% higher than those in calves' antlers ((90)Sr concentrations in antlers and bones of calves are similar), while the available data from V?g? suggest that (90)Sr concentrations in reindeer calves decreased with an effective ecological half-time of 9.03+/-0.06 years during 1988-2002. Furthermore, (90)Sr concentrations were 50-80% higher in bone of reindeer of a similar age from V?g? compared to those from ?stre Namdal. Concentrations of (210)Po and (210)Pb in muscle and liver tissues were comparable to those reported for reindeer in other Nordic areas, with no significant difference in (210)Po and (210)Pb concentrations between adults and calves or between reindeer from the two different study areas.