基于生态足迹法的区域水资源生态承载力计算与评价——以珠海市为例

研究了人类社会对水资源的消耗、对自然生态环境的影响以及该影响的量化方法和量化指标,将生态足迹法引入区域水资源承载力系统,构建珠海市水资源生态承载力计算模型,分析计算水资源供给对区域经济社会发展的生态承载力,并对该地区的水资源生态承载力进行生态盈亏和敏感性评价.结果表明,总体上珠海市水资源系统呈现生态亏损,亏损率为37%,水资源生态承载呈现超载现象,珠海市城市化进程中流动人口增长对区域水资源的生态承载压力较大.研究结果还表明,将生态足迹模型运用到地区水资源承载力中具有较高的可信度,对地方尺度具有适用性.     

城市水资源合理利用分析与水资源承载力研究—以本溪市为例

本文以辽宁省重工业城市本溪市为例，运用指数评价模型，进行城市工业用水变化情况分析；同时采用系统动力学模型，预测城市水资源系统发展趋势。在此基础上，探讨水资源承载力的定量表示，提出可比较的区域不同策略的水资源承载力，从而为制定水资源的经济发展决策提供理论依据。     

基于目标规划模型的大连市水资源承载力分析

结合“大大连”建设的规划和“十五”及2010年远景规划,选取了人口、国内生产总值、公共绿地面积三个决策变量建立目标规划模型,采取3种方案对大连市水资源承载力进行预测,通过对预测结果的分析并结合水资源承载力的特点提出增强水资源承载力的方案:以可持续发展的观点来设计城市发展规划;调整和改造产业结构;改变城市绿化结构;兴修水利,发展节水技术达到水资源可持续利用。     

规划环境影响评价中的水资源承载力分析

应用系统动力学原理构建了规划环评中水资源承载力的理论模型;并在吸收PSR（Pressure-State-Response）和DSR（Driving-State-Response）模型分析方法基础上,采用＂目标-准则（系统）-指标＂的框架模式,构建了规划环评中水资源承载力的指标体系,并提出了计算模型,最后将一整套技术程序及方法应用于广州市南沙区发展规划环境影响评价中水资源承载力分析,验证其实用性及可行性,最终为决策者调整及优化规划方案提供强有力的科学依据。     

粮食水资源利用效率及影响因素分析:基于中国省际面板数据的实证研究

运用超效率松弛变量(SBM)模型探究2008—2017年中国粮食水资源利用综合效率、纯技术效率和规模效率的时间变化和空间分布,并采用Tobit模型分析自然环境和生产灌溉措施对用水效率的影响。结果表明,中国粮食水资源利用效率尚有很大的提升空间,综合效率和纯技术效率均呈倒"U"型趋势,而规模效率则呈先上升后稳定的趋势。空间分布方面,规模效率呈现出沿海地区高于内陆地区的特征;北部沿海、东北和长江中游粮食主产区水资源利用综合效率较低主要是由于纯技术效率较低所致,黄河中游和西南主产区综合效率较低主要是由于规模效率较低所致。进一步的影响因素分析表明,有效灌溉比例和育种技术发展均对3种效率产生正向影响,农村水源建设则对3种效率具有负向影响;此外,灾害程度对综合效率和规模效率产生负向影响。基于以上结论,对粮食水资源管理政策的实施提出了针对性建议。     

基于ARIMA模型的辽河流域生态足迹动态模拟与预测

将能值与生态足迹理论相结合,引入能量折算系数,通过能值密度构建能值-生态足迹模型,并应用此模型对辽河流域2001—2010年生态承载力和生态足迹进行计算。生态承载力计算主要是自然生态承载力和本地产品产出承载力,其中自然生态承载力主要考虑可更新资源的承载力,本地产品产出承载力主要包括生物资源产出承载力和工业产品产出承载力。生态足迹的计算主要包括消费足迹和污染足迹,消费足迹主要测算生物资源消费、能源消费和水资源消费足迹。污染足迹主要测算废气和生活废水、工业废水对自然生态系统带来的负荷。测算结果表明:2001—2010年辽河流域人均生态承载力和人均生态足迹均有所增加,但是生态足迹的增长速度远远大于生态承载力,致使流域内自2001与2009年生态略有盈余外,其余年份均出现生态赤字,处于不可持续发展状态。以能值-生态足迹模型测算结果为基础,基于EViews采用自回归综合移动平均模型(ARIMA),对流域内10年的生态足迹和生态承载力进行动态模拟。首先通过ADF与PP单位根检验时间序列的平稳性;其次分析序列的自相关函数图和偏自相关函数,初步确定AR和MA的阶次;再根据R2、AIC及SC准则,进行模型参数估计并诊断分析;最后确定最佳模拟模型。以ARIMA模型预测2011—2015年辽河流域生态足迹和生态承载力的演变趋势。预测结果表明,人均生态足迹在未来5年内会继续呈直线式增长,到2015年达到7.387 8 hm2,是2001年的2.16倍;而人均生态承载力在2011年之后开始下降,生态赤字继续扩大,到2015年增长到-4.167 67,约为2005年的10倍,流域内不可持续发展形势会更加恶化。最后提出辽河流域生态安全建设的对策。能值-生态足迹模型测算结果与实地调研基本相符,较真实反映了辽河流域可持续发展状况。基于ARIMA模型模拟预测结果可为未来流域开发和建设提供参考依据。     

桂西北喀斯特区可持续发展现状评价与趋势预测

以广西河池市为例,运用生态足迹方法对区域可持续发展状态进行定量分析,应用GM(1,1)模型对区域人均生态足迹和人均生态承载力进行趋势预测.结果表明:该区1985-2006年人均生态足迹持续上升,增加近2倍,而人均生态承载力逐步下降,降幅达12.6%,由生态盈余转变为生态赤字,呈不可持续发展状态;1990-2001年人均生态足迹变化幅度最大,达120.76%,但2001年后趋于缓和;对生态足迹构成的分析表明,耕地和草地消耗最大,草地足迹正向变化最为剧烈,所占生态足迹构成比例由12.88%增至30.12%;对河池市人均生态足迹和人均生态承载力的趋势预测结果显示,未来9a人均生态足迹仍继续上升,生态赤字将相应进一步扩大.     

区域地下水资源承载力综合评价的集对分析方法

集对分析是一种新的不确定性分析方法,针对关于确定-不确定系统给出了分析背景下的联系度表达式,由于其联系度概念具有鲜明的辨证性、完整性,成为处理不确定性问题的独具特色的思想方法。应用集对分析法对关中地区的地下水资源承载力进行了综合评价,评价结果得出:西安地下水资源承载力已达Ⅲ级,该地区地下水资源开发已接近饱和值;咸阳、宝鸡、关中平原、渭南等地区地下水资源承载力属于Ⅱ级,地下水资源开发利用已有相当的规模,但仍有一定的开发利用潜力。评价结果与模糊综合评价、投影寻踪法和物元分析法的结果基本相同。本方法具有概念明确、计算简单,结果合理。该方法为水文水资源的分析、评价提供了一种更为简便的方法。     

邹城市水资源承载力研究

本文明确了水资源综合承载力的定义和研究意义。研究中按照可持续发展的思路,根据邹城市水资源条件和开发状况,建立由供水系统和需水系统及其组成或承载对象构成的评价指标体系;利用人口与经济组成的多目标评价模型研究邹城市水资源的承载力,计算确定出2015年邹城市在人口增长速度不高于5%的情况下,水资源能够承载的经济最佳增长速度在9%左右。     

生态承载力的概念及其研究方法

生态承载力研究是可持续发展科学领域关注的热点问题,是判定可持续发展的重要分析手段,对生态承载力的概念和评价方法的研究有利于可持续发展科学的发展与完善。对国内外相关研究中的生态承载力概念进行了总结,并深入探讨了不同学者对于生态承载力概念达成的共识及存在的分歧,在此基础上提出了生态承载力概念的内涵。依据生态承载力评价的思路,将国内外生态承载力评价方法分为3类,第1类是指标体系评价法,第2类是以能量、物质流为基础的产品周期评价,第3类是综合性评价。上述评价方法在处理复杂系统问题上都有各自的优缺点,需要评价者根据评价目的采用互补的方式对方法进行集成,加强综合集成的方法在生态承载力评价中的应用。最后,结合生态承载力研究的发展趋势,分析了目前生态承载力研究的不足,提出了生态承载力中主动因子与被动因子、生态承载力预测及其与区域规划的结合、经济发展和科技进步对生态承载力的影响、生态承载力方法改进等亟待开展的研究内容。     

Reproduction of the invasive slipper limpet, Crepidula fornicata, in the Bay of Brest, France

The reproduction of Crepidula fornicata was studied in the Bay of Brest in order to characterise the first step of the reproductive cycle of this invasive species. The survey was carried out from 2000 to 2003 and different parameters were measured, namely, the percentage of the different sexual stages, the straight length of the shell and the percentage of brooding females using a survey of the embryonic development and the fecundity. The juvenile frequency increases generally from mid-June or mid-August, depending on the year. In 2001 and 2003, a first peak was observed as early as May, but it was followed by a rapid disappearance of the individuals. The sex-ratio female/male increased from 0.22 to 0.46 between 2001 and 2003. The sex change between intermediates and females took place mainly in summer and was well marked in 2001 and 2003. The survey of the embryonic development in the egg capsules brooded by the females provided an annual phenology of the laying and hatching processes. The laying period extends from February to September with three to four major periods of egg-laying per year and corresponding hatching periods about 1 month later. Each female lays two to four times per year on average. The first egg-laying concerned fewer females than subsequent ones, except in 2003, and exhibited a higher fecundity. The annual mean of the number of eggs for each stage was not significantly different, thus indicating no significant mortality rate during embryonic development. For the C. fornicata population in the Bay of Brest, several reproductive characteristics tend to highlight its invasive capacity: (1) a long reproductive period, (2) reproduction in a ‘multi-trials’ process equivalent to a spreading out of the risks and (3) a relatively high fecundity.     

Arsenic mineralization,source, distribution,and abundance in the Kutahya region of the western Anatolia,Turkey

Environmental exposure to arsenic (As) in the Kutahya region of the western Anatolia, Turkey has been reported to cause various types of arsenic-associated skin disorders (Dogan, Dogan, Celebi, & Baris, 2005). A geological and mineralogical study was conducted to find the sources and distribution of the As. Geogenic (background) levels were measured in samples collected from various sources in the Gediz, Simav, Tavsanli, Emet, Yoncali, Yenicekoy, and Muratdagi areas of the Kutahya region. Based on this analysis, we determined that natural sources are a domineering factor affecting the distribution of As, which was found: (1) mainly in evaporitic minerals, including colemanite (269–3900 ppm) and gypsum (11–99,999 ppm), but also in alunite (7–10 ppm) and chert (54–219 ppm); (2) in secondary epithermal gypsum, which has a high concentration of As in the form of realgar and orpiment along fracture zones of Mesozoic and Cenozoic carbonate aquifers; (3) in rocks, including limestone/dolomite (3–699 ppm) and travertine (5–4736 ppm), which are relatively more enriched in As than volcanics (2–14 ppm), probably because of secondary enrichment through hydrological systems; (4) in coal (1.9–46.5 ppm) in the sedimentary successions of the Tertiary basins; (5) in thermal waters, where As is unevenly distributed at concentrations varying from 0.0–0.9 mg/l. The highest As concentrations in thermal water (Gediz and Simav) correlate to the higher pH (7–9.3) and T (60–83°C) conditions and to the type of water (Na–HCO₃–SO₄ with high concentration of Ca, Mg, K, SiO₂, and Cl in the water). Changes in pH can be related to some redox reactions, such as the cation exchange reactions driving the dissolution of carbonates and silicates. Fe-oxidation, high pH values (7–9.3), presence of other trace metals (Ni, Co, Pb, Zn, Al), increased salinity (Na, Cl), high B, Li, F, and SiO, high Fe, SO₄ (magnetite, specularite-hematite, gypsum), and graphite, and the presence of U, Fe, Cu, Pb, Zn, and B, especially in the Emet, Gediz, and Simav areas, are the typical indicators for the geothermally affected water with high As content. A sixth source of As in this region is the ground (0.0–10.7 mg/l) and the surface waters (0.0022–0.01 mg/l), which are controlled by water–rock interaction, fracture system, and mixing/dilution of thermal waters. The high As concentration in groundwater corresponds to the areas where pathological changes are greatest in the habitants. Arsenic in ground water also effects ecology. For example, only Juriperus oxycedrus and J. varioxycedrus types of vegetation are observed in locations with the highest concentration of As in the region. Branches and roots of these plants are enriched in As.     

Distribution of aromatic amines,phenols, chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China

• The total organic pollutant concentrations in sediment were 27.4-1620 ng/g. • The phenol concentrations were relatively high in the sediment of the Dianchi Lake. • Average total concentrations decreased as follows: Caohai>Waihai>Haigeng Dam. • 1,4-dichlorobenzene, 3- or 4-methylphenol, 1,2,4-trichlorobenzene might be risks. Organic pollutants are widespread environmental pollutants with high toxicity, persistence, and bioaccumulation. Our aim was to investigate the distribution of aromatic amines, phenols, chlorobenzenes, and naphthalenes in the surface sediment of the Dianchi Lake, China. Nineteen surface sediment samples were collected from the Dianchi Lake, and 40 types of organic pollutants were analyzed via gas chromatography–mass spectrometry. The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62 × 10³ ng/g. The concentrations of phenols were much higher than those in other water bodies but still within a controllable range, whereas the concentrations of the other organic pollutant classes were similar or even lower. The detection ratio of 3- or 4-methylphenol was the highest (100.00%) among the pollutants. The average total organic pollutant concentrations decreased in the following order: Caohai (540 ng/g)>the middle of Waihai (488 ng/g)>the edge of Waihai (351 ng/g)>Haigeng Dam (90.4 ng/g). Pearson analysis showed a strong correlation among 1-methylnaphthalene, 2-methylnaphthalene, 1,3-dinitronaphthalene, and 1,4-dinitronaphthalene (p<0.01). Caohai, the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration; meanwhile, 1,4-dichlorobenzene, 3- or 4-methylphenol and 1,2,4-trichlorobenzene were more likely to cause risks.     

Light, sediment, temperature, and the early life-history of the habitat-forming alga Cystoseira barbata

Recruitment is essential for the maintenance of populations, but far more is typically known about the more easily-observed adult stages than their smaller, often microscopic early life-history counterparts. This discrepancy can be particularly problematic for populations of foundation species that create biogenic habitat for a multitude of other taxa, but are themselves prime candidates for exploitation, fragmentation, and loss, and therefore become the focus of restoration efforts partly or fully dependent on recruitment. The purpose of this study was to improve ecological understanding for early life-history stages of the habitat-forming marine alga Cystoseira barbata (Stackhouse) C. Agardh (Fucales: Sargassaceae), member of a genus that has experienced considerable fragmentation and population decline on European coasts. Using experimental manipulations of water temperature, light intensity, and sediment accumulation, we observed that sediment virtually precluded recruitment of C. barbata, and greatly impacted the survival of recently settled germlings (up to ~83% mortality). Stronger intensities of light facilitated the growth of germlings, including the capacity for ~50% of them to outgrow detrimental sediment and survive. Temperature (10 vs. 16°C) had no effect on early recruitment, survival, or growth. This information helps to identify likely causes and locations of recruitment failure, and by extension, the conditions needed (either naturally or through human intervention) to facilitate recruitment and possible habitat restoration. Ultimately, this knowledge can increase our capacity to predict population persistence and the likely success of restoration efforts.     

Density-dependent growth in the Atlantic surfclam, Spisula solidissima, off the coast of the Delmarva Peninsula, USA

Spisula solidissima (Dillwyn, 1817) is a large, suspension-feeding bivalve, whose range extends from Nova Scotia to South Carolina. This species is harvested commercially. Shell length and age data were collected for this species from 1980 to 1994 during surveys of population size and structure. These data were used to examine the relationship between the growth rate of S.␣solidissima and intraspecific density. The null hypothesis was that density (represented by number of individuals per tow) would have no effect on rate of growth. A negative relationship would support the alternative hypothesis, that intraspecific competition had taken place. This analysis focused on the surfclam population offshore from the Delmarva Peninsula, USA because: (1) a major recruitment event occurred in 1977, (2) clam fishermen had reported “stunted” surfclams in that area, (3) a wide range of local densities were available to examine, and (4) the existence of a closed area within the study area set up an interesting contrast with areas left open to harvesting. Maps of surfclam abundance across the Delmarva region demonstrate that areas of highest density have generally remained in the same location through time. The results suggested that intraspecific competition has been important in structuring this population. Based on data from 1980 to 1992, shell length was significantly reduced at high density, and a significant interaction between age and density was observed. Growth modeling indicated decreased asymptotic lengths and growth rates with increasing density. In nine out of ten pairwise randomization tests, fitted von Bertalanffy growth curves, representing different densities, were significantly different from each other. High densities of clams have persisted in the area that was closed to harvesting for 11 years (1980 to 1991). In 1994, length at age was significantly less in this closed area compared to that in the surrounding area. This effect was apparent in clams from 3 to 17 years of age, and most pronounced in the cohort that recruited to the Delmarva region in high numbers in 1977. Lower growth rates within the closed area have management implications for the optimal duration of closures. Received: 16 May 1997 / Accepted: 7 October 1997     

Microbial communities of the carapace, gut, and hemolymph of the Atlantic blue crab, Callinectes sapidus

The Atlantic blue crab Callinectes sapidus is an important fisheries resource that is subject to mortality and morbidity from hemolymph infections. We used culture-independent methods based on the analysis of 16S rRNA genes to characterize and quantify the microflora from the carapace, gut, and hemolymph of C. sapidus with the goals of (1) characterizing the C. sapidus microbial assemblage and (2) identifying the reservoirs of potential pathogens associated with the crab. We found that the carapace, gut and hemolymph microflora have a core Proteobacteria community with contributions from other phyla including Bacteroidetes, Firmicutes, Spirochetes, and Tenericutes. Within this Proteobacteria core, γ-Proteobacteria, including the members of the Vibrionaceae that are closely related to potential pathogens, dominate. Bacteria closely related to hemolymph pathogens were found on the carapace, supporting the hypothesis that punctures, molting damage, or broken dactyls may be routes for hemolymph infections. These results provide some of the first data on the blue crab microbial assemblage obtained with culture-independent techniques and offer insights into the routes of infection and potential bacterial pathogens associated with blue crabs.     

Logging, Conifers, and the Conservation of Crossbills

A survey of the forestry literature shows that as the age and area of coniferous forests decline, decreased conifer seed production and increased frequencies of cone failures can be expected. This would, in turn, cause declines in crossbills ( Loxia ), which specialize on the seeds held in conifer cones. In western North America, at least five different species of Red Crossbills ( L. curvirostra ) have recently been distinguished (Groth 1990); each specializes on a different species or even a single variety of conifer (Benkman 1993). Measures for conserving this diversity of crossbills include protecting mature and old-growth stands, and increasing rotation ages throughout the range of each of the required conifers. These recommendations are not unique to crossbills, but rather the loss of crossbill diversity is another reason to employ such measures.