基于生态足迹模型的红壤退化地生态恢复研究

生态足迹是衡量一个国家或地区可持续发展程度的一种方法,定量反映人类活动对生态环境的影响和破坏程度。基于生态足迹模型,采用多源数据,以红壤退化严重的福建安溪县和永定县为例,评价人类活动对其生态环境的影响作用。通过计算结果表明,其生态足迹呈现赤字,生态环境处于不平衡状态,对此,提出了有利于该区生态、经济、环境协调发展的具体生态恢复对策和措施。     

137Cs技术测量土壤侵蚀速率常用模型讨论

生态足迹方法是一种定量评价可持续发展程度的生物物理方法。通过测算人类的生态足迹与生态承载力之间的差距,定量地判断区域的发展是否处于生态承载力的范围之内,为评价区域的可持续发展提供依据。在介绍生态足迹、生态承载力的基础上,运用生态足迹模型对烟台市2002年的生态足迹进行了计算分析,结果表明烟台市2002年人均生态赤字为1.079 hm2,远远超出了其生态承载力,说明烟台市的发展处于不可持续状态。最后,提出了提高区域生态承载力,实现可持续发展的一些对策。     

应用生态足迹模型对鲁西南可持续发展能力定量测度

可持续发展定量测度的核心是确定人类是否生存于生态系统的承载力范围之内,生态足迹是一种定量测量人类对自然利用程度的新方法。以鲁西南地区为研究对象,对2006年生态足迹分为生物资源足迹、化石能源足迹、生态环境污染足迹3部分进行实证计算和分析。结果表明鲁西南2006年的人均生态足迹为3.166 hm²,人均可利用生态承载力为0.411 hm²,人均生态赤字为2.755 hm²,人均生态足迹已经远远超过人均生态承载力,表明鲁西南经济发展对生态系统的压力和强度甚高。     

宁德市基于生态足迹的可持续发展评价

 可持续发展的定量测度研究是当前国际上关于生态经济研究的前沿问题之一。生态足迹分析法是近年来发展的用于研究和判断一个国家或地区可持续发展状况的新方法。通过比较支持特定区域人类社会所有消费活动所需要的土地(生态足迹)与该区域可提供的生物生产性土地(生态承载力)可判断区域发展的可持续性。该文在介绍生态足迹概念和计算方法的基础上,以福建省宁德市2002年统计年鉴数据为依据,计算分析得到宁德市2002年人均生态足迹为0.7697hm2,人均生态承载力为0.6210 hm2,人均生态足迹赤字为0.1487hm2。反映出该市人类的生产、生活强度超过了生态系统的承载能力,区域生态系统处于人类的过度开发利用状态下。造成该市生态足迹赤字的主要影响因子是资源过度消耗、人口增长和耕地减少等     

基于生态足迹模型的经济技术开发区的生态安全分析——以福州市为例

生态足迹是衡量一个国家或地区可持续发展程度的一种方法,可定量反映人类活动对生态环境的影响和破坏程度。利用生态足迹模型,采用多源数据,以福州市经济技术开发区为例,评价人类活动对其生态环境的影响作用。分别计算了流域生态足迹、生态承载力、生态赤字以及万元GDP生态足迹,并分析其生态安全。结果表明生态足迹不断增加,且渐高于当地的生态承载力,呈现赤字,同时生态压力处于不安全状况,生态经济协调性差,生态环境处于不平衡状态,说明现有的可持续发展模式面临考验,社会经济与生态环境承受力不相协调。对此,提出了有利于该区生态、经济、环境协调发展的具体生态恢复对策和措施。     

山西省2001年生态足迹计算与分析

以2002年统计年鉴的数据为基础,利用生态足迹模型这一测度方法,对山西省的可持续发展状况以及人类对各种自然资源的利用程度进行了定量计算。结果显示,全省生态赤字达1.682km~2/cap,表明生态经济系统处于不可持续的发展状态,并分析了其原因,提出了相应的建议。     

中国1999年的生态足迹分析

自可持续发展的概念提出以来 ,科学家们一直在研究衡量可持续发展状态的指标和方法以支持可持续发展的决策。生态足迹的研究方法是 1 992年ＷｉｌｌｉａｍＲｅｅｓ和他的学生Ｗａｃｋｅｒｎａｇｅｌ提出并于 1 996年完善的。生态足迹是指按可持续发展方式 ,支持给定数量的人口消费所需要的生物生产型土地面积[1]。由于是采用看得见的足迹来反映人类消费对自然的影响 ,生态足迹研究方法自提出以来 ,已经得到了广泛地应用[2 ]。本文旨在用当前国际上流行的生态足迹理论 ,来定量衡量中国的可持续发展状况。1　研究方法生态足迹的计算是基于 :对…     

延安市2001-2006年生态足迹分析

生态足迹模型近年来被越来越多地应用于区域经济可持续发展的定量研究中,它可以形象的反映出人类经济活动对生态环境影响的程度.以延安市2001-2006年统计年鉴数据为依据,运用该模型对延安地区生态足迹进行计算,并对结论进行分析,得出延安地区生态足迹需求远远大于生态供给,发展处于不可持续状态.最后提出了地区可持续发展的几点建议.     

南方丘陵山区生态足迹计算和分析--以韩江上游梅江区为例

可持续性度量是可持续发展研究的重要课题，生态足迹作为一种可持续发展状况的定量测度，反映了人类对自然利用程度。以2003年梅江区统计年鉴的数据为依据，对梅江区2003年的生态足迹进行了测算。结果表明，梅江区2003年人均生态足迹为0．9583hm^2／cap，实有人均生态生产性面积为0．2267hm^2／cap，人均生态赤字为0．7315hm^2／cap。梅江区生态足迹及其赤字主要来源于能源、水域、耕地和草地类产品的消费，林地类产品和建设用地类产品出现了一定的盈余。在剖析原因的基础上，提出了促进梅江区社会经济可持续发展的几点政策建议。     

四川省万源市可持续发展状况的生态占用分析

生态占用方法是一种可持续发展程度的生物物理评价方法。该方法从一个全新的角度考虑人类及其发展与生态环境的关系,通过跟踪区域能源与资源消费,将它们转化为这种物质流所必需的各种生物生产土地的面积,给出一个核算全球、国家、地区以及家庭和个人对自然资本利用的简明框架。该方法通过测算人类的生态占用与生态承载力之间的差距,定量地判断区域的发展是否处于生态承载力的范围之内,给评定对象的可持续发展提供科学依据。利用生态占用分析法以万源市为例,对其生态经济协调发展的状态进行实证研究。结果表明:供需总量呈现出非均衡特点,存在严重的生态赤字,目前处于不可持续发展状态;生态供需结构存在明显的不对称性;自然资源利用率低于西部和全国平均水平。最后;对其产生生态赤字的原因和减小生态赤字的可行性作简要分析。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.