洞庭湖湿地观光农业资源开发利用模式研究

根据洞庭湖区湿地的同心环带状特征，将洞庭湖区湿地分为洞庭湖湖泊河汊区、洞庭湖湿地平原区和洞庭湖环湖低丘岗地区，分析了洞庭湖区湿地观光农业资源的特征和开发利用现状，并据各环带湿地观光农业资源的特点，提出了若干湿地观光农业开发模式，以期达到保护湿地生态环境，合理开发湿地观光农业资源，实现洞庭湖区湿地旅游资源可持续发展的目的。     

洞庭湖区湿地退化现状及保护对策

洞庭湖湿地是我国重要的淡水湖泊湿地之一,其生态环境对调蓄洪水、调节气候、涵养水源、净化水质、维护生物多样性等方面具有重要的作用。多年来由于人类不合理的开发利用,给湿地生态系统带来了负面影响,致使湿地严重退化。在分析洞庭湖区湿地退化现状及其原因的基础之上,提出了湿地保护与可持续利用的对策和措施。     

黄河三角洲湿地资源及可持续利用对策

按照和<中国湿地调查纲要>以及结合中国湿地分类系统和方法对黄河三角洲湿地类型进行了三级划分,并分别概述了各类湿地的基本特征.黄河三角洲复杂多样的湿地类型和生态环境蕴育了丰富的湿地资源,主要包括生物资源、土地资源、贝壳沙资源以及海洋资源,但由于人类的不合理开发利用,黄河三角洲湿地的生态环境日益恶化,部分湿地资源已开始退化甚至丧失,因此对其加以保护和合理开发利用势在必行.     

鄱阳湖湿地生态环境治理及其保护

鄱阳湖是我国最大的淡水湖泊,湖区湿地面积2698 km^2,其生态环境对调蓄洪水、调节气候、涵养水源、净化水质、维护生物多样性等方面具有重要的作用。长期以来由于人类不合理的开发利用,导致了鄱阳湖湿地面积和景观结构发生了很大变化,湿地生态环境也遭到严重破坏。在分析鄱阳湖湿地生态环境面临的主要问题及其成因的基础之上,提出了鄱阳湖湿地生态环境治理与保护的主要对策。     

新疆伊犁湿地资源现状与生态环境评价

湿地是陆地最重要的生态系统之一,在维护和调节生态环境质量方面具有不可替代的作用。建立和运用科学、实用的生态环境评价方法和指标体系,对湿地生态环境进行评价,是湿地利用、保护和管理的基础,可为制定合理的保护措施提供依据。新疆伊犁湿地是多种珍稀濒危鸟类的迁徙和繁殖地,维护区域生态平衡作用显著,可是,多年来由于不合理的开发利用,湿地面积急剧减少、生态环境质量明显下降。通过对伊犁湿地资源现状进行全面调查,生态环境质量现状以及目前湿地实施的保护与恢复措施对环境产生的影响进行综合评价和分析,全面、系统的掌握了湿地面临的生态和管理问题,对提高研究与保护利用水平,确保湿地及其资源的持续利用具有重要意义。     

洞庭湖区湿地景观变化分析

洞庭湖湿地是我国最重要湿地系统之一,具有多方面功能和价值,主要由河流、湖泊、水田、沼泽、滩地、库塘等几种类型组成。本文利用1980年、1990年、2000年3个时段的Landsat MSS和TM影像及GIS技术对洞庭湖区湿地景观变化进行研究。结果表明,洞庭湖区湿地总面积呈减少趋势,人工湿地面积有所增加,自然湿地面积减少,其中湖泊面积减少最多。这是人类和自然共同作用的结果,其中人类对湿地的改造是导致变化的主要原因,但洞庭湖的泥沙淤积是湖泊面积减少的根本原因。湿地景观的改变导致该区生态环境质量下降,生态功能退化。     

辽宁省湿地资源保护的对策分析

湿地是重要的国土资源和自然资源,具有极高的经济价值、生态价值和社会价值,辽宁省以其特有的地理位置决定了湿地的多样性,随着对湿地的不合理开发利用导致天然湿地日益减少,功能和效益下降;湿地生物多样性逐渐丧失;湿地资源遭受了严重破坏,其生态功能也严重受损。据2000年遥感调查辽宁省沼泽湿地面积较之4 a前减少了26.2%。因此,建议需要加强机构和部门之间的合作,尽快建立多部门参与、支持、协调的湿地管理机构和有效的运行机制。探讨防止湿地遭受重大破坏和威胁的途径、手段及政策措施;研究湿地保护、管理、开发等相关政策;在资源调查的基础上建立湿地综合评价指标体系和资源监测体系。在利用洪水恢复湿地生态环境的基础上,利用湿地的径流调节功能,实现洪水资源化管理。加强湿地的生态治理和污染控制。     

洞庭湖区湿地生态农业资源持续开发研究

简析了洞庭湖区湿地资源特征及农业利用现状,对湖区湿地生态农业资源进行了功能评价,并根据湖区湿地碟形盆地圈带状立体景观结构特征（即同心环带状－－湖盆中心带、湖滨中环带、外环带）,提出适应各环带湿地资源开发的若干生态农业模式,以期达到保护湖区湿地生态及湿地资源持续利用,生态效益与经济效益并重的目的。     

洞庭湖区湿地生态农业资源持续开发研究

简析了洞庭湖区湿地资源特征及农业利用现状,对湖区湿地生态农业资源进行了功能评价,并根据湖区湿地碟形盆地圈带状立体景观结构特征(即同心环带状--湖盆中心带、湖滨中环带、外环带),提出适应各环带湿地资源开发的若干生态农业模式,以期达到保护湖区湿地生态及湿地资源持续利用,生态效益与经济效益并重的目的。     

辽河三角洲湿地生态环境需水量变化研究

基于遥感和生态学的方法．对1988～2001年辽河三角洲湿地类型及面积变化所引起的最小、最适和最大生态环境需水量变化和各类湿地的单位面积生态环境需水量进行了分析。结果表明，1988～2001年辽河三角洲湿地变化引起的生态环境需水总量的变化不到3％，但面积变化对各类湿地生态环境需水量的影响却相当明显；各类湿地单位面积生态环境需水量的总排序为河流-沟渠〉湖泊-坑塘-水库=养殖用地〉水田〉苇田〉潮上带高滩。研究成果可为辽河三角洲水资源规划中湿地生态保护、区域农业结构调整所引起的生态环境需水量计算提供科学依据，也可为其他地区湿地生态环境需水量计算提供借鉴。     

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.