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1Effects of N Forms and Rates on Vegetable Growth and Nitrate Accumulation显示文摘Experiments were carried out on a vegetable field with Peking cabbage (Brassica pekinensis (Lour.)Rupr.), cabbage (Brassica chinensis var. Oleifera Makino and nemoto), green cabbage (Brassica chinensis L.), spinach (Spinacia oleracea L.) and rape (Brassica campestris L.) to study the effects of N forms and N rates on their growth and nitrate accumulation. The results indicated that application of ammonium chloride,ammonium nitrate, sodium nitrate and urea significantly increased the yields and nitrate concentrations of Peking cabbage and spinach. Although no significant difference was found in the yields after application of the 4 N forms, nitrate N increased nitrate accumulation in vegetables much more than ammonium N. The vegetable yields were not increased continuously with N rate increase, and oversupply of N reduced the plant growth, leading to a yield decline. This trend was also true for nitrate concentrations in some vegetables and at some sampling times. However, as a whole, the nitrate concentrations in vegetables were positively correlated with N rates. Thus, addition of N fertilizer to soil was the major cause for increases in nitrate concentrations in vegetables. Nitrate concentrations were much higher in roots, stems and petioles than in blades at any N rate.WANG Zhao-Hui and LI Sheng-XiuCollege of Resources and Environmental Sciences, Northwestern Science and Technology University of Agriculture and Forestry, Yangling 712100 (China). E-mail: w-zhaohui@263.net 2003Pedosphere2003,13,4:54
2Carbon density and distribution of six Chinese temperate forests显示文摘Quantifying forest carbon(C) storage and distribution is important for forest C cycling studies and terrestrial ecosystem modeling.Forest inventory and allometric approaches were used to measure C density and allocation in six representative temperate forests of similar stand age(42-59 years old) and growing under the same climate in northeastern China.The forests were an aspen-birch forest,a hardwood forest,a Korean pine plantation,a Dahurian larch plantation,a mixed deciduous forest,and a Mongolian oak forest.There were no significant differences in the C densities of ecosystem components(except for detritus) although the six forests had varying vegetation compositions and site conditions.However,the differences were significant when the C pools were normalized against stand basal area.The total ecosystem C density varied from 186.9 tC hm-2 to 349.2 tC hm-2 across the forests.The C densities of vegetation,detritus,and soil ranged from 86.3-122.7 tC hm-2,6.5-10.5 tC hm-2,and 93.7-220.1 tC hm-2,respectively,which accounted for 39.7% ± 7.1%(mean ± SD),3.3% ± 1.1%,and 57.0% ± 7.9% of the total C densities,respectively.The overstory C pool accounted for > 99% of the total vegetation C pool.The foliage biomass,small root(diameter < 5mm) biomass,root-shoot ratio,and small root to foliage biomass ratio varied from 2.08-4.72 tC hm-2,0.95-3.24 tC hm-2,22.0%-28.3%,and 34.5%-122.2%,respectively.The Korean pine plantation had the lowest foliage production efficiency(total biomass/foliage biomass:22.6 g g-1) among the six forests,while the Dahurian larch plantation had the highest small root production efficiency(total biomass/small root biomass:124.7 g g-1).The small root C density decreased with soil depth for all forests except for the Mongolian oak forest,in which the small roots tended to be vertically distributed downwards.The C density of coarse woody debris was significantly less in the two plantations than in the four naturally regenerated forests.The variability of C allocation patterns in a specific forest is jointly influenced by vegetation type,management history,and local water and nutrient availability.The study provides important data for developing and validating C cycling models for temperate forests.ZHANG QuanZhi & WANG ChuanKuan* College of Forestry,Northeast Forestry University,Harbin 150040,China 2010Science China(Life Sciences)2010,53,7:36
3第六次全国森林资源清查及森林资源状况显示文摘在系统分析第六次(1999年-2003年)森林资源连续清查总体情况的基础上,总结了此次清查的五个特点;从森林资源结构、资源数量、区域分布、资源发展变化等方面揭示了此次资源清查的最新成果;剖析了森林资源发展中存在的问题,并提出了相应措施。清查结果显示:全国林业用地面积2.85亿hm^2,森林面积1.75亿hm^2,森林覆盖率18.21%,森林蓄积量124、56亿m^3;人工林面积0.53亿hm^2,蓄积15.05亿m^3。Department of Forest Resources Management,State Forestry Administration 2005绿色中国(理论版)2005,,01M:32
4Diversity and ecological distribution of endophytic fungi associated with medicinal plants显示文摘A total of 973 isolates of endophytic fungi were recovered from 1144 tissue fragments of the six me-dicinal plant species belonging to 4 families collected in the Beijing Botanical Garden. Of these isolates 778 sporulated and were identified into 21 taxa by morphological characteristics. Among the taxa 11 belonged to Coelomycetes, 6 to Ascomycetes, and 4 to Hyphomycetes. Various numbers of endophytic fungi (5―8 taxa) were obtained from each plant. Alternaria alternata was the dominant species in the 6 plants, and Microsphaeropsis conielloides was also dominant in Eucommia ulmoides. There were high colonization rates (47.9%―63.1%) and isolation rates (0.7―0.93) of endophytic fungi, and they were conspicuously higher in twigs than those in leaves in the 6 plants examined. The colonization and isolation rates of endophytic fungi increased with the twig age. The results based on the analyses of cluster and Sorenson's similarity coefficients indicated that some endophytic fungi showed a certain degree of host and tissue preference.SUN JianQiu1,2,3, GUO LiangDong1, ZANG Wei2,3, PING WenXiang4 & CHI DeFu3 1 Systematic Mycology and Lichenology Laboratory, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China 2 College of Life Science and Engineering, Qiqihar University, Qiqihar 161006, China 3 College of Forestry, Northeast Forestry University, Harbin 150040, China 4 College of Life Science, Heilongjiang University, Harbin 150080, China 2008Science China(Life Sciences)2008,51,8:34
5Invasive mechanism and management strategy of Bemisia tabaci(Gennadius) biotype B:Progress report of 973 Program on invasive alien species in China显示文摘Bemisia tabaci(Gennadius) biotype B,called a 'superbug',is one of the most harmful biotypes of this species complex worldwide.In this report,the invasive mechanism and management of B.tabaci biotype B,based on our 5-year studies,are presented.Six B.tabaci biotypes,B,Q,ZHJ1,ZHJ2,ZHJ3 and FJ1,have been identified in China.Biotype B dominates the other biotypes in many regions of the country.Genetic diversity in biotype B might be induced by host plant,geographical conditions,and/or insecticidal application.The activities of CarE(carboxylesterase) and GSTs(glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants,which might have increased its resistance to insecticides.The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants.Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes.The indigenous B.tabaci biotypes were displaced by the biotype B within 225 d.The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes.B.tabaci biotype B displaced Trialeurodes vaporariorum(Westwood) after 4-7 generations under glasshouse conditions.Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T.vaporariorum.Greater ability of the biotype B to switch to different host plants may enrich its host plants,which might enable it to better compete with T.vaporariorum.Native predatory natural enemies possess greater ability to suppress B.tabaci under field conditions.The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids.The present results provide useful information in explaining the mechanisms of genetic diversity,evolution and molecular eco-adaptation of biotype B.Furthermore,it provides a base for sustainable management of B.tabaci using biological and ecological measures.WAN FangHao1,ZHANG GuiFen1,LIU ShuSheng2,LUO Chen3,CHU Dong4,ZHANG YouJun4,ZANG LianSheng2,JIU Min2,Lü ZhiChuang1,CUI XuHong1,ZHANG LiPing4,ZHANG Fan3,ZHANG QingWen5,LIU WanXue1,LIANG Pei5,LEI ZhongRen1 & ZHANG YongJun1 1 State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection,Chinese Acadeny of Agriculture Sciences,Beijing 100094,China 2 Institute of Applied Entomology,Zhejiang University,Hangzhou 310029,China 3 Institute of Plant and Environment Protection,Beijing Academy of Agricultural and Forestry Sciences,Beijing 100089,China 4 Institute of Vegetables and Flowers,Chinese Acadeny of Agricullare Sciences,Beijing 100081,China 5 Department of Entomology,China Agriculture University,Beijing 100094,China 2009Science China(Life Sciences)2009,52,1:30
6Map and analysis of microsatellites in the genome of Populus: The first sequenced perennial plant显示文摘Environmental Sciences Division, Oak Ridge National Laboratory, TN, USA We mapped and analyzed the microsatellites throughout 284295605 base pairs of the unambiguously assembled sequence scaffolds along 19 chromosomes of the haploid poplar genome. Totally, we found 150985 SSRs with repeat unit lengths between 2 and 5 bp. The established microsatellite physical map demonstrated tr at SSRs were distributed relatively evenly across the genome of Populus. On average, These SSRs occurred every 1883 bp within the poplar genome and the SSR densities in intergenic regions, introns, exons and UTRs were 85.4%, 10.7%, 2.7% and 1.2%, respectively. We took di-, tri-, tetra-and pentamers as the four classes of repeat units and found that the density of each class of SSRs decreased with the repeat unit lengths except for the tetranucleotide repeats. It was noteworthy that the length diversification of microsatellite sequences was negatively correlated with their repeat unit length and the SSRs with shorter repeat units gained repeats faster than the SSRs with longer repeat units. We also found that the GC content of poplar sequence significantly correlated with densities of SSRs with uneven repeat unit lengths (tri-and penta-), but had no significant correlation with densities of SSRs with even repeat unit lengths (di-and tetra-). In poplar genome, there were evidences that the occurrence of different microsatellites was under selection and the GC content in SSR sequences was found to significantly relate to the functional importance of microsatellites.LI ShuXian & YIN TongMing College of Environment and Forest Resources, Nanjing Forestry University, Nanjing 210037, China Environmental Sciences Division, Oak Ridge National Laboratory, TN, USA 2007Science China(Life Sciences)2007,50,5:25
7Hydrogen peroxide-induced changes in intracellular pH of guard cells precede stomatal closure显示文摘Epidermal bioassay demonstrated that benzylamine, a membrane-permeable weak base, can mimick hydrogen peroxide (H2O2) to induce stomatal closure, and butyric acid, a membrane-permeable weak acid, can partly abolish the H2O2-induced stomatal closure. Confocal pH mapping with the probe 5-(and-6)- carboxy seminaphthorhodafluor- 1 - acetoxymethylester (SNARF-1-AM) revealed that H2O2 leads to rapid changes in cytoplasmic and vacuolar pH in guard cells of Viola faba L, i. e. alkalinization of cytoplasmic areas occur red in parallel with a decrease of the vacuolar pH, and that butyric acid pretreatment can abolish alkalinization of cytoplasmic areas and acidification of vacuolar areas of guard cells challenged with H2O2. These results imply that the alkalinization of cytoplasm via efflux of cytosol protons into the vacuole in guard cells challenged with H2O2 is important at an early stage in the signal cascade leading to stomatal closure.ZHANG XIAO, FA CAI DONG, JUN FENG GAO, CHUN PENG SONG (Department of Biology, Henan University, Kaifeng 475001, China) (College of Life Sciences, Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, China) 2001Cell Research2001,11,1:24
8The biomass and aboveground net primary productivity of Schima superba-Castanopsis carlesii forests in east China显示文摘The biomass and productivity of Schima superba-Castanopsis carlesii forests in Tiantong,Zhejiang Province,were determined using overlapping quadrants and stem analyses.The total community biomass was(225.3±30.1) t hm-2,of which the aboveground parts accounted for 72.0% and the underground parts accounted for 28.0%.About 87.2% of biomass existed in the tree layer.The resprouting biomass was small,of which over 95.0% occurred in the shrub layer.The productivity of the aboveground parts of the community was(386.8±98.9) g m-2a-1,in which more than 96.0% was present at the tree level.The trunk's contribution to productivity was the greatest,while that of leaves was the smallest.In China,the community biomass of subtropical evergreen broadleaved forests differs significantly with the age of the forest.The community biomass of the 52-year-old S.superba-C.carlesii forests in this study was lower than the average biomass of subtropical evergreen broadleaved forests in China,and was lower than the biomass of other subtropical evergreen broadleaved forests elsewhere in the world.Moreover,its productivity was lower than the model estimate,indicating that without disturbance,this community has great developmental potential in terms of community biomass and productivity.YANG TongHui1,2,SONG Kun1,DA LiangJun1*,LI XiuPeng3 & WU JianPing1 1School of Resources and Environment Science,East China Normal University,Shanghai 200062,China 2Ningbo Academy of Agricultural Science,Ningbo 315040,China 3Ningbo Technology Extension Center for Forestry and Specialty Forest Products,Ningbo 315012,China 2010Science China(Life Sciences)2010,53,7:23
9Biomass and carbon dynamics of a tropical mountain rain forest in China显示文摘Biometric inventories for 25 years,from 1983 to 2005,indicated that the Jianfengling tropical mountain rain forest in Hainan,China,was either a source or a modest sink of carbon.Overall,this forest was a small carbon sink with an accumulation rate of(0.56±0.22) Mg C ha-1yr-1,integrated from the long-term measurement data of two plots(P9201 and P8302).These findings were similar to those for African and American rain forests((0.62±0.23) Mg C ha-1yr-1).The carbon density varied between(201.43±29.38) Mg C ha-1 and(229.16±39.2) Mg C ha-1,and averaged(214.17±32.42) Mg C ha-1 for plot P9201.Plot P8302,however,varied between(223.95±45.92) Mg C ha-1 and(254.85±48.86) Mg C ha-1,and averaged(243.35±47.64) Mg C ha-1.Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months.Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest.CHEN DeXiang1*,LI YiDe1,LIU HePing2,XU Han1,XIAO WenFa3,LUO TuShou1,ZHOU Zhang4 & LIN MingXian1 1Research Institute of Tropical Forestry,Chinese Academy of Forestry,Guangzhou 510520,China 2Department of Physics,Atmospheric Science and Geoscience,Jackson State University,MS 39217,USA 3Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,Beijing 100091,China 4Department of Ecology,College of Urban and Environmental Sciences,Peking University,Beijing 100872,China 2010Science China(Life Sciences)2010,53,7:20
10Effect of Slash Burning on Nutrient Removal and Soil Fertility in Chinese Fir and Evergreen Broadleaved Forests of Mid-Subtropical China显示文摘A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.YANG YUSHENG, GUO JIANFEN, CHEN GUANGSHUI, HE ZONGMING and XIE JINSHENGFujian Agriculture and Forestry University, Nanping 353001 (China) 2003Pedosphere2003,13,1:19
11Landscape ecological assessment and eco-tourism development in the South Dongting Lake Wetland, China显示文摘As an important resource and the living environment of mankind, wetland has become gradually a highlight, strongly concerned and intensively studied by scientists and sociologists. The governments in the world and the whole society have been paying more and more attention on it. The Dongting Lake of China is regarded as an internationally important wetland. For a rational development and protection of the wetland, an investigation and studied on its resources and its value to tourism in the South Dongting Lake was conducted, to create an assessment system of the ecological landscapes, and to evaluate qualitatively and quantitatively the value of wetland landscape to the eco-tourism. The results showed that the scenic value of the South Dongting Lake Wetland satisfied the criterion of AAAA grade of China national scenic attraction. The eco-tourism value of the landscape cultures in the South Dongting Lake Wetland was discussed with emphasis. It were formulated that a principle and frame of sustainable exploitation of the wetland landscapes and it was proposed as well that establishing a Wetland Park and developing eco-tourism in the South Dongting Lake. Wetland is a fragile ecosystem with low resistance to the impact of the exploitation. Thus, we must pay intensively attention to the influence of exploitation on the landscape, take the ecological risk in account to employ a right countermeasure and avoid the negative affection.HE Ping 1,2, WANG Bao-zhong 1,3 (1.Central South Forestry University, Zhuzhou 412006, China 2.China International Engineering Consulting Corporation, Beijing 100044, China 3.Nanjing University, Nanjing 210093, China 2003Journal of Environmental Sciences2003,15,2:19
12Carbon isotope ratios of C_(4) plants in loess areas of North China显示文摘Carbon isotope ratios (δ 13C) of 89 C4 plant samples were determined from the loess area in North China. δ 13C values vary between –10.5‰ and –14.6‰ with a mean of –12.6‰. Along a pre-cipitation gradient from the semi-moist area to the semiarid area, then to the arid area, the δ 13C val-ues of C4 plants show a slight decreasing trend. The δ 13C values of C4 plants in the dry season are found lower than those in the wet season. These trends are opposite to those observed for C3 spe-cies.WANG Guoan1,2,3, HAN Jiamao 2, ZHOU Liping3, XIONG Xiaogang4, TAN Ming2, WU Zhenhai5 & PENG Jun6 1. Department of Plant Nutrition, China Agricultural University, Beijing 100094, China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 3. College of Environmental Sciences, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China 4. Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 5. Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, China 6. Network Center, China Agricultural University, Beijing 100094, China 2006Science China Earth Sciences2006,49,1:16
13贵州省喀斯特石漠化地区生态重建工程建设的探讨显示文摘对我省石漠化地区的自然地理条件、森林覆盖率、生产力现状及资源利用进行调查研究.提出实施生态重建的必要性、有利条件及工程实施中的原则和措施。(Department of Forestry) 1998贵州林业科技1998,26,4:16
14Quantitative analysis of soil pores under natural vegetation successions on the Loess Plateau显示文摘Soil pore is a key attribute of the soil structure that affects soil reservoir under natural vegetation recovery on the Loess Plateau.This study is to quantitatively analyze soil pore parameters,measured with Computed Tomography(CT) at 15-57 mm depths under five different vegetation succession stages using a concept of substituting 'space' for 'time' in the Ziwuling Forest Region of the Loess Plateau.The results showed that the soil pore parameters,such as pore number,porosity,circularity,and fractal dimension,increased significantly under the natural vegetation successions and varied with the pattern climax community stage>pioneering arbor community stage>scrub community stage>herbaceous community stage>abandoned farmland stage,indicating that natural vegetation recovery could remarkably improve soil pore characteristics.With the vegetation succession,this positive effect will be strengthened gradually,which means that the soil pore parameters may appear to be best at the climax community stage.Soil organic matter content increased linearly with the soil pore parameters(P<0.001).Increased organic matter accumulation was one of the major reasons for the changes in soil pore characteristics in natural vegetation succession.ZHAO ShiWei1,ZHAO YongGang1,2 & WU JinShui3 1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest Agriculture & Forestry University,Yangling 712100,China 2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3 Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China 2010Science China Earth Sciences2010,53,4:14
15Evaluation of ecosystem services of Chinese pine forests in China显示文摘Evaluation of forest ecosystem services is a hot topic,both in China and at abroad,but it has not yet obtained a consistency of evaluation indicator systems and evaluation methods.Under the framework of evaluation criteria to be implemented for forest ecosystem services,years of consecutive observation data from Long Term Ecological Research Stations affiliated to Chinese Forest Ecosystem Research Network(CFERN),forest resource inventory and public data were applied to carry out a detailed and dynamic evaluation on the physical quantity and value of ecosystem services of Chinese pine forests in China.The results showed that the above services had the total value and unit value of 1144.9640 billion(1.1449640×10 12 )RMB and 52.074 thousand RMB per hectare per year,respectively during the 9th Five-year Plan(1996―2000),and of 1190.5461 billion RMB and 52.101 thousand RMB per hectare per year,respectively,during the 10th Five-year Plan(2001―2005).For Chinese pine forests,water conservation was 40.40 hundred million cubic meters annually,soil conservation was 67 million tons and C fixation 9 million tons annually,production of healthful negative ions was 1.96×10 20 , absorption of SO2 was 5.02 hundred million kilograms and dust-catching was 759.10 hundred million kilograms. Among the 15 provinces of China with Chinese pine forests,the biggest beneficiary from ecosystem services was Liaoning Province;while Hunan Province was the smallest beneficiary between the 9th Five-year Plan.GUO Hao ,WANG Bing,MA XiangQian,ZHAO GuangDong&LI ShaoNing Research Institute of Forest Ecology Environment and Protection of CAF,Key Laboratory of Forest Ecological Environment of State Forestry Administration,Beijing 100091,China 2008Science China(Life Sciences)2008,51,7:14
16Soil Fertility in Agroforestry System of Chinese Fir and Villous Amomum in Subtropical China显示文摘A trial of interplanting and non-interplanting villous amomum (Amomum villosum Lour.) under the canopy of Chinese fir (Cunninghamia lanceolata Hook.) at age 22 was established in Sanming, Fujian of China, and a survey on soil fertility was carried out 10 years after its establishment. Compared with the control (non-interplanting), the properties of soil humus in agroforestry system were ameliorated, with a higher level of humification and resynthesis of organic detritus. The soil microbial population and enzymatic activities were both higher under the influence of villous amomum. Both the nutrient supplying and nutrient conserving capacities of the soil were improved. This agroforestry system exhibited an advantage of improved soil fertility as well as an accelerated growth of Chinese fir, it was, therefore, a sustainable management system suited for Chinese fir in South China.YANG YUSHENG, CHEN GUANGSHUI and YU XINTUO Fujian Agriculture and Forestry University, Nanping 353001 (China) 2001Pedosphere2001,11,4:14
17Spatial heterogeneity of the driving forces of cropland change in China显示文摘By using digital satellite remote sensing data acquired in 1987―1989 and 1999―2000 and GIS combined with the natural and socio-economic data, this paper drew an integrated zonation of the cropland change and its driving forces in China. The results indicated that the cropland change in the study period was constrained by geographical factors and driven by cli-mate change as well as socio-economic system. Moreover, the regional differences of the drivers for cropland change were significant. In the midwest of China, natural condition changes and geographical background were the main constraints and drivers, while in Eastern China, social and economic changes and economic policies were the main driving forces. The cropland loss was nationwide. The dominant factors to cause this decrease included buildup of developing area to attract foreign capital and technologies, changes of industry structure due to urban in-fluence, the change of employment notions thanks to living standard improvement, rapid ur-banization due to the expansion of cities and towns, the diminished farming net income partly because of the global warming effects, and the rapid economic growth stimulated by the con-venient transportation system. These factors interact and interdepend with each other to cause the cropland loss in China recently. The reasons for the increase of cropland were primarily the cultivation and deforestation by the farmers who want to increase income. This study on the mechnism of LUCC relied on the cropland change integrated classification considering the natural or human factors both inside and outside the region, which provides a new approach to study the integrated regionalization and LUCC mechanism.LIU Xuhua1,2, WANG Jinfeng1, LIU Mingliang4,1 & MENG Bin1,2,3 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China 3. College of Arts and Sciences of Beijing Union University, Beijing 100083, China 4. School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, AL36849, USA 2005Science China Earth Sciences2005,48,12:13
18Characteristics of N Mineralization in Urban Soils of Hefei,East China显示文摘Nitrogen cycling has been poorly characterized in urban ecosystems.An in-situ buried bag incubation technique was used to quantify net rates of N mineralization and nitrification in soils of two urban sites,a street greening belt and a university campus,and a suburban site,a forest park,in Hefei,East China.The average concentration of extractable NO 3 in the surface soil (0-10 cm) was significantly higher at the urban sites than the suburban park site,whereas extractable NH + 4 concentration was significantly higher at the suburban park site than the urban sites.The forest park soil had greater potential N mineralization (148.1 μg N cm 3) than the soils from the campus (138.3 μg N cm 3) and street (99.8 μg N cm 3).The net mineralization rates varied between 1.63 and 2.69 μg N cm 3 d 1 and net nitrification rates between 0.82 and 1.02 μg N cm 3 d 1 at the suburban forest park site,but the rates varied from 1.27 to 2.41 μg N cm 3 d 1 and from 1.07 to 1.49 μg N cm 3 d 1,respectively,at the urban campus site.Both net mineralization and nitrification rates were lower during dry seasons.Results from regression analysis indicated that net N mineralization was significantly and positively correlated with soil moisture and soil C/N ratio,and was negatively correlated with soil pH.Relative nitrification was,however,significantly and negatively correlated with soil moisture and soil C/N ratio,and was positively correlated with soil pH.Mean relative nitrification was 0.763,indicating the dominance of nitrate cycling relative to ammonium cycling at the urban sites.The urban soils had the great potential for N losses compared to the suburban soils.ZHANG Kai,XU Xiao-Niu and WANG Qin School of Forestry and Landscape Architecture,Anhui Agricultural University,Hefei 230036 (China) 2010Pedosphere2010,20,2:13
19Electrophysiological and Behavioral Responses of Adult Anoplophom glabripennis (Motschulsky) to Volatile Components of Host-Plant显示文摘Electrophysiological and behavioral responses of adult A.glabripennis(Motsch.)to volatiles from ashleaf maple (Acer negundo L.) were investigated to identify semiochemicals involved in host location.Measurable electroantennogram(EAG) responses were elicited to all compounds tested,the most effective antennal stimulants were trans-2-hexen-l-al,decyl aldehyde and trans-2-hexen-1-ol.These profiles were similar between males and females.In Y-tube olfactometer bioassays,above three compounds with certain concentration,trans-2-hexen-1-al(1%),trans-2-hexen-1-ol(1%) and decyl aldehyde(10%),were significantly attractive to the adults in laboratory.The results show that either EAG or olfactory responding to a particular volatile compound are markedly influenced by the concentration.Fan Hui Li Jiquan Jin YoujuCollege of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, P. R. China 2003Forestry Studies in China2003,5,1:13
20Sustainable Management of Planted Forests in China: Comprehensive Evaluation, Development Recommendation and Action Framework显示文摘China is one of the largest countries in the world in terms of planted forests area. Planted forests play an important role in soil and water conservation, food source, timber supply and energy security, but there are still many problems waiting for immediate resolution. Based on the current development status of planted forest in China, the paper made an comprehensive analysis for the positive impact and existing problems with regard to planted forests, and then came up with policy recommendations for promoting sustainable management of planted forests, mainly including: 1) to accelerate planted forests development and improve the quality; 2) to strengthen the protection and management, and quicken the development of planted forests; 3) to enhance the scientific planning for planted forests; 4) to reinforce the management for forests harvesting so as to promote the reasonable utilization of planted forests; 5) to perfect the management system for planted forest resources and improve the managerial capacity; 6) to complete related laws and regulations and improve the policy guarantee system; 7) to reinforce the forest tenure reform and establish a sound planted forest land transference system. Finally, the paper presented the future action framework for guiding the sustainable management of planted forests in China.HE Youjun1 LI Zhiyong1 CHEN Jie1 LIU Yong1 LIU Daoping2 WU Shengfu3 QIN Yongsheng4 XU Zhijiang51. Research Institute of Forestry Policy and Information, Chinese Academy of Forestry(CAF), Beijing 100091, P. R. China 2. Quality Management Office and Department of Afforestation and Silviculture, State Forestry Administration(SFA), Beijing 100714, P. R. China 3. Green Panel Consulting, Beijing 100714, P. R. China 4. Beijing Forestry and Parks Department of International Cooperation, Beijing Municipal Bureau of Landscape and Forestry, Beijing 100029, P. R. China 5. International Cooperation Office, Yunnan Provincial Forestry Bureau, Kunmin 650021, P. R. China 2008Chinese Forestry Science and Technology2008,7,3:12
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