检索结果-南通市图书馆

Acta Botanica Sinica 2004年第2期46卷 194-201页

作者： LIGui-Cai hanxing-guo HUANGJian-Hui LaboratoryofQuantitativeVegetationEcology InstituteBeijing100093China

Using the closed-top tube incubation method, we examined the soil nitrogen (N) mineralizationand nitrification in the primary Lithocarpus xylocarpus forest, a secondary oak forest and a tea plantationin the Ailao Mountain, Yunnan Province, China. This study was conducted in the dry season fromNovember 20, 1998 to May 15, 1999. Results showed that there were significant differences among thethree vegetation types in both net N mineralization and nitrification rates, and they also demonstratedtemporal variation. The net ammonification rate (RA) was much higher than net nitrification rate (RN), andthe latter was about 0.5%-10% of the former. Our results indicated that incubation period, vegetation typeand the location of plot all interactively affected RA, RN and net mineralization rate (RM). We providedevidence that anthropogenic disturbances could result in changes of ecosystems processes such as Nmineralization and nitrification rates. It is obvious that tea plantation and secondary growth forest havemore physically (mainly temperature and moisture) controlled N transformation processes than thewell-preserved primary L. xylocarpus forest, implying that the conservation of primary forest ecosystemsin the Ailao Mountain region should be emphasized.

关键词：木果柯林净氮矿化率净氨化率净氮硝化率哀牢山栎类次生林人工茶叶地

Differential Responses of N：P Stoichiometry of Leymus chinensis and Carex korshinskyi to N Additions in a Steppe Ecosystem in Nei Mongol

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Botanica Sinica 2004年第3期46卷 259-270页

作者： ZHANGLi-Xia BAIYong-Fei hanxing-guo LaboratoryofQuantitativeVegetationEcology InstituteofBotanyTheChineseAcademyofSciencesBeijing100093China

The typical steppe ecosystems in China are now being increasingly degraded due mainly toovergrazing. To determine the limiting nutrients is of significance in order to find out ways of successfullyrestoring the degraded steppe. In addition to field fertilization experiments, N:P stoichiometry is an alternative,but argumentative tool to study nutrient limitation. In this study, we used these two approaches to identifythe most limiting nutrient element at the species level. Furthermore, nutrient addition experimentprovides an effective means to test our hypothesis that N:P stoichiometry will remain constant becauserelatively narrow range of N:P ratio in tissues of the terrestrial plants is an important adaptive mechanismfor plants to survive on earth. For these purposes, we designed a field experiment to examine theresponses of biomass and N:P stoichiometry of the two dominant species -- Leyrnus chinensis (Trin.)Tzvel. and Carex korshinskyiKom. -- to N fertilization at rates of O, 5, 15, 30, 50 and 80 g NH4NO3.m-2.a-~in two adjacent sites, one being excluded animal grazing for 22 years (site A), and another being free ofgrazing for only two years (site B) before the experiment was carried out. No effects of N fertilization weredetected in the first year as reflected by the aboveground biomass and P concentrations of the twospecies. The regression analysis showed that N:P ratios of two species of both sites remained constant inthe second year. N fertilization significantly increased the N concentrations of two species in both years,while only significantly increased the P contents of the two species in the second year. N and P contentsof the two species were significantly correlated in all cases in 2001. Our results suggest that theL. chinensis was in short of N in site B while the growth of C. korshinskyi was limited by P in site A, andthere is a significant synergistic relationship between tissue N and P concentrations in 2001. Our hypothesiswas valid on the species

关键词：内蒙古草原生态系统 N素养分添加生物量羊草黄囊苔草

Biogenic VOCs emission inventory development of temperate grassland vegetation in Xilin River Basin, Inner Mongolia, China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第6期16卷 1024-1032页

作者： HENian-peng hanxing-guo SUNWei PanQing-min LaboratoryofQuantitativeVegetationEcology InstituteofBotanyChineseAcademyofSciencesBeijing100093China.

Given the key role of biogenic volatile organic compounds(VOCs) to tropospheric chemistry and regional air quality, it is important to generate accurate VOCs emission inventories. However, only a less fraction of plant species, in temperate grassland of Inner Mongolia, has been characterized by quantitative measurements. A taxonomic methodology, which assigns VOCs measurements to unmeasured species, is an applicable and inexpensive alternation for extensive VOCs emission survey, although data are needed for additional plant families and genera to further validate the taxonomic approach in grassland vegetation. In this experiment, VOCs emission rates of 178 plant species were measured with a portable photoionization detector(PID). The results showed the most of genera and some families have consistent feature of their VOCs emission, especially for isoprene, and provide the basic premise of taxonomic methodology to develop VOCs emission inventories for temperate grassland. Then, the taxonomic methodology was introduced into assigning emission rate to other 96 species, which no measured emission rates available here. A systematical emission inventory of temperate grassland vegetation in Inner Mongolia was provided and further evidence that taxonomy relationship can serve as a useful guide for generalizing the emissions behavior of many, but not all, plant families and genera to grassland vegetation.

关键词： VOCs PID biogenic emission isoprene monoterpene grassland vegetation taxonomic methodology

Long-term impacts of land-use change on dynamics of tropical soil carbon and nitrogen pools

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第2期16卷 256-261页

作者： YANGJing-cheng HUANGJian-hui PANQing-min TANGJian-wei hanxing-guo LaboratoryofQuantitativeVegetationEcology InstituteofBotanyChineseAcademyofSciencesBeijing100093China. XishuangbannaTropicalBotanicalGarden ChineseAcademyofSciencesMengla666303China

Land-use changes, especially the conversion of native forest vegetation to cropland and plantations in tropical region, can alter soil C and N pools and N availability for plant uptake. Deforestation, followed by shifting cultivation and establishment of rubber tree plantation, is a common land-use change in Xishuangbanna, southwest China. However the influence of this kind of land-use change on soil C and N dynamics in this region remains poorly understood. This study was conducted to assess the effects of land-use change on soil C and N pools. Soil samples were collected on five adjacent plots, which belong to three land-use types including secondary forest-an acuminate banana(Musa itinerans) secondary forest and a male bamboo(Dendrocalamus membranaceae) secondary forest, shifting cultivation, and rubber tree (Hevea brasiliensis (H.B.K.) Muell. Arg.) plantation(one plot is 3-year-old, and another is 7-year-old). We measured soil bulk density (BD), pH value, moisture content and concentrations of soil organic carbon(SOC), total soil nitrogen(TSN), and inorganic N(NO - 3-N and NH + 4-N ) at 0—3, 3—20, 20—40 and 40—60 cm depths, and calculated C and N pools in 0—20, 20—40, 40—60, and 0—60 cm soil layers. Compared with the adjacent secondary forests, shifting cultivation and establishment of rubber tree plantations resulted in significant decline in concentrations and stocks of SOC and TSN in 0—20 and 0—60 cm soil layers, and increase in pH and bulk density at 0—3, 3—20, and 20—40 cm depths. Soil moisture content decreased only in 0—20 cm surface soils in shifting cultivation and plantations. The dynamics of mineral N was much more complex, which had different trends among depths and ecosystems. Compared with the secondary forests, SOC stocks in 0—20 cm surface soils in shifting cultivation and rubber tree plantations(3-year-old plantation and 7-year-old plantation) decreased by 34.0%, 33%, and 23%; and TSN stocks decreased by 32 2%, 20.4%, and 20.4%, respect

关键词： soil organic carbon(SOC) total soil nitrogen(TSN) inorganic nitrogen land-use change tropical soil Xishuangbana

Effects of Simulated Grazing Pattern and Nitrogen Supply on Plant Growth in a Semiarid Region of Northern China

在线全文

学校读者我要写书评

暂无评论

Acta Botanica Sinica 2004年第9期46卷 1032-1039页

作者： YUANZhi-You LILing-Hao hanxing-guo JIANGFeng-He LINguo-Hui ZHAOMing-Xu RENLi-Yun LaboratoryofQuantitativeVegetationEcology InstituteofBotanyTheChineseAcademyofSciencesBeijing100093China GrasslandManagementStationofDuolunCountyDuolun027300 NeiMongolChina AnimalHusbandryBureauofTaipusi Taipusi027000NeiMongolChina

Grazing in grassland ecosystems affects plant growth by removing biomass and depositing excretal nutrients. However, grazing is not uniformly distributed in space. The spatial pattern of defoliation and excretion deposition by herbivores across vegetation mosaics has been frequently discussed, but rarely spatially quantified. A 60-day field experiment in a native semiarid grassland community was conducted to examine the responses of plant growth to simulated grazing pattern and varying nitrogen *** were subjected to five defoliation treatments determined by circularly clipped patches of different size (0, 10, 20, 40, 80cm in radius), and four nitrogen supply levels in soils (0, 5, 10, 20g N/m^2). It was detected that defoliation had reduced primary productivity by 41.5% whereas fertilization had increased it by 57.8%. The negative effect of defoliation was greater in the smallest, fertilized patches. N addition had been found to have altered the effect of defoliation, as plants growing at higher nitrogen levels were more negatively affected by defoliation than plants with no supplementary application of nitrogen. These results indicated that the magnitude of defoliation response for an individual plant was modulated by not only defoliation itself, but also other factors, such as nutrient availability, The increase in the ratio of live to dead plant parts suggested that urine deposition delayed the senescence of plants. The results also showed that (1) the effect of defoliation on primary productivity was affected by the patch size, and (2) nitrogen addition (simulated urine deposition) could increase primary productivity and affect the response to defoliation more obviously in the smaller patches than in the larger ones.

关键词：氮半干旱地区中国北方地区放牧牧场施肥植物生长

Mobilization　of　Phosphorus　by　Naturally　Occurring　Or－ganic　Acids　in　Oxisols　and　Ultisols

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 1995年第4期5卷 289-303页

作者： hanxing－guo C.F.JORDAN 等 CenterofPlantEcology InstituteofBotanyChineseAcademyofSciences141XiwaiStreetBeijing100044China In

ＭｏｂｉｌｉｚａｔｉｏｎｏｆＰｈｏｓｐｈｏｒｕｓｂｙＮａｔｕｒａｌｌｙＯｃｃｕｒｒｉｎｇＯｒ－ｇａｎｉｃＡｃｉｄｓｉｎＯｘｉｓｏｌｓａｎｄＵｌｔｉｓｏｌｓＨＡＮＸＩＮＧ－ＧＵＯａｎｄＣ．Ｆ．ＪＯＲＤＡＮ（Ｃｅｎｔｅｒ... 详细信息

ＭｏｂｉｌｉｚａｔｉｏｎｏｆＰｈｏｓｐｈｏｒｕｓｂｙＮａｔｕｒａｌｌｙＯｃｃｕｒｒｉｎｇＯｒ－ｇａｎｉｃＡｃｉｄｓｉｎＯｘｉｓｏｌｓａｎｄＵｌｔｉｓｏｌｓＨＡＮＸＩＮＧ－ＧＵＯａｎｄＣ．Ｆ．ＪＯＲＤＡＮ（ＣｅｎｔｅｒｏｆＰｌａｎｔＥｃｏｌｏｇｙ，Ｉｎ...

关键词：氧化土老成土酸性土壤天然有机酸磷代谢土壤磷

Effects of Temperature and Several Chemicals on Metabolic Changes During Dormancy Release in NJ72 Nectarine

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2003年第5期2卷 549-555页

作者： YUANZhi-you LIXian-li LILing-hao hanxing-guo YANTian-li LaboratoryofQuantitativeVegetationEcology InstituteofBotanyTheChineseAcademyofSciencesBeijing100093 HorticulturalCollegeofShandongAgriculturalUniversity Tai‘an271018P.R.China

Poor, delayed and ununiform budbreak is a major problem for peaches in greenhouse. To clarify the mechanism of breaking bud dormancy in nectarines, the effect of temperature and three dormancy-breaking agents on metabolic changes during dormancy release in two-year old NJ72 nectarine (Prunus persica L. Batch) was investigated. The result showed temperature and chemicals affected the budbreak and the metabolism of NJ72 nectarine during dormancy. Endogeneous peroxide content in buds increased soon after low temperature treatment. Meanwhile, catalase activity was also shown to increase significantly at low temperature treatment, coincided with increase of the activity of peroxidase and superoxide dismutase. The rate of respiration in flower buds increased at low temperature during dormancy. The rate of the pentose phosphate pathway increased, while the rate of the Embden-Meyerhof pathway decreased and the rate of tricarboxlic acid cycle changed little. Glucose 6-phosphate dehydrogenase activity increased at low temperature during dormancy. At the same time we found an accumulation of peroxide after treatment with dormancy-breaking chemicals. In flower buds treated with dormancy-breaking agents, thiourea, KNO3 and NH4NO3, catalase activity was inhibited soon after treatment, whereas peroxidase activity increased, and the changes of superoxide dismutase remained little. In this study, it was found that the rates of respiration in flower buds increased by chemicals sprays during dormancy. The activity of glucose 6-phosphate dehydrogenase, the key enzyme in the pentose phosphate pathway (PPP), increased by spraying with dormancy-breaking agents, concomitantly with the activation of the pentose phosphate pathway.

关键词： Prunus persica L. Batch Dormancy Temperature Chemicals

Soil Phosphorus Dynamics as Influenced by Land Use Changes in Humid Tropical, Southwest China

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2005年第1期15卷 24-32页

作者： YANGJing-Cheng HUANGJian-Hui PANQing-Min TANGJian-Wei hanxing-guo LaboratoryofQuantitativeVegetationEcology InstituteofBotanyChineseAcademyofSciencesBeijing1000g3China LaboratoryofQuantitativeVegetationEcology InstituteofBotanyChineseAcademyofSciencesBeijing1000g3China／／BeijingNaturalHistoryMuseumBeijing100050China XishuangbannaTropicalBotanicalGarden ChineseAcademyofSciencesYunnan666303China

Land use changes can greatly influence soil phosphorus (P) dynamics, especially when converting native forests to agricultural land. Soils in Xishuangbanna, which is one of southwest China's tropical areas that maintain fragments of primary forests, were studied to a) evaluate the effect of two common land use changes, conversion of forests to agricultural land or rubber tree plantation, on the dynamics of available P and total P in bulk soils as well as total P in particle size fractions; b) assess the relationship between soil P dynamics and soil organic carbon (SOC); and c)elucidate the relationship between soil P content and soil properties such as pH and texture. Clearing secondary forests with subsequent shifting cultivation and establishment of rubber tree plantation caused significant decreases (P ＜ 0.05)in available P at 0-20 cm soil depths, whereas for total P there was a significant decrease (P ＜ 0.05) when converting to shifting cultivation, rubber tree plantation, or fallow field at both 0-20 and 20-40 cm depths. Abandonment of fields used for shifting cultivation led to significant increases (P ＜ 0.05) in available P at 20-40 cm depth. In addition, there was a significant positive relationship between soil organic carbon and soil P content. Compared to secondary forests, the ratio of organic carbon to total P in surface soils (0-20 cm) of shifting cultivation and rubber tree plantation was significantly lower (P ＜ 0.05).

关键词：土壤化学磷动力学颗粒尺寸橡胶树种植条件

Plateau Marsh Methane Oxidation as affected by Inorganic N

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2004年第2期14卷 195-204页

作者： WANGZhi-Ping DUANYi YANGJu-Rong LILing-Hao hanxing-guo LaboratoryofQuantitativeVegetationEcology InstituteofBotanyChineseAcademyofSciencesBeijing100093（China）／E-mail：wangzp5@*** StateKeyLaboratoryofGasGeochemistry LanzhouInstituteofGeology.ChineseAcademyofSciencesLanzhou730000（China） CollegeofResourceandEnvironment BEijingNormailUniversityBeijing100875（China）

In a series of laboratory incubations using soils of two contrasting sites from a temperate marsh on the QinghaiTibet Plateau,potential methane (CH4) oxidation rates were measured to study the effects of inorganic N inputs on CH4 oxidation. For a drained site,subsurface peat (5-15 cm) at an initial 20 μL CH4 L-1 showed a significantly different (P＜0.05) CH4 oxidation rate compared to other soil depths,with a maximal rate of 20.9 ng CH4 gDW (dry weight)-1h-1; the underlying mineral soil layers (15-30 and 30-50 cm) also had a strong CH4 oxidation capacity at about an initial 2000 μL CH4 L-1. With a waterlogged site,the CH4 oxidation rate in an aerobic incubation was significantly greater (P＜0.05) in the surface soil layer (0-5cm) compared to the 15-30 and 30-50 cm depths. There was generally no or a very weak effect from addition of NO3- on CH4 oxidation. In marked contrast,NH4+ salts,such as (NH4)2SO4,NH4C1 and NH4NO3,exhibited strong inhibitions,which varied as a function of the added salts and the initial CH4 level. Increasing NH4+ usually resulted in greater inhibition and increasing initial CH4 concentrations resulted in less. NH4+ inhibition on CH4 oxidation in natural high-altitude,low-latitude wetlands could be as important as has been reported for agricultural and forest soils. The NH4+ effects on the CH4 oxidation rate need to be further investigated in a wide range of natural wetland soil types.

关键词：沼气湿地氧化无机物氮

在线全文

学校读者我要写书评

暂无评论

圈养与野生川金丝猴应激水平的比较研究

野生动物学报 2022年第3期43卷 623-628页

作者：王炎王娟娟杨静郭含星罗伟强王晓卫严兴荣陕西省动物研究所西安710032 陕西省野生动物保育重点实验室西安710043 西北大学生命科学学院西安710127 空军军医大学西京医院实验动物中心西安710032

为进一步探索川金丝猴(Rhinopithecus roxellana)应激水平和生殖激素的变化,以川金丝猴的粪便为试验材料,提取粪便中的肠道上皮细胞RNA和内固醇激素,检查样本皮质醇、睾酮和孕酮水平。结果显示:圈养(n=30)和野生(n=45)川金丝猴中,仅从3... 详细信息

为进一步探索川金丝猴(Rhinopithecus roxellana)应激水平和生殖激素的变化,以川金丝猴的粪便为试验材料,提取粪便中的肠道上皮细胞RNA和内固醇激素,检查样本皮质醇、睾酮和孕酮水平。结果显示:圈养(n=30)和野生(n=45)川金丝猴中,仅从3只圈养川金丝猴的粪便中提取出了RNA;圈养川金丝猴皮质醇质量分数显著高于野生川金丝猴(P<0.05);圈养雌性川金丝猴皮质醇和孕酮质量分数显著高于野生雌性川金丝猴(P<0.01);圈养成年雄性川金丝猴皮质醇和睾酮质量分数显著高于野生雄性川金丝猴(P<0.05)。说明圈养川金丝猴应激水平、睾酮和孕酮质量分数高于野生个体,结果可为后续川金丝猴的繁育研究奠定理论和实践基础。

关键词：川金丝猴粪便皮质醇孕酮睾酮 RNA