检索结果-南通市图书馆

Soil respiration is driven by fine root biomass along a forest chronosequence in subtropical China

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2017年第1期10卷 36-46页

作者： Chao Wang Yinlei Ma Stefan Trogisch Yuanyuan Huang Yan Geng Michael Scherer-Lorenzen Jin-Sheng He Department of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University5 Yiheyuan RoadBeijing 100871China Department for Geobotany Institute of Biology/Geobotany and Botanical GardenMartin-Luther-University Halle-WittenbergAm Kirchtor 1Halle(Saale)D-06108Germany German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5eLeipzig D-04103Germany Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences12 Zhongguancun South StreetBeijing 100081China Faculty of Biology/Geobotany University of Freiburg79104 FreiburgGermany

Aims Soil respiration(Rs)is a major process controlling soil carbon loss in forest ***,the underlying mechanisms leading to variation in Rs along forest successional gradients are not well *** this study,we investigated the effects of biotic and abiotic factors on Rs along a forest successional gradient in southeast *** We selected 16 plots stratified by forest age,ranging from 20 to 120 *** each plot,six shallow collars and six deep collars were permanently inserted into the *** and deep collars were used to measure Rs and heterotrophic respiration(Rh),*** soil respiration(Ra)was estimated as the difference between Rs and *** layer respiration(R_(L))was calculated by subtracting soil respiration measured in collars without leaf litter layer(R_(NL))from *** was measured every 2 months,and soil temperature(ST)and soil volumetric water content(SVWC)were recorded every hour for 19 *** calculated daily Rs using an exponential model dependent on *** Rs was summed to obtain cumulative annual Rs *** equation modelling(SEM)was applied to identify the drivers of Rs during forest *** Findings Rs showed significant differences among three successive stages,and it was the highest in the young *** was higher in the young stage than in the medium *** annual Rs and Ra peaked in the young and old stages,*** annual Rh and respiration measured from soil organic matter(R_(SOM))decreased,whereas R_(L)increased with forest *** SEM revealed that cumulative annual Rs was influenced by fine root biomass and *** results indicated that the dominant force regulating Rs on a seasonal scale is ST;however,on a successional scale,belowground carbon emerges as the dominant influential factor.

关键词： forest succession soil respiration fine root biomass soil temperature

Seasonal dynamics of fine root biomass, root length density, specific root length, and soil resource availability in a Larix gmelinii plantation

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

Frontiers in Biology 2006年第3期1卷 310-317页

作者： CHENG Yunhuan HAN Youzhi WANG Qingcheng WANG Zhengquan School of Forestry Northeast Forestry UniversityHarbin 150040China School of Forestry Shanxi Agricultural UniversityTaigu 030801China

fine root turnover is a major pathway for carbon and nutrient cycling in terrestrial ecosystems and is most likely sensitive to many global change *** the importance of fine root turnover in plant C allocation and nutrient cycling dynamics and the tremendous research efforts in the past,our understanding of it remains *** is because the dynamics processes associated with soil resources availability are still poorly *** moisture,temperature,and available nitrogen are the most important soil characteristics that impact fine root growth and mortality at both the individual root branch and at the ecosystem *** temperate forest ecosystems,seasonal changes of soil resource availability will alter the pattern of carbon allocation to ***,fine root biomass,root length density(RLD)and specific root length(SRL)vary during the growing *** seasonal changes of fine root biomass,RLD,and SRL associated with soil resource availability will help us understand the mechanistic controls of carbon to fine root longevity and *** objective of this study was to understand whether seasonal variations of fine root biomass,RLD and SRL were associated with soil resource availability,such as moisture,temperature,and nitrogen,and to understand how these soil components impact fine root dynamics in Larix gmelinii *** used a soil coring method to obtain fine root samples(≤2 mm in diameter)every month from May to October in 2002 from a 17-year-old *** plantation in Maoershan Experiment Station,Northeast Forestry University,***-two soil cores(inside diameter 60 mm;depth intervals:0-10 cm,10-20 cm,20-30 cm)were sampled randomly from three replicates 25 m×30 m plots to estimate fine root biomass(live and dead),and calculate RLD and *** moisture,temperature,and nitrogen(ammonia and nitrates)at three depth intervals were also analyzed in these *** showed that the average standing fine ro

关键词： Larix gmelinii fine root biomass root length density specific root length soil resource availability seasonal dynamics

Spatial heterogeneity of fine root biomass of Pinus massoniana forests in the Three Gorges Reservoir Area, 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

Forestry Studies in China 2013年第1期15卷 13-23页

作者： Rui-Li WANG Rui-Mei CHENG Wen-Fa XIAO Xiao-Hui FENG Ze-Bin LIU Xiao-Rong WANG Zhi-Bo WANG Key Laboratory of Forest Ecology and Environment of State Forestry Administration Research Institute of Forest Ecology Environment and Protection Chinese Academy of Forestry Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Hubei Forestry Academy Research Institute of Forest Resource Information Techniques Chinese Academy of Forestry

Environmental heterogeneity is a constant presence in the natural world that significantly affects plant behavior at a variety of levels of complexity. In order to estimate the spatial pattern of fine root biomass in the Three Gorges Reservoir Area, the spatial heterogeneity of fine root biomass in the upper layer of soils （0-10 cm） in three Mas- son pine （Pinus massoniana） stands in the Three Gorges Reservoir Area, China, was studied in 30 m x 30 m plots with geostatistical analysis. The results indicate that 1） both the live and dead fine root biomass of stand 2 were less than those of other stands, 2） the spatial variation of fine roots in the three stands was caused together by structural and ran- dom factors with moderate spatial dependence and 3） the magnitude of spatial heterogeneity of live fine roots ranked as： stand 3 〉 stand 1 〉 stand 2, while that of dead fine roots was similar in the three stands. These findings suggested that the range of spatial autocorrelation for fine root biomass varied considerably in the Three Gorges Reservoir Area, while soil properties, such as soil bulk density, organic matter and total nitrogen, may exhibit great effect on the spatial distribution of fine roots. Finally, we express our hope to be able to carry out further research on the quantitative relation- ship between the spatial heterogeneous patterns of plant and soil properties.

关键词： spatial heterogeneity geostatistics Pinus massoniana fine root biomass Three Gorges Reservoir Area

Contrasting changes in above- and below-ground biomass allocation across treeline ecotones in southeast Tibet

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2016年第11期13卷 2036-2045页

作者： Liu Xin-sheng Nie Yu-qin Kong Gao-qiang Luo Tian-xiang College of Tourism and Territorial Resources Jiujiang University Jiujiang 332005 China Key Laboratory of Alpine Ecology and Biodiversity Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100101 China School ofAccountancy Jiujiang University Jiujiang 332005 China

Under conditions of a warmer climate,the advance of the alpine treeline into alpine tundra has implications for carbon dynamics in mountain ***,the above- and below-ground live biomass allocations among different vegetation types within the treeline ecotones are not well *** determine the altitudinal patterns of above-/below-ground carbon allocation,we measured the root biomass and estimated the above-ground biomass(AGB) in a subalpine forest,treeline forest,alpine shrub,and alpine grassland along two elevational transects towards the alpine tundra in southeast *** AGB strongly declined with increasing elevation,which was associated with a decrease in the leaf area index and a consequent reduction in carbon *** fine root biomass(FRB) increased significantly more in the alpine shrub and grassland than in the treeline forest,whereas the coarse root biomass changed little with increasing altitudes,which led to a stable below-ground biomass(BGB) value across *** and infertile soil conditions might explain the large amount of FRB in alpine shrub and ***,the root toshoot biomass ratio increased sharply with altitude,which suggested a remarkable shift of biomass allocation to root systems near the alpine *** findings demonstrate contrasting changes in AGB and BGB allocations across treeline ecotones,which should be considered when estimating carbon dynamics with shifting treelines.

关键词： Treeline ecotone fine root biomass Above-ground biomass Vegetation type Southeast Tibet

Soil-nitrogen net mineralization increased after nearly six years of continuous nitrogen additions in a subtropical bamboo ecosystem

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2015年第4期26卷 949-956页

作者： Yin-long Xiao Li-hua Tu Gang Chen Yong Peng Hong-ling Hu Ting-xing Hu Li Liu College of Forestry Sichuan Agricultural University Personnel Department Sichuan Agricultural University

In order to understand the effects of increasing atmospheric nitrogen （N） deposition on the subtropical bamboo ecosystem, a nearly six-year field experiment was conducted in a Pleioblastus amarus plantation in the rainy region of SW China, near the western edge of Sichuan Basin. Four N treatment levels---control （no N added）, low- N （50 kg N ha-1 a-l）, medium-N （150 kg N ha-1 a-l）, and high-N （300 kg N ha-1 a-1）--were applied monthly in the P. amarus plantation starting in November 2007. In June 2012, we collected intact soil cores in the bamboo plantation and conducted a 30-day laboratory incubation experiment. The results showed that the soil N net miner- alization rate was 0.96 4- 0.10 mg N kg-1 day-1, under control treatment. N additions stimulated the soil N net mineralization, and the high-N treatment significantly increased the soil N net mineralization rate compared with the control. Moreover, the soil N net mineralization rate was significantly and positively correlated with the fine root biomass, the soil microbial biomass nitrogen content and the soil initial inorganic N content, respectively,whereas it was negatively correlated with the soil pH value. There were no significant relationships between the soil N net mineralization rate and the soil total nitrogen （TN） content and the soil total organic carbon content and the soil C/N ratio and the soil microbial biomass carbon con- tent, respectively. These results suggest that N additions would improve the mineral N availability in the topsoil of the P. amarus plantation through the effects of N additions on soil chemical and physical characteristics and fine-root biomass.

关键词： Nitrogen addition Soil nitrogen net mineralization Soil chemical and physical characteristics fine root biomass Pleioblastus amarus plantation