作者机构：
[Tian, Dalun; Peng, Xinsha] Cent South Univ Forestry Sci & Technol, Sch Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.
会议名称：
International Conference on Low-carbon Transportation and Logistics, and Green Buildings (LTLGB)
会议时间：
OCT 12-13, 2012
会议地点：
Beijing Jiaotong Univ, Beijing, PEOPLES R CHINA
会议主办单位：
Beijing Jiaotong Univ
关键词：
Changsha-ZhuZhou-Xiangtan urban agglomeration;Pilot zone of two-oriented society;Construction of low carbon cities;Progresses;Experience;Case study
摘要：
Low carbon cities construction is an important content and pointcut of "Two-oriented society'' construction. Since Chang-Zhu-Tan urban agglomeration was authorized to be "Two-oriented society'' pilot zone by the State Council in December, 2007, Chang-Zhu-Tan Low Carbon urban agglomeration has achieved remarkable progresses and accumulated precious experience which is necessary to summarize comprehensively and systematically to provide effective strategies for the development in next step. Three aspects of contents are presented in this paper. Firstly, four major progresses of Chang-Zhu-Tan Low Carbon urban agglomeration have been summarized systematically. Secondly, successful experiences in five aspects are summarized. Lastly, three main conclusions are concluded.
通讯机构：
[Xiang, Wenhua] C;Cent S Univ Forestry & Technol, Fac Life Sci & Technol, Changsha, Hunan, Peoples R China.
关键词：
Forests;Forest ecology;Wood;Trees;Biomass (ecology);Ecosystems;Productivity (ecology);Simulation and modeling
摘要：
Cunninghamia lanceolata (Lamb.) Hook. has been widely planted in subtropical China to meet increasing timber demands, leading to short-rotation practices that deplete soil nutrients. However, increased nitrogen (N) deposition offsets soil N depletion. While long-term experimental data investigating the coupled effects related to short rotation practices and increasing N deposition are scarce, applying model simulations may yield insights. In this study, the CenW3.1 model was validated and parameterized using data from pure C. lanceolata plantations. The model was then used to simulate various changes in long-term productivity. Results indicated that responses of productivity of C. lanceolata plantation to increased N deposition were more related to stand age than N addition, depending on the proportion and age of growing forests. Our results have also shown a rapid peak in growth and N dynamics. The peak is reached sooner and is higher under higher level of N deposition. Short rotation lengths had a greater effect on productivity and N dynamics than high N deposition levels. Productivity and N dynamics decreased as the rotation length decreased. Total productivity levels suggest that a 30-year rotation length maximizes productivity at the 4.9 kg N ha−1 year−1 deposition level. For a specific rotation length, higher N deposition levels resulted in greater overall ecosystem C and N storage, but this positive correlation tendency gradually slowed down with increasing N deposition levels. More pronounced differences in N deposition levels occurred as rotation length decreased. To sustain C. lanceolata plantation productivity without offsite detrimental N effects, the appropriate rotation length is about 20–30 years for N deposition levels below 50 kg N ha−1 year−1 and about 15–20 years for N deposition levels above 50 kg N ha−1 year−1. These results highlight the importance of assessing N effects on carbon management and the long-term productivity of forest ecosystems.
期刊：
Australian Journal of Botany,2011年59(1):26-31 ISSN：0067-1924
通讯作者：
Chen, Xiaoyong
作者机构：
[Tian, Dalun; Wang, Guangjun; Yan, Wende; Fang, Xi; Zhu, Fan] Cent S Univ Forestry & Technol, Fac Life Sci & Technol, Forest Ecol Program, Changsha 410004, Hunan, Peoples R China.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, Div Sci, University Pk, IL 60484 USA.;[Tian, Dalun; Wang, Guangjun; Yan, Wende; Fang, Xi; Zhu, Fan] Natl Engn Lab Appl Forest Ecol Technol So China, Changsha 410004, Hunan, Peoples R China.;[Peng, Yuanying] Coll DuPage, Div Nat Sci, Glen Ellyn, IL 60137 USA.
通讯机构：
[Chen, Xiaoyong] G;Governors State Univ, Coll Arts & Sci, Div Sci, University Pk, IL 60484 USA.
摘要：
Soil respiration (R-s) is overwhelmingly the sum of autotrophic respiration (R-a, root and rhizosphere) and heterotrophic respiration (R-h, microbes and soil fauna). Separating R-s into R-a and R-h components is a major challenge but necessary for understanding the implications of environmental change on soil C cycling and sequestration. In this study, a trenching method was employed to partition R-s sources in Chinese fir plantations in Southern China. Soil CO2 efflux (FCO2) rates were measured using an infrared gas analyser system with soil chambers at the trenched and untrenched (Control) plots from January 2007 to December 2008. Soil temperature (T-soil) and soil water content (W-soil) were also measured at the plots during the study period. The results showed that the mean soil FCO2 rate from trenched plots (0.88 +/- 0.12 mu mol m(-2) s(-1), mean +/- s.e.) was significantly lower than that from untrenched plots (1.22 +/- 0.18 mu mol m(-2) s(-1)) (P < 0.001) during the study period. Compared with R-a, R-h made a major contribution to annual flux ofRs in Chinese fir forests. The relative proportion of R-h to R-s averaged 76 and 69% in 2007 and 2008, respectively. The seasonal changes of R-a to R-s ratio ranged from 13 to 56% with a mean of 33%. The annual mean R-s was 455 +/- 249 gCm(-2) year(-1) in the study site for the study period, of which R-h and R-a were 330 +/- 219 and 125 +/- 65 gCm(-2) year(-1), respectively. Both R-s and R-h was strongly correlated with T-soil at a 5-cm depth, while R-a had no relationship with T-soil. Temporal variation in W-soil had little effect on R-s and R-h. The results indicated that the fluxes of R-a and R-h were controlled by different factors and the microbial communities, compared with roots, were likely more sensitive to global warming in affecting soil C fluxes in Chinese fir ecosystems in subtropical regions.
作者机构：
[Tian, Dalun; Zhao, Meifang; Liu, Shaohui; Xiang, Wenhua; Peng, Changhui; Deng, Xiangwen] Cent S Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.;[Liu, Shaohui] China State Forestry Adm, Dept Dev Planning & Assets Management, Beijing 100714, Peoples R China.;[Shen, Aihua] Zhejiang Forestry Acad, Hangzhou 310023, Zhejiang, Peoples R China.;[Lei, Xiangdong] Chinese Acad Forestry, Inst Forest Resource Informat Tech, Beijing 100091, Peoples R China.;[Peng, Changhui] Univ Quebec, Dept Biol Sci, Inst Environm Sci, Montreal, PQ H3C 3P8, Canada.
通讯机构：
[Xiang, Wenhua] C;Cent S Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.
关键词：
Pinus massoniana;Allometric equation;Tree biomass carbon;Regional scale;Southern China subtropical region
摘要：
Applying allometric equations in combination with forest inventory data is an effective approach to use when qualifying forest biomass and carbon storage on a regional scale. The objectives of this study were to (1) develop general allometric tree component biomass equations and (2) investigate tree biomass allocation patterns for Pinus massoniana, a principal tree species native to southern China, by applying 197 samples across 20 site locations. The additive allometric equations utilized to compute stem, branch, needle, root, aboveground, and total tree biomass were developed by nonlinear seemingly unrelated regression. Results show that the relative proportion of stem biomass to tree biomass increased while the contribution of canopy biomass to tree biomass decreased as trees continued to grow through time. Total root biomass was a large biomass pool in itself, and its relative proportion to tree biomass exhibited a slight increase with tree growth. Although equations employing stem diameter at breast height (dbh) alone as a predictor could accurately predict stem, aboveground, root, and total tree biomass, they were poorly fitted to predict the canopy biomass component. The inclusion of the tree height (H) variable either slightly improved or did not in any way increase model fitness. Validation results demonstrate that these equations are suitable to estimate stem, aboveground, and total tree biomass across a broad range of P. massoniana stands on a regional scale.
