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| 1 | Observation and modeling of NPP for Pinus elliottii plantation in subtropical China显示文摘Based on the stem analysis of 59 individuals of Pinus elliottii in combination with tree biomass models, we calculated annual biomass increment of forest plots at Qianyanzhou Ecological Station, Chinese Academy of Sciences in subtropical China. In addition, canopy layer and community NPP were calcu- lated based on 12 years’ litter fall data. NPP of the 21-year-old forest was estimated by using the BIOME BGC model; and both measured NPP and estimated NPP were compared with flux data. Community biomass was 10574 g·m-2; its distribution patterns in tree layer, shrub layer, herbaceous layer, tree root, herbaceous and shrub roots and fine roots were 7542, 480, 239, 1810, 230, 274 and 239 g·m-2, respectively. From 1999 to 2004, the average annual growth rate and litter fall were 741 g·m-2·a-1 (381.31 gC·m-2·a-1) and 849 g·m?2·a?1 (463 gC·m-2·a-1), respectively. There was a significant corre- lation between annual litter fall and annual biomass increment; and the litter fall was 1.19 times the biomass increment of living trees. From 1985 to 2005, average NPP and GPP values based on BGC modeling were 630.88 (343.31 - 906.42 gC·m-2·a-1) and 1 800 gC·m-2·a-1 (1351.62 - 2318.26 gC·m-2·a-1). Regression analysis showed a linear relationship (R2=0.48) between the measured and simulated tree layer NPP values. NPP accounted for 30.2% (25.6%-32.9%) of GPP, while NEP ac- counted for 57.5% (48.1%-66.5%) of tree-layer NPP and 41.74% (37%-52%) of stand NPP. Soil respi- ration accounted for 77.0% of measured tree NPP and 55.9% of the measured stand NPP. NEE based on eddy covariance method was 12.97% higher than the observed NEP. | MA ZeQing LIU QiJing WANG HuiMin LI XuanRan ZENG HuiQing XU WenJia | 2008 | Science China Earth Sciences2008，51，7： | 9 |
| 2 | Resistance of strains producing extended-spectrum β-lactamases and genotype distribution in China显示文摘 | Yunsong Yu Shujuan Ji Yagang Chen Weilin Zhou Zeqing Wei Lanjuan Li Yilin Ma | 2006 | Journal of Infection2006，，1： | 1 |
| 3 | The 2/3 scaling of twig nitrogen to phosphorus in woody plants显示文摘Background:Nitrogen(N)and phosphorus(P)are important elements for plant metabolism and growth.Therefore,the quantification of the scaling relationship of N to P in plant organs can help us understand many fundamental ecological processes.The general scaling relationships between N and P in leaves and in fine roots have been reported.As compared to leaves and fine roots,however,little information is available on the N versus P scaling relationship in the stems of woody plants,especially for twigs.In this study,a comprehensive dataset comprising 2,038 N=P paired observations for a total of 536 woody species was compiled and analyzed to determine whether a general scaling relationship exists.Results:The global mean values of twig N and P concentrations and N:P ratios were 9.33 mg⋅g^(-1),1.12 mg⋅g^(-1) and 10.16,respectively.Twig N and P concentrations and N:P ratios differed significantly within and across functional groups and biomes.Across all of the species,a uniform 0.67 scaling exponent of twig N to P was observed across different functional groups and biomes,i.e.,a 2/3-power scaling relationship was observed.However,this numerical value differed across different sites,albeit converging onto 0.67 with increasing sample sizes.Soil total phosphorus was the largest contributor to the variation in the numerical value of the scaling exponent.Conclusion:These results provide useful parameters for stoichiometric growth models,and advance our understanding of the mechanisms underlying plant nutrient dynamics.This study has potential implications in predicting responses of nutrient cycling in terrestrial ecosystem responses to changes in the environment. | Zhiqiang Wang Karl JNiklas Zeqing Ma Dechun Jiang Jianming Deng | 2022 | Forest Ecosystems2022，9，4： | 0 |
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