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12篇 您的检索式:作者名="Xiankai Lu"
    题名 作者 年代 出处 被引量
1Climate and litter C/N ratio constrain soil organic carbon accumulation显示文摘Soil organic carbon(SOC) plays critical roles in stabilizing atmospheric CO2 concentration, but the mechanistic controls on the amount and distribution of SOC on global scales are not well understood. In turn, this has hampered the ability to model global C budgets and to find measures to mitigate climate change. Here, based on the data from a large field survey campaign with 2600 plots across China’s forest ecosystems and a global collection of published data from forested land, we find that a low litter carbon-to-nitrogen ratio(C/N) and high wetness index(P/PET, precipitation-to-potentialevapotranspiration ratio) are the two factors that promote SOC accumulation, with only minor contributions of litter quantity and soil texture. The field survey data demonstrated that high plant diversity decreased litter C/N and thus indirectly promoted SOC accumulation by increasing the litter quality. We conclude that any changes in plant-community composition, plant-species richness and environmental factors that can reduce the litter C/N ratio, or climatic changes that increase wetness index, may promote SOC accumulation. The study provides a guideline for modeling the carbon cycle of various ecosystem scales and formulates the principle for land-based actions for mitigating the rising atmospheric CO2 concentration.Guoyi Zhou Shan Xu Philippe Ciais Stefano Manzoni Jingyun Fang Guirui Yu Xuli Tang Ping Zhou Wantong Wang Junhua Yan Gengxu Wang Keping Ma Shenggong Li Sheng Du Shijie Han Youxin Ma Deqiang Zhang Juxiu Liu Shizhong Liu Guowei Chu Qianmei Zhang Yuelin Li Wenjuan Huang Hai Ren Xiankai Lu Xiuzhi Chen 2019National Science Review2019,6,4:21
2Responses of Soil Acid Phosphomonoesterase Activity to Simulated Nitrogen Deposition in Three Forests of Subtropical China显示文摘Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation. Responses of soil APA to elevating nitrogen (N) deposition are important because of their potential applications in addressing the relationship between N and P in forest ecosystems. A study of responses of soil APA to simulated N deposition was conducted in three succession forests of subtropical China. The three forests include a Masson pine (Pinus massoniana) forest (MPF)-pioneer community, a coniferous and broad-leaved mixed forest (MF)-transition community and a monsoon evergreen broad-leaved forest (MEBF)-climax community. Four N treatments were designed for MEBF: control (without N added), low-N (50 kg N ha-1 year-1), and medium-N (100 kg N ha-1 year-1) and high-N (150 kg N ha-1 year-1), and only three N treatments (i.e., control, low-N, medium-N) were established for MPF and MF. Results showed that soil APA was highest in MEBF, followed by MPF and MF. Soil APAs in both MPF and MF were not influenced by low-N treatments but depressed in medium-N treatments. However, soil APA in MEBF exhibited negative responses to high N additions, indicating that the environment of enhanced N depositions would reduce P supply for the mature forest ecosystem. Soil APA and its responses to N additions in subtropical forests were closely related to the succession stages in the forests.HUANG Wen-Juan ZHANG De-Qiang LI Yue-Lin LU XianKai ZHANG Wei HUANG Juan D.OTIENO Z.H.XU LIU Ju-Xiu LIU Shi-Zhong CHU Guo-Wei 2012Pedosphere2012,22,5:13
3Phosphorus limitation on photosynthesis of two dominant understory species in a lowland tropical forest显示文摘Aims Elevated nitrogen(N)deposition in tropical regions may accelerate ecosystem phosphorus(P)limitation.However,it is not explicitly addressed that how changes in soil N and P availability affect foliar nutrients and photosynthesis of plants in tropical forests.In this study,we examined the effects of N and P additions on foliar nutrients and net photosynthesis of two dominant understory species,Randia can-thioides(R.canthioides)and Cryptocarya concinna(C.concinna)in an N-saturated old-growth tropical forest(>400-year-old)in south-ern China.Methods A full factorial NP addition experiment(2×2)was established in 2007 and continued through August 2010.Four treatments,including control,N addition(150 kg N ha^(−1) year^(−1)),P addi-tion(150 kg P ha^(−1) year^(−1))and NP addition(150 kg N ha^(−1) year^(−1) plus 150 kg P ha^(−1) year^(−1))were set up in this experiment.Photosynthetic traits maximum photosynthetic CO_(2) assimilation(Amax),stomatal conductance(gs),leaf transpiration(E),light satu-rating point,concentrations of chlorophyll a/b and foliar nutri-ents(N and P)of the two species were measured with standard methods.Important Findings Three years of N addition had no significant effects on any measured photosynthetic parameter of either species.However,N addition significantly elevated foliar N and P concentrations of one species(R.canthioides),resulting in lower photosynthetic nitrogen use effi-ciency(PNUE).N treatments decreased foliar P concentration of the other(C.concinna),resulting in increased photosynthetic phos-phorus use efficiency,which was potentially related to N-induced P shortage.In contrast,positive effects of P treatments on gs of R.can-thioides,Amax and chlorophyll a+b of C.concinna were observed.P treatments also elevated foliar P and PNUE of both species,imply-ing P induced more efficient use of N.Our results suggested a more important role of P than N on influencing photosynthetic traits of these two understory species.Alleviation of P shortage through P addition may enhance photosynthetic performances of some under-story species in N-rich tropical forests.Feifei Zhu Xiankai Lu Jiangming Mo 2014Journal of Plant Ecology2014,7,6:10
4Nitrogen deposition and its ecological impact in China: An overview显示文摘Xuejun Liu Lei Duan Jiangming Mo Enzai Du Jianlin Shen Xiankai Lu Ying Zhang Xiaobing Zhou Chune He Fusuo Zhang 2010Environmental Pollution2010,,10:4
5Emissions of nitrous oxide from three tropical forests in Southern China in response to simulated nitrogen deposition显示文摘Wei Zhang Jiangming Mo Guirui Yu Yunting Fang Dejun Li Xiankai Lu Hui Wang 2008Plant and Soil (-)2008,,1:1
6Coarse-to-Fine Video Instance Segmentation With Factorized Conditional Appearance Flows显示文摘We introduce a novel method using a new generative model that automatically learns effective representations of the target and background appearance to detect,segment and track each instance in a video sequence.Differently from current discriminative tracking-by-detection solutions,our proposed hierarchical structural embedding learning can predict more highquality masks with accurate boundary details over spatio-temporal space via the normalizing flows.We formulate the instance inference procedure as a hierarchical spatio-temporal embedded learning across time and space.Given the video clip,our method first coarsely locates pixels belonging to a particular instance with Gaussian distribution and then builds a novel mixing distribution to promote the instance boundary by fusing hierarchical appearance embedding information in a coarse-to-fine manner.For the mixing distribution,we utilize a factorization condition normalized flow fashion to estimate the distribution parameters to improve the segmentation performance.Comprehensive qualitative,quantitative,and ablation experiments are performed on three representative video instance segmentation benchmarks(i.e.,YouTube-VIS19,YouTube-VIS21,and OVIS)and the effectiveness of the proposed method is demonstrated.More impressively,the superior performance of our model on an unsupervised video object segmentation dataset(i.e.,DAVIS19)proves its generalizability.Our algorithm implementations are publicly available at http://gffzz188fe103f8f1460as5pf05qn65nuw6cnf.ffgz.tsg.suse.edu.cn/zyqin19/HEVis.Zheyun Qin Xiankai Lu Xiushan Nie Dongfang Liu Yilong Yin Wenguan Wang 2023IEEE/CAA Journal of Automatica Sinica2023,10,5:1
7Effects of experimental nitrogen additions on plant diversity in an old-growth tropical forest显示文摘Lu Xiankai Mo Jiangming Gilliam F S 2010Global Change Biology2010,16,10:1
8Effects of experimental nitrogen additions on plant diversity in tropical forests of contrasting disturbance regimes in Southern China显示文摘Lu Xiankai Mo Jiangming Gilliam F S 2011Environmental Pollution2011,159,10:1
9Effects of experimental nitrogen additions on plant diversity in an old-growth tropical forest显示文摘LU Xiankai MO Jiangming GILL1AM F S 2010Global Change Biology2010,16,10:1
10Dynamic traveling time forecasting based on spatial-temporal graph convolutional networks显示文摘1 Introduction Traveling time forecasting,the core component in GPS navigation systems and taxi-hailing apps,has attracted widespread attention.Existing research mostly focuses on independent points like traffic flow prediction[1,2]or route planning[3,4],which ignore globality and lack satisfactory dynamic progress to adopt sophisticated traffic conditions.To facilitate this line of research,we propose a novel Dynamic Traveling Time forecasting framework based on the Spatial and Temporal Graph convolution(DTT-STG)integrated with map-matching,road speed forecasting,and route planning with full consideration of the dynamic spatial and temporal dependency.DTT-STG designs an angle-based map-matching algorithm to describe the direction of vehicles and explores a self-adaptive adjacency matrix combined with diffusion convolution and attention mechanisms to capture the dynamically changing spatial-temporal dependencies.Afterward,the progressive method is exploited to calculate the traveling time and plan the shortest route dynamically in continuously changing traffic states.Fangshu CHEN Yufei ZHANG Lu CHEN Xiankai MENG Yanqiang QI Jiahui WANG 2023Frontiers of Computer Science2023,17,6:0
11Fine root litter quality regulates soil carbon storage efficiency in subtropical forest soils显示文摘●High-quality and low-quality root litter had contrasting patterns of mass loss.●Greater litter-derived C was incorporated into soils under high-quality root litter.●Root litter decay rate or litter-derived C were related to soil microbial diversity.●Root litter quality had little effect on soil physicochemical properties.●High root litter quality was the main driver of enhanced soil C storage efficiency.Decomposing root litter is a major contributor to soil carbon(C)storage in forest soils.During decomposition,the quality of root litter could play a critical role in soil C storage.However,it is unclear whether root litter quality influences soil C storage efficiency.We conducted a two-year greenhouse decomposition experiment using 13C-labeled fine root litter of two tree species to investigate how root litter quality,represented by C to nitrogen(C/N)ratios,regulates decomposition and C storage efficiency in subtropical forest soils in China.‘High-quality’root litter(C/N ratio=26)decayed faster during the first year(0−410 days),whereas‘low-quality’root litter(C/N ratio=46)decomposed faster toward the end of the two-year period(598−767 days).However,over the two years of the study,mass loss from high-quality root litter(29.14±1.42%)was lower than‘low-quality’root litter(33.01±0.54%).Nonetheless,root litter C storage efficiency(i.e.,the ratio of new root litter-derived soil C to total mineralized root litter C)was significantly greater for high-quality root litter,with twice as much litter-derived C stored in soils compared to low-quality root litter at the end of the experiment.Root litter quality likely influenced soil C storage via changes in microbial diversity,as the decomposition of high-quality litter declined with increasing bacterial diversity,whereas the amount of litter-derived soil C from low-quality litter increased with fungal diversity.Our results thus reveal that root litter quality mediates decomposition and C storage in subtropical forest soils in China and future work should consider the links between root litter quality and soil microbial diversity.Shan Xu Fanglong Su Emma J.Sayer Shu Kee Lam Xiankai Lu Chengshuai Liu Derrick Y.F.Lai 2023Soil Ecology Letters2023,5,4:0
12Testing potassium limitation on soil microbial activity in a sub-tropical forest显示文摘Because potassium(K)is a rock-derived essential element that can be depleted in highly-weathered tropical soils,K availability may limit some portion of soil microbial activity in tropical forest ecosystems.In this paper we tested if K limits microbial activity in the condition of sufficient labile C supply.An incubation experiment was performed using surface soil samples(0–10 cm depth)obtained from four permanent ecological research plots in a natural sub-tropical forest in southern China.Soil samples were taken in September 2016.Heterotrophic soil respiration rates and microbial biomass were measured after the addition of glucose(both D and L)with and without K(potassium chloride).We did not observe any effects of K addition on soil microbial respiration,suggesting that K does not limit the microbial activity in the condition of sufficient labile C supply.The lack of microbial response to added K can be attributed to the high mobility of K in forest ecosystems,which may have provided sufficient K to microbes in our soil samples(already provided at the beginning of the incubation).However,at the present stage,we cannot conclude that K is not a limiting factor of soil microbial activity in other tropical forest ecosystems because of the heterogeneity of tropical forest ecosystems and few observations.The hypothesis needs to be tested in larger numbers of tropical forests.Taiki Mori Senhao Wang Zhuohang Wang Cong Wang Hui Mo Jiangming Mo Xiankai Lu 2019Journal of Forestry Research2019,30,6:0
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