Guangzhou Institute of Geography, Guangdong Open Laboratory of Geospatial Information Technology and Application, Guangzhou 510070, China; Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation, School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China.
Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation, School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China; Xinhua College of Sun Yat-sen University, Guangzhou 510520, China.
Sci Total Environ. 2018 Sep 1;635:26-34. doi: 10.1016/j.scitotenv.2018.04.057. Epub 2018 Apr 13.
Land urbanization can affect carbon sequestration. In this study, the relationships between land urbanization and carbon sequestration of urban vegetation were studied for Guangzhou, China. The methodology was based on land use data from Thematic Mapper (TM) imagery, MODIS13Q1 data, and climate data, and the improved Carnegie-Ames-Stanford approach (CASA) model and linear system models were employed. Characteristics such as the amount of expansion, spatial agglomeration, spatial expansion intensity, and spatial growth of built-up land were analyzed, and the influence of land urbanization (built-up land expansion) on carbon sequestration of urban vegetation was elucidated by a temporal sequential cooperativity analysis. The main results were as follows. (1) Land urbanization had a clear influence on carbon sequestration of urban vegetation in Guangzhou, and the proportion and spatial agglomeration of built-up land showed significant negative correlations with this carbon sequestration; the correlation coefficients were -0.443 and -0.537, respectively, in 2014. (2) The spatial expansion intensity and spatial growth of built-up land showed small correlations with carbon sequestration, and the correlations from 2000 to 2005 were relatively larger than those at other times; this was because the built-up land expansion speed was the fastest during this period. (3) The temporal sequential cooperativity analysis revealed that carbon was lost as natural surfaces were transformed to artificial surfaces, and land urbanization effects on carbon sequestration showed no significant temporal lag. Carbon sequestration of urban vegetation in the city could be improved by adding urban green spaces; however, this would likely take some time as the system recovers.
土地城市化会影响碳固存。本研究以中国广州市为例，探讨了土地城市化与城市植被碳固存的关系。研究方法基于 TM 影像、MODIS13Q1 数据和气候数据的土地利用数据，采用改进的 Carnegie-Ames-Stanford 模型（CASA）和线性系统模型。分析了扩展量、空间集聚、空间扩展强度和城市建设用地空间增长等特征，并通过时间序列协同分析阐述了土地城市化（城市建设用地扩展）对城市植被碳固存的影响。主要结果如下：（1）土地城市化对广州市城市植被碳固存有明显影响，城市建设用地的比例和空间集聚与碳固存呈显著负相关，相关系数分别为-0.443 和-0.537，均在 2014 年；（2）城市建设用地的空间扩展强度和空间增长与碳固存呈较小的相关性，2000-2005 年的相关性大于其他时期，因为这一时期城市建设用地扩展速度最快；（3）时间序列协同分析表明，自然表面向人工表面转化会导致碳损失，土地城市化对碳固存的影响没有明显的时间滞后。通过增加城市绿地可以提高城市植被的碳固存，但这需要一定的时间让系统恢复。
