气候变化和人类活动对浙江省植被碳利用率的影响

Influence of climate change and human activities on Vegetation Carbon Use Efficiency in Zhejiang Province

摘要:

植被碳利用率（CUE）是评估植被固碳能力和效率的重要指标，探讨其对气候变化和人类活动的响应对监测区域生态环境质量和研究碳循环具有重要意义。基于MODIS遥感数据，采用Sen斜率估计法和Mann-Kendall显著性检验法研究了2001-2020年浙江省植被CUE的时空变化特征，同时结合地面气象观测站点数据，采用相关性分析和多元回归残差法定量分析气候变化和人类活动对植被CUE的贡献率。结果表明：2001-2020年浙江省植被CUE呈弱下降趋势，平均下降速率为0.0008 a-1（p=0.08）。植被CUE空间分布范围为0.20-0.67，均值为0.50±0.08。植被CUE变化趋势率为-0.017-0.018 a-1，呈增加趋势区域占10.5%，呈降低趋势区域占23.9%。气候变化对植被CUE变化的影响趋势为-0.007-0.010 a-1，植被CUE与气温主要存在显著负相关关系，与降水量主要存在显著正相关关系。人类活动对植被CUE变化的影响趋势为-0.015-0.017 a-1。由气候变化和人类活动双驱动引起植被CUE降低的区域占50.7%，其中，人类活动是主要驱动因素，气候变化为次要驱动因素，气候变化和人类活动对植被CUE变化的相对贡献率分别为33%和67%。综上，近20 a浙江省植被CUE呈弱下降趋势，空间分布差异较大，人类活动对浙江省植被CUE影响更强，主要导致植被CUE降低

Abstract:

Vegetation carbon use efficiency (CUE) is an important indicator to evaluate the carbon sequestration capacity and efficiency of vegetation. It is of great significance to explore its response to climate change and human activities for monitoring regional ecological environment quality and studying carbon cycle. Here, Sen slope estimation and Mann-Kendall significance test were used to analyze the temporal and spatial variation characteristics of vegetation CUE based on MODIS remote sensing data in Zhejiang Province from 2001 to 2020. Furthermore, we conducted correlation analysis and multiple regression residual method based on the data of ground meteorological observation stations to quantify the effects of climate change and human activities on vegetation CUE. The results showed that the vegetation CUE in Zhejiang Province showed a weak downward trend from 2001 to 2020, and the average rate was 0.0008 a-1 (p=0.08). The spatial distribution range of vegetation CUE was 0.20 to 0.67, and the average was 0.50±0.08. The trend rate of vegetation CUE was -0.017-0.018 a-1, and the area showing an increasing trend accounted for 10.5%, and the area showing a decreasing trend accounted for 23.9%. The influence trend of climate change on vegetation CUE change was -0.007-0.010 a-1, vegetation CUE was mainly negatively correlated with temperature and positively correlated with precipitation. The influence of human activities on vegetation CUE change was -0.015-0.017 a-1. The decrease areas caused by climate change and human activities accounted for 50.7%. Among them, human activities were the main driving factors, and climate change was the secondary driving factor. The relative contribution rates of climate change and human activities to vegetation CUE changes were 33% and 67%, respectively. In summary, the vegetation CUE in Zhejiang Province showed a weak downward trend in the past 20 years, and the spatial distribution was quite different. Human activities had a stronger impact on the vegetation CUE in Zhejiang Province, primarily causing them to lower.