| 2000~2021年黄土高原生态分区NEP时空变化及其驱动因子 |
| 摘要点击 333 全文点击 53 投稿时间：2023-06-07 修订日期：2023-08-07 |
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| 中文关键词 黄土高原 生态分区 净生态系统生产力 相关分析 残差分析 地理探测器 |
| 英文关键词 Loess Plateau（LP） ecological subregion net ecosystem productivity correlation analysis residual analysis geographic detector |
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| 中文摘要 |
| 净生态系统生产力（NEP）是陆地生态系统碳源/汇定量评价的重要指标.以黄土高原地区及6个生态分区（黄土高塬沟壑区A1、A2副区,黄土丘陵沟壑区B1、B2副区、沙地和农灌区（C区）和土石山区及河谷平原区（D区））为研究对象,结合遥感、气象、地形和人类活动数据,采用相关性分析、多元回归残差分析和地理探测器等方法,估算区域NEP并分析其时空变化特征及气候、地形、人为因子对NEP时空变化的影响.结果表明,在时间尺度上,2000~2021年,黄土高原NEP多年平均值（以C计）为104.62 g·（m2·a）-1.黄土高原及各生态分区NEP均呈增长趋势,其中,黄土高塬沟壑区A2副区NEP年均增长率最大,为9.04 g·（m2·a）-1；沙地和农灌区NEP年均增长率最小,为2.74 g·（m2·a）-1.除沙地和农灌区为弱碳源外,其余各生态分区均表现为碳汇.在空间尺度上,黄土高原年均NEP呈现东南高西北低的分布格局,碳汇高值主要分布在黄土高塬沟壑区南部,碳源区主要分布在黄土高塬沟壑区北部、沙地和农灌区的大部；NEP的空间变化有显著差异,高增幅主要分布在A2副区中南部以及B2副区的西南部.黄土高原及各生态分区NEP时间变化受人为因素影响最大,人类活动数据与NEP的相关系数均大于0.80,且人为因素对NEP的贡献率均在50%以上；NEP的空间变化受气象因子的影响较大,降水、太阳辐射是影响空间变化的主导因子.总之,黄土高原NEP的时空变化受自然因素和人类社会因素共同影响.研究结果可为黄土高原陆地生态系统减排增汇及实现双碳目标提供参考. |
| 英文摘要 |
| Net ecosystem productivity (NEP) is an important index for the quantitative evaluation of carbon sources and sinks in terrestrial ecosystems. Based on MOD17A3 and meteorological data, the vegetation NEP was estimated from 2000 to 2021 in the Loess Plateau (LP) and its six ecological subregions of the LP (loess sorghum gully subregions:A1, A2; loess hilly and gully subregions:B1, B2; sandy land and agricultural irrigation subregion:C; and earth-rock mountain and river valley plain subregion:D). Combined with the terrain, remote sensing, and human activity data, Theil-Sen Median trend analysis, correlation analysis, multiple regression residual analysis, and geographic detector were used, respectively, to explore the spatio-temporal characteristics of NEP and its response mechanism to climate, terrain, and human activity. The results showed that:① On the temporal scale, from 2000 to 2021 the annual mean NEP of the LP region (in terms of C) was 104.62 g·(m2·a)-1. The annual mean NEP for both the whole LP and each of the ecological subregions showed a significant increase trend, and the NEP of the LP increased by 6.10 g·(m2·a)-1 during the study period. The highest growth rate of the NEP was 9.04 g·(m2·a)-1, occurring in the A2 subregion of the loess sorghum gully subregions. The subregion C had the lowest growth rate of 2.74 g·(m2·a)-1. Except for the C subregion, all other ecological subregions (A1, A2, B1, B2, and D) were carbon sinks. ② On the spatial scale, the spatial distribution of annual NEP on the LP was significantly different, with the higher NEP distribution in the southeast of the LP and the lower in the northwest of the LP. The high carbon sink area was mainly distributed in the southern part of the loess sorghum gully subregions, and the carbon source area was mainly distributed in the northern part of the loess sorghum gully subregions and most of the C subregion. The high growth rate was mainly distributed in the central and the southern part of the A2 subregion and the southwest part of the B2 subregion. ③ Human activities had the greatest influence on the temporal variation in NEP in the LP and all the ecological subregions, with the correlation coefficient between human activity data and NEP being above 0.80, and the relative contribution rates of human factors was greater than 50%. The spatial distribution was greatly affected by meteorological factors, among which the precipitation and solar radiation were the main factors affecting the spatial changes in the NEP of the LP. The temporal and spatial variations in the NEP in the LP were influenced by natural and human social factors. To some extent, these results can provide a reference for the terrestrial ecosystem in the LP to reduce emissions and increase sinks and to achieve the goal of double carbon. |
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