Page 60 - 《广西植物》2023年第2期
P. 60

2 5 4                                  广  西  植  物                                         43 卷
                 variationꎬ trend analysisꎬ and Hurst indexꎬ based on MOD17A3HGF dataset. Driving factors from natural and human
                 aspects and their influence were also quantitatively explored for vegetation NPP variations using correlation analysis and
                 the Geodetector model. The results were as follows: (1) The temporal variation of vegetation NPP in the Haihe River
                                                                                      ̄1
                 Basin presented a significant growth trend form 2000 to 2020ꎬ with a rate of 1.73 Tg Ca ꎬ and the annual average
                                     ̄2   ̄1
                 NPP was 326.75 g Cm a ꎻ the average NPP of coniferous forestsꎬ broad ̄leaved forestꎬ shrubꎬ grassland and
                                                                 ̄2   ̄1
                 farmland were 313.59ꎬ 385.28ꎬ 353.03ꎬ 320.12ꎬ 295.22 g Cm a . (2) In terms of spatial distributionꎬ the high ̄
                 value areas of vegetation NPP were mainly located in the northwest mountainsꎬ and the low ̄value areas were mainly
                 located in the southeast plainꎻ the overall situation of vegetation NPP was relatively stableꎬ with an average coefficient of
                 variation of 0.17ꎻ the future trend of NPP was anti ̄continuity and might decrease. (3) The correlation analysis showed
                 that vegetation NPP was negatively correlated with temperatureꎬ and positively correlated with precipitation that was the
                 main climate factorꎻ NPP showed an “increase ̄decrease” trend with elevation and slope increasingꎻ the conversion of
                                                                         ̄3
                 farmland to grassland resulted in the largest increment of NPP at 732.22×10 Tg C. (4) From 2000 to 2020ꎬ the average
                 influence value of different drivers was 0.2ꎬ and the order was precipitation > elevation > slope > humidity > temperature >
                 sunshine duration > land use > wind speed. Overallꎬ the results indicated that vegetation NPP in the Haihe River Basin
                 was improving during the study periodꎻ productivity varied among different vegetation typesꎬ with the strongest being
                 broad ̄leaved forest and shrublandꎻ the dominant factors affecting the spatial distribution of vegetation NPP were
                 precipitationꎬ elevation and slopeꎬ and the influence of human factors was lower than that of natural factors. The results
                 of this study provide some scientific reference and decision basis for the treatment of ecological environment such as soil
                 erosion and vegetation degradation in the Haihe River Basin.
                 Key words: net primary productivity(NPP)ꎬ MOD17A3HGFꎬ spatio ̄temporal variationꎬ driving factorsꎬ the Haihe
                 River Basin


                植被净初级生产力( net primary productivityꎬ            学者从不同空间尺度探讨了我国众多区域如秦巴
            NPP)是指绿色植物在单位时间、单位面积内由光                            山区 ( 李 金 珂 等ꎬ 2019)、 西 辽 流 域 ( 朱 丽 亚 等ꎬ
            合作用产生的有机物总量扣除自养呼吸后的剩余                              2020)、南方农牧交错带(赵唯茜等ꎬ2018)、青藏高
            部分( Field et al.ꎬ 1998)ꎮ 植被 NPP 是研究陆地              原( 陈 舒 婷 等ꎬ 2020)、 山 东 省 ( 骆 艳 和 张 松 林ꎬ
            生态系统物质和能量交换的重要指标ꎬ其空间分                              2019)、中国东南部( 崔林丽等ꎬ2016) 等植被 NPP
            布与区域气候、植被生长以及人类活动等因素息                              时空变化及驱动因素ꎬ均发现 NPP 与气温、降水有
            息相关ꎬ该指标的变化能反映植被群落的生产能                              一定的相关性ꎬ但不同地区气象因子对植被 NPP
            力ꎬ是生态系统功能和结构变化的重要表征( 朱文                            的影响力存在明显差异ꎻ当然ꎬ植被 NPP 的时空异
            泉等ꎬ2007)ꎮ 在“ 双碳” 目标的大背景下ꎬ研究植                       质性除了与气象因素有关外ꎬ还受到地形、植被类
            被 NPP 时空变化特征及影响机制对于固碳增汇和                           型等其他自然因素( 朱利欣和袁金国ꎬ2019ꎻ刘婧
            生态修复治理工程等具有重要的意义ꎮ                                  等ꎬ2021) 和 人 为 因 素 ( 袁 甲 等ꎬ2016ꎻ Ge et al.ꎬ
                 植被 NPP 的早期研究主要为站点实测和统计                        2021)的影响ꎮ 因此ꎬ区域尺度植被 NPP 时空异
            模拟ꎬ近年来ꎬ随着新型遥感科学技术与方法的快                             质性的驱动机制尚未完全清晰ꎮ
            速发展ꎬ凭借实时性强、易于获取、覆盖范围广等                                 近年来ꎬ海河流域由于受气候变化、人为干扰
            优点ꎬ利用遥感数据进行模型准确估算已成为区                              等因素影响ꎬ生态系统十分脆弱ꎬ水土流失、植被退

            域 NPP 监测和时空变化趋势分析的强有力手段ꎬ                           化等生态环境问题日益突出(杨艳丽ꎬ2017)ꎮ 植被
            如采用 BIOME ̄BGC 模型(Sun et al.ꎬ 2017)、CASA            NPP 是判定区域生态系统变化及其可持续性的重
            模型(Liu et al.ꎬ 2018) 等ꎮ MOD17A3HGF 是利用             要指标ꎬ而目前关于该区域植被 NPP 的研究较少ꎬ
            BIOME ̄BGC 模型及光能利用率模型模拟得到的                          现有大多数研究多集中于京津冀地区ꎬ且更多从单
            全球生态系统植被 NPP 数据ꎬ该数据集已经在全                           一因素考虑对植被 NPP 的影响ꎮ 因此ꎬ本研究以海
            球不同地区研究中得到应用与验证( Wang et al.ꎬ                      河流域为研究区ꎬ利用 2000—2020 年 MOD17A3HGF
            2021ꎻVenter et al.ꎬ 2021ꎻGe et al.ꎬ 2021)ꎮ 国内      数据集ꎬ结合气温、降水、地形和土地利用等数据ꎬ
   55   56   57   58   59   60   61   62   63   64   65