植物生态学报 ›› 2024, Vol. 48 ›› Issue (10): 1256-1273.DOI: 10.17521/cjpe.2023.0076  cstr: 32100.14.cjpe.2023.0076

• 研究论文 • 上一篇    下一篇

海河流域生态系统净初级生产力对气象干旱的响应与弹性

黄砺成1,2, 莫兴国1,2,3,*()   

  1. 1中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室, 北京 100101
    2中国科学院大学资源与环境学院, 北京 100049
    3中国科学院大学中丹学院, 北京 100049
  • 收稿日期:2023-03-16 接受日期:2024-01-16 出版日期:2024-10-20 发布日期:2024-12-03
  • 通讯作者: 莫兴国
  • 基金资助:
    国家重点研发计划(2022YFF0801804)

Response and resilience of net primary productivity of the Hai River Basin ecosystems under meteorological droughts

HUANG Li-Cheng1,2, MO Xing-Guo1,2,3,*()   

  1. 1Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    2College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    3Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2023-03-16 Accepted:2024-01-16 Online:2024-10-20 Published:2024-12-03
  • Contact: MO Xing-Guo
  • Supported by:
    National Key R&D Programme of China(2022YFF0801804)

摘要: 干旱强度和频率上升严重威胁陆地生态系统结构和功能。为保证未来逆境下生态系统服务功能的正常发挥, 生态系统生产力对气象干旱响应与弹性的时空特征亟待探究。本研究以海河流域2001-2018年标准化降水蒸散指数(SPEI)度量气象干旱, 基于流域自然植被净初级生产力(NPP), 分析NPP与SPEI的数量关系, 评估自然植被的干旱风险及植被在干旱后呈现的弹性。结果显示: (1)海河流域自然植被NPP和归一化植被指数(NDVI)在研究期内均呈显著上升趋势; (2)植被NPP对干旱响应的滞后时间呈草原、稀树草原<落叶阔叶林、多树草原<落叶-常绿混交林、郁闭灌丛; (3)干旱致灾风险则呈现草原>郁闭灌丛>多树草原>落叶阔叶林>稀树草原>落叶-常绿混交林; (4)干旱后流域75%以上植被NPP明显偏低不超过1个月, 弹性较强; 森林类植被的弹性强于灌草类, 二者年内变化趋势相反, 年际均呈增长趋势; NPP响应和弹性特征随植被类型和干旱强度而变。基于植被干旱风险和弹性调整造林还草措施, 优化植被结构, 提升物种多样性, 可提高流域生态系统的稳定性。

关键词: 气象干旱, 干旱风险, 弹性, 净初级生产力, 标准化降水蒸散指数(SPEI)

Abstract:

Aims The increases in drought intensity and frequency severely threaten structure and functioning of terrestrial ecosystems. To ensure the normal functioning of ecosystems under such scenarios, it is critically needed to understand the spatial-temporal characteristics of ecosystem productivity response and resilience under meteorological droughts.

Methods The intensity and frequency of meteorological droughts were quantified by standardized precipitation evapotranspiration index (SPEI) of the Hai River Basin (HRB). Net primary productivity (NPP) of natural ecosystems was estimated based on Carnegie-Ames-Stanford Approach (CASA). We quantitatively analyzed the relationship between NPP and SPEI, evaluated the drought risk of natural vegetation and the resilience of vegetation after drought.

Important findings (1) Both NPP and normalized differential vegetation index (NDVI) in the HRB showed significantly increasing trend. (2) The lagging time of NPP response to droughts follow an order of grassland and savanna < deciduous broadleaf forest and woody savanna < deciduous-evergreen mixed forest and closed shrubland. (3) Drought risk followed an order of grassland > closed shrubland > woody savanna > deciduous broadleaf forest > savanna > deciduous-evergreen mixed forest. (4) More than 75% of the vegetation in the HRB showed no continuous distinctly low NPP status one month after the droughts, indicating relatively strong resilience. The resilience of forests was stronger than shrub or herbaceous vegetation, which showed opposite temporal pattern within each growing season but shared similar increasing trend interannually. Response and resilience characteristics of NPP varied with vegetation types and drought intensity. Ecosystem stability of the HRB could be improved by adjusting the afforestation and grass restoration measures based on vegetation drought risk and resilience, optimizing vegetation structure, and enhancing species diversity.

Key words: meteorological drought, drought risk, resilience, net primary productivity, standardized precipitation evapotranspiration index (SPEI)