植物生态学报 ›› 2019, Vol. 43 ›› Issue (7): 557-565.doi: 10.17521/cjpe.2018.0230

• 研究论文 •    下一篇

降水变化对内蒙古典型草原地上生物量的影响

苗百岭1,2,梁存柱1,*(),史亚博1,梁茂伟1,刘钟龄1   

  1. 1内蒙古大学生态与环境学院, 呼和浩特 010021
    2内蒙古自治区气象科学研究所, 呼和浩特 010051
  • 收稿日期:2018-09-18 接受日期:2019-06-21 出版日期:2019-07-20 发布日期:2019-12-12
  • 通讯作者: 梁存柱 E-mail:bilcz@imu.edu.cn
  • 基金资助:
    国家重点研发计划(2016YFC0500503);内蒙古自治区科技计划(20140409)

Temporal changes in precipitation altered aboveground biomass in a typical steppe in Nei Mongol, China

MIAO Bai-Ling1,2,LIANG Cun-Zhu1,*(),SHI Ya-Bo1,LIANG Mao-Wei1,LIU Zhong-Ling1   

  1. 1School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
    2Inner Mongolia Meteorological Institute, Hohhot 010051, China
  • Received:2018-09-18 Accepted:2019-06-21 Online:2019-07-20 Published:2019-12-12
  • Contact: LIANG Cun-Zhu E-mail:bilcz@imu.edu.cn
  • Supported by:
    Supported by the National Key R&D Program of China(2016YFC0500503);the Science and Technology Project of Nei Mongol Autonomous Region(20140409)

摘要:

降水格局的变化是气候变化影响干旱和半干旱区草原植物群落结构和功能的关键过程。作为植物群落结构和功能的基本组成单位——植物功能群——对气候变化的响应差异明显。有关不同植物功能群如何响应降水格局的研究, 有助于揭示气候变化对干旱与半干旱区生态系统关键功能与过程稳定性的变异机制。该文利用1982-2015年的典型草原群落地上生物量长期动态监测数据及其所对应的气候数据, 系统揭示降水变化对干旱与半干旱区生态系统生产力的影响。主要研究结果如下: 1) 1982-2015年内蒙古典型草原区降水变化特征明显, 主要表现在降水集中度呈显著的降低趋势; 小降水事件(≤5 mm)明显增多。2)降水变化导致群落生物量呈下降趋势。其中, 多年生丛生禾草的生物量呈上升趋势; 一二年生植物、多年生杂类草、多年生根茎禾类草的生物量均呈下降趋势。3)群落生物量与生长季降水量、降水集中度呈显著的正相关关系。各功能群中, 多年生杂类草、半灌木和生长季降水量呈显著正相关关系, 灌木与降水集中度呈显著负相关关系。4)群落生物量与各等级降水的频率相关性均不显著, 但与I-II类(0.1-10 mm)降水贡献率显著负相关。各功能群中, 多年生杂类草与I类降水(0.1-5.0 mm)的发生频率和降水贡献率均呈显著的负相关关系, 与VI类降水(20-25 mm)的发生频率和贡献率均呈显著的正相关关系。多年生根茎禾类草和VIII类降水(>35 mm)的发生频率和贡献率均呈显著的正相关关系。说明小降水事件的增加将显著降低群落的地上生物量, 小降水事件对干旱、半干旱区植被生长具有重要的生态学意义。

关键词: 降水变化, 降水集中度, 典型草原, 地上生物量, 功能群

Abstract:
Aims Precipitation and its spatiotemporal changes are crucial for determining the effects of climate on plant community assembly and functioning of ecosystem (CAFE) in arid and semi-arid regions. Plant functional groups (PFGs) - an effective representation of CAFE—have been widely reported for their identity-dependent response to the changing climate. Here, we examine the responses of different PFGs to the temporal changes in precipitation by using aboveground biomass (AGB) as the dependent variable.
Methods We conducted a long-term ecological research of AGB since 1982 in a typical steppe grassland of Nei Mongol, China. We used the monthly-observation dataset from 1982 through 2015 to quantify the empirical relationships between AGB of different PDFs and precipitation.
Important findings We found that: 1) the decline in precipitation-concentration degree (PCD) was coupled with an increase in small rainfall events (≤5 mm) during the 35-year study period; 2) temporal changes in precipitation resulted in AGB decreases of annuals and biennials (AB), perennial forbs (PF) and perennial rhizome grass (PR), whereas AGB increased for perennial bunchgrasses (PB); 3) AGB, PF and semi-shrubs (SS) were positively correlated with growing season rainfall with AGB positively correlated with PCD while AGB of the shrubs (S) was negatively correlated with PCD; 4) AGB showed no significant correlation with precipitation frequency, but a significant negative correlation for type I to II precipitation 0.1-10 mm; 5) AGB had negative correlations with frequency and amount of type I (0.1-5.0 mm) and type VI (20-25 mm) precipitation. We concluded that the increase in small precipitation events will significantly reduce the AGB. These small precipitation events should be further explored for their ecological significances in the arid and semi-arid regions.

Key words: precipitation dynamics, precipitation-concentration degree, typical steppe, aboveground biomass, plant functional groups