Theme 5: Drought--Oral Sessions

Description

More extreme precipitation patterns are occurring worldwide in the context of global climate change. These patterns are characterized by larger event size separated by longer within-season drought periods, which are novel climatic conditions to many ecosystems while their consequences are largely unknown. Consequences of changed precipitation patterns on grassland could be complex since the effects of precipitation interval and total precipitation quantity can interact greatly with each other, and can differ among co-existing dominant species. Meanwhile, few researches explored the impacts of changed precipitation patterns on the hidden half – grassland root system. The objective of this study is to explore the responses of co-existing dominant species (Leymus chinensis and Stipa grandis) of Inner Mongolia typical grassland to changed precipitation pattern. A simulated experiment over the whole growing season (July to September) was conducted in open-top chambers at Inner Mongolia Grassland Ecosystem Research Station of Chinese Academy of Sciences. The research examined the effects of total precipitation quantity and precipitation interval on their aboveground and belowground growth and root/shoot ratio. It was found that precipitation interval was as significant as total precipitation quantity in affecting growth of the two dominant species. Belowground growth of Leymus chinensis and Stipa grandis responded to changed precipitation patterns in opposite ways, and the effects of total precipitation quantity and precipitation interval depended greatly on each other. It was inferred that precipitation pattern of relatively higher total precipitation quantity and relatively longer precipitation interval would favour growth of Leymus chinensis, and precipitation pattern of relatively lower total precipitation quantity and relatively longer precipitation interval would favour for growth of Stipa grandis. These differential results provide important insight for drought management strategies in this area in face of future climate change scenarios.

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Differential Effects of Changed Precipitation Patterns on Co-Existing Dominant Species in Inner Mongolia Typical Grassland: Significance for Drought Management

More extreme precipitation patterns are occurring worldwide in the context of global climate change. These patterns are characterized by larger event size separated by longer within-season drought periods, which are novel climatic conditions to many ecosystems while their consequences are largely unknown. Consequences of changed precipitation patterns on grassland could be complex since the effects of precipitation interval and total precipitation quantity can interact greatly with each other, and can differ among co-existing dominant species. Meanwhile, few researches explored the impacts of changed precipitation patterns on the hidden half – grassland root system. The objective of this study is to explore the responses of co-existing dominant species (Leymus chinensis and Stipa grandis) of Inner Mongolia typical grassland to changed precipitation pattern. A simulated experiment over the whole growing season (July to September) was conducted in open-top chambers at Inner Mongolia Grassland Ecosystem Research Station of Chinese Academy of Sciences. The research examined the effects of total precipitation quantity and precipitation interval on their aboveground and belowground growth and root/shoot ratio. It was found that precipitation interval was as significant as total precipitation quantity in affecting growth of the two dominant species. Belowground growth of Leymus chinensis and Stipa grandis responded to changed precipitation patterns in opposite ways, and the effects of total precipitation quantity and precipitation interval depended greatly on each other. It was inferred that precipitation pattern of relatively higher total precipitation quantity and relatively longer precipitation interval would favour growth of Leymus chinensis, and precipitation pattern of relatively lower total precipitation quantity and relatively longer precipitation interval would favour for growth of Stipa grandis. These differential results provide important insight for drought management strategies in this area in face of future climate change scenarios.