模拟干旱对藏北高寒草甸植物物候期和生产力的影响

为探究生长季不同时期干旱事件对高寒草甸植物物候期和生产力的影响,采用截雨棚于藏北高寒草甸生长季前期和后期进行为期2年(2016-2017年)的截雨试验.结果表明:1)植物物候期对不同时期干旱处理响应不同,高寒草甸关键物种植物物候期对生长季前期干旱(SE)响应较为敏感,SE会导致植物返青期大幅推迟,生长季长度和繁殖期明显...

Effects of simulated drought on plant phenology and productivity in an alpine meadow in Northern Tibet

This research aimed to elucidate the effects of drought events on the phenology and productivity of the plant community in Tibetan alpine meadow.A rainfall interception experiment comprising drought treatments imposed early or late in the growing season(SE and SL,respectively)was carried out in alpine meadow of Northern Tibet,over two years(2016-2017).Results showed that:1)The plant phenology had a contrasting response to SE and SL drought treatments.Plant phenology of key species was more sensitive to SE.SE significantly delayed plant green update,and led to a shorter growing season and reproductive duration(P<0.05),while SL had no significant effect on plant phenology.2)Biomass of the plant community and different functional groups decreased under the drought treatments.Community biomass decreased by 62.9%(P<0.05).The height and coverage of the community was suppressed by drought,while the response of height and coverage differed between grasses and forbs.3)Community height and biomass were significantly positively correlated with the growing season and reproductive duration(P<0.05).The results indicate that the productivity of alpine meadow grassland was regulated by phenology in response to drought,mainly through the impact on plant height.Moreover,the responses to drought varied between different functional groups,and suggest that increasing and intensified drought may lead to change in the community structure of alpine meadow.