Seasonal change mediates the shift between resource and pollen limitation in Hedysarum scoparium(Fabaceae)  

作　　者：ChengChen Pan Qi Feng HaLin Zhao XueYong Zhao LinDe Liu JiLiang Liu Li Zhang Jin Li 

机构地区：[1]Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences [2]School of Life Sciences,Ludong University

出　　处：《Research in Cold and Arid Regions》2015年第1期94-98,共5页寒旱区科学（英文版）

基　　金：funded by the National Natural Science Foundation of China (31400392,91025002,31370466);the Foundation for Excellent Youth Scholars of CAREERI,CAS (Y451111001);a General Financial Grant from the China Postdoctoral Science Foundation (2014M552516)

摘　　要：Theory suggests that with sufficient environmental variation, pollen limitation might be observed at some places or times, and resource limitation at others, but there are no empirical data about the effect of seasonal change on the variation of pollen limitation and resource limitation within a flowering season. In this study, we examined pollen and resource limi- tation by comparing fruit set and seed production in natural- and hand-pollinated Hedysarum scoparium flowers in the middle reaches of the Hexi Corridor region, China, in 2010. We also described a role for the first substantial autumn rainfall in mediating a shift between pollen and resource limitation in H. scoparium, but did not analyze this experimentally Our results indicated that H. scoparium was resource limited at peak flowering during the summer, and was pollen limited at peak flowering during the autumn. The seasonal change （summer to autumn） mediated the shift between pollen and resource limitations in H. scoparium. The shift timing depended on the date of the first autumn rainfall in 2010. Changes in the first substantial rainfall in autumn may affect fruiting of H. scoparium, thus affecting population persistence of this species and development/structure of the local ecosystem if such conditions persist.Theory suggests that with sufficient environmental variation, pollen limitation might be observed at some places or times, and resource limitation at others, but there are no empirical data about the effect of seasonal change on the variation of pollen limitation and resource limitation within a flowering season. In this study, we examined pollen and resource limi- tation by comparing fruit set and seed production in natural- and hand-pollinated Hedysarum scoparium flowers in the middle reaches of the Hexi Corridor region, China, in 2010. We also described a role for the first substantial autumn rainfall in mediating a shift between pollen and resource limitation in H. scoparium, but did not analyze this experimentally Our results indicated that H. scoparium was resource limited at peak flowering during the summer, and was pollen limited at peak flowering during the autumn. The seasonal change （summer to autumn） mediated the shift between pollen and resource limitations in H. scoparium. The shift timing depended on the date of the first autumn rainfall in 2010. Changes in the first substantial rainfall in autumn may affect fruiting of H. scoparium, thus affecting population persistence of this species and development/structure of the local ecosystem if such conditions persist.

关 键 词：plant reproductive ecology fruit set seed production Hedysarum scoparium 

分 类 号：Q948[生物学—植物学]