Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil wate...Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil water supply, ramet pairs of the species were subjected to heterogeneous water supply by which either mother ramets or daughter ramets were in high or low soil water supply, respectively, in the Maowusu (Mu Us) Sandy Land of Nei Mongol. The results showed that the phenotypic characteristics of the individual ramets of C epigejos were greatly influenced by the heterogeneous water supply. The ramets treated with high water supply significantly produced more new rhizomes and more offspring (ramets), and accumulated more shoot biomass, and allocated more biomass to their shoots than those treated with low water supply. In comparison with the daughter ramets in homogeneous soil water supply, phenotypic characteristics, in terms of new rhizome growth, the production of new offspring, and the biomass allocation pattern, of the daughter ramets within the pairs of the species were not significantly changed, no matter that high or low soil water supply to mother ramets. The phenotypic responses of mother ramets to soil water supply were similar to those of daughter ramets. From these results, it is inferred that the interconnected ramets of C epigejos response phenotypically to their local soil water rather than to the soil water experienced by the interconnected ramets. The interconnected ramets of C epigejos might be independent of each other in water relationship, although they are physically interconnected with rhizome segments. The physiological independence of interconnected ramets might facilitate the risk spreading and thus enhance the genet survivorship under the frequent drought stresses in Mu Us Sandland.展开更多
根据野外考察、结合遥感影像、相关的全新世湖相地层及其年代和历史文献等对毛乌素沙漠南缘的城川古湖范围、消亡时间和原因进行了综合分析。研究表明:①城川古湖实际面积比原来认为的100 km^(2)的分布更广,达130 km^(2)左右;②古湖消...根据野外考察、结合遥感影像、相关的全新世湖相地层及其年代和历史文献等对毛乌素沙漠南缘的城川古湖范围、消亡时间和原因进行了综合分析。研究表明:①城川古湖实际面积比原来认为的100 km^(2)的分布更广,达130 km^(2)左右;②古湖消亡时间约在300 a AD(公元300年)且古湖的盛衰与我国和北半球气温的升降趋势吻合;③300 a AD以后我国和北半球气温虽然几度升高,但古湖不再复兴,其原因与自那时以来古湖东缘最低洼区域的新构造运动由沉降转为抬升并孕生出的萨拉乌苏河谷有关。不仅如此,在300 a AD以来新构造抬升的背景下,人类活动对不透水层——全新世湖积物的改造和破坏导致的“人工排水系统”也加速了原来古湖范围地表水体的流失、相继贯入萨拉乌苏河和无定河并最终成为连接黄河的“东逝之水”。展开更多
[Objective] The research aimed to study the groundwater environment related to vegetation in Mu Us Desert.[Method] Choosing the hinterland of Mu Us Desert,the relationship between vegetation and groundwater in the des...[Objective] The research aimed to study the groundwater environment related to vegetation in Mu Us Desert.[Method] Choosing the hinterland of Mu Us Desert,the relationship between vegetation and groundwater in the desert was studied.The indicator system for the relationship between vegetation and groundwater in the sandy area was established,including vegetation population,vegetation cover,groundwater depth,vadose zone moisture content,groundwater mineralization and vadose zone salinity,as well as the corresponding field work methods.[Result] The result showed that the nine primary vegetation populations were distributed in the study area,and Artemisia,Salix and Cares were the dominant vegetation species.The groundwater mineralization in the sand dunes was 100-300mg/L,and 800mg/L in the beach,vadose zone moisture content remained at 8%-16%.The dunes salinity was less than 0.2%,and beaches were higher than 0.3%.[Conclusion] These results provided a basis for study on the relationship between vegetation and groundwater in Mu Us Desert.展开更多
文摘Calamagrostis epigejos (L.) Roth. is a perennial grass with slender and long rhizome segments between interconnected neighbor ramets. To investigate the phenotypic plasticity in response to the heterogeneous soil water supply, ramet pairs of the species were subjected to heterogeneous water supply by which either mother ramets or daughter ramets were in high or low soil water supply, respectively, in the Maowusu (Mu Us) Sandy Land of Nei Mongol. The results showed that the phenotypic characteristics of the individual ramets of C epigejos were greatly influenced by the heterogeneous water supply. The ramets treated with high water supply significantly produced more new rhizomes and more offspring (ramets), and accumulated more shoot biomass, and allocated more biomass to their shoots than those treated with low water supply. In comparison with the daughter ramets in homogeneous soil water supply, phenotypic characteristics, in terms of new rhizome growth, the production of new offspring, and the biomass allocation pattern, of the daughter ramets within the pairs of the species were not significantly changed, no matter that high or low soil water supply to mother ramets. The phenotypic responses of mother ramets to soil water supply were similar to those of daughter ramets. From these results, it is inferred that the interconnected ramets of C epigejos response phenotypically to their local soil water rather than to the soil water experienced by the interconnected ramets. The interconnected ramets of C epigejos might be independent of each other in water relationship, although they are physically interconnected with rhizome segments. The physiological independence of interconnected ramets might facilitate the risk spreading and thus enhance the genet survivorship under the frequent drought stresses in Mu Us Sandland.
文摘根据野外考察、结合遥感影像、相关的全新世湖相地层及其年代和历史文献等对毛乌素沙漠南缘的城川古湖范围、消亡时间和原因进行了综合分析。研究表明:①城川古湖实际面积比原来认为的100 km^(2)的分布更广,达130 km^(2)左右;②古湖消亡时间约在300 a AD(公元300年)且古湖的盛衰与我国和北半球气温的升降趋势吻合;③300 a AD以后我国和北半球气温虽然几度升高,但古湖不再复兴,其原因与自那时以来古湖东缘最低洼区域的新构造运动由沉降转为抬升并孕生出的萨拉乌苏河谷有关。不仅如此,在300 a AD以来新构造抬升的背景下,人类活动对不透水层——全新世湖积物的改造和破坏导致的“人工排水系统”也加速了原来古湖范围地表水体的流失、相继贯入萨拉乌苏河和无定河并最终成为连接黄河的“东逝之水”。
基金Supported by The Key Grant Project of Chinese Ministry of Education(308021)Program for Changjiang Scholars and Innovative Research Team in University (IRT0811)Geological Survey Project of China Geological Survey (1212010331302)
文摘[Objective] The research aimed to study the groundwater environment related to vegetation in Mu Us Desert.[Method] Choosing the hinterland of Mu Us Desert,the relationship between vegetation and groundwater in the desert was studied.The indicator system for the relationship between vegetation and groundwater in the sandy area was established,including vegetation population,vegetation cover,groundwater depth,vadose zone moisture content,groundwater mineralization and vadose zone salinity,as well as the corresponding field work methods.[Result] The result showed that the nine primary vegetation populations were distributed in the study area,and Artemisia,Salix and Cares were the dominant vegetation species.The groundwater mineralization in the sand dunes was 100-300mg/L,and 800mg/L in the beach,vadose zone moisture content remained at 8%-16%.The dunes salinity was less than 0.2%,and beaches were higher than 0.3%.[Conclusion] These results provided a basis for study on the relationship between vegetation and groundwater in Mu Us Desert.
