CAJ | 학술논문

用稳定性同位素技术,研究了锡林河流域不同群落和生境下羊草(Leymus chinensis ( Trin.) Tzvel.)和糙隐子草(Cleistogenes squarrosa (Trin.) Keng.)叶片δ13C值及其水分利用效率的变化.结果表明,在不同生境下,羊草和糙隐子草叶片δ13C 值随土壤水分含量的降低而增大,并与不同土层土壤水分含量均表现出极显著的线性负相关关系;而二者的叶片水分含量与土壤水分含量无显著的相关关系.这一结果说明,羊草和糙隐子草的水分利用效率均随土壤水分含量的降低而提高,而叶片水分含量保持相对稳定.这两种植物可能通过调节气孔导度、提高水分利用效率和增强渗透调节能力等生理生态机制适应水分状况不同的生境,从而使它们能够在锡林河流域不同植物群落中广泛分布并成为建群种或优势种.
용은정성동위소기술,연구료석림하류역불동군락화생경하양초(Leymus chinensis ( Trin.) Tzvel.)화조은자초(Cleistogenes squarrosa (Trin.) Keng.)협편δ13C치급기수분이용효솔적변화.결과표명,재불동생경하,양초화조은자초협편δ13C 치수토양수분함량적강저이증대,병여불동토층토양수분함량균표현출겁현저적선성부상관관계;이이자적협편수분함량여토양수분함량무현저적상관관계.저일결과설명,양초화조은자초적수분이용효솔균수토양수분함량적강저이제고,이협편수분함량보지상대은정.저량충식물가능통과조절기공도도、제고수분이용효솔화증강삼투조절능력등생리생태궤제괄응수분상황불동적생경,종이사타문능구재석림하류역불동식물군락중엄범분포병성위건군충혹우세충.
Water is usually considered to be a key limiting factor for the growth and reproduction of steppe plants in the Xilin River Basin, Nei Mongol. Foliar δ13C values, an indicator of long_term intercellular carbon dioxide concentration and thus of water_use efficiency (WUE) in plants, were measured on Leymus chinensis (Trin.) Tzvel. and Cleistogenes squarrosa (Trin.) Keng. in six communities of different habitats in the Xilin River Basin. The foliar δ13C values of both species tended to increase with decreasing soil water content (SWC) and a significant negative correlation was found between foliar δ13C values and SWC in different soil layers, indicating that the two species could change WUE according to water availability. We also found relatively constant leaf water contents (LWC) of the two species in different habitats. Our results implied that the two steppe species might have adapted to different soil water regimes either through adjusting stomatal conductance to get a proper WUE, or through enhancing the osmosis_regulating ability to keep a relatively stable LWC. Our findings could partially explain why the two plant species have a wide distribution range and become dominant in the Xilin River Basin.