【作者】 刘晓强；

【导师】 王仁忠；

【作者基本信息】 中国科学院研究生院（植物研究所） ， 生态学， 2006， 博士

【摘要】 植物功能型的研究是全球变化研究当中最重要的创新之一,作为新的研究手段,已经被广泛用来研究全球变化的影响。而关于不同植物功能型对全球变化的生理生态反应、植物功能型对全球变化的适应机制及植物功能型演变在全球变化中的作用等方面的研究报道却很少,相关方面的研究尚处于起步阶段,而这些恰恰是植物功能型研究的基本点和最终目的,尤其对于全球变化预测模型的研究具有深远的意义。因此深入开展区域环境或全球变化下植物功能型的变化和适应机制研究能为最大程度地获得全球变化对未来影响提供重要信息。本研究中我们对京北农牧交错区的植物功能型(光合功能型和形态功能型)进行了研究。利用稳定性同位素判定法对锡林郭勒草原四种不同草地类型植物功能型进行了分析研究,在调查的125种维管植物中有4种C4植物,其中禾本科和藜科各有2种,C4植物约占该地区调查植物总数的3%,C3植物为94%、CAM植物为3%。研究中发现利用稳定性同位素技术判定CAM类型存在一定的局限性,需要采用辅助实验进行补充。研究结果还表明自东向西,在草甸草原-典型草原-荒漠草原这一系列草原类型中随着降雨量的逐渐降低,植物种类组成逐渐降低,但C4/C3的比例却有升高的趋势,说明植物光合类型的组成与水分梯度相关。在相同的环境梯度下,多年生高禾草和多年生杂类草呈现显著减少的趋势;而一年生杂类草,多年生矮禾草、灌木和鳞茎类植物呈现显著增加的趋势。这些结果为我们预测该地区植物功能型对全球变化影响的响应提供了依据。在北京北部农牧交错区对不同生境类型的植物功能型进行了研究,该区域有C4植物68种。具有C4植物的科相对集中,主要分布在禾本科(29属43种)、莎草科(4属16种)和藜科(3属5种)。菊科、豆科和蔷薇科这3大科中没有发现C4植物。C4植物约占该地区调查植物总数的9%,C3植物为89%、CAM植物为2%。多年生高禾草和多年生杂类草的比例无论从生长条件良好的草地到沙地,还是从草地到弃耕干扰地都呈现显著下降的趋势,而一年生杂类草和一年生禾草的变化却呈相反的变化趋势。C4植物中一年生植物占的比例最大,而且各个生境中C4植物在一年生植物的比例均超过30%,这说明该地区各个生境植被都已有更多还原

【Abstract】 The study of plant functional types, which has been hailed as one of the most important innovations in studying global change, has been widely adopted to investigate the effects of global change. However, in such areas as the physiological and ecological responses of plant functional types to global changes, the adaptive mechanisms of different plant functional types to global changes as well as the function of the evolution of plant functional types in the global changes, few reports have been seen. The related research is still in the initial stage, however, they are the starting point and ultimate purpose of the study of plant functional types, and in particular, they have a far-reaching significance in forecasting global change patterns. Therefore, by conducting research on the transformations and adaptive mechanisms of plant functional types in the regional or global environmental change, we may obtain a wealth of important information of the impacts of future global changes.In this study, we carried out a study of plant functional types on North-Beijing agro-pastoral ecotone. By stable isotope measurements, we analyzed four plant functional types in Xilingol steppe and got the following results. Carbon isotope ratios indicative of C4 photosynthesis were found in 4 species of the 125 vascular plants investigated, 2 were found in Graminea and the other two in Chenopodiaceae. As for the proportion of photosynthesis pathway, C4 species makes up 3% of the total species investigated in the region, C3 Species 94% and CAM 3%. Six species have C3 photosynthesis, reported previously with C4 photosynthesis. In identifying CAM plants,δ13C method has its own limitation. Therefore, additional experiments are required. In the series of meadow types更多还原