【作者】 殷现伟；

【导师】 常杰； 葛滢；

【作者基本信息】 浙江大学 ， 植物学， 2003， 硕士

【摘要】 本文在对野外自然条件下濒危植物明党参（Changium smyrnioides Wolff）和非濒危植物峨参光合碳固定能力测定的基础上，研究了在控制土壤水分条件下明党参、峨参和另外一种濒危植物川明参（Chuanminshen violaceum）的光合和生长特点，比较它们的光合、蒸腾等对光照、温度等环境因子响应及对环境变化适应能力的差异，分析了明党参濒危的原因和机理。研究结果发现， 1．野外自然条件下，明党参光合碳闹定能力远低于峨参。明党参1月萌发，峨参9月萌发，都在6月份进入休眠，明党参的生长时间比峨参短了160天左右。2、3月份均为二者的快速光合期，明党参光合速率分别为9.49和9.3μmol（CO₂）·m^-2·S^-1，分别比峨参高了23％和37％；进入5月份以后光合都下降，明党参仅为1.55μmol（CO₂）·m^-2·S^-1，却比峨参低75％。明党参光合的季节变化远大于峨参：明党参5月份的光合速率较2月份下降了84％，而峨参仅下降了19％。明党参地上生物量比率和叶片数也远低于峨参。明党参的平均单位叶速率和平均相对生长速率分别为0.0313μmol·m^-2·d^-1和0.0215g·g^-1·d^-1，分别仅为峨参34％和64％。因此每个生长季碳积累总量低于峨参，仅为峨参1／3左右。 2．在室内控制水分条件下，明党参光合的理论水分生态位是饱和到中度湿润的土壤条件，川明参的理论水分生态位是中度湿润的土壤，而峨参的理论水分生态位最宽，对饱和到20％水分条件都有较强的适应能力。一年龄和二年龄明党参在饱和和中度湿润条件下的光合显著地比干旱条件下大，并且在胁迫去除后，干旱条件下的明党参恢复能力弱；一年龄川明参在中度条件下光合最大，二年龄川明参在饱和和中度条件下最大，二者没有显著的差异，胁迫去除后恢复能力较明党参强；一年龄峨参饱和和中度水分条件下较干旱高，二年龄峨参则中度条件下最高，干旱条件下光合下降的幅度较小，并且胁迫去除后的恢复能力较强。 3．明党参光合生长能力对土壤水分变化的可塑性大于峨参。明党参在从中度湿润到干旱条件下光合下降的幅度高于峨参，一年龄明党参在于旱比中度湿润条件下光合下降了25％-35％，峨参则下降了15％-25％；二年龄明党参在干旱条件下光合下降了70％-80％，峨参下降了30％左右。 4．明党参和峨参的生长和生殖策略不同。峨参将更多的物质分配到了叶和茎，2、3和4月叶片生物量比率平均为49％，可光合生产更多的物质；而明党参则将相对多的物质分配到了根部，分配到地上部分的物质较少，仅为26％，光合碳固定能力较弱。峨参一次结实，在第2或第3年就进入生殖期，生殖投入较大，平均每株产生1351粒种子，同时通过根部产生无性系的方式进行无性生殖；而明党参一生多次结实，一般在4、5年后才能进入生殖期，生殖投入较小，产生的种子数仅有峨参的1／8左右，没有无性生殖。因此峨参采用快速生长，较短世代周期，快速繁殖快速扩散的r-对策；明党参采用缓慢生长，较长世代间期，多次缓慢生殖的K-对策。 5．明党参地上生物量投入较小，叶片分布较矮，春夏季对光的竞争能力较弱，光合碳固定能力较差，生长较慢，竞争能力较弱。因此在向水分和光照都较好的生境扩散时，没有 取得成功，而仅占据了落n一卜林下和林缘路边的生境。但在这种生境中，仅能利用春季的 时间进行生长，生长时间较短，碳积累能力有限，在加上其生殖能力较弱，因此其种群 扩展能力弱，并且在遭到破坏后，恢复很慢。峨参地上生物量投入较大，叶片对光的竞 争能力较强，光合碳固定较强，竞争能力较大。因此占据了光照和水分都较好的生境， 生长时间较长，碳积累能力强，生殖投入较大，因此种群扩展能力较强，并且在遭到破 坏后，能较快恢复。6.明党参自身的生物学特性决定了其在没有人为干扰或干扰较小的情况下可以形成一个较 为稳定的种群，但生境遭到破坏后，种群扩展和恢复能力有限，甚至不能恢复。其濒危 是自身特性和人为影响综合作用的结果。更多还原

【Abstract】 Based on the research of photosynthetic carbon assimilation in natural habitat, the physiecological features of net photosynthesis (PN) and growth of Changium smyrnioides Wolff and Anthriscus sylvestri (L.) Hoffm were measured under controlled soil water status (saturation status (SS), moderate status (AW50) and dry status (AW20)), the difference of photosynthesis and transpiration to environmental factors and the adaptation to environmental fluctuation compared, to analyze the mechanism of C. smyrnioides to be endangered. Results showed that:1. The photosynthetic carbon assimilation ability of C. smyrnioides was lower than that of A. sylvestris under natural environment. C. smyrnioides germinates in December and A. sylvestri in September, begin dormancy in June and bear fleshy storage roots. The growing season of C. smyrnioides is therefore 160 days shorter than that of. A. sylvestri. They all grew rapidly in February and March, the PN of C. smyrnioides were 9.49 u mol(CO2)m-2 s-1 and 9.36 u mol(CO2) m-2 s-1 respectively, which were 23% and 37% higher than those of A. sylvestri. In the following May, the growth and photosynthesis of them slowered, the PN of C. smyrnioides declined to 1.55 u mol(CO2) m-2 s-1, 75% lower than that of A. sylvestri. The seasonal fluctuation of PN of C. smyrnioides was larger than that of A. sylvestri: the PN of C. smyrnioides was 84% lower in May that of in February, while A. sylvestri was only 19%. The leaf number and aboveground biomass ratio of C. smyrnioides were far less than those of A. sylvestri.2. Under controlled soil water status, the theoretical water niche of C. smyrnioides was saturate and moderate soil water status; Chuanminshen violaceion was moderate, while A. sylvestri was the most broad, and adapted well from saturation to 20% water sattus. The photosynthesis of one-year-old and two-year-old C. smyrnioides was higher in saturate and moderate than that of in dry, the recovery of photosynthesis in dry condition was weak when they watered to saturation. The photosynthesis of one-year-old C. violaceum was higher in moderate than in two others; two-year-old was higher in saturate and moderate than in dry, the former two had little difference. The recovery of C. violaceum was better than that of C. smyrnioides. The photosynthesis of one-year-old A. sylvestri was higher in saturate and moderate than in dry; two-year-old was higher in moderate than in saturate and dry. The declining extent of photosynthesis in dry water status was small, and the recovery was better than two other species.3. C. smyrnioides displayed larger plasticity of photosynthesis and growth than A. sylvestri to soil water status changes: the decline extant of C. smyrnioides in dry water status is higher than those of A. sylvestri. The photosynthesis of one-year-old C. smyrnioides decreased 25-35% in dry water status, A. sylvestri decreased 15-25%; the two-year-old decreased 70-80% and about 30% respectively.4. C. smyrnioides and A. sylvestri took different growth and reproduction strategy. A. sylvestri allocated more resource to leaf and stem, the average ratio of leaf biomass in February, March and April was 49%, which could fix more matter via photosynthesis. C. smyrnioides allocatedmore resource to root, so the resource to aboveground was relatively small, the ratio was only 26%, and the carbon assimilation via photosynthesis was weak. A. sylvestri is monocarpic, and begin to procreate in the second or third year. The reproductive allocation of A. sylvestri was large and produced 1351 seed every individual, it also had asexual reproduction by producing remets from root. C. smyrnioides is polycarpic and takes four to five or more years to procreate. The reproductive allocation of C. smyrnioides small and bore less seeds only one eighth of A. sylvestri, it didn’t has asexual reproduction. Accordingly, A. sylvestri took the r-strategy to occupy niche, which growing fast and having shorter heterogamous interval, breeding and spreading quickly. While C. smyrnioides took K-strat更多还原