【作者】 游文华；

【导师】 于丹；

【作者基本信息】 武汉大学 ， 生态学， 2013， 博士

【摘要】 本文通过模拟和受控实验,研究了水生植物乡土种和外来种对升温和营养添加等条件下的生理生态适应。实验结果如下：1.通过温室模拟实验探讨了冬季对入侵种凤眼莲越冬成活率、繁殖和入侵性的影响,升温显著增加了凤眼莲越冬成活率；凤眼莲越冬后将更多的生物量物分配到冠层以支持其快速繁殖和扩散。凤眼莲短缩茎的大小和埋深也影响其越冬成活率和生长。结合水体营养添加探讨了凤眼莲的生物量分配和碳氮平衡的影响。温度和水体营养升高显著促进了凤眼莲的生长和克隆繁殖,并使其分配更多的生物量到地上部分以支持其快速生长和克隆繁殖；叶片和茎的N含量增加,以促进凤眼莲的光合作用和营养物质储藏。而低的C/N比加快了营养物质周转,使凤眼莲可利用的营养增多。2.比较了升温、淹水和基质营养增加对入去侵种喜旱莲子草和乡土种水龙的影响,喜旱莲子草生长、繁殖和和生物量分配能更好的响应资源的波动,形成竞争优势并有利于其入侵性。研究了沉水植物菹草光合生理与碳氮平衡对升温和水体DIC浓度升高的响应。升温和DIC浓度上升对菹草的影响为拮抗效应。春季升温降低菹草叶片光合作用速率与生物量积累,而DIC浓度的上升则显著提高了菹草叶片光合效率。结合无机N添加探讨了水鳖科三种植物的生理生态响应,水体无机N添加显著增加了轮叶黑藻的生物量；水体中C源的增加有利于外来种埃格草的生长,升温则显著降低了外来种伊乐藻的生物量积累。无机N添加增加了三种植物体内的N含量和游离氨基酸含量。3.通过对与母株相连或切断的分株施加不同降水量或者降水频率,研究了水分时空异质条件下克隆整合对外来种聚叶狐尾藻的影响。克隆整合显著增强了聚叶狐尾藻的生长和光合能力；其分株能通过克隆整合改变分配到根的生物量来提高获取水资源的效率,缓解分株在缺水条件下光化学最大量子产量的下降,并能帮助分株维持相对稳定的N浓度和C/N比率以帮助其健康生长。研究了开顶气室(OTCs)升温对水陆交错区挺水植物群落的影响。挺水植物对升温的响应具有种的特异性；升温使荆三棱等大中型植物比例增加,植株个体变大,并降低了群落内物种多样性；升温使小型植物消失速率加快。更多还原

【Abstract】 In this paper, simulated and controlled experiments were employed to study the physiological and ecological adaptation of native and exotic aquatic plants in response to warming, nutrition addition and other factors under global warming, the results are as follows:1. Simulated warming experiments in the greenhouse were conducted to investigate the effects of winter warming on overwintering survival rate, clonal propagation and invasiveness of invasive species Eichhornia crassipes. Overwintering survival rate of E. crassipes was significantly improved by winter warming. More biomass of E. crassipes was allocated to shoot to support its rapid propagation and spread. Moreover, the size and sedimentation of stembase were also critical for overwintering survival rate and growth of E. crassipes. Meanwhile, combined with nutrition addition in the water, responses of biomass allocation and carbon/nitrogen balance to warming and nutrition addition were also studied, elevated temperature and water eutrophication significantly promoted the growth and clonal reproduction in E. crassipes, and more biomass was allocated to aboveground fraction to support its rapid growth and clonal propagation in favorable conditions. In addition, the photosynthesis and nutrition storage of E. crassipes were promoted by increasing the N concentration in leaves and stems, while nutrient turnover was accelerated by low C/N ratio, which increased the available nutrition for E. crassipes. 2. By comparing the effects of fluctuating resources in plant communities due to warming, flooding and nutrition addition on invasive plant Alternanthera philoxeroides and native plant Jussiaea reppens, the results showed that the growth, clonal propagation and biomass allocation of invasive species A. philoxeroides performed better in response to resources fluctuation, making a competitive advantage over native plants and facilitating its invasiveness. In the meantime, photosynthetic physiology and carbon/nitrogen balance of submerged plant P. crispus in response to simulated warming and DIC concentration increasing were also studied. Effects of warming and DIC addition on P. crispus were direct opposite:spring warming reduced its photosynthetic rate and biomass accumulation, while DIC enrichment significantly improved its photosynthetic efficiency. Moreover, in combination with inorganic N addition, physiological and ecological responses of three plants (Hydrocharitaceae) to warming, DIC enrichment and inorganic N addition were investigated. Biomass of Hydrilla verticillata was significantly increased by N addition in the water column; the growth of Egeria densa was improved by the increase of carbon source, but inhibited by warming; while elevated temperature markedly reduced biomass accumulation of Elodea nuttallii. Concentrations of N and free amino acid (FAA) increased with inorganic N addition.3. A glasshouse experiment was conducted to investigate the effects of clonal integration on a non-native clonal plant Myriophyllum aquaticum subjected to spatial and temporal heterogeneity of water supply. The daughter ramets were grown with stolon connections either severed from or connected to the mother plant and provided by different combinations of amount or frequency of water supply. Clonal integration significantly improved growth and photosynthetic performance of daughter ramets. Biomass allocation to roots of offspring ramets changed with water supply to enhance the capacity of water resource’s uptake and the decrease of the maximum quantum yield of photosystem Ⅱ (Fv/Fm) with reduced amount of water supply was greatly alleviated by stolon connection. Moreover, Clonal integration facilitated stabilization of foliar N concentration and C/N ratio to support healthy growth of the ramtes. Via simulated warming by means of open top chambers (OTCs), effects of warming on emergent aquatic plant community in water-land ecotone were studied. Reponses of emergent plants to warming were species-specific. Warming increased the proportion of Scirpus yagara Ohwi and other big-and-middle-sized plants in the community, made the plants become larger, and reduced the species diversity of plant communities. Furthermore, the disappearance rate of small plants was accelerated by warming.更多还原