| 摘要: |
| 在三江平原湿地植物生长季节里,选择该区分布最广、面积最大且最具有代表性的毛果苔草(Carex lasioncarpa)-狭叶甜茅(Glyceria spiculosa)群落和小叶章(Deyeuxia angustifolia)群落为研究对象,逐月测定两类湿地群落生物量,并对植物样品分别用钼锑抗比色法和原子吸收法测定其P、K含量。在此基础上,探讨了两类湿地群落的P、K积累量及其生物循环特征。结果表明,三江平原不同的植物群落以及同一群落的不同器官,其P、K元素积累量不同,而且都有明显的季节变化。根是群落中P、K元素的最大贮存器官,其P、K积累量占总量的80%左右。湿地群落中K的吸收量、归还量、存留量、现存量和表土贮量都大于P的对应值,同时K的利用系数和循环系数均大于P,毛果苔草-狭叶甜茅群落K的吸收系数大于P,而小叶章群落K的吸收系数小于P。 |
| 关键词: 营养元素P、K,积累,动态,生物循环,湿地植物群落,三江平原 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目,49771002号;重庆市高等学校优秀中青年骨干教师资助计划,2005—2007 |
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| ACCUMULATION AND BIOLOGICAL CYCLING OF P AND K IN WETLAND COMMUNITIES IN SANJIANG PLAIN |
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HE Tai-Rong1, YANG Yong-Xing2
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1.School of Geographical Science, Chongqing Normal University, Chongqing, 400047;2.School of Environmental Science and Engineering, Tongji University, Shanghai, 200093
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| Abstract: |
| Sanjiang Plain is the most concentrated region of freshwater wetland in China, where Carex lasiocarpa-Glyceria spiculosa wetland and Deyeuxia angustifolia wetland are two typical and representative wetland types. They distribute widely with large coverage of the area. At present however, no reports about elements P and K accumulation, dynamics and their biological cycling are available regarding the two wetland communities to our best knowledge.
To fill up the blank in the field, we carried out this project during the growth season of the wetland plants, and sampled representative C. lasiocarpa-G. spiculosa community and D. angustifolia community for the study. The plant biomass was measured monthly using quadrate method. Elements P and K concentrations of all the samples were measured with colormetric method and atomic absorption spectrometry method, and their biological cycling in the two communities were studied.
The root is the major storage part of P and K for all wetland plants, taking 83.83% and 78.00% to the total mass of C. lasiocarpa-G. spiculosa community. The corresponding values of D. angustifolia community were 82.41% and 83.40% respectively. The K accumulation was much higher than that of P.
On the other hand, elements P and K accumulation showed obvious seasonal changes in a down-bending cubical parabola curve for the two wetland communities. Similar seasonal patterns were also found for the stems and leaves, but with different peak values, indicating that at the initial and end stages of the plant growth there were high accumulation of the elements. The minimum value appears in late June. The total accumulation presents also an ascending trend in whole season.
For element, its annual amounts of absorption, return, and remain, and the amount in the top soils, are bigger than those of P in the two wetland communities. Utilization coefficient and recycling coefficient of K are also bigger than those of P. The absorption coefficient of K is larger than that of P in C. lasiocarpa-G. spiculosa community, but smaller than that of P in D. angustifolia community. |
| Key words: Nutrient element (P and K), Accumulation, Seasonal dynamics, Biological cycling, Wetland plant community, Sanjiang Plain |
