百花湖消落带常见植物氮磷钾营养元素含量分布特征研究

Distribution characteristics of N,P and K contents in 30 common plants from the hydro-fluctuation belt of Baihua Reservoir

于2011年9月在百花湖消落区进行随机采集,选取常见的30种百花湖消落带植物,如狗牙根(Cynodon dactylon)、牛鞭草(Hemarthria altissima)、白花三叶草(Trifolium repens)、喜旱莲子草(Alternanthera philoxeroides)、鬼针草(Bidens pilosa)、菖蒲(Acuros calamu Linn)等为研究对象,对其根、茎、叶中氮磷钾营养元素的分布进行比较研究.结果表明:大多数植物根、茎、叶中N、P、K含量表现出一致性,即K>N>P,并且N、P、K相互之间呈现出显著的正相关关系,这与该地区土壤中N、P、K的含量有着显著的关系.在同一植物不同器官中N、P、K的含量也表现出一致性,即叶>茎>根,并且根、茎、叶中的含量相互之间也呈现出现显著的正相关关系.消落区植物总体根、茎、叶的营养状况分别为低、中、高,并且地上部分的营养元素占整株植物总营养元素的平均值为80%以上.因此,收割地上部分的茎和叶,即可达到对土壤中N、P较好的处理效果.禾本科、蓼科及菊科植物中营养元素含量较低,又具有一定的耐水淹性,适宜在消落区水淹时间较长且土壤中N、P营养元素含量较低的这种特殊环境下生长.该研究揭示了百花湖消落区常见植物的营养状况,以及有助于筛选出适合消落区生长的植物,对控制水体富营养化和研究消落区生态系统的完整性有着重要的意义.

To study the distribution characteristics of N, P and K contents of plants grown in the hydro-fluctuation belt of Baihua Reservoir, 30 common plants such as Cynodon dactylon, Hemarthria altissima, Trifolium repens, Alternanthera philoxeroides, Bidens pilosa, Acuros calamus, etc., were randomly collected from the hydro-fluctuation belt of Baihua Reservoir in September, 2011. The plant roots, stems and leaves were separated for each species in order to make a comparative study on the distributions of N, K and P nutrient elements. Results showed that ① The contents of N, P and K in most plant roots, stems and leaves showed consistency of K〉N〉P and they mutually exhibited significant positive correlations, which was resulted from the contents of N, P and K in the soil of the region; ② In the different organs of the same plant, the contents of N,P and K also showed consistency that leaf〉stem〉root with significant positive correlations as well; ③ In general, the nutrition conditions in roots, stems and leaves were low, middle and high, respectively, in the hydro-fluctuation belt of Baihua Lake. In addition, overground parts of the nutritional status accounting for the total nutrition of the whole plants were more than 80% on average. Therefore, harvesting the overground parts of stems and leaves could well achieve N and P treatment in the soil; and ④ The nutrient contents of Gramineae, Polygonaceae and Compositae were low. Meanwhile, these plants also had a certain resistance to flooding, so they were suitable for growing in the hydro-fluctuation belt of the special environment. By revealing the nutrient status of plants and identifying suitable plants for hydro-fluctuation belt, this study showed great significance on controlling eutrophication and maintaining the integrity of the ecosystem in the hydro-fluctuation belt of Baihua Lake.