新疆南准噶尔荒漠优势植物的化学成分含量特点

南准噶尔荒漠 62种植物 8种元素的含量测定结果显示 ,含量算术平均值的大小顺序为 Na>K>Ca>S>P>Al>Fe>Mn,与阿拉善荒漠植物元素含量的顺序一致。其中 ,Mn、Fe、Al、Na、S的含量变异系数比 P、K和 Ca的大。植物元素含量之间相关分析结果表明 ,Fe与 Al、S与 P、Na与 S呈极显著正相关 ,表明荒漠植物对它们的吸收是协同的 ,而 Fe与 K显著负相关 ,表明植物对它们的吸收具有拮抗作用。聚类分析和排序结果说明不同生态功能群植物都有自身的元素含量特点 ,盐生植物 Na、S含量高 ,沙生植物为高 K低 Na含量功能群植物

The Characteristics of Element Content of Dominant Species in South Junggar Desert, Xinjiang

The contents of 8 elements, i.e. Na, K, Ca, S, P, Al, Fe and Mn, in 62 plant species in South Junggar desert were studied. There the climate was continental arid, with an annual precipitation of 110~220mm falling mainly in the spring and summer and a potential annual evaporation of about 2000mm. Along with the various but regular topography, various types of soil occurred in the desert. The vegetation was sparse in coverage. Dominant species of the communities were mainly of Chenopodiaceae, Compositae, Cruciferae, Leguminosae and Graminosae . They were Seriphidium borotalense, Ceratocarpus arenarius, and Petresimonia brachiata on the alluvial fans; Reaumuria soongorica and Haloxylon ammodendron on the alluvial plain, with Tamarix ramosissima often occurred in the relatively low places; Haloxylon persicum and some grasses on the fixed sandland; Kalidium foliatum, K. caspicum, Halocnemum strobilaceum and Suaeda physophora on saline land or salinized soil; Phragmites australis and Achnatherum splendens at the edge of alluvial fans where the groundwater was shallow and even seeps out on ground surface. Plant materials were collected during two periods between 1959 and 1963 and between 1989 and 1993. 400 samples of above ground parts for herbaceous species and leaves or twigs for woody plants were collected. The contents of the 8 elements were determined in normal method of chemical analysis. The results show the contents of these elements and their variations differed among the 62 species: sorted by the mean content, a sequence was Na>K>Ca>S>P>Al>Fe>Mn. This was quite similar to that in Alashan desert, Inner Mongolia. The variation coefficients of Mn, Fe, S, Na, Al, Ca, K and P were 1 875, 1 695, 1 392, 1 302, 1 062, 0 894, 0 683 and 0 491, respectively. The content of each of the elements also differed among samples of the same species and from different environments. The variation coefficient of P was relative large, even significantly larger than that among species. In contrast, the variation coefficients of K and Ca were relatively small. Similar to those found from the plants in Alashan desert, the contents of pairs of elements, i.e. Fe and Al, S and P, Na and S, in these species showed significantly positive correlation. It indicates that these desert plants absorbed these pairs of elements in coordination. The correlation coefficient between the contents of Fe and K was significantly negative, suggesting the two elements might repel each other in absorption. The results of clustering and ordination of 62 species and their communities, based on the element contents, also demonstrate that each ecologically functional group of species had its characteristics of element content. Saline plants had high content of Na and S. Plants preferring to grow on sandland had high content of K, and low content of Na, and lower ratios of Fe to Al than other plants.