芦芽山鬼箭锦鸡儿灌丛营养特征及土壤养分分布规律

Nutritional characteristics of Caragana jubata shrub and distribution patterns of soil nutrients in Luya Mountain.

研究了芦芽山自然保护区亚高山草甸带鬼箭锦鸡儿(Caraganajubata)灌丛营养成分季节性变化和土壤养分分布规律.结果表明,鬼箭锦鸡儿具有很高的营养价值,粗蛋白含量达20·27%,粗纤维含量33·83%,灰分5·12%,同时含有丰富的Ca、Fe、Mn等中微量元素,是亚高山草场家畜的优质饲料来源.鬼箭锦鸡儿营养成分呈明显的季节性变化规律:从5月开始,随着灌丛生长发育,体内粗蛋白、灰分和矿质元素含量呈上升趋势,7月(开花期)达到最高,然后逐步降低.为适应海拔高、气温低、土层薄的亚高山草甸带生境,鬼箭锦鸡儿灌丛周围的土壤养分向灌丛中心聚集,灌丛中心的土壤电导率、有机质、全氮、速效磷和有效钾分别较灌丛边缘高18·8%、16·4%、18·7%、16·6%和8·4%,形成了明显的"肥岛效应".鬼箭锦鸡儿灌丛根际土壤有机质、全氮出现富集,有效磷、速效钾和速效铁、锰在根际周围出现明显亏缺,表明鬼箭锦鸡儿具有高效固氮和吸收利用土壤养分的能力.

The study on the nutrient components of Caragana jubata shrub and the distribution patterns of soil nutrients in Luya Mountain of Shanxi Province showed that C. jubata was a valuable feeding plant, which contained 20. 27% of crude protein and 5. 12% of ash with abundant Ca, Fe and Mn. The crude protein, ash, and mineral element contents increased from May and achieved the highest in July when C. jubata was at flowering stage, and then declined. To adapt to the habitat in subalpine meadow with high altitude, low temperature and thin soil layer, C. jubata had ＂fertility island＂ effect. The electric conductivity and the contents of organic matter, total N, available P and available K in the center of ＂fertility island＂ increased by 18.8% , 16.4% 18.7% , 16.6% and 8. 4% , respectively, compared with those in the edge of the ＂fertility island＂. The organic matter content and total N content in rhizosphere increased, while the contents of available nutrients such as P, K, Fe and Mn decreased, suggesting that C. jubata had high capability of N fixation and nutrients uptake.