矿质元素是植物生长发育必需的营养,为明确其在退化草地植物中发生的变化,选择青海湖北岸同类型退化草地和围栏封育草地为试验样地,通过对各类型草地植物中钾、钙、镁等矿质元素的对比分析,阐述退化草地和封育草地植物中矿质元素特征,揭示草地退化与其中矿质元素营养之间的相关关系.结果表明:退化草地与封育草地上植物和土壤中矿质元素含量具有明显差异,退化草地较封育草地上植物和土壤中矿质元素营养具有蓄积增加的趋势,这是草地退化的结果,是退化草地“加速”退化的原因,是生物矿质元素营养的一种“饥饿效应”,也是生物对环境变化的一种“应急”响应.随着海拔高度的逐渐增加,青海湖北岸自南向北退化草地植物中矿质元素营养蓄积具有逐渐增大的特征,因为海拔低处的自然环境更有利于大多数植物的生长发育.%Natural grassland degradation in drainage areas of Qinghai Lake is very serious. The mineral elements are essential nutritions for plant growth. To illuminate the dynamics of mineral elements in plants with grassland degradation, sample materials were collected from degraded grassland and fence- enclosed grasslands on north banks of Qinghai Lake. Mineral elements (K, Ca and Mg) of plants from different types of both degraded and enclosed grassland are investigated through comparative analysis to reveal the correlation between grassland degradation and mineral nutrition. Results show that the mineral contents of plants and soil in degraded grassland are quite different from those in enclosed grassland. Compared with the enclosed grassland, mineral elements in degraded grassland plants and soil have a trend to accumulate, which is a result of grassland degradation. And then this accumulation accelerates grassland degradation. Mineral element accumulation of degraded grassland plants is a "Biological effects of starvation" and an "e-mergency" response for environmental variations.
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