沙地冷蒿种群的耐牧机理研究初报

Study on the Grazing Resistance Mechanism of Artemisia Frigida Population

通过调查冷蒿的生物学特性，并以４种不同处理实验研究了耐牧性。处理方法分别为第１组模拟轻牧，剪去植株高度的一半（Ｔ１）；第２组模拟重牧，把植株地上部分全部剪掉（Ｔ２）；第３组埋土３～５ｃｍ（Ｔ３），以模拟沙质草场疏松的地表易被牲畜践踏活化而掩埋植物；第４组做对照（Ｔ４）。试验结果证明，春季对地上部分剪除不影响以后的营养生长和生殖枝的形成发育，但是７月以后做剪除处理则对其营养生长不利，对生殖枝的形成影响更大。生长季多次剪枝可获得更大生物量，不同处理组平均每株的地上部分收获生物量（干重）分别是２５．２ｇ（Ｔ１），２７．４ｇ（Ｔ２），２４．７ｇ（Ｔ３）和２２．０ｇ（Ｔ４）。冷蒿枝条密集，在无干扰条件下，平均每株有枝条近百枝。植株地上部被剪除后，不定芽萌发力强，１ｃｍ的残枝上可以萌芽２～４个。枝条的基部极易生不定根形成新植株。有性繁殖与无性繁殖并存保证了种群更新。

Artemisia frigida population was studied with 4 different treatments at the Ecological Rehabilitation Plot and Desertified Rangeland Rehabilitation Plot of Naiman Desertification Research Station. Sixty plants were divided into 4 groups randomly in spring and treated as ( T 1 ) half cut of the branch from the middle ; ( T 2 ) cut of the branch from the ground; ( T 3 ) cover sandy soil 3￣5 cm on plants and ( T 4 ) contrast group. The examination results show that there is no negative influence on A. frigida vegetative growing and progenitive branch formulation of cutting in spring. But the significant negative influence on growing of cutting in summer. The biomass of A.firigida from more times cutting is higher than that from once cutting during the growth season. The different treatments produced the biomass of one plant as follows: 25.2 g( T 1 ), 27.4 g( T 2 ), 24.7 g ( T 3 ) and 22.0 g( T 4 ) respectively. It is proved that A. frigida is a kind of semi bush with thick branches and dense adventitious buds on the branch, normally, 2￣4 sprouted new buds of each 1 cm stubble after pruning. The adventitious roots grow out from old prostrated branch and formed a new plant. A.frigida propagated population by both vegetative and generative reproduction.