不同改良措施对退化高寒草甸土壤种子库的影响

利用萌发法研究了甘南退化高寒草甸不同改良措施(经综合恢复即围封+划破草皮+补播+灭鼠(ESRD)、围封+灭鼠(ED)、围封(E))下土壤种子库的特征。结果表明,在所调查的样地中共统计到35种植物,隶属18科29属。对甘南退化高寒草甸采取综合恢复(ESRD)时,土壤种子库物种数趋于增加,比ED高出16.9%,比E高出63.9%。ESRD措施下土壤种子库密度为2451.5粒/m2,比ED高出354.8粒/m2,比E高出957.1粒/m2;杂类草所占的比例也有所减少,比ED低19.3%,比E低26.2%;物种的丰富度和多样性指数均低于其他两种措施。3组改良措施鼠丘种子库密度依次为ESRD(938.1粒/m2)ED(762.8粒/m2)E(719.1粒/m2);鼠丘上禾本科物种所占比率为综合恢复ESRD(23.26%)ED(12.31%)E(11.92%)。ESRD改良下鼠丘上的物种的丰富度和多样性指数均小于其他组。说明对退化高寒草甸草地及时进行综合恢复和灭鼠以及对鼠丘进行补播是改良天然退化草地的重要手段。

Effects of various rangeland improvements on soil seed bank on degraded alpine meadow

The characteristics of soil seed bank in degraded alpine meadow in Ganan under 3 managements, including enclosure + sward cleavage + reseed + rodent control (ESRD),enclosure + rodent control (ED), and enclosure (E)were studied by using germination method in greenhouse.The results showed that there were 35 species of plants which belong to 29 genera and18 families.After the application of comprehensive re-covery treatment,the plant species of soil seed banks was 16.9% and 63.9% higher than that of treatment ED and treatment E.The soil seed density of comprehensive recovery treatment was 2 451.5 grains/m2 ,which was 354.8 grains/m2 and 957.1 grains/m2 higher than that of treatment ED and treatment E.The proportion of forbs in treatment ESRD was 19.3% and 26.2% lower than that of treatment ED and treatment E.The richness diversity of species were lower than that of other two treatments.Under different managements,the rank of soil seed density in mounds was ESRD (938 grains/m2 )>ED(763 grains/m2 )>E (719 grains/m2 ).The rank of percentage of gramineous plants on mounds was ESRD(23.26%)>ED(12.31%)>E(11.92%).The richness and diversity index of species on mounds of treatment ESRD were lower than that of other two treatments.It could be concluded that the comprehensive recovery method and rodent control as well as reseeding on rodent mounds were better for the improvement of degraded alpine meadow.