衰败梭梭林下土壤结皮发育过程中水分补给对黄花补血草种子萌发的影响

通过模拟3种土壤结皮和人工控制4种供水量，研究衰败梭梭林下土壤结皮发育过程中水分补给对黄花补血草种子萌发的影响。结果表明:1）同一供水量不同结皮条件下，土壤含水量基本表现为:风沙土>生物结皮>物理结皮。2）不同处理下黄花补血草均在播种第5天开始出苗，物理结皮供水15 mm（B2-4）时出苗最迅速，风沙土供水5 mm(B1-2) 时出苗最缓慢。随着供水量的减小，同一结皮下的出苗进程逐渐缓慢并且其出苗率逐渐降低。3）3～10 mm供水时，黄花补血草出苗率表现为:生物结皮>物理结皮>风沙土。同一结皮下，供水15 mm时的出苗率均最高，除物理结皮供水15 mm外，其他样地出苗率高的幼苗死亡率也较高；4）同一供水条件下，出苗速率基本均表现为:生物结皮>物理结皮>风沙土。同一结皮不同灌水量下，15 mm灌水量时的出苗速率均最高。同一结皮不同供水量下，黄花补血草死亡速率随供水量的增加呈下降趋势。由此可见，风沙土对水分的保持效果最好，生物结皮保水效果高于物理结皮，结皮与水分相互作用影响种子萌发。

Effects of Soil Crust and Water Supply on Seed Germination of Limonium aureum under Decayed Haloxylon ammodendron Forest

By simulating 3 kinds of soils and 4 volumes of water supply,the effects of soil crust type and water supply quantity (WSQ) on the seed germination of Limonium aureum that were growing under the decayed Haloxylon ammodendron forest were studied.The results showed that 1) under the same WSQ,the moisture contents of the soils with different crusts basically were in the order of sandstorm soil>soil with biological crust>soil with physical crust.2) Under the different treatments,the seeds of L.aureum all emerged on the 5^th day after sowing.The most rapid seedling emergence was found in the soil with physical crust,and the WSQ was 15 mm (B2-4).The seedling emergence was the slowest in the sandstorm soil with the WSQ of 5 mm (B1-2).With the decrease of WSQ,the seedling emergence process gradually became slow,and the seedling emergence rate was gradually decreased.3) When the WSQ was 3-10 mm,the seedling emergence rate was in the order of biological crusts>physical crusts>sandstorm soil.Under the same crust,the seedling emergence rate was the highest when the WSQ was 15 mm.Except for the physical crust wit 15 mm WSQ,high seedling mortality were observed in other sample plots with high seedling emergence.4) Under the same water supply condition,the seedling emergence rate was basically in the order of biological crust>physical crust>sandstorm soil.Under different WSQ of the same crust,the seedling emergence rate was the highest with 15 WSQ.The seedling mortality decreased with the increase of WSQ.It was concluded that the sandstorm soil had the best water retention effect,the retention effect of biological crust was higher than the physical crust,and crust type and water supply presented interaction effects on the seed germination of L.aureum.