人工培育苔藓结皮生长特征对浇水间隔期的响应

Response of Growth Characteristics of Artificially Cultivated Moss Crusts to Watering Interval

苔藓结皮是由苔藓、微生物和土壤形成的复合体。所需苔藓种源不足一直是野外工程化生物结皮恢复的瓶颈。土壤水分是限制苔藓结皮繁育的重要因素,分析浇水间隔期对苔藓结皮生长的影响,可为苔藓结皮的人工培育提供理论依据。在科尔沁沙地开展5个浇水间隔期(每次浇水间隔3 d、5 d、7 d、10 d、15 d)苔藓结皮培育试验,测定苔藓植物的植株高度、植株密度、覆盖度,以及苔藓结皮层的厚度和干重,分析苔藓结皮生长特征对浇水间隔期的响应。结果表明:(1)苔藓结皮具有较强的耐旱性,浇水间隔期5 d条件下苔藓结皮生长状况最优,苔藓植物的植株高度、植株密度、覆盖度以及结皮层的厚度和干重均最大,分别为2.2 mm、12.64株·cm^(-2)、94%、2.6 mm、0.32 g·cm^(-2);苔藓结皮在轻度干旱条件下的生长特征优于过度湿润环境,其培育和拓殖在干旱半干旱退化生态系统的近自然恢复中具有较大的应用潜力;(2)10 d以上的干旱期对苔藓结皮的生长发育有显著影响,相比浇水间隔期5 d、15 d的苔藓植物的植株高度、植株密度、覆盖度、结皮层厚度及结皮层干重分别下降59.4%、41.1%、25.5%、43.3%和62.5%。综合考虑结皮生长发育与浇水成本,科尔沁沙地苔藓结皮培育较合理的浇水间隔期为5~10 d。

Moss crusts are complex formed by moss,microorganisms and soil.The lack of moss provenance is a bottleneck problem in the recovery of biological crusts in the field.Soil moisture is a limiting factor for the growth of moss crusts.It can provide a theoretical basis for the cultivation of artificial moss crusts to analyze the effect of watering interval on the growth of moss crusts.In Horqin Sandy Land,a randomized experimental design was carried out with five watering intervals(3 d、5 d、7 d、10 d、15 d)in order to measure the plant height,plant density and coverage of bryophyte,as well as the thickness and dry weight of the moss layer and analyze the response of growth characteristics of moss crusts to watering interval.The results showed that:(1)Moss crusts in Horqin Sandy land had strong drought tolerance.Under the condition of watering interval for 5 d,the growth of moss crusts was the best,and the height,density,coverage,thickness and dry weight of moss crusts were the largest,which was 2.2 mm,12.64 plants·cm^(-2),94%,2.6 mm and 0.32 g·cm^(-2),respectively.The growth characteristics of moss crusts under mild drought condition were better than those in excessive humid environment,and their cultivation and colonization had great application potential in the near-natural restoration of arid and semi-arid degraded ecosystems.(2)The drought period over 10 days significantly influenced the growth and development of moss crusts.Compared with the watering interval for 5 d,the height,density,coverage,thickness and dry weight of moss crusts with the watering interval for 15 d decreased by 59.4%,41.1%,25.5%,43.3%and 62.5%,respectively.Considering the growth and development of crusts and watering cost,the reasonable watering interval of moss crusts cultivated species in Horqin Sandy Land is 5-10 days.