喀斯特石漠化山区苔藓植物水分吸收特征

[目的]探究贵阳市花溪区石漠化地区5种优势种黑扭口藓(Barbula nigrescens)、美灰藓(Eurohypnum leptothallum)、卷叶湿地藓(Hyophila involuta)、小牛舌藓全缘亚种(Anomondon minor subsp.integerrimus)、北方紫萼藓(Grimmia decipiens)的水分吸收特征,为喀斯特石漠化地区利用苔藓植物开展水土保持工作提供理论支撑。[方法]采集样品120份,运用经典形态分类法进行鉴定;测定其生物量、饱和吸水率、吸水量、最大吸水速率(Vmax)、吸水速率常数(Km)和叶片展开时间。[结果](1)5种苔藓植物间的生物量、吸水量和饱和吸水率差异较大,最大吸水速率差异小;生物量为10.36~114.51g/m2;饱和吸水率为675.43 6%~1 125.41%;吸水量为98.21~766.13g/m2;Vmax为35.59~51.28g/(g·min);Km为69.97~101.99g;叶片展开时间为35.9~86.1s。(2)生物量和吸水量呈正极显著相关;吸水量和盖度、Vmax和Km呈正相关;Km和叶片展开时间呈负相关。[结论]在喀斯特石漠化地区干旱缺水的环境条件下,苔藓以独特的水分吸收和利用方式适应这种恶劣的环境。石生苔藓为适应该地区的先锋植物。

Water Absorption Characteristics of Bryophytes in Karst Rocky Desertification Area

[Objective] The water absorption characteristics of five dominant bryophyte species at rocky desertification area of Huaxi district in Guiyang City, included Barbula nigrescens,Eurohypnum leptothallum,Hyophila involuta, Anomondon minor subsp. integerrimus and Grimmia decipiens were studied, in order to provide theoretical support for soil and water conservation work using bryophytes in karst rocky desertification area.[Methods] Totally 120 samples were collected and the taxonomic identification were completed with morphological classification method. After that, biomass, saturated water adsorption rate, water adsorption quantity, the maximum water absorption rate(V_max), the constant of water absorption(K_m) and leaf expanding time of those samples were measured and compared among the five moss species.[Results] (1) There was large difference of biomass, water adsorption quantity and saturated water adsorption rate among the five species, and the maximum water absorption was less different. The ranges of biomass, saturated water adsorption rate, water adsorption quantity, V_max, K_m and leaf expanding time were 10.36~114.51 g/m², 675.43%~1 125.41%, 98.21~766.13 g/m², 35.59~51.28 g/(g·min), 69.97~101.99 g, 35.9~86.1 s, respectively; (2) It was showed that the correlation between biomass and saturated water adsorption quantity was positive. Water adsorption quantity had positive correlations with cover degree, the K_m and V_max. The negative correlation was found between K_m and leaf expansion time.[Conclusion] Bryophytes are adaptable to harsh environment, which had serious water shortage like karst rocky desertification area, with an unique way of water absorption and utilization. Stone-bryophytes can act as the pioneer plants which is highly adaptable to the karst rocky desertification area.