云南树干附生苔藓生物量沿纬度及海拔梯度的变化特征

Biomass of Bole Bryophytes along the Latitudinal and Altitudinal Gradients in Yunnan

为探讨不同森林群落树干附生苔藓的生物量及其组成沿纬度、海拔梯度的变化格局,采用样地调查法,对云南热带(勐腊县)、亚热带(镇沅县)及亚高山(丽江玉龙县)不同海拔不同森林类型中树干附生苔藓的总生物量、优势组分生物量和不同生活型组分生物量的分布格局进行调查研究。结果表明:(1)随着纬度、海拔的升高,3种代表性森林类型单位面积树干附生苔藓植物的生物量上升,以丽江亚高山针叶林最高(3.57 g·400 cm^(-2));镇沅亚热带常绿阔叶林次之,为2.00 g·400 cm^(-2);勐腊热带森林最低,仅为0.53 g·400 cm^(-2)。(2)3种森林类型树干附生苔藓植物的优势组分中无相同物种。(3)随着纬度、海拔的上升,单位面积附生苔藓植物平均生物量上升,优势种类的相对生物量占比有所下降,勐腊热带森林、镇沅哀牢山亚热带常绿阔叶林和丽江玉龙雪山亚高山针叶林树干附生苔藓优势组分的生物量分别占总生物量的92.3%、75.6%和85.2%。(4)随着纬度和海拔的上升,3种森林类型树干附生苔藓植物群落不同生活型组分的生物量存在明显的分异规律。细平铺型、扇形和丛集型分别为勐腊热带森林、镇沅哀牢山亚热带常绿阔叶林和丽江玉龙雪山亚高山针叶林的优势附生苔藓生活型。

Epiphytic bryophytes are structural components in tropical and sub-tropical forests. To understand variation of the biomass of bole bryophytes along the latitudinal and altitudinal gradients, the biomass of bole bryophytes in tropical forests（Mengla）, sub-tropical forests（Zhenyuan） and sub-alpine forests（Lijiang） in Yunnan, SW China were carried out. The results showed：（1） Biomass of bole bryophytes were significantly different along the latitudinal and altitudinal gradients. The lowest（0.53 g·400 cm-2） and the highest（3.57 g·400 cm-2） biomass occurred in the tropical forest of Mengla and the subalpine coniferous forest of Lijiang, respectively.（2） There was no dominant species shared among the three forests.（3） The biomass proportion of dominant component declined along the altitude gradients,they were 92.3%（Mengla）,75.6%（Zhenyuan）and 85.2%（Lijiang）of the total biomass.（4）Smooth mat,fan and turf were the dominant life-forms in tropical forests,sub-tropical evergreen broadleaved forests and sub-alpine coniferous forests,respectively.The results would provide preliminary insights on the structure,function and dynamics in the mountain forest ecosystems.