作 者 ：仲启铖,杜钦,张超,王开运*
期 刊 ：生态学报 2010年 30卷 22期 页码：6135~6145
Keywords:Chongming Island, riparian plant configuration mode, spatial distribution of root system, root length density,
摘 要 ：崇明岛位于长江河口，是世界上最大的冲积岛。滨岸植物配置模式对防止侵蚀、坍塌等具有不同的作用。以崇明岛南岸4种不同的植物配置模式：芦苇（Phragmites australis）-海三棱藨草(Scirpus mariqueter)模式（PSM）、池杉（Taxodium ascendens）-芦苇-海三棱藨草模式（TAPSM）、杂交柳（Salix matsudana×alba）-芦苇-海三棱藨草模式（SPSM）及落羽杉(Taxodium distichum)-芦苇-海三棱藨草模式（TDPSM）为对象，对不同植物配置模式在低、中、高3个潮位根系空间分布进行了调查和分析。结果表明：（1）4种模式中0-40cm土层内平均总根长最大的为SPSM模式，其值为137.0 cm/cm2,平均总根长最小的为TAPSM模式(914 cm/cm2)；在3种乔木增配模式中，草本植物根长占总根长比例达94.6%-98.1%。（2）除SPSM模式外，其他3种植物配置模式根长密度均随土层加深而减小, 这3种模式根长密度最大的土层皆为0-10cm土层，分别为各自最底层根长密度的15.1倍（PSM）、4.9倍（TDPSM）和2.0倍（TAPSM）；SPSM模式在10-20cm土层根长密度最大。（3）在所有4种模式中，直径Φ＜0.1mm的微细根对总根长密度的贡献均为最大，比例从74.7%到81.7%，其次为直径0.1mm≤Φ＜1mm的细根，直径Φ≥5mm的大根极少。（4）秩和检验显示，4种模式在低、中、高3个潮位根长密度的差异并不一致。根系能够提高土壤抗侵蚀能力，研究4种模式根系空间分布特征，可以为崇明岛滨岸植物配置，建设抗蚀护滩植被带提供科学依据。
Abstract:Chongming Island, which locates at Yangtze River mouth, is the largest estuary alluvial island in the world. Plant configuration mode in riparian banks plays different functions on decreasing soil erosion and bank collapse. Four plant configuration modes located at collapsing banks of south coast of Chongming Island were studied in the paper, the four modes includes Phragmites australis + Scirpus mariqueter mode (PSM), Taxodium ascendens + Phragmites australis + Scirpus mariqueter mode (TAPSM), Salix matsudana×alba+ Phragmites australis + Scirpus mariqueter mode (SPSM) and Taxodium distichum + Phragmites australis + Scirpus mariqueter mode (TDPSM). The spatial distribution of root system in four modes at different beaches were investigated and analyzed. The results showed: (1) The largest mean total root length in 0-40 cm soil layer happened in SPSM, and the value was 137.0 cm/cm2, the smallest value (91.4 cm/cm2) happened in TAPSM. The ratio of herbaceous root length ranged from 94.6% to 98.1% in three arboreal and herbaceous mixed modes. (2) Except SPSM mode, root length density (RLD) of other three plant configuration modes generally decreased along with the increase in depth, and all the three modes had their largest RLD in top 10 cm soil layer, with 151 times(PSM), 4.9 times(TDPSM) and 2.0 times (TAPSM) of the bottom layer, respectively; As to SPSM, the largest RLD happened in the range of 10-20 cm in depth. (3) Very fine roots (diameter Φ＜0.1mm) contributed most to total RLD in all four modes, with the ratio ranging from 74.7% to 81.7%. The next portion were fine roots (diameter 01mm≤Φ＜1mm), and large roots (diameterΦ≥5mm) were rarely found. (4) Rank sum test showed: The differences in RLD were not uniform among four modes in lower, middle and higher beaches. Roots can improve soil anti-erosion capacity. The researches on spatial distribution of root system of four plant modes could provide some scientific basis for construction of riparian plant configuration modes, and protecting vegetation zone for anti-erosion in the bank of Chongming Island.
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