Growth and morphological responses of four helophyte species in an experimental water-depth gradient
Growth and morphological responses of four helophyte species in an experimental water-depth gradient
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DOI：
10.1016/0304-3770(96)01025-x
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发表时间：
1996-06-01
期刊：
影响因子：
1.8
通讯作者：
vanderVelde, G
中科院分区：
文献类型：
--
作者：
Coops, H;vandenBrink, FWB;vanderVelde, G
4种蕨类植物（2种禾本科植物，即Phalaris arundinacea L.和Phragmites australis (Cav.)）的岸线分布。指标。研究了两种海藻类（Scirpus maritimus L.和S. lacustris L.）在水深梯度下的生长响应。相对于平均水位（平均边缘深度69 +/- 19 cm），湖杉木林分的深度小于芦苇（45 +/- 20 cm）、海杉木（36 +/- 8 cm）和蝴蝶兰（25 +/- 8 cm）林分。通过在室外盆地5个不同水深种植4种植物，连续2年测定其形态参数和生物量分布，研究其生长对不同水深梯度的响应。在30 cm水深下，凤仙花（Phalaris arundinacea）生物量减少，而芦苇（Phragmites australis）和海苔（S. maritimus）在80 cm水深下生物量减少。即使在80 cm水深处，湖螺的生物量也没有减少。研究表明，在较深的水中，每种物种的地上：地下生物量比都有所增加；禾本科物种生物量分布的变化发生在极浅水，与苏纲物种相反。四种植物的平均茎基直径均随水深的增加而增加。平均茎长随水深的增加而增加。随着水深的增加，丝状纲物种的茎伸长最大。禾本科植物在淹没节处不定根的形成增强。禾本科和苏纲各类群对水深响应的相似性最大。这些响应反映了物种在水深梯度上的分带性：相对深水区为湖螺，较浅水区为芦苇和海螺，极浅水区为环蕨。
The distribution on shorelines of four helophyte species (two gramineous species, viz. Phalaris arundinacea L. and Phragmites australis (Cav.) Trin. ex Steudel and two cyperacean species, viz. Scirpus maritimus L. and S. lacustris L.) was studied in relation to growth responses in the water-depth gradient. Stands of S. lacustris were found at fewer depths relative to the mean water level (average fringe depth 69 +/- 19 cm) than stands of Phragmites australis (av. 45 +/- 20 cm), S. maritimus (av. 36 +/- 8 cm) and Phalaris arundinacea (av. 25 +/- 8 cm). The growth responses to a gradient of water depth were studied by planting the four species at five distinct water depths in outdoor basins, and determining morphological parameters and biomass distributions of the species grown for two consecutive years. The biomass of Phalaris arundinacea was reduced below 30 cm water depth, while Phragmites australis and S. maritimus showed reduced biomass at 80 cm water depth. S. lacustris showed no biomass reduction even at 80 cm water depth. An increased above-ground: below-ground biomass ratio in deeper water was demonstrated for each of the species under study; however, the modification of biomass distribution in the gramineous species occurred abruptly in very shallow water contrary to the cyperacean species. Mean basal stem diameter increased with water depth in all four species. Mean stem length increased with water depth in three of the four species. Stem elongation with increasing water depth was strongest in the cyperacean species. The gramineous species showed enhanced formation of adventitious roots at submerged nodes. The similarity of responses to water depth was greatest within each of the groups of gramineous and cyperacean species. The responses reflect the zonation of the species along the water-depth gradient: S. lacustris in relatively deep water, Phragmites australis and S. maritimus in shallower water, and Phalaris arundinacea in very shallow water.