Tramp-tolerance characters of C299 of Cynodon dactylon (L.) Pers. and two hybrids ‘Tifdwarf’ and ‘Tifgreen’ of C. dactylon×C. transvaalensis Burtt-Davy were evaluated under the light-tramp, medium-tramp and s...Tramp-tolerance characters of C299 of Cynodon dactylon (L.) Pers. and two hybrids ‘Tifdwarf’ and ‘Tifgreen’ of C. dactylon×C. transvaalensis Burtt-Davy were evaluated under the light-tramp, medium-tramp and serious-tramp with a 75 kg tramper. The results indicated that tramp caused leaf blades of C299 narrower, color lighter and turf quality lower; but the turf height and internode length of C299 with different rolling intensity were not obviously different from that of ‘Tifgreen’. The turf quality of C299 under serious tramp is higher than that of ‘Tifgreen’ and ‘Tifdwarf’. C299 had stronger ability to recover in vertical direction than that of ‘Tifgreen’ and ‘Tifdwarf’ under the tramp. The results show that C299 has the high turf quality and tramp tolerance charater.展开更多
文摘剧烈的土壤侵蚀和库岸坍塌是三峡水库消落带的主要生态环境问题之一，而植被恢复是治理消落带的关键措施之一，植物的消浪固土能力是消落带适宜植物配置的重要依据。为了探讨三峡水库消落带典型草本植物狗牙根（Cynodon dactylon （L.） Pers.）和牛鞭草（Hemarthria altissima （Poir.） Stapf et C. E. Hubb.）的消浪减蚀效应，进行了植物消浪和波浪冲刷的水槽概化模拟试验。结果表明，2种植物的消浪效应有较大差异，在周期较长（1.2～1.5 s）时狗牙根平均消浪系数为0.54，明显高于牛鞭草（0.37）；而在周期较短时（0.8～1.0 s）则2种草本消浪性能相当，消浪系数均介于0.15～0.30之间。在同样的试验条件下，狗牙根、牛鞭草平均侵蚀模数分别为17.63、57.28 g/（m2＆#183;min）。2种草本的减蚀效应均在89%以上，最高可达98.59%。植物的减蚀效应是其地上部分和地下根系的综合作用结果，其中牛鞭草根系的固土贡献率在91%以上，而地上部分仅为7.4%～8.6%；狗牙根根系固土贡献率（71.2%～76.2%）显著低于牛鞭草，但其地上茎干部分贡献率（23.8%～28.8%）要显著高于牛鞭草（P＜0.05）。可见2种植物都有较好的消浪减蚀效应，总体上狗牙根的消浪能力和综合减蚀效果均要略强于牛鞭草。波浪大小和周期、植被盖度、植物地上部分和根系形态对消浪减蚀效应有重要影响。该研究结果可以为三峡水库消落带的植被恢复和水土保持工程提供一定的参考依据，并可适当的推广到其他水库或湖泊消落带。
文摘Tramp-tolerance characters of C299 of Cynodon dactylon (L.) Pers. and two hybrids ‘Tifdwarf’ and ‘Tifgreen’ of C. dactylon×C. transvaalensis Burtt-Davy were evaluated under the light-tramp, medium-tramp and serious-tramp with a 75 kg tramper. The results indicated that tramp caused leaf blades of C299 narrower, color lighter and turf quality lower; but the turf height and internode length of C299 with different rolling intensity were not obviously different from that of ‘Tifgreen’. The turf quality of C299 under serious tramp is higher than that of ‘Tifgreen’ and ‘Tifdwarf’. C299 had stronger ability to recover in vertical direction than that of ‘Tifgreen’ and ‘Tifdwarf’ under the tramp. The results show that C299 has the high turf quality and tramp tolerance charater.
文摘为探讨干湿循环对三峡消落带狗牙根磷释放的影响,以三峡典型支流-澎溪河为例,选取上游(渠口镇)和下游(双江镇)两个水文断面, 150、160、170 m三个水位高程调查了狗牙根分布特征,并于干湿循环和持续淹水两种水文情势,15-25-35-25-15℃连续温度变化下进行培养,测定了水-土(W-S)、水-狗牙根(W-C)和水-土-狗牙根(W-S-C)三种体系下水中磷含量随时间变化。结果表明:狗牙根生物量随消落带水位高程降低而下降,表现为170m(1.62 kg·DW·m^-2)>160 m (0.85 kg·DW·m^-2)>150 m (0.19 kg·DW·m^-2)。在整个培养阶段,三种体系水中磷含量均随培养时间的延长而增加,表现为W-S-C>W-C>W-S体系,其释放动力学过程符合y=axb幂函数模型。与持续淹水相比,干湿循环影响下W-S-C体系中狗牙根磷释放量较低,可见,干湿循环有利于降低消落带狗牙根磷释放,降低三峡支流水体富营养化风险。
