两种草本植物光合生理与生化特性对植被混凝土水泥含量的响应

Responses of photosynthesis-related physiological and biochemical characteristics in two herbaceous plants to cement content in vegetation concrete matrix

植被混凝土生态防护技术中水泥含量对于边坡稳定性和物种的定居生长均有着重要的影响.为探讨冰草和垂穗披碱草在植被混凝土生态防护技术应用中的适宜水泥含量,测定两种草本植物光合生理与生化特性对植被混凝土水泥含量的响应.结果显示,水泥含量对两种草本植物的光合生理与生化指标均有显著的影响.冰草、垂穂披碱草幼苗的净光合速率(Pn)均随着水泥含量的上升先上升后下降,最大值分别出现在6%、8%水泥处理组(分别为对照组的1.45倍和2.39倍),气孔导率(Cs)、胞间CO2浓度(Ci)均与Pn有着相似的趋势.光能利用效率、水分利用效率均随着水泥含量的上升先上升后下降,且冰草均在6%水泥处理组最大,分别为对照组的2.13倍和1.45倍;而垂穂披碱草均在8%水泥处理组最大,分别为对照组的2.39倍和2.34倍.叶绿素、脯氨酸、可溶性糖含量也均随着水泥含量的上升先上升后下降.综合分析比较两种草本植物光合特性和生理生化参数,垂穗披碱草对水泥含量最高耐受含量为6%-10%,冰草为4%-8%,垂穗披碱草对水泥含量的耐受度高于冰草.冰草和垂穂披碱草均具有较好的抗逆性能,可应用于西南高山亚高山地区地区边坡的生态恢复,在植被混凝土生态恢复实际中应结合边坡的稳定性需要再适当调整水泥含量.

The cement content in vegetation concrete matrix is the most important factor influencing slope stability and plant growth.We tested photosynthesis-related physiological and biochemical characteristics in two herbaceous species(Agropyron cristatum(L.)Gaertn and Elymus nutans Griseb),in the alpine and subalpine permafrost regions of southwestern China with different vegetation concrete matrices to determine their utility in concrete biotechnical slope(CBS)technology.The results showed that photosynthesis-related physiological and biochemical characteristics were significantly affected by the cement content of the matrix.With increasing cement content,the Pn of A.cristatum and E.nutans firstly increased and then decreased.The highest values appeared in 6%and 8%cement treatment groups,which were 1.45 times and 2.39 times that of the control group,respectively.Similar trends were found for Cs and Ci.Light energy utilization efficiency(LUE)and water use efficiency(WUE)decreased first and then decreased with the increase in cement content.A.cristatum had the largest in the 6%cement treatment group,which were 2.13 times and 1.45 times that of the control group,respectively;whereas E.nutans had the largest in the 8%cement treatment group,which were 2.39 times and 2.34 times of the control group,respectively.Chlorophyll,proline,and soluble sugar content also firstly increased and then decreased with increasing cement content.The analysis and comparison between the two herbaceous plant species indicated that the highest tolerated cement content for E.nutans and A.cristatum was 6%-10%and 4%-8%,respectively.The adaptation of E.nutans to cement is better than that of A.cristatum.In conclusion,A.cristatum and E.nutans are suitable candidates in the application of CBS for the ecological restoration of slopes in the alpine and subalpine permafrost regions of southwestern China.The appropriate cement content should be selected according to slope stability requirements.