沼泽湿地恢复演替过程中朝天委陵菜间隔子性状与分枝强度的关系

The relationship between spacer characteristics and branching intensity of Potentilla supina during the restorative succession periods in a marsh wetland

间隔子和分株影响克隆植物的空间分布和资源获取,二者之间关系的研究有助于理解克隆植物的生态适应机制。按照恢复时间设置I(5a)、II(15a)、III(25a)3个梯度,研究了永昌北海子国家湿地公园沼泽湿地恢复演替过程中朝天委陵菜(Potentilla supina)间隔子长度、直径与分枝强度之间的关系。结果表明:随着沼泽湿地恢复演替的进行,湿地群落的高度、盖度和生物量逐渐增大,土壤含水量、有机质逐渐增大,土壤容重逐渐降低;湿地群落的优势植物种群由朝天委陵菜转为黑麦草;朝天委陵菜间隔子长度和直径增大,分株数减小;间隔子长度、直径与分枝强度均呈显著负相关关系(P<0.05)。沼泽湿地恢复演替过程中,朝天委陵菜由选择垄断区域资源转向逃避或忍耐不利生境,体现了湿地克隆植物在异质性生境中独特的适应性。

Spacer characteristics and ramets influence the spatial distribution and resource acquisition of clonal plants.The relationship between the spacer characteristics and branching intensity might have a significant effect on ecological adaptations of clonal plants.The objective of this study was to examine the relationship between spacer characteristics and ramets of Potentilla supina under the different restorative succession periods.The study site was located in Yongchang Beihaizi National Wetland Park,Gansu Province,China.Survey and sampling were carried out in nine plots which were set up along the restorative succession periods of the plots,plotⅠ(5a),plotⅡ(15a),and plotⅢ(25a).Community traits were investigated and 30 clone sequences of P.supina were collected randomly at each plot.Spacer diameter,spacer length,branching intensity of P.supina was measured in the laboratory,and biomass of different organs was measured after being oven⁃dried at 85℃.The soil physical and chemical properties of three gradients were investigated.The result showed that in the process of restoration and succession of a marsh wetland,the plant height,ortet aboveground biomass,spacer length and diameter displayed increasing trend,while the coverage and branching intensity took on decreasing trend.There were significant negative correlation(P<0.05)between branching intensity and spacer length,and spacer diameter.In the process of restoration and succession on marsh wetlands,in initial stages,P.supina plants use the growth tactics of region resource monopoly,in later stages and endurance,or escape from poor habitat are used.This reflects the unique strategy of survival and reproduction of wetland clonal plants in heterogeneous habitats.