Effect of Morphology and Physiology of Wetland Plants on Plateaus at Different Altitudes

The growth status, chlorophyll content,soluble sugar and free proline content,and superoxide dismutase(POD)activities in four species of common perennial wetland plants transplanted to different altitude levels on the Napahai plateau wetland,and the physiological characteristics of the plants during growth were studied.The results showed that the growth status of Scirpus validus,Heleocharis dulcis,Sparganium stoloniferum and Zizania latifolia were improved as altitude decreased.Plant heights of the four wetland plant species tended to increase as altitude decreased.Both S.validus and H.dulcis exhibited widening stem length as altitude decreased.The leaf widths of S.stoloniferum and Z.latifolia tended to increase as altitude decreased.The chlorophyll(a+b) contents of these wetland plants tended to decline as altitude decreased,as did soluble sugar and free proline content.POD activity in H.dulcis,S.stoloniferum and Z.latifolia decreased with decreasing altitude but showed no significant change in S.validus;POD activity in S.stoloniferum and Z.latifolia were much higher than the other two species.Therefore,the adaptive morphological and physiological characteristics of the four species to habitats at different altitudes had many approaches,such as variations in morphology,photosynthesis,metabolisms of cold-resisting substances and systems of anti-oxidative enzymes at different altitudes.The different adaptive approaches between the plants not only exhibited common rules,but also possessed their own characteristics.