松嫩平原旱地异质生境芦苇分株不同叶龄叶片光合色素含量可塑性及空间格局

By using the method of the whole ramets sampled at regular intervals and measured all leaves one by one, the plasticity and spatial patterns on photosynthetic pigment contents in each age class leaves of Phragmites australis ramets were researched in two heterogeneous dryland habitats in Songnen Plains of Northeast China at different periods. The results showed that differences on photosynthetic pigment contents of three types were generally higher in different age class leaves in H1 than in H2 between two habitats at different periods. The differences were synchronization on the contents of chlorophyll a, chlorophyll b and total chlorophyll, namely there were no significant differences between leaves of the older age class pairs in the under ramets and the younger age class pairs in the upper ramets, but there were significant differences between leaves of several age class pairs in the middle ramets; the differences of carotenoid contents increased and decreased sometimes. Although the photosynthetic pigment contents of the leaves were plasticity within and between habitats, they do have the same spatial patterns. In addition to the carotenoid contents of the leaves in H2 in August 15, changes on photosynthetic pigment contents of three types were all the quadratic curve with increasing of leaf age classes in two habitats at different periods. The important functional leaves of photosynthetic production were in the middle ramets in two habitats in Songnen Plains from July 15th to August 15th.