Foliar anatomical structures and ecological adaptabilities of dominant artemisia species of early sere of succession on arable old land after being abandoned in Loess Hilly Region
YANG Chao, LIANG Zong-Suo The College of Life Science of Sci-Tech A&F University, Yangling 712100, China
Artemisia species are dominant in early succession of abandonned farm lands in hilly regions of Loess. The faliar anatomy of three Artemisia species belonging to different seral stages was examined. Results showed mesophyll tissue structure differentiation from total-palisade to ring-palisade transitional forms in species of advancing seral stages, illustrating how the adaptability of Artemisia species to dry environments decreases as succession proceeds. In addition, the Artemisia species presented tight alignment of mesophyll cells and anomalous shapes of epidermal-cells. The leaf surface of all three species had the tentacle and epidermal fur structures often found in drought-tolerant plants. In A. scoparia and A. giraldii, a special air cavity was found in the leaves. The Artemisia species examined are well adapted to dry areas through both anatomical and ecological strategies explaining their important role as the pioneer indigenous plants in the seral succession of Loess hills.