Responses Of Rhizomatous Clonal Plants To Foliage Clipping In The Otindag Sandland, China

Excessive grazing is one of the important factors causing land desertification in the Otindag Sandland. Rhizomatous clonal grasses dominating the vegetation in this region are frequently exposed to grazing as well as disturbances of sand burial and nutrient deficiency. Through clonal growth, single genets of these clonal grasses can span heterogeneous/patchy habitats and are liable to partial/uneven grazing and sand burial. Clonal integration may act as one of the compensatory mechanisms for the regrowth of grazed clonal parts or ramets. Moreover, it may also alleviate the interactive effects of grazing and sand burial/nutrient stress. In this dissertation effects of clonal integration were examined in both field and pot experiments using the typical rhizomatous dune and/or grassland plant species in the Otindag Sandland.In a field experiment, individual plants of two rhizomatous clonal species (Bromus ircutensis Kom. and Psammochloa villosa (Trin.) Bor.) and two non-clonal ones (Artemisia intramongolica H.C.Fu and Astragalus melilotoides Pall.) were subjected to 0% (control), 50% and 90% of foliage clipping respectively. The results showed that relative growth rate (RGR) of Bromus and Psammochloa increased significantly under both 50% and 90% of foliage clipping, whereas that of Artemisia and Astragalus decreased under 90% of foliage clipping. After more than two months of growth, aboveground recovery of Artemisa and Astragalus was more incomplete than that of Bromus and Pammocholoa as compared to the control. These results...