毛乌素流动沙地飞播后沙丘的固定过程

Process of Moving Sand Dunes Stabilization AfterAerial Seeding in Maowusu Area

从飞播后影响沙丘固定的地貌因素以及不同沙丘类型区飞播后所能达到的固定水平和时间进程等方面，对毛乌素流动沙地飞播后沙丘的固定过程进行了研究。研究表明，在沙丘地貌要素中，飞播后影响沙丘固定的最关键因子是沙丘迎风坡坡度，其次为沙丘高度。当播区沙丘以单个新月形沙丘为主，沙丘普遍高度在５ｍ以下时，飞播植物可迅速占满整个播区，飞播后１０年内流沙可基本上得到全部固定。当播区沙丘形态以格状沙丘为主，沙丘高度在１０ｍ以上时，飞播后植物仅能在丘间地和沙丘下部定居，而且很难扩展其定居范围，这种沙丘类型区飞播后流沙不可能得到全部固定。

The geomorphic factors that influence dune stabilization as well as the levels andcourses of dune stabilization of different dune areas following aerial seeding in the Maownsusandyland were discussed.The studies shows that among the geomorpltic factors of dunes thekey one which has the most important influence on sand stabilization after seeding is the wind-ward slope of dunes,and second is dune height.In the seeding areas with dune height belowe 5meters and dune density belowe 0.6 and the crescent dunes as the dominant dune shape,thesaplings is well-distributed and the dunes can be totally fixed in 10 years after seeding.While inthe seeding areas with dune height over 10 meters and dune density over 0.8,and the checkdunes as donunant dune shape,the saplings can only colonize on the bottomlands and the lowerpart of dunes,and it is very hard for aerial seeding plants to expand their colonizing range due tothe harsh ensting conditions.the course of sand stabilization is quite slow,and it is impossible ofthis kind of dune area to be fixed by aerial seeding.