In order to find the wetland vegetable niche pattern in semiarid grassland region

vegetation growth in wet zone

interlaced zone and drought zone of Siertan wet land

Yanchi County in Ningxia Hui Autonomous Region was studied with transect lines.The importance value

niche breadth and niche overlapping were measured by means of importance value

Levins niche breadth and Pianka niche overlapping indexes.The results showed that

saline tolerance of Kalidium foliatum was absolutely dominant in wet zone with the important value and niche breadth far greater than other species.Because the saline and alkaline of wet zone was too high

only a few species could survive.The importance value and niche breadth of A neurol epidium dasystachys was the largest in interlaced zone and drought zone.Compared with interlaced zone

niche breadth of most species was improved in drought zone

suggesting that drought zone was more suitable for plant existence.There was not a direct linear relationship betw een niche breadth and niche over lapping based on niche over lapping results of there zones.