Using the Grey System Theory for analysis of relationship between Sabina vulgaris growth and ecological factors.

To study growth and influencing factors of Sabina vulgaris,habitat and growth conditions for re-gions of natural distribution in Inner Mongolia were surveyed,and the relationship between growth and eco-logical factors were analyzed with Grey System Theory.Results showed that(1) S.vulgaris could grow in arid and semiarid areas with an average annual temperature -5.0 °C,an extreme minimum temperature -43.0 °C,an extreme high temperature 38.6 °C,and an average annual rainfall 180 mm.Also,the average annual shoot growth was between 7.7 and 14.6 cm.(2) According to Grey System Theory,the order of factors affecting S.vulgaris growth were: ≥ 10 °C accumulated temperature annual precipitation extreme maximum temperature extreme minimum temperature annual evaporation altitude average annual temperature.So for afforestation through introduction and dissemination of S.vulgaris in arid areas,annual precipitation should be considered,but the heat factor should not be ignored,especially the ≥ 10 °C accumulated temperature.