Influence of enclosure onGlyeyrrhiza uralensiscommunity and distribution pattern in arid and semi-arid areas

Abstract

With the policies of conversion of cropland to forest and grassland and exclosure under no grazing carried on, the desert stppe ecosystems is under restoration and regeneration to some extent. However, long鄄term exclosure did not assure the restoration of plant communities in desert steppe. As was concerned, Glyeyrrhiza uralensis community tended to degrade. Taking the Glyeyrrhiza uralensis community under exclosrue of different ages after excavation as a subject, the influence of enclosure on Glyeyrrhiza uralensis population community and distribution pattern was discussed, by the method of the mean variance ratio and indices of aggregation intensity. The result showed:1) Under enclosure along with the increasing ages, species richness index and diversity index of Glyeyrrhiza uralensis community tended to increase. Evenness index firstly increased and then decreased. 2) The spatial pattern of Glyeyrrhiza uralensis, Agropyron cristatum, Artemisia sieversiana and Artemisia scoparia population were all changed. That of Glyeyrrhiza uralensis population and Agropyron cristatum population changed from random into aggregation, but the intercompetition was opposite. That of Artemisia sieversiana and Artemisia scoparia population changed from aggregation into random. 3) In arid and semi鄄arid region, the recovery of Glyeyrrhiza uralensis species needed 5 years, and the grass yield and the ground biological indexes are better. At that time, Glyeyrrhiza uralensis should be reasonably excavated, thus beneficial for the improvement of population development and related productivity.

Sustainable Utilization of Traditional Chinese Medicine Resources: Systematic Evaluation on Different Production Modes

“…As the extension of fostering time, herbal population density, medicinal ingredients, and biomass gradually increase. However, natural fostering may cause the degradation of competitiveness in licorice population after 5 years [28]. For some herbs, the shorter the growing years, the higher the content of the active ingredient such as calycosin glucoside and formononetin in Astragalus membranaceus [29].…”