陕北黄土高原臭柏群落进展演替和逆行演替

The Progressive and Regressive Succession of the Sabina Vnigaris Community in the LoessPlateau of Northern Shaanxi Province

认为臭柏群落进展演替是在活动基质（流沙）上开始，终止于固定基质，其实质是在臭柏群落作用下，基质物理和化学特征以及水条件向着有利于植物生活的方向发展。在逆行演替阶段，植物群落对基质作用微弱，水条件变劣，耐旱的微观植物群落起着主导作用。整个演替过程，是植物群落作用下土壤性的内因动态演替。

The progressive succession of the Sabina Vulgaris community begins on mobile substrate(mobile sand),it stops on the fixed substrate,the essence is developing physical and chemical proper ty and moisture of the substrate under the influence of Sabina vulgaris community, it is favourable forlife of the plant.In the stage of regressive succession the influence of the Sabina vulgaris communityis little on the substrate, edaphic humidity lessen, xerophytio micro-organism play a decisive role inplant community.The fundamental driving force of.the succession is generated from an edaphologicalendodynamic force under the reaction of plant communities in all process.