陕西秦巴山区垂直自然带的土地演替

以陕西秦巴山区为案例，对土地演替的内涵、研究内容和演替历史做了论述，运用遥感技术编制土地类型图，运用计算机手段对秦岭南、北坡和大巴山北坡的不同垂直带层的土地演替做了模拟．认为土地演替是土地内部物流与能流转化迁移的结果，土地演替分为自然演替和人为演替两种过程．

LAND SUCCESSION ON THE VERTICAL NATURAL ZONES OF QINLING-BASHAN MOUNTATINOUS AREA IN SHAANXI PROVINCE

Land succession is one the advanced theorier in land research. Based on the map of land types made by application of remote sensing information,the in tension and resarch contents of land succession are discuss and the land succnession history of Qinghai-Bashan mountainous area in Shaanxi Province is analysed. After classifying lanel types,the main representative land types are selected and then: mitate the land succession patterns of different vertical zones on the northern and southern slope of Qinling Mountains and the northern slope of Bashan Mountains are imitated by computer. It conclueles that land succession is a selg-organigation process of land structure and function and is also the results of matter removing and energy transforming within land,which is sustained by certain geographical proceees. According to the source of its action power,land succession can be divided into 2 sorts: natural succession process and artificial succession process.Natural succession is a selg-adjusting,selg-sustaining and selg-developing process,usually expressing as an irreversible and gradual process with slow successive velocity and over a long timespan. Oh the contrary,artificisl succession process refers to that human economic acitivity participates in the exchange of matter and energy of land system,acceleratins of delaying the natural succession process. This kind of succession can usually be divided into 2 types: positive direction and converse direction successions. It evolves guite rapidly with shorter successive series. Moreover,artificial succession varies with differing natural conditions,especially with productivity level and human history in any specific area.