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秦岭北坡1300米以下的山麓和低山地带,主要由一些次级岭脊组成,岭脊多与水系平行排列,顶部浑园柔和,形成很多由南向北的沟峪和长梁地形,一般山势低矮,起伏不大。气候属华北暖温带半湿润气候,气温自西向东逐渐增高,全年平均温度西部约13℃,中段在13.3℃左右。西部由于冷气流的侵袭,造成冷锋雨,因而降水自西向东递减。西部年降雨量在700毫米左右,东部650毫米左右。该地带的植被特点,就是在这种自然条件的综合作用下形成的。在拙著“秦岭北麓侧柏林的主要类型及地带性问题”一文(见《陕西林业科技》1978年第5期)中曾述及,第三纪晚期栎类已在秦岭北麓和山前盆地的阔叶林中出现。
The foothills and low mountains below 1,300 meters on the north slope of the Qinling Mountains are mainly composed of a number of secondary ridgelines. The ridgelines are arranged in parallel with the water system. The top of the hilltops are soft and form many gully valleys and long beam topographies from south to north. Low mountain, undulating. The climate belongs to warm temperate semi-humid climate in North China. The temperature gradually increases from west to east. The annual average temperature is about 13 ℃ in the west and about 13.3 ℃ in the middle. Due to the invasion of cold air currents in the west, cold front rain was caused and precipitation decreased from west to east. The annual rainfall in the west is about 700 millimeters and about 650 millimeters east. The characteristics of vegetation in this zone are formed under the combined effect of this natural condition. In my essay, “Main Types and Zonal Problems of Pleiobolus at the North Foot of the Qinling Mountains” (see Shaanxi Forestry Science and Technology, No. 5, 1978), it was mentioned that the Late Quaternary oaks were found in the northern foot of the Qinling Mountains and in the piedmont basin The emergence of broad-leaved forest.