Abstract:

In the majority of North Yinshan Mountains, the lowlying land in farmingpastoral interleaving areas has been reclaimed, due to the increase of population, grassland slope was reclaimed exhaustedly. Recently, many grassland slopes became arable lands. The ecological environment deterioration became more and more serious. Taking Saiwusu of Damao County and Baotou City of Inner Mongolia as example, this paper studied the effect of reclamation on erosion, vegetation and soil characteristics. The results indicated that severe wind erosion in spring and severe water erosion in summer eroded the soil of slopping fields; reclamation has brought remarkable changes in vegetation, annual herb such as Salsols collina, Corispermum declinatum, Chenopodum aristatum, Artimisia annua et al. grew vigorously, while perennial herb such as Stipa krylovii, Leymus chinensis and Agropyron cristatum were inhibited; soil fertility declined sharply, due to the erosion and harvest. In the first year after the grassland converted to slopping field soil erosion increased over 5 times, soil fertility droped 30%, and vegetation changed completely. After 4 years reclamation, soil fertility droped 50%, vegetation became sparse, crop yield was low, the slopping fields were no longer fit to continue farming, and large areas were abandoned. Due to sparse vegetation, low soil fertility and intense erosion, the abandoned slopping fields caused not only serious disturbances on the local ecological environment, but also became a dust storm source, thus brought serious threat to the ecological safety of Northern China. Therefore, protecting basic grassland, strictly controlling grassland reclamation is extremely imperative.

Key words: farmingpastoral interleaving area, grassland slope, vegetation, soil

摘要：

阴山北麓广大农牧交错区由于人口增加,草原低洼地已被开垦殆尽,近年来,草原上大量坡地被开垦为坡耕地。由此带来的生态恶化问题日益严重。以内蒙古包头市达茂旗腮吾素嘎查为例,研究了阴山北麓农牧交错区草原坡地开垦对土壤侵蚀、植被数量特征和土壤理化性质的影响。研究结果表明:①草原坡地开垦后,土壤侵蚀严重,春季以风蚀为主,夏季以水蚀为主；②草原坡地开垦造成植被发生明显变化,猪毛菜、刺藜、黄花蒿、绳虫实等一年生草本植物占据主导地位,而多年生优良牧草克氏针茅、羊草和冰草等相对较少；③草原坡地开垦使土壤肥力大幅下降,并且逐渐粗质化。草原坡地开垦第1年,土壤侵蚀量增加5倍以上,肥力下降30%,植物组成明显变化,开垦第4年,土壤肥力下降约50%,植被稀疏,此时已经不适合继续耕种,被大量摞荒。这些被摞荒的坡耕地由于植被稀疏,土壤贫瘠,水土流失剧烈,不仅对当地生态环境造成严重干扰,而且成为沙尘暴源地,给北方的生态安全带来严重威胁。因此,保护基本草原必须严控草原开垦。

关键词: 农牧交错区；草原坡地；植被；土壤