【摘要】 土质道路水土流失是所有人工生态系统中最严重的土地利用类型,土壤侵蚀模数是相同条件下林地的250倍,农村道路修筑破坏了区域生态景观的完整性,为景观生态修复理论与技术研究提供了重要的实验场地。广大山区农村田间地块道路在种植和收获季节以外长期处于闲置状态,这为植物的种植和生长提供了可能。1997～2001年,以中国黄土丘陵区陕西省延安市小砭沟小流域农田道路为背景,以防止和减轻路面汇流引发的水土流失对道路的破坏和修复农村道路景观生态系统为目的,采用小区径流监测、施工统计和定点观测的方法,在路面进行了为期5a的种草实验。研究结果显示,农田作业道路路面不仅可以种草,而且具有一定生态经济价值,在条播下,胡枝子、小冠花、无芒雀麦每km年产值可达1068.88～3150.27元;同时,路面牧草可承受适度的通行压力,禾本科牧草一般可承受300t·次/a以下车辆碾压;道路种植禾本科牧草后,除有机质外,土壤中其它营养成份均有不同程度的亏损,因此有必要补充各种肥料延长路面牧草使用年限和提高牧草防蚀能力;路面种草后径流量减少46.15%～69.30%,土壤侵蚀量减少54.53%～77.80%,建设成本仅为石子路的27.69%～35.99%,维护费用仅为土质道路的30.52%,是一种经济可行的技术途径。道路种草后,路面雨季泥泞、旱季尘土飞扬的劣质景观被蜿蜒的绿色道路景观所取代,形似镶嵌在绵延山谷中的绿飘带,这无论在理论还是技术方面都是生态修复学和景观生态学研究的重要方向之一。更多还原

【Abstract】 In China and other countries of the world, terrene roads (unpaved or unsurfaced roads) are common in rural areas. Low design standards, however, may contribute to problems of soil and water erosion. As a result, erosion from terrene roads is often severe. Maintenance and construction of traffic roads are significant costs for modern societies. In many developing countries, especially in hilly rural areas, it is difficult to afford the high costs of surfaced roads such as stone or tar roads. And stone or tar roads often are not compatible with the demands of a “near-natural” landscape. Terrene (unpaved or unsurfaced) roads prevail in rural regions. In China there are more than three million kilometers which is about 80% of rural roads. So, is there an economic and ecological type of road construction and maintenance technology? To answer this question, we put a 7-year test (1997~2003) in Xiabiangou of Yan’an city, Shaanxi, P. R. China. Grasses were planted on terrene roads (‘botanic roads’) using criteria of soil and water conservation. The results showed that planting grass on terrene roads has economic and ecological benefits for the Loess Plateau. Construction costs of ‘botanic roads’ are 11.17% of stone road, and the costs of maintenance are 30.52% of non-grass terrene road.The test results showed that: the germination ratio of all kind of grasses was more than 82%. All kind of grasses except Lolium perenne L. had good adaptability to the environment and survived in winter. Ggrasses had better performance than legumes. On the road with less traffic there was also good production of seed or raw grass. The economic value of planting Bromus inermis Leyss. can be 2584.24 to 3150.27 RMB/km per year, and Lespedeza bicolor Turcz. is 1068.88~1194.04 RMB/km per year. In the sinking land, planting Coronilla varia L. can yield 2866.15 RMB/km per year. Botanic roads improve the aesthetics of the landscape. Instead of the mud and dust, they appear as a “green belt” dancing in the hilly area.Runoff of test road surfaces are decreased by 46.15%~69.30% and the soil erosion modulus decreased by 54.53%~77.80%. Our results showed that strip sowing was the best grass sowing method, and the first-choice varieties of grasses are Agropyron cristatum L.Gaertn, Bromus inermis Leyss., Lespedeza bicolor Turcz., and Coronilla varia L.Grasses can bear traffic under 300 tone.time/year. Agropyron cristatum L.Gaertn. had the best resistance to trampling; the second best was Bromus inermis Leyss. Legumes grass’s resistance to trampling was not as good as grasses. With traffic more than 300 tone.time/year, the place directly trampled by vehicles all died. There is 54.2 cm width bare wheel-print on the roads. The normal nutrient content, except soil organic matter, decreased in different degree on the road planted to grasses. After 5 years, the content of total nitrogen, phosphorus, potassium and active nitrogen, phosphorus, potassium had decreased 21.53%, 25.09%, 5.65%, 12.17% and 17.42% respectively. The ’botanic road’ therefore needs man-made fertilizer to compensate for the decline of soil nutrients.更多还原