The use of air bricks for planting roadside vegetation: A new technique to improve landscaping of steep roadsides in China's Hubei Province

Road construction is an important cause of environmental degradation, particularly in mountainous regions. However, re-establishing vegetation cover at the construction site can mitigate these problems, particularly on steep roadside slopes. In the present study, we developed two new planting techniques to increase vegetation cover on these slopes, in which planters fill the holes in air bricks (i.e., bricks with large holes that pass through the full depth of the brick) with soil, then plant grass or herbaceous species in the soil. Two variants of this technique (one in which the air bricks form a stairstep pattern, and another in which they form a smooth slope) were tested in an area with a warm climate near Shennongjia (Hubei Province) between 2006 and 2008. The new planting techniques promoted root growth, the development of a continuous vegetation cover, and the production of merchantable seeds compared with the conventional planting technique. This suggests that the air brick technique is more suitable for the study area, where the natural soils are thin, and may prove suitable for similar areas elsewhere in the world. The provisional results, based on 2 years of research, suggest that the new techniques represent a potentially valuable alternative for vegetation restoration, landscape conservation, and road maintenance/management in mountainous zones during and after highway construction. The techniques have strong potential for use in other areas. In addition, they provide a good example of using ecological engineering to increase vegetation cover on steep roadside slopes.