西藏河谷地区人工种草的投入产出比较分析

Comparison of the benefits of conservation and forage planting grasslands in the river valley area of Tibet

分析了西藏河谷地区六种草地的经济投入、产出和生态系统服务价值,模拟了投入增加下村落草地利用结构的改变与经济、生态产出的响应。结果表明:草地恢复管理中,围栏草地成本最低,为67元/hm^2,是一年生人工刈割草地的0.9%。围栏等草地恢复管理的经济产出为772元/hm^2,其中补贴收入占14.6%,另85.4%来自打工收入;而多年生人工放牧和一年生人工刈割草地的经济产出为4250元/hm^2与13135元/hm^2。相比经济产出,不同草地管理方式下生态系统服务价值差距有限,最大仅为27%。草地投入增加下,天然放牧草地转变为围栏草地及一年生人工刈割草地,并最终保持约1∶1的面积比。合理配置围栏草地与一年生人工刈割草地,可以实现区域较大的经济收入增长和生态系统服务的保障。

The conservation and utilization of grasslands are the basis for the sustainable development of grasslands and animal husbandry in China;however, 90% of natural grassland has been degraded to different levels. Prohibiting the utilization of ecosystems is a common approach in ecological conservation, e.g., fencing grasslands. Meanwhile, artificial seeding of forage species has also proved to be effective for ecosystem restoration. There are limited studies on the integrated ecological and economic effects of grassland use change. In this study, the economic and ecological benefits of six grassland management strategies in the river valley area of Tibet were analyzed using three aspects: input, economic output, and ecosystem service values. The results showed that the cost of fencing grassland was the lowest at 67 yuan/ hm^2, which was 0.9% of the cost of annual planting of mown grassland. The economic benefits of conserving grassland were 772 yuan/ hm^2, of which the subsidy was 14.6% and wage income was 85.4%. The economic benefits of perennial planting of grazing grassland and annual planting of mown grassland were 4,250 and 13,135 yuan/ hm^2, respectively. The differences in ecosystem service values among the grassland management options were limited, and the maximum gap was 27%. Considering both economic and ecological benefits, the integrated benefits of natural grazing grassland were higher than those of fencing or plowing grassland, but lower than those of the other strategies. Input (yuan/ hm^2 ) increased as natural grazing grassland converted to fenced grassland and annual planting of mown grassland at the village level, and was highest at 50∶50 fenced grassland and annual planting of mown grassland. Optimizing the land allocated to fenced grassland and annual planting of mown grassland could simultaneously boost economic development and guarantee a supply of ecosystem services for the local region.