恢复生态学在“黑土型”退化草地植被改建中的应用

Application of restoration ecology in ‘black soil type’ degraded grassland rebuilding

通过对三江源区“黑土型”退化草地发生现状、成因的调查研究与分析,以恢复生态学理论为依据,提出了“黑土型”退化草地恢复理论.研究结果认为,对青藏高原高寒草甸退化草地生态系统的恢复与改建,可根据退化草地的等级(系统受损程度)采取相应的恢复措施,中度和轻度退化草地改良通过休牧、灭鼠、毒杂草防除等措施即可达到其植被的自然恢复.重度和极度退化草地由于原生植被及生草层遭到了严重破坏,出现了大面积的次生裸地,植被的自然恢复能力已基本丧失,只有通过利用适宜草种改建人工和半人工草地,才能快速恢复其退化草地植被.利用禾本科适宜牧草在高寒草甸重度和极度退化草地上改建的人工和半人工草地,其植被的盖度基本上接近于原生植被,而显著高于退化草地的植被盖度;改建植被的地上总生物量是未退化植被的4-5倍,是退化草地的10-15倍.选择适宜的草种是“黑土滩”植被改建成功的关键,施肥、灭杂、灭鼠以及适度放牧利用等人工调控措施是人工和半人工草地持续利用的关键,人工调控可有效维持人工草地的生产力,防止其快速衰退.

In view of the present situation of the serious degradation alpine meadow- ‘ black soil type’ degraded grassland in the source region of Yangtze River,Yellow River and Lantsang River,through years of field investigation and studies, and using the principles of restoration ecology, the authors proposed the alpine meadow degradation ecosystem restoration and reconstruction pattern in the source region of three rivers. According to the pilot studies, for medium, light degraded grasslands, they are minor-damaged degraded grassland ecosystem. The damage to the system is not overload and reversible. Reducing grazing pressure and rat damage in several years, it would revert to the initial state. However, for heavy degraded grassland and extreme （‘ black soil type’） degraded grassland, the native vegetation Kobresia humilis meadow in the grassland vegetation has almost disappeared,the capacity of natural breeding and update is too low, therefore it is difficult to return to the initial state through enclosed in short term,only through reconstruction and renovation,its vegetation could be restored. Using the native grasses seed to renovation artificial grassland in the＇ black soil type＇ degraded pasture, it can not only achieve the goal of restoring grassland vegetation（grass production increased 4-5 times than normal meadow, and 10- 15 times than degraded meadows）, but also meet the needs of local livestock production. It is the key to success of planting artificial grassland in the ‘black soil type’ degraded pasture to choose suitable grass seed and agronomic measures. Artificial control is also an important factor for maintaining high productivity for artificial grassland rebuilding in ‘black soil type’ degraded grassland.