摘要
在生长季研究不同放牧率对草原牧草再生性能和地上净初级生产力的影响。结果表明，随着放牧率的增大，地上现存量呈线性下降，但地上净初级生产力（地上现存量＋家畜采食量）以2．67只羊／hm2处理最大，即存在超补偿性生长。地上最大现存量和最大净初级生产力出现的日期随着放牧率的增大有提前的趋势，二者随着放牧年限的延长均有较大幅度的下降。但降水可以缓和或加剧此变化的趋势。在冷蒿小禾草退化草原上，1．33和2．67只羊／hm2始牧时期为5月中下旬为宜，而重度放牧宜在6月上、中旬；重牧或过度放牧可降低牧草早期的再生能力，但可加快后期的再生速度，即后期牧草补偿性生长较明显。
The experiment was conducted in the Inner Mongolia steppe are located at 43°26'～44°08'N, 116°04'～ 117°05'E from 1990 to 1997. The stocking rates were 1. 33, 2. 67, 4. 00, 5. 33 and 6. 67 sheep/ha(or 1. 33,2. 00, 2. 67,3. 33 and 4. 00 in 1990)with Inner Mongolia fine wool sheep. There were 3 ha rota-tional paddocks per treatment with 45 or 46 days of grazing circle and 30 days of grazing intervals.The results showed that the heavy grazing resulted in faster herbage regrowth during autumn. Theaboveground present bioma5s(APB)decreased linerly with increase of stocking rates,but the abovegroundnet primary production(ANPP) (APB+intake of sheep)did not decreased linerly with increase of stockingrates,it mean the compensation or overcompensation exsited for ANPP. The stocking rate of 2. 67 sheep/ha may be the optimum for maximum of ANPP during growth season.
出处
《草地学报》
CAS
CSCD
1998年第4期275-281,共7页
Acta Agrestia Sinica
基金
国家科委"九五"攻关项目
国家自然科学基金!49790020
关键词
内蒙古
草原
放牧率
牧草再生
初级生产力
Inner Mongolia steppe
Stocking rates
Herbage regrowth
Aboveground net primary production
