锡林郭勒典型草地适宜始牧期的选择

Selection of suitable grazing-beginning period for typical grassland in Xilingol

放牧时期的选择是决定能否在生态安全的前提下有效利用草地资源的重要条件。为明确始牧期对草地的影响,在锡林郭勒盟典型草地设置两种不同始牧期(5月10日、6月10日开始放牧)样地及不放牧对照样地(CK)。于2019年的6月、8月及10月测定各个样地的植被高度、盖度、地上生物量并计算草地牧草增长速率及理论载畜量。结果显示,在6月,不同始牧期草地植被的各项指标均无显著性差异(P<0.05)。8月至10月间,6月始牧草地的植被高度、盖度、地上生物量等各项指标显著高于5月始牧的草地(P<0.05)。同时,6至8月间6月始牧草地的牧草增长速率高于5月始牧草地,8至10月间不同始牧期草地的牧草增长速率基本持平。在载畜能力方面,6月始牧草地始终保持着更高的载畜能力。综合考虑草地高度、盖度、生产力、牧草增长速率及承载能力等各因素,6月中旬开始放牧较为合适。

The choice of grazing period is an important condition to determine whether the grassland can be effectively used under the premise of ecological security.In order to clarify the influence of the grazing-beginning period on the grassland productivity,two treatments of grazing-beginning date(May 10 th and June 10 th),compared with the no-grazing(CK),were set up in the typical grassland of Xilingol league.Indicators of grassland vegetation condition such as vegetation height,coverage and aboveground biomass were measured in June,August and October 2019,forage growth rate and theoretical livestock carrying capacity were calculated to estimate the utilization of grassland.The results showed that in June,there was no significant difference in grassland vegetation indicators in different grazing-beginning treatments.In August and October,vegetation height,coverage and aboveground biomass were significantly higher in the treatment of grazing-beginning in June than in grazing-beginning in May(P<0.05).Meanwhile,from June to August,the forage growth rate of grazing-beginning in June was higher than that of grazing-beginning in May.The growth rates from August to October in different grazing-beginning treatments were basically the same.Based on the forage available and livestock demanding balance analysis,grazing-beginning in June is more appropriate than grazing-beginning in May,considering factors such as grassland height,coverage,primary productivity,forage growth rate and carrying capacity.