典型草原亚洲小车蝗危害对植物补偿生长的作用

Impacts of damage caused by Oedaleus asiaticus on the compensatory growth of plants in steppe

以内蒙古典型草原亚洲小车蝗Oedaleus asiaticus为对象,通过田间罩笼和人工模拟取食2种方式,比较了亚洲小车蝗4个龄期及3种密度下对典型草原不同植物补偿性生长反应的特点。结果表明,3龄、4龄期罩笼试验地上生物量高于模拟取食(P<0.05),5龄、成虫罩笼试验地上生物量显著低于模拟取食试验(P<0.05),说明亚洲小车蝗的取食对植物生长存在明显的补偿生长作用。5龄亚洲小车蝗密度小于16头/m2时,地上生物量与对照间差异不显著(P>0.05),植物表现等补偿生长;成虫亚洲小车蝗密度大于4头/m2时,地上生物量显著低于对照区(P<0.05),植物表现欠补偿生长;3龄、4龄亚洲小车蝗密度大于4头/m2时,地上生物量显著高于对照区(P<0.05),植物表现超补偿生长。亚洲小车蝗3、4龄期,羊草Ley-mus chinensis和冷蒿Artemisia frigida出现超补偿生长,其他植物种群均出现等补偿生长;5龄和成虫期随密度增加,均出现欠补偿生长。

The compensatory growth of plant caused by grasshoppers,Oedaleus asiaticus,a common species in Inner Mongolian Steppe,was studied by using the field caging and artificial simulation methods and 4 different instrars of grasshoppers（3 instar,4 instar,5 instar and adults）,and 3 different densities（4,16 and 32 heads/m^2）.The results showed that the aboveground biomass of plant in the field trail was higher（P〈0.05） than that of the artificial simulated trail for O.asiaticus in 3 instrar and 4 instar.However,it was lower（P〈0.05） than that of the artificial simulated trail for O.asiaticus in 5 instar and adults.This suggested that the intake of O.asiaticus performed an obvious compensation growth of plant.There was no significant difference（P〉0.05） on the aboveground biomass in 5 instar while the density was below 16 heads/m^2,which was under equal compensatory growth of plant.When the density of adult grasshoppers was over 4 heads/m^2,the aboveground biomass of plant was lower（P〈0.05） than that of the control,which was under-compensatory growth of plant.When the density was over 4 heads/m^2 in 3 and 4 instar,the aboveground biomass of plant was higher（P〈0.05） than control,which was under over compensatory growth of plant.In 3 and 4 instar,Leymus chinensis and Artemisia frigida shown over compensatory growth,and the other plants shown equal compensatory growth.However,all plants shown under compensatory growth in 5 instar and adult with the increasing density.