典型草原亚洲小车蝗危害对植物补偿生长的作用

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。

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

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/m2).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/m2,which was under equal compensatory growth of plant.When the density of adult grasshoppers was over 4 heads/m2,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/m2 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.