Hughes L, Bazzaz F A
Dept. of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA fax: (617) 495 9300 e-mail:
Oecologia. 1997 Jan;109(2):286-290. doi: 10.1007/s004420050085.
We measured the effect of elevated CO on populations of the western flower thrips, Frankliniella occidentalis and on the amount of leaf damage inflicted by the thrips to one of its host plants, the common milkweed, Asclepias syriaca. Plants grown at elevated CO had significantly greater aboveground biomass and C:N ratios, and significantly reduced percentage nitrogen. The number of thrips per plant was not affected by CO treatment, but the density of thrips (numbers per gram aboveground biomass), was significantly reduced at high CO. Consumption by thrips, expressed as the amount of damaged leaf area per capita, was significantly greater at high CO, and the amount of leaf area damaged by thrips was increased by 33%. However overall leaf area at elevated CO increased by 62%, more than compensating for the increase in thrips consumption. The net outcome was that plants at elevated CO had 3.6 times more undamaged leaf area available for photosynthesis than plants at ambient CO, even though they had only 1.6 times the overall amount of leaf area. This study highlights the need for measuring the effects of herbivory at the whole-plant level and also the importance of taking herbivory into account when predicting plant responses to elevated CO.
我们测定了高浓度二氧化碳对西花蓟马（Frankliniella occidentalis）种群数量的影响，以及蓟马对其寄主植物之一——普通马利筋（Asclepias syriaca）造成的叶片损伤量。在高浓度二氧化碳环境下生长的植物地上生物量和碳氮比显著更高，而氮含量百分比显著降低。每株植物上蓟马的数量不受二氧化碳处理的影响，但蓟马的密度（每克地上生物量中的数量）在高浓度二氧化碳环境下显著降低。以人均受损叶面积表示的蓟马取食量在高浓度二氧化碳环境下显著更大，蓟马造成的叶面积损伤量增加了33%。然而，高浓度二氧化碳环境下的总叶面积增加了62%，足以弥补蓟马取食量的增加。最终结果是，即使高浓度二氧化碳环境下植物的总叶面积仅为环境二氧化碳环境下植物的1.6倍，但可供光合作用的未受损叶面积却是后者的3.6倍。这项研究凸显了在整株植物水平上测定食草作用影响的必要性，以及在预测植物对高浓度二氧化碳的反应时考虑食草作用的重要性。
