Department of Environmental Sciences and Technology, University of Maryland, College Park, MD 20742, USA.
J Med Entomol. 2013 May;50(3):521-32. doi: 10.1603/me12149.
Elevated atmospheric CO2 can alter aquatic communities via changes in allochthonous litter inputs. We tested effects of atmospheric CO2 on the invasive Aedes albopictus (Skuse) and native Aedes triseriatus (Say) (Diptera: Culicidae) via changes in competition for microbial food or resource inhibition/toxicity. Quercus alba L. litter was produced under elevated (879 ppm) and ambient (388 ppm) atmospheric CO2. Saplings grown at elevated CO2 produced greater litter biomass, which decayed faster and leached more tannins than saplings at ambient CO2. Competition was tested by raising larvae in different species and density combinations provisioned with elevated- or ambient-CO2 litter. Species-specific performance to water conditions was tested by providing single-species larval cohorts with increasing amounts of elevated- or ambient-CO2 litter, or increasing concentrations of tannic acid. Larval densities affected some fitness parameters of Ae. albopictus and Ae. triseriatus, but elevated-CO2 litter did not modify the effects of competition on population growth rates or any fitness parameters. Population growth rates and survival of each species generally were affected negatively by increasing amounts of both elevated- and ambient-CO2 litter from 0.252 to 2.016 g/liter, and tannic acid concentrations above 100 mg/liter were entirely lethal to both species. Aedes albopictus had consistently higher population growth rates than Ae. triseriatus. These results suggest that changes to litter production and chemistry from elevated CO2 are unlikely to affect the competitive outcome between Ae. albopictus and Ae. triseriatus, but that moderate increases in litter production increase population growth rates of both species until a threshold is exceeded that results in resource inhibition and toxicity.
大气中二氧化碳浓度升高可通过改变异源凋落物输入来改变水生群落。我们通过微生物食物竞争或资源抑制/毒性变化来测试大气 CO2 对入侵的白纹伊蚊（Skuse）和本地的三带喙库蚊（Say）（双翅目：库蚊科）的影响。在升高（879 ppm）和环境（388 ppm）大气 CO2 下生产白栎凋落物。在升高 CO2 下生长的树苗产生的凋落物生物量更大，比在环境 CO2 下生长的树苗分解更快，淋溶出更多的单宁。通过在不同物种和密度组合中饲养幼虫，并提供升高或环境 CO2 凋落物来测试竞争。通过向单一种群幼虫提供越来越多的升高或环境 CO2 凋落物，或升高单宁酸浓度来测试物种对水条件的特定表现。幼虫密度影响白纹伊蚊和三带喙库蚊的一些适合度参数，但升高 CO2 凋落物并未改变竞争对种群增长率或任何适合度参数的影响。随着从 0.252 到 2.016 g/L 的升高和环境 CO2 凋落物数量的增加，以及单宁酸浓度超过 100 mg/L，两种物种的种群增长率和存活率通常都会受到负面影响。与三带喙库蚊相比，白纹伊蚊的种群增长率始终较高。这些结果表明，大气 CO2 升高导致凋落物产生和化学性质的变化不太可能影响白纹伊蚊和三带喙库蚊之间的竞争结果，但适度增加凋落物产生会增加两种物种的种群增长率，直到超过导致资源抑制和毒性的阈值。
