摘要：To test global change effects on lentic ecosystems, we examined I) if algae phenolic content was influenced by CO 2 treatments, and 2) if algivores fed CO 2 -treated algae were impacted. Four common Chlorophytes (Cladophora glomerata, Spirogyra grevilleana, Ulothrix, fimbriata, and Zygnema sp.) were grown under three atmospheric carbon dioxide environments (200, 360, and 3000 mg/L). Algivore (the microcaddisfly Hydroptila waubesiana [Trichoptera: Hydroptilidae]) feeding assays, using identically treated algae (C. glomarata and U. fimbriata) as a food source, were run in parallel. Generally, Folin-Denis reactive phenolics were highest among algae grown under high CO 2 treatments, intermediate at ambient CO 2 , and lowest under low CO 2 treatment. Differential species responses in reactive phenolics were observed, with U. fimbriata being most responsive (∼6 %) to CO 2 enrichment, and C. glomarata being unresponsive (<1%). Regardless of algal species or CO 2 treatment, developmental rates of H. wauhesiana larvae to mid and late instars were statistically identical. Percent survival for larvae given U. fimbriata and C. glomerata were similar; however, survival rates were higher when larvae were fed low CO 2 treated U. fimbriata. For larvae fed C. glomerata, the general trend was that larvae fed algae grown at high CO 2 levels had the greatest head capsule width; those fed algae at low CO 2 levels had the greatest head capsule length and pronotal length. In contrast, larvae fed U. fimbriata had the largest head capsule widths under ambient CO 2 levels, the largest head capsule widths under high levels, and had equal pronotal lengths at all CO 2 levels. Larvae fed C. glomerata grown under ambient conditions produced portable cases of the greatest length at the experiment's conclusion, but no distinct trend was seen for larvae fed U. fimbriata. Overall, CO 2 induced production of reactive phenolics in chlorophytes did not appreciably influence herbivorous microcaddisfly development or survival.
