Rillig Matthias C, Allen Michael F, Klironomos John N, Chiariello Nona R, Field Christopher B
Department of Biology, Soil Ecology & Restoration Group, San Diego State University, San Diego, CA 92182, USA Fax: (619)594-5676; e-mail:
Department of Botany, University of Guelph, Guelph, ON, Canada N1G 2W1, , , , , , CA.
Oecologia. 1998 Jan;113(2):252-259. doi: 10.1007/s004420050376.
Five co-occurring plant species from an annual mediterranean grassland were grown in monoculture for 4 months in pots inside open-top chambers at the Jasper Ridge Biological Preserve (San Mateo County, California). The plants were exposed to elevated atmospheric CO and soil nutrient enrichment in a complete factorial experiment. The response of root-inhabiting non-mycorrhizal and arbuscular mycorrhizal fungi to the altered resource base depended strongly on the plant species. Elevated CO and fertilization altered the ratio of non-mycorrhizal to mycorrhizal fungal colonization for some plant species, but not for others. Percent root infection by non-mycorrhizal fungi increased by over 500% for Linanthus parviflorus in elevated CO, but decreased by over 80% for Bromus hordeaceus. By contrast, the mean percent infection by mycorrhizal fungi increased in response to elevated CO for all species, but significantly only for Avena barbata and B. hordeaceus. Percent infection by mycorrhizal fungi increased, decreased, or remained unchanged for different plant hosts in response to fertilization. There was evidence of a strong interaction between the two treatments for some plant species and non-mycorrhizal and mycorrhizal fungi. This study demonstrated plant species- and soil fertility-dependent shifts in below-ground plant resource allocation to different morpho-groups of fungal symbionts. This may have consequences for plant community responses to elevated CO in this California grassland ecosystem.
来自一年生地中海草原的五种共生植物物种在贾斯珀岭生物保护区（加利福尼亚州圣马特奥县）的开顶式生长室内的花盆中进行了4个月的单作种植。在一项完全析因实验中，这些植物暴露于大气CO浓度升高和土壤养分富集的环境中。根系中的非菌根真菌和丛枝菌根真菌对资源基础变化的反应在很大程度上取决于植物物种。大气CO浓度升高和施肥改变了某些植物物种而非其他植物物种的非菌根真菌与菌根真菌定殖的比例。在大气CO浓度升高的情况下，小花亚麻的非菌根真菌根系感染率增加了500%以上，但大麦草的感染率下降了80%以上。相比之下，所有物种的菌根真菌平均感染率都随着大气CO浓度升高而增加，但仅燕麦和大麦草的增加显著。菌根真菌的感染率在施肥后，因不同植物宿主而增加、减少或保持不变。有证据表明，对于某些植物物种以及非菌根真菌和菌根真菌而言，两种处理之间存在强烈的相互作用。这项研究表明，地下植物资源分配到不同形态类群的真菌共生体中存在植物物种和土壤肥力依赖性的变化。这可能会对加利福尼亚草原生态系统中植物群落对大气CO浓度升高的反应产生影响。
