Fransson Petra M A, Taylor Andrew F S, Finlay Roger D
Department of Forest Mycology and Pathology, SLU, Box 7026, S-75007 Uppsala, Sweden.
New Phytol. 2001 Dec;152(3):431-442. doi: 10.1046/j.0028-646X.2001.00276.x.
• Changes in below-ground ectomycorrhizal (ECM) community structure in response to elevated CO and balanced nutrient addition were investigated in a 37-yr-old Picea abies forest. • Trees in whole-tree chambers were exposed to factorial combinations of ambient/elevated CO (700 ppm) and fertilization (+/-). ECM fungal community structure was determined in 1997 and 2000 using a combination of morphotyping and molecular analyses. Samples were taken both from chambers and from reference trees receiving the same fertilization treatments but without chambers. • Significant effects on ECM community structure were found in response to elevated CO . Neither elevated CO nor fertilization altered species richness; however, there was considerable variation among samples, which may have masked treatment effects on individual species. After 3 yr, the effects of elevated CO on community composition were of the same magnitude as those seen after 15 yr of fertilization treatment. • Our results show that increasing atmospheric CO concentrations affect the community structure of root symbionts colonizing forest trees. The potential effects of altered ECM community structure on allocation and turnover of carbon and nutrients within forest ecosystems are discussed.
• 在一片37年生的欧洲云杉林中，研究了地下外生菌根（ECM）群落结构对二氧化碳浓度升高和养分均衡添加的响应。• 整树生长箱中的树木接受了环境/升高的二氧化碳（700 ppm）和施肥（+/-）的析因组合处理。1997年和2000年，结合形态分型和分子分析确定了ECM真菌群落结构。样本既取自生长箱，也取自接受相同施肥处理但没有生长箱的对照树。• 发现二氧化碳浓度升高对ECM群落结构有显著影响。二氧化碳浓度升高和施肥均未改变物种丰富度；然而，样本之间存在相当大的差异，这可能掩盖了处理对单个物种的影响。3年后，二氧化碳浓度升高对群落组成的影响与施肥处理15年后的影响程度相同。• 我们的结果表明，大气二氧化碳浓度升高会影响定殖在森林树木上的根系共生体的群落结构。文中还讨论了ECM群落结构改变对森林生态系统内碳和养分分配及周转的潜在影响。
