Lawrence Beth, Fisk Melany C, Fahey Timothy J, Suárez Esteban R
Department of Natural Resources, Cornell University, Ithaca, NY 14853, USA.
New Phytol. 2003 Jan;157(1):145-153. doi: 10.1046/j.1469-8137.2003.00649.x.
• Exotic earthworms can modify or eliminate surface organic (Oe/Oa) horizons in cold-temperate forest ecosystems and have profound effects on the forest soil environment, especially the rooting zone. • We examined the effects of earthworm colonization of northern hardwood forest soils on the abundance and morphology of mycorrhizal fungi associated with sugar maple ( Acer saccharum ). We compared mycorrhizal associations of areas of earthworm invasion with those of reference (no-worm) areas in Arnot Forest, central New York, USA. • The organic horizon in reference areas had higher mycorrhizal colonization rates and higher colonized root length than did surface layers in areas with active earthworm populations. Hyphal coils were more abundant and also formed a greater proportion of total fungal colonization in reference plots. Vesicles were more abundant and were a higher contribution to total colonization in earthworm plots, indicating a possible stress response to the presence of earthworms. • By affecting mycorrhizal colonization and morphology, earthworms may influence nutrient uptake capacity of dominant forest species. Our results suggest that a profound change in the mycorrhizal system will be one component of the potential ecosystem effects of invasion of new forest habitat by nonnative earthworms.
• 外来蚯蚓可改变或消除寒温带森林生态系统中的表层有机（Oe/Oa）土层，对森林土壤环境，尤其是根系生长区产生深远影响。
• 我们研究了北方硬木森林土壤中蚯蚓定殖对与糖枫（Acer saccharum）相关的菌根真菌丰度和形态的影响。我们比较了美国纽约州中部阿诺特森林中蚯蚓入侵区域和对照（无蚯蚓）区域的菌根关联情况。
• 对照区域的有机土层比有活跃蚯蚓种群区域的表层具有更高的菌根定殖率和更长的定殖根长度。在对照样地中，菌丝线圈更丰富，在总真菌定殖中所占比例也更大。在蚯蚓样地中，泡囊更丰富，对总定殖的贡献更高，这表明可能是对蚯蚓存在的一种应激反应。
• 通过影响菌根定殖和形态，蚯蚓可能会影响优势森林物种的养分吸收能力。我们的结果表明，菌根系统的深刻变化将是外来蚯蚓入侵新森林栖息地潜在生态系统影响的一个组成部分。
