Anderson R C, Liberta A E, Dickman L A
Department of Biological Sciences, Illinois State University, 61761, Normal, Illinois, USA.
Oecologia. 1984 Sep;64(1):111-117. doi: 10.1007/BF00377552.
Abundance and distribution of vascular plants and vesicular-arbuscular mycorrhizal (VAM) fungi across a soil moisture-nutrient gradient were studied at a single site. Vegetation on the site varied from a dry mesic paririe dominated by little bluestem (Schizachyrium scoparium) to emergent aquatic vegetation dominated by cattail (Typha latifolia) and water smartweed (Polygonum hydropiperoides). Plant cover, VAM spore abundance, plant species richness, and number of VAM fungi represented as spores, had significant positive correlations with each other and with percent organic matter. The plant and VAM spore variables had significant negative correlations with soil pH and available Ca, Mg, P and gravimetric soil moisture. Using stepwise multiple regression, Ca was found to be the best predictor of spore abundance. Test for association between plant species and VAM fungal spores indicated that the spores of Glomus caledonium are associated with plants from dry, nutrient poor sites and spores of gigaspora gigantea are positively associated with plants occurring on the wet, relatively nutrient rich sites. Glomus fasciculatum was the most abundant and widely distributed VAM fungus and it had more positive associations with endophyte hosts than the other VAM fungi. We found no relationship between beta niche breadth of plant species and the presence or absence of mycorrhizal infection. However, our data suggest that some plant species may vary with respect to their infection status depending upon soil moisture conditions that may fluctuate seasonally or annually to favor or hinder VAM associations.
在一个单一地点，研究了维管植物和泡囊 - 丛枝菌根（VAM）真菌在土壤水分 - 养分梯度上的丰度和分布情况。该地点的植被从以小须芒草（Schizachyrium scoparium）为主的干旱中生草原，到以香蒲（Typha latifolia）和水蓼（Polygonum hydropiperoides）为主的挺水水生植被各不相同。植物覆盖度、VAM孢子丰度、植物物种丰富度以及以孢子表示的VAM真菌数量，彼此之间以及与有机质百分比均呈显著正相关。植物和VAM孢子变量与土壤pH值以及有效钙、镁、磷和重量法测定的土壤湿度呈显著负相关。通过逐步多元回归分析发现，钙是孢子丰度的最佳预测指标。植物物种与VAM真菌孢子之间的关联性测试表明，喀里多尼亚球囊霉（Glomus caledonium）的孢子与来自干旱、养分贫瘠地点的植物相关联，而大巨孢囊霉（Gigaspora gigantea）的孢子与生长在湿润、相对养分丰富地点的植物呈正相关。聚丛球囊霉（Glomus fasciculatum）是最丰富且分布最广的VAM真菌，与内生菌宿主的正相关关系比其他VAM真菌更多。我们发现植物物种的β生态位宽度与菌根感染的有无之间没有关系。然而，我们的数据表明，一些植物物种的感染状况可能会因土壤湿度条件的变化而有所不同，土壤湿度条件可能会随季节或年份波动，从而有利于或阻碍VAM共生关系。
