Data from: Vertical partitioning between sister species of Rhizopogon fungi on mesic and xeric sites in an interior Douglas-fir forest

Understanding ectomycorrhizal fungal (EMF) community structure is limited by a lack of taxonomic resolution and autecological information. Rhizopogon vesiculosus and R. vinicolor (Basidiomycota) are morphologically and genetically related species. They are dominant members of interior Douglas-fir (Pseudotsuga menziesii var. glauca) EMF communities, but mechanisms leading to their coexistence are unknown. We investigated the microsite associations and foraging strategy of individual R. vesiculosus and R. vinicolor genets. Mycelia spatial patterns, pervasiveness and root colonization patterns of fungal genets were compared between Rhizopogon species and between xeric and mesic soil moisture regimes. Rhizopogon spp. mycelia were systematically excavated from the soil and identified using microsatellite DNA markers. Rhizopogon vesiculosus mycelia occurred at greater depth, were more spatially pervasive, and colonized more tree roots than R. vinicolor mycelia. Both species were frequently encountered in organic layers and between the interface of organic and mineral horizons. They were particularly abundant within microsites associated with soil moisture retention. The occurrence of R. vesiculosus shifted in the presence of R. vinicolor towards mineral soil horizons, where R. vinicolor was mostly absent. This suggests that competition and foraging strategy may contribute towards the vertical partitioning observed between these species. R. vesiculosus and R. vinicolor mycelia systems occurred at greater mean depths and were more pervasive in mesic plots compared to xeric plots. The spatial continuity and number of trees colonized by genets of each species did not significantly differ between soil moisture regimes.外生菌根真菌（ectomycorrhizal fungal, EMF）群落结构的认知长期受制于分类分辨率不足与个体生态学信息的匮乏。泡囊根须腹菌（*Rhizopogon vesiculosus*）与酒红根须腹菌（*R. vinicolor*，担子菌门Basidiomycota）为形态与遗传上亲缘关系密切的物种，二者均为内陆花旗松（*Pseudotsuga menziesii* var. *glauca*）外生菌根真菌群落的优势类群，但二者共存的潜在机制至今尚不明确。本研究针对两种根须腹菌的无性系个体，对其微生境关联与觅食策略展开了探究。研究者对比了不同根须腹菌物种间，以及干旱、湿润两种土壤水分制度下，真菌无性系的菌丝空间分布格局、蔓延广度与根系定殖模式。研究人员通过系统性挖掘土壤样本，并借助微卫星DNA标记（microsatellite DNA markers）对根须腹菌属菌丝进行物种鉴定。相较于*R. vinicolor*的菌丝，*R. vesiculosus*的菌丝分布深度更深、空间蔓延范围更广，且定殖的林木根系数量更多。两种真菌的菌丝均常见于有机土层以及有机层与矿质土层的交界面处，且在保水性较强的微生境中丰度尤高。当*R. vinicolor*存在时，*R. vesiculosus*的分布会向矿质土层偏移，而此时*R. vinicolor*则极少出现在矿质土层中。这一结果表明，种间竞争与觅食策略差异，或是导致二者出现垂直生态位分化的关键因素。相较于干旱样地，湿润样地中的*R. vesiculosus*与*R. vinicolor*菌丝体平均分布深度更深，且蔓延范围更广。两种真菌无性系的空间连续性以及其定殖的林木数量，在不同土壤水分制度下均无显著差异。