Understanding the dynamics of arbuscular mycorrhizal fungi (AMF) in response to land use change is important for the restoration of degraded forests. Here, we investigated the AMF community composition in the roots of Pterocarpus tinctorius sampled from agricultural and forest fallow soils rich in aluminum and iron. By sequencing the large subunit region of the rRNA gene, we identified a total of 30 operational taxonomic units (OTUs) in 33 root samples. These OTUs belonged to the genera Rhizophagus, Dominikia, Glomus, Sclerocystis, and Scutellospora. The majority of these OTUs did not closely match any known AMF species. We found that AMF species richness was significantly influenced by soil properties and overall tree density. Acidic soils with high levels of aluminum and iron had a low mean AMF species richness of 3.2. Indicator species analyses revealed several AMF OTUs associated with base saturation (4 OTUs), high aluminum (3 OTUs), and iron (2 OTUs). OTUs positively correlated with acidity (1 OTU), iron, and available phosphorus (2 OTUs) were assigned to the genus Rhizophagus, suggesting their tolerance to aluminum and iron. The results highlight the potential of leguminous trees in tropical dry forests as a reservoir of unknown AMF species. The baseline data obtained in this study opens new avenues for future studies, including the use of indigenous AMF-based biofertilizers to implement ecological revegetation strategies and improve land use.

了解丛枝菌根真菌（AMF）响应土地利用变化的动态对于恢复退化森林非常重要。在这里，我们调查了从富含铝和铁的农业和森林休耕土壤中取样的紫檀根部的 AMF 群落组成。通过对 rRNA 基因的大亚基区域进行测序，我们在 33 个根样本中总共鉴定出了 30 个操作分类单元 (OTU)。这些 OTU 属于Rhizophagus、Dominikia、Glomus、Sclerocystis和Scutellospora属。这些 OTU 中的大多数与任何已知的 AMF 物种都不密切匹配。我们发现 AMF 物种丰富度受到土壤性质和整体树木密度的显着影响。铝和铁含量较高的酸性土壤的平均 AMF 物种丰富度较低，为 3.2。指示物种分析揭示了几个与碱饱和度（4 个 OTU）、高铝（3 个 OTU）和铁（2 个 OTU）相关的 AMF OTU。与酸度（1个OTU）、铁和有效磷（2个OTU）呈正相关的OTU被分配给Rhizophagus属，表明它们对铝和铁的耐受性。研究结果凸显了热带干燥森林中豆科树木作为未知 AMF 物种储存库的潜力。本研究获得的基线数据为未来的研究开辟了新的途径，包括使用本土的 AMF 生物肥料来实施生态植被恢复战略和改善土地利用。