Soil biodiversity loss due to pollution may affect ecosystem services negatively. This environmental problem may be solved by phytoremediation, which is an effective strategy to manage and remediate contaminated areas. During this remediation process, the establishment of plant communities may improve soil fungal community structure and, in particular, may favour mycorrhizal symbiotic associations. As a consequence, afforestation of degraded lands will have different outcomes on fungal diversity and functionality, which will depend on the selected tree and shrub species.

We analysed soil fungal diversity and functional guilds by high-throughput sequencing of environmental DNA in a trace element contaminated area, part of a large scale phytoremediation project running for 20 years. We selected five habitats for comparison purposes: three under the canopy of selected tree species (wild olive, white poplar and stone pine), adjacent treeless areas (grassland) and non-remediated areas (bare soil).

Soil fungal diversity and richness seemed to be enhanced by phytoremediation. White poplar soil had the highest diversity and richness compared to wild olive and stone pine. Fungal communities were especially different between stone pine, with soils rich in organic C and high C:N ratio, and grassland soils.

We identified 9,428 fungal OTUs from which 1,283 were assigned to a unique functional guild; the most abundant belonging to saprotrophic, plant pathogenic and ectomycorrhizal functional guilds. Ectomycorrhizal fungi were more abundant in soils under ectomycorrhizal host trees. Saprotrophs were abundant in grassland and wild olive soils, while plant pathogens were abundant in non-remediated soils.

The remediation of soils (clean-up and amendment addition) allowed the natural establishment of grassland habitats throughout the study area, increasing fungal diversity, richness, taxonomy and functionality, when compared to non-remediated soils. Tree afforestation allowed the establishment of a forest type community bringing a further recruitment of fungal taxa, mainly the ectomycorrhizal fungal guild. Afforestation with different tree species showed species-specific effects on soil N, organic C, Ca and C:N ratio which led to increased spatial heterogeneity in areas with potential to recruit a wider diversity of fungi.

污染造成的土壤生物多样性丧失可能对生态系统服务产生负面影响。这种环境问题可以通过植物修复来解决，这是管理和修复受污染地区的有效策略。在此修复过程中，建立植物群落可能会改善土壤真菌群落结构，尤其可能会促进菌根共生协会。结果，退化土地的造林将对真菌的多样性和功能性产生不同的结果，这将取决于所选的树木和灌木物种。

我们通过对痕量元素污染区域中的环境DNA进行高通量测序，分析了土壤真菌的多样性和功能协会，这是一项为期20年的大规模植物修复项目的一部分。为了进行比较，我们选择了五个栖息地：在选定树种（野生橄榄，白杨树和石松）的树冠下，邻近的无树地区（草地）和非修复区（裸土）下的三个栖息地。

植物修复似乎增强了土壤真菌的多样性和丰富性。与野生橄榄和石松相比，白杨土壤具有最高的多样性和丰富性。富含有机碳和高C：N比的石松与草地土壤之间的真菌群落尤其不同。

我们确定了9,428个真菌OTU，其中1,283个被分配到一个独特的功能行会。最丰富的属于腐生性，植物病原性和外生菌根功能性协会。外生菌根宿主树下土壤中的外生菌根真菌更为丰富。在草地和野生橄榄土壤中，腐生菌丰富，而在未经修复的土壤中，植物病原体丰富。

与未修复的土壤相比，土壤的修复（清理和添加改良剂）可以在整个研究区域内自然建立草地栖息地，从而增加了真菌的多样性，丰富性，分类学和功能。植树造林允许建立森林型社区，从而进一步招募真菌类群，主要是外生菌根真菌协会。不同树种的造林对土壤氮，有机碳，钙和碳：氮的比例显示出特定于物种的影响，这导致具有吸收更多种类真菌潜力的地区的空间异质性增加。