Mycorrhizal and endophytic richness and colonization in Cedrela odorata L., in agroforestry systems and secondary forest from southeastern Costa Rica

The roots of different forest species show mixed colonization by arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSE). In temperate ecosystems, AMF colonization and community structure change according to plantation age, while colonization by DSE is apparently unaffected. However, in tropical ecosystems, little has been documented on the possible changes caused by plantation age on mycorrhizal fungal communities. We analyzed AMF and DSE colonization and described the glomerospore community structure associated with three agroforestry systems of different Cedrela odorata plantation ages (8, 13 and 17 years), in addition to a secondary forest, during the dry season in southeastern Costa Rica. We detected statistical differences in total colonization in the agroforestry systems with respect to the secondary forest (P < 0.05). Among the agroforestry systems, total colonization was higher in 8-year-old trees and DSE were only detected in agroforestry systems with higher colonization in 8-year-old trees. The abundance and richness of glomerospores were higher in the agroforestry systems than in the secondary forest, with greater richness in younger plantations. We isolated 39 morphospecies, 27 from the plantations and 17 from the secondary forest, with a greater representativeness of Acaulospora and Glomus. We also provide four new AMF reports for Costa Rica (Acaulospora laevis, A. excavata, A. spinosissima, and A. bireticulata).