Changes in community structure of ectomycorrhizal fungi associated with Pinus montezumae across a volcanic soil chronosequence at Sierra Chichinautzin, Mexico

Abstract

Ectomycorrhizal (ECM) communities of Pinus montezumae Lamb. var. montezumae were studied across a volcanic soil chronosequence at Sierra del Chichinautzin, Mexico, to investigate differences in community structure at sites with different soil quality. Study sites were located on volcanic soils of different ages. Both aboveground and belowground fungal communities were compared for 3 years. Species abundance, richness, and diversity were compared among sites. Significant differences were found among the three sites for sporocarp abundance and biomass but not for total ECM root tips. The more diverse sporocarp community was found at the youngest, less fertile site. Dominant species at the sporocarp and ECM morphotype levels differed across the chronosequence. The largest proportion of sporocarp species was site-exclusive, which suggests that aboveground communities depend upon soil conditions. Contrarily, 85% of ECM morphotypes were present at least at two sites. The poor correspondence between the aboveground and belowground views of the ECM fungal community may be due to differences in sampling methodology and level of identification. Inocybe and Laccaria species were abundant fruiters at all sites, and as multisite fungi, they may be tested for inoculum efficiency to be used in reforestation programs in the surroundings of Mexico City.

Cambios en la composición de la comunidad fúngica de biopelículas sobre roca calcárea a través de una cronosecuencia en Campeche, México

“…The lowest evenness was obtained in the middle-aged biofilm, probably due to the presence of several dominant species, such as Curvularia lunata and Fusarium redolens (Table 3). We found higher diversity values in comparison to other studies on fungal communities colonizing distinct substrates of plant litter and endophytes (Collado et al, 2007;Reverchon et al, 2010). This diversity may be due to the establishment and accumulation of propagules on bare rock at a constant and rapid speed.…”

Soil factors influencing ectomycorrhizal sporome distribution in neotropical forests dominated by Pinus montezumae, Mexico

“…This concurs with the results of previous works which report a stronger effect of N on ECM aboveground communities (Jonsson et al 2000;Peter et al 2001b;Avis et al 2003), possibly due to a reduction of resource allocation to sporomes under N-enriched conditions (Lilleskov and Bruns 2001). The species composition of ECM belowground communities is therefore more likely to be related to soil fertility than to total abundance or richness (Reverchon et al 2010a). Weekly surveys throughout entire sporome production seasons are necessary in order to obtain accurate information about fungal community structure, as suggested by Vogt et al (1992) and Nara et al (2003).…”

“…Despite these discrepancies, we also found that N was negatively correlated with the species richness of ECM sporomes, which is in agreement with the findings of other authors (Jonsson et al 2000;). On the contrary, the species richness of root tip communities at the three sites was not affected by N (Reverchon et al 2010a). This concurs with the results of previous works which report a stronger effect of N on ECM aboveground communities (Jonsson et al 2000;Peter et al 2001b;Avis et al 2003), possibly due to a reduction of resource allocation to sporomes under N-enriched conditions (Lilleskov and Bruns 2001).…”

“…montezumae in these stands created ideal conditions to minimize the effects of host tree species on the relationships between soil quality and ECM community composition. In a previous study (Reverchon et al 2010a), we found that species composition of ECM fungal communities as a whole varied according to edaphic conditions. Therefore, we carried out an extensive macrofungi survey in order to analyze in more detail how some selected soil variables were influencing particular fungal species.…”

“…A gradient in pH and water availability exists across the soil chronosequence, the young site being drier and more acid than the old site. How this gradient may influence ECM community structure is further discussed in Reverchon et al (2010a).…”