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Summary: The biological and functional diversity of ectomycorrhizal (ECM) associations remain largely unknown in South America. In Patagonia, the ECM tree Nothofagus pumilio forms monospecific forests along mountain slopes without confounding effects of vegetation on plant–fungi interactions.To determine how fungal diversity and function are linked to elevation, we characterized fungal communities, edaphic variables, and eight extracellular enzyme activities along six elevation transects in Tierra del Fuego (Argentina and Chile). We also tested whether pairing ITS1 rDNA Illumina sequences generated taxonomic biases related to sequence length.Fungal community shifts across elevations were mediated primarily by soil pH with the most species‐rich fungal families occurring mostly within a narrow pH range. By contrast, enzyme activities were minimally influenced by elevation but correlated with soil factors, especially total soil carbon. The activity of leucine aminopeptidase was positively correlated with ECM fungal richness and abundance, and acid phosphatase was correlated with nonECM fungal abundance. Several fungal lineages were undetected when using exclusively paired or unpaired forward ITS1 sequences, and these taxonomic biases need reconsideration for future studies.Our results suggest that soil fungi in N. pumilio forests are functionally similar across elevations and that these diverse communities help to maintain nutrient mobilization across the elevation gradient. [ABSTRACT FROM AUTHOR]

Question: Does understorey richness, cover and biomass change during succession in abandoned Castor canadensis impoundments of riparian Nothofagus forests? Location: Magellanic Nothofagus forests at Tierra del Fuego National Park (54°50′32.4″ S, 68°32′11.5″ W), Argentina. Methods: Five meadows of different time since abandonment (1, 5, 6, 9 and 20 years ago) and two controls (pure N. pumilio and mixed N. pumilio -- N. betuloides forests) were sampled. Understorey variables (species richness, cover and biomass) in beaver meadows were measured at eight plots, as well as sapling and seedlings age and height. In control treatments, ten plots on each forest type characterized forest structure. Results: Beavers alter vegetation dynamics, modifying biomass and composition of the original forest communities. Richness, cover and biomass were significantly modified when compared to the original understorey. Ferns are the most affected group, while grasses became more abundant. Many species established in the impacted sectors, which did not grow in primary forests. Trees did not regenerate in impacted areas for long periods, and many understorey original species are missing. Nothofagus forests are not adapted to support a long-term beaver impact. Conclusions: Beavers modify the original ecosystem from closed forest to a grass- and sedge-dominated meadow, due to the lack of adaptive regeneration strategies in the Nothofagus forests. The maintenance of the present level of the beaver population is not sustainable over time, due to utilized and impacted tree biomass which could not be replaced by the natural dynamics of the forest ecosystem. [ABSTRACT FROM AUTHOR]