Diversity and growth-effects of ectomycorrhizal fungi of a Nothofagus pumilio forest in the Andes of Southern Chile

Abstract

Chilean temperate rainforests have unique climatic, edaphic and biotic conditions, constituting pre-industrial blueprint ecosystems. Mycorrhizal associations play a central role in the biogeochemical processes of these ecosystems´ functioning. Baseline forest ecology studies are necessary in order to better understand diversity patterns, specifically regarding mycorrhizal symbiosis. Therefore, here we describe the vegetation characteristics and the mycorrhizal relationships of vascular plants in a Nothofagus pumilio forest. We also describe, via morphological methods, the ectomycorrhizal diversity present in this forest. Additionally, we determined whether ectomycorrhizal inoculation confers positive growth effects on N. pumilio seedlings. We found that from 46 vascular plant species identified in this study, 42 (91%) were mycorrhizal and of these 33 (72%) were associated with arbuscular mycorrhizae (AM), two (the dominant trees N. pumilio and N. dombeyi) were forming ectomycorrhizae (EM), five were associated with ericoid mycorrhizae, two with orchid mycorrhizae, and four were nonmycorrhizal. Additionally, 26 EM species were detected of which 15 belong to Cortinarius. Finally, there were clear differences in the growth of N. pumilio seedlings inoculated with the ectomycorrhizal fungus Laccaria laccata compared to noninoculated plants. We suggest that mycorrhizal fungi play a key role in seedling colonization of harsh environments such as the Andean treeline. RESUMENLos bosques templados lluviosos de Chile tienen condiciones climáticas, edáficas y bióticas únicas, constituyendo ecosistemas preindustriales modelo. Las asociaciones micorrízicas juegan un rol central en los procesos biogeoquímicos del funcionamiento de estos ecosistemas. Por lo tanto, en este estudio describimos las características de la vegetación y las relaciones micorrízicas de las plantas vasculares de un bosque de Nothofagus pumilio. También describimos, vía métodos morfológicos, la diversidad ectomicorrízica presente en este bosque. Adicionalmente, determinamos si inoculaciones ectomicorrízicas confieren efectos de crecimiento positivos a semilleros de N. pumilio. Encontramos que, de 46 especies de plantas vasculares identificadas en este estudio, 42 (91%) son micorrízicas, y de estas, 33 (72%) están formando micorrizas arbusculares (AM), dos (los árboles dominantes N. pumilio y N. dombeyi) están asociados con ectomicorrizas (EM), cinco están asociadas con micorrizas ericoides, dos con micorrizas orquioides, y cuatro fueron nomicorrizadas. Adicionalmente, 26 especies de EM fueron detectadas, de las cuales 15 pertenecen a Cortinarius. Finalmente, hubo claras diferencias en el crecimiento de los semilleros de N. pumilio inoculados con el hongo ectomicorrízico Laccaria laccata, comparados a plantas no inoculadas. Sugerimos que los hongos micorrízicos juegan un rol clave en la colonización de ambientes severos por juveniles, como en el límite altitudinal andino.

Ectomycorrhizal fungi and soil enzymes exhibit contrasting patterns along elevation gradients in southern Patagonia

“…These dwarfed, multistem trees exhibited higher leaf nutrient content coupled with increased rates of nutrient movement between roots and shoots. Our results support previous evidence that ECM associations adapted to high elevations and low soil pH may facilitate N accessibility at high elevations (Moeller et al ., ; Marín et al ., ). Both Clavulinaceae and Cortinariaceae were particularly abundant at the treeline (Fig.…”

Rescuing the ectomycorrhizal biodiversity associated with South American Nothofagaceae forest, from the 19th century naturalists up to molecular biogeography

“…We consider spore inoculation is the most realistic option for local nurseries that probably cannot afford the cost of mycelium production or purchase. Nonetheless, EcM taxa other than those proposed here have been reported from nurseries and naturally established Nothofagaceae seedlings as Descolea (Palfner et al, 2008;Valenzuela Flores et al, 2008;Álvarez et al, 2009;Fernández et al, 2015;Salgado Salomón et al, 2018a), Hebeloma (Fernández et al, 2015;Salgado Salomón et al, 2018a), Sebacina, Inocybe, Laccaria, Genea (Fernández et al, 2015;Marín et al, 2018), Tomentella (Kuhar et al, 2016;Fernández et al, 2013Fernández et al, , 2015Salgado Salomón et al, 2017, 2018a, Clavulinaceae (Fernández et al, 2015), Thelephorales (Fernández et al, 2015), Pyrenomataceae (Fernández et al, 2013;Salgado Salomón et al, 2018a). To broaden the perspective of EcM species best suited to inoculate nursery plants, especially for those with low fruiting frecuency, small spores production or corticioid habit, mycelium inoculum production, mycorrhizal infection and field performance tests will be required.…”

Arbuscular Mycorrhizal Fungi Associated with Bamboo Under Cerrado Brazilian Vegetation

“…Further studies need to incorporate these rhizospheric interactions when accounting for the AMF community composition and its effects on bamboo plant growth and other ecosystem processes. Also, when prospecting micro-propagation efforts of bamboo, the local AMF community should be taken into account, as local and specific mycorrhizal fungi may have better results on plant growth and survival than non-local and non-specific mycorrhizal fungi (Marín et al 2018); this specificity may be reflected on this study, as the AMF genus Sclerocystis was found in only one rhizospheric soil sample of A. verticillatum (Table 2). The northern and central areas of Brazil have been extremely understudied in terms of mycorrhizal ecology and biodiversity (Bueno et al 2017), albeit noticeable exceptions (de Assis et al 2018;Marinho et al 2019), most research has been concentrated in natural and agricultural ecosystems of the southern part of the country (Bueno et al 2017;Davison et al 2015).…”