Infection intensity, spore density and inoculum potential of arbuscular mycorrhizal fungi decrease during secondary succession in tropical Brazilian ecosystems

Abstract

Abstract:Little is known about the relationship involving arbuscular mycorrhizal (AM) fungi and functional groups of plants that characterize different phases of tropical succession. We appraised the AM infection intensity of root cortex and spore density in the soil in sites over tropical successional gradients (grassland, secondary forest and mature forest) for several years in Araucaria, Atlantic and Pantanal ecosystems in Brazil. The intensity of AM infection decreased with advancing successional stages in all ecosystems and it was around 60–80% in early stages of succession, 37–56% in secondary forests and 19–29% in mature forests. Similarly, the AM spore number also decreased with advancing succession and was the highest in early stages (73–123 g−1), intermediate in secondary forests (32–54 g−1) and lowest in the mature forests (10–23 g−1). To verify whether such reductions influenced the potential of AM inoculum in soil, seedlings of Heliocarpus popayanensis (Malvaceae) were grown as test plants in soils obtained from five grasslands, five young secondary forests, and five mature forests in the Atlantic ecosystem. The soil inocula from the grasslands and secondary forests were 7.6 and 5.7 times more effective in stimulating seedling growth than inocula from the mature forests, respectively. Our results show that plant species in grasslands and young secondary forests stimulate the multiplication of AM fungi, leading to a higher potential of the AM inoculum. In later-successional stages, plant investment in AM fungi decreases and the potential of the AM inoculum is also reduced.

Shifts in symbiotic associations in plants capable of forming multiple root symbioses across a long‐term soil chronosequence

“…; Zangaro et al. ), as the optimum conditions for ECM fungi are between pH 4 and 5 (Aggangan et al. ; Yamanaka ).…”

Ocorrência de fungos micorrízicos em catuaba (Anemopaegma arvense (Vell.) Stell. ex de Souza - Bignoniaceae), uma planta medicinal do Cerrado em risco de extinção

“…Esses resultados corroboram com aqueles obtidos por Zangaro et al (2012) . ontudo, em estudos realizados por Alvarenga et al (1999), sobre a ocorrência de FMAs em solos de Cerrado, os resultados mostraram tendência à ocorrência de maior número de esporos em pastagens e menor em espécies nativas do Cerrado.…”

“…na conservação, armazenagem e ciclagem de nutrientes em ecossistemas florestais (Pereira et al, 1996, Zangaro et al, 2012. Considerando que a formação e o funcionamento das MAs e a ocorrência dos FMAs podem ser influenciados direta ou indiretamente por fatores relacionados à planta, ao solo, ao ambiente e manejo do ecossistema, os resultados obtidos neste trabalho em relação à quantidade de esporos corroboram com as respostas encontradas por Siqueira (1988), Grazziotti (1999), Miranda & Miranda (2001), Moreira & Siqueira (2002), Aidar et al (2004) e Miranda et al (2005).…”

“…Zangaro et al (2012) constataram que a intensidade de colonização de FMA diminuiu com o avanço dos estágios sucessionais em todos os ecossistemas estudados, sendo aproximadamente de 60-80% em estágios iniciais de sucessão, 37-56% em florestas secundárias e 19-29% em florestas maduras.…”

INFLUENCE OF MYCORRHIZAS, ORGANIC SUBSTRATES AND CONTAINER VOLUMES ON THE GROWTH OF Heliocarpus popayanensis Kunth

“…Knowledge of how tree species can establish symbiosis with AMF and the benefits generated is one of the keys to the problem of producing seedlings for successful forest ecological restoration (ZANGARO et al, 2012b).…”