The mycorrhizal contribution to plant productivity, plant nutrition and soil structure in experimental grassland

Abstract

Summary• Previous studies have shown that arbuscular mycorrhizal fungi (AMF) can influence plant diversity and ecosystem productivity. However, little is known about the effects of AMF and different AMF taxa on other important community properties such as nutrient acquisition, plant survival and soil structure.• We established experimental grassland microcosms and tested the impact of AMF and of different AMF taxa on a number of grassland characteristics. We also tested whether plant species benefited from the same or different AMF taxa in subsequent growing seasons.• AMF enhanced phosphorus acquisition, soil aggregation and survival of several plant species, but AMF did not increase total plant productivity. Moreover, AMF increased nitrogen acquisition by some plant species, but AMF had no effect on total N uptake by the plant community. Plant growth responses to AMF were temporally variable and some plant species obtained the highest biomass with different AMF in different years. Hence the results indicate that it may be beneficial for a plant to be colonized by different AMF taxa in different seasons.• This study shows that AMF play a key role in grassland by improving plant nutrition and soil structure, and by regulating the make-up of the plant community.

Mycorrhizal fungi suppress aggressive agricultural weeds

“…Planting design was randomized 63 times and assigned to each microcosm. This approach was chosen to avoid potential differences among treatments being confounded by neighbourhood interactions and initial plant species composition (van der Heijden et al 2006). Seedlings that died within four weeks after planting were replaced so that each microcosm with sunflower and weeds contained 38 seedlings after 4 weeks.…”

“…Gerdemann & Trappe, isolate IMA1 from UK (AMF A), Glomus coronatum Giovannetti, isolate IMA3 (AMF B) and Glomus intraradices Schenck & Smith, isolate BEG 21 (AMF C). AMF A and B were obtained from pot-cultures maintained in the collection of the Department of Crop Plant Biology, University of Pisa, Italy and AMF C originated from Switzerland (see van der Heijden et al 2006 for a description). Inoculum of each isolate was propagated for approximately three months on Helianthus annuus in pots filled with a sterilized mixture of loamy soil and terra green (1:1).…”

“…It is still unclear whether weeds respond differently to different AMF and whether AM fungal diversity can suppress weed growth; in contrast to the positive effects of AM fungal diversity on some plant species (e.g. van der Heijden et al 2006;Maherali and Klironomos 2007). Several studies have shown that the composition and diversity of AM fungal communities in agricultural ecosystems depend on land use intensity, crop rotation, fertility level and tillage intensity (Alguacil et al 2008;Oehl et al 2003Oehl et al , 2004Hijri et al 2006).…”

Mutualism breakdown in breadfruit domestication

“…Recent studies have shown that AM fungal species are functionally distinct, in that some taxa provide disease resistance and others enhance nutrient supply to plants [13]. Furthermore, the diversity of AM fungi can potentially influence plant fitness, community structure, biodiversity, ecosystem productivity and variability [11,[13][14][15]. The beneficial effects of AM fungi on plant growth have led to the development of AM fungi as bioinoculants for forestry, agriculture and horticulture [16].…”

“…AM fungi play a key role in soil fertility, structure and ecology [10][11][12]. Recent studies have shown that AM fungal species are functionally distinct, in that some taxa provide disease resistance and others enhance nutrient supply to plants [13].…”