TITLE:
Testing the Effect of Soil Heterogeneity on Arbuscular Mycorrhiza Fungi (AMF) Contribution to Plant Productivity
AUTHORS:
Samuel Ayesu, Grace Gyabaah
KEYWORDS:
Homogeneous, Heterogeneous, Arbuscular Mycorrhiza Fungi, Symbiosis, Clover, Grass
JOURNAL NAME:
Open Journal of Ecology,
Vol.4 No.6,
May
23,
2014
ABSTRACT: Most natural soils
are heterogeneous and nutrient availability and soil structure change greatly
over small distances. It is still unclear whether AMF are advantageous for
plants under such heterogeneous soil conditions. The objective of this study
was to determine whether diverse AMF community support host plant community
productivity in heterogeneous soil. It was also tested whether soil
heterogeneity affects plant productivity. This was carried out in a greenhouse experiment made up of two factors: soil
heterogeneity and AMF richness. Soil heterogeneity was simulated by mixing
three soil types (sand, field soil and organic soil) together (homogenous soil
(HM)), mixing them partly (semi homogenous (SH)) or keeping the three soil
types separate in three compartments within one pot (heterogeneous (HT)). AMF
richness was simulated by adding no AMF, one of four different AMF species
separately, or all four different AMF together. The pots were planted with a
mixture of Trifolium pratense and Lolium multiflorum. There was no effect of soil heterogeneity
on total plant biomass. However, the biomass of the individual plant species
was greatly affected by soil heterogeneity with Lolium being the most
abundant in the heterogeneous soil and Trifolium being the most abundant
in the homogenous soil. Total plant biomass did not increase with AMF richness.
Moreover, opposite to the hypothesis, AMF richness was not beneficial for plant
productivity in a heterogenous soil environment. However, there were
significant differences in plant biomass with different AMF treatments in the
SH and HT treatment indicating that effects of AMF on plant productivity are
influenced by soil type. These effects on yield and AMF reflect a combination
of local responses to growing conditions. The results show that AMF influence
on plant yield may not always be positive but is strongly dependent on
ecological elasticity and environmental condition.