Bouncing back: plant-associated soil microbes respond rapidly to prairie establishment.

Anna J Herzberger,Randall D Jackson,David S Duncan,Shuijin Hu

doi:10.1371/journal.pone.0115775

Abstract

It is well established that soil microbial communities change in response to altered land use and land cover, but less is known about the timing of these changes. Understanding temporal patterns in recovering microbial communities is an important part of improving how we assess and manage reconstructed ecosystems. We assessed patterns of community-level microbial diversity and abundance in corn and prairie plots 2 to 4 years after establishment in agricultural fields, using phospholipid fatty acid biomarkers. Principal components analysis of the lipid biomarkers revealed differing composition between corn and prairie soil microbial communities. Despite no changes to the biomass of Gram-positive bacteria and actinomycetes, total biomass, arbuscular mycorrhizal fungi biomass, and Gram-negative bacteria biomass were significantly higher in restored prairie plots, approaching levels found in long-established prairies. These results indicate that plant-associated soil microbes in agricultural soils can shift in less than 2 years after establishment of perennial grasslands.

Highlights

Soil microbial communities are a vital component of terrestrial ecosystems because of their key roles in nutrient cycling [1], modification of plant community composition [2], regulation of plant productivity [3], and decomposition of organic matter [4]
Phospholipid fatty acids (PLFAs) decompose rapidly after cell death, allowing them to approximate the active portion of the microbial community at the time of sampling [12, 18]
This can be extremely helpful for studying the temporal complexity of plant-microbe interactions, given the high rates of dormancy observed among soil microorganisms [20]

Summary

Introduction

Soil microbial communities are a vital component of terrestrial ecosystems because of their key roles in nutrient cycling [1], modification of plant community composition [2], regulation of plant productivity [3], and decomposition of organic matter [4]. Physical disruption of the soil through tillage can increase plant productivity by liberating nutrients previously tied up in soil organic matter [12], and damaging hyphae-producing microorganisms such as fungi and actinomycetes [6] These changes in plant resource allocation come at the expense of soil organic matter and microbial biomass [6, 13]. PLFAs decompose rapidly after cell death, allowing them to approximate the active portion of the microbial community at the time of sampling [12, 18] This can be extremely helpful for studying the temporal complexity of plant-microbe interactions, given the high rates of dormancy observed among soil microorganisms [20]. We were interested in whether and how these systems diverged over time during the establishment phase of these perennial crops

Methods

Results and Discussion

Conclusions