Microbial community structure and nutrient dynamics in forest soils colonized by bracken fern (Pteridium aquilinum)

Ecoloxía e Bioloxía Animal, Universidade de Vigo, Vigo, Spain
DOI
10.7287/peerj.preprints.1863v1
Subject Areas
Ecosystem Science, Soil Science
Keywords
Litter decomposition, Metabolic quotient, Microbial activity, Plant invasion, Nutrient cycling, Microbial community structure
Copyright
© 2016 Aira et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Aira M, Tato A, Domínguez J. 2016. Microbial community structure and nutrient dynamics in forest soils colonized by bracken fern (Pteridium aquilinum) PeerJ Preprints 4:e1863v1

Abstract

Bracken fern (Pteridium aquilinum) is one of the most successful plant colonizers of soils in temperate regions; however, its effects on microbial community structure and activity and nutrient dynamics remain poorly understood. We studied whether colonization of forest soil by bracken fern modifies the structure and function of the soil microbial communities and considered the implications for ecosystem functioning. For this purpose, we analyzed microbial community structure (PLFAs) and activity (basal respiration, metabolic quotient), litter decomposition and nutrient dynamics (C, N and P) in monospecific oak (Quercus robur L.), eucalyptus (Eucalyptus globulus Labill.) and maritime pine forests (Pinus pinaster Aiton) colonized by bracken fern. Colonization of forest soil by bracken fern led to a reduction in differences in microbial community structure, as revealed by principal component and cluster analysis, although samples from oak forests were grouped separately. According to this, bracken litter decomposed to a greater extent than native tree litter in pine forest soils, whereas the opposite was found in oak forest soils. Such differences were not observed in eucalyptus forest soils. Colonization by bracken fern affected C mineralization, with no difference between the different types of forest; however, both N and P mineralization were higher in oak than in the other types of forest. In conclusion, colonization by bracken fern homogenizes soil microbial community structure. Differences in the decomposability of bracken litter in the different forest systems suggest a high degree of metabolic specialization of soil microorganisms. Thus, the soil microorganisms associated with bracken are continuously driven to decompose the bracken litter. In the long-term this will alter nutrient cycling, slowing decomposition and enhancing sequestering of nutrients by bracken ferns.

Author Comment

This is a PeerJ submission for review.

Supplemental Information

Data from litter decomposition experiment

DOI: 10.7287/peerj.preprints.1863v1/supp-1