Physiological, biochemical and molecular responses of the soil microbial community after afforestation of pastures with Pinus radiata

• Published in: Soil biology & biochemistry 2009-08, Vol.41 (8), p.1642-1651
• Main Authors: Macdonald, Catriona A., Thomas, Nadine, Robinson, Lucinda, Tate, Kevin R., Ross, Des J., Dando, John, Singh, Brajesh K.
• Format: Article
• Language: English
• Subjects: Afforestation; Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; community structure; fatty acid composition; Fundamental and applied biological sciences. Psychology; land use change; Microbial community structure; Microbial function; Microbiology; pastures; phospholipids; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Pinus radiata; population size; principal component analysis; restriction fragment length polymorphism; soil bacteria; soil chemical properties; soil ecology; soil fungi; soil microorganisms; soil physical properties; Soil physico-chemical properties; Soil science; volcanic soils
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2009.05.003

Afforestation and deforestation are key land-use changes across the world, and are considered to be dominant factors controlling ecosystem functioning and biodiversity. However, the responses of soil microbial communities to these land-use changes are not well understood. Because changes in soil microbial abundance and community structure have consequences for nutrient cycling, C-sequestration and long-term sustainability, we investigated impacts of land-use change, age of stand and soil physico-chemical properties on fungal and bacterial communities and their metabolic activities. This study was carried out at four sites in two geographical locations that were afforested on long-established pastures with Pinus radiata D. Don (pine). Two of the sites were on volcanic soils and two on non-volcanic soils and stand age ranged from 5 to 20 y. Microbial communities were analysed by biochemical (phospho-lipid fatty acids; PLFA) and molecular (multiplex-terminal restriction fragment length polymorphism; M-TRFLP) approaches. Both site and stand age influenced microbial properties, with changes being least detectable in the 5-y-old stand. Land use was a key factor influencing soil metabolic activities as measured by physiological profiling using MicroResp. Pasture soils had higher microbial biomass ( P