MICROBIAL ACTIVITY

Microbial Activity under Snow Pack In Forest Soil

Introduction

The soil plays an important role in the C cycle and may represent an important source of CO2 and other greenhouse gases into the atmosphere. The total amount of C that contains the ground is two to three times that of atmospheric CO2. On the ground, this gas is produced mainly by metabolism of the micro flora and plant roots, where the microbial decomposition of organic compounds the most important process that generates it. During the decomposition part of C is returned to the atmosphere as CO2, while another is converted into other simpler compounds or stored in microbial structures themselves. (Singh, JS and Gupta, SR 1977)

CO2 fluxes between the atmosphere and soil play a key role in the functioning of the global cycle of C, so that the disturbance of the processes that regulate them may change the atmospheric CO2 concentration. In fact, activities that increase emissions of this gas into the atmosphere include changes in land use and overexploitation, including deforestation and silvicultural work. 1993; Merino et al. Intensive forest management significantly alters the properties of soil and environmental conditions, which can affect the activity of microorganisms and therefore in the decomposition of organic matter (Cortina and Vallejo, 1994) and the dynamics of soil CO2 (Mattson and Swank, 1989; Brumme, 1995). Thus, CO2 emissions can increase significantly after logging, although in some cases we have seen the opposite effect. (Linn DM, Doran JW 1984)

In this paper we analyze the effect of logging of a forest plantation and different site preparation techniques on the dynamics of soil C during the months of forestry work. We have studied the evolution of the decomposition of organic matter, CO2 emissions and changes in C associated with microbial biomass, which was associated with changes in soil environmental conditions produced by silvicultural management. (Joshi, M., Mer, GS, Singh, SP, Rawat, YS 1991)

Materials and methods

The study was conducted in a mature (25 years) of alpine tundra region pine located in America. It is a flat area located 500 m above sea level. The soil, developed on granodiorites, which corresponds to a Humic Cambisol and has an O horizon of 30-50 mm thick. It is a sandy loam soil with moderate organic matter content in upper horizon and strongly acid reaction. (Magid and NE Nielsen 1996)

In November, part of the plantation was felled. In the area that remained unlogged control plot was established (P), while the harvested area were delineated three subplots of 150 m2 each, which were performed three common techniques for preparing the ground for the next rotation. In the first plot (L) withdrew all logging residues (approximately 40 Mg ha-1), and the soil organic horizon (20.4 kg ha-1). In another (F), the remains were incorporated into the top 20 cm of mineral soil by milling (F). In a third (R), logging residue was distributed evenly over the surface of the plot. (Hutchinson, GL, and AE Mosier, 1981)

Soil temperature (10 cm) was ...