Hartman, M.

Ilvesniemi, H.

Murto, T.

Jukuri

IntroductionThe relationship between production and decomposition determines whether a forest site is a sink or a source of atmospheric CO2, but the absolute or relative contributions of photosynthetic and respiratory fluxes in forests managed in different ways are not yet well known. Forest harvesting reduces the amount of the living stand biomassand the corresponding amount of accumulated atmospheric carbon while the amount of recent plant litter increases. In addition to clear-cutting and residue removal, the site preparation also affects the decomposition conditions of the soil organic matter.  The soil CO2 efflux of each treatment replicate was measured from 6 spots within every above described treatment area. The spots that were chosen represented:1. Undisturbed microsites (resembling ground vegetation and humus before treatment)2. Disturbed microsites (ground vegetation and humus clearly affected by harvesting operation),3. Mounded microsites (soil preparation leaving no vegetation or humus)4. Undisturbed microsites in uncut control forestThe soil CO2 measurements were repeated during each vegetation period between 2007 (which was a calibration year) and 2012.In this presentation, we compare the soil respiration observations of the different clear-cut treatments by subtracting them from the mean values of the controls for each block of each experiment and year by converting the control to represent 0.Results and discussionThe overall mean soil CO2 respiration of the controlswas 1.01 (SD ±0.42),0.92 (SD±0.44) and 0.72 (SD±0.24) g CO2 m2 h-1 in the Anjalankoski, Längelmäkiand Paltamo respective experiments. The differences in the soil respiration between traditional clear-cutting and logging residue harvesting of different intensities are quite small, while the differences between the different microsites are more pronounced (fig 3 a and b). So far, the soil CO2 respiration rates of none of the treatments have reached the same level as in the uncut forest. In Paltamo the differences in soil respiration between control and treatments are getting smaller.Soil CO2 respiration of forest floor after whole-tree harvesting of spruce stands1 Naturresursinstitutet, Email: markus.hartman@luke.fi,  hannu.ilvesniemi@luke.fi2 Forststyrelsen, Email: tanja.murto@metsa.fiHartman, M1., Murto, T2 . and Ilvesniemi , H.1Fig 1. Aerial image of block 3 of the Längelmäki experiment with the  clear-cut treatments in the middle of the figure. The control forest is on the right side of the clear-cut area. (Map site © Land Survey of Finland)Fig. 2. An undisturbed microsite prepared for soil respiration measurement (photo T. Murto).Anjalankoski Längelmäki Paltamoa200720082009201020112012Year-2-1012Soil CO2 (g m-2 h-1) differences  200720082009201020112012Year-2-1012Soil CO2 (g m-2 h-1) differences  5.4.3.2.1.Treatments200720082009201020112012Year-2-1012Soil CO2 (g m-2 h-1) differences b 200720082009201020112012Year-2-1012Soil CO2 (g m-2 h-1) differences 200720082009201020112012Year-2-1012Soil CO2 (g m-2 h-1) differences  4.3.2.1.Microsites200720082009201020112012Year-2-1012Soil CO2 (g m-2 h-1) differencesFig 3. Differences (± SE) in soil CO2 respiration (g m2 h-1) between the controls and the different treatments (a) and the different microsites (b) during the monitoring years. 2007 was a calibration year. The different treatments in figures (a) and (b) are described in the text.Material and methodsThis study was carried out on three experimental areas located in Paltamo (North Central Finland), Längelmäki(South Central Finland) and Anjalankoski (SE Finland). Before clear-cut and treatments in 2008, the study sites were mature high-productive mesic spruce forest stands. The treatments, which were repeated with three (Längelmäki) or four (Anjalankoski, Paltamo) replicates on each location were: 1. Uncut forest (control); 2. Clear-cut, no soil preparation and no planting;(not measured for CO2) 3. Clear-cutting, patch mounding, spruce plantation; 4. Clear-cutting, 70% logging residue removal, patch mounding, spruce plantation; 5. Clear-cutting, 70% logging residue removal, stump removal (25 stumps/ha left), patch mounding, spruce plantation; 6. Clear-cutting, 100% logging residue removal, 100% stump removal, patch mounding, spruce plantation. The aim of this study was to quantify soil CO2 effluxes from clear-cut boreal forests managed in different ways after clear-cutting.  

Soil CO2 respiration of forest floor after whole-tree harvesting of spruce stands

Abstract

Similar works

Full text

Available Versions

Jukuri