Carbon storage as affected by different site preparation techniques two years after mixed forest stand installation

Abstract

Aim of study: This study aims at evaluating the impact of site preparation techniques prior to plantation on carbon storage and distribution in a young mixed stand of Pseudotsuga menziesii (PM) and Castanea sativa (CS).Area of study: The experimental field was established near Macedo de Cavaleiros, Northern Portugal, at 700 m elevation, mean annual temperature 12°C and mean annual rainfall 678 mm.Material and methods: The experimental layout includes three replicates, where the different treatments corresponding to different tillage intensities were randomly distributed (high, moderate and slight intensity), in plots with an area of 375 m 2 each. Twenty six months after forest stand installation, samples of herbaceous vegetation (0.49 m 2 quadrat), forest species (8 PM and 8 CS) and mineral soil (at 0-5, 5-15, 15-30 and 30-60 cm depth) were collected in 15 randomly selected points in each treatment, processed in laboratory and analyzed for carbon by elemental carbon analyzer.Main results: The results obtained showed that: (i) more than 90% of the total carbon stored in the system is located in the soil, increasing in depth with tillage intensity; (ii) the contribution of herbaceous vegetation and related roots to the carbon storage is very low; (iii) the amount of carbon per tree is higher in CS than in PM; (iv) the global carbon storage was affected by soil tillage generally decreasing with the increase of tillage intensity. Accordingly, carbon storage capacity as affected by the application of different site preparation techniques should be a decision support tool in afforestation schemes.

Forest management and carbon sequestration in the Mediterranean region: A review

“…Soil preparation techniques could also cause a temporary reduction in soil carbon stock in the short-or mediumterm and the net effects on the soil of afforestation may be delayed due to the mixing of forest floor and mineral soil along with the exposure of the latter, which leads to an increase in decomposition rates (Jandl et al, 2007). Carbon losses are higher as the intensity of the soil disturbance increases (e.g., Johansson, 1994;GartziaBengoetxea et al, 2011;Fonseca et al, 2014;Wang et al, 2016). Intense soil preparation techniques, e.g.…”

Impact of tree species replacement on carbon stocks in a Mediterranean mountain area, NE Portugal

“…5 presents carbon stocks in the mineral soil layers analysed. At all depths, soil carbon accumulation under PM and PN species is significantly lower than that under QP species, which can be justified by several effects as site preparation (Fonseca et al, 2014;Ferré et al, 2014), management practices (Zhang et al, 2016) and the nature of the litterfall produced by each tree species (Vesterdal et al, 2013;Cools et al, 2014;Zhang et al, 2016;Fonseca and Figueiredo, 2018). These factors may promote the breakdown of soil aggregates, affect soil biological activity and, consequently, the mineralization rate of organic residues in the forest floor and of soil organic matter (Gonçalves et al, 2013;Herrero et al, 2016;Fonseca and Figueiredo, 2018).…”

“…It should be noted that the PN is also considered a fast-growing species; nevertheless, the characteristics of this stand differ from those of the PM stand, the latter showing larger tree density (number of trees per hectare) and higher canopy cover (Table 1), both factors affecting carbon storage (Fonseca et al, 2004;Park, 2015). Fast-growing species, such as PM and PN, are more effective in carbon accumulation in biomass (Vallet et al, 2009;Gonçalves et al, 2013;Fonseca et al, 2014). According to Park (2015), modifications in vegetation cover, even when replacement involves species closely connected to each other, may produce important differences in total carbon stocks, as well as in the distribution of carbon across ecosystem compartments.…”

“…It should be noted that, in temperate forest ecosystems, a greater accumulation of carbon in the aboveground biomass, as compared to the belowground, is commonly referred (e.g. Peichl and Arain, 2006;Vallet et al, 2009;Fonseca et al, 2014;Chen et al, 2016). The carbon stored in tree biomass increased for both introduced species (PM and PN), reaching values that exceed those recorded for QP in 35 Mg C ha −1 or an average of 1.2 Mg C ha −1 year −1 in PN (all increment in aboveground biomass) and 116 Mg C ha −1 or an average of 3.9 Mg C ha −1 year −1 in PM (84 Mg C ha −1 in aboveground biomass and 32 Mg C ha −1 in belowground biomass).…”

“…Disturbances that may occur in the soil such as changing vegetation cover, fires and management practices, influence in a long term the ecosystems sustainability and their ability to provide ecosystem services, such as carbon storage (e.g. Lal, 2005;Fonseca et al, 2014;Ferré et al, 2014;Chen et al, 2016;Sil et al, 2017;Fonseca and Figueiredo, 2018). The highest loss was recorded in the surface layer (0-5 cm; 11-15 Mg C ha −1 ), which may be related to a faster process of organic matter mineralization and gas exchanges with…”