Substrate quality regulates density loss, cellulose degradation and nitrogen dynamics in downed woody debris in a boreal forest

Biochar and manure may be used to enhance soil quality and productivity for sustainable agriculture and forestry operations. However, the response of surface and belowground wood decomposition (i.e., soil processes) and nutrient flux to soil amendments is unknown, and more site-specific information about soil property responses is also essential. In a split-plot design, the soil was amended with three rates of manure (whole plot; 0, 3, and 9 Mg ha−1) and three rates of biochar (split-plot; 0, 2.5, and 10 Mg ha−1). Soil physical properties, nutrients, and enzyme activities were evaluated in two years. In addition, wood stakes of three species (poplar, triploid Populus tomentosa Carr.; aspen, Populus tremuloides Michx.; and pine, Pinus taeda L.) were installed both horizontally on the soil surface and vertically in the mineral soil to serve as an index of soil abiotic and biotic changes. Wood stake mass loss, nitrogen (N), phosphorus (P), and potassium (K) flux were tested. The high rate of both manure and biochar increased soil water content by an average of 18%, but the increase in total soil P, K, organic carbon (C) content, and enzyme activities were restricted to single sample dates or soil depths. Wood stakes decomposed faster according to stake location (mineral > surface) and species (two Populus > pine). On average, soil amendments significantly increased the mass loss of surface and mineral stakes by 18% and 5%, respectively, and it also altered wood stake nutrient cycling. Overall, the decomposition of standard wood stakes can be a great indicator of soil quality changes, and 10 Mg ha−1 of biochar alone or combined with 9 Mg ha−1 of manure can be used for long-term carbon sequestration in plantations with similar soil conditions to the present study.

Section: Wood Stake Nutrient Fluxmentioning

confidence: 99%

Enhancing Soil Quality of Short Rotation Forest Operations Using Biochar and Manure

Zhao

Liu

Page‐Dumroese

et al. 2022

“…The highest mortality level is observed in the unmanaged remote territories of Russian Asia and the areas in the southern part of the forest zone closest to the Mid-latitude ecotone. This depends upon the complex interactions of the regional specificity of the forest cover (i.e., age, species composition, productivity, level of forest transformation, vitality) under the impacts of diverse catastrophic and non-catastrophic agents [26,34,[46][47][48][49]. Based on our estimates, the tree mortality in NE forests in the years around 2010 was approximately 46% of the gross growth.…”

Section: Brief Overview Of State Of the Artmentioning

confidence: 99%

A Modelling System for Dead Wood Assessment in the Forests of Northern Eurasia

Shvidenko

Mukhortova

Kapitsa

et al. 2022

Self Cite

Dead wood, including coarse woody debris, CWD, and fine woody debris, FWD, plays a substantial role in forest ecosystem functioning. However, the amount and dynamics of dead wood in the forests of Northern Eurasia are poorly understood. The aim of this study was to develop a spatially distributed modelling system (limited to the territories of the former Soviet Union) to assess the amount and structure of dead wood by its components (including snags, logs, stumps, and the dry branches of living trees) based on the most comprehensive database of field measurements to date. The system is intended to be used to assess the dead wood volume and the amount of dead wood in carbon units as part of the carbon budget calculation of forests at different scales. It is presented using multi-dimensional regression equations of dead wood expansion factors (DWEF)—the ratio of the dead wood component volume to the growing stock volume of the stands. The system can be also used for the accounting of dead wood stock and its dynamics in national greenhouse gas inventories and UNFCCC reporting. The system’s accuracy is satisfactory for the average level of disturbance regimes but it may require corrections for regions with accelerated disturbance regimes.

“…Lignin, cellulose, and hemicellulose are the main structural components of Eucalyptus stump-root systems [10], and they constitute the main body of biomass. Generally, as CWD decomposes, cellulose and hemicellulose decrease, while lignin relatively increases [10,62]. The reason is that cellulose and hemicellulose are relatively simple carbon-containing high-molecular-weight polymers, so they are more likely to be exposed to microorganisms and decomposed.…”

Section: Factors Influencing Elemental Stocks In Stump-root Systemsmentioning

confidence: 99%

Nutrient Element Stocks and Dynamic Changes in Stump–Root Systems of Eucalyptus urophylla × E. grandis

Xie,

Liang,

Liu

et al. 2023

Stump–root systems consist of aboveground stumps and underground coarse roots after timber harvesting. Stump–root systems are the primary source of coarse woody debris (CWD) in plantations, and they play a crucial role in the material cycle, energy flow, and biodiversity of Eucalyptus plantation ecosystems. However, there is limited knowledge about the changes in elemental stock within this CWD type during decomposition. To address this gap, we conducted a study on Eucalyptus urophylla × E. grandis stump–root systems at various times (0, 1, 2, 3, 4, 5, and 6 years) after clearcutting. Our aim was to investigate the stock changes in eight elements (K, Ca, Mg, S, Fe, Mn, Cu, and Zn) within the stumps and coarse roots over time and their decay levels, and we analyzed the relationship between elemental stocks and the physical, chemical, and structural components of stump–root systems. Our findings revealed the following: (1) The majority of each element’s stock within the stump–root system was found in the coarse roots. The elemental stocks in both stumps and coarse roots decreased as time passed after clearcutting and as decay progressed. (2) Notably, the elemental stocks in stumps and coarse roots were significantly higher than in other treatments during the initial 0–2 years after clearcutting and at decay classes I and II. In terms of elemental stocks, stumps from all clearcutting times or decay classes had the highest K stock, followed by Ca and Fe. Mg, Mn, and S stocks were lower than the first three, while Zn and Cu stocks were very low. The ordering of elemental stocks from high to low in the stump–root systems generally aligned with that of the coarse roots. (3) The residual rates of K, Mg, and Mn stocks in the stump–root systems fit the negative exponential model well. It took approximately 1 to 3.5 years for a 50% loss of the initial stocks of these elements and 5 to 10 years for a 95% loss. (4) The large amount of biomass in the stump–root system is the long-term nutrient reservoir of plantations, and any factor related to biomass loss affects the magnitude and duration of the nutrient reservoir, such as N, P, stoichiometric ratios, density, water-holding capacity, and hemicellulose. These findings contribute to a better understanding of the nutrient elemental dynamics and ecological functions of stump–root systems in Eucalyptus plantations.