scholarly journals Intra-Annual Variation in Soil C, N and Nutrients Pools after Prescribed Fire in a Mississippi Longleaf Pine (Pinus palustris Mill.) Plantation

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
John R. Butnor ◽  
Kurt H. Johnsen ◽  
Christopher A. Maier ◽  
C. Dana Nelson

Prescribed fire is an essential tool that is widely used for longleaf pine (Pinus palustris Mill.) stand management; periodic burning serves to reduce competition from woody shrubs and fire-intolerant trees and enhance herbaceous diversity. Low-intensity, prescribed burning is thought to have minimal long-term impact on soil chemistry in southern pine forests, although few studies report the intra-annual variation in soil chemistry after burning. We monitored changes in C, N, oxidation resistant C (CR), pH and elemental nutrients in the forest floor and soil (0–5, 5–10 cm depths) before and after burning (1, 3, 6, 12 months) in a mature longleaf pine plantation at the Harrison Experimental Forest, near Saucier, Mississippi. Prescribed fire consumed much of the forest floor (11.3 Mg ha−1; −69%), increased soil pH and caused a pulse of C, N and elemental nutrients to flow to the near surface soils. In the initial one to three months post-burn coinciding with the start of the growing season, retention of nutrients by soil peaked. Most of the N (93%), Ca (88%), K (96%) and Mg (101%), roughly half of the P (48%) and Mn (52%) and 25% of the C lost from the forest floor were detected in the soil and apparently not lost to volatilization. By month 12, soil C and N pools were not different at depths of 0–5 cm but declined significantly below pre-burn levels at depths of 5–10 cm, C −36% (p < 0.0001), N −26% (p = 0.003), contrary to other examples in southern pine ecosystems. In the upper 5 cm of soil, only Cu (−49%) remained significantly lower than pre-burn contents by month 12, at depths of 5–10 cm, Cu (−76%), Fe (−22%), K (−51%), Mg (−57%), Mn (−82%) and P (−52%) remain lower at month 12 than pre-burn contents. Burning did not increase soil CR content, conversely significant declines in CR occurred. It appears that recovery of soil C and N pools post-burn will require more time on this site than other southern pine forests.

2004 ◽  
Vol 34 (3) ◽  
pp. 509-518 ◽  
Author(s):  
J Bauhus ◽  
T Vor ◽  
N Bartsch ◽  
A Cowling

Despite the importance of gaps in the dynamics and management of many forest types, very little is known about the medium- to long-term soil C and N dynamics associated with this disturbance. This study was designed to test the hypothesis that gap creation and lime application, a routine measure in many European forests to ameliorate soil acidity, lead to accelerated litter decomposition and thus a reduction in the forest floor and soil C and N pools. Four gaps were created in 1989 in a mature European beech (Fagus sylvatica L.) forest on acid soil with a moder humus, and lime (3 t dolomite·ha–1) was applied to two of these and surrounding areas. Litter and fine-root decomposition was measured in 1992–1993 and 1996–1998 using litterbags. Forest floor (L, F, and H layers) and mineral soil (0–40 cm) C and N pools were determined in 1989 and 1997. Eight years following silvicultural treatments, there was no change in C and N over the entire forest soil profile including forest floor. Reductions in the F and H layers in limed gaps were compensated for by increases in soil C and N in the surface (0–10 cm) mineral soil. Decomposition of F litter was significantly accelerated in limed gaps, leading to the development of a mull–moder, whereas gap creation alone had no effect on mass loss of F material in litterbags. Gap size disturbances in this acid beech forest appear to have minimal influences on soil C and N stocks. However, when combined with liming, changes in the humus form and vertical distribution of soil C and N may occur.


2020 ◽  
Author(s):  
Sonia C. Clemens ◽  
◽  
Mia Brkljaca ◽  
Delaina Pearson ◽  
C. Brannon Andersen

2021 ◽  
Vol 11 (5) ◽  
pp. 2139
Author(s):  
Junliang Zou ◽  
Bruce Osborne

The importance of labile soil carbon (C) and nitrogen (N) in soil biogeochemical processes is now well recognized. However, the quantification of labile soil C and N in soils and the assessment of their contribution to ecosystem C and N budgets is often constrained by limited information on spatial variability. To address this, we examined spatial variability in dissolved organic carbon (DOC) and dissolved total nitrogen (DTN) in a Sitka spruce forest in central Ireland. The results showed moderate variations in the concentrations of DOC and DTN based on the mean, minimum, and maximum, as well as the coefficients of variation. Residual values of DOC and DTN were shown to have moderate spatial autocorrelations, and the nugget sill ratios were 0.09% and 0.10%, respectively. Distribution maps revealed that both DOC and DTN concentrations in the study area decreased from the southeast. The variability of both DOC and DTN increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. The cokriging technique performed better than the ordinary kriging for predictions of DOC and DTN, which are highly correlated. This study provides a statistically based assessment of spatial variations in DOC and DTN and identifies the sampling effort required for their accurate quantification, leading to improved assessments of forest ecosystem C and N budgets.


Geoderma ◽  
2021 ◽  
Vol 399 ◽  
pp. 115109
Author(s):  
Paul L. Mudge ◽  
Jamie Millar ◽  
Jack Pronger ◽  
Alesha Roulston ◽  
Veronica Penny ◽  
...  
Keyword(s):  
Soil C ◽  

2018 ◽  
Vol 45 ◽  
pp. 00085
Author(s):  
Izabela Sówka ◽  
Yaroslav Bezyk ◽  
Maxim Dorodnikov

An assessment of C and N balance in urban soil compared to the natural environment was carried out to evaluate the influence of biological processes along with human-induced forcing. Soil C and N stocks were quantified on the samples (n=18) collected at 5 - 10 cm depth from dominated green areas and arable lands in the city of Wroclaw (Poland) and the relatively natural grassland located ca. 36 km south-west. Higher soil carbon and nitrogen levels (C/N ratio = 11.8) and greater microbial biomass C and N values (MBC = 95.3, MBN = 14.4 mg N kg-1) were measured in natural grassland compared with the citywide lawn sites (C/N ratio = 15.17, MBC = 84.3 mg C kg-1, MBN = 11.9 mg N kg-1), respectively. In contrast to the natural areas, the higher C and N concentration was measured in urban grass dominated soils (C = 2.7 % and N = 0.18 % of dry mass), which can be explained mainly due to the high soil bulk density and water holding capacity (13.8 % clay content). The limited availability of soil C and N content was seen under the arable soil (C = 1.23 %, N = 0.13 %) than in the studied grasslands. In fact, the significantly increased C/N ratios in urban grasslands are largely associated with land conversion and demonstrate that urban soils have the potential to be an important reservoir of C.


1992 ◽  
Vol 72 (3) ◽  
pp. 201-216 ◽  
Author(s):  
P. M. Rutherford ◽  
N. G. Juma

Modelling in soil ecological research is a means of linking the dynamics of microbial and faunal populations to soil processes. The objectives of this study were (i) to simulate bacterial-protozoan interactions and flows of C and N in clay loam Orthic Black Chernozemic soil under laboratory condtions; and (ii) to quantify the flux of C and N (inputs and outputs) through various pools using the simulation model. The unique features of this model are: (i) it combines the food chain with specific soil C and N pools, and (ii) it simultaneously traces the flows of C, 14C, N and 15N. It was possible to produce a model that fitted the data observed for the soil. The simulated CO2-C evolved during the first 12 d was due mainly to glucose addition (171 μg C g−1 soil) and cycling of C in the soil (160 μg C g−1 soil). During this interval, bacterial C uptake was 5.5-fold greater than the initial bacterial C pool size. In the first 12 d protozoa directly increased total CO2-C evolution by 11% and increased NH4-N mineralization 3-fold, compared to soil containing only bacteria. Mineralization of C and N was rapid when bacterial numbers were increased as a result of glucose addition. Key words: Acanthamoeba sp., modelling, N mineralization-immobilization, organic matter, Pseudomonas sp., Typic Cryoboroll


2021 ◽  
Author(s):  
John P McGuire ◽  
John S Kush ◽  
J Morgan Varner ◽  
Dwight K Lauer ◽  
J Ryan Mitchell

Abstract Efforts to restore longleaf pine (Pinus palustris Mill.) in the southeastern US require substantial artificial regeneration. Once established, important questions remain about when to introduce fire. We investigated the impact of initial planting density on tree branching and how prescribed fire might interact with tree architecture and survival. A particular focus was on how prescribed fires could “prune” lower branches. Lower density plantings (897 trees ha−1) had more and larger live lower branches than higher density plantings (2,243 trees ha−1). Fire was effective in pruning lower branches regardless of season burned, but fire in the growing season was more effective at pruning. Branches up to a height of 1.5 to 2 m were killed by fire. Fire applied in August caused greater damage with more needles scorched and/or consumed and more stem char. Prescribed fire did not impact longleaf pine tree survival. In general, fire applied to longleaf pine facilitated pruning lower branches that affect long-term wood quality, an additional argument for its utility in restoration and management of these ecosystems.


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