The influence of decomposing logs on soil biology and nutrient cycling in an old-growth mixed coniferous forest in Oregon, U.S.A.

2003 ◽  
Vol 33 (11) ◽  
pp. 2193-2201 ◽  
Author(s):  
J DH Spears ◽  
S M Holub ◽  
M E Harmon ◽  
K Lajtha
Keyword(s):  
Forest Floor ◽  
Woody Debris ◽  
Coniferous Forest ◽  
Water Soluble ◽  
Soil Biology ◽  
Soil C ◽  
Long Term Effect ◽  
Floor Control ◽  
Water Soluble Organic Carbon ◽  
Mineral Soils

This study investigated the effect of coarse woody debris (CWD) on mineral soils at the H.J. Andrews Experimental Forest in the central Cascade Range of Oregon, U.S.A. Nutrients in CWD leachates were compared with (i) forest floor (control) leachates, (ii) over a decay chronosequence, and (iii) among CWD of four species. There were few differences among CWD leachates and forest floor leachates. Soils under CWD were warmer but not wetter than control soils. Water-soluble organic carbon was higher in soils under CWD than in controls at 5–15 cm depth (p < 0.02), but soil C concentrations did not differ. Gross N mineralization was faster in control soils. We found no differences in N, P, microbial biomass, Biolog plate assays, or enzyme activity in soils. Nutrient leachate differences among CWD species were small. Differences in solutions and in soils among CWD and controls were largest during the middle decay classes. This study suggests that either (i) CWD has no long-term effect and does not contribute large amounts of organic matter to the soil profile or (ii) the effect of CWD is so prolonged that no spatial affect is noticeable because all soils have been affected by CWD at some time.

Comparison of coniferous forest carbon stocks between old-growth and young second-growth forests on two soil types in central British Columbia, Canada

2005 ◽  
Vol 35 (6) ◽  
pp. 1411-1421 ◽  
Author(s):  
Arthur L Fredeen ◽  
Claudette H Bois ◽  
Darren T Janzen ◽  
Paul T Sanborn
Keyword(s):  
British Columbia ◽  
Forest Floor ◽  
Woody Debris ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Old Growth ◽  
Soil C ◽  
Old Growth Forest ◽  
Second Growth ◽  
C Stocks

Carbon (C) stocks were assessed for hybrid interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.)-dominated upland forests within the Aleza Lake Research Forest in central British Columbia, Canada. Four old-growth (141–250 years old) and four young second-growth (<20 years old) forest plots were established on the two dominant soil texture types, coarse and fine, for a total of 16 plots. Mean total C stocks for old-growth stands ranged from 423 Mg C·ha–1 (coarse) to 324 Mg C·ha–1 (fine), intermediate between Pacific Northwest temperate forests and upland boreal forests. Total C was lower in second-growth stands because of lower tree (mostly large tree stem), forest floor, and woody debris C stocks. In contrast, old-growth forest-floor C stocks ranged from 78 Mg C·ha–1 (coarse) to 35 Mg C·ha–1 (fine), 2.9- and 1.2-fold higher than in corresponding second-growth stands, respectively. Woody debris C stocks in old-growth stands totaled 35 Mg C·ha–1 (coarse) and 31 Mg C·ha–1 (fine), 2.7- and 3.4-fold higher than in second-growth stands, respectively. Mineral soil C to 1.07 m depth was similar across soil type and age-class, with totals ranging from 115 to 106 Mg C·ha–1. Harvesting of old-growth forests in sub-boreal British Columbia lowers total C stocks by 54%–41%.

scholarly journals Effects of land use change from natural forest to plantation on C, N and natural abundance of 13C and 15N along a climate gradient in eastern China

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mbezele Junior Yannick Ngaba ◽  
Ya-Lin Hu ◽  
Roland Bol ◽  
Xiang-Qing Ma ◽  
Shao-Fei Jin ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Forest Floor ◽  
Eastern China ◽  
Mineral Soil ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Natural Forests ◽  
Soil C ◽  
Mineral Soils

Abstract Soil C and N turnover rates and contents are strongly influenced by climates (e.g., mean annual temperature MAT, and mean annual precipitation MAP) as well as human activities. However, the effects of converting natural forests to intensively human-managed plantations on soil carbon (C), nitrogen (N) dynamics across various climatic zones are not well known. In this study, we evaluated C, N pool and natural abundances of δ13C and δ15N in forest floor layer and 1-meter depth mineral soils under natural forests (NF) and plantation forest (PF) at six sites in eastern China. Our results showed that forest floor had higher C contents and lower N contents in PF compared to NF, resulting in high forest floor C/N ratios and a decrease in the quality of organic materials in forest floor under plantations. In general, soil C, N contents and their isotope changed significantly in the forest floor and mineral soil after land use change (LUC). Soil δ13C was significantly enriched in forest floor after LUC while both δ13C and δ15N values were enriched in mineral soils. Linear and non-linear regressions were observed for MAP and MAT in soil C/N ratios and soil δ13C, in their changes with NF conversion to PF while soil δ15N values were positively correlated with MAT. Our findings implied that LUC alters soil C turnover and contents and MAP drive soil δ13C dynamic.

Changes in carbon storage of broadcast burn plantations over 20 years

2007 ◽  
Vol 87 (1) ◽  
pp. 93-102 ◽  
Author(s):  
J M Kranabetter ◽  
A M Macadam
Keyword(s):  
Lodgepole Pine ◽  
Woody Debris ◽  
Mineral Soil ◽  
Biomass Accumulation ◽  
Prescribed Burn ◽  
Soil C ◽  
C Storage ◽  
C Stocks ◽  
Mineral Soils ◽  
Forest Floors

The extent of carbon (C) storage in forests and the change in C stocks after harvesting are important considerations in the management of greenhouse gases. We measured changes in C storage over time (from postharvest, postburn, year 5, year 10 and year 20) in logging slash, forest floors, mineral soils and planted lodgepole pine (Pinus contorta var. latifolia) trees from six prescribed-burn plantations in north central British Columbia. After harvest, site C in these pools averaged 139 Mg ha-1, with approximately equal contributions from mineral soils (0–30 cm), forest floors and logging slash. Together these detrital pools declined by 71 Mg C ha-1, or 51% (28% directly from the broadcast burn, and a further 23% postburn), in the subsequent 20 yr. Postburn decay in logging slash was inferred by reductions in wood density (from 0.40 to 0.34 g cm-3), equal to an average k rate of 0.011 yr-1. Losses in forest floor C, amounting to more than 60% of the initial mass, were immediate and continued to year 5, with no reaccumulation evident by year 20. Mineral soil C concentrations initially fluctuated before declining by 25% through years 10 and 20. Overall, the reductions in C storage were offset by biomass accumulation of lodgepole pine, and we estimate these plantations had become a net sink for C before year 20, although total C storage was still less than postharvest levels. Key words: C sequestration, forest floors; coarse woody debris; soil organic matter

Distribution of water-soluble organic carbon in an aspen forest soil

1996 ◽  
Vol 26 (7) ◽  
pp. 1266-1272 ◽  
Author(s):  
W.Z. Huang ◽  
J.J. Schoenau
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Water Soluble ◽  
Organic Layer ◽  
Litter Fall ◽  
Organic C ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon ◽  
Prince Albert National Park ◽  
Aspen Forest

The purpose of this study was to characterize the quantity, distribution, and variance of water-soluble organic C (WSOC) in a soil under trembling aspen (Populustremuloides Michx.) in the southern boreal forest of Canada. WSOC was determined monthly from May to October 1994 in the forest floor horizons (L, F, H) and mineral soil (Ae) of an aspen stand in Prince Albert National Park, Saskatchewan. The concentration of WSOC varied considerably with profile depth, but varied little among the slope positions and aspects. The L horizon had the highest WSOC concentration (425–8690 mg•kg−1 ovendried soil), followed by the F, H, and Ae horizons. The concentration of WSOC in the Ae horizon was significantly related to the concentration in forest floor horizons above. Water-soluble organic C in the Ae horizon likely was derived from the overlying organic layer by leaching. In a laboratory incubation, the rate of WSOC release (the net result of release and uptake) during incubation decreased continuously over time, but in the field, the rate of WSOC release decreased slightly early in the growing season, but increased later in the season as new litter fall reached the forest floor. This indicates that litter fall is a major factor in the replenishment of WSOC in aspen forest stands.

STORAGE EFFECTS ON NUTRIENT MINERALIZATION IN CONIFEROUS FOREST FLOOR SAMPLES

1980 ◽  
Vol 60 (3) ◽  
pp. 517-525 ◽  
Author(s):  
P. A. ARP ◽  
H. B. KING ◽  
H. H. KRAUSE
Keyword(s):  
Forest Floor ◽  
Room Temperature ◽  
Coniferous Forest ◽  
Water Soluble ◽  
Total N ◽  
Nutrient Mineralization ◽  
Storage Effects ◽  
Soluble P ◽  
Subsequent Storage ◽  
A Minor

Forest floor samples were obtained from three mature, even-aged, naturally regenerated conifer stands which varied with respect to drainage and indigenous soil fertility. Field moist subsamples were stored for 200 days in a refrigerator maintained at 4 °C and in a freezer maintained at − 10 °C; in addition, forest floor samples, dried at 60 °C for 48 h, were stored at room temperature. Subsamples were extracted initially and at predetermined time intervals with 2 N KCl (to determine mineral NH4+-N and NO3−-N), with neutral 1 N ammonium acetate (to determine water-soluble + exchangeable K, Ca, and Mg), and with distilled water (to determine soluble P). At 4 °C, extractable NH4+-N changed little during the first week of storage but increased steadily thereafter at rates which appeared to increase with increasing total N. Nitrification, present only in the sample taken from the most fertile site, commenced after 40 days of refrigerated storage. Concentrations of soluble P decreased initially, but rose thereafter at low, moderate, and high rates depending on total P. Freezing changed mineral NH4+-N to a minor extent, whereas NO3−-N was not affected. Concentrations of soluble P increased steadily during the first 2 mo of storage at − 10 °C. Levels of extractable K, Ca, and Mg were not affected by refrigeration and by length of storage time, but freezing increased extractable K considerably. Drying at 60 °C for 48 h produced abrupt increases in exchangeable + water-soluble nutrient levels. Further changes, however, were not observed during subsequent storage at room temperature.

scholarly journals A Stand-Level Comparison of Carbon and Nitrogen Distribution in an Exotic Japanese Cedar Plantation and a Natural Oak Stand

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 963
Author(s):  
Gyeongwon Baek ◽  
Eun-Ji Bae ◽  
Choonsig Kim
Keyword(s):  
Aboveground Biomass ◽  
Forest Floor ◽  
Japanese Cedar ◽  
Stem Bark ◽  
Soil C ◽  
C Stocks ◽  
C And N ◽  
Japanese Cedar Plantation ◽  
The Difference ◽  
Mineral Soils

This study compared carbon (C) and nitrogen (N) distribution at a stand level in an exotic Japanese cedar (Cryptomeria japonica D. Don) plantation and a natural Serrata oak (Quercus serrata Murray) stand growing under similar site conditions in South Korea. The aboveground biomass (stems, branches, and leaves) of 20 trees (10 of each species), the forest floor, and the mineral soils to a depth of 30 cm were sampled to determine C and N concentrations. Except in branches, C concentrations were significantly higher (p < 0.05) in the Japanese cedar plantation than in the Serrata oak stand, whereas N concentrations, except in the stem bark, were significantly lower in the Japanese cedar plantation. Reforestation with an exotic coniferous species significantly increased the C stocks in the aboveground biomass and the N stocks in the forest floor and mineral soils compared with a natural oak stand. The N stocks in the aboveground biomass were dependent on either the N concentrations or the C stocks in the tree components, whereas soil C and N stocks were negatively related to soil fertility parameters such as C/N ratio. Although it is uncertain which factors are responsible for the difference in aboveground C and soil N stocks following the establishment of Japanese cedar plantations on former natural Serrata oak stands, tree replacement may have an impact on C and N allocation within different forest compartments.

scholarly journals Substrate effects on distribution, biomass allocation, and morphology of forest understory plants

Botany ◽  
2008 ◽  
Vol 86 (10) ◽  
pp. 1133-1142 ◽  
Author(s):  
Laura J. Six ◽  
Charles B. Halpern
Keyword(s):  
Biomass Allocation ◽  
Forest Floor ◽  
Life Histories ◽  
Plant Biomass ◽  
Woody Debris ◽  
Coniferous Forest ◽  
Physical Structure ◽  
Forest Understory ◽  
Stable Substrate ◽  
And Performance

Relationships between rooting substrate and the distribution and performance of forest plants are inadequately understood. We tested whether understory species in a dense coniferous forest were associated with coarse woody debris (CWD) or forest floor. In addition, for three species with differing substrate associations ( Vaccinium parvifolium Smith, Tiarella trifoliata L., and Maianthemum dilatatum (Wood) Nels. and Macbr., we excavated individuals rooted in CWD and forest floor, and compared biomass allocation and plant morphological traits. Substrate samples were also tested for moisture content. Of 29 species tested, 18 (62%) showed positive associations with forest floor and 6 (21%) with CWD. Forest floor is a more predictable and stable substrate; in these forests it also supports lower moss cover that can inhibit seedling establishment. As expected, plants rooted in forest floor (which was drier) allocated greater biomass to belowground structures. Root-system traits, however, did not suggest plasticity in response to resource availability. Instead, the physical structure of logs may constrain root systems in CWD. In addition, total plant biomass did not differ between substrates suggesting that under low light, species may be incapable of responding to differences in belowground resources. Alternatively, substrate associations may develop earlier in the life histories of these plants via differential germination and survival.

scholarly journals Desiccation time and rainfall control gaseous carbon fluxes in an intermittent stream

2021 ◽  
Author(s):  
Maria Isabel Arce ◽  
Mia M. Bengtsson ◽  
Daniel von Schiller ◽  
Dominik Zak ◽  
Jana Täumer ◽  
...  
Keyword(s):  
Water Soluble ◽  
Intermittent Flow ◽  
Dry Period ◽  
Intermittent Stream ◽  
Aerobic Activity ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon ◽  
Microbial C ◽  
Global Biogeochemical Cycles ◽  
The Impact

AbstractDroughts are recognized to impact global biogeochemical cycles. However, the implication of desiccation on in-stream carbon (C) cycling is not well understood yet. We subjected sediments from a lowland, organic rich intermittent stream to experimental desiccation over a 9-week-period to investigate temporal changes in microbial functional traits in relation to their redox requirements, carbon dioxide (CO2) and methane (CH4) fluxes and water-soluble organic carbon (WSOC). Concurrently, the implications of rewetting by simulated short rainfalls (4 and 21 mm) on gaseous C fluxes were tested. Early desiccation triggered dynamic fluxes of CO2 and CH4 with peak values of 383 and 30 mg C m−2 h−1 (mean ± SD), respectively, likely in response to enhanced aerobic mineralization and accelerated evasion. At longer desiccation, CH4 dropped abruptly, likely because of reduced abundance of anaerobic microbial traits. The CO2 fluxes ceased later, suggesting aerobic activity was constrained only by extended desiccation over time. We found that rainfall boosted fluxes of CO2, which were modulated by rainfall size and the preceding desiccation time. Desiccation also reduced the amount of WSOC and the proportion of labile compounds leaching from sediment. It remains questionable to which extent changes of the sediment C pool are influenced by respiration processes, microbial C uptake and cell lysis due to drying-rewetting cycles. We highlight that the severity of the dry period, which is controlled by its duration and the presence of precipitation events, needs detailed consideration to estimate the impact of intermittent flow on global riverine C fluxes.

scholarly journals Size-Segregated Atmospheric Humic-Like Substances (HULIS) in Shanghai: Abundance, Seasonal Variation, and Source Identification

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 526
Author(s):  
Tianming Sun ◽  
Rui Li ◽  
Ya Meng ◽  
Yu Han ◽  
Hanyun Cheng ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Size Distribution ◽  
Principal Component ◽  
Water Soluble ◽  
Atmospheric Particulate Matter ◽  
Biomass Combustion ◽  
Vehicle Exhaust ◽  
Total Suspended Particulates ◽  
Condensation Mode ◽  
Water Soluble Organic Carbon

Humic-like substances (HULIS) are of great interest due to their optical and chemical characteristics. In this study, a total of 180 samples of atmospheric particulate matter (PM) of different sizes were collected from summer 2018 to spring 2019, in order to analyze the size distribution, to investigate the seasonal variation and then to identify the key sources of HULIS. The annual mean concentration of HULIS in the total suspended particulates reached 5.12 ± 1.42 μg/m3. The HULIS concentration was extremely higher in winter (8.35 ± 2.06 μg/m3) than in autumn (4.88 ± 0.95 μg/m3), in summer (3.62 ± 1.68 μg/m3) and in spring (3.36 ± 0.99 μg/m3). The average annual ratio of water-soluble organic carbon (WSOC) to OC and the ratio of HULIS to WSOC reached 0.546 ± 0.092 and 0.56 ± 0.06, respectively. Throughout the whole year, the size distributions of WSOC and HULIS-C were relatively smooth. The peaks of WSOC appeared at 1.8~3.2 μm and 0.56~1.0 μm, while the peaks of HULIS-C were located at 3.2~5.6 μm, 1.0~1.8 μm and 0.18~0.32 μm. The distribution of the HULIS particle mode was similar in spring, summer and autumn, while there was a lower proportion of the coarse mode and a higher proportion of the condensation mode in winter. By using the comprehensive analysis of principal component analysis (PCA), air mass backward trajectories (AMBTs) and fire point maps, key sources of WSOC and HULIS in Shanghai were identified as biomass combustion (48.42%), coal combustion (17.49%), secondary formation (16.07%) and vehicle exhaust (5.37%). The remaining part might be contributed by crustal dust sources, marine sources and/or other possible sources. This study provides new insight into the characteristics and size distribution of HULIS in Shanghai, thereby providing a practical base for further modeling.

scholarly journals The undetected loss of aged carbon from boreal mineral soils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Geert Hensgens ◽  
Hjalmar Laudon ◽  
Mark S. Johnson ◽  
Martin Berggren
Keyword(s):  
Organic Carbon ◽  
Boreal Forest ◽  
Soil C ◽  
Earth Systems ◽  
Nuclear Bomb ◽  
C Cycle ◽  
Water Extractable Organic Carbon ◽  
High Lability ◽  
Mineral Soils ◽  
Terrestrial Biomes

AbstractThe boreal forest is among the largest terrestrial biomes on earth, storing more carbon (C) than the atmosphere. Due to rapid climatic warming and enhanced human development, the boreal region may have begun transitioning from a net C sink to a net source. This raises serious concern that old biogenic soil C can be re-introduced into the modern C cycle in near future. Combining bio-decay experiments, mixing models and the Keeling plot method, we discovered a distinct old pre-bomb organic carbon fraction with high biodegradation rate. In total, 34 ± 12% of water-extractable organic carbon (WEOC) in podzols, one of the dominating boreal soil types, consisted of aged (~ 1000 year) labile C. The omission of this aged (i.e., Δ14C depleted) WEOC fraction in earlier studies is due to the co-occurrence with Δ14C enriched modern C formed following 1950s nuclear bomb testing masking its existence. High lability of aged soil WEOC and masking effects of modern Δ14C enriched C suggests that the risk for mobilization and re-introduction of this ancient C pool into the modern C cycle has gone undetected. Our findings have important implications for earth systems models in terms of climate-carbon feedbacks and the future C balance of the boreal forest.

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