Factors controlling Carex brevicuspis leaf litter decomposition and its contribution to surface soil organic carbon pool at different water levels

Abstract. Litter decomposition plays a vital role in wetland carbon cycling. However, the contribution of aboveground litter decomposition to the wetland soil organic carbon (SOC) pool has not yet been quantified. Here, we conducted a Carex brevicuspis leaf litter input experiment to clarify the intrinsic factors controlling litter decomposition and quantify it's contribution to SOC pool at different water levels. This species is ubiquitous to global freshwater wetlands. We sampled this plant leaf litter at −25, 0, and +25 cm relative to the soil surface over 280 days and analysed leaf litter decomposition and its contribution to the SOC pool. The mass loss and carbon release rates were the highest at +25 cm water level, followed by the 0 cm water level. The rates of these parameters were the lowest at −25 cm water level. Significant amounts of litter carbon, nitrogen, and phosphorus were released at all three water levels. Litter input significantly increased the soil microbial biomass and fungal density but had nonsignificant impacts on soil bacteria, actinomycetes, and fungal/bacterial concentrations at all three water levels. Compared with litter removal, litter application increased the SOC by 25.12 %, 9.58 %, and 4.98 % at the +25 cm, 0 cm, and −25 cm water levels, respectively. Hence, higher water levels facilitate the release of organic carbon from leaf litter into the soil via water leaching. In this way, they strengthen the soil carbon pool. At lower water levels, soil carbon is lost as the slower litter decomposition rate and active microbial (actinomycete) respiration. Our results revealed that the water level in natural wetlands influences litter decomposition mainly by leaching and microbial activity, by extension, affects wetland surface carbon pool.

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Factors controlling Carex brevicuspis leaf litter decomposition and its contribution to surface soil organic carbon pool at different water levels

Biogeosciences ◽

10.5194/bg-18-1-2021 ◽

2021 ◽

Vol 18 (1) ◽

pp. 1-11

Author(s):

Lianlian Zhu ◽

Zhengmiao Deng ◽

Yonghong Xie ◽

Xu Li ◽

Feng Li ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Water Level ◽

Leaf Litter ◽

Litter Decomposition ◽

Decomposition Rate ◽

Dry Weight ◽

Water Levels ◽

Carbon Pool ◽

Litter Input

Abstract. Litter decomposition plays a vital role in wetland carbon cycling. However, the contribution of aboveground litter decomposition to the wetland soil organic carbon (SOC) pool has not yet been quantified. Here, we conducted a Carex brevicuspis leaf litter input experiment to clarify the intrinsic factors controlling litter decomposition and quantify its contribution to the SOC pool at different water levels. The Carex genus is ubiquitous in global freshwater wetlands. We sampled this plant leaf litter at −25, 0, and +25 cm relative to the soil surface over 280 d and analysed leaf litter decomposition and its contribution to the SOC pool. The percentage litter dry weight loss and the instantaneous litter dry weight decomposition rate were the highest at +25 cm water level (61.8 %, 0.01307 d−1), followed by the 0 cm water level (49.8 %, 0.00908 d−1), and the lowest at −25 cm water level (32.4 %, 0.00527 d−1). Significant amounts of litter carbon, nitrogen, and phosphorus were released at all three water levels. Litter input significantly increased the soil microbial biomass and fungal density but had nonsignificant impacts on soil bacteria, actinomycetes, and the fungal∕bacterial concentrations at all three water levels. Compared with litter removal, litter addition increased the SOC by 16.93 %, 9.44 %, and 2.51 % at the +25, 0, and −25 cm water levels, respectively. Hence, higher water levels facilitate the release of organic carbon from leaf litter into the soil via water leaching. In this way, they increase the soil carbon pool. At lower water levels, soil carbon is lost due to the slower litter decomposition rate and active microbial (actinomycete) respiration. Our results revealed that the water level in natural wetlands influenced litter decomposition mainly by leaching and microbial activity, by extension, and affected the wetland surface carbon pool.

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Carbon storage in cotton soils of northern New South Wales

Soil Research ◽

10.1071/sr02023 ◽

2003 ◽

Vol 41 (5) ◽

pp. 889 ◽

Cited By ~ 29

Author(s):

T. A. Knowles ◽

B. Singh

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Content ◽

Soil Carbon ◽

Inorganic Carbon ◽

Carbon Pool ◽

Total Carbon ◽

Soil Types ◽

Soil Carbon Pool ◽

Total Soil

Soil carbon is an important component of the global carbon cycle with an estimated pool of soil organic carbon of about 1500 Gt. There are few estimates of the pool of inorganic carbon, but it is thought to be approximately 50% of the organic carbon pool. There is no detailed study on the estimation of the soil carbon pool for Australian soils.In order to quantify the carbon pools and to determine the extent of spatial variability in the organic and inorganic carbon pools, 120 soil cores were taken down to a depth of 0.90 m from a typical cotton field in northern NSW. Three cores were also taken from nearby virgin bushland and these samples were used as paired samples. Each soil core was separated into 4 samples, i.e. 0–0.15, 0.15–0.30, 0.30–0.60, and 0.60–0.90 m. Soil organic carbon was determined by wet oxidation and inorganic carbon content was determined using the difference between total carbon and organic carbon, and confirmed by the acid dissolution method. Total carbon was measured using a LECO CHN analyser. Soil organic carbon of the field constituted 62% (0–0.15 m), 58% (0.15–0.30 m), 60% (0.30–0.60 m), and 67% (0.60–0.90 m) of the total soil carbon. The proportion of inorganic carbon in total carbon is higher than the global average of 32%. Organic carbon content was relatively higher in the deeper layers (>0.30�m) of the studied soils (Vertosols) compared with other soil types of Australia. The carbon content varied across the field, however, there was little correlation between the soil types (grey, red, or intergrade colour) and carbon content. The total soil carbon pool of the studied field was estimated to be about 78 t/ha for 0–0.90 m layer, which was approximately 58% of the total soil carbon in the soil under nearby remnant bushland (136 t/ha). The total pool of carbon in the cotton soils of NSW was estimated to be 44.8 Mt C, where organic carbon and inorganic carbon constitute 34.9 Mt C and 9.9 Mt C, respectively. Based on the results of a limited number of paired sites under remnant vegetation, it was estimated that about 18.9 Mt of C has been lost from Vertosols by cotton cropping in NSW. With more sustainable management practices such as conservation tillage and green manuring, some of the lost carbon can be resequestered, which will help to mitigate the greenhouse effect, improve soil quality and may increase crop yield.

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Organic Carbon Accumulation in Topsoil Following Afforestation with Willow: Emphasis on Leaf Litter Decomposition and Soil Organic Matter Quality

Forests ◽

10.3390/f6030769 ◽

2015 ◽

Vol 6 (12) ◽

pp. 769-793 ◽

Cited By ~ 4

Author(s):

Benoit Lafleur ◽

Michel Labrecque ◽

Alexandre Arnold ◽

Nicolas Bélanger

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Carbon ◽

Leaf Litter ◽

Litter Decomposition ◽

Carbon Accumulation ◽

Leaf Litter Decomposition ◽

Organic Matter Quality ◽

Soil Organic Matter Quality

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Increased litter input increases litter decomposition and soil respiration but has minor effects on soil organic carbon in subtropical forests

Plant and Soil ◽

10.1007/s11104-015-2450-4 ◽

2015 ◽

Vol 392 (1-2) ◽

pp. 139-153 ◽

Cited By ~ 37

Author(s):

Xiong Fang ◽

Liang Zhao ◽

Guoyi Zhou ◽

Wenjuan Huang ◽

Juxiu Liu

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Respiration ◽

Litter Decomposition ◽

Subtropical Forests ◽

Litter Input

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Relative Contribution of aggregated soil Carbon to soil organic carbon pool in an Ultisol, SouthEastern Nigeria

10.5194/egusphere-egu2020-6761 ◽

2020 ◽

Author(s):

Akudo Ogechukwu Onunwa ◽

Ifeyinwa Monica Uzoh ◽

Chukwuebuka Christopher Okolo ◽

Charles Arinze Igwe ◽

John Nwite

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Carbon ◽

Organic Amendments ◽

Aggregate Size ◽

Cropping System ◽

Carbon Pool ◽

Relative Contribution ◽

Split Plot ◽

Organic Carbon Pool

&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; ABSTRACTMaintenance of Soil Organic Matter (SOM) has been recognized as a strategy that could reduce soil degradation, improve soil organic carbon (SOC) pool thereby reducing atmospheric concentration of carbon iv oxide (CO2) so as to ameliorate the effect of carbon and other greenhouse gases on the environment. Soil fertility depletion in the humid tropics is a serious problem emanating from erosion and leaching due to intense rainfall. Decrease in soil fertility and productivity is believed to be due to depletion in SOM. This study aims at determining the relative contributions (RC) of the various aggregated soil carbon (CWSA) (which is a function of available organic matter in the soil) to Soil organic carbon pool. Soil samples were collected from an area of land (0.1125ha) planted to sole cowpea, sole maize and maize-cowpea intercrop in No till (NT) and conventionally tilled (CT) plots amended with poultry droppings (PD), pig waste (PW), cassava peels (CP) at 20t/ha each and a control in a split-split plot in Randomized Complete Block Design with three replicates. Cropping system was assigned to the main plots, tillage system was assigned to split plot while organic amendments and control was assigned to the split-split plot measuring 7.5m2. The same treatment was maintained for two planting seasons (2012 and 2013), with the residual taken in 2013. Soil samples were collected at 0-30cm at the end of each planting season and SOC of the whole soil and the aggregated&#160; soil carbon (2mm, 2-1mm,1-0.5mm 0.5-0.25mm and < 0.25mm) were determined using Walkley&#160; and Black method as described by Nelson and Sommers (1982). Data collected were subjected to Analysis of Variance (ANOVA) using Genstat release 7.22D. The result revealed that there is a trend of aggregate size fractions 1-0.25mm contributing more carbon to the SOC than aggregate size fractions >2-1mm irrespective of the cropping system, tillage method or organic amendments applied. The highest relative contribution of aggregated soil carbon to the SOC pool shifted from the micro-aggregates (<0.25mm) to the macro-aggregates (1.0-0.25mm) for as long as the organic amendments lasted but gradually returned to the micro-aggregates when the amendments were withdrawn. It is therefore recommended that organic amendments be use to improve the soil aggregation which goes a long way in improving soil carbon pool thereby ameliorating the effect of carbon and other green house gases on the environment.Key Words: Soil Organic carbon pool, Soil Aggregated carbon, Relative Contribution, Macro and Micro Aggregates

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