Background As commonly used harvest residue management practices in subtropical plantations,stem only harvesting(SOH)and whole tree harvesting(WTH)are expected to affect soil organic carbon(SOC)***,knowledge on how SO...
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Background As commonly used harvest residue management practices in subtropical plantations,stem only harvesting(SOH)and whole tree harvesting(WTH)are expected to affect soil organic carbon(SOC)***,knowledge on how SOC and its fractions(POC:particulate organic carbon;MAOC:mineral-associated organic carbon)respond to different harvest residue managements is *** In this study,a randomized block experiment containing SOH and WTH was conducted in a Chinese fir(Cunninghamia lanceolata)*** effect of harvest residue management on SOC and its fractions in topsoil(0–10cm)and subsoil(20–40cm)was *** inputs(harvest residue retaining mass and fine root biomass)and microbial and mineral properties were also *** The responses of SOC and its fractions to different harvest residue managements varied with soil ***,SOH enhanced the content of SOC and POC in topsoil with increases of 15.9%and 29.8%,respectively,compared with ***,SOH had no significant effects on MAOC in topsoil and SOC and its fractions in *** results indicated that the increase in POC induced by the retention of harvest residue was the primary contributor to SOC accumulation,especially in *** harvest residue managements affected SOC and its fractions through different pathways in topsoil and *** plant inputs(the increase in fine root biomass induced by SOH)exerted a principal role in the SOC accumulation in topsoil,whereas mineral and microbial properties played a more important role in regulating SOC dynamics than plants inputs in *** The retention of harvest residues can promote SOC accumulation by increasing POC,and is thus suggested as an effective technology to enhance the soil carbon sink for mitigating climate change in plantation management.
Priming effect(PE)on soil organic carbon(SOC)decomposition caused by the addition of organic carbon(C)is an important ecological process in regulating soil C ***,most priming studies are confined to laboratory trials,...
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Priming effect(PE)on soil organic carbon(SOC)decomposition caused by the addition of organic carbon(C)is an important ecological process in regulating soil C ***,most priming studies are confined to laboratory trials,while the assessment of soil PE under field conditions with variable weather conditions is *** study assessed the direct effects of glucose addition and in-situ warming on the extent of PE under field conditions in a temperate *** evaluated soil PE using 13C-glucose labelling,a simple and novel technique,based on the Keeling plot *** addition significantly enhanced native SOC decomposition and induced strong ***,the effect of in-situ warming on the extent of PE was not *** study confirms the importance of PE in regulating SOC turnover under field conditions.
Background:Despite the crucial role of nitrogen(N)availability in carbon(C)cycling in terrestrial ecosystems,soil organic C(SOC)mineralization in different sizes of soil aggregates under various land use types and the...
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Background:Despite the crucial role of nitrogen(N)availability in carbon(C)cycling in terrestrial ecosystems,soil organic C(SOC)mineralization in different sizes of soil aggregates under various land use types and their responses to N addition is not well *** investigate the responses of soil C mineralization in different sized aggregates and land use types to N addition,an incubation experiment was conducted with three aggregate-size classes(2000,250,and 53μm)and two land use types(a Chinese fir plantation and a paddy land).Results:Cumulative C mineralization of the<53-μm fractions was the highest and that of microaggregates was the lowest in both forest and paddy soils,indicating that soil aggregates enhanced soil C stability and reduced the loss of soil *** C mineralization in all sizes of aggregates treated with N addition decreased in forest soils,but that in microaggregates and the<53-μm fraction increased in paddy soils treated with 100μgNg−***,the effect sizes of N addition on C mineralization of forest soils were below zero,but those of paddy soils were above *** data indicated that N addition decreased SOC mineralization of forest soils but increased that of paddy ***:Soil aggregates play an important role in soil C sequestration,and decrease soil C loss through the increase of soil C stability,regardless of land use types.N addition has different effects on soil C mineralization in different land use *** results highlight the importance of soil aggregates and land use types in the effects of N deposition on the global terrestrial ecosystem C cycle.
Phenolic acids are secondary metabolites of plants that significantly affect nutrient cycling *** investigate such effects,the soil available nitrogen(N)content,phenolic acid content,and net N mineralization rate in t...
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Phenolic acids are secondary metabolites of plants that significantly affect nutrient cycling *** investigate such effects,the soil available nitrogen(N)content,phenolic acid content,and net N mineralization rate in three successive rotations of Chinese fir plantations in subtropical China were *** N mineralization and nitrification rates in soils treated with phenolic acids were measured in an ex situ *** with first-rotation plantations(FCP),the contents of total soil nitrogen and nitrate in second(SCP)-and third-rotation plantations(TCP)decreased,and that of soil ammonium *** net N mineralization rates in the second-and third-rotation plantations also increased by 17.8%and 39.9%,*** contrast,soil net nitrification rates decreased by 18.0%and 25.0%,*** concentrations of total phenolic acids in the FCP soils(123.22±6.02 nmol g^-1)were 3.0%and 17.9%higher than in the SCP(119.68±11.69 nmol g^-1)and TCP(104.51±8.57 nmol g^-1,respectively).The total content of phenolic acids was significantly correlated with the rates of net soil N mineralization and net *** ex situ experiment showed that the net N mineralization rates in soils treated with high(HCPA,0.07 mg N kg^-1 day^-1)and low(LCPA,0.18 mg N kg^-1 day^-1)concentrations of phenolic acids significantly decreased by 78.6%and 42.6%,respectively,comparing with that in control(0.32 mg N kg^-1 day^-1).Soil net nitrification rates under HCPA and LCPA were significantly higher than that of the *** results suggested that low contents of phenolic acids in soil over successive rotations increased soil net N mineralization rates and decreased net nitrification rates,leading to consequent reductions in the nitrate content and enhancement of the ammonium content,then resulting in enhancing the conservation of soil N of successive rotations in Chinese fir plantation.
Although previous studies have shown that the patterns of soil microbial communities are significantly associated with plant traits in natural ecosystems, evidence from plantation ecosystems is scarce. Furthermore, th...
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