帽儿山次生林区土壤有机碳储量及地形因子的影响

在帽儿山次生林区,按坡位、坡向差异对等设置20块样地,采集1 m剖面深度范围内不同发生层土样,研究了地形因子(坡位、坡向、坡度)对土壤有机碳含量、有机碳密度的影响,并通过逐步回归分析量化各因子对土壤有机碳密度变异影响的相对重要性。结果表明,本区土壤剖面有机碳密度为8.89~31.31 kg/m2,具有较大的空间变异性。土壤有机碳的表聚特征十分明显,平均而言,A层集中了全剖面总有机碳的53.2%。坡位和坡向显著影响土壤有机碳的分布:平均而言,下坡A层有机碳密度是上坡的1.95倍,其1 m剖面有机碳密度是上坡的1.67倍;阴坡A层有机碳密度是阳坡的1.38倍,其1 m剖面有机碳密度是阳坡的1.23倍。不过,在所调查的范围内坡度对上、下坡土壤有机碳含量和密度均无显著影响。逐步回归显示,坡位是土壤有机碳数量分异的主控因子,可独立解释A层有机碳密度空间变异的61.25%和1 m剖面有机碳空间变异的64.0%。研究结果可为区域森林土壤碳储量准确估算和碳汇林立地选择提供参考。     

地形因子对思茅松人工林土壤有机碳储量的影响

[目的]以思茅松人工中龄林为研究对象,探讨不同坡向、坡度和坡位对思茅松人工林SOC储量的影响,为精确评估思茅松人工林碳储量提供科学依据。[方法]对不同坡向、坡度和坡位不同土壤层次的SOC含量、全氮、土壤密度、C:N和SOC储量进行T检验和单因素方差分析,对不同土层的SOC储量和全氮、土壤密度、C:N之间进行Pearson相关分析。[结果]思茅松人工中龄林,SOC含量、全氮和C:N随着土层加深而减少,土壤密度随着土层加深而增加。不同的坡向和坡度显著影响SOC储量大小,阳坡的SOC储量要显著高于阴坡,坡度为20 30°的SOC储量要显著低于10 20°和0 10°,坡位对SOC储量大小无显著影响。在0 100 cm土层中,随着土层深度的增加,不同立地条件的思茅松人工中龄林的SOC储量呈减小趋势,不同坡向、坡位和坡度0 20 cm土层SOC储量均显著高于其它土层。坡向和坡度显著影响0 20 cm土层的SOC储量(P0.05);坡位对各层SOC储量均无显著影响(P0.05)。0 20 cm土层中SOC储量和土壤密度呈极显著负相关,和坡向、坡度呈显著负相关关系;除2040 cm土层外,其它土层的SOC储量与全氮之间呈极显著正相关;SOC储量和坡位与C:N在任一土层均无显著相关关系。[结论]立地条件差异影响SOC储量的大小与分布,尤其是坡向和坡度的不同会造成思茅松人工中龄林SOC储量的差异。     

外源有机物与温度耦合作用对红松阔叶混交林土壤有机碳的激发效应

[目的]探讨添加不同比例外源有机物与温度对森林土壤有机碳矿化的影响,以期进一步认识二者与土壤有机碳的生态联系。[方法]将凉水国家级自然保护区红松阔叶混交林试验样地内收集的红松枯叶、椴树和枫桦枯叶(阔叶枯叶)作为外源有机物,通过实验室培养法,在恒温箱内模拟了红松枯叶和不同添加比例的阔叶枯叶在不同培养温度(25、30、35℃)和培养时间(5、10、20、35、60、90 d)的矿化过程,利用碱液吸收法测定了不同处理土壤CO_2的释放量,计算了其有机碳矿化速率和累积矿化量,分析了其对土壤有机碳的激发效应。[结果]培养温度为25、35℃时,混合添加阔叶枯叶的激发效应优于红松枯叶的激发效应。培养温度为30℃时,添加红松枯叶的激发效应优于阔叶枯叶的激发效应。3个培养温度下,添加枯叶对土壤矿化过程具有显著的促进作用(P0.05)。培养温度为30℃时,添加外源有机物对土壤有机碳的激发效应最优。[结论]红松阔叶混交林土壤有机碳的激发效应受添加外源有机物的种类、培养温度以及培养时间等许多因素的影响。     

害虫侵染对有机农业土壤有机碳分解的研究进展

本文通过对气候变化对病虫害的影响、病虫害对经济及土壤有机碳的影响研究可知:气候变暖是病虫害发生的重要驱动力,而病虫害能造成巨大的经济损失,且受侵染土壤有机碳呈显著降低趋势,但关于土壤有机碳的研究仍是科学界的一项难题,故提出用波谱法研究土壤中指示物、研究土壤有机碳的新方法     

岷江上游不同森林类型土壤有机碳含量及密度特征

本文研究了岷江上游云杉人工林、紫果冷杉人工林、岷江冷杉人工幼龄林、高山栎天然次生林4种森林类型土壤有机碳含量及密度。结果表明:4种森林类型不同土层有机碳含量和有机碳密度均差异显著,都随土层深度增加而逐渐减小,且土壤有机碳集中分布在表层土(0~20 cm)中;4种森林类型土壤有机碳含量从高到低排序为:云杉人工林(5.896 g.kg-1)紫果冷杉人工林(5.479 g.kg-1)高山栎天然次生林(5.019 g.kg-1)岷江冷杉人工幼龄林(2.245 g.kg-1);土壤有机碳密度从高到低为:云杉人工林(0.03541 kg.m-2)高山栎天然次生林(0.03134 kg.m-2)紫果冷杉人工林(0.02474 kg.m-2)岷江冷杉人工幼龄林(0.01573 kg.m-2)。说明林分起源、树种组成、植物根系、地表枯落物和人类活动等因素影响着土壤有机碳含量及碳密度。     

莽山土壤有机碳及其空间分布格局

根据标准样地取样和实验室得出的数据及莽山第二次土壤普查资料,估算莽山土壤有机碳的含量和储量。结果表明,土壤有机碳含量大小顺序为:黄棕壤>山地黄壤>红壤>紫色土。莽山土壤有机碳总储量约为3.436×106 t,各类型土壤碳储量从大到小依次为:山地黄壤>黄棕壤>红壤>紫色土>草甸土,莽山主要土壤类型有机碳平均密度为195.35 tC·hm-2。莽山不同土壤类型的有机碳平均密度从大到小依次为:草甸土>黄棕壤>山地黄壤>红壤>紫色土,空间分布在106.85~216.83 tC·hm-2范围内变动。莽山表层土壤(0~20 cm)有机碳密度差异较大,变化范围在41.74~85.67 tC·hm-2之间,面积加权平均值为75.30 tC·hm-2。莽山表层(0~20cm)土壤有机碳储量为1.493×106 t,占莽山土壤有机碳库总碳储量38.55%。     

北亚热带土地利用变化对土壤有机碳垂直分布特征及储量的影响

利用野外调查的方法,研究了北亚热带地区土地利用变化对土壤有机碳的垂直分布特征及储量的影响.研究结果表明:(1)除茶园土壤外,不同林分土壤有机碳含量均以0～10cm土层最大,随着土层深度的增加,含量总体表现为下降的趋势;茶园土壤有机碳含量在0～30cm土层范围内增加,30cm以后表现下降的趋势;(2)次生林转变成农耕地以后土壤有机碳含量平均下降21.1%,而转变成集约经营早竹林后,土壤有机碳含量平均下降近48.5%;1m深度以内,土壤有机碳平均含量由高到低的顺序为:茶园、灌木林、次生林、粗放经营毛竹林、集约经营毛竹林、马尾松林、农耕地、杉木林和早竹林;(3)土壤有机碳储量随土层深度变化的趋势和土壤有机碳含量变化趋势基本一致;次生林转变成长期经营的农耕地后,土壤有机碳储量下降22.5%,而转变成长期集约经营早竹林后土壤有机碳储量则下降51.4%9种土地利用类型中,土壤有机碳储量由高到低的顺序为:茶园、灌木林、次生林、粗放经营毛竹林、马尾松林、农耕地、集约经营毛竹林、杉木林和早竹林.     

重庆笋溪河流域土壤有机碳特征及影响因素

为了解三峡库尾地区土壤有机碳的分布特征及影响因素,基于Arc GIS水文分析模块和数字高程模型图将重庆笋溪河流域划分为6个集水区,分别采集“园、林、耕”3种土地利用方式不同土层(0～20和20～40 cm)的土壤,测定有机碳含量并估算储量,采用方差分析、相关性分析和冗余分析探究研究区土壤有机碳的空间分布特征及其与各环境因子之间的响应关系。结果表明:随土层深度增加,土壤有机碳含量和储量均呈下降趋势,不同土层土壤有机碳含量和储量存在显著差异(P<0.05)。园地、林地和耕地0～40 cm的土壤有机碳储量范围分别为16.42～76.67,15.87～74.85和26.35～81.37 t·hm^-2。在20～40 cm土层中,耕地的土壤有机碳储量显著高于园地和林地(P<0.05),表现为耕地>园地>林地。两个土层中土壤有机碳含量和储量均与土壤全氮含量呈极显著正相关(P<0.01),而与其他指标的相关性不显著(P>0.05)。各环境因子对园地、林地和耕地土壤有机碳含量和储量的总解释率分别为86.50%,88.51%和86.13%,均强烈反...     

农田营造早竹林后土壤有机碳的变化

对农田营造早竹林后不同年限土壤有机碳变化规律的研究结果表明:(1)竹林3年生时,各层次土壤有机碳含量都呈现下降的趋势,其中表土层(0～30 cm)下降幅度最大;竹林满园后,由于采取了集约经营措施,竹林土壤有机碳含量迅速回升,至9年生时,各层次土壤有机碳含量都超过了农田相应层次水平,但是12年生时竹林各层次土壤有机碳含量又呈现下降趋势.(2)土壤有机碳密度变化和土壤有机碳含量相似,竹林3年生时各层土壤有机碳密度均呈现下降趋势;6年生时,除了0～30 cm土层继续下降外,其余各层次有机碳密度都增加;至9年生时,有机碳密度都超过相应农田各层土壤有机碳的密度;12年生时,各层土壤有机碳密度都呈现下降趋势.(3)3年生竹林土壤有机碳储量下降了近22%;以后土壤有机碳储量均逐渐增加,9年生竹林,土壤有机碳储量要超过农田土壤有机碳的储量;12年生时竹林有机碳储量下降,但是依然高于农田土壤有机碳的储量.     

不同经营措施对毛竹林土壤有机碳的影响

【目的】毛竹在森林应对气候变化中发挥重要的作用,研究竹林不同经营措施的影响,进而了解植被生物量碳库及影响土壤碳库的状况。【方法】利用两因素随机区组设计,排除地形因子等影响,选取施肥和采伐留养方式2个因素,研究不同经营措施对毛竹林各土层2010—2013年土壤有机碳含量和贮量变化影响。【结果】1)不同经营措施0~10 cm层土壤有机碳含量变化最大,介于-0.52%(±0.62%)~0.75%±(0.44%)之间,其中A2B3(中等施肥弱度采伐)与A1B1(大量施肥强度采伐)土壤有机碳含量变化量差异极显著(P<0.01);2)中等施肥0~50 cm土壤有机碳贮量增量分别是大量施肥和不施肥的3.61倍和5.05倍,大量施肥和中等施肥0~10 cm层土壤有机碳贮量变化差异显著(P<0.05);3)弱度采伐0~50 cm土壤有机碳贮量增量分别是强度采伐和中度采伐的5.51倍和1.63倍,强度采伐和弱度采伐0~10 cm层土壤有机碳贮量变化差异显著(P<0.05);4)不同经营措施0~50 cm土壤有机碳贮量变化介于-15.56(±10.21)~53.15(±37.81)t C·hm-2之间,其中A2B3(中等施肥弱度采伐)与A1B1(大量施肥强度采伐)土壤有机碳贮量变化差异极显著(P<0.01);5)结合效应图得出结论,A2B3(中等施肥弱度采伐)的经营方案对0~50 cm土壤有机碳含量和贮量的积累效果最佳,而A1B1(大量施肥强度采伐)的经营方案最不利于0~50 cm土壤有机碳含量和贮量的积累。【结论】大量施肥强度采伐方式虽然可以保证竹材的大量输出,却会破坏原有的竹林生态结构,同时对土壤碳含量和贮量的影响尤为不利,从毛竹林生态系统碳汇积累角度考虑,并不是最可取的竹林经营方式。同时经营过程中,不同经营措施不仅会对土壤碳库产生影响,更会显著改变植被碳库状况,并伴随着碳排放和碳泄漏问题,这都将成为我们今后研究经营对竹林生态系统碳综合影响的各个因素和环节。     

喀斯特洼地土壤有机碳分布特征及影响因素

为揭示沉积在洼地不同位置土壤有机碳含量的分布特征和相关影响因素,以西南喀斯特典型小流域内洼地底部、落水洞不同部位土壤为研究对象,采集0~150 cm土壤剖面的土样,测定相关理化性质指标,分析土壤有机碳含量随空间位置的变化特征,并探讨土壤有机碳含量与理化性质的相关性。结果表明:落水洞、洼地底部土壤有机碳含量与土壤有机碳储量均为表层最高,呈表聚化现象;落水洞、洼地底部土壤有机碳含量与全氮含量均呈显著正相关,而与土壤含水率相关性不显著(P>0.05);落水洞土壤有机碳含量平均值大于洼地底部土壤有机碳含量平均值,土壤有机碳含量与土壤容重、总孔隙度分别呈极显著负相关、极显著正相关(P<0.01),与土壤pH值相关性不显著,表明落水洞土壤有机碳含量变化主要受土壤容重、总孔隙度等物理性质影响显著;洼地底部土壤有机碳含量变异系数大于落水洞土壤有机碳含量变异系数,土壤有机碳含量与土壤pH值呈显著的负相关关系(P<0.05),与土壤容重、总孔隙度相关性不显著,表明洼地底部土壤有机碳含量的分布特征主要受土壤pH值的影响。     

Estimation of soil organic carbon based on remote sensing and process model

The estimation of the soil organic carbon content (SOC) is one of the important issues in the research of the global carbon cycle. However, there are great differences among different scientists regarding the estimated magnitude of SOC. There are two commonly used methods for the estimation of SOC, with each method having both advantages and disadvantages. One method is the so called direct method, which is based on the samples of measured SOC and maps of soil or vegetation types. The other method is the so called indirect method, which is based on the ecosystem process model of the carbon cycle. The disadvantage of the direct method is that it mainly discloses the difference of the SOC among different soil or vegetation types. It can hardly distinguish the difference of the SOC in the same type of soil or vegetation. The indirect method, a process-based method, is based on the mechanics of carbon transfer in the ecosystem and can potentially improve the spatial resolution of the SOC estimation if the input variables have a high spatial resolution. However, due to the complexity of the process-based model, the model usually simplifies some key model parameters that have spatial heterogeneity with constants. This simplification will produce a great deal of uncertainties in the estimation of the SOC, especially on the spatial precision. In this paper, we combined the process-based model (CASA model) with the measured SOC, in which the remote sensing data (AVHRR NDIV) was incorporated into the model to enhance the spatial resolution. To model the soil base respiration, the Van’t Hoff model was used to combine with the CASA model. The results show that this method could significantly improve the spatial precision (8 km spatial resolution). The results also show that there is a relationship between soil base respiration and the SOC as the influence of environmental factors, i.e., temperature and moisture, had been removed from soil respiration which makes the SOC the most important factor of soil base respiration. The statistical model of soil base respiration and the SOC shows that the determinant coefficient (R ²) is 0.78. As the method in this paper contains advantages from both direct and indirect methods, it could significantly improve the spatial resolution and, at the same time, keep the estimation of SOC well matched with the measured SOC. __________ Translated from Journal of Remote Sensing, 2007, 11(1): 127–136 [译自: 遥感学报]     

Characteristics of soil organic carbon mineralization and influence factor analysis of natural Larix olgensis forest at different ages

Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK.     

土壤有机碳动态模型的研究进展

As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and global change. With development of mathematical models that simulate changes in soil organic carbon, there have been considerable advances in understanding soil organic carbon dynamics. This paper mainly reviewed the composition of soil organic matter and its influenced factors, and recommended some soil organic matter models worldwide. Based on the analyses of the developed results at home and abroad, it is suggested that future soil organic matter models should be developed toward based-process models, and not always empirical ones. The models are able to reveal their interaction between soil carbon systems, climate and land cover by technique and methods of GIS (Geographical Information System) and RS (Remote Sensing). These models should be developed at a global scale, in dynamically describing the spatial and temporal changes of soil organic matter cycle. Meanwhile, the further researches on models should be strengthen for providing theory basis and foundation in making policy of green house gas emission in China.     

Spatial variability of soil organic carbon in the forestlands of northeast China

Soil organic carbon(SOC) is an effective indicator of soil fertility and productivity, and it varies spatially and temporally in relation to other soil properties. Spatial variability of SOC in the forestlands of northeast China was characterized using geostatistics. Soil samples at the depths of 0?20 cm, 20?40 cm and 40?60 cm were collected from sixty-three temporary plots to evaluate SOC concentration and density(SOCD) and other soil properties. We analyzed correlations between SOC and soil properties. Soil organic carbon concentrations were high. The total amount of C stored in soil(0?60 cm) was 16.23 kg·m-2 with the highest SOCD of 7.98 kg?m-2 in topsoil. Soil properties in most cases differed by horizon, suggesting different processes and effects in each horizon. Soil organic carbon had positive relationships with total N, P and K as well as readily available K, but did not show a significant positive correlation with available P. Spatial factors including elevation, slope and aspect affected SOC distribution. Soil organic carbon at 0?60 cm had strong spatial autocorrelation with nugget/sill ratio of 5.7%, and moderate structured dependence was found at 0?20 cm, which indicated the existence of a highly developed spatial structure. Spatial distributionsof SOC concentration and SOCD were estimated using regression-kriging, with higher prediction accuracy than ordinary kriging. The fractal dimension of SOC indicated the preferential pattern of SOC distribution, with the greatest spatial heterogeneity and strongest spatial dependence in the northeast-southwest direction.     

三种人工林的土壤碳密度动态研究

对木荷、尾叶桉、湿地松3种人工l林的土壤碳密度进行研究。结果表明：不同林分的土壤碳密度存在差异,木荷、尾叶桉、湿地松林地1999年的土壤碳密度分别为181.13t／hm^2、34.21t／hm。和100.35t／hm^2,2012年的分别为237.94t／hm^2、92.03t／hm^2和144.39t／hm^2,其大小排序为木荷林地〉湿地松林地〉尾叶桉林地,其中以乡土树种木荷林地的土壤有机碳密度最高。3种林地的土壤有机碳密度均显著增加,其中尾叶桉林地的增幅最大。     

土壤微生物生物量碳研究进展综述

土壤微生物量碳是土壤碳素转化的重要环节,也是土壤有效碳库的重要组成部分。文章从土壤微生物量碳的影响因素、测定、周转以及土壤微生物量碳与土壤有机碳的关系四个方面综述了土壤微生物生物量碳的研究进展。同时,为今后这方面的研究重点及发展方向提供了参考。     

亚热带日本落叶松中、幼龄林土壤有机碳密度和分配特征

本文基于32块样地土壤数据,对亚热带日本落叶松中、幼龄林的土壤有机碳密度及其分配特征进行了分析,结果发现:(1)中龄林的有机碳含量、有机碳密度明显高于幼龄林;(2)混交林的有机碳含量、有机碳密度明显高于纯林;(3)0~80 cm的土壤有机碳密度为172.25 t/hm2。有机碳主要集中在表土层0~20 cm处,此表土层有机碳密度分别是土层20~40 cm、40~80 cm的175.21%、129.52%。在土层相同的情况下,随着土壤深度的增加,其土壤有机碳密度呈下降趋势;(4)与适宜亚热带地区生长的造林树种——杉木相比,日本落叶松林的土壤有机碳含量、土壤有机碳密度均明显高于20年生杉木人工林,说明日本落叶松林土壤的固碳能力大于杉木人工林,从侧面也反映了同样作为亚热带地区的造林树种,日本落叶松林要优于杉木人工林。     

白桦天然次生林土壤有机碳的空间分布特征

为了了解冀北地区白桦天然次生林土壤有机碳的分布特征,以承德市围场县、丰宁县和张家口赤城县白桦天然次生林为研究对象,对其土壤有机碳含量进行了测定分析。结果表明:4个地区的白桦天然次生林各层土壤有机碳含量由高到低顺序依次为赤城县黑龙山、围场县孟滦、丰宁县四岔口、围场县燕格柏,其0~10cm的土壤有机碳含量依次为108.07g/kg、65.61g/kg、52.33g/kg和30.04g/kg;土壤有机碳含量有随海拔升高而上升的趋势;各地区白桦天然次生林的土壤有机碳含量都以表层最高,随着土层深度的增加,土壤有机碳含量呈现逐渐降低的趋势,且随深度的增加,土壤碳含量下降速度逐渐趋缓。     

磷添加对南亚热带森林土壤有机碳氮矿化影响的培养实验研究

采用室内培养的方法,分析了磷添加对南亚热带鼎湖山马尾松林（PMF）、针阔叶混交林（PBMF）和季风常绿阔叶林（MEBF）土壤（0～10cm）CO小CH4排放／吸收和有机氮矿化的影响。结果表明：28周的培养,100mg磷添加处理土壤C—CO2累积排放量依次为PMF、PBMF和MEBF对照的82．4％、84．4％和102．8％,2000mg磷处理土壤依次为其对照的107．2％、101．2％和109．1％;100mg磷处理土壤CH4累积排放量依次为其对照的69．9％、102．7％和66．3％,2000mg磷处理土壤依次为其对照的-57．4％、25．3％和22．4％,其中,磷在处理初期较一致的提高土壤CO2和CH4排放,磷对土壤有机碳矿化的影响与森林的土壤状况有关,添加的磷浓度越高,其促进作用越强。1周的培养,100mg磷处理土壤有效氮净矿化量依次比PMF、PBMF和MEBF对照少37．06％、39．60％和28．62％,2000mg磷处理土壤依次比其对照少70．97％、84．14％和187．97％,100mg磷处理土壤硝态氮净矿化量依次比其对照少48．06％、40．45％和28．03％,2000mg磷处理土壤依次比其对照少254．09％、115．32％和238．50％,磷显著的抑制土壤有机氮的矿化和硝化。结果建议,在研究P对土壤有机碳氮矿化过程时应充分考虑土壤对P的吸附作用。