柠条（ Caragana korshinskii ）固沙林恢复过程中表层土壤有机碳累积特征及其驱动机制

doi:10.7522/j.issn.1000-694X.2026.00077

摘要/Abstract

摘要：

植被恢复是提升荒漠化地区土壤碳汇功能的重要途径，但其土壤有机碳（SOC）积累过程及驱动机制尚不明确。以毛乌素沙地西南缘不同恢复年限（0、15、28、54、70年）人工柠条（Caragana korshinskii）固沙林为对象，系统分析植被恢复过程中凋落物蓄积、土壤理化性质、生态化学计量特征及SOC储量的变化规律，并结合多元回归和偏最小二乘路径模型（PLS-PM）解析SOC储量形成机制。结果表明：随着植被恢复，凋落物蓄积量、土壤含水量、pH值、全氮（TN）含量显著提高（P<0.05），其中凋落物蓄积量和土壤含水量增幅最大；土壤全磷（TP）含量呈先升后降趋势，并在第28年达到峰值。SOC含量和储量均随恢复年限显著增加（P<0.05），第70年分别较流沙阶段提高14.56倍和14.97倍。SOC储量积累速率呈单峰型变化趋势，在第54年达到最大值（0.0061 kg·m^-2·a^-1）。土壤化学计量比随植被恢复显著增加（P<0.05）。线性回归表明，凋落物蓄积量、土壤含水量、pH值、TN及化学计量比与SOC储量显著正相关（P<0.05）。多元回归结果显示，土壤化学计量特征、TN和凋落物蓄积量分别解释SOC储量变异的30.06%、27.09%和13.64%，其中C∶N、C∶P和N∶P化学计量比是影响土壤有机碳积累的重要预测因子。PLS-PM进一步表明，植被恢复通过直接提高TN含量，并通过TN与凋落物协同调控土壤化学计量特征，间接促进SOC储量积累。固沙植被恢复显著增强沙地生态系统土壤碳汇能力，SOC积累具有明显阶段性特征，其形成受养分累积与化学计量调控共同驱动。

关键词: 植被恢复, 土壤有机碳储量, 生态化学计量, 柠条（Caragana korshinskii）灌丛, 毛乌素沙地

Abstract:

Vegetation restoration is a critical strategy for enhancing soil carbon sequestration in desertified regions； however， the patterns of soil organic carbon （SOC） accumulation and their underlying driving mechanisms remain insufficiently understood. In this study， a restoration chronosequence （0， 15， 28， 54， and 70 years） of artificial Caragana korshinskii sand-fixing shrublands on the southwestern margin of the Mu Us Sandy Land was selected using a space-for-time substitution approach. We systematically investigated the dynamics of litter accumulation， soil physicochemical properties， ecological stoichiometric characteristics， and SOC storage along the restoration gradient. Multiple linear regression and partial least squares path modeling （PLS-PM） were employed to elucidate the mechanisms driving SOC accumulation during vegetation restoration. The results showed that litter accumulation， soil moisture content （SMC）， pH， and total nitrogen （TN） increased significantly with restoration age （P < 0.05）. Among these variables， litter accumulation and SMC exhibited the largest increases， reaching levels 6.12-fold and 17.92-fold higher， respectively， in the 70-year restoration stage than in the active sand dune （0-year） stage. Soil total phosphorus （TP） exhibited a unimodal pattern， peaking at 28 years of restoration. Both SOC content and SOC storage increased significantly along the restoration chronosequence （P < 0.05）， with the 70-year stage showing 14.56-fold and 14.97-fold increases， respectively， compared with the active sand dune stage. The accumulation rate of SOC storage also followed a unimodal pattern and reached a maximum of 0.0061 kg·m^-2·yr^-1 at 54 years. Soil stoichiometric ratios （C∶N， C∶P， and N∶P） increased significantly with restoration age （P < 0.05）. Linear regression analyses revealed significant positive relationships between SOC storage and litter accumulation， SMC， pH， TN， and soil stoichiometric ratios （P<0.05）. Multiple regression analysis further indicated that the combined effects of soil C∶N， C∶P， and N∶P ratios， TN， and litter accumulation explained 30.06%， 20.09%， and 13.64% of the variation in SOC storage， respectively. PLS-PM demonstrated that vegetation restoration directly increased TN content and indirectly promoted SOC accumulation by regulating soil stoichiometric characteristics through the synergistic effects of TN and litter accumulation. In conclusion， long-term restoration of Caragana korshinskii sand-fixing vegetation substantially enhanced the soil carbon sink capacity of sandy ecosystems. SOC accumulation exhibited clear stage-specific patterns and was jointly regulated by nutrient enrichment and shifts in soil C-N-P stoichiometry. These findings provide new insights into the mechanisms of long-term carbon sequestration in arid sandy ecosystems and offer a theoretical basis for optimizing vegetation restoration and carbon management strategies in desertified regions.

Key words: vegetation restoration, soil organic carbon storage, ecological stoichiometry, Caragana korshinskii shrubland, Mu Us Sandy Land

中图分类号:

许正强, 王兴东, 万仲武, 王瑞霞, 杨学龙. 柠条（ Caragana korshinskii ）固沙林恢复过程中表层土壤有机碳累积特征及其驱动机制[J]. 中国沙漠, 2026, 46(4): 343-353.

Zhengqiang Xu, Xingdong Wang, Zhongwu Wan, Ruixia Wang, Xuelong Yang. Accumulation characteristics and driving mechanisms of topsoil organic carbon during the restoration of Caragana korshinskii sand-fixing shrublands[J]. Journal of Desert Research, 2026, 46(4): 343-353.

图/表 6

图1 研究区概况

Fig.1 Geographic location of the study area and distribution of sampling plots

图2 不同恢复年限凋落物蓄积量和土壤理化特征注：不同小写字母表示不同年限之间差异显著（P < 0.05）

Fig.2 Litter accumulation and soil physicochemical properties under different restoration years

图3 不同恢复年限土壤有机碳含量、储量及其积累速率变化特征注：不同小写字母表示不同年限之间差异显著（P < 0.05）

Fig.3 Changes in soil organic carbon content， storage and accumulation rate under different restoration years

表1 不同恢复年限土壤化学计量特征

Table 1 Soil ecological stoichiometric characteristics across different restoration year

土壤化学计量特征	恢复年限/a
土壤化学计量特征	0	15	28	54	70
土壤碳氮比C∶N	3.86±0.67^c	5.83±0.87^c	7.94±0.47^b	10.11±0.43^a	10.10±0.89^a
土壤碳磷比C∶P	2.29±0.32^c	6.06±0.47^c	9.59±1.31^b	25.72±1.14^a	29.73±2.80^a
土壤氮磷比N∶P	0.61±0.02^b	1.17±0.24^b	1.23±0.20^b	2.55±0.12^a	2.97±0.27^a

图4 土壤有机碳储量与影响因素相关性的拟合分析注：图中灰色阴影部分代表95%置信区间

Fig.4 Regression analysis of soil organic carbon storage and its influencing factors

图5 土壤有机碳储量积累的机制分析注：LA：凋落物蓄积量；TN：土壤全氮；C∶N：土壤碳氮比；C∶P：土壤碳磷比；N∶P：土壤氮磷比；RY：恢复年限；SSR：土壤化学计量比； GOF：拟合优度。*，***分别表示在P <0.05和P <0.001显著性水平下具有统计学意义。

Fig.5 Mechanistic analysis of soil organic carbon storage accumulation

参考文献 47

[1]	Lange M， Eisenhauer N， Sierra C A，et al.Plant diversity increases soil microbial activity and soil carbon storage［J］.Nature Communications，2015，6（1）：6707.
[2]	Li Y， Piao S， Chen A，et al.Local and teleconnected temperature effects of afforestation and vegetation greening in China［J］.National Science Review，2020，7（5）：897-912.
[3]	Yang H， Li X， Wang Z，et al.Carbon sequestration capacity of shifting sand dune after establishing new vegetation in the Tengger Desert，northern China［J］.Science of the Total Environment，2014，478：1-11.
[4]	Luo L， Sun T， Pan Z，et al.Rethinking organic carbon sequestration in agricultural soils from the elemental stoichiometry perspective［J］.Global Change Biology，2025，31（7）：1-16.
[5]	Rocci K S， Cleveland C C， Eastman B A，et al.Aligning theoretical and empirical representations of soil carbon-to-nitrogen stoichiometry with process-based terrestrial biogeochemistry models［J］.Soil Biology and Biochemistry，2024，189：109272.
[6]	Cao W J， Li Y Q， Chen Y，et al.Grazing exclusion is more beneficial for restoring soil organic carbon and nutrient balance than afforestation on degraded sandy land［J］.Frontiers in Plant Science，2023，14：1-12.
[7]	Xu H W， Qu Q， Li P，et al.Stocks and stoichiometry of soil organic carbon，total nitrogen，and total phosphorus after vegetation restoration in the loess hilly region，China［J］.Forests，2019，10（1）：1-15.
[8]	Wang X Y， Yao B， Yang H L，et al.Microbial drivers of soil C∶N∶P stoichiometry dynamics during ecological restoration in sandy ecosystems［J］.Applied Soil Ecology，2025，213：1-17.
[9]	Ma R T， Hu F N， Liu J F，et al.Shifts in soil nutrient concentrations and C∶N∶P stoichiometry during long-term natural vegetation restoration［J］.PeerJ，2020，8：1-16.
[10]	Yang S B， Feng C， Ma Y H，et al.Transition from N to P limited soil nutrients over time since restoration in degraded subtropical broadleaved mixed forests［J］.Forest Ecology and Management，2021，494：1-11.
[11]	Guan H L， Fan J W， Lu X K.Soil specific enzyme stoichiometry reflects nitrogen limitation of microorganisms under different types of vegetation restoration in the karst areas［J］.Applied Soil Ecology，2022，169：1-20.
[12]	Yang T， Zhang H R， Zheng C H，et al.Bacteria life-history strategies and the linkage of soil C-N-P stoichiometry to microbial resource limitation differed in karst and non-karst plantation forests in southwest China［J］.Catena，2023，231：1-18.
[13]	Rebi A， Wang G， Yang T，et al.Stoichiometric and bacterial eco-physiological insights into microbial resource availability in karst regions affected by clipping-and-burning［J］.Journal of Environmental Management，2024，370：1-18.
[14]	Du Z， Zhou R， Chen Y，et al.Effects of long-term vegetation restoration on soil aggregate and aggregate-associated nutrient stoichiometry of desertified grassland on the eastern Qinghai-Tibet Plateau［J］.Agriculture Ecosystems & Environment，2025，388：1-20.
[15]	Zang Z F， Zhang Y， Deng S J，et al.Depth-dependent effects of aggregate-associated organic，inorganic carbon，and stoichiometry on soil structural stability following farmland abandonment［J］.Catena，2025，252：1-11.
[16]	冯佳新，吴月茹，乔硕，等.毛乌素沙地沙漠化逆转过程中土壤组分及微量元素含量变化特征［J］.中国沙漠，2024，44（1）：218-227.
[17]	李家敏，朱永华，梁丽娥，巢妍，王晓寒，王超，夏必胜.基于生态系统服务和地下水脆弱性的生态安全格局构建：以毛乌素沙地为例［J］.生态学报，2026，46（4）：1931-1947.
[18]	刘涵文，郝洪剑，郑芳欣，等.毛乌素沙地不同植被类型对土壤微生物群落及生态系统多功能性的影响［J］.生态学报，2026，46（6）：3045-3061.
[19]	于双，李小伟，杨学霞，等.灵武白芨滩柠条固沙林演替过程中林下草本植物多样性特征［J］.草业科学，2024，41（9）：2084-2093.
[20]	鲍士旦.土壤农化分析［M］.北京：中国农业出版社，2000.
[21]	Li Y， Xie T， Yang H，et al.Revegetation enhances soil organic carbon mineralization and its temperature sensitivity in the Tengger Desert，North China［J］.Catena，2022，218：106541.
[22]	Zhao F， Wu Y， Yin X，et al.Toward sustainable revegetation in the Loess Plateau using coupled water and carbon management［J］.Engineering，2022，15：143-153.
[23]	Lewis S L， Wheeler C E， Mitchard E T，et al.Restoring natural forests is the best way to remove atmospheric carbon［J］.Nature，2019，568（7750）：25-28.
[24]	Bastin J F， Finegold Y， Garcia C，et al.The global tree restoration potential［J］.Science，2019，365（6448）：76-79.
[25]	Li Y， Zhang X， Wang B，et al.Revegetation promotes soil mineral-associated organic carbon sequestration and soil carbon stability in the Tengger Desert，northern China［J］.Soil Biology and Biochemistry，2023，185：109155.
[26]	Piao S， Wang X， Park T，et al.Characteristics，drivers and feedbacks of global greening［J］.Nature Reviews Earth & Environment，2020，1（1）：14-27.
[27]	Zhang Q， Hu Y， Shao M，et al.Revegetation re-carbonizes soil：patterns，mechanisms，and challenges［J］.Fundamental Research，2026，6（1）：1-17.
[28]	Wardle D A， Walker L R， Bardgett R D.Ecosystem properties and forest decline in contrasting long-term chronosequences［J］.Science，2004，305（5683）：509-513.
[29]	Manzoni S， Taylor P， Richter A，et al.Environmental and stoichiometric controls on microbial carbon‐use efficiency in soils［J］.New Phytologist，2012，196（1）：79-91.
[30]	Shi J， Deng L， Wu J，et al.Soil organic carbon increases with decreasing microbial carbon use efficiency during vegetation restoration［J］.Global Change Biology，2024，30（12）：e17616.
[31]	Sinsabaugh R L， Manzoni S， Moorhead D L，et al.Carbon use efficiency of microbial communities：stoichiometry，methodology and modelling［J］.Ecology Letters，2013，16（7）：930-939.
[32]	Zhu X， Fang X， Wang L，et al.Regulation of soil phosphorus availability and composition during forest succession in subtropics［J］.Forest Ecology and Management，2021，502：119706.
[33]	Wang H， Wang H， Crowther T W，et al.Metagenomic insights into inhibition of soil microbial carbon metabolism by phosphorus limitation during vegetation succession［J］.ISME Communications，2024，4（1）：ycae128.
[34]	Vitousek P M， Porder S， Houlton B Z，et al.Terrestrial phosphorus limitation：mechanisms，implications，and nitrogen-phosphorus interactions［J］.Ecological Applications，2010，20（1）：5-15.
[35]	Peñuelas J， Poulter B， Sardans J，et al.Human-induced nitrogen-phosphorus imbalances alter natural and managed ecosystems across the globe［J］.Nature Communications，2013，4（1）：2934.
[36]	Duan P， Wang C， Wanek W，et al.Soil microbial phosphorus limitation constrains carbon use efficiency in subtropical forests［J］.Soil Biology and Biochemistry，2025，210：109937.
[37]	Wu J， Zhao H， Chen F，et al.Reduced soil organic carbon sequestration driven by long-term nitrogen deposition-induced increases in microbial biomass carbon-to-phosphorus ratio in alpine grassland［J］.Agriculture，2025，16（1）：1-16.
[38]	Ma Z， Liang T， Fu H，et al.Long-term green manuring increases soil carbon sequestration via decreasing qCO2 caused by lower microbial phosphorus limitation in a dry land field［J］.Agriculture，Ecosystems & Environment，2024，374：109142.
[39]	Yang Y， Liu B R.Effects of planting Caragana shrubs on soil nutrients and stoichiometries in desert steppe of Northwest China［J］.Catena，2019，183：1-20.
[40]	Kang B， Huang R， Yan X，et al.Microbial lifestyles driven by C：N stoichiometric imbalance govern responses of carbon metabolism to nitrogen addition［J］.Soil Biology and Biochemistry，2026：110162.
[41]	Wang B R， Ao D， Liang C，et al.Soil stoichiometric C/N and nitrogen availability jointly shape fungal and bacterial necromass carbon accumulation across ecosystems［J］.Soil & Tillage Research，2026，258：1-17.
[42]	Cao T， Luo Y， Shi M，et al.Microbial interactions for nutrient acquisition in soil：miners，scavengers，and carriers［J］.Soil Biology and Biochemistry，2024，188：109215.
[43]	Moorhead D L， Sinsabaugh R L， Hill B H，et al.Vector analysis of ecoenzyme activities reveal constraints on coupled C，N and P dynamics［J］.Soil Biology and Biochemistry，2016，93： 1-7.
[44]	Abay P， Gong L， Luo Y，et al.Soil extracellular enzyme stoichiometry reveals the nutrient limitations in soil microbial metabolism under different carbon input manipulations［J］.Science of the Total Environment，2024，913：169793.
[45]	Wang X， Li Y， Wang L，et al.Soil extracellular enzyme stoichiometry reflects microbial metabolic limitations in different desert types of northwestern China［J］.Science of the Total Environment，2023，874： 162504.
[46]	Qiao L L， Li Y Z， Song Y H，et al.Effects of vegetation restoration on the distribution of nutrients，glomalin-related soil protein，and enzyme activity in soil aggregates on the Loess Plateau，China［J］.Forests，2019，10（9）：1-18.
[47]	Li Y Q， Cao W J， Chen Y，et al.Responses of soil carbon，nitrogen，and phosphorus stoichiometry to afforestation of severely desertified land in northern China［J］.Ecological Indicators，2025，175：1-12.