湖南衡陽(yáng)紫色土丘陵坡地植被恢復(fù)對(duì)土壤有機(jī)碳及全氮的影響

桂德志, 曠一明, 張衛(wèi)國(guó), 文東新

(1.祁陽(yáng)縣掛榜山林場(chǎng)，湖南 祁陽(yáng) 426100；2.中南林業(yè)科技大學(xué)理學(xué)院，湖南 長(zhǎng)沙 410004)

湖南衡陽(yáng)紫色土丘陵坡地植被恢復(fù)對(duì)土壤有機(jī)碳及全氮的影響

桂德志1, 曠一明1, 張衛(wèi)國(guó)1, 文東新2

(1.祁陽(yáng)縣掛榜山林場(chǎng)，湖南 祁陽(yáng) 426100；2.中南林業(yè)科技大學(xué)理學(xué)院，湖南 長(zhǎng)沙 410004)

采用“空間序列代替時(shí)間序列”的方法，將植被恢復(fù)階段劃分為演替前期、演替中期和演替后期，并測(cè)定每一演替階段中0～10，10～20，20～30，30～40 cm土層的土壤有機(jī)碳與全氮.結(jié)果表明：1)隨著演替進(jìn)行，各土層的土壤有機(jī)碳與全氮均顯著增加(P<0.05)，具體表現(xiàn)為后期(土壤有機(jī)碳,全氮)>中期(土壤有機(jī)碳,全氮)>前期(土壤有機(jī)碳,全氮)；2)隨著土層深度的增加，土壤有機(jī)碳與全氮均顯著減小(P<0.05)，具體表現(xiàn)為0～10 cm土層(土壤有機(jī)碳,全氮)>10～20 cm土層(土壤有機(jī)碳,全氮)>20～30 cm土層(土壤有機(jī)碳,全氮)>30～40 cm土層(土壤有機(jī)碳,全氮).圖1，表3，參29.

土壤有機(jī)碳；全氮；植被恢復(fù)；衡陽(yáng)

土地系統(tǒng)與植被是一個(gè)有機(jī)整體，二者相輔相成、相互影響.土壤系統(tǒng)為植物生長(zhǎng)提供必須的營(yíng)養(yǎng)物質(zhì)，而植被生長(zhǎng)又可改善土壤系統(tǒng)的結(jié)構(gòu)和養(yǎng)分.在土壤系統(tǒng)中，土壤微生物作為土壤有機(jī)質(zhì)和養(yǎng)分(N、P、S等)轉(zhuǎn)化和循環(huán)的動(dòng)力，參與有機(jī)質(zhì)的分解、腐殖質(zhì)的形成、養(yǎng)分的轉(zhuǎn)化和循環(huán)等生化過(guò)程，在土壤生態(tài)系統(tǒng)的能量流動(dòng)和養(yǎng)分轉(zhuǎn)化起著重要作用[1-2].陸地生態(tài)系統(tǒng)是一個(gè)巨大的C庫(kù)，約含2500 PgC，近90%的C儲(chǔ)存在土壤生態(tài)系統(tǒng)中，且分解緩慢.植被恢復(fù)是土壤有機(jī)碳(Soil organic carbon,SOC)與全氮(Total nitrogen,TN)改變的重要影響因素[3-4]，一方面，植被恢復(fù)提高了土壤的C與N素歸還量；另一方面，植被恢復(fù)可改善土壤理化性質(zhì)，加速土壤呼吸作用，而造成SOC與TN的損失[5-6].因此，探討植被恢復(fù)與SOC、TN的關(guān)系，對(duì)于C與N貯存的研究具有重大意義.

衡陽(yáng)紫色土丘陵坡地面積1.625×105hm2，占據(jù)衡陽(yáng)市總國(guó)土面積的25%.它是中國(guó)南方獨(dú)有的土地類型，這類土地以其土壤特別的色澤、優(yōu)良的自然肥力等成為中國(guó)一種特有的、具有發(fā)展農(nóng)業(yè)優(yōu)勢(shì)的寶貴土地資源.但是紫色土丘陵坡地生態(tài)問(wèn)題和本身的生產(chǎn)性問(wèn)題特別突出.紫色土丘陵坡地生態(tài)環(huán)境脆弱，氣候干旱，水土流失嚴(yán)重；紫色土耐旱性差，土壤養(yǎng)分含量不協(xié)調(diào)，紫色土本身不耐侵蝕.在植被遭到破壞后，紫色土丘陵坡地表土很快被流失，土地大量荒蕪，恢復(fù)林草植被十分困難，農(nóng)林牧生產(chǎn)受到很大制約(圖1).長(zhǎng)期以來(lái)，該區(qū)域區(qū)域?qū)嵤┲脖换謴?fù)及退耕還林、還草政策取得了良好的水土保持效果，但以往對(duì)水土保持效果的研究多集中于土壤水分、植被等方面的研究[7-8].而對(duì)不同恢復(fù)階段SOC與TN的變化的研究相對(duì)薄弱，由于不同植被的生長(zhǎng)方式不同，對(duì)土壤生態(tài)系統(tǒng)的影響存在差異，且在植被恢復(fù)過(guò)程中的不同階段，土壤生態(tài)系統(tǒng)的變化也不盡相同.為此，研究采用時(shí)空互代的方法[9-10]，研究衡陽(yáng)紫色土丘陵坡地植被恢復(fù)對(duì)SOC與TN的影響，旨在該區(qū)域的植被恢復(fù)提供科學(xué)依據(jù).

1 試驗(yàn)方法

1.1 樣地的選擇與取樣方法

2009年8月中旬，按群落演替的順序選擇坡度(向、位、形)和裸巖率等生態(tài)因子基本一致的植物群落，它們分別處于演替前期、演替中期和演替后期.在3個(gè)不同的演替階段按樣線法采用固定間距分別設(shè)置15個(gè)20 cm×50 cm的樣方，共45個(gè)樣方，測(cè)定每個(gè)樣方內(nèi)0～10、10～20、20～30與30～40 cm土層的SOC和TN的含量.樣地基本概況見(jiàn)表1.

圖1 研究區(qū)域土壤概況Fig.1 Status of soils in the studied area

表1 樣地概況
Tab.1 General situation of sampling plots

項(xiàng)目前期中期后期海拔/m120127118經(jīng)度/N26°12'45″26°13'41″26°32'57″緯度/E112°30'45″111°54'27″112°54'08″坡向SW26SW25SW27坡度/°243219演替年限/a4～520～30≈50蓋度/%214569

1.2 測(cè)定方法

SOC采用重鉻酸鉀氧化—外加熱法測(cè)定；TN采用半微量凱氏法測(cè)定[11-12].

1.3 數(shù)據(jù)處理

采用Excel軟件處理基礎(chǔ)數(shù)據(jù)，采用單因素方差分析法(one-way ANOVA)和最小顯著差異法(LSD)分析不同演替階段與不同土層之間的差異顯著性(P<0.05).表中所有數(shù)據(jù)均為3次重復(fù)的平均值.

2 結(jié)果與分析

2.1 植被恢復(fù)對(duì)SOC的影響

研究表明(表2)，在0～10、10～20、20～30與30～40 cm土層，隨著演替的進(jìn)行，SOC均顯著增加(P<0.05)，0～10 cm土層，前期SOC含量分別為中期與后期的92.64%和73.58%；10～20 cm土層，91.12%和75.18%；20～30 cm土層，76.10%和62.78%；30～40 cm土層，76.82%和72.51%.在演替前期、中期與后期，0～10 cm土層的SOC含量顯著高于其他土層SOC含量(P<0.05)，前期，0～10 cm土層的SOC含量分別為10～20、20～30與30～40 cm土層的1.14、1.53和1.54倍；中期，1.12、1.26和1.28倍；后期，1.17、1.31和1.52倍.

表2 不同演替階段土壤有機(jī)碳含量的變化Tab.2 The changes of soil organic carbon at different successive stages(g.kg-1)

注：同行不同大寫(xiě)字母表示不同演替之間差異顯著(P<0.05)，同列不同小寫(xiě)字母表示不同土層之間差異顯著(P<0.05).下同.

2.2 植被恢復(fù)對(duì)TN的影響

從表3可知，在衡陽(yáng)紫色土丘陵坡地，隨著演替進(jìn)行，TN顯著增加(P<0.05)；隨土層加深，TN含量顯著減小(P<0.05).0～10 cm土層，后期TN含量分別為前期和中期的1.28和1.18倍；10～20 cm土層，1.33和1.26倍；20～30 cm土層，1.30和1.20倍；30～40 cm土層，1.17和1.05倍.演替前期，10～20、20～30與30～40 cm土層TN含量分別為0～10 cm土層的84.50%、75.50%和71.50%；中期，82.03%、75.58和73.27%；后期，87.50%、76.56和65.23%.

表3 不同演替階段土壤全氮含量的變化Tab.3 The changes of soil total nitrogen at different successive stages(g.kg-1)

3 討論與結(jié)論

3.1 討論

在演替前期，土壤裸露率高，水土流失嚴(yán)重，土壤水分蒸發(fā)量大，土壤含水量低[13]，植物枯枝落葉少，土壤微生物數(shù)量少，土壤基礎(chǔ)呼吸弱，土壤的生化強(qiáng)度與酶活性低，影響土壤理化性質(zhì)的改善，導(dǎo)致該階段SOC與TN少[14-17]，該研究結(jié)果與高永恒等[18]高山草甸的C、N格局的研究結(jié)果基本一致，Schuman等[19]在研究不同恢復(fù)年限各土層SOC、TN的變化規(guī)律時(shí)發(fā)現(xiàn)，0～60 cm土層的總的C、N含量沒(méi)有太大的變化，但0～30 cm根際土壤的C、N含量卻顯著增加，這主要與不同演替階段的植物群落結(jié)構(gòu)有關(guān)，土壤的性質(zhì)受植被類型、多樣性和蓋度的差異影響較大，同時(shí)SOC與TN的變化也與土壤溫度、水分、養(yǎng)分、土壤結(jié)構(gòu)和pH值的影響較大.隨著土層深度的增加，SOC與TN含量顯著減小(P<0.05)，且表層的減小幅度比土壤深層要大，主要原因在于植被的枯枝落葉開(kāi)始累積于土壤表層，深層土壤植物根系較少SOC與TN沿植物根系下滲至深層需要時(shí)間，另外，表層容易經(jīng)受環(huán)境變化的擾動(dòng)，微生物活性強(qiáng)烈，因此，表層的變化幅度較深層要大[20-21].

本實(shí)驗(yàn)發(fā)現(xiàn)演替前期SOC有時(shí)偏高，與大多數(shù)學(xué)者的研究結(jié)果不一致[22-23].筆者認(rèn)為，植被恢復(fù)對(duì)土壤影響的原因是比較復(fù)雜的，同時(shí)也與土壤對(duì)環(huán)境變化的響應(yīng)具有一定的滯后性與緩沖性有關(guān)，說(shuō)明植被恢復(fù)更有利于土壤微生物對(duì)土壤養(yǎng)分的吸收與利用[24-26].相關(guān)研究顯示，土壤微生物生物量碳(Soil microbial biomass carbon,SMBC)與土壤微生物生物量氮(Soil microbial biomass nitrogen,SMBN)對(duì)環(huán)境的變化更敏感與強(qiáng)烈，SMBC增長(zhǎng)速率的變化與微生物的自然生長(zhǎng)規(guī)律表現(xiàn)一致，當(dāng)外界營(yíng)養(yǎng)物質(zhì)大量增加時(shí)，微生物急劇增加，當(dāng)群落趨于穩(wěn)定后，其增長(zhǎng)速率則隨之降低，植被恢復(fù)過(guò)程中，土壤養(yǎng)分與微生物量關(guān)系密切[27-29].因此，需要從碳氮組分入手對(duì)植被恢復(fù)的機(jī)制進(jìn)行研究.

3.2 結(jié)論

采用時(shí)空互代法，在衡陽(yáng)紫色土丘陵坡地研究不同恢復(fù)階段與不同土層的SOC與TN的變化規(guī)律，得出以下主要結(jié)論：

1)隨著植被恢復(fù)的進(jìn)行，SOC與TN含量顯著增加(P<0.05)；

2)隨著土層深度的增加，SOC與TN含量顯著減小(P<0.05).

[1] 陳 璟,楊 寧.衡陽(yáng)紫色土丘陵坡地植被恢復(fù)對(duì)土壤活性有機(jī)碳庫(kù)的影響[J].熱帶亞熱帶植物學(xué)報(bào),2016,24(5): 568-576. Chen J,Yang N.Effects of re-vegetation on active organic carbon pool of purple soils on sloping-land in Hengyang,Hunan Province,China[J].Journal of Tropical and Subtropical Botany,2016,24(5): 568-576.

[2] 文東新,楊 寧,楊滿元.衡陽(yáng)紫色土丘陵坡地植被恢復(fù)對(duì)土壤微生物功能多樣性的影響[J].應(yīng)用生態(tài)學(xué)報(bào),2016,27(8): 2 645-2 654. Wen D X,Yang N,Yang M Y.Effects of re-vegetation on soil microbial functional diversity in purple soils at different re-vegetation stages in Hengyang,Hunan Province,China [J].Chinese Journal of Applied Ecology,2016,27(8):2 645-2 654.

[3] Ghani A,Dexter M,Perrott K W.Hot-water extractable carbon in soils: A sensitive measurement for determining impacts of fertilization,grazing and cultivation[J].Soil Biology & Biochemistry,2003,35(9): 1 231-1 243.

[4] 楊 寧,鄒冬生,楊滿元,等.衡陽(yáng)紫色土丘陵坡地植被不同恢復(fù)階段土壤微生物量碳的變化及其與土壤理化因子的關(guān)系[J].生態(tài)環(huán)境學(xué)報(bào),2013,22(1): 25-30. Yang N,Zou D S,Yang M Y,et al.The change of soil microbial biomass carbon and the relationship between it and soil physio-chemical factors in different restoration stages on sloping-land with purple soils in Hengyang[J].Ecology and Environmental Sciences,2013,22(1): 25-30.

[5] Smith C K,Munson A D,Coyea M R,et al.Nitrogen and phosphorous release from humus and mineral soil under black spruce forests in Central Quebec[J].Soil Biology & Biochemistry,1998,30(12): 1 491-1 500.

[6] 楊 寧,楊滿元,鄒冬生,等.紫色土丘陵坡地恢復(fù)過(guò)程中土壤微生物生物量碳與水溶性有機(jī)碳變化特征[J].草地學(xué)報(bào),2016,24(4):812-818. Yang Ning,Yang Man-yuan,Zou Dong-sheng,et al.Dynamics of soil microbial biomass carbon and soil water soluble organic carbon along re-vegetation chronosequences on hillslope land with purple soils[J].Acta Agrestia Sinica,2016,24(4):812-818.

[7] 向澤宇,張 莉,張全發(fā),等.青海不同林分類型土壤養(yǎng)分與微生物功能多樣性[J].林業(yè)科學(xué),2014,50(4):22-31. Xiang Ze-yu,Zhang Li,Zhang Quan-fa,et al.Soil nutrients and microbial functional diversity of different stand types in Qinghai Province[J].Scientia Silvae Sinicae,2014,50(4):22-31.

[8] 楊 寧,付美云,楊滿元,等.衡陽(yáng)紫色土丘陵坡地不同土地利用模式下土壤種子庫(kù)特征[J].西北植物學(xué)報(bào),2014,34(11): 2 324-2 330. Yang N,Fu M Y,Yang M Y,et al.Soil seed bank properties under different land-used models on sloping-land with purple soils in Hengyang of Hunan Province,South-central China[J].Acta Botanica Boreali-occidentalia Sinica,2014,34(11): 2 324-2 330.

[9] 吳則焰,林文雄,陳志芳,等.中亞熱帶森林土壤微生物群落多樣性隨海拔梯度的變化[J].植物生態(tài)學(xué)報(bào),2013,37(5):397-406. Wu Ze-yan,Lin Wen-xiong,Chen Zhi-fang,et al.Variations of soil microbial community diversity along an elevational gradient in mid-subtropical forest[J].Chinese Journal of Plant Ecology,2013,37(5):397-406.

[10] 周 桔,雷 霆.土壤微生物多樣性影響因素及研究方法的現(xiàn)狀與展望[J].生物多樣性,2007,15(3):306-311. Zhou Ju,Lei Ting.Review and prospects on methodology and affecting factors of soil microbial diversity[J].Biodiversity Science,2007,15(3):306-311.

[11] Holt J A.Grazing pressure and soil carbon,microbial biomass and enzyme activities in semi-arid northeastern Australia[J].Applied Soil Ecology,1997(5): 143-149.

[12] 楊 寧,鄒冬生,楊滿元,等.衡陽(yáng)紫色土丘陵坡地植被恢復(fù)階段土壤特性的演變[J].生態(tài)學(xué)報(bào),2014,34(10): 2 693-2 701. Yang N,Zou D S,Yang M Y,et al.Changes of the soil properties in re-vegetation stages on sloping-land with purple soils in Hengyang of Hunan Province,South-central China [J].Acta Ecologica Sinica,2014,34(10): 2 693-2 701.

[13] 范 適,楊 寧.亞熱帶5個(gè)生態(tài)系統(tǒng)土壤微生物學(xué)性質(zhì)比較[J].熱帶亞熱帶植物學(xué)報(bào),2016,24(6):635-641. Fan Shi,Yang Ning.Comparsion of soil microbiology characteristics in five subtropical ecosystems[J].Journal of Tropical and Subtropical Botany,2016,24(6):635-641.

[14] 楊 寧,鄒冬生,楊滿元,等.衡陽(yáng)紫色土丘陵坡地不同植被恢復(fù)階段土壤酶活性特征研究[J].植物營(yíng)養(yǎng)與肥料學(xué)報(bào),2013,19(6): 1 516-1 524. Yang N,Zou D S,Yang M Y,et al.Soil enzyme activities in different re-vegetation stages on sloping-land with purple soils in Hengyang of Hunan Province,China[J].Journal of Plant Nutrition and Fertilizer,2013,19(6): 1 516-1 524.

[15] 陳 璟,楊 寧.衡陽(yáng)紫色土丘陵坡地不同恢復(fù)階段土壤基礎(chǔ)呼吸及代謝熵的變化[J].熱帶亞熱帶植物學(xué)報(bào),2013,21(6): 514-520. Chen J,Yang N.Changes in SBR and qCO2at different re-vegetation stages on sloping-land with purple soils in Hengyang of Hunan Province,South-central China[J].Journal of Tropical and Subtropical Botany,2013,21(6): 514-520.

[16] 魏 媛,喻理飛,張金池.退化喀斯特植被恢復(fù)過(guò)程中土壤微生物活性研究[J].林業(yè)科學(xué),2008,44(7):6-10. Wei Yuan,Yu Li-fei,Zhang Jin-chi.Soil microbial characteristics during succession of degraded Karst vegetation[J].Sientia Silvae Sinicae,2008,44(7):6-10.

[17] 楊滿元,楊 寧.衡陽(yáng)紫色土丘陵坡地植被恢復(fù)過(guò)程中土壤生化強(qiáng)度變化[J].生態(tài)環(huán)境學(xué)報(bào),2015,24(7): 1 125-1 127. Yang M Y,Yang N.Dynamic changes of soil biochemical intensity along re-vegetation on sloping-land with purple soils in Hengyang of Hunan Province,South-central China[J].Ecology and Environmental Sciences,2015,24(7): 1 125-1 127.

[18] Gao Y H,Schumann M.Impacts of grazing intensity on soil carbon and nitrogen in an alpine meadow on the eastern Tibetan Plateau[J].Food,Agriculture & Environment,2009(7): 749-754.

[19] Schuman G E,Reeder J D,Manley J T,et al.Impact of grazing management on the carbon and nitrogen balance of a mixed-grass rangeland[J].Ecological Applications,1999,9(1): 65-71.

[20] 楊 寧,鄒冬生,楊滿元,等.衡陽(yáng)紫色土丘陵坡地不同恢復(fù)階段植被特征與土壤性質(zhì)的關(guān)系[J].應(yīng)用生態(tài)學(xué)報(bào),2013,24(1):90-96. Yang Ning,Zou Dong-sheng,Yang Man-yuan,et al.Relationships between vegetation characteristics and soil properties at different restoration stages on slope land with purple soils in Hengyang of Hunan Province,South-central China[J].Chinese Journal of Applied Ecology,2013,24(1):90-96.

[21] 楊 寧,鄒冬生,楊滿元,等.衡陽(yáng)紫色土丘陵坡地恢復(fù)過(guò)程中土壤微生物生物量與土壤養(yǎng)分演變[J].林業(yè)科學(xué),2014,50(12): 144-150. Yang N,Zou D S,Yang M Y,et al.Dynamic changes of soil microbial biomass and soil nutrients along re-vegetation on sloping-land with purple soils in Hengyang of Hunan Province,South-central China[J].Scientia Silvae Sinicae,2014,50(12): 144-150.

[22] Bauer A,Cole C V,Black A L.Soil property comparisons in virgin grasslands between grazed and nongrazed management systems[J].Soil Science Society of America Journal,1987,51: 176-182.

[23] Desjardins T,Andreux F,Volkoff B,et al.Organic carbon and 13C contents in soils and soil size fractions,and their changes due to deforestation and pasture installation in eastern Amazonia[J].Geoderma,1994,61: 103-113.

[24] 楊 寧,鄒冬生,李建國(guó).衡陽(yáng)盆地紫色土丘陵坡地植被恢復(fù)模式建設(shè)[J].草業(yè)科學(xué),2010,27(10): 10-16. Yang N,Zou D S,Li J G.The vegetation restoration mode construction in sloping-land with purple soils in Hengyang basin[J].Pratacultural Science,2010,27(10): 10-16.

[25]Holt J A,Bristow K L,Mclvor J G.The effects of grazing pressure in soil animals and hydraulic properties of two soils in semi-arid tropical Queensland[J].Australia Journal of Soil Research,1996,34: 69-79.

[26]楊 寧,鄒冬生,付美云,等.紫色土丘陵坡地恢復(fù)中土壤團(tuán)聚體特征及其與土壤性質(zhì)的關(guān)系[J].生態(tài)學(xué)雜志,2016,35(9): 2 361-2 368. Yang N,Zou D S,Fu M Y,et al.Properties of soil aggregates in purple soils during re-vegetation on sloping land in relation to soil characteristics[J].Chinese Journal of Ecology,2016,35(9): 2 361-2 368.[27]劉朝輝,楊 寧.湖南省衡陽(yáng)市紫色土丘陵坡地不同恢復(fù)階段植物群落穩(wěn)定性 [J].湖南生態(tài)科學(xué)學(xué)報(bào),2016,3(1): 7-12. Liu C H,Yang N.Stability of plant communities in different re-vegetation stages on sloping-land with purple soils in Hengyang City,Hunan Province[J].Journal of Hunan Ecological Science,2016,3(1): 7-12.

[28]陳 璟,楊 寧.衡陽(yáng)紫色土丘陵坡地不同植被恢復(fù)過(guò)程中土壤水文效應(yīng)[J].中國(guó)生態(tài)農(nóng)業(yè)學(xué)報(bào),2013,21(5): 590-597. Chen J,Yang N.Soil hydrological function at different vegetation restoration stages in purple soil slopelands in Hengyang[J].Chinese Journal of Eco-Agriculture,2013,21(5): 590-597.

[29]楊 寧,鄒冬生,楊滿元,等.衡陽(yáng)紫色土丘陵坡地不同植被恢復(fù)階段土壤微生物群落多樣性的變化[J].林業(yè)科學(xué),2016,52(8): 146-156. Yang N,Zou D S,Yang M Y,et al.Variations of soil microbial community diversity in purple soils at different re-vegetation stages on sloping-land in Hengyang,Hunan Province,South-central China[J].Scientia Silvae Sinicae,2016,52(8): 146-156.

Biography：GUI De-zhi,male,born in 1977,assistant engineer,research direction: forest cultivation and forest ecology.

Effects of Re-vegetation on Soil Organic Carbon and Total Nitrogen in PurpleSoils on Sloping-land in Hengyang of Hunan

GUI De-zhi1, KUANG Yi-ming1, ZHANG Wei-guo1, WEN Dong-xin2

(1.Qiyang County Guabang Mountain Forest Farm,Qiyang426100,China; 2.College of Science,Central South University of Forestry and Technology,Changsha 410004,China)

The re-vegetation stages were classified into successive early stage,middle stage and later stage by using an approach of spatial sequence instead of temporal sequence,and the soil organic carbon(SOC) and total nitrogen(TN) in 0～10,10～20,20～30 and 30～40 cm soil layer of three successive stages were respectively measured.The results showed that: 1)In the process of re-vegetation,the contents of SOC and TN in each soil layer significantly increased(P<0.05),which order followed as later stage(SOC,TN)>middle stage(SOC,TN)>early stage(SOC,TN); 2)With increase of soil depth,SOC and TN significantly decreased(P<0.05),which order followed as 0～10 cm soil layer(SOC,TN)>10～20 cm soil layer(SOC,TN)>20～30 cm soil layer(SOC,TN)>30～40 cm soil layer(SOC,TN).1fig.,3tabs.,29refs.

soil organic carbon(SOC); total nitrogen(TN); re-vegetation; Hengyang.

2016-09-15

國(guó)家“十五”農(nóng)業(yè)科技重大專項(xiàng)資助(編號(hào): 2001BA507A)

桂德志(1977-)，男，湖南祁陽(yáng)人，助理工程師，研究方向：森林培育與森林生態(tài).

2095-7300(2016)04-018-05

S153.6

A