李學(xué)斌, 陳林,樊瑞霞,吳秀玲,謝應(yīng)忠
(1.寧夏大學(xué)西北土地退化與生態(tài)恢復(fù)國(guó)家重點(diǎn)實(shí)驗(yàn)室培育基地,銀川750021;2.寧夏農(nóng)業(yè)勘查設(shè)計(jì)院,銀川750001)
圍封條件下荒漠草原4種典型植物群落枯落物輸入對(duì)土壤理化性質(zhì)的影響
李學(xué)斌1*, 陳林1,樊瑞霞1,吳秀玲2,謝應(yīng)忠1
(1.寧夏大學(xué)西北土地退化與生態(tài)恢復(fù)國(guó)家重點(diǎn)實(shí)驗(yàn)室培育基地,銀川750021;2.寧夏農(nóng)業(yè)勘查設(shè)計(jì)院,銀川750001)
采用野外原位實(shí)驗(yàn)和室內(nèi)控制實(shí)驗(yàn)相結(jié)合的方法研究了圍封條件下荒漠草原4種典型植物群落(沙蘆草群落、甘草群落、賴草群落和沙蒿群落)枯落物分解對(duì)土壤理化性質(zhì)的影響.結(jié)果表明:荒漠草原4種典型植被群落圍封內(nèi)枯落物蓄積量顯著高于圍封外,枯落物的蓄積增加了土壤的持水量,但枯落物的分解短期內(nèi)對(duì)土壤體積質(zhì)量、孔隙度及持水性能影響較?。豢萋湮镌诜纸膺^(guò)程中,由于積累了大量腐殖酸導(dǎo)致了p H值降低,且土壤的p H值也呈降低趨勢(shì),但變化幅度不大,與枯落物p H值呈現(xiàn)一定的擬合效果;枯落物輸入短期內(nèi)對(duì)土壤全氮和有機(jī)碳有正效應(yīng).荒漠草原枯落物蓄積與分解能有效改善土壤中的水分運(yùn)移與空間分布,并為土壤注入更多的有機(jī)質(zhì)和養(yǎng)分元素,從而改變土壤理化性質(zhì).“退耕還草”“封欄封育”等國(guó)家重大生態(tài)工程地實(shí)施對(duì)荒漠草原植被與土壤的恢復(fù)產(chǎn)生了積極的影響.
荒漠草原;枯落物;土壤理化性質(zhì)
SummaryLitter not only can avoid plants being suffered from splash erosion,wind erosion and other physical protection of rain,but also can accelerate the accumulation of soil moisture,nutrients,and improve soil fertility.In the last decade,The National Projects of Ecological Engineering such as Returning Cropland to Grass and Enclosure Steppe,have been performed,but effects of litter input on soil physical and chemical properties under the fenced condition in desert steppe remain poorly understood.
We created field decomposition experiment and laboratory experiment based on four typical plant communities under a fenced condition,which were Agropyron crisatum community,Glycyrrhiza uralensis community,Leymus secalinus community and Artemisia desertorum community,and analyzed the basic characteristics of four typical plant communities,litter accumulation and decomposition,and soil moisture and nutrients,respectively.
The results showed that the litter accumulation under the fenced condition was significantly higher than that of the no fenced condition,and the litter accumulation increased soil water holding capacity,while the litter decomposition had weak effect on soil bulk density,total porosity and water holding capacity in the short term. Although soil p H value decreased with the litter accumulation,but the variation was small.Litter input had positive effect on the soil total nitrogen in the short-term,but the effect was weak,and the soil total nitrogen and organic carbon increased with increasing litter accumulation.These results supported that the litter accumulation and decomposition in the desert steppe could effectively improve the soil water movement and spatial distribution,and transport more organic and nutrient elements into the soil,thus change the physical and chemical properties of soil.
The finding suggests that litter has positive effect on vegetation and soil restoration of the desert steppe,which plays more important role in maintaining ecosystem stability in the arid sand areas.
枯落物作為養(yǎng)分的基本載體,在養(yǎng)分循環(huán)中成為連接植物與土壤的重要“紐帶”,是草地生態(tài)系統(tǒng)養(yǎng)分循環(huán)的物質(zhì)基礎(chǔ),在養(yǎng)分循環(huán)和維持土壤肥力等方面發(fā)揮著非常重要的作用[1-2].目前,有關(guān)枯落物的研究已經(jīng)從枯落物的枯落量、分解過(guò)程及影響因子等基本特征,深入到枯落物對(duì)土壤性質(zhì)、植物生長(zhǎng)、群落的演替,以及植被生產(chǎn)力等生態(tài)功能的研究上[3-4].關(guān)于枯落物與土壤性質(zhì)的關(guān)系,國(guó)內(nèi)外也有大量的研究報(bào)道[5-6],陳光升等[7]對(duì)西南山地森林凋落物回歸土壤后的研究表明,凋落物分解輸入對(duì)土壤體積質(zhì)量、孔隙度等影響不大,但土壤p H值升高,且有機(jī)碳及氮含量呈升高的趨勢(shì);馬存平等[8]研究結(jié)果表明,枯落物的輸入能夠降低土壤體積質(zhì)量,減少土壤的無(wú)效蒸發(fā),增加土壤的蓄水能力,同時(shí),土壤有機(jī)質(zhì)、全量養(yǎng)分含量均有顯著增加.但這些研究主要集中在森林生態(tài)系統(tǒng)及西南山地和東北等典型草原生態(tài)系統(tǒng),而對(duì)荒漠草原鮮有研究.
近年來(lái),隨著“西部大開(kāi)發(fā)”“退耕還林還草”“封育禁牧”等重大生態(tài)工程的實(shí)施,草地生態(tài)系統(tǒng)得到了不同程度的休養(yǎng)生息,在家畜等草食性動(dòng)物退出草地生態(tài)系統(tǒng)后,枯落物成為聯(lián)系植被與土壤的重要中間環(huán)節(jié),但是植被枯落物分解如何影響土壤性質(zhì),如何更好地發(fā)揮草地生態(tài)系統(tǒng)的自我維持機(jī)制等問(wèn)題尚未解決.故本試驗(yàn)基于北方農(nóng)牧交錯(cuò)帶“退耕還草”和“封育禁牧”后荒漠草原恢復(fù)的實(shí)際情況,選擇荒漠草原4種典型植物群落枯落物分解對(duì)土壤理化性質(zhì)的影響加以研究,揭示枯落物分解與輸入對(duì)土壤的生態(tài)效應(yīng),為植被恢復(fù)和草地的合理利用提供理論基礎(chǔ).由于草地土壤直接接納枯落物的物質(zhì)輸送和分解轉(zhuǎn)化主要對(duì)土壤表層有影響,因此本文以表層土壤(0~15 cm)來(lái)討論枯落物分解對(duì)土壤理化性質(zhì)的影響.
1.1 研究地點(diǎn)
實(shí)驗(yàn)樣地位于寧夏鹽池縣國(guó)家級(jí)草原資源管理監(jiān)測(cè)站(37.95°N,107.00°E),該研究區(qū)屬于典型中溫帶大陸性氣候,年平均氣溫為8.1℃,近50年年平均降雨量為288 mm,且主要集中在5—9月,約占年降雨量的60%;年平均無(wú)霜期為165 d;土壤類型主要為灰鈣土和風(fēng)沙土.植物類型主要以灌叢沙生植被和荒漠植被為主,植物群落中常見(jiàn)種類以旱生和中旱生為主.樣地封育時(shí)間為2001年.研究對(duì)象選取了荒漠草原4種典型植物群落:沙蘆草群落、甘草群落、賴草群落和沙蒿群落.基本情況見(jiàn)表1.
1.2 研究方法
采用野外原位實(shí)驗(yàn)和室內(nèi)控制實(shí)驗(yàn)相結(jié)合的方法研究荒漠草原4種植物群落枯落物分解對(duì)土壤理化性質(zhì)的影響.
野外原位實(shí)驗(yàn):采用“枯落物袋擲入法”.2012年4月5日,將4種植物群落的枯枝落葉進(jìn)行收集,帶回實(shí)驗(yàn)室65℃烘干后稱質(zhì)量20 g,剪成5 cm左右的小段,裝入大小為25 cm×25 cm的尼龍網(wǎng)袋中,按“S”型隨機(jī)置于樣地作為處理,埋入10 cm左右的土層中,清除地表的枯落物層,于5、6、8、9、10月在枯落物分解袋周圍采集土樣,帶回實(shí)驗(yàn)室進(jìn)行土壤體積質(zhì)量、孔隙度、土壤水分等物理性質(zhì)和p H值、有機(jī)碳、全氮、速效磷、速效鉀等化學(xué)性質(zhì)分析;同時(shí),采集鄰近的未放置枯落物分解袋的土壤(每月清理地表的枯落物,使其不受枯落物的影響)作為對(duì)照.設(shè)置3個(gè)重復(fù).
室內(nèi)控制實(shí)驗(yàn):在埋置枯落物袋的同時(shí),分別在每個(gè)樣地內(nèi)采集0~15 cm土層的土壤,帶回實(shí)驗(yàn)室過(guò)2 mm篩,在25℃人工氣候培養(yǎng)箱中培養(yǎng)7 d,然后稱取300 g鮮土,加入質(zhì)量為4.0 g的枯落物,混合均勻,將制備好的土壤裝入250 m L燒杯中,燒杯口用塑料薄膜密封,在薄膜上用針刺若干個(gè)通氣小孔,每個(gè)時(shí)期各處理設(shè)置3次重復(fù).沒(méi)有放置枯落物的為對(duì)照.將燒杯置入人工氣候箱中,在溫度為(25±0.5)℃、相對(duì)濕度為(70±5)%、光照為晝夜交替的條件下分別培養(yǎng)0、15、30、60、90 d后測(cè)定土壤理化性質(zhì).
表1 荒漠草原4種典型植物群落樣地基本特征Table 1 Basic characteristics of four typical plant communities in the desert steppe
2.1 枯落物對(duì)土壤物理性質(zhì)的影響
2.1.1 枯落物對(duì)土壤體積質(zhì)量、孔隙狀況的影響
土壤體積質(zhì)量是表征土壤質(zhì)量的重要參數(shù)之一,是土壤緊實(shí)度的敏感性指標(biāo)[9].結(jié)果(表2)表明:荒漠草原4種植物群落有枯落物袋處理的土壤體積質(zhì)量在實(shí)驗(yàn)期內(nèi)與對(duì)照相比變化極小,沒(méi)有明顯的規(guī)律性改變,說(shuō)明荒漠草原枯落物分解在較短時(shí)間內(nèi)對(duì)土壤體積質(zhì)量的影響很小,幾乎不變.土壤孔隙度也稱土壤孔度,充滿著水分與空氣,其大小、數(shù)量與分配是土壤物理性質(zhì)的重要基礎(chǔ),也是評(píng)價(jià)土壤結(jié)構(gòu)特征的重要指標(biāo)[10-11].4種植物群落有枯落物袋的處理和無(wú)枯落物的對(duì)照相比,土壤總孔隙度、毛管孔隙度、非毛管孔隙度均沒(méi)有顯著差異,說(shuō)明在短期內(nèi)枯落物分解對(duì)土壤的孔隙狀況影響也是有限的.
2.1.2 枯落物對(duì)土壤持水性能的影響 土壤的持水性能是影響土壤抗雨水擊濺和水蝕能力的體現(xiàn),是反映土壤生態(tài)學(xué)功能的一項(xiàng)重要指標(biāo)[12].結(jié)果(表3)表明:沙蘆草群落和甘草群落土壤最大持水量、毛管持水量、最小持水量處理均高于對(duì)照,增幅分別在4.29%~8.88%、4.75%~13.77%、5.56%~16.36%和2.34%~2.61%、2.57%~2.88%、2.96%~3.34%之間;賴草群落和沙蒿群落土壤持水性能在實(shí)驗(yàn)期內(nèi)沒(méi)有表現(xiàn)出較強(qiáng)的規(guī)律性.田超等[13]研究表明,枯落物的輸入能夠改變土地物理性質(zhì),提高土壤的持水性能.該研究說(shuō)明荒漠草原枯落物蓄積與分解對(duì)土壤的持水量產(chǎn)生了一定影響,但影響結(jié)果有待于長(zhǎng)時(shí)段的研究數(shù)據(jù)來(lái)支撐.
2.2 枯落物對(duì)土壤化學(xué)性質(zhì)的影響
2.2.1 枯落物對(duì)土壤p H值的影響 土壤酸堿度是描述土壤性質(zhì)的重要指標(biāo)之一,枯落物可改變土壤的p H值,從而影響了營(yíng)養(yǎng)元素的可利用性;枯落物通過(guò)誘導(dǎo)土壤p H值的變化進(jìn)而影響土壤的物理結(jié)構(gòu),因此也影響水分的滲透[14].研究結(jié)果(表4)顯示,荒漠草原4種植物群落枯落物在不同分解時(shí)期p H值變化范圍在6.40~7.38之間,整體呈中、偏堿性,且隨著分解進(jìn)程有降低的趨勢(shì),分解初期(5月份)p H值最高,分解末期(10月份)p H值最低.推測(cè)認(rèn)為,土壤中積累了大量枯落物分解合成的腐殖酸導(dǎo)致了p H的降低.而4種植物群落土壤p H值范圍在8.61~9.11之間,土壤整體偏堿性(表5).總的來(lái)看,土壤p H值大小表現(xiàn)為沙蒿群落>
賴草群落>沙蘆草群落>甘草群落;隨著分解時(shí)間的延長(zhǎng),4種群落土壤p H值均表現(xiàn)為先升高后降低的趨勢(shì),且生長(zhǎng)季末凈值較生長(zhǎng)季初低,降幅為0.45%~0.56%;處理和對(duì)照相比,4種群落的土壤p H值總體表現(xiàn)為對(duì)照>處理,差異顯著性隨群落不同而有所不同,分解期內(nèi),賴草群落對(duì)照和處理之間均無(wú)顯著差異,沙蘆草和沙蒿群落僅在6月份處理和對(duì)照之間有顯著差異,甘草群落則在4和8月期間有顯著差異.當(dāng)然,枯落物對(duì)土壤p H值的影響還需要長(zhǎng)時(shí)段、連續(xù)的實(shí)驗(yàn)監(jiān)測(cè).
表2 枯落物對(duì)0~12cm土層土壤體積質(zhì)量和孔隙狀況的影響Table2 Effect of litter on soi lvolume mass and porosity condition of 0-15 cm soil layer
表3 枯落物蓄積與分解對(duì)0~12cm土層土壤持水性能的影響Table3 Effectoflitteraccumulationanddecompositiononsoilwaterholdingcapacityof0 15cmsoillayer
表4 枯落物不同分解時(shí)期的p H值Table 4 p H value of litter decomposition in different time
表5 枯落物分解對(duì)土壤0~12 cm土層p H值的影響Table 5 Effect of litter decomposition on p H value of 0-15 cm soil layer
2.2.2 枯落物對(duì)土壤全氮含量變化的影響 荒漠草原4種植物群落類型土壤全氮含量的室內(nèi)控制實(shí)驗(yàn)結(jié)果(圖1)表明,在培養(yǎng)期內(nèi),4種群落土壤全氮含量總體變化趨勢(shì)為先降低后升高,在0~15 d內(nèi),呈降低的趨勢(shì),30~90 d逐漸升高,90 d達(dá)到最大值;處理土壤全氮含量與對(duì)照相比,總體為處理高于對(duì)照,但差別極小,增幅在1.85%~17.24%,且0~30 d的增幅(1.85%~13.04%)小于60~90 d的增幅(7.32%~17.24%).陳玉平等[15]研究表明,枯落物輸入能夠顯著增加土壤氮和有機(jī)質(zhì)的含量.該研究分析認(rèn)為,對(duì)于荒漠草原而言,枯落物對(duì)土壤全氮含量的影響需要較長(zhǎng)的時(shí)間才能顯現(xiàn).
圖1 在室內(nèi)培養(yǎng)條件下添加枯落物土壤全氮質(zhì)量分?jǐn)?shù)的變化Fig.1 Effect of litter addition on total nitrogen content of soil under the condition of laboratory incubation
圖2 在野外實(shí)驗(yàn)中添加枯落物土壤全氮質(zhì)量分?jǐn)?shù)的變化Fig.2 Effect of litter addition on total nitrogen content of soil under the condition of field experiment
野外原位實(shí)驗(yàn)結(jié)果(圖2)表明:甘草群落土壤全氮含量的季節(jié)動(dòng)態(tài)為降低趨勢(shì),氮含量最大月(4月份)與最低月(10月份)相差0.06 g/kg.4種群落土壤全氮含量均較低,室內(nèi)測(cè)定數(shù)據(jù)介于0.21~0.53 g/kg之間,低于1.00 g/kg;野外測(cè)定數(shù)據(jù)全部介于0.23~0.39 g/kg之間,更是低于0.50 g/ kg.4種群落基本表現(xiàn)為春季與秋季土壤全氮含量略高,夏季較低,這可能與該地區(qū)春、秋2季土壤水分含量較高,促進(jìn)了養(yǎng)分的循環(huán)與流動(dòng);同一時(shí)期不同群落類型相比,甘草群落土壤全氮含量最高,沙蒿群落最低,沙蘆草與賴草群落之間差異不大.無(wú)論是野外實(shí)驗(yàn)還是室內(nèi)實(shí)驗(yàn),均表現(xiàn)出處理高于對(duì)照,但差異較小,因此對(duì)荒漠草原而言,枯落物輸入短期內(nèi)對(duì)土壤全氮含量影響是有限的.
但是,室內(nèi)實(shí)驗(yàn)與野外實(shí)驗(yàn)也有差異.室內(nèi)培養(yǎng)15 d時(shí),土壤全氮含量下降為0.27 g/kg,之后呈緩慢上升的趨勢(shì),90 d時(shí),土壤全氮含量為0.41 g/ kg,比對(duì)照上升了0.11 g/kg,增加了26.8%.造成野外實(shí)驗(yàn)與室內(nèi)實(shí)驗(yàn)差異的原因可能在于:一方面,野外枯落物分解受環(huán)境因素影響,分解緩慢,養(yǎng)分釋放較少;另一方面,生長(zhǎng)季內(nèi)植物從土壤中吸收氮素,致使野外實(shí)驗(yàn)土壤全氮含量低于室內(nèi)實(shí)驗(yàn);另外,野外實(shí)驗(yàn)中土壤氮素受淋溶等作用,總體呈降低的趨勢(shì).處理與對(duì)照相比,除8月份處理低于對(duì)照外,其他月份均為處理高于對(duì)照,說(shuō)明甘草群落枯落物的分解導(dǎo)致了土壤全氮含量的升高,但處理與對(duì)照的變化很小,最大也僅相差10%.
2.2.3 枯落物對(duì)土壤有機(jī)碳的影響 4種植物群落枯落物輸入后土壤有機(jī)碳含量隨時(shí)間變化的室內(nèi)實(shí)驗(yàn)結(jié)果見(jiàn)圖3.在不同時(shí)期,不同植物群落土壤有機(jī)碳的變化范圍為4.31~16.48 g/kg,變幅較大,最大值是最小值的3.8倍,賴草和沙蒿群落土壤有機(jī)碳含量隨著培養(yǎng)時(shí)間的增加呈遞增的趨勢(shì),而沙蘆草和甘草群落隨時(shí)間的變化規(guī)律性不明顯.甘草群落土壤有機(jī)碳含量最大,其次為沙蘆草、賴草,沙蒿最小.在實(shí)驗(yàn)期內(nèi),4種植物群落土壤有機(jī)碳含量處理均高于對(duì)照,沙蒿群落增幅最大,最大增幅接近1倍,其他3種群落增幅在15.05%~51.95%之間.
4種植物群落野外實(shí)驗(yàn)土壤有機(jī)碳含量隨時(shí)間變化的結(jié)果見(jiàn)圖4.沙蒿群落土壤有機(jī)碳含量隨著分解時(shí)間的延長(zhǎng)整體呈現(xiàn)出升高的趨勢(shì),甘草、沙蘆草和賴草群落均是5、6和9月的含量較低,4和8月維持在一年中的中等水平,10月則達(dá)到了最大值,這可能是由于在雨水相對(duì)豐富的生長(zhǎng)季,植物生長(zhǎng)旺盛,引起了土壤有機(jī)碳含量短期內(nèi)的下降;沙蘆草群落土壤有機(jī)碳含量在5、6和8月處理低于對(duì)照,其他月份處理高于對(duì)照,甘草群落5、6月處理低于對(duì)照,8、9、10月處理高于對(duì)照,賴草群落僅在5月處理低于對(duì)照,而沙蒿群落在整個(gè)生長(zhǎng)季內(nèi)均表現(xiàn)為處理高于對(duì)照;甘草群落土壤有機(jī)碳含量最大,其次為沙蘆草、賴草,沙蒿最小,與室內(nèi)結(jié)果一致.
圖3 在室內(nèi)培養(yǎng)條件下添加枯落物土壤有機(jī)碳質(zhì)量分?jǐn)?shù)的變化Fig.3 Effect of litter addition on soil organic carbon content under the condition of laboratory
圖4 在野外實(shí)驗(yàn)中添加枯落物土壤有機(jī)碳質(zhì)量分?jǐn)?shù)的變化Fig.4 Effect of litter addition on soil organic carbon content under the condition of field experiment
水分和有機(jī)質(zhì)的積累是荒漠草原植物恢復(fù)、土壤正向演替的兩大動(dòng)力源[16].荒漠草原枯落物蓄積與分解能有效改善土壤中水分運(yùn)移與空間分布,并為土壤注入更多的有機(jī)質(zhì)和養(yǎng)分元素,從而改變土壤理化性質(zhì).枯落物的存在不僅可以避免土壤受到雨滴的擊濺侵蝕、風(fēng)蝕而起到物理保護(hù)的作用,還可以加速土壤水分、養(yǎng)分的蓄積,提高土壤肥力,加速土壤的正向演替[17].
Herandez等[18]認(rèn)為,土壤體積質(zhì)量大小和孔隙狀況主要受到土壤顆粒組成、土壤有機(jī)質(zhì)含量、放牧踐踏等因素的影響.在本研究中,枯落物輸入后土壤體積質(zhì)量比無(wú)枯落物輸入土壤體積質(zhì)量略高,但差異不顯著.土壤總孔隙度、毛管孔隙度、非毛管孔隙度在有或無(wú)枯落物輸入情況下沒(méi)有明顯的規(guī)律性.這可能是由于本項(xiàng)研究實(shí)驗(yàn)周期較短.馬艷萍等[19]認(rèn)為,在荒漠草原典型的表層沙化動(dòng)力系統(tǒng)中,植被生產(chǎn)力低,地表裸露率高,風(fēng)成過(guò)程極易產(chǎn)生.而“封育禁牧”使得荒漠草原枯落物的蓄積直接覆蓋在表層土壤上,增加了表層土壤的粗糙系數(shù)和持水性能.本實(shí)驗(yàn)的4個(gè)群落圍封內(nèi)枯落物蓄積量顯著高于圍封外.
荒漠草原枯落物的蓄積與分解可以促進(jìn)土壤酸堿度的改變.徐秋芳等[20]研究發(fā)現(xiàn),不同樹(shù)木枯落物的分解對(duì)土壤p H值產(chǎn)生一定的影響,如杉木、馬尾松的枯落物分解使得土壤p H值降低,而檫木枯落物分解使得土壤p H值升高.也有學(xué)者認(rèn)為枯落物不會(huì)影響土壤的酸堿性[21].本研究4種植物群落枯落物在分解過(guò)程中p H值總體呈現(xiàn)降低的趨勢(shì),這是由于枯落物經(jīng)分解和腐殖化,轉(zhuǎn)變成為腐殖質(zhì),腐殖質(zhì)中含有腐殖質(zhì)酸.而在枯落物輸入后,土壤p H值隨分解時(shí)間的延長(zhǎng)呈現(xiàn)上下波動(dòng),總體略降低,但變化幅度不大,與枯落物p H值呈現(xiàn)一定的擬合效果.這是因?yàn)閷幭柠}池縣荒漠草原地下水相對(duì)較低,土壤鹽堿化程度嚴(yán)重,枯落物的分解和腐殖化過(guò)程提高了土壤中CO2和有機(jī)酸的含量和濃度,在一定程度上中和堿性土壤,改善土壤理化性質(zhì).說(shuō)明荒漠草原封育禁牧后,枯落物的輸入對(duì)改善土壤酸堿度有一定作用,但本實(shí)驗(yàn)還缺乏長(zhǎng)時(shí)段、序列性研究數(shù)據(jù)支撐.
在同一地區(qū),深層土壤的理化性質(zhì)相對(duì)比較穩(wěn)定,而表層土壤受枯落物和植被影響較大[22].枯落物的蓄積量、分解和組分等因素不同程度影響著表層土壤的C、N、P、K等養(yǎng)分的含量.在本實(shí)驗(yàn)中,無(wú)論是室內(nèi)實(shí)驗(yàn)還是野外實(shí)驗(yàn),枯落物的輸入對(duì)土壤全氮含量均呈正態(tài)效應(yīng),但土壤全氮含量的變化總體都比較小,這是因?yàn)橥寥廊康?5%以上都是有機(jī)形態(tài)的,不易受到外界環(huán)境的影響,因此波動(dòng)較小,這與汪思龍等[23]的研究結(jié)果類似.
以上所述,荒漠草原封育禁牧后枯落物蓄積與分解對(duì)土壤理化性質(zhì)有一定的影響,荒漠草原區(qū)植被枯落物的輸入對(duì)提高土壤肥力具有極為重要的生態(tài)學(xué)功能.
(References):
[1] 廖利平,高洪,汪思龍,等.外加氮源對(duì)杉木葉凋落物分解及土壤養(yǎng)分淋失的影響.植物生態(tài)學(xué)報(bào),2009,24(1):34-39. Liao L P,Gao H,Wang S L,et al.The effect of nitrogen addition on soil nutrient leaching and the decomposition of Chinese fir leaf litter.Chinese Journal of Plant Ecology,2009,24(1):34-39.(in Chinese with English abstract)
[2] 林波,劉慶,吳彥,等.川西亞高山針葉林凋落物對(duì)土壤理化性質(zhì)的影響.應(yīng)用與環(huán)境生物學(xué)報(bào),2003,9(4):346-351. Lin B,Liu Q,Wu Y,et al.Effect of forest litters on soil physical and chemical properties in Subalpine coniferous forests of Western Sichuan.Chinese Journal of Applied& Environmental Biology,2003,9(4):346-351.(in Chinese with English abstract)
[3] Fang C,Moncrieff J.The dependence of soil CO2efflux on temperature.Soil Biology and Biochemistry,2007,33(2):155-165.
[4] 王清奎,汪思龍,于小軍,等.杉木與闊葉樹(shù)葉凋落物混合分解對(duì)土壤活性有機(jī)質(zhì)的影響.應(yīng)用生態(tài)學(xué)報(bào),2007,23(6):1203-1207. Wang Q K,Wang S L,Yu X J,et al.Effects of Cunninghamia lanceolata-broad leaved tree species mixed leaf litters on active soil organic matter.Chinese Journal of Applied Ecology,2007,23(6):1203-1207.(in Chinese with English abstract)
[5] Brookes P,Landman A,Pruden G,et al.Chloroform fumigation and the release of soil nitrogen:A rapid direct extraction method to measure microbial biomass nitrogen in soil.Soil Biology and Biochemistry,2006,17(6):837-842.
[6] Huang W,Schoenau J.Fluxes of water-soluble nitrogen and phosphorus in the forest floor and surface mineral soil of a boreal aspen stand.Geoderma,2009,81(3):251-264.
[7] 陳光升,胡庭興,黃立華,等.華西雨屏區(qū)人工竹林凋落物及表層土壤的水源涵養(yǎng)功能研究.水土保持學(xué)報(bào),2008,22(1):159-162. Chen G S,Hu T X,Huang L H,et al.Study on water conservation function of litter and surface soil of different bamboo plantations in rainy area of west China.Journal of Soil and Water Conservation,2008,22(1):159-162.(in Chinese with English abstract)
[8] 馬存平,王海鷹,李軍保,等.封育對(duì)昭蘇馬場(chǎng)春秋草場(chǎng)土壤理化性質(zhì)的影響.安徽農(nóng)學(xué)通報(bào),2009,15(14):77-80. Ma C P,Wang H Y,Li J B,et al.Effects of fencing on soil physical and chemical properties of spring-autumn grassland in Zhaosu horse ranch.Anhui Agriculture Science Bulletin,2009,15(14):77-80.(in Chinese with English abstract)
[9] 逯軍峰,王輝,曹靖,等.油松人工林凋落物對(duì)土壤理化性質(zhì)的影響.西北林學(xué)院學(xué)報(bào),2007,22(3):25-28. Lu J F,Wang H,Gao J,et al.Effect of forest litters on soil physical and chemical properties in Pinus tabulaeformis plantation.Journal of Northwest Forestry University,2007,22(3):25-28.(in Chinese with English abstract)
[10] 張希彪,上官周平.人為干擾對(duì)黃土高原子午嶺油松人工林土壤物理性質(zhì)的影響.生態(tài)學(xué)報(bào),2010,26(11):3685-3695. Zhang X B,Shangguan Z P.Effect of human-induced disturbance on physical properties of soil in artificial Pinus tabulaeformis Carr.forests of the Loess Plateau.Acta Ecologica Sinica,2010,26(11):3685-3695.(in Chinese with English abstract)
[11] 劉增文,段而軍,高文俊,等.秦嶺山區(qū)人工林地枯落葉客置對(duì)土壤生物、化學(xué)性質(zhì)的影響.應(yīng)用生態(tài)學(xué)報(bào),2008,19(4):704-710. Liu Z W,Duan E J,Gao W J,et al.Effects of leaf litter replacement on soil biological and chemical characteristics in main artificial forests in Qinling Mountains.Chinese Journal of Applied Ecology,2008,19(4):704-710.(in Chinese with English abstract)
[12] 陳立新,陳祥偉,段文標(biāo).落葉松人工林凋落物與土壤肥力變化的研究.應(yīng)用生態(tài)學(xué)報(bào),1998,9(6):581-586. Chen L X,Chen X W,Duan W B.Larch litter and soil fertility.Chinese Journal of Applied Ecology,1998,9(6):581-586.(in Chinese with English abstract)
[13] 田超,楊新兵,李軍,等.冀北山地陰坡枯落物層和土壤層水文效應(yīng)研究.水土保持學(xué)報(bào),2011,25(2):97-103. Tian C,Yang X B,Li J,et al.Hydrological effects of forest litters and soil in the slope of North Mountain of Hebei Province.Journal of Soil and Water Conservation,2011,25(2):97-103.(in Chinese with English abstract)
[14] 郭繼勛,祝廷成.羊草草原枯枝落葉分解的研究:枯枝落葉分解與生態(tài)環(huán)境的關(guān)系.生態(tài)學(xué)報(bào),1993,13(3):214-220. Guo J X,Zhu T C.Study on litter decomposition in Leymus chinensis grassland:Relation of litter decomposition to ecological environment.Acta Ecologica Sinica,1993,13(3):214-220.(in Chinese with English abstract)
[15] 陳玉平,吳佳斌,張曼,等.枯落物處理對(duì)森林土壤碳氮轉(zhuǎn)化過(guò)程影響研究綜述.亞熱帶資源與環(huán)境學(xué)報(bào),2012,7(2):84-92. Chen Y P,Wu J B,Zhang M,et al.Research advances of effects of detritus input and removal on dynamics of carbon and nitrogen in forest soils.Journal of Subtropical Resources and Environment,2012,7(2):84-92.(in Chinese with English abstract)
[16] 周道瑋,周以良.羊草草甸草原火燒地凋落物的分解與積累速率變化.草業(yè)學(xué)報(bào),2003,2(4):51-54. Zhou D W,Zhou Y L.Effects on decomposition and accumulation of litter in Aneurolepidium Chinense steppe. Acta Prataculturae Sinica,2003,2(4):51-54.(in Chinese with English abstract)
[17] 馬琳,李學(xué)斌,謝應(yīng)忠.寧夏鹽池草地典型群落枯落物與土壤和水熱的關(guān)系.草業(yè)科學(xué),2011,28(6):898-901. Ma L,Li X B,Xie Y Z.The relationship between litter and soil and hydro-thermal conditions of typical communities of grassland in Yanchi,Ningxia.Pratacultural Science,2011,28(6):898-901.(in Chinese with English abstract)
[18] Herandez J M,Simpson S S,Hyslop M S.Device for Interconnecting Integrated Circuit Packages to Circuit Boards.U.S.Patent 5,309,324.1994-05-03.
[19] 馬艷萍,黃寧.植被與風(fēng)蝕耦合動(dòng)力學(xué)模型及其應(yīng)用.中國(guó)沙漠,2011,31(3):665-671. Ma Y P,Huang N.Coupling dynamic model of vegetation and aeolian erosion and its application.Journal of Desert Research,2011,31(3):665-671.(in Chinese with English abstract)
[20] 徐秋芳,錢(qián)新標(biāo),桂祖云.不同林木凋落物分解對(duì)土壤性質(zhì)的影響.浙江林學(xué)院學(xué)報(bào),2008,15(1):27-31. Xu Q F,Qian X B,Gui Z Y.Effects of litter decomposition of different stands on soil properties.Journal of Zhejiang Forestry College,2008,15(1):27-31.(in Chinese with English abstract)
[21] 劉增文,高文俊,潘開(kāi)文,等.岷江上游不同樹(shù)種林地客土混合對(duì)土壤生物化學(xué)性質(zhì)和枯落葉分解的影響.生態(tài)學(xué)報(bào),2007,27(10):1201-1211. Liu Z W,Gao W J,Pan K W,et al.Influences of soil mixing of different forests on the biochemical characteristics and litter decomposition on upper reach of Minjiang River.Acta Ecologica Sinica,2007,27(10):1201-1211.(in Chinese with English abstract)
[22] 鄧艷,蔣忠誠(chéng),覃星銘,等.巖溶生態(tài)系統(tǒng)中不同植被枯落物對(duì)土壤理化性質(zhì)的影響及巖溶效應(yīng).生態(tài)學(xué)報(bào),2009,29(6):3307-3315. Deng Y,Jiang Z C,Qin X M,et al.Impacts of litter on physical and chemical soil properties and its karst effects on different forested Karst ecosystem.Acta Ecologica Sinica,2009,29(6):3307-3315.(in Chinese with English abstract)
[23] 汪思龍,黃志群,王清奎,等.凋落物的樹(shù)種多樣性與杉木人工林土壤生態(tài)功能.生態(tài)學(xué)報(bào),2005,3(1):102-113. Wang S L,Huang Z Q,Wang Q K,et al.Effects of species diversity of litter on the ecological functions of Cunninghamia lanceolata(Lamb.)Hook.plantation soil.Acta Ecologica Sinica,2005,3(1):102-113.(in Chinese with English abstract)
Effects of four typical plant community litter input on soil physical and chemical properties under the fenced condition in desert steppe.Journal of Zhejiang University(Agric.&Life Sci.),2015,41(1):101-110
Li Xuebin1*,Chen Lin1,F(xiàn)an Ruixia1,Wu Xiuling2,Xie Yingzhong1(1.Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwestern China of Ministry of Education,Ningxia University, Yinchuan 750021,China;2.Ningxia Agricultural Prospecting and Design Institute,Yinchuan 750001,China)
desert steppe;litter;soil physical and chemical properties
S 812.8;S 158.3
A
10.3785/j.issn.1008-9209.2014.03.121
國(guó)家自然科學(xué)基金資助項(xiàng)目(31260581);教育部科學(xué)技術(shù)研究項(xiàng)目(413060);國(guó)家重大基礎(chǔ)研究前期研究專項(xiàng)(2012CB723206).
李學(xué)斌,E-mail:lixuebin@nxu.edu.cn
2014 03 12;接受日期(Accepted):2014 11 20;
日期(Published online):2015 01 19
URL:http://www.cnki.net/kcms/detail/33.1247.S.20150119.1706.009.html