选取福建省长汀县朱溪流域与其所属的游屋圳子流域作为研究区,构建流域间的水文相似性评价指标,量化评估母流域与子流域之间的水文相似度.结果表明朱溪流域与游屋圳小流域的水文相似度为完全相似水平,可将游屋圳小流域模型参数应用于缺实测资料朱溪流域的水文模拟.

为阐明在南方花岗岩红壤侵蚀区植被恢复对稀土迁移的影响,探讨稀土迁移的植物阻控效应,本研究以空间序列代替时间序列法选取不同治理年限下的典型样地,深入剖析其稀土含量特征,旨在量化评估生态林草措施下不同治理年限内阻控稀土迁移的生态效应.结果表明,水土流失样地随着生态恢复年限的增加,植被覆盖度的提高,植物种类的丰富,水土流失地土壤环境得到了改善,表层稀土流失也呈现出下降的趋势;土壤-芒萁系统中,稀土元素生态富集系数Ax呈现出先增加后下降的趋势,说明了土壤中稀土含量的增加短期内促进了稀土元素向芒萁植物叶片的迁移.芒萁植物叶片优先富集土壤中的轻稀土元素,充分体现出超累积植物芒萁一定程度上可阻控稀土元素向下游迁移,有可能达到生物调控环境中稀土污染的目的.研究成果可为拓展南方红壤侵蚀区稀土迁移的生物阻控提供科学依据.

以长汀低效林改造治理地为研究对象,对该区进行植物群落调查和土壤微生物群落测定,分析其随治理时间的变化特征,研究结果表明:①随着治理年限不断增加,乔木层物种单一稳定,物种数量增加,灌木和草本层物种数量逐渐减少;乔木层生长状况随着治理时间增加有大幅提升,灌草层的生长状况与植物种类密切相关;随着治理时间的增加,群落垂直结构及优势种分化明显,马尾松和芒萁占据优势地位,群落趋于稳定状态.②土壤真菌、细菌群落丰度和多样性变化与治理时间关联性较低,更多与植被恢复状况及土壤生化性质有关.

为阐明在极度退化生态系统中不同土壤侵蚀强度崩岗的稀土含量特征,探讨阻控稀土迁移的生态恢复措施,选取福建省长汀县濯田镇黄泥坑崩岗群中3种不同侵蚀强度的崩岗样地,分析不同土壤侵蚀强度对崩岗样地土壤中稀土元素含量特征及水平迁移的影响.结果显示:强度侵蚀崩岗稀土含量最高值出现在沟道部位,中度和微度侵蚀崩岗稀土含量最高值出现在崩积区部位;同一土壤侵蚀强度下,崩岗与对照坡面不同部位土壤中稀土总量均达到显著性差异(P<0.05);稀土结合形态中以可交换态和残渣态占据绝对优势,且崩岗中可交换态稀土含量明显高于非崩岗坡面;芒萁生长地非根际土生物可给态平均含量为214.90 mg·kg-1,根际土生物可给态平均含量达231.78 mg·kg-1.研究结果表明随着崩岗土壤侵蚀强度的加深,稀土呈现出向下游迁移能力增强的趋势,应加强极度退化生态系统崩岗的生态恢复治理,减少表层土壤流失量,阻控稀土的水平迁移量.稀土超累积植物(芒萁)的生态恢复措施有利于促进土壤中稀土元素向芒萁的迁移、累积,一定程度上可阻控稀土的水平迁移,从而降低潜在的生态风险水平.研究成果可为拓展崩岗稀土阻控的生态恢复治理提供科学依据.

以福建省连城县文坊稀土废弃矿区为研究对象,并以周围未开采区为对照,对其0～100 cm的土壤和地表水体的环境特征进行分析,探讨离子吸附型稀土开采对土壤和水体的影响.结果表明,全氮和有机碳含量偏高,土壤中铵态氮、硝态氮含量远高于未开采区,铵态氮是氮化物的主要存在形式;地表水体的NH4+-N、NO2-N、NO3-N、SO4 2-含量均高于对照区水体,NH4+含量接近国家地表水环境质量标准(GB 3838-2002)中Ⅲ类水限值;矿区土壤铵态氮、全氮和有机碳含量随着土壤加深而减少,硝态氮变化趋势相反.研究认为,虽经过多年淋失,但土壤和地表水体各项环境质量指标仍偏高,存在生态风险,本研究可为离子吸附型稀土废弃矿区环境修复提供参考.

为了解黑莎草(Gahnia tristis)在南方红壤侵蚀区的适应状况,测定了长汀县红壤侵蚀区的黑莎草叶片、根系的功能性状及土壤理化性质,并应用数理统计方法分析了黑莎草叶片与根系功能性状之间的相关性,及其对土壤因子的响应.结果表明,黑莎草叶片表型性状在冬夏季间存在显著差异,叶长、叶宽、叶组织密度和叶绿素表现为夏季显著大于冬季,根系表型性状则更具稳定性,冬季的根系养分含量均高于夏季,养分的分配上叶片养分高于根系养分.叶组织密度与叶绿素含量呈显著正相关,与比叶面积呈显著负相关;根组织密度与比根长和比根面积均呈显著负相关,叶片和根系养分间均呈显著正相关,土壤碳、氮、磷含量是影响黑莎草功能性状主要因子.因此,黑莎草可通过调节功能性状以适应环境变化,可作为地带性植物应用于南方红壤侵蚀区的植被恢复和水土流失治理.

为揭示在植被自然恢复过程中崩岗系统的生态恢复效应以及植物对于恶劣环境的适应机制,选取福建省长汀县濯田镇黄泥坑崩岗群的3种不同活动状况崩岗样地,应用生态化学计量学方法分析了其崩壁部位土壤养分和芒萁植物养分含量的变化特征及相关性.结果表明:同一活动状况崩岗崩壁不同部位土壤养分普遍达到显著性差异(p<0.05);不同活动状况崩岗崩壁土壤肥力有所提升,均在崩岗Ⅲ(稳定型)达最大值,但土壤有机碳、全氮、全磷含量仅有3.88,0.44,0.06 g/kg,远远低于全国土壤养分平均含量.崩壁芒萁三大营养器官的C,N,P普遍存在显著差异(p<0.05),但其体内养分含量与土壤表层中养分含量的相关性不大.可见,随着地表植被覆盖提高,崩岗的活动状况逐渐稳定,崩壁土壤养分含量有所增加,仍处于极度低下水平.芒萁植物受土壤养分的影响较小,能通过调节自身的养分适应贫瘠的恶劣生境,可作为改善南方红壤侵蚀区崩岗系统土壤肥力的重要措施.

为阐明在极度退化生态系统中崩岗植物体与土壤环境的养分循环及限制状况,笔者应用生态化学计量学方法对福建省长汀县濯田镇黄泥坑崩岗群中3种不同活动状况典型崩岗植物体-土壤的碳氮磷生态化学计量特征及相关性进行研究.结果 表明:崩岗活动状况对土壤养分有着重要的影响,崩岗系统在自然恢复过程中,随着崩岗稳定性增强,有利于改良土壤肥力,但仍处于极度低下水平.崩岗区由于其生态系统的极度退化特征,土壤肥力低下,其植物体化学计量特征主要与植物种本身的特性密切相关,受土壤养分的影响差异不显著,体现崩岗植物对极度退化生态系统环境的适应性.

崩岗是我国南方红壤丘陵山区坡面沟道侵蚀后期发育而成的侵蚀地貌,探讨崩岗系统植被恢复过程中不同部位土壤性质分异特征,对揭示强度侵蚀环境下土壤环境效应以及指导崩岗区生态恢复具有重要借鉴意义.以闽西南长汀县濯田镇黄泥坑崩岗群内植被盖度分别为2％、20％和95％的3处毗邻崩岗为研究对象,研究各崩岗集水坡面、崩壁(顶部、中部及底部)、崩积体(上部和下部)和沟道出口等部位0-20 cm土壤理化性质的分异特征.结果表明:土壤容重、粉粒、pH、速效养分含量均表现为崩岗Ⅲ＜崩岗Ⅱ≈崩岗Ⅰ,土壤有机碳、全氮、全磷和全钾含量表现为崩岗Ⅲ＞崩岗Ⅱ≈崩岗Ⅰ.从集水坡面至沟道出口,土壤容重和砂粒含量呈增加→减少→增加趋势,粉粒和黏粒含量呈降低变化趋势,集水坡面和崩积体有机碳、全氮、全磷和全钾含量明显高于其他部位,在崩壁顶部及沟道出口最低.从集水坡面至沟道出口,铵态氮和硝态氮含量呈先增加后减少的态势,速效钾含量呈“V”型变化态势,最低值出现在崩壁底部,速效磷和pH呈增加态势.本研究表明,崩岗系统内土壤结构和土壤养分含量总体水平较差,不同侵蚀部位土壤性质存在明显空间差异,自然植被恢复过程对土壤特性有一定的改良效应.

Collapsing hill and gully as a representative erosion type of granitic low hill region in Southern China,its geochemical elements were redistributed while a large number of sediments were taken away with erosion process. In this study,three collapsing hill and gullys which had vegetation coverage of 2%,20%,90% respectively and an adjacent hillside without collapsing hill and gully as contrast region(CK) were selected as the research object in Huangniken collapsing hill and gully group,Changting County,southwest of Fujian Province. The sample points were distributed in the different part of collapsing hill and gully system which included catchment slope,collapsing hill and gully wall,collapsing body and gully-alluvial. The contents of Ti,Zr and Y which are inert elements and their correlation with soil physical properties analyzed and,were the spatial distribution characteristics of Ti,Zr,Y in collapsing hill and gully system were discussed. The results indicated that:1) The content of Ti,Zr,Y represented the property of Ti>Zr>Y,and their contents increased with the vegetation coverage increasing(B1<B2<B3); The content of Ti,Zr,Y in B3 exceed that of B1 and B2. 2) Ti,Zr,Y all occurred redistribution under the effect of Collapsing hill and gully erosion; the Ti content of three Collapsing hill and gullys with different vegetation coverage was significantly lower than the CK,Ti has a tendency to homogenize,Zr and Y were accumulated in gully-alluvial;3) The contents of Ti,Zr,Y were significantly related with pH,OM content. Zr and Y are closely related.

不同植被覆盖度土壤氮素含量变化规律的研究可作为评价生态退化区植被恢复的指标之一.以福建省长汀县濯田镇黄泥坑崩岗群中三种不同植被覆盖度的毗邻崩岗为研究对象,比较其氮素含量的变化及不同部位氮素含量的变化规律.结果表明:植被覆盖度的提高能有效地减少土壤侵蚀,且与土壤的全氮含量及各部位的全氮含量均达到显著正相关,但同时也会增加硝态氮和铵态氮的流失,从而导致土壤中硝态氮、铵态氮的含量反而减少.而这三种不同植被覆盖度崩岗的全氮含量最高值均出现在集水坡面部位.与裸露崩岗和低覆盖崩岗不同的是,高覆盖崩岗的硝态氮与铵态氮的最大值也均出现在集水坡面部位.

【Objective】This study was done to elucidate C, N and P distributions in soil aggregates and their stoichiometric characteristics in eroded red soil under vegetation restoration relative to history of the restoration. 【Method】Six sample plots were set up on slope lands of typical eroded red soil under vegetation restoration with different restoration history（0, 5, 10, 15, 30 and 80 years） located in Hetian Town, Changting County, Fujian Province of Subtropical China. Soil samples were collected from different soil layers（0;0 cm and 20;0 cm） of the six plots for analysis of contents of organic carbon, total nitrogen, total phosphorus in soil aggregates different in particle size（>5 mm, 2; mm, 0.5; mm, 1; mm, 0.25; mm and <0.25 mm）. 【Result】 Results show that the contents of organic carbon, total nitrogen, total phosphorus in soil aggregates varied in the range of 2.06;7.71 g·kg;, 0.54;.12 g·kg; and 0.034;.189 g·kg;, respectively, and C︰N, C︰P and N︰P did in the range of 3.06;3.05, 21.4;85.6 and 5.62;8.20, respectively. On the whole the contents of organic carbon, total nitrogen, total phosphorus and C︰N increased in all fractions of soil aggregates in both soil layers with the restoration going on（P<0.05）, and the trend was more significant in the 0;0 cm soil layer than in the 20;0 cm layer, while soil C︰P and N︰P displayed a rising-falling-rising trend, and C︰P deceased with soil depth, and N︰P did not vary much. The contents of organic carbon, total nitrogen and total phosphorus, and C︰N and C︰P on the whole increased with the aggregates going down in particle size（P<0.05）, except for the plot of 0 year, while N︰P did not vary much with aggregate particle size（P>0.05）. The content organic carbon, total nitrogen and total phosphorus in soil aggregates were remarkably positively related to their respective ones in the soil. In the soil aggregates the contents of organic carbon and total N positively related to C︰N, the content of organic carbon was to C︰P, and the content of total phosphorus was to N︰P. 【Conclusion】All the findings in the study demonstrate that vegetation restoration mitigates soil erosion and significantly increases the contents of organic carbon, total nitrogen and total phosphorus and improves the function of soil aggregates as carbon and nitrogen pools, and what is more, P in the aggregates is the major factor restraining rehabilitation of the degraded ecosystem.

崩岗是南方红壤区侵蚀沟在水力和重力交互作用下沟头遭受坍塌、陷蚀作用而形成的围椅状地貌,是该区域土壤侵蚀及生态系统退化的最高表现形式之一.为揭示崩岗侵蚀对土壤理化特性及可蚀性的影响,以福建省长汀县濯田镇黄泥坑崩岗群内植被盖度分别为2％,20％,95％的3个典型崩岗为研究对象,分别对崩岗系统内的集水坡面、崩壁、崩积体和沟口进行采样和理化特性的测定,并运用EPIC模型测算土壤可蚀性(K).结果表明:1)从集水坡面到崩壁、崩积体至沟口,3个崩岗的土壤砂粒质量分数、pH值和土壤密度呈升高趋势,粉粒、砂粒的质量分数和含水量呈下降趋势.2)1号和2号崩岗,集水坡面的土壤有机质质量分数最高,在崩壁最低;3号崩岗土壤有机质质量分数在崩壁处急剧下降,在崩积体中又明显上升.3)各崩岗中集水坡面、崩壁和崩积体的土壤颗粒组成、土壤密度和含水量差异较小,各土壤理化特性指标在沟口与集水坡面、崩壁和崩积体之间存在显著差异.4)崩岗系统内的集水坡面、崩壁、崩积体和沟口4个子系统的K值差异显著,1、2号崩岗呈现崩壁＞崩积体＞沟口＞集水坡面的变化规律,而3号崩岗则表现为沟口＞崩积体＞崩壁＞集水坡面的趋势.5)崩岗系统内的黏粒质量分数、pH值和有机质质量分数与土壤可蚀性关系密切,可以作为表征崩岗土壤可蚀性的有效指标.崩岗侵蚀造成土壤理化特性不断恶化,砂化严重,研究崩岗系统的土壤理化特性与可蚀性空间变化规律,对指导崩岗的恢复与重建具有重要意义.

为深入了解不同植被恢复年限下土壤团聚体养分分布特征,以典型红壤侵蚀区福建省长汀县河田地区恢复年限分别为0,5,10,15,30,80 a的坡地土壤为研究对象,分别对0-20 cm和20-40 cm土层不同粒径团聚体养分含量进行测定,并分析了它们与不同团聚体的相关关系.结果表明:(1)植被恢复过程中,土壤团聚体有机碳、全氮、全磷、全钾、速效磷和速效钾含量的变化范围分别为2.06～27.71 g/kg,0.54～2.12 g/kg,0.034～0.171 g/kg,2.20～6.89 g/kg,0.31～3.30 mg/kg和7.35～85.71g/kg;(2)有机碳、全氮、全磷和速效磷含量随着团聚体粒径的减小总体上表现出显著升高趋势(P＜0.05),全钾和速效钾含量无明显差异(P＞0.05);(3)随植被恢复年限增加,各粒径团聚体中有机碳、全氮、全磷、速效磷含量总体上呈显著升高趋势(P＜0.05),全钾含量先升高后降低,而速效钾含量表现出波动增加趋势;(4)恢复初期(0 a和5 a)不同土层间团聚体养分含量无明显变化(P＞0.05),其它恢复年限0-20 cm土层团聚体有机碳、全氮、全磷、速效磷和速效钾含量显著高于20-40 cm土层(P＜0.05);(5)团聚体对土壤养分的贡献率表现为(＞5 mm)＞(2～5 mm)＞(0.5～1 mm)＞(1～2 mm)＞(0.25～0.5 mm)＞(＜0.25 mm),＞2 mm粒径养分贡献率达34.18％～49.93％,土壤养分含量与＞0.25 mm粒径相关性较强(P＜0.01).植被恢复在降低土壤侵蚀的同时,土壤团聚体养分含量明显增加,土壤结构得以改善,养分固持能力得到加强.

[Background] Collapse mound,called "Benggang"in Chinese geomorphic pictograph,has been known to describe a kind of erosion phenomenon in hilly and mountainous area among subtropical and fractional tropical climatic zone of south China that gully head collapsed,transported and developed a deep-cut shape,concave-deforming deep-seated failure landform. [Methods] To reveal the effects of collapse mound erosion on soil available nutrients and stoichiometry ratios,we chose 3 collapse mounds of slight,moderate and strong erosion intensities in Huangniken collapse mound groups of Changting County of Southwest Fujian as research object. Soils at 0- 10 cm,10- 20 cm and 20- 30 cm in 4 positions of upper catchment,collapsing wall,colluvial deposit and channel were sampled,and the contents ofammonium N( NH+4-N),nitrate N( NO-3-N),available P( AP) and available K( AK) and related physical-chemical properties,such as mechanical composition,bulk density,water content,and organic matter content were measured,finally,the stoichiometric characteristics of available nutrients were analyzed. [Results] The results indicated that: 1) With erosion intensity increasing,the contents of NO-3-N and AP occurred in the collapse mound of strong > moderate > slight,and the content of NH+4-N was the lowest and AK was the highest in collapse mound under moderate erosion; horizontally,the diminishing order of contents of soil available nutrients were displayed as following: AK > NH+4-N >NO-3-N > AP,while the content of each available nutrient decreased vertically as soil depth increasing,and their variance of the same erosion intensity was very little. 2) With different erosion intensities,AN( NH+4-N + NO-3-N) / AP ratio showed: slight > moderate > strong, and there was significant difference( P < 0. 05) between slight and moderate collapse mound; AK / AN ratio was in moderate >slight > strong,and there was significant difference( P < 0. 05) between moderate and strong collapse mound; AK / AP ratio was in slight > strong > moderate,and difference was significant( P < 0. 05)between slight and moderate. 3) From upper catchment,collapsing wall,colluvial deposit and channel,the averaged content of NH+4-N and NO-3-N showed a downward tendency, while AP increased gradually,and AK was the lowest at colluvial deposit,but in 3 other sections they varied slightly under different erosion intensities; meanwhile,AN / AP and AK / AP ratios decreased from slope of catchment area to channel,but the value of AK / AN ratio was the highest at channel. 4) Stoichiometric ratios of soil available nutrients were closely correlated to sand,silt,p H value and organic matter,but they were impacted slightly by the clay,bulk density and water content. [Conclusions] collapse mound erosion resulted in variation of soil available nutrients and stoichiometry ratios with different layers and position.

Benggang(collapsed hill)is the most serious type of soil erosion in subtropical zone of south China. The speed and intensity of its development have a great impact on the surface of the earth, and it has an important influence on the content and distribution of the Rare Earth Element(REE)in soil. Via field sampling and laboratory test by ICP-MS determination, collapse erosion of three different groups in different parts topsoil(0-10cm)were sampled within the Huangnikeng,Zhuotian town Changting county Fujian province. The results show that contents of REE were slight erosion zone > moderate erosion zone> intensity erosion zone, and Light Rare Earth Element(LREE)is rich; REE content in different conditions basically show gradual increasing trend of erosion along the catchment to the channel; Ce element is rich in content and Eu element is low in content; REE content is rich in surface soil of vegetation coverage area.

以福建省西南部长汀县濯田镇黄泥坑崩岗群内植被盖度分别为2%,20%和95%的3处相邻崩岗为研究对象,对各崩岗内集水坡面、崩壁（顶部、中部及底部）、崩积体（上部和下部）和沟道出口7个典型部位0—10,10—20,20—30cm土壤基本理化性质进行测定,分析了各植被盖度崩岗不同深度及部位土壤化学计量比的空间分异规律。结果表明:随着植被盖度的升高,土壤养分含量及化学计量比显著增加（除全磷含量和P/K以外）;随着土壤深度的增加,有机碳、全氮和全钾含量以及C/N、C/P、C/K和N/P总体上呈减少趋势,全磷含量以及N/K和P/K基本维持稳定;沿集水坡面→崩壁→崩积体→沟道出口,有机碳、全氮和全钾含量以及C/N、C/P、C/K、N/P和N/K基本表现为先减少再增加最后亦降低的变化趋势,全磷含量和N/P无明显差异;土壤化学计量特征与土壤养分含量、粉粒含量、容重、含水量和pH具有较强的相关关系。崩岗系统土壤物理结构较差,养分含量普遍较低,其中有机碳、全氮和全磷含量存在不同程度的限制。