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1.
巨桉人工林中小型土壤动物类群分布规律   总被引:10,自引:0,他引:10  
黄玉梅  张健  杨万勤 《应用生态学报》2006,17(12):2327-2331
研究了四川省洪雅县巨桉人工林中小型土壤动物类群及数量分布规律.结果表明,巨桉人工林四季共获中小型土壤动物13 550头,分属6门13纲26目,以蜱螨目、线虫纲、弹尾目为优势类群,以线蚓科为常见类群.各样地中小型土壤动物类群数、个体数均有明显季节变化,以秋季或冬季最高,春季最低,夏季次之.中小型土壤动物密度剖面分布表聚性明显,但在5~10 cm和10~15 cm土层间有时会出现逆向分布现象.中小型湿生土壤动物密度为3.333×103~2.533×105个·m-2,中小型干生土壤动物密度为1.670×102~2.393×105个·m-2,中小型湿生土壤动物密度自上而下减少的速率小于中小型干生土壤动物.巨桉人工林中小型土壤动物密度-类群(DG)指数以春季最低,秋季或夏季最高(可达6.637).巨桉人工林与青冈次生林中小型土壤动物密度及DG指数均无显著差异.  相似文献   

2.
基于HNSOTER的海南岛土壤有机碳储量及空间分布特征分析   总被引:6,自引:0,他引:6  
基于海南岛1∶200 000土壤 地体数字化数据库(HNSOTER),在GIS系统的支持下,对海南岛土壤有机碳储量及分布特征进行了探讨.结果表明,1)标准剖深下(0~100 cm),海南岛土壤有机碳储量为2.78×108 t.2)0~20 cm剖深土壤有机碳密度变幅在0.3~18.8 kg·m-2之间,其中1.0~5.0 kg·m-2密度区占总分布面积的81.2%,按面积加权均值为3.3 kg·m-2.0~100 cm剖深的土壤有机碳密度变幅在1.0~32.1 kg·m-2 之间,其中2.0~14.0 kg·m-2密度区面积比重占89.7%,按面积加权均值为8.4 kg·m-2.不同地形、岩性及土壤类型中,土壤有机碳密度分布有较大变异.3)从中部山地向外至沿海平原,土壤有机碳密度总体上呈递减趋势,但不同剖深下其分布格局仍有一定差异.0~20 cm剖深下土壤有机碳密度高值区(丰富度指数大于1)主要分布于山地以及北部玄武岩台地,0~100 cm剖深下,有机碳密度高值区(丰富度指数大于1)趋向集中于中东部山地、台地区,且其分布重心较前者明显的向东偏移.  相似文献   

3.
Simulated raindrops, diameter c. 3 or 4 mm, fell 13 m down a raintower onto suspensions of Septoria nodorum pycnidiospores, depth 0.5 mm, or infected straw pieces. Splash droplets were collected on pieces of fixed photographic film. It was estimated that one drop generated c. 300 spore carrying splash droplets, containing c. 6000 spores, from a concentrated spore suspension (6.5 × 105 spores/ml) and c. 25 spore-carrying droplets, containing c. 30 spores, from infected straw pieces (11 × 106 spores/g dry wt). When the target was a spore suspension in water without surfactant, most spore-carrying droplets were in the 200—400 μm size category and most spores were carried in droplets with diameter >1000 μm. When surfactant was added to spore suspensions, most spore-carrying droplets were in the 0–200 μm category and most spores were carried in droplets with diameter 200–400 μm and none in droplets >1000 μm. Regression analyses showed a significant (p < 0.001) relationship between square root (number of spores per droplet) and droplet diameter; the slope of the regression line was greatest when surfactant was added to the spore suspensions. The distribution of splash droplets with distance travelled from the target was better fitted by an exponential model than by power law or Gaussian models. The distributions of spore-carrying droplets and spores with distance were fitted better by an exponential model than by a power law model. Thus regressions of log, (number collected) against distance were all significant (p < 0.01); the slopes of the regression lines were steepest when surfactant was added to the spore suspension. At a distance of 10 cm from target spore suspensions most splash droplets and spore-carrying droplets were collected at height 10–20 cm, with none above 40 cm; at a distance of 20 cm there were most at heights 0–10 cm and 40–50 cm.  相似文献   

4.
Plasma Physics Reports - Edge ignition of a cylindrical shell target by a proton beam with a small mass heating depth of about 0.5 g/cm2 is analyzed for two values of the initial mass density of...  相似文献   

5.
保护性耕作对紫色水稻土团聚体组成和有机碳储量的影响   总被引:12,自引:0,他引:12  
通过长期定位试验,研究了保护性耕作对四川盆地紫色水稻土耕层团聚体组成和有机碳储量的影响.结果表明,保护性耕作显著影响耕层团聚体组成及其有机碳含量.油菜免耕、厢作免耕、绿肥免耕、垄作翻耕和厢作翻耕0~10 cm土壤大团聚体分别比对照(12%)增加23%、69%、9%、36%和28%,而10~20 cm土壤大团聚体比对照低9%~38%.冬水免耕、油菜免耕和绿肥免耕0~10 cm土壤大团聚体中有机碳含量分别比对照增加13%、31%和32%,而10~20 cm土壤各处理有机碳含量低于对照28%~54%,其土壤大团聚体和微团聚体中碳浓度差异低于0~10cm土壤.各处理0~10 cm土壤总有机碳储量比对照增加8%~28%,而10~20 cm土壤总有机碳储量低于对照4%~22%.传统耕作转变为保护性耕作13年后0~10和10~20 cm土壤有机碳固定率分别为53和25 g·m-2·a-1,传统耕作有机碳固定率分别为26和33 g·m-2·a-1.保护性耕作有利于紫色水稻土表层大团聚体的形成和土壤总有机碳储量的提高.  相似文献   

6.
三江平原典型湿地土壤剖面有机碳及全氮分布与积累特征   总被引:9,自引:0,他引:9  
研究了三江平原2类典型湿地(毛果苔草沼泽和芦苇沼泽)沉积物剖面有机碳、全氮的分布特征与积累现状.结果表明,2类沼泽剖面有机碳分布均具有明显的储碳层和淀积层;上层的储碳层厚度约为60 cm,有机碳平均含量分别为96和184 g·kg-1,全氮平均含量分别为7.4和17.6 g·kg-1;下层的淀积层内有机碳和全氮含量低而稳定.2类沼泽剖面有机碳和全氮含量随剖面深度增加而下降, 有机碳、全氮与容重之间相关均极显著(P<0.01).2类典型湿地有机碳密度在20~40 cm剖面内最大.储碳层内,有机碳储量分别为1.83×104和1.73×104 t·km-2,全氮储量分别为1.45×103和1.67×103 t·km-2;100 cm以内,有机碳储量分别为2.86×104和262×104 t·km-2,全氮储量分别为2.18×103和2.49×103 t·km-2.植被类型对湿地剖面有机碳、全氮含量及储量均具有不同程度的影响.  相似文献   

7.
Dispersal of Septoria nodorum Pycnidiospores by Simulated Rain and Wind   总被引:2,自引:0,他引:2  
The influence of wind on the splash dispersal of Septoria nodorum pycnidiospores was studied in a raintower/wind tunnel complex with single drops or simulated rain falling on spore suspensions or infected stubble with windspeeds of 1.5 to 4 m/sec. When single drops fell on spore suspensions (depth 0.5 mm, concentration 7.8 × 105 spores/ml) most of the spore-carrying droplets collected on fixed photographic film between 0–4 m downwind (windspeed 3 m/sec) were >200 μm in diameter. However, most spores were carried in droplets with diameter > 1000 μm, 70 % of which carried more than 100 spores. When simulated rain fell on infected stubble most of the spore-carrying droplets collected beyond 1 m downwind (windspeeds 1.4 and 4 m/sec) were <200 μm in diameter and none were >600 μm; most of these droplets carried only one spore. The distribution of splash droplets (with diameter >100 μm) deposited on chromatography paper showed a maximum at 40–50 cm upwind of the target but many more droplets were deposited 20–30 cm downwind, when single drops fell on a spore suspension (concentration 1.2 × 105 spores/ ml) containing fluorescein dye with a windspeed of 2 m/sec; droplets were collected up to 3 m downwind but not more than 70 cm upwind. With a windspeed of 3 m/sec, numbers of sporecarrying droplets and spores collected on film decreased with increasing distance downwind; most were collected within 2 m of the target but some were found up to 4 m. When simulated rain fell on infected stubble, increasing the windspeed from 1.5 to 4 m/sec greatly increased the number of spores deposited more than 1 m downwind. At 1.5 m/sec none were collected beyond 2 m downwind, whereas at 4 m/sec some were collected at 4 m. A few air-borne S. nodorum spores were collected by suction samplers at a height of 40 cm at distances up to 10 m downwind of a target spore suspension on which simulated rain fell.  相似文献   

8.
沙冬青群落土壤有机碳和全氮含量的空间异质性   总被引:6,自引:0,他引:6  
应用地统计学的基本原理与方法,分析了干旱荒漠地带沙冬青群落0~5和50~70 cm土壤有机碳(SOC)和全氮(TN)及C/N空间异质性.结果表明,0~5 cm的SOC和TN的平均含量分别为0.744和0259 g·kg-1,平均变异系数分别为0.280和0.213; 50~70 cm的SOC和TN的平均含量分别为1.425和0.295 g·kg-1,平均变异系数分别为0.195和0.206,反映出该植被区土壤肥力较为贫瘠.该沙生植被区土壤SOC和TN含量存在高度空间异质性,其空间异质性主要由自相关因素引起.0~5 cm土层 SOC和TN含量空间变异尺度分别为20.99和29.19 m;50~70 cm土层分别为42.9和62.1 m.变异尺度未集中在沙冬青冠幅范围,未反映出荒漠地带沙生植物种的“肥岛”效应,为其他物种的入侵创造了障碍.这种空间分布格局和尺度为维持沙冬青在干旱荒漠沙生植被区的优势度提供了保障,解释了其长期存在的机制.  相似文献   

9.
A field experiment was conducted on a Vertisol for three consecutive years (1998-2000) to study the effects of combined use of inorganic fertilizer (NPK) and organic manure (farmyard manure) on soil physical properties, water-use efficiency, root growth and yield of soybean [Glycine max (L.) Merr.] in a soybean-mustard cropping system. Application of 10 Mg farmyard manure and recommended NPK (NPK+FYM) to soybean for three consecutive years improved the organic carbon content of the surface (0-15 cm) soil from an initial value of 4.4 g kg(-1) to 6.2 g kg(-1) and also increased seed yield and water-use efficiency by 103% and 76%, respectively, over the control. The surface (0-15 cm) soil of the plots receiving both farmyard manure and recommended NPK had larger mean weight diameter (0.50 mm) and a higher percentage of water stable aggregates (55%) than both the inorganically fertilized (NPK) (0.44 mm and 49%) and unfertilized control plots (0.41 mm and 45.4%). The saturated hydraulic conductivity (13.32 x 10(-6) m s(-1)) of the NPK+FYM treatment of the 0-7.5 cm depth was also significantly greater than that of the NPK (10.53 x 10(-6) m s(-1)) and control (8.61 x 10(-6) m s(-1)) treatments. The lowest bulk density (1.18 Mg m(-3)) in the 0-7.5 cm layer was recorded in NPK+FYM whereas it was highest in the control plots (1.30 Mg m(-3)). However, at sub-surface (22.5-30 cm) layer, fertilizer and manure application had little effect on bulk density and saturated hydraulic conductivity. Root length density (RLD) up to the 30 cm depth was highest in the NPK+FYM plots and it was 31.9% and 70.5% more than NPK and control plots. The RLD showed a significant and negative correlation (r=-0.88( * *)) with the penetration resistance.  相似文献   

10.
互花米草入侵对大型底栖动物群落垂直结构的影响   总被引:1,自引:0,他引:1  
2012年8月,在浙江省玉环县漩门湾国家湿地公园,利用自制分层采样器,以5 cm为单位对0—25 cm泥层进行分层取样,研究潮间带互花米草滩涂和自然滩涂两种生境中大型底栖动物的垂直分布情况,以及互花米草入侵对大型底栖动物垂直结构的影响。两种生境中共获得大型底栖动物40种,其中软体动物18种,甲壳动物13种,环节动物4种,其他类群5种。在自然滩涂生境中获得的物种数为30种,互花米草生境为31种,两种生境的共有种有21种。互花米草和自然滩涂生境平均栖息密度分别为222.6株/m2和1052.8株/m2。研究结果表明:(1)大型底栖动物主要栖息在0—10 cm泥层深度;(2)大型底栖动物群落沿泥层深度存在分层分布现象;(3)互花米草入侵缩短了底栖动物的垂直分布距离,但对其主要栖息深度影响不大;(4)互花米草入侵改变了原来生境特征,导致大型底栖动物的群落结构发生变化。  相似文献   

11.
Tu LH  Dai HZ  Hu TX  Zhang J  Luo SH 《应用生态学报》2011,22(4):829-836
From January 2008 to February 2009, a field experiment was conducted in Rainy Area of West China to understand the effects of nitrogen (N) deposition on the soil respiration in a Bambusa pervariabilis x Dendrocala mopsi plantation. Four treatments were installed, i. e., no N added (control), 5 g N m(-2) a(-1) (low-N), 15 g N m(-2) a(-1) (medium-N), and 30 g N m(-2) a(-1) (high-N), and soil respiration rate was determined by infra-red CO2 analyzer. In the plantation, soil respiration rate had an obvious seasonal change, with the maximum in July and the minimum in January. In control plot, the annual cumulative soil respiration was (389 +/- 34) g m(-2) a(-1). Soil respiration rate had significant positive exponential relationships with soil temperature at 10 cm depth and air temperature, and significant positive linear relationships with soil microbial biomass carbon (MBC) and nitrogen (MBN). Simulated N deposition promoted soil respiration significantly, with significant differences between the low- and medium-N and the control but no significant difference between high-N and the control. In control plot, surface soil (0-20 cm) MBC and MBN were 0.460 and 0.020 mg g(-1), respectively. In N-added plots, both the MBC and the MBN had significant increase. The fine root density in surface soil was 388 g m(-2), which was less affected by simulated N deposition. The soil respiration Q10 value calculated from soil temperature at 10 cm depth and air temperature was 2.66 and 1.87, respectively, and short-term N deposition had lesser effects on the Q10 value. The variation of soil respiration in the plantation was mainly controlled by temperature and soil microbial biomass, and simulated N deposition could increase the CO2 emission via increasing soil microbial biomass.  相似文献   

12.
The solution properties of a variety of different sapid substances from all four basic taste modalities, namely, sweet (n = 24), salty (n = 7), sour (n = 11) and bitter (n = 2), have been investigated. Some multisapophoric molecules, i.e. molecules exhibiting more than one taste, have also been included in the study in an attempt to define their properties in relation to the tastes they exhibit; eight sweet-bitter and three salty-bitter molecules were used. The density and sound velocity of their solutions in water have been measured and their apparent volumes, apparent compressibilities and compressibility hydration numbers calculated and compared. Apparent molar volumes (phi(v)) and apparent specific volumes (ASV) reflect the state of hydration of the molecules, and thus their extent of interaction with water structure. The range of ASVs reported are 0.13-0.49 cm3/g for salty molecules, 0.55-0.68 cm3/g for sweet molecules, 0.53-0.88 cm3/g for sweet-bitter molecules and a much wider range (0.16-0.85 cm3/g) for sour molecules. Isentropic apparent specific compressibilities range from -2.33 x 10(-5) to -8.06 x 10(-5) cm3/g x bar for salty molecules, -3.38 x 10(-7) to -2.34 x 10(-5) cm3/g x bar for sweet molecules, +6.35 x 10(-6) to -2.22 x 10(-5) cm3/g x bar for sweet-bitter molecules and +6.131 x 10(-6) to -2.99 x 10(-5) cm3/g x bar for sour molecules. Compressibility hydration numbers are also determinable from the measurements of isentropic compressibilities and these reflect the number of water molecules that are disturbed by the presence of the solutes in solution. This study also shows that it is possible to group isentropic apparent molar compressibility values by the taste quality exhibited by the molecules in the same order as for ASV.  相似文献   

13.
膜-生物硝化反应器处理含氨废水效能的研究   总被引:1,自引:0,他引:1  
武小鹰  郑平  胡宝兰   《生物工程学报》2005,21(2):279-283
研究了膜 生物硝化反应器对含氨废水的处理效能以及分离膜的截留和渗透效能。膜_生物反应器启动迅速 ,在水力停留时间为 1d的情况下 ,反应器最高进水浓度达 80mmol(NH4+-N)·L-1 ,最高容积负荷达 1 12kg(NH4+ -N)·m-3·d-1 ,氨氮去除率保持在 95%以上。试验证明 ,分离膜对微生物有良好的截留作用 ,50天内反应器的污泥浓度从 5g·L-1 增长到 10g·L-1 ,分离膜表面附着的生物层则对废水氨氮和亚硝氮有进一步的转化作用。在液位差低于 80cm时 ,提高液位差可增大膜渗透通量 ;液位差超过 80cm后 ,增大液位差的膜渗透通量效应很小 ;其中 ,当液位差为 2 0cm左右时 ,膜通量达 2 . 5 1L·m-2 ·h-1 ,阻力最小 [(2 . 6 3× 10-5)m-1]。该膜_生物硝化反应器可依靠液位差压力驱动出水 ,无需外加动力。  相似文献   

14.
长白山北坡阔叶红松林和暗针叶林的土壤水分物理性质   总被引:16,自引:1,他引:16  
对长白山北坡阔叶红松林和暗针叶林的土壤水分物理性质进行了观测和对比分析.结果表明:两种森林类型的土壤容重和各种孔隙度随土壤深度的变化趋势相同,即随着土壤深度的增加,容重和毛管孔隙度逐渐增加,总孔隙度和非毛管孔隙度逐渐降低;两种森林类型土壤物理性质的差异比较明显,阔叶红松林0~100 cm土层的平均土壤容重、总孔隙度、毛管孔隙度和非毛管孔隙度分别为1.41 g·cm-3、52.31%、46.11%和6.20%,暗针叶林地土壤分别为0.98 g·cm-3、50.65%、40.32%和10.33%;阔叶红松林和暗针叶林地土壤100 cm土层贮水能力相差较大,分别为619.89和1 033.05 t·hm-2.两种森林类型的土壤水分特征曲线与一般土壤水分特征曲线相一致.  相似文献   

15.
The properties of stDNA of three species of the subtribe Citrinae have been investigated. The buoyant density of the main component is 1.693 g/cm3, that of satellite component is 1.712 g/cm3 and 1.715 g/cm3. The differential melting curves of satellite components reveal two melting zones. Some of stDNAs are melted within a broad temperature range, while others--at higher temperatures as a narrow peak. The reassociation kinetics suggest that 50-54% of stDNA are a fast reassociating fraction with the length of repeating sequences of 0.8-1.1 x 10(2) base pairs. Based on the values of Tm and buoyant density the 5-methylcytosine content in stDNA was calculated and was found equal to 20-35%. Using equilibrium ultracentrifugation in the actinomycin D--CsCl density gradient the stDNAs of the subtribe Citrinae were separated into constituent components.  相似文献   

16.
缺苞箭竹群落密度对土壤养分库的影响   总被引:4,自引:0,他引:4  
研究了王朗自然保护区内缺苞箭竹(Fargesiadenudata)群落3个密度在1个生长季(5~10月)内不同土壤层次的养分贮量及其季节动态.结果表明,土壤(0~30cm)总P、速效P贮量均随密度的增加而显著减少(P<0.01);而土壤总Ca、Mg贮量则随密度的增加而增加;土壤N、K(全量或速效)贮量密度间差异不大.在不同密度的箭竹群落样地内,除了D1样地土壤总钾贮量大于Ca外,土壤层(0~30cm)不同养分贮量(全量)大小顺序均为Ca>K>Mg>N>P.表层(L1)速效N、P和K浓度在7月份均有显著降低的现象,随后又逐渐回升.养分的变化幅度则普遍存在着表层(L1)大于下层(L2、L3),高密度(D3)大于低密度(D1),速效P大于速效N、K的现象.土壤总养分贮量与浓度在土壤层次上的分布特征明显不同,3个密度样地中L1(0~10cm)层的N、P、K、Ca、Mg贮量均低于L2(10~20cm)和L3(20~30cm)层.分析表明,箭竹群落土壤层养分贮量与密度密切相关,可能是由于密度影响到了箭竹对土壤养分的吸收、凋落物养分的归还、微生物活性等养分循环各个环节,从而导致了土壤养分贮量的改变.其中,密度对P、Ca贮量影响最大,Mg其次,对N、K影响最弱.随着箭竹密度的增加,越来越低的土壤总P、速效P贮量也表明,P素可能是箭竹生长发育的主要限制因子,P不足可能是导致箭竹开花的重要诱因.  相似文献   

17.
Throughout their range, giant clams (family Tridacnidae) are increasingly threatened by anthropogenic impacts and natural disasters, but little is known about their population status. In this first assessment of the tridacnid population at Abu Sauatir in the northern Red Sea, a total of 491 m2 were surveyed and >200 clams recorded. Tridacna maxima was the only species found. The population's live:dead ratio was 3:1. Overall clam density was 0.08?±?0.008 live and 0.02?±?0.007 dead individuals per 0.25 m2. Greatest densities occurred on the reef flat in 1 m depth (live), and on the northern reef slope in deeper waters (dead). On the slope, live clam density decreased significantly, whereas dead clam density increased significantly with depth. Sizes of live and dead individuals differed significantly. Live clams ranged from 1 to 30 cm (median 5 cm). Juveniles ≤2 cm (8.2% of the population) and individuals >11 cm occurred on the reef slope but not on the reef flat. Live clam sizes did not differ significantly between reef sites. Dead clam size ranged from 2 to 15 cm (median 6.5 cm). 2.1% of the empty shells were ≤2 cm long. Dead clam sizes differed significantly between 5 and 10 m depth on the northern reef slope. The low clam abundance (live and dead) in the shallowest and most easily accessible areas of the reef flat, combined with small sizes, strongly suggest artisanal reef-top gathering for meat and shells.  相似文献   

18.
Abstract Soil temperatures down to a depth of 5 cm were measured in the days following one fire in summer, one fire in winter and in unburnt vegetation during summer. Soil temperatures did not rise above 40°C after the winter fire or in unburnt vegetation during summer. Consequently, no impact on seed dormancy in the soil seedbank was expected. After a summer fire, soil temperatures above 40°C were found up to 4.5 cm in depth, while temperatures above 60°C were found only in the top 0.5 cm of soil. These temperatures are sufficient to break seed dormancy in some legume species in the seedbank. Hence, the season of burn may influence the number of seeds in the soil that have their dormancy broken and subsequent germination levels.  相似文献   

19.
Polyclonal rabbit antisera raised against sulfate-reducing bacteria (SRB) could detect several distinct populations of bacteria in sediment from the German Baltic Sea. The depth distribution of immunoreactive bacteria was determined by an indirect immunofluorescence filter method. Anti-Desulfovibrio desulfuricans DSM 1926 serum showed maximum bacterial numbers at a depth of 18 cm, with a concentration of 60 x 10(6) cells cm-3. With anti-Desulfovibrio baculatus DSM 2555 serum, counts were highest at the same depth, approaching 0.7 x 10(6) cells cm-3. Other significantly smaller populations were observed. Anti-SRBStrain 1 (lactate,vibrio) maxima were at 0 to 4 cm and at 17 to 18 cm. Anti-SRBStrain 2 (lactate,vibrio) serum showed several local maxima. Anti-SRBStrain 3 (lactate,oval) serum detected one single peak at a depth of 10 to 12 cm. Also determined were rates of sulfate reduction, total bacterial counts by acridine orange staining, and the viable counts by dilution series on anaerobic lactate medium. The total bacterial counts were highest (180 x 10(6) cells cm-3) at 3 to 4 cm and dropped to 24 x 10(6) cells cm-3 at 10 to 11 cm but showed additional local maxima reaching 140 x 10(6) cells cm-3 at a depth of 17 to 18 cm. Viable counts probable number) were above 10(5) CFU cm-3 at 0 to 3.6 cm but remained below 10(3) CFU at 7.2 to 18 cm. The sulfate reduction rate was maximal (107 nmol cm-3 day-1) at a depth of 1 to 2 cm, dropped to 10 nmol cm-3 day-1 at 12 to 13 cm, and reached 38 nmol cm-3 day-1 at 17 to 18 cm.  相似文献   

20.
湿地土壤有机碳研究是全球碳循环研究的基础性工作, 对于准确评估湿地固碳增汇和全球温室气体减排都具有重要意义。以鄱阳湖国家自然保护区为研究区域, 选择六种景观类型(湿地洲滩景观包括受人工控制的碟形湖泊常湖池、半人工控制的碟形湖泊蚌湖、不受人工控制的洲滩前缘泗洲头以及岗地景观包括林地、田地和菜地), 湿地洲滩景观在各1 m高程(泗洲头和蚌湖采样高程10-17 m, 常湖池采样高程12-17 m)内的浅土壤采取3个土壤样品, 岗地景观浅层土壤各采取3个土壤样品, 分析浅层土壤有机碳含量。结果表明, 鄱阳湖不同景观类型的浅层土壤有机碳含量差异性显著。湿地洲滩浅层土壤(特别是0-10 cm土层)的有机碳随高程梯度变化呈现倒U型变化, 即低海拔与高海拔土壤有机碳的含量较中海拔土壤有机碳的含量低, 泗洲头洲滩土层0-10 cm的有机碳含量最高值出现在13-14 m高程, 其中0-10 cm土层的土壤有机碳含量变化值为1.56-12.29 g·kg-1, 10-20 cm土层的土壤有机碳含量变化值为0.96-8.19 g·kg-1; 蚌湖洲滩土层0-10 cm的有机碳含量最高值出现在14-15 m高程, 其中0-10 cm土层的土壤有机碳含量变化值为6.36-23.32 g·kg-1, 10-20 cm土层的土壤有机碳含量变化值为4.14-8.88 g·kg-1; 常湖池洲滩土层0-10 cm的有机碳含量最高值出现在16-17 m高程, 其中0-10 cm土层的土壤有机碳含量变化值为6.51-18.91 g·kg-1, 10-20 cm土层的土壤有机碳含量变化值为3.83-10.05 g·kg-1。岗地浅层土壤有机碳(特别是0-10 cm土层)田地的土壤有机碳含量最高, 菜地土壤有机碳含量最低。比较六种景观类型的浅层土壤有机碳含量, 泗洲头洲滩浅层土壤有机碳含量最低, 蚌湖洲滩浅层土壤有机碳含量最高。六种景观类型的浅层土壤有机碳含量呈现一致的现象是土层0-10 cm的机碳含量明显高于土层10-20 cm的有机碳含量, 说明鄱阳湖国家自然保护区内土壤有机碳含量主要富集在土壤浅层的特征。土壤pH值对湿地土壤有机碳呈显著负相关性, 而土壤含水量、地上部分生物量与土壤有机碳呈显著正相关性。  相似文献   

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