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1.
锡林浩特草原矿区土壤碳氮磷化学计量特征 总被引：3，自引：0，他引：3
为了解草原矿区土壤碳(C)、氮(N)、磷(P)含量及生态化学计量特征,以锡林浩特胜利煤田周围草原为研究对象,研究不同距离、不同方向土壤C、N、P含量及化学计量特征。结果表明:1)土壤有机碳、全氮、全磷含量在4.0km处最高,碳磷比(C/P)、氮磷比(N/P)在4.0km处最高,碳氮比(C/N)在0km处最高;2)有机碳含量在东向最高,全氮含量在东向和北向最高,全磷含量在北向最高;3)土壤有机碳含量与全氮含量、全磷含量、碳氮比、碳磷比、氮磷比,全氮含量与全磷含量、碳磷比、氮磷比,碳氮比与碳磷比,碳磷比与氮磷比呈极显著正相关(P0.01);碳氮比与氮磷比呈显著负相关(P0.05)。试验表明,土壤碳、氮、磷含量、碳磷比最高值出现在4.0km处,碳氮比最高值出现在0km处,而土壤中磷元素迁移速度较慢,因此推测露天开采煤炭形成的粉尘促进了无机碳的扩散和转换。 相似文献
2.
秸秆覆盖还田对黄瓜土壤碳氮比和微生物的影响 总被引：2，自引：0，他引：2
以"津春改良2号"黄瓜为试材,研究了秸秆覆盖及地膜覆盖处理对温室黄瓜结果期土壤有机碳、碳氮比和微生物的影响,以期探讨秸秆还田的效果和内在机制。结果表明:覆盖0.72kg·m-2秸秆量和地膜处理最为理想,可显著提高黄瓜结果初期和后期土壤有机碳含量和碳氮比,能显著提高黄瓜结果初期土壤5种微生物数量和后期细菌数;土壤中细菌数与0~20cm处有机碳含量、碳氮比呈显著正相关,土壤20~40cm碳氮比与纤维分解菌数呈显著负相关,而与固氮菌数呈显著正相关。 相似文献
3.
1 选择间作林地 选海拔 4 0 0～ 15 0 0m ,阴坡 ,中、下位 ,坡度 10～ 2 5° ,树龄 10年以上 ,胸径 10cm以上的中、成熟林 ,密度 5 0 0～ 6 0 0株 /hm2 ,郁闭度 0 7～0 9,森林小气候明显的板栗林地。土壤为黄棕壤至棕壤土 ,局部土层厚 4 0cm以上 ,土质以粗砂土或砂质壤土为好 ,pH值 5 5～ 6。种植穴距树干 1m外、土层厚处 ,穴规格 70cm× 70cm ,35cm深 ,种两层 (根据林地条件 ,穴可大可小 ,土层薄只种一层 )。2 选菌材 菌材选直径 5～ 10cm的板栗、茅栗、栓皮栎、麻栎等栎类新伐带皮木材 ,晾晒 15～ 2 0d(抑制生命力 )后截成长 5 0c… 相似文献
4.
白刺沙堆周围土壤理化性状的空间分布特征 总被引：2，自引：0，他引：2
为了探讨沙堆灌丛植被"肥岛"效应影响下土壤养分的空间分布特征,以宁夏东部荒漠灌丛白刺为研究对象,对沙堆不同生境,不同土层的pH、全盐和碳氮磷含量及其比值进行了研究。结果表明:白刺沙堆土壤pH和全盐均随土层的加深而升高,相对于pH,全盐的升高更为显著(P0.05),有机碳(SOC)、全氮(TN)和全磷(TP)随土壤深度的增加总体上呈逐渐降低的趋势,在土壤表层(0~40cm),3种生境下土壤养分含量为冠下冠缘灌丛间地,TP相对于SOC和TN在不同生境、不同土层间变化不显著(P0.05);在表层土壤(0~20cm)处,沙堆冠下土壤的碳氮比(C/N)、碳磷比(C/P)和氮磷比(N/P)呈极显著增加趋势;离植株不同距离的3种生境下,白刺沙堆土壤的C/N、C/P和N/P几乎无明显的规律性,经方差分析可知,土层对SOC和TN影响显著(P0.05),对TP无影响(P0.05),距离仅对SOC有显著影响,而距离与土层的交互作用对三者均有显著影响(P0.05)。白刺沙堆土壤pH和全盐对C/N、C/P、N/P的贡献为正,SOC、TN和TP对C/N的贡献均为负。 相似文献
5.
6.
青海野生果树资源 总被引：3，自引：0，他引：3
青海位于东经 89°3 5′～ 10 3°0 4′,北纬 3 1°3 9′～ 3 9°19′。日温差大 ,全年日照时数 2 3 14 .5～ 3 5 5 0小时 ,太阳辐射强 ,地形复杂 ,海拔多在 3 0 0 0 m以上 ,降水量少且分布不均匀 ,东湿西旱。东部为黄土栗钙土带 ,西部为荒漠土带 ,南部为高山土带。境内东北部为温带草原 ,西北部为温带荒漠 ,南部为高寒草原[1 ] 。1 野生果树分布区域青海野生果树主要分布于黄河、湟水河、大通河流域。依据地貌、气候、生态环境将其划分为四个区。1.1 西倾山区位于黄河以东以南的西倾山地区。野生果树种类丰富 ,有楸子、海棠、山楂、毛樱… 相似文献
7.
以内蒙古科尔沁地区盐碱土为研究对象,采集不同治理措施下的盐碱土0～20、20～30 cm和30～50 cm土样分析其土壤团聚体组成和碳氮含量的变化.试验处理分为2个梯度中度M和重度L,空白处理(MCK、LCK)、铺细沙处理(MS、LS)、有机质处理(MY、LY)、腐殖酸处理(MF、LF)和脱硫石膏处理(MT、LT),研究人为治理措施对盐碱土团聚体组分和碳氮的影响,以期揭示不同治理措施下土壤有机碳、全氮的固持机制,为合理的治理措施提供参考依据.结果 表明:中度盐碱对照和4种不同治理措施下土壤机械稳定性团聚体以＜0.25 mm和0.25～2.00 mm粒经为主,重度盐碱以＞5.00 mm为主;与中度盐碱对照相比,4种治理模式下不同土层＜0.25 mm粒经明显增加;与重度盐碱对照相比,0～20 cm土层＜0.25 mm粒经明显增加增加,＞5.00 mm粒经明显减少,其它土层粒经无明显差异;与对照相比,不同梯度(中度、重度)4种不同治理措施下土壤有机碳不同程度地增加,MF＞MY＞MS＞MT,并且随着土层的加深而降低,具有表矩形特征;与对照相比,不同梯度4种不同治理措施下土壤全氮不同程度地增加,中度盐碱0～20 cm土层MS＞MF＞MY＞MT,其它MF＞MS＞MY＞ MT,重度盐碱0～20 cm土层MF＞MS＞MY＞MT,20～30 cm土层MF＞MY＞MS＞MT,30～50 cm土层无显著差异MF比其它处理要低,并且随着土层的加深而降低.相对于对照盐碱化裸地,不同治理措施能够有效改善土壤团聚体特性,优化土壤主要理化性质,其中以添加腐殖酸为最佳治理措施. 相似文献
8.
中国沙红桃果实圆形 ,果个大 ,全红色 ,肉质细 ,香味浓 ,耐贮运 ,深受人们青睐。 1 997年山东省五莲县从河南省灵宝市园艺场引进该品种接穗 ,1 998～ 2 0 0 2年通过 5年的精细管理 ,获得较好的经济效益 ,现报道如下。1 试验园基本情况试验园设在五莲县洪凝镇集后村 ,地处日照市北部丘陵地区 ,海拔 1 0 0～ 70 0 m,年平均气温 1 3 .1℃ ,1月平均气温 -2 .4℃ ,7月平均气温 2 5.2℃ ,年平均降水量 83 5mm,年平均日照时数 2 50 8小时 ,年无霜期 1 98天。土壤为棕壤土 ,土层厚 1 5～ 2 5cm,p H值 6.8～ 7.0 ,0～ 40 cm土层含有机质 0 .88%、速… 相似文献
9.
以宁夏荒漠草原不同土地利用方式(耕地、弃耕地、草地和柠条地)的土壤为研究对象,测定了不同土层土壤有机碳和活性有机碳含量,分析了土壤活性有机碳占有机碳的比例,以期探寻不同土地利用方式对土壤活性有机碳的影响。结果表明:不同土地利用方式土壤总有机碳含量范围在1.78~6.17 g·kg^-1,具体表现为弃耕地>柠条地>草地>耕地。表层(0~5 cm)土壤有机碳含量显著高于深层(10~60 cm),说明荒漠草原土壤有机碳主要富集在表层;4种土地利用方式土壤易氧化有机碳含量为0.57~1.38 mg·g^-1,变化趋势具体表现为柠条地>草地>耕地>弃耕地,且柠条地在每个土层都高于其它3种土地利用方式;土壤可溶性有机碳含量范围为6.8~11.1 mg·kg^-1,变化趋势表现为草地>耕地>柠条地>弃耕地。土壤易氧化有机碳含量占有机碳的比例范围为13.7%~43.1%,大小排序为柠条地>耕地>草地>弃耕地;土壤可溶性有机碳含量占有机碳的比例范围为0.11%~0.48%,比例大小为耕地>草地>柠条地>弃耕地,耕地和草地中土壤可溶性有机碳含量占有机碳比例随着土壤深度的增加而减小,这与有机碳在耕地和草地中变化趋势一致。土地利用变化可以显著影响土壤活性有机碳的含量与分布,能够敏感的反映土壤碳库的变化,可以作为评价宁夏荒漠草原土壤质量和肥力的指标之一。 相似文献
10.
新选育的抗寒、耐旱短枝型苹果良种——海珠短富1号、2号 总被引：1，自引：0，他引：1
1 海珠短富 1号 系 1993年发现的长富 2号短枝型芽变 ,芽变母株地处我市海拔 12 2 5 m的干旱高寒山区 ,年均温不足 9℃ ,极端低温— 2 2℃左右 ,无霜期 140天 ,土质瘠薄 ,干旱少雨 ,无灌溉条件 ,冬春多强西北风 ,立地条件十分恶劣。1988年我市发生了前所未有的严重冻害 ,同园的苹果树除海珠短富 1号母株和少数几株国光外 ,其它品种如金冠、红星和富士无一幸免。该单株 1991年 4年生结果 5 .6kg,1994～ 2 0 0 0年 ,产量一直维持在35～ 4 5 kg之间 ,今年该母株已 14年树龄 ,其树高仅有2 75 cm,东西冠径 2 2 6cm,南北冠径 2 74 cm,树冠仅有同… 相似文献
11.
研究了塞罕坝地区云杉人工林土壤有机质、pH、全磷、全氮、全钾、速效磷、速效钾和碱解氮的含量在不同地势（沟底、坡面和曼甸）和不同土层深度条件下的差异。结果表明,0～10 cm深度土壤各类养分在坡面地势的含量显著高于沟底和曼甸,其中有机质、全磷、速效磷和碱解氮含量平均相差50.7%、34.8%、37.4%和46.3%,沟底的速效钾和碱解氮显著高于曼甸;10～20 cm深度土壤有机质含量、全磷含量、全钾含量、速效磷含量和碱解氮含量存在显著差异,以上元素在坡面地势的含量比沟底和曼甸平均高出46.7%、34.2%、22.7%、27.3%和63.8%,但沟底和曼甸中各类元素的差异不显著;20～40 cm深度土壤有机质、速效磷和碱解氮含量存在显著差异,坡面的含量明显高于沟底和曼甸,但沟底和曼甸中各类元素的差异不显著。相同地势条件下,各类土壤养分元素均呈现出地表高于地下的现象,其中0～10 cm深度土壤有机质、全氮、全钾和碱解氮含量分别比20～40 cm深度土壤高出65.2%、53.2%、80.3%和64.8%,pH在不同土壤深度间无明显差异。研究结果为塞罕坝云杉人工林经营提供了理论依据。 相似文献
12.
A general framework of ecosystem hotspots suggests variation in soil metabolic activity can be understood through the relative
distribution and intensity of patches of disproportionately high ecosystem process rates. To better understand the causes
of soil metabolic spatial variability and the variation in ecosystem hotspots we quantified soil respiration (R) spatial heterogeneity
across a network of seven sites spanning a 2,489 m elevation gradient in the Santa Rosa Mountains of Southern California.
At each site, soil samples were collected from 0–5 and 5–15 cm soil depths at 2 m intervals along three 100 m transects. Each
soil sample was analyzed for organic matter content (SOM) and was incubated at 40% water holding capacity for 20 days. R was
measured at days 5 and 20. Strong contrasts were observed between the relationships of soil physical variables and R at scales
of individual landscapes and the whole region. Notably, the relationship between SOM and R was positive within individual
landscapes and negative across the entire region. Plant canopy microenvironments were associated with elevated SOM and R relative
to the interspaces. This microenvironment effect on R was reduced by elevation, incubation interval, and soil depth. Geostatistical
analyses conducted individually for each site identified an increasing range of autocorrelation from 2 to 10 m and a decreasing
proportion of variation that was included in this range with elevation. These results suggest hotspots increase in size but
decrease in intensity with elevation thereby creating a maximum hotspot effect at middle elevations. 相似文献
13.
为了解不同土地利用方式对冀西北坝上地区土壤化学性质的影响,对该地区4种土地利用方式(围封林地、围封采伐地、未围封林地和耕地)下的土壤化学性质进行了分析.结果 表明:耕地的pH在7.5～8.5之间,明显高于其他3种土地利用方式(在6.5～7.5之间)(P＜0.05);耕地土壤的有机质、全氮、全磷、全钾及速效氮、磷、钾都明显高于3种林地(P＜0.05);2种封育林地表层土壤(0～10 cm)各养分含量明显高于未封育林地(P＜0.05),但深层土壤差异不明显.土地利用方式对土壤养分的垂直分布有显著影响,耕地土壤养分,除速效磷外,均表现为先下降后上升的趋势,养分含量变化曲线呈"V"型;3种林地土壤养分随土层深度的增加而降低,拐点均在10～20 cm土层,养分含量变化曲线呈"L"型.由以上结果得出结论,土地利用方式对土壤养分含量及其空间分布具有明显影响,耕地因为人工施肥的原因各养分含量明显高于林地,但土壤有明显的盐碱化趋势;封育可明显提高林地表层土壤养分含量,但对深层土壤影响较小. 相似文献
14.
Urban forests play a vital role in building soil organic carbon pools in urban areas. In many cases, urban forests are constructed on land previously used for agriculture, parks, or buildings. However, it is still being determined whether historical land use affects soil organic carbon (SOC) stocks in these forests. In this study, we asked: 1) How are SOC and its labile fractions (LOC) in urban forests affected by historical land use? and 2) How do SOC and LOC vary with time and vegetation type in urban forests built on land with different histories? We collected soil samples at three soil depths, 0–10, 10–20, and 20–30 cm, in 48 evergreen and 77 deciduous forest plots in 77 parks in Beijing, all built within the last 30 years. Plots represent two historical land use types, vegetated or non-vegetated, and three planting time classes, young (5–10 years), intermediate (11–20 years), and old (21–30 years). Our findings showed that there were significant differences between historical land use types in SOC and microbial organic carbon (MBC), this may be due to backfill soil before greening on non-vegetated land. Urban forests that were built on vegetated land accumulated SOC over time, while those on historically non-vegetated land did not. Evergreen forests had greater SOC and LOC than deciduous forests only on historically non-vegetated land. In addition, SOC and LOC were found to be negatively affected by increased soil bulk density. However, soil bulk density was not significantly different between both historical land use types and urban forest types. Overall, our study indicates that if SOC sequestration is a high priority in urban forests, cities could concentrate on more efficient management to increase SOC, such as soil rehabilitation and the use of evergreen tree species. 相似文献
15.
《International Journal of Fruit Science》2013,13(2):85-111
ABSTRACT Ericoid mycorrhizal fungi (EMF) form symbiotic relationships with roots of blueberry plants providing increased access to nutrients from fertilizers and soil. In August of 2001, we sampled 55 fields in Oregon to assess the mycorrhizal status of blueberry plants under production conditions and to determine whether any relationships exist between field characteristics, root distribution, soil characteristics and level of colonization by mycorrhizal fungi. Variation in measured soil characteristics, root type, root distribution and mycorrhizal colonization occurred with cultivar, field age, bed type, rate of nitrogen fertilization, irrigation type, and mulch. Root biomass was lower in the upper 15 cm of soil compared to 15-30 cm depth. Distribution of roots between the two sampled depths varied significantly with field age, nitrogen fertilization rate, and the time of 50% harvest for the different cultivars sampled. Root length was generally greatest in the upper 15 cm of the soil than at the 15-30 cm depth. Root colonization by ericoid mycorrhizal fungi (EMF) ranged from 0.5 to 44% of total root length with higher colonization generally occurring in the upper 15 cm of the soil where the majority of smaller, finer roots were found. Colonization generally increased with increasing plant age. In young plants the highest levels of colonization were found in roots from the upper 15 cm of soil while in older plants the highest levels of colonization were found in roots at the 15-30 cm depth. Colonization of roots by EMF in the upper 15 cm of the soil tended to decrease with increasing N fertilization rate, while root colonization at the 15-30 cm depth was unaffected by rate of N fertilization. Roots on cultivars that fruited early in the season tended to have higher levels of colonization than cultivars that fruited later in the growing season. Root biomass and root length were negatively correlated with soil pH and available Ca in soil, while root colonization by EMF was negatively correlated with ammonium levels in the soil. Differences in soil characteristics, root type and distribution, and mycorrhizal colonization found in this study need to be investigated in terms of production efficiency of blueberry in Oregon. 相似文献
16.
为了探究公路建设过程中外来植物的入侵格局及其与路域生态系统的关系,研究了滇中地区路旁云南松林内紫茎泽兰的入侵扩散格局及其对云南松林功能属性和土壤养分的影响。结果表明：(1)紫茎泽兰主要分布于距公路5～20 m的范围内,不同公路距离对紫茎泽兰丛数、丛面积、株高、盖度均具有显著影响;(2)随着紫茎泽兰入侵程度的增加,云南松综合性状值呈现先增加后降低的趋势,而林下植物多样性和功能丰富度(FRic)下降趋势显著;紫茎泽兰入侵对云南松林下土壤有机碳及全氮的影响均呈现先增加后降低趋势,在紫茎泽兰盖度为40%左右,有机碳和全氮含量最高;(3)路径分析结果表明林下群落功能属性对土壤有机碳的综合作用系数最高,达-0.527;紫茎泽兰入侵盖度及林冠植物云南松性状值对土壤全氮的总体作用系数较高,分别为-0.698和0.759;紫茎泽兰对土壤全磷的总体作用系数最高,达0.681。以上结果表明道路建设导致的紫茎泽兰的扩散程度可以通过多种途径共同影响土壤生态系统过程及功能,因此,在滇中地区道路建设过程中,有效防控紫茎泽兰入侵及提升云南松林下群落组成与结构对路域生态系统健康具有重要作用。 相似文献
17.
Spatial dependence and the relationship of soil organic carbon and soil moisture in the Luquillo Experimental Forest,Puerto Rico 总被引：11，自引：0，他引：11
Wang Hongqing Hall Charles A.S. Cornell Joseph D. Hall Myrna H.P. 《Landscape Ecology》2002,17(8):671-684
We used geo-spatial statistical techniques to examine the spatial variation and relationship of soil organic carbon (SOC) and soil moisture (SM) in the Luquillo Experimental Forest (LEF), Puerto Rico, in order to test the hypothesis that mountainous terrain introduces spatial autocorrelation and crosscorrelation in ecosystem and soil properties. Soil samples (n = 100) were collected from the LEF in the summer of 1998 and analyzed for SOC, SM, and bulk density (BD). A global positioning system was used to georeference the location of each sampling site. At each site, elevation, slope and aspect were recorded. We calculated the isotropic and anisotropic semivariograms of soil and topographic properties, as well as the cross-variograms between SOC and SM, and between SOC and elevation. Then we used four models (random, linear, spherical and wave/hole) to test the semi-variances of SOC, SM, BD, elevation, slope and aspect for spatial dependence. Our results indicate that all the studied properties except slope angle exhibit spatial dependence within the scale of sampling (200 – 1000 m sampling interval). The spatially structured variance (the variance due to the location of sampling sites) accounted for a large proportion of the sample variance for elevation (99%), BD (90%), SOC (68%), aspect (56%) and SM (44%). The ranges of spatial dependence (the distances within which parameters are spatially dependent) for aspect, SOC, elevation, SM, and BD were 9810 m, 3070 m, 1120 m, 930 m and 430 m, respectively. Cross correlograms indicate that SOC varies closely with elevation and SM depending on the distances between samples. The correlation can shift from positive to negative as the separation distance increases. Larger ranges of spatial dependence of SOC, aspect and elevation indicate that the distribution of SOC in the LEF is determined by a combination of biotic (e.g., litterfall) and abiotic factors (e.g., microclimate and topographic features) related to elevation and aspect. This demonstrates the importance of both elevation and topographic gradients in controlling climate, vegetation distribution and soil properties as well as the associated biogeochemical processes in the LEF.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
18.
Invasion of grasslands by woody plants has been identified as a key indicator of changes in ecosystem structure and function in arid and semi-arid rangelands throughout the world. We investigated changes in the balance between woody and herbaceous components of a semi-arid landscape in western Colorado (USA) using historical aerial photography. Aerial photographs from 1937, 1965–67, and 1994 were sampled at matched locations within overlapping photographs. We modeled change in spatial pattern and heterogeneity across the entire landscape and found a small, net decrease in woody canopy cover; however means disguised normal distributions of change that demonstrated offsetting increases and decreases. We described a region of widespread canopy decline within piñon-juniper forests between 2300 and 2600 m (7500–8500 feet) and a region of predominant increase at lower elevations, between 1800 and 2250 m (5900–7400 feet). It remains unclear whether this shift was driven by climate or by human-caused or natural disturbance. Mean conifer cover decreased within coniferous forests, which counteracted a trend of increased conifer cover in mixed forests, savanna-like woodlands, and the shrub steppe. Disturbance had a significant interaction with cover change in several communities, including forests, savanna and shrublands. Anthropogenic disturbances counteracted successional trends toward canopy closure more than wildfires, but this did not entirely explain observed canopy decline. The natural dynamics in this region also caused diverse changes rather than a simple progression towards increased forest cover. Importantly, temporal change in vegetation varied spatially across the landscape illustrating the importance of landscape level, spatially explicit analyses in characterizing temporal dynamics. 相似文献
19.
长期施用氮磷钾肥对黄土高原地区苹果产量及土壤养分累积与分布的影响 总被引：4，自引：0，他引：4
对连续8 a施用氮磷钾肥的黄土高原地区‘红富士’苹果园的产量及土壤养分变化进行了研究,以探明长期施用氮磷钾化肥对苹果产量与土壤养分累积与分布的影响。结果表明,施用氮磷钾化肥(NPK处理)显著增加了苹果产量,增产率为12.8%～128.3%,增产率随施肥年限增加有增加趋势。NPK处理增加了果园土壤的有效氮、磷、钾含量,其累积量在不同土层中的分布差异较大。与对照(CK)相比较,NPK处理使0～20 cm、20～40 cm和40～60 cm土层中的速效氮含量平均分别增加了24.9 mg·L-1、36.9 mg·L-1和49.7 mg·L-1,速效磷增加了20.1 mg·L-1,12.6 mg·L-1和4.3 mg·L-1,速效钾增加了50.9 mg·L-1、61.8 mg·L-1和31.2 mg·L-1。这表明长期施肥下,果园土壤中速效氮的累积量随着土层深度增加,速效磷的累积量随土层深度减少,速效钾累积主要分布在0～40 cm土层。相关性分析表明,20～40cm土层的速效氮和速效磷含量与当年的苹果产量呈显著正相关关系,土壤速效养分含量与上一年度苹果产量的相关性较差。 相似文献