首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 265 毫秒
1.
在晋西黄土区,研究了荒草地、锦鸡儿灌木林地和刺槐乔木林地3种典型植被不同土层的土壤密度、含水量、贮水能力和入渗性能的差异及其相关性,结果显示:3种植被类型都能有效减小表层(0 20 cm)土壤密度;3种植被类型表层(0 20 cm)的土壤滞留贮水量较大,锦鸡儿林地(198.80 t·m-3)刺槐林地(166.10 t·m-3)荒草地(87.37 t·m-3),20 40 cm土层的土壤滞留贮水量也是锦鸡儿林地(127.30 t·m-3)刺槐林地(55.60 t·m-3)荒草地(47.30 t·m-3),表明在3种植被类型中,锦鸡儿林地对晋西黄土丘陵区土壤水分的涵养作用最强;锦鸡儿林地的土壤稳渗速率最大,为1.80 mm·min-1,刺槐林地次之,为1.46 mm·min-1,荒草地依然最小,且锦鸡儿林地土壤的均渗速率最大,为4.81 mm·min-1,其次是刺槐林地,为4.51 mm·min-1,荒草地最小。土壤密度与滞留贮水量呈极显著负相关关系,与土壤初渗速率和均渗速率呈极显著负相关关系,与稳渗速率呈显著负相关关系,非毛管孔隙度与稳渗速率和均渗速率存在极显著相关关系。Kostiakov模型和Horton模型对晋西黄土区3种植被类型土壤入渗过程模拟的拟合系数高达0.97和0.95,明显优于Philip模型(0.43)。  相似文献   

2.
土壤水分对杜仲剥皮再生的影响   总被引:2,自引:1,他引:2  
分别对12和25年生杜仲进行Ⅰ、Ⅱ、Ⅲ、Ⅳ级供水处理,研究不同水分条件对杜仲愈伤组织和再生皮生长的影响.结果表明:供水改善了林地水分条件,土壤平均含水量和贮水量增大,25年生杜仲消耗土壤水分较多,土壤含水量较12年生杜仲林地的低.杜仲剥皮后,供水能加快愈伤组织的形成,剥皮后第5 d,处理Ⅰ、Ⅱ、Ⅲ均有微绿色的愈伤组织出现,较对照提前5 d左右;剥皮后25 d,12和25年生的愈伤组织厚度分别达到1.00和0.94mm,生长速度分别为0.040和0.037 mm·d-1,分别较对照增加47.1%和80.8%.供水能显著促进杜仲再生皮的生长,剥皮后5个月,12和25年生杜仲Ⅰ、Ⅱ、Ⅲ、Ⅳ级供水处理的再生皮厚度分别较对照增加5.0%、22.5%、75.8%、71.7%和18.5%、29.3%、80.7%、95.0%.6月份是杜仲再生皮生长的关键期,供水对再生皮生长最有利.杜仲水分利用效率在Ⅲ级供水处理时最大,12和25年生分别较对照提高39.3%和37.4%.生长季中,土壤含水量应保持在160~170 g·kg-1.  相似文献   

3.
江西安福不同类型毛竹林土壤入渗与贮水特征   总被引:2,自引:0,他引:2  
对江西安福毛竹林类型(毛竹纯林、竹阔混交林和竹杉混交林)土壤入渗与贮水特征进行研究,以中亚热带常绿阔叶林和杉木纯林为对照。结果表明,毛竹纯林0~60 cm土壤初渗率、平均渗率、稳渗率和前60 min渗透总量分别为1.64 mm/min,1.31 mm/min,1.23 mm/min和157.10 mm,均小于毛竹混交林。不同类型毛竹林土壤渗透性能均随着土层深度的增加而降低。用Kostiakov模型进行不同类型毛竹林不同土层深度的土壤入渗过程拟合,其决定系数为0.602 1~0.949 6,均达到显著水平。不同类型毛竹林土壤贮水能力差异显著,0~60 cm土壤滞留贮水量在27.47~45.40 mm,毛竹混交林大于纯林。不同类型毛竹林土壤贮水能力均表现为随着土层深度的增加而减弱。毛竹纯林的土壤入渗和贮水性能劣于阔叶林和杉木林,而混交经营有利于改善毛竹林土壤结构,从而提高毛竹林水源涵养功能。  相似文献   

4.
章古台沙地樟子松人工林土壤水分动态研究   总被引:11,自引:1,他引:11  
对章古台地区沙地樟子松人工林和流动沙地土壤水分动态进行了定位研究,结果表明,在整个生长季节内,降雨、蒸散、地形及土壤质地等因素对沙地土壤水分变化影响显著。0-100cm土层土壤贮水量以沙丘下部林地为最高,流动沙地次之,丘顶林地最低。表层0-5cm土壤含水量受降雨影响变幅较大,林地高于流动沙地;樟子松主要根栖层25-50cm土壤含水量低于流动沙地。5、6、9月为失墒期,7—8月为蓄墒期,其中以6月份土壤贮水量为最低。  相似文献   

5.
湘西北小流域典型植被恢复群落土壤贮水量与入渗特性   总被引:3,自引:0,他引:3  
对湘西北女儿寨小流域7种典型植被恢复群落土壤贮水量与入渗特征进行研究.结果表明:1) 森林群落土壤饱和贮水量与最大吸持贮水量均高于荒草灌丛群落,表明森林植被能较好地改良土壤、提高土壤持水能力;2) 通用经验方程对各种植被类型土壤入渗过程的拟合效果最好,Kostiakov方程次之,Horton方程最差;3) 毛竹杉木混交林群落土壤初渗率(17.10 mm·min-1)和平均入渗率(7.42 mm·min-1)最大,杉木人工林稳渗率(11.51mm·min-1)最高,油桐人工林初渗率(4.93 mm·min-1)、稳渗率(0.52 mm·min-1)和平均入渗率(1.23 mm·min-1)均最小;4) 坡位对土壤入渗率的影响具有不确定性,杜仲人工林表现为上坡>中坡>下坡,马尾松天然林、润楠次生林及荒草灌丛群落表现出与之相反的规律,以下坡最高,上坡最低,杉木人工林和毛竹杉木混交林则以上坡最高,中坡最低,油桐人工林以中坡最高,上坡最低;5) 主成分分析结果表明,土壤水分入渗性能与土壤持水量、土壤孔隙状况密切相关,并受林分结构、植物群落生物量、海拔、坡度及坡位因子的制约,而坡向、草层盖度、土壤密度的作用较小;6) 通过双重筛选逐步回归分析,建立土壤初渗率、稳渗率、平均入渗率的主导因子方程.  相似文献   

6.
内蒙古大青山典型植被水源涵养功能分析   总被引:2,自引:2,他引:0  
通过对内蒙古大青山3种典型植被及其土壤的测定,研究比较了不同森林植被的水源涵养功能。结果表明:油松林的林冠截留量最大,为0.170mm,落叶松林和白桦林依次为0.104mm和0.052mm;落叶松林枯落物持水能力显著高于白桦林和油松林,白桦林土壤贮水能力大于落叶松林和油松林;经综合评价,落叶松林水源涵养能力最强,油松林其次,白桦林水源涵养能力最差。  相似文献   

7.
河口县立地条件对柚木生长影响的调查研究   总被引:1,自引:0,他引:1  
选择河口县马场等3个造林地块,从海拔100-800m共设置标准地20块、样方20块,调查不同立地条件对柚木生长的影响。结果为海拔400m以下为柚木最适宜区,400-600m为适宜区,600-800m为次适宜区;坡脚好于坡腹,坡腹好于坡顶;背风山坳、坡麓、沟谷、平地优于迎风坡及坡顶;土壤厚度大于80cm则柚木生长良好,低于50cm则生长不良;以马鹿草为主的植被群落有利于柚木生长,而以白茅为主的植被群落对柚木生长极为不利。  相似文献   

8.
为探究保梅岭保护区内不同类型林分林下土壤水文特性,以该区域内5种典型人工纯林及天然次生林为研究对象,分土层深度测定及计算各林分土壤容重、孔隙度、贮水量等物理—水分指标。结果表明:(1)各类型林分土壤容重、贮水量、含水量、涵蓄降水量和有效涵蓄量均随着土壤深度的增加而增大,孔隙度随土层深度加深的变化规律在各林分间表现不同。(2)6种林分土壤容重大小介于1.16g/cm3~1.52g/cm3,以加勒比松林最大,天然次生林最小。(3)总毛管孔隙大小介于28.61%~52.54%,滞留贮水量大小介于48.24mm~147.96mm,以天然次生林最大,加勒比松林最小。(4)有效涵蓄量大小介于40.87mm~129.18mm,以天然次生林最大,桉树林最小。综合分析表明,天然次生林土壤通气透水性、贮蓄和调节水分能力优于人工纯林,而人工纯林中以枫香林涵养水源能力最佳。  相似文献   

9.
对芒果园及其灌草植被荒坡的土壤水文物理性质进行了对比测定。结果表明:1-40cm深度的土壤及容重,芒果园为1.34-1.45g/cm^3,相应比灌草植被荒坡(1.46-1.50g/cm^3)低0.05-0.12g/cm^3;而在40-100cm深度。两者的土壤容重则基本等值(1.62g/cm^3)。0-100cm深度的土壤总孔隙度、通气度、最大持水量和渗透速度的平均值,芒果园依次为50.15%、23.20%、34.28和1.77mm/min,分别比灌草植被荒坡高3.47%、5.22%、2.15%和0.75mm/min。说明灌草植被荒坡变为芒果园后对改良土壤结构、提高土壤持水量和增加土壤水分渗透速度都具有较显著的生态功能。  相似文献   

10.
在板桥河小流域选择植被一土壤具有代表性的样地,对植被结构、生物量和枯落物层、土壤的物理、化学、微生物学性质进行了研究。结果表明:(1)该流域的各种植被类型中,以灌丛草坡的面积最大(占39.5%),现有森林多为幼林,结构较差;(2)各种植被下土壤的有机质、全N、速效K含量都较丰富,但有效P含量较低;不同植被类型的土壤养分状况具有明显的差别,其中以竹林土壤的养分元素含量最高,灌丛草坡的最低;(3)森林植被的土壤物理性质明显优于灌丛草坡和灌木林;不同植被类型下的枯落物层最大持水量在5.89~29.45t/ha,以竹林的枯落物层贮水量最大;(4)土壤酶活性和C/N值表明,竹林土壤中有机质分解状况最好,而灌丛草坡的最差;(5)不同植被生物生长量大小为:竹林>针阔混交林>阔叶林>灌木林>针叶林>灌丛草坡,结合土壤理化、微生物性状来看,该流域的森林植被的土壤均具有较高的肥力水平,而灌丛草坡的土壤肥力状况相对较差。  相似文献   

11.
黄土区人工林的土壤持水力与有效水状况   总被引:33,自引:0,他引:33  
以晋西北黄土区河北杨林,小叶杨林和柠条灌木林为对象,就各人工林地的土壤持水力和在4个不同降水的土壤有效水动态特点进行了研究。结果表明,林地间土壤持水力和比水容量为:河北杨林〉小叶杨林〉柠条灌木林。各林地的土壤持水力和供水力普遍偏低。  相似文献   

12.
晋西黄土区主要造林树种单株耗水量研究   总被引:1,自引:0,他引:1  
依据水量平衡原理,采用桶栽试验分别测算晋西黄土区主要造林树种侧柏、刺槐、杏和河北梨生长季(4-10月)单株耗水量,并根据林地土壤水分动态及土壤水分特征曲线标定的各树种无效水界值,分析各树种土壤水分供耗特点及其有效性.结果表明:1)2002年(贫水年)生长季降水量430.7 mm,试验树种同期耗水量约为430~490 mm,供耗失衡;2003年(丰水年)降水量870.2 mm,耗水量约为480~515 mm,但降雨分配不均,5、10月供耗也略有失衡.2)不同树种年内土壤含水量变化趋势相近,而同月耗水量差异较大,同一树种不同月耗水量差异也较大,丰水年各试验地土壤水分状况要好于贫水年.3)侧柏、刺槐、杏和河北梨无效水界值分别为8.0%、8.4%、9.2%和9.7%,侧柏较其他3个树种利用水分能力强;贫水年林外单株树木土壤含水量在一段时间内低于对应树种的无效水界值,影响树木正常生长;单株树木依靠冬季和次年春季降水补充,生长季初期都能恢复到速效水水平.  相似文献   

13.
攀枝花干热河谷四种人工植被类型土壤水源涵养特征分析   总被引:6,自引:2,他引:6  
本文从土壤非毛管孔隙、入渗、最大可蓄水量和有效水贮量等方面评价了攀枝花干热河谷4种人工植被土壤的水源涵养功能。4个类型土壤蓄水能力均较低,70 cm土层最大可蓄水量变动范围在225 mm~285.5mm,有效水贮量在110 mm~169 mm之间。其中以香樟混交林水源涵养功能最强,其次分别是桉树林,新银合欢林,最差为番麻地。以变质花岗岩石发育的土壤母质层仍有较强的蓄水能力,最大可蓄水量(体积)含量达30%左右,有效蓄水量达20%。但土壤的入渗状况极差,稳渗率(K10)仅为0.2 mm.min-1。改善母质层的入渗状况是增加土壤旱季水分贮量的关键措施。人工造林可加速土壤层的形成进程,提高土壤的入渗率,如香樟-羊蹄甲基混交林,土壤层稳渗率为4.72 mm.min-1,而母质层仅为0.16 mm.min-1。  相似文献   

14.
Water is the key factor in vegetation growth in a loess area. Researchers have been keen on the study of tree transpiration for a long time. To provide a scientific basis and practical instruction for vegetation reconstruction and recovery in a loess area, the paper measured and calculated the water consumption of potted Platycladus orientalis, Robinia pseudoacacia, Armeniaca vulgaris and Pyrus hopeiensis separately during the growing season (from Apr. to Nov.). The four were the main afforestation species in a loess area of western Shanxi based on the principle of water balance. Using data on soil water dynamics and the range of available moisture on potted mature trees, the relationship between water supply and consumption and soil moisture availability and deficit state were analyzed. Several conclusions are listed as follows: 1) In the dry year (2002), during the growing season the precipitation was 430.7 mm and the water consumption of potted trees was from 430 to 490 mm. More water consumption and less available water supply occurred, showing a serious water deficiency. In the rainfall-rich year (2003), during the growing season the precipitation was 870.2 mm and the water consumption of potted trees was from 480 to 515 mm. Due to the uneven distribution of rainfall, the water budget balance was slightly affected in May and November. 2) The curves of soil water content of different species had similar annual changes, although the trends were different in the same month, and those of the same tree species in different test plots also had different trends in the same month. 3) Non-available soil water content of Platycladus orientalis, Robinia pseudoacacia, Armeniaca vulgaris and Pyrus hopeiensis was less than 8.0%, 8.4%, 9.2% and 9.7% respectively, which indicated that Pyrus orentalis used water more efficiently than the others. In the dry year (2002), for several months, soil water content of potted trees was lower than its threshold value for non-available soil water content, which could influence the healthy growth of trees. After supplements of precipitation of winter in the year and spring in the next year, soil water content was higher than the lower limit of soil readily available moisture content, which implied that a balance between inter-annual water supply and consumption could be maintained. __________ Translated from Scientia Silvae Sinicae, 2006, 42(9): 18–23 [译自: 林业科学]  相似文献   

15.
佛山市风水林林地表层土壤持水特性研究   总被引:1,自引:0,他引:1  
文章对广东省佛山市主要风水林群落表层土壤(0~20 cm)的持水特性进行了调查研究,结果表明:云端村、碧云村、寺边村、院头村风水林群落土壤持水能力较好,石潭刘村、塾坑村、荔枝塘村、山布村、宫花塘村、伦涌村、谭南村、杨坳村、新誉洞村风水林群落土壤持水能力中等,平南村、坑美村、万石头村的则较差。16个风水林群落枯落物最大持水率和最大持水量均低于南亚热带山地季风常绿阔叶林和全国平均水平。其表层土壤总孔隙蓄水量平均为97.26 mm,非毛管孔隙蓄水量平均为19.18 mm。土壤持水性各项指标之间显示出不同的相关性,土壤持水性与<0.01 mm土粒含量百分率、有机质含量和通气孔隙度呈极显著正相关。  相似文献   

16.
We conducted a trenching experiment in a mountain forest in order to assess the contribution of the autotrophic respiration to total soil respiration and evaluate trenching as a technique to achieve it. We hypothesised that the trenching experiment would alter both microbial biomass and microbial community structure and that fine roots (less than 2 mm diameter) would be decomposed within one growing season. Soil CO2 efflux was measured roughly biweekly over two growing seasons. Root presence and morphology parameters, as well as the soil microbial community were measured prior to trenching, 5 and 15 months after trenching. The trenched plots emitted about 20 and 30% less CO2 than the control plots in the first and second growing season, respectively. Roots died in trenched plots, but root decay was slow. After 5 and 15 months, fine root biomass was decreased by 9% (not statistically different) and 30%, (statistically different) respectively. When we corrected for the additional trenched-plot CO2 efflux due to fine root decomposition, the autotrophic soil respiration rose to ~26% of the total soil respiration for the first growing season, and to ~44% for the second growing season. Soil microbial biomass and community structure was not altered by the end of the second growing season. We conclude that trenching can give accurate estimates of the autotrophic and heterotrophic components of soil respiration, if methodological side effects are accounted for, only.  相似文献   

17.
Soil water and temperature measurements were made at a clearcutting in Jädraås, central Sweden, to give appropriate information for nutrient flow calculations and soil biological research. Compared to uncovered plots, slash‐covered plots were 1–2°C colder and had 3–6 volume percent higher water content in the 5 cm thick humus‐layer during the growing season following cutting. Relative to air, soil temperatures became warmer at both treatments during the second season and differences between uncovered and covered plots decreased. Tension dynamics in the mineral soil was most pronounced in uncovered plots, especially during the first dry growing season. The physically based model, SOIL, was used to analyse these observations and to estimate the effects of clearcutting. Simulated snow and frost depths, soil temperatures, water contents and tensions as well as ground water table were compared with measured data during a period of one to four years. Physical parameter values were estimated from independent measurements and by subjective optimization. Simulated soil water dynamics revealed the importance of hysteresis and vapour flows in sandy forest soils. The hydrological clearcutting effect as estimated from mature Scots pine evapotranspiration properties showed a 50% reduction of evapotranspiration, an increased soil water storage (0–1 m) of up to 120 mm and an increased percolation of 125 mm per year.  相似文献   

18.
Reeves I  Emery RJ 《Tree physiology》2007,27(11):1635-1645
Seasonal patterns of cytokinins (CKs) and microclimate were examined in the upper, middle and lower canopy layers of mature Acer saccharum Marsh. (sugar maple) trees to elucidate the potential role of CKs in the mediation of gas exchange. The upper canopy showed a distinctly dissimilar microclimate from the middle and lower canopy layers with higher photosynthetically active radiation and wind speed, but showed no corresponding differences in transpiration (E) or stomatal conductance (g(s)). Although E and g(s) tended to be higher in the upper canopy than in the middle and lower canopies, the differences were not significant, indicating regulation beyond the passive response to changes in microclimate. The upper canopy accumulated significantly higher concentrations of CKs, predominantly as ribosides, and all canopy layers showed distinct seasonal patterns in CK profiles. Multiple regression models showed significant relationships between both g(s) and E and foliar CK concentration, although these relationships varied among canopy layers. The relationships were strongest in the middle and lower canopy layers where there was less fluctuation in leaf water status and less variability in abiotic variables. The relationships between gas exchange parameters and leaf CK concentration began to decouple near the end of the growing season as foliar phytohormone concentrations changed with the approach of dormancy.  相似文献   

19.
经过连续3 a利用DBOL保水剂对黄连木裸根苗造林及幼林生长的试验研究,结果表明:(1)黄连木裸根苗造林保存率提高10.5%~14.5%;(2)黄连木幼林高生长量增加41.3 cm~53.0 cm,地径生长量增加1.83 mm~2.05 mm;(3)黄连木幼树提早15 d左右萌动,延迟10 d左右停止生长。  相似文献   

20.
在岷江上游干旱河谷岷江柏木幼林地经过连续4 a利用雨季种植绿肥压青,增加土壤肥力,提高水分利用率,促进幼树生长研究。结果表明:(1)种植红豆草的土壤0~40 cm含水量旱季增加3.68 g·kg-1,0~20 cm土壤容重降低0.07 g·cm-3;种植草木樨土壤0~40 cm含水量旱季增加4.18 g·kg-1,0~20 cm土壤容重降低0.05 g·cm-3;种植沙打旺土壤0~40 cm含水量增加2.46 g.kg-1,0~20 cm土壤容重降低0.18 g·cm-3。(2)种植绿肥压青,土壤有机质增加0.37 g·kg-1~0.55 g·kg-1,土壤CaCO3含量下降0.66 g·kg-1~1.36 g·kg-1,有效氮增加4.5 mg·kg-1~18.5 mg·kg-1,有效磷含量增加1.0~3.46 mg·kg-1,CEC比对照增加0.54~0.58mg.100g-1。(3)种植红豆草、草木樨、沙打旺绿肥压青对岷江柏木树高、地径生长有显著的促进作用,尤其种植红豆草的岷江柏木幼树生长最好,高、径生长为对照的1.7倍和1.6倍。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号