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油松、华北落叶松抗旱特性的研究 总被引:2,自引:1,他引:1
进行了油松,华北落叶松苗木盆栽试验,在土壤由湿(适宜)到严重干旱的变化过程中,测定了苗木的凋萎系数,叶片水势,根系活力,蒸腾强度,观察了苗木生长的外观反应。对两树种的抗旱性能进行了综合评价,结论是:油松的抗旱性能优于华北落叶松。 相似文献
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木兰科6个树种抗旱性及其抗氧化指标的测定 总被引:1,自引:0,他引:1
将木兰科6个树种进行28 d春旱处理,以观察田间生长状况,并测定土壤含水量及树种凋萎系数;干旱处理21 d时,测定植株叶片的抗氧化指标。结果表明:阔瓣含笑、乐昌含笑暂时凋萎系数均为7.6%,永久凋萎系数均为3.78%;金叶含笑、观光木、红花木莲、桂南木莲暂时凋萎系数均为14.2%,永久凋萎系数均为7.6%。根据以上结果及田间观察,6个供试树种抗旱能力由大到小排序为:阔瓣含笑、乐昌含笑、金叶含笑、观光木、桂南木莲、红花木莲。抗氧化指标测定结果显示:水分胁迫21d时,观光木和红花木莲总抗氧化能力有所降低,其余4个树种均升高;而抗坏血酸(Vc)和还原型谷胱甘肽(GSH)含量在6个树种中均升高。其中,阔瓣含笑和乐昌含笑升高幅度最大。 相似文献
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通过盆栽试验,测定评价了55个树种的稳定凋萎含水量及其耐干旱能力.①55个树种的初始凋萎含水量和稳定凋萎含水量分别变化在4.81%~11.05%和1.85%~5.87%,稳定凋萎含水量出现时间平均为24.99 d,变化在7.00 d~42.30 d,初始凋萎含水量与稳定凋萎含水量出现的时间平均相差11.11 d,变化在3.20 d~30.60 d;②初始凋萎含水量、稳定凋萎含水量出现的时间、初始凋萎含水量至稳定凋萎含水量出现的时间差随光照强度的减少而增加,而稳定凋萎含水量的变化不明显;③单因素评价与多因素综合评价结果有趋同性,但在树种的排序上存在差异.单因素评价和多因素综合评价结果可分别用于不同干旱类型环境,有些耐旱力较强的树种同时也有较强的耐涝性,有的则相反. 相似文献
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采用盆栽称重法,通过对在干旱期间的土壤含水量分析了华北落叶松土壤水分含量的变化动态以及凋萎系数。结果显示,1 a中6月上旬土壤含水量最低,4月份和8月份为土壤含水量高峰期。华北落叶松的凋萎系数为4.83%,苗木从控水至暂时凋萎时间可以维持35 d. 相似文献
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生物质能源树种光皮树苗木生长规律及育苗技术研究 总被引:1,自引:0,他引:1
通过对赣南乡土生物质能源树种、食用油料树种光皮树的种子预处理、种子主要参数测定、以及对苗木物候、苗木根系生长、苗木生长节律进行研究,从而得出光皮树实用的、较为系统的育苗技术。 相似文献
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1984~1988年,在江西省分宜县山下林场的亚热带人工杉木林和马尾松林中,对土壤的水分—物理性质及其水分含量的变化进行了测定,结果表明:本试验区土壤为重壤土,其水分—物理性质较差,有林地土壤含水量较无林地高,且变幅较小。土壤含水率与当地的主要气象要素(气温、空气湿度、降雨量、蒸发量)呈多元回归相关。据回归分析,杉木林土壤水分含量受气候变化影响的土层深度较浅,达0~20cm,而皆伐迹地受气候影响的土层较深,达0~40cm。 相似文献
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Soil disturbance by heavy machinery usually causes a decrease in porosity and an increase in soil strength, which may limit access to nutrients and compromise seedling survival and growth. This study used a soil strength and a greenhouse experiment to assess the impact of compaction on lodgepole pine (Pinus contorta Dougl. Ex. Loud. var. latifolia Engelm.) seedling growth and the degree to which soil water influences the effects of compaction. A silt loam soil was collected from a forest landing in the central interior of British Columbia (BC) in the Sub-Boreal Spruce Biogeoclimatic zone. The silt loam soil was used in a soil strength experiment where soil with four water content levels (0.10, 0.18, 0.27, and 0.36 cm3 cm−3) was packed into 0.21 cm3 cores with three levels of compaction (74, 79, and 84% of maximum bulk density (MBD)). Soil strength was strongly affected by compaction and water content. In the greenhouse experiment, three water content levels (0.10–0.15, 0.20–0.30, and 0.30–0.35 cm3 cm−3) and three levels of compaction (67, 72, and 76% of MBD) were applied to soil in pots and 1-year old lodgepole pine seedlings were grown in the pots. Soil strength was highest (1275 kPa) for the high compaction and dry water content treatment in the greenhouse experiment. Though the soil strength for this treatment did not exceed 2500 kPa, the effect of compaction on growth was noticeable, with a decrease in diameter growth, total shoot mass, and new root mass as compaction increased at the dry water content. At dry water content and high compaction, foliar nutrient concentrations were greatest. Generally, water content had a greater impact on seedling growth than did compaction, at the levels of compaction used in this study. This study indicates that if there is a critical value for mechanical impedance of the conifer roots, it likely occurs below 2500 kPa. Our results are consistent with the explanation that soil strength incrementally affects root growth below 2500 kPa for this soil type. Expensive rehabilitation techniques may not be needed on lightly disturbed soils similar to that used in this study if soil water content is high enough throughout the conifer growing season to alleviate the effects of compaction on soil strength. 相似文献
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本项研究主要在山东省冠县毛白杨林场进行,研究了毛白杨片林的林分生长规律、生物量积累及它们与土壤条件的关系。研究结果表明毛白杨生长量在不同土壤上差异甚大,其年平均材积生长量,壤质褐潮土>夹淤沙壤质潮土>通体沙质潮土>粘质褐潮土>风沙土;毛白杨片林数量成熟龄在壤质褐潮土为13a以后,其它几种肥力差的土壤为7-9 a;壤质褐潮土上毛白杨林速生期持续12 a以上,其它几种土壤为4-9 a。据观测毛白杨片林粗生长高峰期显著,5月份粗生长占全年总量40-60%。高生长高峰期持续期较长,为6-7月。毛白杨片林生物量积累随林龄增大而增加,尤其2-10 a增长速度最大,10-14 a以后生物量积累也有所增加,但增加速度减缓。 相似文献
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用定位研究的方法,在丹东不同区域建立生态因子观测场,测定不同土层厚度、pH值、土壤养分含量、空气温湿度、光照强度、降雨、蒸发量等各因子对银杏生长的影响,结果表明:在不同的温度条件下,银杏种子萌发和幼苗生长状况不同,经20 d后,种子发芽率恒温比变温高6.2个百分点,幼苗根系生长、苗高、地径恒温比变温分别提高36.7%和16%。经过遮阴处理,银杏幼苗生长好于对照区。生长在壤土和沙壤土上的银杏其生长表现优于生长在沙土和黏土上的,土壤含盐量以0.03%~0.043%,银杏生长良好。银杏对pH值适应范围很宽,在pH值4~8.5的土壤上均能生长。 相似文献
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浙江省世行贷款造林项目环境监测研究报告 总被引:2,自引:0,他引:2
在坡度较陡的轻壤质山地红壤上,用全垦整地营造杉木林,地表径流系数在4.2%以下,土壤侵蚀模数仅第1年有少量发生;施用磷酸铵后,土壤中的有效磷头3年均比对照区高,林木高生长比对照区增60%。 相似文献