机构地区:[1]中国林业科学研究院森林生态环境与保护研究所,北京100091 [2]北京林业大学生物科学与技术学院,北京100083 [3]国家林业局保护司,北京100043
出 处:《林业科学研究》2005年第3期315-320,共6页Forest Research
基 金:国家林业局动植物保护司专项(2002)"珍稀濒危植物肉苁蓉和寄主植物梭梭资源开发其对环境的影响"课题和国家林业局森林生态重点实验室资助项目的一部分
摘 要:在新疆吉木萨尔县林木良种试验站的肉苁蓉良种繁育基地内,选择立地条件、梭梭树龄、林分密度、林木株行距、接种肉苁蓉方式以及管理措施等基本一致的梭梭人工林为试验地,开展肉苁蓉采挖坑对坑侧土壤水分和采挖肉苁蓉后不回填采挖坑、采挖肉苁蓉后回填采挖坑、不采挖肉苁蓉(对照)等对梭梭根际土壤水分影响的研究。结果表明:采挖肉苁蓉后形成的采挖坑对坑侧土壤水分具有明显的影响,其影响范围因土壤层次而异。在0~20cm的土层内,离采挖坑越近,土壤含水率越低;在20cm以下的土层中,这种变化趋势依然存在,但在距采挖坑45cm处以远,土壤含水率受采挖坑的影响逐渐减弱。肉苁蓉采挖坑不同处理方式之间的土壤含水率存在显著差异。在0~10cm土层内,土壤含水率从大到小的排列次序是:对照>回填坑侧>回填坑内>不回填坑侧;在10~30cm土层内,回填坑侧>对照>回填坑内>不回填坑侧;在30~50cm土层内,对照>回填坑内>回填坑侧>不回填坑侧。不回填坑侧土壤含水率低的主要原因是采挖坑增加了土壤水分蒸发的界面,使深层土壤直接暴露于大气之中,从而引起采挖坑坑壁土壤水分不断蒸发所致;采挖肉苁蓉后回填采挖坑,可以延缓或阻止坑侧土壤水分向大气中扩散,但是,由于回填土的土壤结构在回填过程中已经发生改变,所以回填土的土壤含水率随时间的变化与未破坏土壤结构的对照、回填坑侧以及不回填坑侧的土壤含水率随时间的变化规律并不完全一致。By selecting an experiment plot from the fine forest experiment station in Jimusaer County of Xinjiang Uygur Autonomous Region,where the site conditions,way of inoculation Cistanche deserticola age of host sapling,planting sapling density were well selected all analogous in the fine tree seeds production base of Cistanche deserticola,we have studied the effect of different excavation hole treatments on soil moisture content around Haloxylon ammodendron rhizosphere. The results showed that the excavation hole resulted from Cistanche deserticola excavation had significant effect on the soil moisture content, with an influence range differing in soil layers. At the level of 0NFA4820 cm surface soil, the effect was most significant. The soil closer to the excavation hole had less moisture content. In the soil layer of more than 20 cm below the ground, this changing trend still existed. However, locations of more than 45 cm apart from the excavation hole, the influence of excavation hole on soil moisture content became less. The soil moisture content of different Cistanche deserticola excavation hole treatments existed significant differences. In the soil layer of 0NFA4810 cm, the ranking of soil moisture content in descending order was as follows: the control group > backfill excavation hole side > inner backfill excavation hole > non-backfill excavation hole side. In the soil layer of 10NFA4830 cm, the ranking of soil moisture content in descending order was as follows: backfill excavation hole side > the control group > inner backfill excavation hole > non-backfill excavation hole side. In the soil layer of 30NFA4850 cm,the ranking of soil moisture content in descending order was as follows: the control group > inner backfill excavation hole > backfill excavation hole side > non-backfill excavation hole side. The main reason for a low water moisture content in non-backfill excavation hole was that excavation increased the evaporation profile and exposure of deep layer soil to atmosphere, mak
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