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陕西长安和曲江人工林地土壤含水量对比研究 被引量:3
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作者 卢爱刚 董雯 赵景波 《水土保持研究》 CSCD 北大核心 2009年第3期155-158,163,共5页
根据长安地区苹果林地及曲江地区梧桐林地和杨树林地土壤含水量测定,研究了0-6 m土壤含水量的变化和土壤干层的恢复。结果表明,在丰水年之后长安地区人工林地土壤含水量与正常年份土壤含水量有明显不同,12 a苹果林地2-4 m土层含水量平均... 根据长安地区苹果林地及曲江地区梧桐林地和杨树林地土壤含水量测定,研究了0-6 m土壤含水量的变化和土壤干层的恢复。结果表明,在丰水年之后长安地区人工林地土壤含水量与正常年份土壤含水量有明显不同,12 a苹果林地2-4 m土层含水量平均11.77%,14 a苹果林地平均15.27%;曲江地区丰水年之后12 a杨树林地2-4 m平均含水量18.53%,14 a梧桐林地2-4 m平均含水量17.24%,干层完全消失。这表明在降水量增加的条件下,黄土高原南部土壤干层中的水分完全可以恢复。长安与曲江地区丰水年之后经过约2年半的时间,人工林土层水分恢复深度可达到6 m左右。不同树种含水量差异较大,苹果林地干层带水分恢复比梧桐、杨树林明显低。 展开更多
关键词 关中平原 土壤干层 水分恢复 含水量差异
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丰水年后春季人工林地土壤含水量变化研究 被引量:1
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作者 董雯 杨秀英 韩晨 《湖北农业科学》 北大核心 2010年第12期3028-3032,共5页
通过对西安南郊吴家坟5种类型人工林地0~6m土壤含水量的测定,研究了该地区丰水年之后人工林地的土壤水分恢复状况和消耗过程,以及土壤水分的变化规律与影响因素等问题。结果表明,西安地区不同人工林下土壤含水量差异较大。15年法国梧... 通过对西安南郊吴家坟5种类型人工林地0~6m土壤含水量的测定,研究了该地区丰水年之后人工林地的土壤水分恢复状况和消耗过程,以及土壤水分的变化规律与影响因素等问题。结果表明,西安地区不同人工林下土壤含水量差异较大。15年法国梧桐林地土壤平均含水量为24.30%,10年中国梧桐林地土壤平均含水量为20.23%,15年雪松林地土壤平均含水量为13.52%,15年杨树林地平均土壤含水量为18.15%,13年中国槐林地土壤平均含水量为15.95%。造成人工林地土壤水分含量差异的主要原因是不同树种生长速度的快慢不同。 展开更多
关键词 西安南郊 人工林地 土壤干层 水分恢复 含水量差异
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圣诞贺卡生产中纸板曲翘问题的研究
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作者 陈科侠 徐将来 《纸和造纸》 2019年第5期5-8,共4页
针对以250 g·m-2纸杯原纸为原料生产圣诞贺卡过程中出现的贺卡曲翘问题,开展专题研究。据已有文献及过往技术经验分析贺卡曲翘的可能原因,并就环境温湿度对纸板的伸缩性、含水量及曲翘情况进行了实验,同时对已变形纸板压平恢复情... 针对以250 g·m-2纸杯原纸为原料生产圣诞贺卡过程中出现的贺卡曲翘问题,开展专题研究。据已有文献及过往技术经验分析贺卡曲翘的可能原因,并就环境温湿度对纸板的伸缩性、含水量及曲翘情况进行了实验,同时对已变形纸板压平恢复情况展开了实验。实验表明:湿度增加10%含水量增加约1%;30%到90%湿度变化中,横向伸缩率增加约1%,纵向增加约0.2%;不同湿度改变曲翘变化可达2倍;温度变化对曲翘影响很小;自然平衡下在最初3 h内恢复70%曲翘。纸板曲翘主因是两表面含水量不同引起受力不均,而控制较低湿度范围(30%~60%),保持生产环境温湿度稳定能有效控制贺卡曲翘。 展开更多
关键词 纸杯原纸 曲翘 含水量差异 湿度
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Recovery of Collembola in Pinus tabulaeformis Plantations 被引量:2
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作者 CHANG Liang WANG Baifeng +2 位作者 LIU Xianghui Mac A.CALLAHAM Jr. GE Feng 《Pedosphere》 SCIE CAS CSCD 2017年第1期129-137,共9页
Large areas of forest plantations have been developed in China. It is important to evaluate the soil fauna in plantations and the conditions needed for their recovery in view of the large areas of plantations in China... Large areas of forest plantations have been developed in China. It is important to evaluate the soil fauna in plantations and the conditions needed for their recovery in view of the large areas of plantations in China. Three Pinus tabulaeformis forests, a 26-year-old plantation (P26) and a 45-year-old plantation (P45), exposed to clear-cutting before plantation, and an 80 260-year-old natural forest (N260), were chosen to study the effects of different forest ages/types on Collembola community in the lifter and soil layers during 2008 and 2009. Soil conditions in P26 and P45 were significantly deteriorated when compared to N260. A higher value of soil bulk density and lower values of soil organic matter, soil N, litter depth, soil pH, and soil water content were observed in P26 and P45. Totally, the same genera of Collembola tended to occur in the forests of all ages studied; however, the Collembola community structure was significantly impacted by the differences in forest age. Both in the litter and soil layers, the density and generic richness of the Collembola were the highest in N260 and the lowest in P26. Some collembolan groups were sensitive to soil conditions in particular forest ages. N260 was associated with relatively high abundance of Plutomus collembolans and P45 with relatively high abundance of Pseudofolsomia collembolans. The canonical correspondence analysis showed that the community structure of Collembola was mainly affected by forest age in both litter and soil layer. The ordination analysis of non-metric multidimensional scaling also found that the Collembola community did not recover to the level of natural forests in 26-year regeneration after clear-cutting. Even in 45-year regeneration after clear-cutting, the Collembola community only showed a slight recovery to the level of natural forests. Our results clearly showed that both Collembola community and soil conditions did not recover in 26- and 45-year regeneration after clear-cutting in P. tabulaeforrnis plantations; however, they might have the potential to recover in the future because the same genera of Collembola were distributed in the plantations and natural forests. 展开更多
关键词 community structure forest age litter layer soil conditions soil fauna soil layer
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