Subjects: Geosciences >> Geography submitted time 2024-07-04 Cooperative journals: 《干旱区研究》
Abstract： Soil nitrogen mineralization is a key process of soil nitrogen cycle, and temperature is one of the most important factors affecting soil nitrogen mineralization. Studying the effect of temperature on soil nitrogen mineralization characteristics in different successional stages is of great significance for understanding soil nitrogen cycle in terrestrial ecosystems. In this study, the communities in different successional stages of Xinglong Mountain in Gansu Province were taken as the research object. The indoor constant temperature aerobic culture method was used to study the soil nitrogen mineralization characteristics of five successional stages (grassland, shrub forest, Betula platyphylla forest, Picea wilsonii-Betula platyphylla forest and Picea wilsonii forest) under different temperatures (15 ℃, 25 ℃, 35 ℃). The results showed that: (1) Except for the 0~20 cm soil depth of grassland, the soil nitrogen mineralization rate of the other successional stages increased with the increase of temperature (15~35 ℃), and the cumulative mineralization of soil nitrogen in different successional stages increased with the increase of temperature. (2) With the positive advancement of succession, the soil nitrogen mineralization rate and cumulative mineralization amount of different successional stages showed a trend of increasing first and then decreasing. The soil nitrogen mineralization rate of Betula platyphylla forest was the highest, which was 1.63 times, 1.61 times, 1.25 times and 1.47 times that of grassland, shrub forest, Picea wilsonii-Betula platyphylla forest and Picea wilsonii forest, respectively. The soil nitrogen mineralization rate and cumulative mineralization amount of Picea wilsonii-Betula platyphylla forest were the highest, which were 0.68 times, 0.72 times, 0.84 times and 0.97 times of those of grassland, shrub forest, Betula platyphylla forest and Picea wilsonii forest, respectively. (3) With the increase of soil depth, the soil nitrogen mineralization rate and cumulative mineralization showed a decreasing trend, with the maximum in the 0~20 cm soil depth. (4) There were significant differences in the temperature sensitivity coefficient Q10 at 15 ℃ and 25 ℃ in different successional stages (P<0.05). With the positive succession, the temperature sensitivity coefficient Q10 decreased first and then increased. There was no significant difference in the temperature sensitivity coefficient Q10 between the communities at different succession stages at 25 ℃ and 35 ℃ (P>0.05). The results of this study will provide a theoretical basis for the evolution of soil quality and the dynamic change of soil nitrogen supply capacity in the community.
Subjects: Geosciences >> Geography submitted time 2021-04-23 Cooperative journals: 《干旱区研究》
Abstract：为探讨不同类型人工林对土壤理化性质的改良能力，以兰州市南北两山5种典型林分类型（侧柏林、新疆杨林、刺槐林、侧柏刺槐混交林、新疆杨刺槐混交林）为研究对象，对0~80 cm土层的土壤理化性质进行了研究。结果表明：（1）不同林分类型混交林土壤容重、持水量、孔隙度、土壤含水量、渗透速率均好于纯林；两种混交林和侧柏林土壤pH低于刺槐林和新疆杨林；混交林土壤有机质、全氮、无机氮、全磷大于纯林；全钾、速效钾在不同林分类型之间差异不显著。（2）在0~80 cm土层范围内，各林分类型随着土壤深度的增加，土壤容重逐渐增加；土壤持水量、孔隙度逐渐降低；土壤含水量、土壤pH均在土层间无显著差异；土壤有机质、全氮、无机氮、速效磷、速效钾随土壤深度的增加逐渐降低，有表聚效应；全磷和全钾在土层间差异不显著。（3）土壤理化性质相关性分析发现：土壤有机质与土壤全氮、无机氮、全磷、持水量、孔隙度均呈极显著正相关，与土壤容重呈极显著负相关；土壤容重与土壤持水量、孔隙度均呈极显著负相关。混交林较纯林在改善土壤理化性质方面有更好的效果，建议该区域在今后人工林营造中以混交林为主，在现有纯林的抚育管理中可考虑将其改造为混交林。
Subjects: Geosciences >> Geography submitted time 2020-12-17 Cooperative journals: 《干旱区研究》
Abstract：为选择抗旱优良的唐古特白刺家系，本实验于2015、2016年和2018年分别对来自兰州和武威试验点的31个唐古特白刺家系进行可溶性糖（SS）、可溶性蛋白（SP）、游离脯氨酸（Pro）、过氧化氢酶（CAT）、过氧化物酶（POD）、超氧化物歧化酶（SOD）以及叶绿素（Chl）含量测定，运用主成分分析法和隶属函数法对家系抗旱性进行综合评价选择出抗旱优良家系并进行对比分析。结果表明：运用2种综合评价方法结果重合率在80%以上，以20%入选率选择抗旱优良家系，2试验点的j3-9、jc-8、w3-15、w3-12等4个家系在2015年、2016年均入选，在2018年抗旱性明显优于其他家系，入选家系在不同年份不同试验点的抗旱性表现一致，说明唐古特白刺抗旱优良家系在不同生理阶段不同环境下抗旱性表现稳定，对其进行早期选择具有可靠性。
Hits
Hits
Downloads
Comment