单 位：
甘肃省治沙研究所甘肃省荒漠化与风沙灾害防治重点实验室—省部共建国家重点实验室培育基地;科罗拉多州立大学农业科学学院;中国林业科学研究院荒漠化研究所
关键词：
白刺灌丛沙堆;发育;防风功能;固沙功能;荒漠—绿洲过渡带
摘 要：
【目的】民勤荒漠—绿洲过渡带从沙漠边缘到绿洲外围依次形成了雏形阶段、发育阶段、稳定阶段和活化阶段4种不同发育阶段的天然白刺灌丛沙堆,各发育阶段沙堆的防风功能、固沙功能和综合功能如何变化并不清楚。本研究期望通过对它们的研究,为中国干旱区荒漠化防治和绿洲生态安全保障提供科技支撑。【方法】在对各发育阶段白刺灌丛沙堆的植被特征、形态特征、分布特征野外调查和观测的基础上,采用统计分析和数值计算,对各发育阶段灌丛沙堆的防风功能、固沙功能以及综合功能值进行了分析阐述。【结果】(1)白刺灌丛沙堆的整体生长状况和植被覆盖度均随发育过程的进行呈先升高后降低的态势,发育阶段植被生长状况最好,而活化阶段生长状况最差(P<0.01);稳定阶段植被覆盖度显著高于其他阶段(P<0.01),而雏形阶段最低(P<0.01);沙堆体积大小随底面积的增加而逐渐增加;(2)不同发育阶段单株白刺灌丛的防风、固沙功能值变化趋势相似,大小排序为活化阶段>发育阶段>稳定阶段>雏形阶段;而样地内纵断面单位面积上防风功能为稳定阶段>活化阶段>发育阶段>雏形阶段,固沙功能为活化阶段>发育阶段>稳定阶段>雏形阶段,因此,其防风固沙综合功能发生了变化,功能值大小分别为稳定阶段>活化阶段>发育阶段>雏形阶段。【结论】民勤荒漠—绿洲过渡带白刺沙堆防风固沙综合功能值总体上随发育过程的进行而呈增加的趋势,表明从雏形阶段到活化阶段防风固沙功能逐渐增强。虽然活化阶段沙堆表现出退化现象,但是仍旧具有很好的防风固沙功效,对维护绿洲边缘生态安全具有重要的防护作用,应进一步加强退化沙堆的保护和抚育更新工作。
译 名：
Comparison on Functions of Wind-Break and Sand-Fixation of Nitraria Tangutorun Nebkhas at Different Developmental Stages in Minqin Desert-oasis Transition Zone
作 者：
SUN Tao;JIA Zhiqing;QIAN Yaling;LIU Hujun;TANG Jinnian;Institute of Desertification Studies, Chinese Academy of Forestry Sciences;Gansu Desert Control and Research Institute, State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating;College of Agricultural Sciences, Colorado State University;
关键词：
Nitraria tangutorun Nebkhas;;development;;wind-prevention function;;sand-fixation function;;desert-oasis transition zone
摘 要：
[Purpose]A large area of natural vegetation dominated by Nitraria tangutorun nebkhas is widely distributed in Minqin desert-oasis transition zone. The communities of N. tangutorun nebkhas in 4 developmental stages are formed from the edge of the desert to the periphery of the oasis of Minqin, including the embryonic stage, the development stage, the stable stage and the activating stage, respectively. While, there were different functions of wind prevention and sand-fixing in each developmental stage. Through this study and experiment, to clarify the change of functions of wind prevention, fixing sand and the differences among those stages along with the process of development.[Method] The vegetation characteristics, morphological characteristics and distribution characteristics had been investigated in the field to examine the functions of wind prevention and sand-fixing by using statistical analysis and numerical calculations, to compare the wind-break function, sandfixing function and the comprehensive function of nebkhas in different developmental stages.[Result](1) The growth status and vegetation coverage of nebkhas increased at first then decreased with the processing developmental stages, the vegetation growth status was the best at the developing stage and worst in the activating stage(P<0.01); while, the vegetation coverage was the highest at the stable stage(P<0.01) and the lowest at the embryonic stage(P<0.01); also, the volume of nebkhas gradually increased with the increasing of the bottom area.(2) The function of wind prevention of a single nebkhas was decreased in the following order: activating>development>stable>embryonic stages, the trend of the function of sand-fixing of a single nebkhas was the same order as that of wind-break function. The function of wind prevention per unit area at vertical section in different developmental stages was decreased from high to low as following order: activating>development>stable>embryonic stages; while, the comprehensive function of wind-break and sand-fixing per unit area at vertical section of plots in different developmental stages was declined from high to low as order: stable >activating>development>embryonic stages.[Conclusion]The comprehensive function of wind-break and sand-fixation increased with the process of developmental stages, indicating that the function of wind-break and sand-fixation gradually increased from the embryonic stage to the activating stage.Although the nebkhas of N. tangutorun in the activating stage shows degradation, it still has a good function of wind-break and sand-fixation and plays an important role in protecting the ecological security of the desert-oasis transition zone, and should further strengthen the protection and renewable cultivation of degraded vegetations.
