摘要
鄂尔多斯高原砒砂岩区土壤贫瘠、水土流失强烈,土壤氮素养分也是该区域植被恢复重建的主要限制因子。该研究以3种乡土种芨芨草(Achnatherum splendens)、长柄扁桃(Amygdalus pedunculata)和沙棘(Hippophae rhamnoides)与2种外来种掌叶大黄(Rheum palmatum)和杂交狼尾草(Pennisetum americanum×P.purpureum)为研究对象,采用田间试验方法,分析比较鄂尔多斯砒砂岩区5种潜在适生植物在4个施氮水平[对照N_(0)、低(N L,0.1 g N/kg风干土)、中(N_(M),0.2 g N/kg风干土)、高(N_(H),0.3 g N/kg风干土)]下个体生长表现和氮素利用相关指标的差异,旨在从氮素利用角度以及物种选择与施氮干预两方面为区域植被恢复重建提供理论依据。结果表明:(1)5种植物的个体生长表现在中等施氮水平下最佳,试验期间掌叶大黄、芨芨草、长柄扁桃、杂交狼尾草和沙棘在中等施氮水平下的株高和生物量分别增加10.00、41.41、38.95、151.45、41.08 cm和52.84、60.55、75.36、668.67、142.86 g。(2)5种植物在4个氮素水平下的平均氮素利用效率(NUE)为1154.42 g·g^(-1),各施氮水平下,沙棘、掌叶大黄、长柄扁桃、杂交狼尾草和芨芨草的NUE分别为1546.16、1429.45、1389.75、731.09、675.65(g·g^(-1)),且5种植物的NUE存在显著的种间差异,各施氮水平下植物的NUE综合表现为:沙棘、掌叶大黄、长柄扁桃大于杂交狼尾草、芨芨草。(3)氮素水平对5种植物NUE的影响显著,以中等施氮下最高,且5种植物不同施氮水平的NUE综合表现为:中氮>对照、高氮>低氮。(4)在影响NUE的两种乘项构成因素中,5种植物因生活型等方面的差异呈现出较为明显的氮素生产力(NP)和平均滞留时间(MRT)间的权衡,其中作为速生植物类引进的杂交狼尾草倾向于通过提高氮素生产力来提高氮素利用效率;而大型灌木类本地种——沙棘和长柄扁桃则偏向于通过提高滞留时间来提高氮素利用效率。研究认为,在砒砂岩区植被恢复物种选择和施氮干预中,建议栽植沙棘和长柄扁桃;并且适度施氮有助于提高区域适生植物氮素利用效率,促进植被恢复重建。
The soil is poor and soil erosion is strong in the sandstone area of Ordos Plateau,and soil nitrogen literacy is also the main limiting factor of vegetation restoration and reconstruction in this area.The study included three native species of Achnatherum splendens,Amygdalus pedunculata and Hippophae rhamnoides,and two exotic species of Rheum palmatum and Pennisetum americanum×P.purpureum as the subject.Using field test methods,we analyzed and compared the differences of individual growth performance and nitrogen utilization related indicators with these five potentially suitable plants in 4 nitrogen-applying levels[control N_(0),low nitrogen(N L,0.1 g N/kg),medium nitrogen(N_(M),0.2 g N/kg)and high nitrogen(N_(H),0.3 g N/kg),The difference between individual growth performance and nitrogen utilization-related indicators under(NH,0.3 g N/kg air dry soil)Differences in individual growth performance and nitrogen utilization related indicators under air-dried soil].The aim is to provide theoretical basis for regional vegetation restoration and reconstruction from the perspective of nitrogen utilization and species selection and nitrogen application intervention.The results showed that:(1)the individual growth performance of the five plants was the best under the medium nitrogen level compared to other nitrogen levels.When the R.palmatum,A.splendens,A.pedunculata,P.americanum×P.purpureum and H.rhamnoides were at the medium nitrogen level,the plant height and biomass increased by 10.00,41.41,38.95,151.45,41.08 cm and 52.84,60.55,75.36,668.67,142.86 g,respectively.(2)The average nitrogen utilization efficiency(NUE)of 5 plants at 4 nitrogen levels was 1154.42 g·g^(-1),under each nitrogen level,the NUEs of H.rhamnoides,R.palmatum,A.pedunculata,P.americanum×P.purpureum and A.splendens are 1546.16,1429.45,1389.75,731.09,675.65 g·g^(-1),respectively;there are significant differences in NUE among the five plants.The comprehensive NUE performance of the plants at each nitrogen level is:H.rhamnoides,A.pedunculata,R.palmatum>P.americanum×P.purpureum,A.splendens.(3)The effect of nitrogen level on NUE in 5 plants was significant.The highest under medium nitrogen application,and the NUE of different nitrogen application levels in 5 plants was shown as:medium nitrogen>control,high nitrogen>low nitrogen.(4)Among the two multiplying factors that affect NUE,five plants showed a clear trade-off between nitrogen productivity(NP)and residence time(MRT)due to differences in life forms.Among them,P.americanum×P.purpureum introduced as a fast-growing plant tends to increase nitrogen use efficiency by increasing nitrogen productivity;while native species of large shrubs,H.rhamnoides and A.pedunculata tend to increase nitrogen use efficiency by increasing residence time.According to the research,it is suggested to plant H.rhamnoides and A.pedunculata in the selection of vegetation restoration species and nitrogen intervention in the sandstone area,and the moderate nitrogen use can help improve the efficiency of nitrogen utilization of regional suitable plants and promote vegetation restoration and reconstruction.
作者
秦晶晶
杜峰
杨路
程帅
李宏斌
QIN Jingjing;DU Feng;YANG Lu;CHENG Shuai;LI Hongbin(Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,CAS&MWR,Yangling,Shaanxi 712100,China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2021年第5期828-837,共10页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家重点研发计划项目(2017YFC0504504)
国家自然科学基金(41771322)。
关键词
氮素生产力
氮素滞留时间
氮素利用效率
物种选择
nitrogen productivity
nitrogen mean residence time
nitrogen use efficiency
species selection
