模拟氮沉降对亚热带栎属树种幼苗生长、生物量累积及光合特性的影响  

Effects of simulated nitrogen deposition on growth, biomass accumulation and photosynthetic characteristics responses of Quercus seedlings in Mid-subtropics of China

作　　者：王晓荣[1] 潘磊[1] 庞宏东[1] 郑京津[1] 王瑞文[1] 

机构地区：[1]湖北省林业科学研究院,湖北武汉430075

出　　处：《中南林业科技大学学报》2016年第1期78-85,共8页Journal of Central South University of Forestry & Technology

基　　金：国家林业公益性行业项目(201304308)

摘　　要：设置模拟氮沉降的控制试验,以NH4NO3作为外加氮源,模拟氮沉降变化,设置CK、N5、N15和N30(分别相当于氮沉降0、5、15和30 g·m-2a-1)4个处理,历时2 a,研究氮沉降对小叶栎、麻栎、栓皮栎、白栎和短柄枹栎幼苗生长、光合特性以及生物量累积和分配的影响。结果表明:(1)随着氮沉降浓度的逐渐增加,麻栎、栓皮栎和短柄枹栎的株高显著增高,中高浓度氮显著促进了栓皮栎和麻栎地径的增加。(2)栎类不同树种利用光能的程度存在较大差异,除麻栎外,小叶栎、栓皮栎、白栎和短柄枹栎幼苗的最大净光合速率、表观量子速率和光饱和点随氮处理水平增加呈先增加后降低的趋势,在N15水平达到最高。小叶栎和麻栎的光补偿点和暗呼吸速率随氮沉降浓度增加呈逐渐增加,栓皮栎和短柄枹栎呈先增加后降低,而白栎则为逐渐降低的趋势。除栓皮栎和麻栎外,氮沉降对白栎、短柄枹栎和小叶栎叶绿素α、叶绿素b和叶绿素α+b含量均表现出显著的促进作用,但不同处理间差异不显著。(3)栎属5个树种生物量均表现随氮沉降浓度增加而增加的趋势,不同栎类树种生物量分配格局受氮沉降影响存在差异。叶重比受影响均不显著,中高氮水平促进麻栎和小叶栎的枝重比以及短柄枹栎和栓皮栎的干重比明显增加。5种树种幼苗根冠比显著降低,且氮沉降浓度越高越明显。To clarify the effects of nitrogen deposition on the growth, photosynthetic characteristics and biomass accumulation and distribution of Quercus chenii, Q. acutissima, Q. variabilis, Q. fabri and Q. glandulifera var. brevipetiolata seedlings, a two-year term control experiment were conducted, in which NH4NO3 was added as the external nitrogen sources （four nitrogen depositions （O （CK）, 5 g·m^-2a^-1（N5）, 15 g·m^-2a^-1（N15） and 30 g·m^-2a^-1 （N30））. The results show that （1） With increased nitrogen deposition levels, plants heights of Q. acutissima, Q. variabilis and Q. glandulifera var. brevipetiolata increased significantly, and medium and high concentrations of nitrogen deposition significantly promotes the diameter growth of Q. acutissima and Q. variabilis. （2） Light utilization efficiency of Quercus differed from each other species. Except Q. acutissima, maximum net photosynthetic rate, apparent quantum rate and light saturation point of Q. chenii, Q. variabilis, Q. fabri and Q. glandulifera var. brevipetiolata firstly increased, the peak was at the N15 level, then decreased; Meanwhile, light compensation point and respiration rate of Q. chenii and Q. acutissima increased gradually; in contrast, light compensation point and respiration rate of Q. fabri decreased, while on Q. variabilis and Q. glandulifera var. brevipetiolata increased at first and then decreased; Nitrogen deposition significantly favor the content increase of chlorophyll a, chlorophyll b and chlorophyll a＋b in Q. fabri, Q. glandulifera var. brevipetiolata and Q. chenii, regardless of the nitrogen deposition levels. （3） As for the biomass accumulation in Quercus, regardless of the species, they gradually increased with the increase of nitrogen deposition level; however, biomass distribution in different species of Quercus significantly differed from nitrogen deposition levels, while the effects of nitrogen deposition levels on leaf weight ratio were insignificant; medium and high nitrogen levels increased

关 键 词：栎属树种 亚热带 模拟氮沉降 幼苗生长 生物量累积 光合参数 

分 类 号：S792.18[农业科学—林木遗传育种]