Effects of nitrogen addition and planting density on the growth and biological nitrogen fixation of Lespedeza davurica
Yin-Liu WANG1,2, Qian-Qian GENG1,2, Jian-Hui HUANG,,1,2,*, Chang-Hui WANG1, Lei LI1,2, Muqier HASI1,2, Guo-Xiang NIU1,21State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 2College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
Abstract Aims Nitrogen (N) supply and planting density are two important factors influencing plant growth. Legumes are important to ecosystem N input because of their capacity of biological N2 fixation (BNF). Increasing atmospheric N deposition may promote the growth of leguminous plants, but it may also inhibit strongly their BNF capacity. Planting density can also influence the growth and BNF capacity of legumes due to intraspecific competition. However, few studies up to date have focused on the effects of N fertilization and planting density on the growth and BNF capacity of legumes. In this study, we aimed to explore the potentially interactive effects of N fertilization and planting density on the growth and BNF capacity of Lespedeza davurica, a leguminous plant species which is widely distributed throughout the northern China grasslands. Methods A pot experiment was conducted in a greenhouse. The experiment contained four levels of N addition (0, 5, 10, 20 g·m-2·a-1) by NH4NO3fertilizer and three levels of planting densities (1, 3, 6 Ind.·pot-1, i.e. 32, 96, 192 Ind.·m-2). Important findings 1) Our results showed that both N addition and planting density could impact the biomass production ofL. davurica. N addition increased plant leaf carbon (C) and N contents and leaf-level net photosynthetic rate. Besides, N addition also stimulated the plant growth at both pot and individual levels, and the yield reached maximum at N addition of 10 g·m-2·a-1. Increasing planting density decreased leaf C and N contents, leaf-level net photosynthetic rate, and individual growth, but increased total biomass in each pot. 2) Nitrogen addition reduced the capacity of BNF of L. davurica, while increasing planting density could weaken this suppression effect to some extent. The combination of N addition of 10 g·m-2·a-1 and planting density of 3 Ind.·pot-1 or N addition of 10 g·m-2·a-1 and planting density of 6 Ind.·pot-1 could maximize the effects of N application on individual yield and the effects of increasing planting density on the alleviation of BNF suppression. Nitrogen addition suppressed the BNF of L. davurica through reducing plant investment to nodulation and nodule biomass production. The intraspecific competition and resource limitation caused by increasing planting density led to improvement in the investment to nodulation and nodule growth. 3) Structural equation model analyses showed that N addition and planting density combined explained variations in the plant biomass and nodule production either directly or indirectly by 64% and 42%, respectively. The results indicate that it is important to optimize the amount of fertilizer application and appropriate planting density when considering plantation and management of artificial and degraded grasslands. Keywords：N addition;planting density;biomass;nodule biomass;investment to nodulation;biological nitrogen fixation
PDF (1154KB)元数据多维度评价相关文章导出EndNote|Ris|Bibtex收藏本文 引用本文 王银柳, 耿倩倩, 黄建辉, 王常慧, 李磊, 哈斯木其尔, 牛国祥. 氮肥和种植密度对达乌里胡枝子的生长与生物固氮的影响. 植物生态学报, 2021, 45(1): 13-22. DOI: 10.17521/cjpe.2020.0185 WANG Yin-Liu, GENG Qian-Qian, HUANG Jian-Hui, WANG Chang-Hui, LI Lei, HASI Muqier, NIU Guo-Xiang. Effects of nitrogen addition and planting density on the growth and biological nitrogen fixation of Lespedeza davurica. Chinese Journal of Plant Ecology, 2021, 45(1): 13-22. DOI: 10.17521/cjpe.2020.0185
氮(N)是植物生长和发育所必需的重要养分元素(LeBauer & Treseder, 2008), 同时也是陆地生态系统生产力的限制性元素(Vitousek & Howarth, 1991; Elser et al., 2007)。自工业革命以来, 人类活动导致的大气氮沉降日益增加(Galloway et al., 2004, 2008), 这在缓解生态系统的氮限制的同时也改变了生态系统的结构和功能(Pardo et al., 2011; Midolo et al., 2019)。对豆科植物而言, 由于其生物固氮功能在受到氮限制的生态系统中占有重要地位(Vitousek et al., 2013), 但通过共生固氮获取大气中的氮是一个高耗能的过程(Gutschick, 1981), 大气氮沉降的增加以及草原管理中氮肥的施用提高了土壤中可利用氮的含量(潘庆民等, 2005; Liu et al., 2013), 这为豆科植物提供了一个相对“便宜”的氮源, 豆科植物可能会调整其对氮的利用方式以及对生物固氮的投资来保持其在群落中的竞争能力(Mengeet al., 2009)。目前关于豆科植物对氮响应的研究已经有很多, 但不同物种的生长和生物固氮对氮水平的响应并不一致(Guinet et al., 2018), 例如Regus等(2017)发现氮沉降显著降低了豆科植物Acmispon strigosus的根瘤数量和生物量, 而Drake (2011)的研究表明施氮会显著促进豆科植物生长, 同时对生物固氮没有抑制作用。因此, 结合具体豆科植物生物固氮和生长情况对土壤氮供给水平的响应, 可以评价豆科植物在氮沉降或草原施氮管理背景下群落中重要性的变化。
密度依赖性引起的植株正或负相互作用普遍存在于植物种群中, 选择合适的种植密度是建植和管理人工草地的关键(Japhet et al., 2009; 张炜平和王根轩, 2010)。低密度下单个植株的生长空间较大, 资源充足, 但群体产量受到个体数量限制。相反, 密度增加提高群体产量的同时也会导致群落内资源竞争增加(Weiner et al., 2001), 影响单个植株的生长发育和干物质积累(Chu et al., 2008; 列志旸等, 2016), 并改变生物量分配(赵宏魁等, 2016)。
氮肥添加对植物个体株高无显著影响(FN(3,48) = 1.47,p >0.05), 但对总生物量(FN(3,48) = 11.56,p <0.001)、总地上生物量(FN(3,48) = 11.60,p <0.001)、总地下生物量(FN(3,48) = 8.70,p <0.001)、平均地上生物量(FN(3,48) = 7.73,p <0.001)、平均地下生物量(FN(3,48) = 5.43,p <0.01)以及根冠比(FN(3,48) = 3.32,p <0.05)均存在显著影响(p< 0.05), 除根冠比外其他指标均随施氮量的增加呈现上升的趋势。种植密度处理则对所有的生长指标均有显著作用, 其中总生物量(Fd(2,48) = 69.67, p <0.001)、总地上生物量(Fd(2,48) = 61.95, p <0.001)、总地下生物量(Fd(2,48) = 32.10, p <0.001)以及根冠比(Fd(2,48) = 13.95, p <0.001)均随种植密度增加呈增加趋势, 而株高(Fd(2,48) = 15.90, p <0.001)、平均地上生物量(Fd(2,48) = 168.03, p <0.001)和平均地下生物量(Fd(2,48) = 10.69, p <0.001)则随密度增加呈现降低趋势(表1)。
Table 1 表1 表1不同氮肥和种植密度处理下达乌里胡枝子的生长指标(平均值±标准误) Table 1Growth indexes of Lespedeza davurica under different levels of nitrogen addition and planting density treatments (mean ± SE)
处理 Treatment
水平 Level
株高 Height (cm)
总生物量 Total biomass (g)
总地上生物量 Total aboveground biomass (g)
总地下生物量 Total belowground biomass (g)
平均地上生物量 Average aboveground biomass (g·Ind.-1)
平均地下生物量 Average belowground biomass (g·Ind.-1)
根冠比 Root:shoot ratio
叶片C含量 Leaf C concentration (%)
施氮 N addition (g·m-2·a-1)
0
58.69 ± 2.14 ns
11.79 ± 1.02 b
8.94 ± 0.72 c
2.84 ± 0.32 b
3.61 ± 0.47 b
1.06 ± 0.13 b
0.31 ± 0.02 b
45.26 ± 0.34 b
5
58.49 ± 1.90 ns
15.43 ± 1.02 a
11.24 ± 0.64 bc
4.20 ± 0.39 a
4.93 ± 0.76 a
1.67 ± 0.22 a
0.36 ± 0.02 a
45.99 ± 0.35 a
10
62.56 ± 2.43 ns
15.76 ± 1.04 a
11.99 ± 0.77 a
3.76 ± 0.32 a
5.20 ± 0.80 a
1.60 ± 0.25 a
0.31 ± 0.02 b
45.98 ± 0.32 a
20
63.32 ± 2.61 ns
15.37 ± 1.02 a
11.52 ± 0.7 ab
3.86 ± 0.33 a
4.91 ± 0.67 a
1.51 ± 0.17 a
0.33 ± 0.01 ab
45.95 ± 0.26 a
密度 Planting density (Ind.·pot-1)
1
77.53 ± 4.43 a
10.01 ± 0.62 b
7.80 ± 0.45 b
2.20 ± 0.19 b
7.81 ± 0.45 a
2.20 ± 0.19 a
0.28 ± 0.01 b
46.29 ± 0.09 a
3
61.56 ± 1.60 b
16.54 ± 0.62 a
12.20 ± 0.46 a
4.34 ± 0.19 a
4.07 ± 0.15 b
1.45 ± 0.06 b
0.36 ± 0.01 a
46.69 ± 0.24 a
6
57.53 ± 1.42 b
17.50 ± 0.55 a
12.94 ± 0.38 a
4.56 ± 0.25 a
2.16 ± 0.06 c
0.76 ± 0.04 c
0.35 ± 0.02 a
44.41 ± 0.13 b
N × density
**
***
***
***
***
***
***
ns
同列不同小写字母表示氮或密度处理下差异显著(p< 0.05), ns表示差异不显著(p> 0.05)。*,p< 0.05; **,p< 0.01; ***,p< 0.001。 Different lowercase letters in the same column indicate significant difference among N addition levels or density treatments at p< 0.05 level, while ns indicates no significant difference. *,p< 0.05; **,p< 0.01; ***,p< 0.001.
新窗口打开|下载原图ZIP|生成PPT 图1不同处理下达乌里胡枝子的叶片N含量(A)和净光合速率(B)的变化(平均值±标准误)。不同小写字母表示同一密度下不同施氮量间差异显著(p < 0.05), 不同大写字母表示不同密度下差异显著(p < 0.05)。ns, p > 0.05; *, p < 0.05; **, p < 0.01; ***, p < 0.001。
Fig. 1Changes in leaf nitrogen (N) concentration (A) and net photosynthetic rate (B) of Lespedeza davurica under different treatments (mean ± SE). Different lowercase letters indicate significant difference among N addition treatments under the same density at p < 0.05 level, while different uppercase letters indicate significant difference among density treatments at p < 0.05 level. ns, p > 0.05; *, p < 0.05; **, p < 0.01; ***, p < 0.001.
新窗口打开|下载原图ZIP|生成PPT 图2不同处理下达乌里胡枝子的相对邻株效应指数(平均值±标准误)。不同小写字母表示同一施氮量下不同密度下差异显著(p < 0.05)。ns, p > 0.05; *, p < 0.05; **, p < 0.01; ***, p < 0.001。
Fig. 2Relative neighbor effect index under different treatments (mean ± SE). Different lowercase letters indicate significant difference among density treatments under the same N addition rate at p < 0.05 level. ns, p > 0.05; *, p < 0.05; **, p < 0.01; ***, p < 0.001.
新窗口打开|下载原图ZIP|生成PPT 图3不同处理对根瘤生物量响应比(RR)(A)和根瘤投资(B)的影响(平均值±标准误)。图A中,虚线位置代表RR = 1, 如果误差线没有跨越虚线表示处理与对照存在显著差异(p < 0.05)。*, p < 0.05; **, p < 0.01; ***, p < 0.001。
Fig. 3Responses of the nodule biomass response ratio (RR)(A) and investment to nodulation (B) under different treatments (mean ± SE). In Fig. A, response ratio values with error bars not overlapping RR = 1 (horizontal dotted line), indicate significant difference between treatment and control (p < 0.05). *, p < 0.05; **, p < 0.01; ***, p < 0.001.
Fig. 4Direct and indirect impacts of N addition rate and planting density on the root nodulation and growth of Lespedeza davurica. Lines indicate a significant effect (p < 0.05). Line thickness indicates relative effect size. Black lines represent positive effects, while gray lines indicate negative effects. R 2 indicates variation that can be explained. Pn, net photosynthetic rate.
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Comparative effect of inorganic N on plant growth and N 2 fixation of ten legume crops: towards a better understanding of the differential response among species 1 2018
... 氮(N)是植物生长和发育所必需的重要养分元素(LeBauer & Treseder, 2008), 同时也是陆地生态系统生产力的限制性元素(Vitousek & Howarth, 1991; Elser et al., 2007).自工业革命以来, 人类活动导致的大气氮沉降日益增加(Galloway et al., 2004, 2008), 这在缓解生态系统的氮限制的同时也改变了生态系统的结构和功能(Pardo et al., 2011; Midolo et al., 2019).对豆科植物而言, 由于其生物固氮功能在受到氮限制的生态系统中占有重要地位(Vitousek et al., 2013), 但通过共生固氮获取大气中的氮是一个高耗能的过程(Gutschick, 1981), 大气氮沉降的增加以及草原管理中氮肥的施用提高了土壤中可利用氮的含量(潘庆民等, 2005; Liu et al., 2013), 这为豆科植物提供了一个相对“便宜”的氮源, 豆科植物可能会调整其对氮的利用方式以及对生物固氮的投资来保持其在群落中的竞争能力(Mengeet al., 2009).目前关于豆科植物对氮响应的研究已经有很多, 但不同物种的生长和生物固氮对氮水平的响应并不一致(Guinet et al., 2018), 例如Regus等(2017)发现氮沉降显著降低了豆科植物Acmispon strigosus的根瘤数量和生物量, 而Drake (2011)的研究表明施氮会显著促进豆科植物生长, 同时对生物固氮没有抑制作用.因此, 结合具体豆科植物生物固氮和生长情况对土壤氮供给水平的响应, 可以评价豆科植物在氮沉降或草原施氮管理背景下群落中重要性的变化. ...
Evolved strategies in nitrogen acquisition by plants 1 1981
... 氮(N)是植物生长和发育所必需的重要养分元素(LeBauer & Treseder, 2008), 同时也是陆地生态系统生产力的限制性元素(Vitousek & Howarth, 1991; Elser et al., 2007).自工业革命以来, 人类活动导致的大气氮沉降日益增加(Galloway et al., 2004, 2008), 这在缓解生态系统的氮限制的同时也改变了生态系统的结构和功能(Pardo et al., 2011; Midolo et al., 2019).对豆科植物而言, 由于其生物固氮功能在受到氮限制的生态系统中占有重要地位(Vitousek et al., 2013), 但通过共生固氮获取大气中的氮是一个高耗能的过程(Gutschick, 1981), 大气氮沉降的增加以及草原管理中氮肥的施用提高了土壤中可利用氮的含量(潘庆民等, 2005; Liu et al., 2013), 这为豆科植物提供了一个相对“便宜”的氮源, 豆科植物可能会调整其对氮的利用方式以及对生物固氮的投资来保持其在群落中的竞争能力(Mengeet al., 2009).目前关于豆科植物对氮响应的研究已经有很多, 但不同物种的生长和生物固氮对氮水平的响应并不一致(Guinet et al., 2018), 例如Regus等(2017)发现氮沉降显著降低了豆科植物Acmispon strigosus的根瘤数量和生物量, 而Drake (2011)的研究表明施氮会显著促进豆科植物生长, 同时对生物固氮没有抑制作用.因此, 结合具体豆科植物生物固氮和生长情况对土壤氮供给水平的响应, 可以评价豆科植物在氮沉降或草原施氮管理背景下群落中重要性的变化. ...
Impacts of nitrogen addition on plant biodiversity in mountain grasslands depend on dose, application duration and climate: a systematic review 1 2016
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,1,2,*, 王常慧1, 李磊1,2, 哈斯木其尔1,2, 牛国祥1,2
新窗口打开|下载原图ZIP|生成PPT
新窗口打开|下载原图ZIP|生成PPT
新窗口打开|下载原图ZIP|生成PPT
新窗口打开|下载原图ZIP|生成PPT
