暖温带落叶阔叶林辽东栎和五角枫生长和光合生理生态特征对模拟氮沉降的响应

doi:10.17521/cjpe.2018.0303

摘要/Abstract

摘要：

暖温带落叶阔叶林在维护区域生态系统功能和平衡中起着重要的作用, 研究其在氮添加下的生长和生理生态响应, 有助于深入理解暖温带落叶阔叶林在全球氮沉降背景下的生长和变化规律。该研究通过在北京东灵山落叶阔叶林的模拟氮沉降控制实验, 以优势种辽东栎(Quercus wutaishanica)和伴生种五角枫(Acer pictum subsp. mono)为研究对象, 设置对照和氮添加2种处理, 每种处理4个重复, 对照样地不做处理; 氮添加样地施加尿素(CO(NH₂)₂), 总的氮添加量为100 kg·hm ^-2·a ^-1, 测定氮添加对其生长和光合生理生态特征的影响。结果显示: 氮添加显著提高了两个树种的净光合速率、蒸腾速率、叶绿素含量, 同时扩大了叶片光系统II反应中心电子传递体库, 增加了基于光合电子流驱动的初级受体醌(Q_A)被还原的周转次数。氮添加也增加了两个树种当年生枝条的长度和生物量, 同时在一定程度上提高了辽东栎种子的质量。辽东栎光合作用氮利用效率、枝条生物量对氮添加的响应程度明显超过五角枫。在未来氮沉降加剧的情景下, 东灵山暖温带落叶阔叶林优势种辽东栎的优势地位会进一步加强。

关键词: 氮沉降, 暖温带落叶阔叶林, 光合作用, 叶绿素荧光, 生长

Abstract:

Aims Warm-temperate deciduous broad-leaved forest plays an important role in maintaining regional ecosystem function and balance. To explore the growth and eco-physiological response to nitrogen (N) addition will deepen our understanding of its dynamic development under the scenario of global N deposition.

Methods A simulated N deposition experiment was established with four N addition plots (100 kg·hm ^-2·a ^-1) and four control plots in a deciduous broad-leaved forest in Dongling Mountain, Beijing. The responses of branch growth, photosynthesis, chlorophyll fluorescence and seed mass of dominant species Quercus wutaishanica and associate species Acer pictum subsp. mono to N addition were investigated.

Important findings Net photosynthetic rate, transpiration rate, and chlorophyll content were enhanced by the N addition. Furthermore, the N addition also enlarged the electron transport pool in photosystem II reaction center and increased the turnover number of the primary quinone acceptor (QA) reduction expressed by fast chlorophyll fluorescence method of JIP test in both species. The N addition also increased the length and biomass of the current year branches of the two tree species and improved the seed quality of Q. wutaishanica to a certain extent. In general, we observed more pronounced responses of photosynthetic nitrogen use efficiency, and branch biomass formation to N addition in Q. wutaishanica compared with A. pictum subsp. mono. Our results suggested that the dominant position of Q. wutaishanica should be further highlighted under increased N deposition scenario in the warm-temperate deciduous broad-leaved forest in Dongling Mountain.

Key words: nitrogen deposition, warm-temperate deciduous broad-leaved forest, photosynthesis, chlorophyll fluorescence, growth

刘校铭, 杨晓芳, 王璇, 张守仁. 暖温带落叶阔叶林辽东栎和五角枫生长和光合生理生态特征对模拟氮沉降的响应. 植物生态学报, 2019, 43(3): 197-207. DOI: 10.17521/cjpe.2018.0303

LIU Xiao-Ming, YANG Xiao-Fang, WANG Xuan, ZHANG Shou-Ren. Effects of simulated nitrogen deposition on growth and photosynthetic characteristics of Quercus wutaishanica and Acer pictum subsp. mono in a warm-temperate deciduous broad- leaved forest. Chinese Journal of Plant Ecology, 2019, 43(3): 197-207. DOI: 10.17521/cjpe.2018.0303

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链接本文: https://www.plant-ecology.com/CN/10.17521/cjpe.2018.0303

https://www.plant-ecology.com/CN/Y2019/V43/I3/197

图/表 5

Table 1 Effects of nitrogen (N) treatment, tree species and their interaction on some eco-physiological and growth traits of Quercus wutaishanica and Acer pictum subsp. Mono in Dongling Mountain

性状 Trait	氮 N	树种 Species	氮 × 树种 N × Species
净光合速率 Net photosynthetic rate (P_n)	***	***	***
气孔导度 Stomatal conductance (G_s)	***	***	***
蒸腾速率 Transpiration rate (T_r)	***	***	***
水分利用效率 Water use Efficiency (WUE)	ns	ns	ns
叶绿素含量 Chlorophyll contents (Chl)	***	***	ns
光系统II最大光化学效率 Maximal PSII efficiency (PHI(Po))	ns	ns	ns
光系统II电子传递链电子受体库大小 PSII size of Q_A pool (S_m)	***	ns	ns
初级醌受体被还原周转次数 PSII Q_A reduced turn over number (N)	***	**	ns
光合氮利用效率 Photosynthetic nitrogen use efficiency (PNUE)	ns	ns	**
当年生枝长度 Length of current year branch	***	*	ns
当年生枝生物量 Biomass of current year branch	*	***	ns
辽东栎种子质量 Quercus wutaishanica seed mass	ns	-	-

图1 氮处理随季节变化对东灵山辽东栎(A-D)和五角枫(E-H)光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和水分利用效率(WUE)的影响(平均值±标准偏差)。***, p ＜ 0.001; **, p ＜ 0.01; *, p ＜ 0.05; ns, p ＞ 0.05。

Fig. 1 Seasonal changes of net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and water use efficiency (WUE) of Quercus wutaishanica (A-D) and Acer pictum subsp. mono (E-H) in Dongling Mountain in response to nitrogen treatment (mean ± SD). ***, p ＜ 0.001; **, p ＜ 0.01; *, p ＜ 0.05; ns, p ＞ 0.05.

图2 氮处理对辽东栎(A)和五角枫(B)叶绿素含量(Chl)的季节性影响(平均值±标准偏差)。**, p ＜ 0.01; *, p ＜ 0.05; ns, p ＞ 0.05。

Fig. 2 Seasonal changes of chlorophyll content (Chl) of Quercus wutaishanica (A) and Acer pictum subsp. mono (B) in response to nitrogen treatment (mean ± SD). **, p ＜ 0.01; *, p ＜ 0.05; ns, p ＞ 0.05.

图3 氮处理对辽东栎(A-C)和五角枫(D-F)叶绿素荧光性状光系统II最大光化学效率(PHI(Po))、电子受体库大小(Sm)和初级醌受体被还原周转次数(N)的季节性影响(平均值±标准偏差)。**, p ＜ 0.01; *, p ＜ 0.05; ns, p ＞ 0.05。由于仪器出现故障7月份数据缺失。

Fig. 3 Seasonal changes of maximal PSII efficiency (PHI(Po)), size of QA pool (Sm) and the QA reduced turnover number (N) of Quercus wutaishanica (A-C) and Acer pictum subsp. mono (D-F) in response to nitrogen treatment (mean ± SD). **, p ＜ 0.01; *, p ＜ 0.05; ns, p ＞ 0.05. Data measured in July were missed due to instrument disorder.

图4 氮处理、树种及其交互作用对两个树种光合氮利用效率(PNUE)(A), 当年生枝条长度(B), 枝条生物量(C)的影响及氮处理对辽东栎种子单粒质量(D)的影响(平均值±标准偏差)。不同小写字母表示差异显著(p ＜ 0.05)。

Fig. 4 Effects of nitrogen addition, tree species and their interaction on photosynthetic nitrogen efficiency (PNUE)(A), length (B) and biomass (C) of the current-year branch of the two tree species, and effect of nitrogen addition on single seed mass (D) of Quercus wutaishanica (mean ± SD). Different lowercase letters indicate significant difference (p ＜ 0.05).

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