Responses in gross primary production of Stipa krylovii and Allium polyrhizum to a temporal rainfall in a temperate grassland of Inner Mongolia, China
Responses in gross primary production of Stipa krylovii and Allium polyrhizum to a temporal rainfall in a temperate grassland of Inner Mongolia, China
复制标题
内蒙古温带草原克氏针茅和葱的初级生产力对暂时性降雨的响应
DOI：
10.1007/s40333-019-0127-1
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发表时间：
2019-11-12
影响因子：
3
通讯作者：
Kamijo, Takashi
中科院分区：
文献类型：
--
作者：
Hu, Xiaoxing;Hirota, Mitsuru;Kamijo, Takashi
在中国干旱半干旱地区，降雨和干旱会影响植物的生长和光合作用活动。总初级生产力是衡量植物光合作用能力的重要指标之一。本文以克氏针茅(Stipa Krylovii)和多根葱(Allium PolyRhum)两种典型草地植物的GPP为研究对象，研究了时间降雨对这两种植物的影响。本研究是在内蒙古自治区中国自治区呼伦贝尔市新巴拉格右旗温带草原进行的，时间是2015年的一个干旱年。我们利用透明小室系统测量了净生态系统生产力(NEP)和生态系统呼吸通量(ER)，并同时监测了光合作用有效辐射(PAR)、空气和土壤温度和湿度。基于NEP和ER的实测值，我们计算了降雨前后两种植物的GPP。在35℃以下的低温条件下，9.1 mm降雨后第1天和第2天，克氏针茅的单位地上饱和生物量(GPPAGB)由0.033(±0.018)增至0.185(±0.055)µmolCO_2/(gdw·S)，较降雨前显著增加5.6倍；克氏针茅由0.068(±0.021)降至0.034(±0.011)µmolCO_2(gdw·S)，较降雨前增加0.5倍。在35℃以上的高温下，克氏针茅和多根沙打旺的饱和GPPAGB值(分别为0.018(±0.007)和0.110(±0.061)µmolCO2/(gdw·S))均显著低于35℃以下的低温下(0.034(±0.011)和0.185(±0.055)µmolCO2/(gdw·S))。结果表明，克氏针茅和多根沙打旺的GPP对时间降雨的响应不同，受温度的影响较大。时间降雨量对多根草GPP的影响似乎比克氏针茅更大。这些差异可能与不同的生理和结构特征、物种的共存及其物种特有的生存策略有关。
In the arid and semi-arid areas of China, rainfall and drought affect the growth and photosynthetic activities of plants. Gross primary productivity (GPP) is one of the most important indices that measure the photosynthetic ability of plants. This paper focused on the GPP of two representative grassland species (Stipa krylovii and Allium polyrhizum) to demonstrate the effect of a temporal rainfall on the two species. Our research was conducted in a temperate grassland in New Barag Right Banner, Hulun Buir City, Inner Mongolia Autonomous Region of China, in a dry year 2015. We measured net ecosystem productivity (NEP) and ecosystem respiration flux (ER) using a transparent chamber system and monitored the photosynthetically active radiation (PAR), air and soil temperature and humidity simultaneously. Based on the measured values of NEP and ER, we calculated the GPP of the two species before and after the rainfall. The saturated GPP per aboveground biomass (GPPAGB) of A. polyrhizum remarkably increased from 0.033 (±0.018) to 0.185 (±0.055) µmol CO2/(gdw·s) by 5.6-fold and that of S. krylovii decreased from 0.068 (±0.021) to 0.034 (±0.011) µmol CO2(gdw·s) by 0.5-fold on the 1st and 2nd d after a 9.1 mm rainfall event compared to the values before the rainfall at low temperatures below 35°C. However, on the 1st and 2nd d after the rainfall, both of the saturated GPPAGB values of S. krylovii and A. polyrhizum were significantly lower at high temperatures above 35°C (0.018 (±0.007) and 0.110 (±0.061) µmol CO2/(gdw·s), respectively) than at low temperatures below 35°C (0.034 (±0.011) and 0.185 (±0.055) µmol CO2/(gdw·s), respectively). The results showed that the GPP responses to the temporal rainfall differed between S. krylovii and A. polyrhizum and strongly negative influenced by temperature. The temporal rainfall seems to be more effective on the GPP of A. polyrhizum than S. krylovii. These differences might be related to the different physiological and structural features, the coexistence of the species and their species-specific survival strategies.