Rhizosphere effects on soil extracellular enzymatic activity and microbial abundance during the low-temperature dormant season in a northern hardwood forest
Rhizosphere effects on soil extracellular enzymatic activity and microbial abundance during the low-temperature dormant season in a northern hardwood forest
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DOI：
10.1016/j.rhisph.2021.100465
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发表时间：
2022-03-01
期刊：
影响因子：
3.7
通讯作者：
Tateno, Ryunosuke
中科院分区：
文献类型：
--
作者：
Nakayama, Masataka;Tateno, Ryunosuke
植物根通过影响微生物和酶活性来改变其周围土壤（根际）内的养分循环，包括氮 (N) 和磷 (P) 循环。最近的研究主要集中在低温季节植物对养分的吸收。这项研究旨在揭示日本北部阔叶林低温季节根际养分动态。为此，在日本北部阔叶林的休眠季节开始（11 月）、休眠季节结束（4 月和 5 月）和生长季节中期（8 月）测量了冠层树木、林下植被和非根际大块土壤的潜在细胞外酶活性、细菌、真菌和古菌丰度以及土壤化学性质。无论季节如何，根际土壤中真菌的丰度都是非根际土壤的1.1-1.7倍。根际参与Nand P循环的酶活性也分别比土体土壤高1.4至4.0和1.3至1.9倍。在休眠季节开始和结束时，根际可提取有机氮浓度分别比非根际土壤高1.5-2.0倍，但在有机氮生长季节中期没有观察到这种趋势。由于根际养分浓度是由细根吸收的养分和根引起的分解加速之间的平衡决定的，我们的结果表明，植物根在休眠季节会加速氮和磷的循环，尽管在这个季节植物吸收的养分量较低。
Plant roots alter nutrient cycling, including nitrogen (N) and phosphorus (P) cycling, within the soil surrounding them (rhizosphere) by affecting microbes and enzyme activities. Recent studies have focused on nutrient uptake by plants in low-temperature seasons. This study aimed to reveal the nutrient dynamics in the rhizosphere during low-temperature seasons in a northern hardwood forest in Japan. For this purpose, the potential extracellular enzymatic activity, bacterial, fungal, and archaeal abundances, and soil chemical properties in the rhizosphere of canopy trees and understory vegetation and non-rhizosphere bulk soil were measured at the beginning of the dormant season (November), end of the dormant season (April and May), and middle of the growing season (August) in a northern hardwood forest in Japan. The abundance of fungi was 1.1-1.7 times higher in the rhizosphere than in non-rhizosphere bulk soil regardless of the season. The activity of enzymes involved in Nand P-cycles in the rhizospheres was also 1.4 to 4.0 and 1.3 to 1.9 times higher than that in bulk soil, respectively. The concentration of extractable organic N was 1.5-2.0 times higher in the rhizosphere than in the non-rhizosphere bulk soil at the beginning and end of the dormant season, respectively, but this trend was not observed in the middle of the growing season for organic N. Since the concentration of nutrients in the rhizosphere is determined by the balance between nutrient uptake by fine roots and root-induced acceleration of decomposition, our results suggest that plant roots would accelerate N and P cycles during the dormant season, even though the amount of nutrient uptake by plants was lower during the season.