AUTHOR=Lin Zhenrong , Shi Lina , Wei Xiaoting , Han Bing , Peng Cuoji , Yao Zeying , Xiao Qing , Lu Xinmin , Deng Yanfang , Zhou Huakun , Liu Kesi , Shao Xinqing 

TITLE=Soil properties rather than plant diversity mediate the response of soil bacterial community to N and P additions in an alpine meadow

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1036451

DOI=10.3389/fmicb.2022.1036451

ISSN=1664-302X

ABSTRACT=<p>The alpine meadow on the Qinghai-Tibetan Plateau, which is susceptible to global climate change and human activities, is subject to nutrient addition such as nitrogen (N) and phosphorus (P) to enhance soil available nutrients and ecosystem productivity. Soil bacterial community partly drivers the effects of nutrient additions on ecosystem processes, whereas the factors influencing N and P additions on bacterial community in alpine meadows are not well documented. We conducted a N and P addition experiment in an alpine meadow ecosystem on the Qinghai-Tibetan Plateau with four treatments: untreated control (CK), N addition (N), P addition (P), and NP addition (NP). We employed a high-throughput Illumina Miseq sequencing technology to investigate the response of soil bacterial community to short-term N and P additions. N and P additions decreased soil bacterial richness (OTU numbers and Chao 1 index), and P addition decreased soil bacterial diversity (Shannon and Simpson indices). N addition directly induced the change of soil <inline-formula><mml:math id="M1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mtext>N</mml:mtext><mml:msubsup><mml:mtext>H</mml:mtext><mml:mn>4</mml:mn><mml:mo>+</mml:mo></mml:msubsup><mml:mo>−</mml:mo><mml:mtext>N</mml:mtext></mml:mrow></mml:math></inline-formula>, and decreased plant diversity. The N and P additions reduced soil bacterial community diversity, whose response was independent with plant diversity. Additionally, nutrient additions altered soil bacterial community composition, which were highly correlated with soil properties (i.e. pH, <inline-formula><mml:math id="M2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mtext>N</mml:mtext><mml:msubsup><mml:mtext>H</mml:mtext><mml:mn>4</mml:mn><mml:mo>+</mml:mo></mml:msubsup><mml:mo>−</mml:mo><mml:mtext>N</mml:mtext></mml:mrow></mml:math></inline-formula>, and TP) as shown by RDA. Consistently, structural equation modeling results revealed that N addition indirectly acted on soil bacterial community through altering soil available nutrients and pH, while P addition indirectly affected bacterial community by increasing soil P availability. These findings imply that more attention should be paid to soil properties in regulating belowground biodiversity process in alpine meadows under future environmental change scenario.</p>