Different life-form plants exert different rhizosphere effects on phosphorus biogeochemistry in subtropical mountainous soils with low and high phosphorus content
Different life-form plants exert different rhizosphere effects on phosphorus biogeochemistry in subtropical mountainous soils with low and high phosphorus content
复制标题
不同生命型植物对低磷和高磷亚热带山地土壤磷生物地球化学的根际影响不同
DOI：
10.1016/j.still.2019.104516
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发表时间：
2020-05-01
影响因子：
6.5
通讯作者：
Li, Bo
中科院分区：
文献类型：
--
作者：
Fu, Denggao;Wu, Xiaoni;Li, Bo
土壤磷（P）是支撑陆地生态系统生产力和功能的最重要但了解最少的养分之一。要了解土壤磷循环，必须量化植物对土壤磷组分（活性无机磷[Pi]、中等有效性Pi、有机磷和闭蓄态磷）的影响。本研究旨在比较中国西南亚热带山区不同生活型植物的根际效应如何影响缺磷和富磷土壤中的磷组分。对于所选的三个物种（本土针叶树云南松；本土灌木铁仔；入侵草本植物紫茎泽兰），高磷位点的总磷和磷组分浓度远高于低磷位点。在低磷位点，闭蓄态磷和有机磷是主要组分，而在高磷位点，闭蓄态磷和中等有效性磷是主要磷组分。物种特性显著影响两个位点的所有五种土壤磷组分，但高磷位点的有机磷除外。总磷、活性磷和中等有效性磷随时间显著变化。此外，植物能够增强低磷位点对活性磷和中等有效性磷以及高磷位点对有机磷的根际效应。紫茎泽兰对低磷位点的活性磷和中等有效性磷以及高磷位点的活性磷和有机磷产生了显著的正根际效应。因此，与本土的铁仔和云南松相比，入侵植物紫茎泽兰能够更有效地改变根际土壤磷组分以应对不同的土壤磷水平。线性回归表明，对活性磷的根际效应与对pH的根际效应相关，对有机磷的根际效应与对土壤有机质以及可交换铁氧化物和铝氧化物的根际效应有关。总之，不同生活型植物通常通过地球化学和生物过程产生不同的根际效应，从而影响不同土壤磷含量下的磷生物地球化学循环。
Soil phosphorus (P) is among the most important but least understood nutrients supporting the productivity and function of terrestrial ecosystems. To understand soil P cycling, it is essential to quantify the effects of plants on soil P fractions (labile inorganic P [Pi), intermediately available Pi, organic P, and occluded P). The study aimed to compare how the rhizosphere effect of different life-form plants influences P fractions in P-depleted and P. enriched soils in southwest China's subtropical mountainous region. For all three selected species (native conifer, Pinus yunnanensis; native shrub, Myrsine africana; invasive herb: Eupatoriurn adenophorum), total P and P-fraction concentrations were much higher in the high-P site than in the low-P site. Occluded and organic P were the dominant fractions at the low-P site, while occluded and intermediate P were the dominant P fractions at the high-P site. Species identity significantly affected all five soil P fractions in both sites, except organic P at the high-P site. Total P, labile P, and intermediate P changed significantly with time. Additionally, plants were able to increase the rhizosphere effect on labile and intermediate P at the low-P site, as well as organic P at the high-P site. Eupabarium adenophorum exerted a significantly positive rhizosphere effect on labile and intermediate P at the low-P site, as well on labile P and organic P in the high-P site. Thus, compared with native M. africana and P. yunnanensis, the invasive E. adenophorum can more effectively alter rhizosphere soil P fractions in response to different soil P levels. Linear regression showed that the rhizosphere effect on labile P was correlated with the rhizosphere effect on pH, and the rhizosphere effect on organic P was related to the rhizosphere effect on soil organic matter and exchangeable Fe-ox and Al-ox. In conclusion, different life-form plants generally exert a different rhizosphere effect through geochemical and biological processes, thus influencing P biogeochemical cycling in different soil P contents.