Impacts of land use change on soil organic matter chemistry in the Everglades, Florida - a characterization with pyrolysis-gas chromatography mass spectrometry
Impacts of land use change on soil organic matter chemistry in the Everglades, Florida - a characterization with pyrolysis-gas chromatography mass spectrometry
复制标题
佛罗里达州大沼泽地土地利用变化对土壤有机质化学的影响 - 使用热解-气相色谱-质谱法进行表征
DOI：
10.1016/j.geoderma.2018.12.041
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发表时间：
2019
期刊：
影响因子：
6.1
通讯作者：
Wright Alan
中科院分区：
文献类型：
--
作者：
Zhang Zhongsheng;Wang Jian Jim;Lyu Xianguo;Jiang Ming;Bhadha Jehangir;Wright Alan
将沼泽地开垦为农业用地的做法十分普遍。佛罗里达的大沼泽地农业区是大规模土地使用转变的一个明显例子，那里的淡水湿地被转变为甘蔗生产。这种土地利用的变化可以显着影响土壤有机质循环和过程。这种土地利用变化对土壤有机碳分子特征的影响尚不清楚。在这项研究中，三个表层土壤芯（0-5厘米，5-10厘米，和10-19厘米）从一个代表性的沼泽和甘蔗田在佛罗里达沼泽地与已知的土地利用历史和管理措施，采用热解-气相色谱-质谱（Py-GC/MS）的特征，以调查土壤有机质的分子特征。甘蔗地土壤有机碳、全氮、全硫和水溶性有机碳含量分别为37.02%、2.44%、0.46%和0.11%，甘蔗地土壤有机碳、全氮、全硫和水溶性有机碳含量分别为44.57%、2.62%、0.73%和0.38%。从总体上看，开垦沼泽地对甘蔗的增香作用明显（从11.37%到13.20%），多环芳烃（从0%到1.63%），正烷烃（从8.90%到16.17%），正烯烃（从25.10%到28.77%），其他产品（从7.33%到11.77%）和脂肪酸（从1.93%到3.87%），而这种变化减少了木质素的含量酚类化合物（23.33%~ 16.13%）、多糖（2.40%~ 1.03%）、苯并呋喃（1.67%~ 0.27%）和含氮化合物（5.07%~ 4.67%）。总体而言，沼泽地转化为甘蔗地利用不仅减少了总的SOC含量，但也改变了有机质的分子特征，脂肪族馏分的显着增加，几乎完全耗尽的木质素馏分，标志着SOC的动态变化，由于在沼泽地的土地变化。
Reclamation of marshlands for agricultural land use is widespread. An example of large-scale land use shifts is evident in the Everglades Agricultural Area of Florida where freshwater wetlands were converted to sugarcane (Saccharum officinarum) production. Such land-use shifts can markedly influence soil organic matter cycling and processes. The effect of such land use change on molecular characteristics of soil organic carbon is unknown. In this study, three surface soils cores (0–5 cm, 5–10 cm, and 10–19 cm) from a representative marsh and a sugarcane field in the Florida Everglades with known land use history and management practices were characterized using pyrolysis-gas chromatography–mass spectrometry (Py-GC/MS) to investigate molecular characteristics of soil organic matter. Soil organic carbon (SOC), total nitrogen, total sulfur, and water extractable organic carbon contents in sugarcane soil were 37.02%, 2.44%, 0.46% and 0.11%, while they were 44.57%, 2.62%, 0.73% and 0.38%, respectively. On the whole, marshland reclamation to sugarcane caused increase of aromatics (from 11.37% to 13.20%), polyaromatic hydrocarbon (from 0% to 1.63%),n-alkanes (from 8.90% to 16.17%),n-alkenes (from 25.10% to 28.77%), other aliphatics (from 7.33% to 11.77%) and fatty acids (from 1.93% to 3.87%) in pyrolysis products of soil organic matter (SOM), whereas this shift reduced lignin (from 12.87% to 2.47%), phenols (from 23.33% to 16.13%), polysaccharides (from 2.40% to 1.03%), benzofuran (from 1.67% to 0.27) and nitrogen containing compounds (from 5.07% to 4.67%), respectively. Overall, the conversion of marsh to sugarcane land use not only reduced total SOC contents but also altered molecular features of SOM with significant increases in aliphatic fractions and almost complete exhaustion of lignin fractions, signifying SOC dynamic shift due to land change in the Everglades.