亚热带红壤丘陵区不同人工林型对土壤理化性质、微生物类群和酶活性的影响

摘要

The aim of this study was to explore effects of different artificial forestry on soil physio-chemical properties, microbial groups and enzyme activities in subtropical red soil hilly region. Taking four kinds of artificial forestry (C. camphora (CC), C. lanceolata (CL), C. lanceolata-C. camphora (CLCC) and Natural restoring (NR)) and barren grassland (CK) nearby as test objects, soil samples from depths of 0~10, 10~20 and 20~40 cm were collected to study the effects of four kinds of artificial forestry on soil physio-chemical properties, microbial groups and enzyme activities through the combination of sample investigation and experimental analysis. The results showed that:(1) Compared with barren grassland (CK), the total number of microbes in different artificial forestry were followed the order as CLCC>CC>CL>NR>CK (P<0.05). (2) The activities of soil urease (URE) in different artificial forestry were followed the order as CC>CLCC>CL>NR>CK (P<0.05);Invertase (INV), CC>NR>CLCC>CK>CL (P<0.05), Acidity phosphatase (APE), CC and CLCC>NR>CL>CK (P<0.05). (3) In the profile, soil microbial groups and enzyme activities decrease with the increase of soil depth. 4)Correlation analysis showed that the contents of bacteria and fungi have a significant or very significantly positive correlation with URE and APE (P<0.05 or P<0.01);the soil microbial groups and enzyme activities have a very significantly positive correlation with soil organic matter (SOM), total nitrogen (TN) and available nitrogen (AN) (P<0.01). All the results showed that returning farmland to forests (grass) could increase the number of soil microbial groups and the activities of soil enzyme, promoting the improvement of soil physical properties and the heighten of soil fertility.%为了探讨亚热带红壤丘陵区不同人工林对土壤理化性质、微生物类群和酶活性的影响。以亚热带红壤丘陵区的纯樟树林（CC）、纯杉木林（CL）、杉木樟树混交林（CLCC）、自然恢复地（受到人为干扰）（NR）作为研究对象，并以附近的疏草荒地（GD）作为对照（CK），通过调查取样和实验分析相结合的方法，分析不同人工林型中不同土层（0~10、10~20和20~40 cm）土壤的理化性质、微生物类群和酶活性的变化。结果表明，（1）与对照相比，不同林型下土壤细菌、真菌和放线菌总数均显著增加，依次为微生物总数（CLCC）>微生物总数（CC）>微生物总数（CL）>微生物总数（NR）>微生物总数（CK）（P<0.05）。（2）土壤脲酶（URE）活性在不同林型下的大小顺序为脲酶（CC）>脲酶（CLCC）>脲酶（CL）>脲酶（NR）>脲酶（CK）（P<0.05）；蔗糖酶（INV）活性的大小顺序为蔗糖酶（CC）>蔗糖酶（NR）>蔗糖酶（CLCC）>蔗糖酶（CK）>蔗糖酶（CL）(P<0.05）；酸性磷酸酶（APE）活性的大小顺序为酸性磷酸酶（CC和CLCC）>酸性磷酸酶（NR）>酸性磷酸酶（CL）>酸性磷酸酶（CK）（P<0.05）。（3）在剖面层次上，土壤微生物类群和酶活性也有明显的层次性，即随着土层的增加而减小。（4）相关分析表明：土壤细菌、真菌与脲酶、酸性磷酸酶之间具有显著或极显著的相关性（P<0.05或P<0.01）；土壤微生物类群和酶活性与土壤有机质（SOM）、全氮（TN）和有效氮（AN）之间具有极显著的相关性（P<0.01）。研究结果表明退耕还林（草）可增加土壤微生物类群的数量和土壤酶活性，促进土壤物理性状的改善和肥力的提高。