土壤质量特征的比较及聚类分析——以生态修复中的茂名油页岩废渣场土壤为例

Comparison of Soil quality characteristics and cluster analysis——Taking the ecological restoration of Maoming oil shale waste soil as an example

通过对广东茂名油页岩南北排土场的裸地、植林5年、植林16年和天然恢复20年的草地共5块试验地的土壤理化性质、微生物性状及土壤酶活性、凋落物厚度等影响土壤质量的各项因素的化验测试,再进行对比分析和聚类分析,结果表明:当λ=10时,可分为2类,南排土场的3块样地为1类,北排土场的2块样地为1类;当λ=8.8时,可分为3类,南排土场的3块样地为1类,北排土场的2块样地各为1类;当λ=5时,可分为4类,南排土场的大叶相思林地和天然恢复草地2块样地为1类,南排土场的桉树林地为1类,北排土场的2块样地各为1类.可见各类样地土壤特征非常明显,北排裸地土壤干旱,养分贫瘠,为强酸土;北排的林地植林5年的土壤与裸地相差不大,生态修复效果不明显;南排土场天然恢复20年的草地和植林16年的相思林、桉树林,其土壤微生物总数比裸地提高了约20倍,脲酶、磷酸酶、蔗糖酶活性以及土壤呼吸速率都明显增强,土壤理化性质也有所改善;研究中发现,大叶相思树对土壤改良效果要比桉树好;同时也认识到废渣场生态修复是一个非常缓慢的过程,要迅速控制污染,改善环境,必须辅以人工措施,以加速生态修复的进程.

Through the north and south Guangdong Maoming oil shale dump vegetation,reforestation,afforestation 5 years 16 years 20 years and natural restoration of grassland were 5 test to the physicochemical properties of soil,plant and animal,microorganism and enzyme activity in soil,litter thickness effects on soil quality of various factors of laboratory testing,and then contrast analysis and cluster analysis,the results show that: at the time,it can be divided into two categories:South dump three plots for a class and North dump two plots as a class;at the time,it can be divided into three categories:South dump three plots for a class,North dump two plots for each class;at the time,it can be divided into four categories: South dump of Acacia woodland and grassland natural recovery two plots for a class,South dump of Eucalyptus forest land is a type of,and North dump two plots for each class.And various types of sample characteristics are also very obvious,north of bare soil drought,nutrient poor,strong acid soil;north forest afforestation 5 years soil and bare little difference,ecological restoration effect is not obvious;the South dump of natural recovery 20 year grassland and afforestation 16 years of Acacia,eucalyptus forest,the soil microorganism amount than the bare land was increased about 20 times,phosphatase,urease,invertase activity and soil respiration rate were significantly increased,soil physical and chemical properties are also improved;study found,Acacia on soil improvement effect than Eucalyptus;while recognizing the residue field ecological restoration is a very slow process,to control pollution,improve the environment,must be supplemented by artificial measures to accelerate the process,ecological restoration.