下表示意“甘肃省南部某山地土壤有机质含量（单位：g·kg^－1）的变化”。据此完成下面小题。                                                                                                                                                                                                                                                                            

坡向	有机质含量
	2420m处	2640m处	3580m处	4050m处
半阴坡	41	24		120
半阳坡	23		62
阴坡			181
阳坡		20		90