重庆武陵山区柏木幼、中龄林的碳、氮、磷、钾储量及其分配特征

The Resere of Carbon,Nitrogen,Phosphorus and Potassium and Their Distribution Features in Young and Middle-aged Cupressus funebris Forests in the Wuling Mountain Area of Chongqing

对重庆武陵山区柏木幼、中龄林的碳氮磷钾储量及其分配格局进行研究,结果表明柏木幼、中龄林之间各器官的碳、氮、磷、钾含量差异不显著,但它们均以叶的碳、氮、磷含量最高,树干的碳、氮含量最小。树干是柏木林乔木层物质储量的主要器官,与幼龄林相比,柏木中龄林树干的磷、钾储量明显较高,其余器官的物质储量差异则不显著,同样地,它们之间的枯落物层、土壤层的物质储量整体差异也不明显,但柏木中龄林各土层的物质储量均高于幼龄林。柏木幼龄林碳、氮、磷、钾储量分别为144.5997 t·hm^(-2)、7.0839 t·hm^(-2)、1.2261 t·hm^(-2)和46.5130 t·hm^(-2),中龄林则分别为160.5415 t·hm^(-2)、10.0162 t·hm^(-2)、3.0957 t·hm^(-2)和49.0526 t·hm^(-2),分配格局均为土壤层>乔木层>枯落物层;土壤层仍是柏木幼、中龄林积累物质的主要储存库(平均所占比例分别为87.23%、91.92%)。总体来看,武陵山区柏木中龄林物质储量功能强于幼龄林。

The reserve of carbon（C）,nitrogen（N）,phosphorus（P）and potassium（K）and their distribution features were studied in young and middle-aged Cupressus funebris forests in the Wuling Mountain Area of Chongqing.The results showed that the contents of C,N,P and K in organs were not significantly different between young and middle-aged C.funebris forests.The contents of C,N and P were the highest in leaves for both forests,C and N content was the smallest in trunks.The trunk was the main organ for the material storage of tree layer in C.funebris forests.Compared with young forests,P and K storages in middle-aged C.funebris forest were significantly higher,but the difference of material storage in other organs between them was not significant.Similarly,the difference of material storages in litter layer and soil layer between young forosts were not significant generally,but material storage in each soil layer of middle-aged C.funebris forests was higher than that of young forests.C,N,P and K storage in young forests were 144.5997 t·hm^-2 ,7.0839 t·hm^-2 ,1.2261 t·hm^-2 and 46.5130 t·hm^-2 ,and those in middle-aged forests were 160.5415 t·hm^-2 ,10.0162 t·hm^-2 ,3.0957 t·hm^-2 and 49.0526 t·hm^-2 respectively.The storage distribution paltern was as follows soil layer〉tree layer〉and litter layer in descending order.Soil layer was still the main reservoir for material storage in young and middle-aged C.funebris forests （the average proportion was 87.23% and 91.92% respectively）.In general, the material storage function of middle-aged C.funebris forests was stronger than that of young forests in the Wuling Mountain Area.