两种落叶分解过程中养分和碳素的行为

利用分解袋法对日本亚高山针叶林的针叶(Abies veitchii Lindl,and A.mariesi Mast.)和阔叶(Betula ermanii Cham.and B.corylifolia Regal.et Maxim．)凋落物进行了分解实验研究。结果表明尽管分解初期的两种凋落物的养分以及分解后期凋落物剩余重量差异很大，但两种凋落物养分浓度在分解后期(30个月以后)趋于一致。这种趋同现象在不同养分中有不同的趋同机制。氮元素浓度升高到分解后期浓度差变小，这种现象是由于分解菌的固持作用及受木质素的束缚所致；钾和镁在分解初期浓度急剧下降，进而浓度差变小，是由于淋溶作用所致。在分解过程中这些元素非常容易被淋溶掉，直到和土壤中的浓度达到一致为止。钙是结构元素，它的行踪和有机物组分有密切关系。由于分解后期有机组分木质化和腐殖质化进而浓度趋同，所以钙的浓度也相应趋同。

Behavior of Carbon and Nutrients Within Two Types of Leaf LitterDuring 3.5-year Decomposition

A litter bag study of needle (Abies veitchii Lindl. and A. mariesi Mast.) and leaf litter (Betulaermanii Cham. and B. corylifolia Regal. et Maxim.) conducted in a coniferous forest of Mt. Ontake, Japanshowed the similar qualities of two type litters in later stages (after the 30th month). Although thedifference in remaining mass between the two litters was larger in later stage of decomposition and initialconcentration of nutrients was different. The concentrations of carbon (C) fraction and nutrients be-tween the two types of litter tended to similar in the later stages. The similar concentration trend ofnutrients was due to different mechanisms. Nitrogen (N) was due to immobilization of fungi and binding withlignin. K and Mg were leaching elements. They were very easily affected in leaching process. In the laterstage, they reached a similar concentration because of a balance with the soil concentration. Ca is aconstruction element, so its behavior has closely related to that of C fractions. Moreover, C fractionswere lignified or humuified and remained similar in later stage, Ca was also became similar in concentrationin the later stage.