胡桃楸、落叶松纯林及其混交林下叶凋落物分解与养分归还的比较研究

用分解袋法研究了胡桃楸、落叶松纯林及其混交林下叶凋落物的分解及养分归还速率,结果表明3种林分叶凋落物分解速率大小为胡桃楸纯林>混交林>落叶松纯林。如排除微生物侵入等的影响,胡桃楸纯林叶凋落物归还N的速率最快,落叶松纯林叶凋落物归还P、K的速率最快;二者组成混交林后,混交林叶凋落物归还N的速率较落叶松纯林明显提高,而归还P、K的速率较胡桃楸纯林明显提高。胡桃楸与落叶松混交后叶凋落物养分归还速率较其各自纯林的要高,这可能是混交林增产机制之一。

Study on the Decomposition and Nutrient Return of the Leaf Litter under the Pure and Mixed Plantations of Juglans mandshrica and Larix gmelinii

The characteristics of the decomposition and the nutrient return of the leaf litters under the pure and mixed plantations of Juglans mandshurica and Larix gmelinii were studied by decomposing-bag method.The result showed that the decomposing rates was as follows:the Juglans mandshurica pure plantation>mixed plantation>the Larix gmelinii pure plantation.If the invasion of the microbe was excluded,the return rate of the nitrogen element was the fastest in the pure plantation of Juglans mandshurica and on the other hand the return rates of the phosphorus and potassium were the fastest in the prue plantation of Larix gmelinii .The return rate of the nitrogen in the mixed plantation was obviously faster than it was in the Larix gmelinii pure plantation and those of the phosphorus and potassium were obviously faster than they were in the Juglans mandshurica prue plantation.In contrast with the pure plantations,the improvement of the retrun rates of the nutrient elements in the mixed plantation may be one of the machenisms for the growth improvement of the mixed plantation.