日本中部风景林凋落物量、养分归还量

研究了日本中部的3个风景林－常绿针叶林、常绿阔叶林和常绿落叶阔叶混交林的凋落物，养分归还量和养分利用效率。常绿针叶林、常绿阔叶林和常绿落叶阔叶混交林的年凋落量分别为7562、6023和5565kg/hm^2，养分年归还量分别为233．87、125．20t 140.23kg/hm^2，各养分中N、K和Ca的归还量大于P和Mg叶的养分归还量占养分年归还量的64．19％－79．29％。常绿针叶林和常绿阔叶林中 Mg的利用效率高，表明Mg可能是这2种风景林生长的限制因子。

Study on Litterfall, Nutrient Returned by Litterfall and Nutrient Use Efficiency in Scenic Forests of Central Japan

Litterfall amounts, nutrients returned by litterfall and nutrientuse efficiency in evergreen coniferous forest, evergreen broad-leaved forest, and evergreen and deciduous broad-leaved mixed forest of Central Japan were studied. Annual amounts of litterfall in evergreen coniferous forest, evergreen broad-leaved forest, and mixed forest were 7 562， 6 023 and 5 565 kg/hm2, respectively, which resulted in the amount of nutrient contained in litterfall being 233.87, 125.20 and 140.23 kg/hm2, respectively. Returned amounts of N, K and Ca were greater than P and Mg in all scenic forests, and leaves contributed 64.19%～79.29% of the total. A high Mg use efficiency in evergreen coniferous forest and evergreen broad-leaved forest indicates that Mg may be in a limited supply in the two scenic forests.