川西北几种常绿阔叶林土壤碳库和养分库的比较

Study on Soil Carbon and Nutrients Pools of Several Evergreen Broad-Leaved Forest Types in Northwest Sichuan

通过对原始青冈栎+栲树+薯豆成熟常绿阔叶林、次生润楠+桤木+楠木成熟常绿阔叶林和次生绿叶石栎+光皮桦+细齿柃木幼年常绿阔叶林3种四川西北部典型常绿阔叶林下土壤碳库、全量养分库的调查和分析,揭示了该区域常绿阔叶林顶级群落下土壤碳库和养分库的整体情况及变异规律。结果表明:源于林分起源、成熟阶段和树种特性不同,3种天然林分土壤碳库差异较大。3种林分土壤碳库分别为160.35 t/hm2,138.96 t/hm2,62.14 t/hm2,平均为120.48 t/hm2。不同养分库在3种林分间表现的规律性不同,但它们都受到林分类型及特征的重要影响。有机碳和各养分的存贮随土壤深度增加均呈减小的趋势,有机碳和总氮表现尤其明显。

To understand soil carbon and nutrient pool and variation patterns under evergreen broad-leaved forest in northwest Sichuan,we chose mature forest of Cyclobalanopsis glauca＋Castanopsis fargesii＋Elaeocarpus japonicus,secondary and mature forest of Machillus pingii＋Alnus cremastogyne＋Phoeba bournei,secondary and young forest of Lithocarpus hancei＋ Betula luminifera ＋Eurya nitida to represent the typical evergreen broad-leaved forest types of this area.After examining soil carbon and nutrients pools,we obtained the following results and conclusions： By reasons of the differences of forest origin and ripening stage and the characteristics of plants,there was a big difference among soil carbon pools of this three inartificial forest types.Their soil carbon pools were 160.35 t/hm^2,138.96 t/hm^2,62.14 t/hm^2 respectively and the mean was 120.48 t/hm^2.The soil nutrients pools had different representations among the three forest types;However all of them were significantly impacted by forest types and their characters.There were trends of soil carbon and nutrients decreased with soil depth.The soil carbon and total nitrogen had evident representation.