我国森林地表凋落物现存量及养分特征

归纳总结了我国森林地表凋落物现存量、养分含量及贮量的变化规律,以及凋落物现存量的研究方法。结果表明:我国对地表凋落物的研究主要集中在亚热带,基本上涵盖了亚热带的各种林型,而热带和温带研究相对较少。从热带到亚热带和温带,随着纬度的增高,凋落物现存量增加,其平均值分别为4.62,28.44和68.90t.hm-2;L层所占比例逐渐增大,F和H层比例逐渐减小。此外,海拔、林型、林龄、群落演替及采伐强度等均影响凋落物现存量。地表凋落物的元素含量以有机C最高,其次为N或Ca,再其次是K和Mg,P含量最低。养分贮量具有明显的纬度地带性,即从热带、亚热带到温带,养分贮量逐渐增大,其范围大致是热带在68.7～147.9kg.hm-2之间,平均为117.6kg.hm-2;亚热带在15.1～1 504.4kg.hm-2之间,平均为199.5kg.hm-2;温带在367.2～1 499.4kg.hm-2之间,平均为767.7kg.hm-2。

Standing Crop and Nutrient Characteristics of Forest Floor Litter in China

The variation of litter standing crop,nutrient contents and the methods of examining storage of forest floor litter in China were summarized.Researches of forest littere were mainly concentrated on subtropical forests,covering various forest types,in these regions,little was found on tropical and temperate forests.Litter standing crop increased with the increase of the latitude,and the average values in tropical,subtropical and temperate forest were 4.62 t·hm-2,28.44 t·hm-2 and 68.90 t·hm-2,respectively,and the proportion of L layer increased,F and H layer gradually reduced from tropical to subtropical and temperate forests.In addition,litter standing crop was also influenced by elevation,forest types,forest age,vegetation succession and cutting intensity etc.The order of nutrient contents were the following,organic carbon > nitrogen or calcium > calium or magnesium > phosphorus.Nutrient storage had obvious features in latitudinal zone,increasing gradually from tropical forests to temperate forests.The scopes of nutrient storage were from 68.7 to 147.9 kg·hm-2,with an average value of 117.16 kg·hm-2 in tropical forests,from 15.1 to 1 504.4 kg·hm-2 with an average value of 199.5 kg·hm-2 in subtropical forests,from 367.2 to 1 499.4 kg·hm-2with an average value of 767.7 kg·hm-2 in temperate forests.