Aims Litter fall acts as a connection between plants and soil and is the key in nutrient and energy cycling of forest ecosystems. Northeast (NE) China possesses one of the largest forest carbon stocks in the country; however, large scale litter fall patterns along environmental gradients in this region remain unclear. Our objective was to determine the relationship between litter production and climate indices, forest type and community structure for this region.
Methods Using data from 27 plots across NE China (recorded between 2004 and 2006 in Mt. Changbai, Mt. Mao’er, Liangshui and Genhe), we measured the litter fall for all major forest types in the region and statistically analyzed relationships between litter production and environmental factors.
Important findings Annual litter fall production averaged 2 337, 2 472, 3 130 and 4 146 kg8226;hm–2 for deciduous needleleaf forest, evergreen needleleaf forest, deciduous broadleaf forest and deciduous broadleaf and needleleaf mixed forest, respectively. Forest types differed greatly in composition of litter components. Mean proportions of leaf, branch and fruit for all forest types were 71%, 22% and 6%, respectively. Annual litter fall production was positively related to mean annual temperature (MAT; r=0.75, p<0.001), but was not significantly related to mean annual precipitation (MAP), forest type or community structure (p>0.05). Different litter fall components were controlled by different factors. Production of leaf litter was influenced by both MAT and forest type, and broadleaf forests showed a significantly higher leaf litter production than needleleaf forests with a similar climate. Branch litter production was mainly controlled by MAP and stand volume, while fruit litter production was affected by both forest type and MAP. Percentages of different litter components were mainly associated with MAP. Percentage of leaf litter was negatively correlated with MAP (r = –0.75, p<0.001), while percentage of branch litter showed a reverse pattern (r=0.68, p<0.001).