Vegetations in the natural reserve had evident carbon sink functions, mainly exhibiting in the increasing of carbon, about 1.058×10 6t·a -1 . The annual carbon of mixed broad-leaved and Korean pine forest increased greatest (0.452×10 6t·a -1 ), secondly spruce-fir forest (0.339×10 6t·a -1 ).
The difference between highest and lowest monthly mean values is about 72% in Broad-leaved Korean Pine forest,73% in Asian white birch forest,26% in David poplar forest,56% in Spruce-fir forest,and 144% in Ermans Birch forest.
Based on a systematic summing-up of stand growth modeling and on an analysis of present research situation of ecological cutting/regeneration, the paper carried through analysis and modeling of growth dynamic of studied objects, and investigated the impact of logging activity on the objects and environment, thus proposing a technical system for logging regeneration in larch and spruce-fir forest environment on Changbai Mountains, including both common technical principles and individual technical indexes.
Result showed that flammable fuel types are spruce-fir forest with 80 or 103-year-old Picea jezoenszs and 115-year-old Larix olgensis forest, and uninflammable fuel types are 115 or 142-year-old Betula ermanii forest and 87-year-old B. platyphylla forest.
Over 72.9% of fine roots are distributed within 0～10 cm of soil surface,which varies slightly among different communities. The fine root biomass in top 10 cm of forest soil surface follows the sequence of Asian white birch forest,Broad-leaved Korean Pine forest, Spruce-fir forest,Ermans Birch forest and David poplar forest from high to low.
The total NPP was estimated to be 1.332×10 6 t C·yr -1 . The highest total NPP appeared in mixed broad leaved and Korean pine forests and spruce fir forest, which were 0.540×10 6 t C·yr. -1 and 0.428×10 6 t C·yr.
(b)Based on important value of the main companion species,the spruce fir forests on the northern slope of Changbai Mts. are classified into three categories,the Korean pine Spruce fir Forest(Alt.1290m),the Typical Spruce fir Forest(Alt.1500m)and Ermans birch Spruce fir Forest(Alt.1680～1820m).
Based on a two-dimensional non-rank classification of two way indicativespecies analysis(TWINSPAN),spruce and fir forest communities in Northwest Sichuan and South Gansu are divided into 15 associations belonging to4 formations by using the DCA and TWINSPAN classification methods.
The results indicated that according to ecological techniques, operations could reduce impact on environment, maintain the productivity of spruce-fir forests for a long time, consequently meet many requirements of environmental protection, economic output and social benefit and accelerate sustainable forest mangement at operation level finally.
The paper combined research results with mature operation techniques, referred to international and national regulations ,and then proposed ecological logging and regeneration techniques and relevant requirements suitable for spruce-fir forests in Changbai Mountain.
Carbon and nitrogen isotope ratios in different compartments of a healthy and a declining Picea abies forest in the Fichtelgebir
Regeneration in experimental gaps of subalpine Picea abies forest in the Slovenian Alps
Spatial distribution of Collybia pinastris sporophores in a Picea abies forest floor over a 5-year period
Four phases of catchment vegetation type were defined based on plant macrofossil analyses: open Betula-Pinus cembra woodland, Abies alba-Pinus cembra woodland, Picea abies forest, and cultural pasture.
Response of fine roots to an experimental gap in a boreal Picea abies forest