Aspect differences in above- and belowground carbon allocation: a Montana case-study

摘要

Aboveground net primary production (ANPP) and belowground gross primary production (BGPP) of all vegetation were mea- sured in eight young, paired plots on a north and south aspect in western Montana. Stands of high and low overstory tree leaf area index (LAI) were compared. BGPP increased with ANPP, though they were not directly proportional. ANPP ranged from 1550 to 4400 kg C ha~-1 year~-1 and BGPP ranged from 1360 to 3500 kg C ha~-1 year~-1. ANPP and BGPP were both significantly related to LAI and aspect, where both were greater on the north aspect at any given LAI. Litterfall represented the largest share of ANPP; increases in overstory biomass represented the next largest share. Soil CO_2 flux was higher on the north aspect.