Characteristics of Fine Root Morphology and Biomass Vertical Distribution from Different Provenances and Families of Picea koraiensis
In order to reveal the characteristics of fine root(diameter≤2 mm)morphology and vertical distribution of biomass from different provenances and families of 24-year-old Picea koraiensis,the soil core method was used to determine fine root morphology and biomass at different soil layers(surface layer:0<h≤10 cm,subsurface layer:10 cm<h≤20 cm,bottom layer:20 cm<h≤30 cm)in 30 families from four provenances(Muling,Linkou,Jinshantun,and Wuyiling from low to high latitude)in Qingshan Forest Farm,Linkou County,Heilongjiang Province,China.The results showed that there were significant differences in all fine root morphological traits among different provenances,and specific root length and root tissue density exhibited significant differences among families within provenance.At the provenance level,the average root diameter of Wuyiling provenance was the thickest at all soil layers,whereas specific root length and root tissue density of Linkou provenance were the largest.At the family level,in 0<h≤10 cm soil layer,root diameter of W035 was the thickest,that of CK-2 was the thinnest,specific root length of CK-2 was the longest,that of W043 was the shortest,root tissue density of J082 was the highest,that of M515 was the lowest.Root tissue density and specific root length of different provenances and families of P.koraiensis decreased with the increase of soil layer,while root diameter increased.The total fine root biomass(all three soil layers)across the four provenances was 33.56 g·m-2 on average,with the maximum occurring in Linkou provenance(39.04 g·m-2)and the minimum in Jinshantun provenance(32.52 g·m-2),showing inconsecutive geographical distribution.Fine root biomass decreased with soil layer increasing,and root biomass at the surface soil layer accounted for 77%of the total biomass on average.In comparison,the low-latitude provenance of Muling tended to distribute greater fine root biomass at the subsurface and bottom soil layers,while the high-latitude provenances of Wuyiling and Jinshantun had higher fine root biomass at the surface soil layer,indicating that P.koraiensis originated from cold site tended to allocate more fine roots at the fertile surface soil.