ObjectiveThe temporal and spatial change patterns and its formation mechanism on soil available phosphorus were analyzed in the Larix gmelinii forests, which was disturbed by 3 kinds of intensity fire, to understand soil available phosphorus habitat and to provide reference to mineral nutrition regulation in the early vegetation restoration after forest fire.

MethodTaking soil available phosphorus as research object, latticed co-coupled sampling method, soil-drilling method, and H₂SO₄-HCl extraction method were conducted to investigate temporal and spatial variations of soil available phosphorus under an autumn experimental forest fire in the boreal Larix gmelinii forests of Great Xing'an Mountain of northeastern China.

ResultAfter forest fire disturbance: (1) soil available phosphorus of mild burned area was not changed immediately and then increased, that of moderate burned area or severe burned area increased immediately and then increased continually; (2) significant correlation of spatial pattern was between soil available phosphorus and fire intensity at each post-fire time node, correlation of spatial pattern between soil available phosphorus change and fire intensity appeared immediately after the fire, but that disappeared after snowmelt season and rainy season/growing season.

ConclusionIn the early years of post-fire forest transformation or ecological restoration, increased soil available phosphorus is advantageous to the forest vegetation restoration of Larix gmelinii forests in Great Xing'an Mountain of northeastern China.