The recovery of ecosystem processes after wildfire in Michigan jack pine forests (Michigan).

摘要

I investigated the recovery of ecosystem processes after wildfire in Michigan jack pine (Pinus banksiana) forests using a chronosequence of 11 wildfire-regenerated stands spanning 72 years. The objective of this study was to characterize recovery patterns of soil nutrients, soil carbon (C) and nitrogen (N) mineralization, as well as determine the mechanisms that drive those patterns.; Total N mineralization spiked immediately following wildfire, decreased to minimum values after about 10--15 years following wildfire, and then increased, reaching a steady state after about 40 years. Soil respiration rates declined immediately after wildfire, increased after about 10--15 years, followed by a decreasing trend after 30 years.; In Michigan jack pine forests, accumulation of the forest floor largely regulates the recovery of N mineralization. The successional pattern of annual N mineralization was driven by rapid turnover of N in the mineral soil immediately following wildfire, followed by a gradual accrual of a slow-cycling pool of N in forest floor as stands matured. Soil respiration was most likely driven by heterotrophic microbial respiration early in succession and later by both root respiration and microbial respiration. All measured ecosystem processes recovered to predisturbance levels within 40 years of wildfire.