中国科学院水利部水土保持研究所机构知识库

Changes in soil carbon (C) and nitrogen (N) stocks following afforestation have been
widely studied at different scales. However, soil phosphorus (P) dynamics following
afforestation are poorly understood, especially at the regional scale. This paper
studied the effects of prior land use (cropland, grassland, and barren land), tree
species (conifer, broadleaf, shrub, and mixed), plantation age (young, middle, and
old), and climate on soil total phosphorus and available phosphorus stocks change
in the top 20 cm following afforestation based on a synthesis of 50 recent publications
in northern China. We also considered possible confounding effects between
these factors. The results showed that, overall, soil total phosphorus and available
phosphorus stocks significantly decreased by 7.3% and significantly increased by
8.8%, respectively, following afforestation. Prior land use was found to be the most
important driver in determining changes in soil P stocks. Compared with a significant
decrease in P of afforestation of former cropland and grassland, afforestation of barren
land caused no clear decrease in P. Tree species was found to have a limited
effect on changes in soil P after afforestation, and broadleaf afforestation has a lower
P demand than coniferous forests in the studied region. Plantation age did not affect
the dynamics of P stocks. Our results showed confounding effects of precipitation,
prior land use, and tree species, which impacted the estimates of the drivers of
changes in P stocks. These results highlighted the importance of tree species
selection and replication across sites that receive different amounts of precipitation.