Changes in soil phosphorus and its influencing factors following afforestation in Northern China

Abstract

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.

Soil phosphorus determines the distinct assembly strategies for abundant and rare bacterial communities during successional reforestation

“…Interestingly, soil total phosphorus mediated the balance between stochastic and deterministic assembly processes for the abundant and rare bacteria, while the community assembly of abundant and rare bacteria had distinct response strategies to total phosphorus during successional reforestation. As a major nutritional constraint for primary production in terrestrial ecosystems (Cleveland et al, 2013), soil phosphorus content cannot be quickly replenished as it is primarily obtained from rock weathering (Walker and Adams, 1958;Li et al, 2019). And this further affects the dynamics of soil C stocks (Shi et al, 2016) and nitrogen cycling (Vitousek et al, 2010).…”

“…And this further affects the dynamics of soil C stocks (Shi et al, 2016) and nitrogen cycling (Vitousek et al, 2010). In addition, soil P concentration in the Loess Plateau is lower on average than the global mean, which exacerbate soil P as the main limiting factor (Li et al, 2019). Previous research has shown that soil phosphorus significantly influenced the structure and diversity of the soil microbial community in Loess Plateau ecosystems (Jangid et al, 2013;Chen et al, 2014;Li et al, 2019;Randall et al, 2019).…”

“…In addition, soil P concentration in the Loess Plateau is lower on average than the global mean, which exacerbate soil P as the main limiting factor (Li et al, 2019). Previous research has shown that soil phosphorus significantly influenced the structure and diversity of the soil microbial community in Loess Plateau ecosystems (Jangid et al, 2013;Chen et al, 2014;Li et al, 2019;Randall et al, 2019). Moreover, since our samples are collected around the twodimensional space (vertical and horizontal) of the soil profile of a single tree, the role of soil phosphorus in regulating community assembly of the abundant and rare bacteria may be amplified by the rhizosphere effect of plants because phosphorus is the main nutrient of plants.…”

Global patterns and drivers of soil total phosphorus concentration

“…Each of these factors may be characterized by a few variables; for example, climate may be characterized by mean annual temperature (MAT) and precipitation (MAP). Relationships between soil total P concentration and variables such as parent material type and P concentration, MAT, MAP, site slope, and soil organic carbon (SOC) have been reported in previous studies but mostly at local to regional scales (Brédoire et al, 2016;Cheng et al, 2018;Li et al, 2019;Porder and Chadwick, 2009;Wang et al, 2009). Few studies have quantified the relative importance of these variables for predicting soil total P concentration at a global scale (Delgado-Baquerizo et al, 2020;Augusto et al, 2017;Yang et al, 2013).…”

Spatial Distribution and Regulating Factors of Soil Nutrient Stocks in Afforested Dump of Pingshuo Opencast Coalmine, China

“…Li et al [19] found that the contents of SOC, TN, AN, and AK in woodland were much higher than those in grassland, shrubland, and cropland, but land-use types did not significantly affect other soil nutrient contents (e.g., TP and TK); they also drew the conclusion that climate factors, soil texture, and pH induced the variations of soil nutrient contents. The conclusions of regional-scale studies might contrast with each other due to the difference in climate, geological background, and soil conditions [20], which highlights the significance of regional studies into different ecosystems. Different from natural soils, reclaimed soils are much more heterogeneous and compact due to the irregular mixing of different materials (e.g., plant residues, fly ash, and soil particles) and the compaction of it by heavy machinery [21,22].…”