The Long-Term Effects of Barren Land Afforestation on Plant Productivity, Soil Fertility, and Soil Moisture in China: A Meta-Analysis.

As global ecological degradation intensifies, the long-term impacts of afforestation on productivity and soil fertility in barren lands have become critical in improving global ecological security and productivity. Through meta-analysis, this study integrates data from 109 barren land afforestation sites across China, aiming to comprehensively analyze the effects on plant productivity and soil fertility while identifying the key environmental drivers of these changes. We found that afforestation consistently enhances plant productivity across 60 years. However, soil fertility and moisture initially surged significantly after afforestation but gradually declined after the first decade, indicating the limited long-term benefits. Climatic factors, namely precipitation and humidity index, are crucial in enhancing plant productivity, while geographic factors, specifically lower elevations and gentler slopes, are associated with greater increases in soil fertility. Elevation and slope are two key factors that influence soil moisture after afforestation. These findings highlight the need for ongoing soil management and ecological maintenance in afforestation projects to sustain the soil fertility benefits. Our study provides a robust scientific foundation for afforestation strategies aimed at barren land restoration and offers valuable insights for policy formulation in barren land afforestation.