[Spatial Variability in Soil Respiration Under Different Land Use Patterns in Maocun Village, Guilin]

To investigate the factors influencing the spatial variability in soil respiration among different land use patterns in a karst non-karst interactive distribution area, field experiments were conducted in Maocun Village, Guilin. Soil respiration, δ¹³C-CO₂ value, and relevant environment, vegetation, and soil factors were measured. The spatial variability in soil respiration and the relationship between soil respiration and these measured factors were examined. The results indicated that soil respiration rates ranged from 1.39 μmol·(m²·s)^-1 to 5.31 μmol·(m²·s)^-1, with the highest value being approximately 3.8 times the minimum. Soil respiration varied significantly among different land use patterns under different lithology zones. The soil respiration rate of the G2 pines in the same lithology area was 2.3 times higher than that in the orchard G1 point after the destruction of the forest. The soil respiration caused an increase in CO₂ concentration in the atmosphere and a decrease in the δ¹³C-CO₂ value; the relationship between the two could be described by an inverse proportional function. The study found that in mid-April, the average water heat condition was close to that of the entire year. The difference in soil organic carbon content caused by land use was a driving factor of the spatial variability in soil respiration. In all ecosystems studied, the relationship between soil respiration and soil organic carbon content and total nitrogen content could be described by a two-element linear regression equation and explained 92.8% of the spatial variability in soil respiration.