RESUMEN
As an important ecological barrier for the North China Plain, research on the spatial variations of soil nutrients in the southern foot of the Taihang Mountains is of great significance for the forestry ecological construction in this rocky mountainous area. With the typical slopes (the artificial forestland and the natural wild slope) of the southern foot of the Taihang Mountains as the research objects, we used the grid method to arrange sampling points, and combined classical statistics, geostatistics and constrained sorting methods to analyze the spatial variations of soil nutrients. The results showed that: 1) soil total carbon (TC) contents were 6.80-57.05 g·kg-1, and the total nitrogen (TN) contents were 0.74-3.93 g·kg-1. The coefficients of variation of both soil TC and TN were 25.0%-52.8%, belonging to the moderate degree of variation, which were caused by the combination of random and structural factors. The spatial aggregation of soil nutrients decreased with increasing lag distances. 2) The contents of soil nutrients had increasing trends from the top to the bottom of the slopes, with high nutrient values appearing at the bottom of the slopes. 3) The soil bulk density, gravel content, vegetation coverage, and soil water content were the main factors affecting the spatial variability of soil TC and TN on the southern foot of the Taihang Mountains. 4) Soil water content was the main factor affecting soil nutrients at the natural wild slope, but not at the artificial forestland.
Asunto(s)
Nitrógeno , Suelo , Carbono/análisis , China , Bosques , Nitrógeno/análisisRESUMEN
To explore the effects of forest types and slope positions on the content of soil organic carbon (SOC) and total nitrogen (TN) in the lower hilly area of Taihang Mountains, we examined the distribution pattern of SOC and TN contents in Quercus variabilis plantation (Qo), and Platycladus orientalis plantation (Po), and abandoned land (Al). The results showed that in the same forest type or slope position, the contents of SOC and TN gradually decreased with increasing soil depth. Under different slope conditions, the contents of SOC and TN showed the tendency of upper-slope (U) > middle-slope (M) > lower-slope (L) in the planted forests (Qo and Po), but showed the tendency of L>U>M in Al. Under different forest types, the contents of SOC and TN in the U and M showed the trend of Qo>Po>Al. At the LS, the contents of SOC and TN of Al were the highest. The C/N ratio followed an order of Qo>Po> Al at U and M, while Qo>Al> Po at L. Within the same forest type, C/N of different slopes was different, but not significant. Our results suggested that the adaptability of the Qo plantation is the best in the lower hilly area of Taihang Mountains.