[Spatial variations and its influencing factors of soil carbon and nitrogen on the southern foot of Taihang Mountains, China].

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.

[Spatial distribution of plant diversity in shrub layer of plantation and its relationship with light environment].

We analyzed the spatial heterogeneity of plant species diversity in shrub layers and its relationship with light environment in plantation and - mixed forest, following the method of geostatistics. The results showed that plant species diversity indices (Shannon , Simpson , Margalef ) of shrub layers in plantation were significantly lower than that in - mixed forest. The variation ranges and spatial autocorrelation distances of plant species diversity index in plantation were higher than that in - mixed forest, with lower spatial homogeneity but stronger spatial dependence.

[Distribution characteristics of surface soil organic carbon and total nitrogen in forest plantation of hilly area of Taihang Mountains, Chin].

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.

Demographic expansion of two Tamarix species along the Yellow River caused by geological events and climate change in the Pleistocene.

The geological events and climatic fluctuations during the Pleistocene played important roles in shaping patterns of species distribution. However, few studies have evaluated the patterns of species distribution that were influenced by the Yellow River. The present work analyzed the demography of two endemic tree species that are widely distributed along the Yellow River, Tamarix austromongolica and Tamarix chinensis, to understand the role of the Yellow River and Pleistocene climate in shaping their distribution patterns.