The authors measured root morphological and architectural traits of 22 different dominant plant species across 16 Inner Mongolia grassland sites along soil water gradients, and analyzed the response of these root traits (diameter, length, SRL, RTD, BrIntensity and BrRatio) to four environmental factors (MAT, MAP, Soil N and Soil C). The results showed that variation of absorptive root diameter, tissue density and specific root length among different species was 7, 9, and 15 times, respectively. There was a significant positive correlation between root diameter and lateral root length, but negative correlation between root diameter and root branching intensity. Responses of both absorptive and non-absorptive roots to precipitation and soil nitrogen were species-specific. When using different combinations of root traits to describe plant adaptation strategies, different species’ root traits respond to environmental changes with different degrees and direction of variation, resulting in a diversity of plant adaptation strategies.

Three urban parks along a building density gradient (indicating a gradient of human disturbance) in Shenzhen were chosen as the sampling sites, and in each park, three vegetation types (lawn, high forest and Lichi forest) were selected to sample soils, with a rural forest of Wutongshan as the reference. The results showed that soil bulk density and pH value in the urban sampling sites were higher than those of the rural forest, exceeding the optimal range of plant growth. Soil carbon and nitrogen concentrations and fine root biomass in urban sampling sites were lower than those of rural forest. However, soil phosphorus concentration in urban sampling sites was higher than those of rural forest, particularly indicated by phosphorus eutrophication in Lichi forests. Soil carbon concentration, nitrogen concentration and fine root biomass were positively related to each other, indicating that urban plant growth may be constrained by soil nitrogen, and that fine root inputs may have contributed substantially to soil organic matter. The results suggest that soil carbon, nitrogen, phosphorus and root biomass in urban green lands were affected by vegetation type and building density. The results may have important implications for green land construction and management: lawns are able to accumulate soil carbon and nitrogen rapidly in the shallow soil layer, and Lichi forests are better to accumulate soil carbon and nitrogen concentration in deeper soil layer. In addition, aboveground litter should not be removed in urban high forests in order to increase soil carbon and nitrogen concentrations.

To examine patterns of nutrient concentrations in different organs, stoichiometry of various nutrients, and the relation of nutrient concentrations with species and the environment, the concentrations of total non-structural carbohydrate (TNC), nitrogen (N), and phosphorus (P) among leaves, stems, tap roots, and first order roots in Asian white birch (Betula platyphylla) and Meyer spruce (Picea meyeri) were studied. The two species were located in the southeastern edge of Inner Mongolia. For TNC, leaves had the highest and first order roots had the lowest concentrations ; the largest difference between them was less than 53%. For N and P, however, there were much higher concentrations in leaves and first order roots than that in stems and the tap roots; the largest difference between them was about 98%. These patterns were determined by the physiological roles (carbohydrate production, nutrient uptake and storage, etc.) that different organs play. In addition, both TNC∶ N and TNC∶ P of Meyer spruce were higher than those of Asian whiter birch, reflecting the physiology of different species and variations in soil nutrient conditions.