Effects of enclosure on biomass, carbon, nutrient storage and allocation for Seriphidium transiliense in a sagebrush desert grassland

摘要

We hypothesized that Seriphidium transiliense in a sagebrush desert grassland could improve the storage of biomass carbon and nutrient after 3 years of enclosure. Also, we expect distinctive allocation strategies of nutrient, carbon and biomass partitioning into root (R), root crown (RC), reproductive shoot (RS) and vegetative shoot (VS) plant characteristics or modules. Therefore, the storage and allocation pattern of biomass, carbon and nutrients (N, R K, Ca and Mg) in different modules were monitored during September and October, from 2009 to 2011. The results showed that the P content of root, the N content of reproductive shoot, the Ca content of root crown and vegetative shoot in enclosure of moderate degraded plot were significantly higher than outside plots (P<0.05). The storage of N, P, K significantly increased after enclosure (P<0.05). The storage of C, the biomass of reproductive shoot and vegetative shoot increased with the decreasing degradation intensity and the values increased in enclosure of moderate degraded plot. The proportion of N, K of reproductive shoot, the proportion of Ca, Mg and C of vegetative shoot, the ratios of N and C of root crown all showed an increasing trend after enclosure. The ratios of N and C of reproductive shoot in enclosure of moderate degraded plot were significantly higher than outside plots (P<0.05). The present results suggested the nutrient elements supply capacity of the soil, the resource allocation to vegetative shoot and reproductive shoot allincreased in the sagebrush desert grassland after enclosure. The improvement of soil and these performances of Seriphidium transiliense population were beneficial to its ecological restoration.