Sand-fixing characteristics of Carex brunnescens and its application with straw checkerboard technique in restoration of degraded alpine meadows

Abstract

Carex brunnescens (Pers.), a typical clonal species, is considered to be the only herb found to date that can develop on sand dunes in Maqu alpine region of northwestern China. However, the characteristics that C. brunnescens resists to harsh alpine environment have not been documented. In this study, we conducted a field investigation to determine the morphological, reproductive, and sand-fixing characteristics of C. brunnescens. Concomitantly, we transplanted the belowground rhizomes of C. brunnescens to sand dunes and compared the abilities to restore degraded alpine meadows among sand dunes that had no further treatment (SD+N), sand dunes that had straw checkerboard technique but no transplanted rhizomes of C. brunnescens (SD+SCT), and sand dunes that had both SCT and transplanted rhizomes of C. brunnescens (SD+SCT+P). We found that belowground vertical rhizomes and horizontal rhizomes (including branching rhizomes and main rhizomes) of C. brunnescens were highly developed and that population reproduction was dominated by horizontal rhizomes. C. brunnescens exhibited a significant sand-fixation effect under following conditions: population density was 145-156 ramets/m 2 , vegetation cover was 31.2%-39.3%, total length of belowground rhizomes was 11,223 cm/m 2 , total length of belowground first-order roots was 9161-10,524 cm/m 2 , fresh weight of aboveground part was 198.5-212.6 g/m 2 , and fresh weight of belowground part was 578.8-612.4 g/m 2. It should be particularly noted that SD+SCT+P treatment (sand dunes that had both straw checkerboard technique and transplanted rhizomes of C. brunnescens) was the best and SD+N (sand dunes that had no further treatment) was the worst in terms of following biotic indicators: total number of reproductive ramets, total number of belowground rhizomes, and fresh weight of aboveground and belowground parts of C. brunnescens, contents of soil organic carbon, available nitrogen, microbial biomass carbon, and microbial biomass nitrogen. It implies that applying SCT in sand dunes and transplanting belowground rhizomes to sand dunes with SCT could improve both soil fertility and growth of C. brunnescens. These results suggest that the SCT-promoted high reproductive abilities of belowground rhizomes of C. brunnescens can successfully facilitate the establishment of ramets and can thus be an effective strategy to restore degraded vegetation in Maqu alpine region of northwestern China.

Cascading implications of a single climate change event for fragile ecosystems on the Qinghai‐Tibetan Plateau

“…Furthermore, these sandstorms may threaten the entire TRHR and the services (i.e., water provision) which the area is responsible for. In this case, ecologically sound interventions such as aircraft sowing of drought‐resistant vegetation within the spit or straw checkerboard barriers (Lü et al 2016, Kang et al 2017) should be carefully explored. In addition, fixed or mobile observation equipment, such as video and infrared cameras, should be built in the lambing area to accurately monitor and assess changes in the number and migration habits of Tibetan antelopes.…”

Silicon accumulation by Phragmites australis positively responds to rise in groundwater depth in the desert oasis areas of the HeXi Corridor, China

“…In short, the Si‐rich characteristics of P. australis are a comprehensive genetic performance of long‐term adaptation to unfavorable environments. Each plant has formed complex survival mechanism for adapting to adversity to make them survive, multiply, and develop in special environments (Bradshaw & Hardwick, 1989; Gutterman, 1993; Kang et al, 2017). Therefore, it is worth investigating deeply to elaborate the intricate physiological and ecological adaptive mechanisms.…”

The Physical and Chemical Properties of Soil Crust in Straw Checkerboards with Different Ages in the Mu Us Sandland, Northern China

“…Afterwards, the invasion and development of drought-resistant microorganisms help to form a biological crust gradually [4]). Soil crusts play a major role in water and nutrient fluxes in arid and semi-arid regions, contributing to the spatial arrangement of vegetated and open areas [5,6]. There are some publications on the composition of soil crusts in arid and semi-arid regions.…”

“…Due to drought and low fertilization, especially a lack of N and P, soil crusts are considered to be nitrogen fixers [5]. A study found that soil crusts can dramatically increase the surface 5 cm of soil organic matter content [11].…”