Xiaoqi Wang’s research while affiliated with Northwest A&F University and other places

Background Phosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear. Methods A greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days. Results (1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots’ promotion of aboveground biomass accumulation. Conclusion Despite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions.

Landslides cause significant disturbances to mountainous ecosystems and human activities. Due to climate change, the frequency of landslides as secondary disasters has notably increased compared to the past. Further exploration is needed to understand the effects of different restoration methods on post-landslide plant communities and soil properties over different periods of time. In this regard, we selected Lantian County in the northern foothills of the Qinling Mountains as our study area. We conducted surveys on artificially restored and naturally recovered plots at 1, 6, and 11 years after landslide events. Undamaged areas were chosen nearby as control plots. We identified vegetation types and species diversity after artificial and natural recovery and further analyzed the impact of different restoration strategies on vegetation patterns and soil properties. The research results indicate that, compared with natural recovery, artificial restoration can more quickly improve vegetation and soil. With the increasing time gradient, the average ground cover of the herbaceous layer in natural recovery decreased gradually from 47% at year one to 34% at year eleven. In contrast, in artificial restoration, the average ground cover of the herbaceous layer increased from 27% at year one to 44% at year eleven. For the shrub layer, in natural recovery, the average ground cover gradually increased to 39% over eleven years. While in artificial restoration, the average ground cover for the shrub layer gradually increased to 46% over the same period. In the artificial restoration plots, soil pH gradually increased (from 6.2 to 8.2), while TN content gradually decreased (from 1.7 g/kg to 0.9 g/kg). Similarly, TK content decreased (from 22.4 g/kg to 14.5 g/kg), and AP content showed a decreasing trend (from 20.7 mg/kg to 11.4 mg/kg). In the natural recovery plots, DNA content gradually increased (from 3.2 μg/g/d to 142.6 μg/g/d), and SC content gradually increased as well (from 2.4 mg/d/g to 23.1 mg/d/g). In contrast, on sites undergoing natural recovery, the short-term restoration rates of vegetation and soil are lower, but they show greater stability over a longer time. This study provides a new perspective on vegetation restoration strategies and is expected to offer insights for the optimization of post-landslide recovery in the future.

Over recent decades, there has been a severe nitrogen-deposition in alpine meadows which often leads to phosphorus limitation of plant productivity. In these high-altitude localities, Cyperaceae have an increasing biomass while other functional groups decrease. Meanwhile, Cyperaceae are known to have the ability of producing dauciform roots, which are formed under phosphorus limitation, but in China, are only described in these high-altitude places. So, is the superiority of Cyperaceae and the formation of dauciform roots in high-altitude localities related to the accumulation of nitrogen? And is there a link between them? A Carex filispica dominated community in Baima Snow Mountain was selected and quantitative fertilization with four levels of nitrogen and three levels of phosphorus was performed. After 2 weeks, Carex filispica individuals with and without dauciform roots were separated and analyzed for their regular root properties, dauciform root properties, biomass and chemical traits of above- and belowground parts. The total cover of the community declined under phosphorus limitation with increasing nitrogen supply, while the relative cover difference of Carex filispica increased with increasing nitrogen supply and decreased with increasing phosphorus supply. Dauciform roots had a more significant response to nitrogen supply than to phosphorus supply and they were formed the most at a low supply of nitrogen. The biomass and root properties of individuals with dauciform roots were enhanced by nitrogen supply and inhibited by phosphorus supply, while those of individuals without dauciform roots were often enhanced by phosphorus supply. Individuals with and without dauciform roots showed two different mechanisms, and were limited by significantly different factors, which can explain the opposite performance of Cyperaceae after nitrogen and phosphorus supply in previous studies.

Introduction The drought and phosphorus deficiency have inevitably become environmental issues globally in the future. The analysis of plants functional trait variation and response strategies under the stress of phosphorus deficiency and drought is important to explore their ability to respond to potential ecological stress. Methods In this study, Carex breviculmis was selected as the research object, and a 14-week pot experiment was conducted in a greenhouse, with two phosphorus treatment (add 0.5mmol/L or 0.05μmol/L phosphorus) and four drought treatment (add 0-5%PEG6000), totaling eight treatments. Biomass allocation characteristics, leaf anatomical characteristics, biochemical parameters, root morphology, chemical element content, and photosynthetic parameters were measured. Results The results showed that the anatomical characteristics, chemical elements, and photosynthetic parameters of Carex breviculmis responded more significantly to main effect of phosphorus deficiency. Stomatal width, leaf phosphorus content and maximum net photosynthetic rate decreased by 11.38%, 59.39%, 38.18% significantly (p<0.05), while the change in biomass was not significant (p>0.05). Biomass allocation characteristics and root morphology responded more significantly to main effect of drought. Severe drought significantly decreased leaf fresh weight by 61% and increased root shoot ratio by 223.3% compared to the control group (p<0.05). The combined effect of severe drought and phosphorus deficiency produced the highest leaf N/P ratio (291.1% of the control) and MDA concentration (243.6% of the control). Correlation analysis and redundancy analysis showed that the contributions of phosphorus and drought to functional trait variation were similar. Lower epidermal cell thickness was positively correlated with maximum net photosynthetic rate, leaf phosphorus, chlorophyll ab, and leaf fresh weight (p<0.05). Discussion In terms of response strategy, Carex breviculmis was affected at the microscopic level under phosphorus deficiency stress, but could maintain the aboveground and underground biomass well through a series of mechanisms. When affected by drought, it adopted the strategy of reducing leaf yield and improving root efficiency to maintain life activities. Carex breviculmis could maintain its traits well under low phosphorus and moderate drought, or better conditions. So it may have good ecological service potential in corresponding areas if promoted. This study also provided a reference for plant response to combined drought and phosphorus deficiency stresses.

Carex heterostachya and Carex breviculmis are easy to develop lawns in a short period while taking on high ornamental significance in northwest China where summer temperatures are high, rainfall is uneven, and soil is scarce. Several questions were raised, which are elucidated as follows: what type of plant functional characteristic has they formed for long-term survival and adaptation to this environment; which plant is more adaptable; which leaf functional characteristic are critical to photosynthetic characteristics. The following conclusions were drawn based on the exploration of the leaf functional characteristic of the two plants using gas exchange technology and field emission electron scanning technology: (a) C. breviculmis refers to a slow investment-return plant, exhibiting strong environmental adaptability and plasticity, and it is resistant to barrenness, drought, and shade. C. heterostachya refers to a type of quick investment-return plant, with high photosynthetic efficiency, well-developed transport tissue, and relatively shade-tolerant. The soil with low water content and poorer soil applies to C. breviculmis cultivation, and C. heterostachya applies to cultivation in the environment with sufficient light and rich nutrients. Moreover, C. breviculmis and C. heterostachya can be adopted to enrich the diversity of understory landscape. (b) Carex exhibits strong environmental adaptability, large variation in eco-physiological characteristics, as well as strong plasticity. Leaf anatomical characteristics are stable, whereas differences exist in the interspecific variability and plasticity. (c) when the genus Carex grew in the semi-shade and the soil environment was arid, specific leaf area (SLA) can become the main factor for the photosynthetic availability of Carex, the thickness of the stratum corneum, the thickness of the upper serve as secondary factors. The above-described findings can lay a theoretical basis for the cultivation and application of Carex and the expansion of turfgrass germplasm resources.

Carex heterostachya (CH) and Carex breviculmis (CB) are easy to develop lawns in a short period and exhibit high ornamental value in northwest China with high summer temperatures, uneven rainfall, and poor soil. Several questions are raised, including what type of plant functional traits has they formed for long-term survival and adaptation to this environment, which plant is more adaptable, as well as which leaf functional traits are critical to photosynthetic characteristics. After exploring the leaf functional traits of the two plants by gas exchange technology and field emission electron scanning technology, the following conclusions are drawn: (a) CB is a slow investment-return plant, which exhibits strong environmental adaptability and plasticity, and is resistant to barrenness, drought and shade. CH is a kind of quick investment-return plant, with high photosynthetic efficiency, well-developed transport tissue, and relatively shade-tolerant. The soil with low water content and poorer soil is suitable for CB cultivation, and CH is suitable for cultivation in the environment with sufficient light and rich nutrients. At the same time, both CB and CH can be used to enrich the diversity of understory landscape. (b) Carex have strong environmental adaptability, large variation in leaf structure traits, as well as strong plasticity. Leaf anatomical characters are stable, whereas there are differences in the interspecific variability and plasticity. (c) Specific leaf area (SLA) can serve as the main factor affecting the photosynthetic availability of Carex, the thickness of the stratum corneum(CUT), the thickness of the upper(UET) are secondary factors. These finding can provide a theoretical basis for the cultivation and application of Carex and the expansion of turfgrass germplasm resources.

Carex heterostachya (CH) and Carex breviculmis (CB) are easy to develop lawns in a short period and exhibit high ornamental value in northwest China. So, what type of plant functional traits has they formed for long-term survival and adaptation to this environment, which plant is more adaptable, as well as which leaf functional traits are critical to photosynthetic characteristics. The result of this study suggests that (1) CB is a slow investment-return plant with strong environmental adaptability and plasticity in long-term shaded environments. It is characterized by its weak photosynthetic capacity, smaller specific leaf area, low CO2 compensation point, high water utilization rate, high maximum carboxylation rate, as well as dark breathing rate. Moreover, it also has a thick cuticle, and epidermal cells make CB resistant to drought and barrenness. (2) CH is a quick investment-return plant, which is characterized by its higher photosynthetic rate, transpiration rate, stomatal conductance, as well as larger specific leaf area. With the increase of the temperature and photosynthetically active radiation, CH maintains high photosynthetic capacity by decreasing the transpiration rate and increasing the utilization rate of light energy. Its conducting tissue is well developed. CH have lower light saturation points and light compensation points, and CH was more shade-tolerant than CB. (3) Carex have strong environmental adaptability, large variation in leaf structure traits, as well as strong plasticity. Leaf anatomical characters are stable, whereas there are differences in the interspecific variability and plasticity. (4) Specific leaf area (SLA) can serve as the main factor affecting the photosynthetic availability of Carex, the thickness of the stratum corneum(CUT), the thickness of the upper(UET) are secondary factors. These finding can provide a theoretical basis for the cultivation and application of Carex and the expansion of turfgrass germplasm resources.