Aims Grasslands provide many kinds of ecological services, including carbon sequestration, sand fixation, and biodiversity maintenance. However, some grasslands are experiencing degradation. To provide scientific theoretical support for grassland restoration, it is necessary to understand the limiting factors for vegetation restoration in degraded grasslands. In this study, we explored nutrient limiting factors for vegetation restoration under different degradation stages in typical steppe of Nei Mongol.

Methods Plant and soil samples were collected during August in 2021-2022, from 13 sampling sites (four plant communities under different degradation stages within each site: non-degradation, light degradation, moderate degradation, and heavy degradation) in typical steppe. We examined the effects of degradations on above-ground biomass, coverage, and density of plant communities. Soil organic carbon, nitrogen and phosphorus contents were measured. Multiple statistical analyses, including least squares regression analysis, redundancy analysis, and multiple linear regression analysis, were used to clarify the nutrient limiting factors for vegetation restoration in degraded grasslands.

Important findings Plant community above-ground biomass, coverage, and density, as well as the contents of soil organic carbon, total nitrogen, and available phosphorus significantly decreased with the intensification of degradation. Under the whole degradation sequence and adjacent degradation succession stages, soil nitrogen content was the most influential factor on plant community properties, while soil phosphorus content marginally affected the overall degradation sequence. These results indicate that soil nitrogen availability is the most important nutrient factor limiting vegetation restoration. Consequently, nitrogen fertilization should be concerned in the future restoration works.

Aims Soil extracellular enzymes are crucial for soil organic matter decomposition and nutrient cycling. Soil enzyme activity and stoichiometry can provide insights into microbial resource limitations and soil nutrient availability. This study investigated the effects of grazing, particularly overgrazing that often leads to grassland degradation, on soil enzyme activity and stoichiometry, and identifies nutrient limitations in temperate grasslands.

Methods We conducted grazing experiments with varying stock rates in a typical steppe of Nei Mongol, and investigated the changes in the activities and stoichiometric ratios of soil extracellular enzymes. Enzyme activities related to carbon (C), nitrogen (N), and phosphorus (P) cycling were analyzed, and a vector model was applied to determine soil nutrient limitations under different grazing intensities.

Important findings 1) Soil hydrolase activities in the studied grassland ranged from 0 to 300 nmol·g^-1·h^-1, which is relatively low compared with the global averages. Grazing intensity significantly impacted the activities of soil enzymes, including α-glucosidase, cellulose hydrolysis, xylosidase, β-d-cellubiosidase, β-1,4-N-acetylamino-glucosidase, glycosaminidase, leucine aminopeptidase, and acid phosphatase. The enzyme activities peaked under moderate grazing and recommended grazing. 2) The Standardized Major Axis (SMA) regression analysis revealed strong linear relationships between the enzyme activities associated with C, N, and P cycling. The soil enzyme C:N:P stoichiometric ratio was 1:2.3:1.3, deviating from the global average 1:1:1. 3) The vector model based on soil enzyme stoichiometry indicated that the grasslands were co-limited by N and P, with P limitation becoming more pronounced as grazing intensity increased in Nei Mongol.

Aims The influencing factors on the loss and accumulation of soil organic carbon in degraded grasslands need to be clarified. The lignin phenols derived from plant are important composition of soil organic carbon, and the decomposition of lignin phenols caused by benzene ring opening is an important process of soil organic carbon loss in degraded grasslands, however, studies on this point are not fully understood.

Methods Soil samples were collected in four degradation severities of typical grasslands in Xilin Gol, Nei Mongol. The content of lignin phenolic and the abundance of the key functional gene for benzene ring opening, catechol-1,2-dioxygenase gene (catA), and product (cis,cis-muconic acid) were measured. And variations of lignin phenols and the abundance of catA gene along the degradation gradient and their correlation with soil organic carbon content were also analyzed.

Important findings The results showed that 1) compared to the non-degraded grasslands, the content of lignin phenols in the soil of light, medium, and severe degraded grasslands decreased significantly, and showed a decreasing trend with increasing degradation. The content of lignin phenols showed the same pattern with significantly positively correlation with soil organic carbon content. 2) The abundance of catA gene significantly increased in degraded grasslands, and the abundance of its decomposition product cis,cis-muconic acid was significantly higher in moderate and severe degradation compared to that in the light and non-degradation grasslands. 3) The abundance of catA gene was significantly positively correlated with the abundance of cis,cis-muconic acid, while the content of lignin phenols was significantly negatively correlated with the abundance of catA gene. The abundance of catA gene and cis,cis-muconic acid were both significantly negatively correlated with soil organic carbon content. The results showed that, at the sample site scale, the decomposition of lignin phenols caused by benzene ring opening could be a potential mechanism in explaining the changes in soil organic carbon content in degraded typical grasslands in Nei Mongol. Thus, our results are expected to provide a new perspective for the driving mechanism of soil organic carbon loss and accumulation in degraded grasslands, and thereby providing a certain theoretical basis for the restoration of degraded grasslands.

Aims China harbors extensive grassland resources, yet nearly 70% of these grasslands are afflicted by varying degrees of degradation under the combined pressure of climate change and human activities. Pinpointing the pivotal factors driving grassland degradation and establishing a rapid diagnostic system is imperative for precise condition assessments.

Methods This study was conducted in the Hulun Buir meadow steppe of Nei Mongol. The selected sites were categorized into four degradation levels: non-degraded, lightly degraded, moderately degraded, and heavily degraded. Vegetation and soil indicators were collected. Leveraging the random forests algorithm, degradation indicators were screened and weighted, with efforts made to reconcile ecosystem service priorities between the government and pastoralists.

Important findings This study identified ten key factors characterizing degradation, including aboveground biomass, proportion of high-quality forage, community height, litter biomass, species richness, leaf dry matter content, leaf thickness, soil density, soil water content and soil inorganic water content. These indicators encapsulate diverse ecosystem services, including forage supply, erosion control, biodiversity conservation, vegetation resilience, and water and nutrient regulation. Using non-degraded sites as a benchmark, a degradation index (DI) for the meadow steppes of Nei Mongol was developed, accompanied by delineated DI thresholds for different degradation levels. This study provides foundational data to support judicious selection of indicators for both national and regional standards.

Aims Vegetation-soil nutrient interation is a key process in maintaining stability and multifunctionality of terrestrial ecosystems. However, vegetation-soil interaction on carbon (C), nitrogen (N) and phosphorus (P) and the key drivers in promoting plant succession during sandy land restoration are still unclear. In this study, based on ecological stoichiometry theory, the vegetation-soil nutrient interaction in sandy land from the perspective of soil microorganisms was explored, and the limiting factors for ecological restoration of degraded vegetation in sandy land were also investigated.

Methods We selected different landscape types in Hulun Buir Sandy Land, including mobile dunes, semi-mobile dunes, semi-fixed dunes, fixed dunes, and sandy grassland. The space-for-time substitution approach was used to investigate the characteristics of the C, N, and P stochastic geometries of the vegetation-soil coordination equilibrium and the key drivers in the restoration processes. In addition, a correlation analysis between vegetation-soil stoichiometry and soil microbial communities was performed to reveal multiple driving mechanisms of soil physicochemical factors, plant communities, and soil microbial communities on plant-soil stoichiometry during plant restoration in degraded sandy areas.

Important findings 1) With vegetation restoration in degraded sandy land, soil C, N, and P contents, as well as the ratio of C:P and N:P showed significant increasing trends. Conversely, C, N, and P contents and their stoichiometry in living plants and roots did not show clear trends. These results suggest that sandy plant communities are still capable of maintaining their nutrient balance, and that their stoichiometric balance is relatively stable with environmental conditions recover and change. 2) Soil C:P (12.08-38.40) was at a low level, resulting in net soil P mineralization, and microbial decomposition of organic matter was not limited by P, and above-ground plant N:P was all lower than 10, indicating that the growth of vegetation in Hulun Buir Sandy Land was mainly limited by N. 3) Meanwhile, the soil N:P continued to increase, indicating that the supply of soil N gradually increased, while the supply of P gradually decreased, and P could be a limiting element in the later stages of vegetation restoration. 4) During vegetation restoration in the Hulun Buir Sandy Land, soil stoichiometry and pH had direct significant positive effects on plant stoichiometry, while soil microorganisms indirectly affected plant stoichiometry by regulating soil stoichiometry. In addition, the indirect effects of soil moisture, soil texture, and electrical conductivity on soil and plant stoichiometry should not be neglected. Thus, this study provides a theoretical basis for adaptive management and prediction of ecosystem restoration in degraded sandy soils.

Aims The alpine meadows on the eastern Qingzang Plateau have degraded in some areas due to long-term overgrazing. As a crucial resource for degraded ecosystem restoration, the dynamics of soil seed banks and their role in degraded alpine meadow restoration remain unclear.

Methods We chose four different degradation levels of alpine meadows to construct a degradation gradient on the eastern Qingzang Plateau. We investigated the plant community and soil seed bank along the degraded gradient, explored the changes of plant community and seed bank along the degradation gradient, and analyzed the potential role of seed banks in alpine meadow regeneration and degraded alpine meadow restoration.

Important findings The results showed that: 1) the species richness and relative abundance of the plant community decreased significantly along the degradation gradient, but the species richness of the seed bank increased first and then decreased, and the seed density decreased significantly along the degraded gradient. 2) The similarity of species composition between the plant community and soil seed bank gradually increased with the degradation gradient, which suggests that the role of soil seed bank in plant community regeneration increased along the degraded gradient. 3) Compared with the plant community, there is a hysteresis response of the soil seed bank to alpine meadow degradation, which can buffer the influence of alpine meadow degradation on the plant community to a certain extent. Our findings indicated that the different responses of plant community and soil seed bank to degradation, and soil seed bank is crucial for the degraded alpine meadow restoration on the Qingzang Plateau. However, the potential role of the seed bank in the degraded alpine meadows restoration will be limited because of the depletion of seed bank resources at the seriously degraded level. These results can provide a scientific basis for the protection, restoration, and management of degraded alpine meadows on the Qingzang Plateau.

Aims During the past decades, about a half of the global grasslands have been degraded as the results of climate change and anthropogenic activities. Grassland degradation substantially alters plant diversity and community composition; however, it remains elusive how these changes link to ecosystem productivity across broad geographic scales.

Methods Using a standardized survey from 45 grassland degradation sequences at 15 sites across three grassland types (i.e., alpine steppe, alpine meadow and alpine swamp meadow) on the Qingzang Plateau, we aim to explore changes in plant diversity and functional groups upon grassland degradation and their linkages with aboveground net primary productivity (ANPP).

Important findings Across the three grassland types, species richness, Shannon-Weiner diversity index, Simpson diversity index and Pielou evenness index all exhibited a first increase and then decrease pattern as degradation intensified. The coverage of sedge and grass declined, but legume coverage showed no significant changes and forb coverage increased along the degradation gradient. Mixed-effects models showed that degradation-induced change in ANPP was mainly associated with changes in coverage of original dominant species but minimally influenced by plant diversity for all grassland types. These results indicate that the degradation-induced productivity reduction is caused by the decline in dominant species rather than losses of plant diversity. The findings mentioned above provide important clues for alpine grassland restoration: restoring dominant species would be an effective approach for boosting ecosystem productivity in degraded grasslands on the Qingzang Plateau.

Aims Reseeding is one of the key measures for grassland restoration, and selecting reseeding species and their combination is crucial for the restoration effect. The key to grassland restoration is how to rationally combine multiple species to maximize functional complementarity and ensure community stability and multifunctionality.

Methods This study conducted a multi-species combination experiment of native grasses in a typical degraded alpine meadow in Maqu County, Gansu Province.

Important findings The results showed that multi-species reseeding significantly increased the biomass, coverage and species richness of the grassland. We comprehensively evaluated the indexes of aboveground biomass, species richness and proportion of high-quality forage in grassland after mixed reseeding different species combinations. Eventually, the combinations with better performance were screened out as: combinations based on grass mixtures: Elymus nutans + Festuca sinensis + Poa pratensis + Festuca rubra+ Poa crymophila + Puccinellia tenuiflora; combinations based on grass-legume mixes: Elymus nutans + Festuca sinensis + Poa pratensis+ Festuca rubra+ Tibetia himalaica + Medicago ruthenica and Elymus nutans + Festuca sinensis + Poa pratensis + Festuca rubra+ Tibetia himalaica + Medicago ruthenica + Vicia unijuga + Astragalus laxmannii; combinations based on grass-legume-sedge mixes: Elymus nutans + Festuca sinensis + Poa pratensis + Festuca rubra+ Tibetia himalaica + Medicago ruthenica + Vicia unijuga + Astragalus laxmannii +Cyperaceae. These multi-species mixing combinations maintained better community stability and grass production performance during the restoration of alpine degraded meadows in Gannan. This study can provide a reference for alpine grassland restoration in similar degraded areas.

Aims Constructing multifunctional group species combination model is crucial for restoring severely degraded alpine grassland. However, the responses of multifunctional group species combination to severely degraded alpine meadows and relationship between plant diversity and ecosystem multifunctionality on the Qingzang Plateau remain unclear.

Methods In the study, we focused on the severely degraded alpine meadow at the Maqên County in the Sanjiangyuan Nature Reserve, and constructed four species combination models including grass mixture, grass + legume mixture, grass + legume + sedge mixture and grass + legume + forb mixture. The study evaluated the ecosystem multifunctionality under different species combination models by measuring plant diversity, primary productivity, and soil factors. Furthermore, the relationship between plant diversity and ecosystem multifunctionality was analyzed.

Important findings The results showed that: (1) Among the four species combination modes, the grass + legume + sedge mixture had the highest species richness and Shannon-Wiener index, whereas there was no significant differences in Simpson index and Pielou index between the multifunctional group species combination models. (2) The biomass increased significantly with the addition of plant functional group numbers, and was the highest in the grass + legume + sedge mixture. (3) Except for pH, conductivity, and available phosphorus content, all other indicators increased significantly under the grass + legume + sedge mixture. (4) Ecosystem multifunctionality was the highest under the grass + legume + sedge mixture, and the ecosystem multifunctionality showed decreasing pattern along with the increase of plant diversity. Our results indicated that the grass + legume + sedge mixture has a significant impact on promoting the recovery of soil nutrients and improving primary productivity in severely degraded alpine meadows. The study provides a multifunctional group species combination reference for the restoration of severely degraded alpine meadows in the Sanjiangyuan region, and is of great significance for promoting the theoretical development of ecological restoration in severely degraded alpine meadows on the Qingzang Plateau.

Aims Seed coating is an effective measure to enhance seedling establishment and growth in extreme environment. Currently, seed coating is most commonly used in crops, this study designed multiple seed coating formulations to address poor field emergence and low establishment rates of major reseeding grass species on the Qingzang Plateau. Our work aims to providing technical support for efficient application of native grass species in restoring degraded alpine grasslands on the Qingzang Plateau.

Methods We designed multiple seed coating formulations using different levels of nutrients (N), microbial inoculants (MC), and growth regulators (G). We performed laboratory growth experiment and field experiments to evaluate the effects of different seed coating treatments on the seed emergence and growth of three grass species.

Important findings Emergence rates of Elymus nutans and Poa pratensis treated with microbial fertilizers + compound microbial inoculant + growth regulator (NMCG) were higher than those treated with other formulations. Such a formulation increased the emergence rates by 27% and 44% compared with the control (filler coating, CK3), respectively. Both the aboveground and belowground biomasses of Elymus nutans treated with microbial nutrients + microbial inoculant (NMC) were the highest. The above-ground biomasses of Festuca sinensis treated with compound microbial inoculant (MC2) were the highest, and the below-ground biomasses of Festuca sinensis treated with NMC were the highest. The above-ground and below-ground biomasses of Poa pratensis treated with NMCG were the highest. The field experiment showed grasslands reseeded with seeds treated using NMCG, they had the highest height, coverage, and above-ground/below-ground biomass. The restoration effects of other formula-coated reseeding were also better than those of grassland (CK1). Finally, all coating formulation containing microbial inoculants significantly increased the proportion of high-quality forage grass species in the restored grassland.

Aims The severe degradation of grassland ecosystems is restricting China’s ecological security and economic development, and this makes it a scientific and technological challenge for pastoral areas to effectively restore degraded grasslands. To date, multiple grazing management and human assisted improvement techniques have been developed, the implementation of these techniques played important roles in grassland restoration, but their effectiveness was constrained for degraded grasslands with severe damaged community structure and propagule shortage.

Methods We introduce a propagule regulation technique which can remove propagule limitation and target at restoring moderately and severely degraded grasslands. This technique includes two key technical aspects, namely, cultivation and transplantation of “propagule island”. The cultivation of “propagule island” is planting high-quality forage combining with nutrient management to promote the rapid growth of rhizomes (or lateral buds), i.e., cultivating “propagule island” with rich propagule pool (tiller rhizomes or branching buds). The transplantation of “propagule island” is replenishing the propagule pool to degraded grasslands, and restores grasslands relying on clonal growth (or asexual reproduction) of high-quality forage.

Important findings The main purpose of this technique is to rapidly restore the structure and function of communities in degraded grasslands taking the advantages of clonal growth of high-quality forage. According to the technical demonstration in the meadow grassland, “propagule island” of Leymus chinensis and Medicago falcatahad significant effects on restoration, and they increased the productivity of the two communities from 214.5 to 358.7 and 286.4 g·m^-2, respectively. They also increased the proportions of high-quality forage from 18.4% to 54.7% and 31.5%, respectively. This technique can provide important data and technical supports for the targeted restoration of propagule-restricted grasslands.

Aims In China, the restoration of degraded grasslands is impeding the management of grasslands and their sustainable utilization. Soil nutrient deficiency is one of the main constraints for restoring degraded grassland. The essence of soil nutrient regulation is to restore the original dominant species, promote grassland productivity and the occupancy of high-quality forage in degraded grasslands, and meanwhile diminish the negative environmental effects caused by nutrient addition.

Methods Taking advantage of a restoration experiment carried out in a degraded grassland of Hulun Buir, in terms of the deficient soil nutrients, the limiting elements for plant growth and the nutrient specificity for different plant species, we developed soil nutrient regulation technique.

Important findings The key technical points are as follow: demand-based dosage, synergy of nitrogen and phosphorus, microelements supplemention, early-spring fertilization, deep fertilizaiton and strip operation. Soil nutrient regulation technique has broad prospects in application in Hulun Buir grassland, China. Improving the productive and ecological functions of degraded grasslands is of great significance for increasing the income of farmers and herders, ensuring the security of fodder grass supply, and safeguarding ecological security and national unity in northern China.

Aims Leymus chinensis grassland is one of the most representative vegetation types in northern temperate grassland of China. Overgrazing causes great decline in the proportion of L. chinensis biomass to community biomass. Application of organic and inorganic fertilizers can significantly promote the recovery of L. chinensis population, but the underlying mechanisms are still poorly understood.

Methods In a degraded L. chinensis grassland in Hulun Buir, the effects of organic and inorganic fertilizers on plant community, L. chinensis populations and individuals were explored with the same amount of nitrogen (10 g·m^-2·a^-1) and phosphorus (3 g·m^-2·a^-1) application.

Important findings At the plant community level, the application of organic and inorganic fertilizers both consistently and significantly increased above-ground biomass in all three years (2021-2023), with the higher biomass under organic fertilizer application. While the application of organic fertilizer significantly reduced the species richness in the second and third year at community level. At the population level, both organic and inorganic fertilizers significantly increased the aboveground biomass of L. chinensis and its proportion in community-level biomass, with higher values under organic fertilizer application. In the third year, the density of L. chinensis with inorganic and organic fertilizer treatments significantly increased by 1.79 and 8.89 times, respectively. At the individual level, the biomass of L. chinensis with inorganic and organic fertilizer treatments significantly increased by 85.3% and 69.1%, respectively. Variance partition analysis suggested that the population density and individual biomass respectively explained 81.8% and 6.2% of the variation in population biomass of L. chinensis. Our results suggested that the application of organic or inorganic fertilizer can promote the restoration of degraded L. chinensis grassland. The increase in population density rather than individual biomass of L. chinensis is the predominant mechanism for its population recovery.

Aims Declining soil quality is one of the key limiting factors for recovery in moderately degraded alpine meadows. Furthermore, the irrational application of nitrogen and phosphorus fertilizers has a significant negative effect on the biodiversity of the Qingzang Plateau. However, there have been limited studies on the soil quality improvement techniques for moderately degraded alpine meadows on the Qingzang Plateau from a systematic perspective. The objective of this study was to investigate the effects of nitrogen and phosphorus fertilizers and microbial fertilizers on soil chemical properties and enzyme activities in moderately degraded alpine meadows.

Methods This study investigated the plant community characteristics, soil physicochemical properties and enzyme activities of different treatments under different treatments, including nitrogen and phosphorus fertilizers coupled with microbial fertilizers, in moderately degraded alpine meadows on the Qingzang Plateau.

Important findings The results indicated that both nitrogen and phosphorus fertilizers, when coupled with microbial fertilizers, significantly increased aboveground biomass. A significant interaction was observed in the effects on soil nutrient-related indexes, conductivity, and enzyme activities associated with carbon, nitrogen and phosphorus cycling. Overall, the application of both nitrogen and phosphorus fertilizers, in combination with microbial fertilizers, demonstrated clear restoration effects on moderately degraded alpine meadows. Microbial fungal fertilizers were found to enhance soil multifunctionality, and the combination of nitrogen, phosphorus, and microbial fertilizers yielded better results than the application of nitrogen and phosphorus fertilizers alone. The optimal physiological response was observed with the application of 45 kg·hm^-2nitrogen, 20 kg·hm^-2 phosphorus, and 225 kg·hm^-2microbial fertilizers. These findings provide a scientific basis for promoting the restoration of moderately degraded alpine degraded meadows on the Qingzang Plateau and enhancing ecosystem service functions.

Aims Most of the grasslands in the Sanjiangyuan area are degraded to varying degrees, and planting artificial grassland is an important measure to restore the ecological function of severely degraded grasslands. Moss crust affects soil nutrient cycling and the structure of microbial communities, so it is critical to investigate the feasibility of using moss crust to promote the restoration of degraded grasslands to understand the ecological role of bioconjugate crusts and develop reasonable and effective ecological restoration measures.

Methods In this study, four different grass combinations and three types of moss crust inoculation were set up to investigate the effects of moss crust inoculation on the soil microenvironment of artificial grassland in the “black soil beach” of Sanjiangyuan.

Important findings Moss crusts increased soil organic carbon, available phosphorus, ammonium nitrogen contents, and nitrate nitrogen contents, and available nutrients content were significantly higher in the artificial grassland than in the “black soil beach”. Actinobacteria, Proteobacteria, Acidobacteriota, Chloroflex, and Firmicutes were the top 5 dominant taxa in terms of mean relative abundance at the phylum level for bacteria, while Ascomycota, Basidiomycota, Mortierellomycota, unclassied_k_Fungi, and Olpidiomycota were the top 5 dominant taxa in terms of mean relative abundance at the phylum level for fungi. With the increase of moss crust inoculation, the number of bacterial operational taxonomic unit (OTUs) decreased and the number of fungal OTUs increased, and the moss crust inoculation did not significantly affect the microbial diversity index. The mixed-effects model results indicated that the moss crust significantly had a significant effect on the effective phosphorus, nitrate nitrogen, ammonium nitrogen contents, and microorganisms affecting their accumulation. Redundancy analysis shows that the bacterial community structure is susceptible to soil factors. Mantel test results showed that moss crust A1 (700 g·m^-2) inoculation had a significant effect on bacterial community composition than fungal community. Additionally, effective phosphorus, ammonium nitrogen, and nitrate nitrogen contents were positively correlated with the bacterial community. The above findings suggest that moss crust inoculation may affect soil nutrient accumulation and cycling by altering the microbial community environment, as well as promote the recovery of ecological function of the artificial grassland in Sanjiangyuan, providing a theoretical basis for future research into moss crust addition to restore the ecological function of soil in extremely degraded grassland.

Aims The application of growth promoter is an important tool for ecological restoration of degraded grassland by human intervention. Therefore, the aim of this study is to investigate the growth promoting effect of dry mycelium of Penicillium chrysogenum (DMP), a residue from the industrial production of penicillin, on the growth and physiological performance of Trifolium repensand Lolium perenne.

Methods In this study, we mainly applied pot experiment and field experiment to investigate the growth promoting effect of DMP addition on the performance of T. repens and L. perenne. Then we applied transcriptome sequencing to determine the molecular mechanism of DMP promoting effects on forage growth.

Important findings The results of this study are as follows: (1) DMP addition can significantly improve their physiological indices and enhanced developmental morphological traits of T. repens and L. perenne. Compared with the compound fertilizer treatment, the application of 4.50 g DMP per pot significantly increased the plant height, tiller number and leaf number of L. perenne, and the application of 2.25 g DMP per pot significantly increased the plant height, branching number and leaf number of T. repens, while 4.50 g·pot^-1 of DMP significantly increased the total chlorophyll content, crude protein content and crude fat content of L. perenne, and this concentration of DMP addition also significantly increased the total chlorophyll and crude protein contents of T. repens. (2) DMP addition can increase the biomass of L. perenne and T. repens. Under potting conditions, DMP application significantly increased aboveground fresh and dry mass of L. perenneand T. repens compared with compound fertilizer treatment. DMP at 225 kg·hm^-2 also increased aboveground and belowground dry mass accumulation of L. perenneand T. repensunder low temperature and low sunlight field conditions in Zhaotong. (3) Transcriptome sequencing showed that DMP treatment induced the expression of genes related to phytohormone biosynthesis and signal transduction pathways in L. perenne, confirming that DMP promotes forage growth by inducing hormone biosynthesis and signal transduction pathways. This study first demonstrates that DMP can promote the growth of forage, and proposes a new strategy of using DMP as a growth promoter, which provides new ideas for the restoration and sustainable development of degraded grasslands under low temperature and low sunlight conditions.

Aims Plateau pika (Ochotona curzoniae) is a dominant small herbivorous mammal on the Qingzang Plateau, which affects the grassland ecosystem function through feeding, digging and excreting. Eimeriaspp., as the main intestinal parasite of plateau pika, has relatively high species specificity and is a potential new model for population control of plateau pika. However, it is still unclear about the change of plant communities in alpine grassland after control of plateau pika by Eimeriaspp.

Methods In this study, the grassland after control of plateau pika by Eimeria spp. and the control grassland were selected, and the plant diversity and network stability of alpine grassland after different treatments were analyzed to explore the effects of control of plateau pika by Eimeriaspp. on the plant community structure of grassland.

Important findings After field placement of Eimeriaspp., the active burrow entrance of plateau pika decreased significantly. After Eimeriaspp. treatment, grassland total coverage, Shannon-Wiener index, Simpson index and β diversity index increased significantly. The results of the mixed-effects model showed that Eimeriaspp. treatment had a greater impact on the Simpson index and Pielou evenness index. Increased inter-community correlations and average connectivity and stability in co-occurrence network analyses of plant communities after control of plateau pika by Eimeriaspp., and grassland keystone species changed from forbs to gramineae and cyperaceae. The results of this study provide new insights for biodiversity conservation, glires control, and ecosystem adaptive management of alpine grassland on the Qingzang Plateau.

Aims The grassland dominated by Leymus chinensisis one of the most important grassland types in northern China, providing important ecosystem service functions. However, due to long-term irrational utilization, the nutrients in the ecosystem stay in a state where outputs exceed inputs, leading to widespread degradation of the current Leymus chinensis grassland. The degradation affects its ecological and production functions. Previous studies have shown that the coupling of livestock and poultry can promote the restoration of degraded grasslands. This study aims to clarify the impacts of the coupling of livestock and poultry on L. chinensis at the individual, population and community scales.

Methods This study compared the differences in the individual traits, population and community characteristics of L. chinensis in livestock and poultry coupled plots (LP), grass mowing plots (GM), and traditional cattle and sheep grazing plots (CS).

Important findings The results showed that the soil NO- 3-N content in LP was 2.5 to 3 times higher than in GM and CS, and the soil available phosphorus content was more than 2 times that of GM and more than 6 times that of CS. The increase in soil nutrients content significantly improved the individual traits and population characteristics of L. chinensis. The chlorophyll content, specific leaf area, nitrogen content and phosphorus content of L. chinensis leaves in LP were significantly higher than those in GM and CS. The important values of the L. chinensis population in LP significantly increased by 29.7% and 173.2% compared to GM and CS in the first year, respectively. The leaf area index of L. chinensis population in LP reached above 3.4, while GM remained around 1.0 and CS remained around 0.2. The aboveground biomass of L. chinensis population in LP increased to (431.5 ± 45.3) g·m^-2 in the second year, which was 1.6 times that of GM and 9 times that of CS. The development of the L. chinensis population promoted positive communities’ succession, with plant cover in LP reaching over 90%, significantly higher than GM (around 60%) and CS (approximately 40%). The aboveground biomass of the plant community in LP increased to (597.6 ± 61.3) g·m^-2 in the second year, close to twice that of GM and 3 times that of CS. Under the utilization of coupling livestock and poultry, chickens fertilize the degraded grassland with manure during the plant growing seasons, which promotes the individual growth and development of L. chinensis, thereby increasing the important value of the L. chinensis population, as well as enhancing plant community coverage and aboveground biomass, ultimately leading the degraded L. chinensis grasslands toward near-natural recovery.