Physiological responses of Agriophyllum squarrosum and Setaria viridis to drought and re-watering.

Drought resistance of psammophyte determines survival and growth, but their responses to drought are not well understood. We conducted a pot experiment to study how physiological characteristics respond to drought and rehydration. We found that watering to 60-65% of field capacity (the control) provided more water than was required by Agriophyllum squarrosum and its leaves became yellow and slightly wilted.

Effect of Root and Mycelia on Fine Root Decomposition and Release of Carbon and Nitrogen Under in a Semi-arid Sandy Grassland in China.

Plant fine root turnover is a continuous process both spatially and temporally, and fine root decomposition is affected by many biotic and abiotic factors. However, the effect of the living roots and the associated mycorrhizal fungal mycelia on fine root decomposition remains unclear. The objective of this study is to explore the influence of these biotic factors on fine root decomposition in a semi-arid ecosystem.

Variation in Soil Microbial Communities Along an Elevational Gradient in Alpine Meadows of the Qilian Mountains, China.

Bacterial, archaeal, and eukaryota diversity in mountainous areas varies along elevational gradients, but details remain unclear. Here, we use a next-generation sequencing method based on 16S/18S rRNA to reveal the soil microbial diversity and community compositions of alpine meadow ecosystems along an elevation span of nearly 2,000 m (1,936-3,896 m) in China's Qilian Mountains. Both bacterial and eukaryota diversity increased linearly with increasing elevation, whereas archaeal diversity increased, but not significantly.

Effects of Nitrogen Addition and Reproductive Effort on Nutrient Resorption of a Sand-Fixing Shrub.

is a sand-fixing leguminous shrub with strong resistance to drought, cold, and low soil fertility. As a result, it plays an essential role in combating desertification in northern China, but little is known about its nutrient budget. Nutrient resorption is a key process in plant nutrient conservation and has marked ecological implications for plant fitness and ecosystem nutrient cycling.

Photosynthesis and Growth of (C) is Superior to (C) During Drought and Recovery.

Global warming and changes in rainfall patterns may put many ecosystems at risk of drought. These stressors could be particularly destructive in arid systems where species are already water-limited. Understanding plant responses in terms of photosynthesis and growth to drought and rewatering is essential for predicting ecosystem-level responses to climate change.

Litters Have Strong Negative Allelopathic Effects on Earlier Successional Plants in a Semi-Arid Sandy Dune Region in China.

Turcz. ex Besser occurs following the appearance of a pioneer species, (L.) Moq.

Growth and Physiology of Two Psammophytes to Precipitation Manipulation in Horqin Sandy Land, Eastern China.

The availability of water is the critical factor driving plant growth, physiological responses, population and community succession in arid and semiarid regions, thus a precipitation addition-reduction platform with five experimental treatments, was established to explore the growth and physiology of two psammophytes (also known as psammophiles) to precipitation manipulation in Horqin Sandy Land. Changes in coverage and density were measured, and antioxidant enzymes and osmoregulatory substances in both of the studied species were determined. Investigation results showed that the average vegetation coverage increased with an increasing precipitation, and reached a maximum in July.

Temporal and spatial variation of extreme temperatures in an agro-pastoral ecotone of northern China from 1960 to 2016.

The agro-pastoral ecotone of northern China is one of the areas most sensitive to global temperature change. To analyze the temporal and spatial trends of extreme temperature events in this area, we calculated the values of 16 extreme-temperature indices from 1960 to 2016 based on data from 45 national meteorological stations. We found that the coldest-temperature indices decreased significantly and the warmest-temperature indices increased significantly.

Spatial pattern of soil organic carbon and total nitrogen, and analysis of related factors in an agro-pastoral zone in Northern China.

The spatial pattern of soil organic carbon (SOC) and total nitrogen (TN) densities plays a profound important role in estimating carbon and nitrogen budgets. Naiman Banner located in northern China was chosen as research site, a total of 332 soil samples were taken in a depth of 100 cm from the low hilly land in the southern part, sandy land in the middle part and an alluvial plain in the northern part of the county. The results showed that SOC and TN density initially decreased and then increased from the north to the south, The highest densities, were generally in the south, with the lowest generally in the middle part.

Dominant plant species shape soil bacterial community in semiarid sandy land of northern China.

Plant species affect soil bacterial diversity and compositions. However, little is known about the role of dominant plant species in shaping the soil bacterial community during the restoration of sandy grasslands in Horqin Sandy Land, northern China. We established a mesocosm pots experiment to investigate short-term responses of soil bacterial diversity and composition, and the related soil properties in degraded soils without vegetation (bare sand as the control, CK) to restoration with five plant species that dominate across restoration stages: (AS), (AH), (SV), (CA), and (CM).

Effects of foliage litter of a pioneer shrub (Artemisia halodendron) on germination from the soil seedbank in a semi-arid sandy grassland in China.

Vegetation recovery during succession is an important process for ecological restoration of the soil, especially in degraded sandy land. However, the driving mechanisms, such as how a pioneer species competes with other species, is uncertain. In China's Horqin Sandy Land, Artemisia halodendron is an important shrub that is common on semi-fixed dunes, where it replaces Agriophyllum squarrosum during succession, and is an important indicator species of the second stage of dune stabilization.

Contrasting effects of plant inter- and intraspecific variation on community trait responses to restoration of a sandy grassland ecosystem.

Changes in plant community traits along an environmental gradient are caused by interspecific and intraspecific trait variation. However, little is known about the role of interspecific and intraspecific trait variation in plant community responses to the restoration of a sandy grassland ecosystem. We measured five functional traits of 34 species along a restoration gradient of sandy grassland (mobile dune, semi-fixed dune, fixed dune, and grassland) in Horqin Sand Land, northern China.

Responses of soil fungal community to the sandy grassland restoration in Horqin Sandy Land, northern China.

Sandy grassland restoration is a vital process including re-structure of soils, restoration of vegetation, and soil functioning in arid and semi-arid regions. Soil fungal community is a complex and critical component of soil functioning and ecological balance due to its roles in organic matter decomposition and nutrient cycling following sandy grassland restoration. In this study, soil fungal community and its relationship with environmental factors were examined along a habitat gradient of sandy grassland restoration: mobile dunes (MD), semi-fixed dunes (SFD), fixed dunes (FD), and grassland (G).

[Germination and seedling growth of Artemisia halodendron under different incubation environments].

Artemisia halodendron is a dominant species in mobile and semi-mobile dunes of Horqin Sand Land. To investigate the germination character and seedling growth under different temperature and light conditions, the germination rate, germination index and growth of radicle and plumule were measured after treatments in laboratory and heating cabinet incubations. In the laboratory the light and temperature were near to nature condition, while in the heating cabinet it was kept at 25 degrees C with varying durations of light supply, including 24-, 12- and 0-hour light per day.

[Ecological effect of plant root exudates and related affecting factors: a review].

The formation of plant root exudates is a vital physiological phenomenon in the metabolic processes of plant, and an important link of material turnover in "plant-soil" system. To study the plant root exudates is of significance in understanding the matter and energy flow, carbon and nitrogen balance, and improvement of primary production in terrestrial ecosystems. This paper reviewed the ecological effect of plant root exudates, such as the effect on plant physiological processes, soil microorganisms, soil matter turnover, and degradation of soil organic contaminants, and summarized the related affecting factors, including soil heavy metals and nutrient contents, soil moisture, light, and heat conditions, plant gene type, soil microorganisms, and input of exogenous organic contaminants.