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1

Effects of land use/cover change in the desert oasis system on topsoil carbon and nitrogen (middle of Heihe River basin, China)

100%

Niu R.-X. , Zhao X.-Y. , Liu J.-L. , Qin Y.

Polish Journal of Ecology

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2013

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tom Vol. 61, nr 1

45--54

EN

Land use/cover change (LUCC) is one of the main factors that influence the terrestrial carbon (C) and nitrogen (N) cycle. We examined the effects of land use/cover change on topsoil C, N, and microbial biomass C, N (MBC, MBN) and their relationship with other soil properties in the middle of Heihe river basin along a land use change gradient of 100-year farmland, 27-year farmland, 33-year pine forest, 28-year poplar forest, and 21-year shrubland, as well as native desert from which all the above cultivated systems are converted. Results revealed that land use conversion from native desert to the above cultivated ecosystems not only changed the basic eco-hydrological factors of the soil, such as improving the soil moisture and field capacity, decreasing the pH and salinity, but also altered the nutrient factors, such as improving the concentrations of soil organic C (SOC), total N (TN), MBC, MBN, NO3--N and NH4+-N,. With the increase of cultivated years, land use conversion had an increasing impact on the C and N sequestration and soil nutrients stabilization.

2

Influence of grazing exclusion on soil macro-invertebrate diversity in degraded sandy grassland (Inner Mongolia, China)

100%

Liu R.-T. , Zhao H.-L. , Zhao X.-Y.

Polish Journal of Ecology

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2012

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tom 60

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nr 2

EN

In arid and semi-arid areas, heavy grazing combined with climate change cause land degradation (e.g., desertification). Grazing management is essential for ecosystem recovery and desertification control in these areas, including Northern China’s Horqin Sandy Land. However, the recovery of soil faunal community during grazing exclusion is unknown. We examined plant and soil macro-invertebrate community structure together with soil properties in three treatments in a representative degraded Horqin sandy grassland: exclosure for 15 and 10 years (15EX and 10EX) and long-term continuous grazing (CG). The vegetation cover and height increased significantly and soil bulk density decreased significantly along the gradient from CG to 15EX, but there were no significant differences in soil pH, electrical conductivity, organic carbon and total nitrogen. Soil macro-invertebrate abundance, group richness and diversity increased along the gradient from CG to 15EX, with significant differences in invertebrate abundance and group richness between CG and 15EX; there was no significant differences between CG and 10EX. There were no significant differences in soil macro- invertebrate diversity and evenness between these three treatments. These results suggested that grazing exclusion for at least 15 years might be necessary for the recovery of these fauna. The vegetation height and the soil electrical conductivity, organic carbon, and total nitrogen determined the distribution and community structure of soil macro-invertebrates. Some faunal groups lived in specific habitats due to strong adaptation to different management practices. For example, the Thomisidae, Philodromidae, Salticidae, and Rhopalidae tended to live in habitats with tall vegetation. The Lygaeidae, Miridae, Teneberionidae, and Linyphiidae adapted to live in soil with low soil organic carbon and nitrogen (ungrazed grassland).

3

H2 and syngas production from catalytic cracking of pig manure and compost pyrolysis vapor over Ni-based catalysts

100%

Li W. , Ren J. , Zhao X.-Y. , Takarada T.

Polish Journal of Chemical Technology

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2018

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tom Vol. 20, nr 3

8--14

EN

Catalytic cracking of volatiles derived from wet pig manure (WPM), dried pig manure and their compost was investigated over Ni/Al2O3 and Ni-loaded on lignite char (Ni/C). Non-catalytic pyrolysis of WPM resulted in a carbon conversion of 43.3% and 18.5% in heavy tar and light tar, respectively. No tar was formed when Ni/Al2O3 was introduced for WPM gasification and the gas yield significantly reached to a high value of 64.4 mmol/g at 650°C. When Ni/C was employed, 5.9% of carbon in the light tar was found at 650°C, revealing that the Ni/C is not active enough for cracking of tarry materials. The pyrolysis vapor was cracked completely and gave a H2-rich tar free syngas in high yield. High water amount of WPM promotes steam gasification of char support, causing the deactivation of Ni/C. Such a study may be beneficial to the development of livestock manure catalytic gasification technology.

4

Effects of land use-cover change in the desert oasis system on topsoil carbon and nitrogen (middle of Heihe River basin, China)

100%

Niu R.-X. , Zhao X.-Y. , Liu J.-L. , Qin Y.

Polish Journal of Ecology

|

2013

|

tom 61

|

nr 1

EN

Land use/cover change (LUCC) is one of the main factors that influence the terrestrial carbon (C) and nitrogen (N) cycle. We examined the effects of land use/cover change on topsoil C, N, and microbial biomass C, N (MBC, MBN) and their relationship with other soil properties in the middle of Heihe river basin along a land use change gradient of 100-year farmland, 27-year farmland, 33-year pine forest, 28-year poplar forest, and 21-year shrubland, as well as native desert from which all the above cultivated systems are converted. Results revealed that land use conversion from native desert to the above cultivated ecosystems not only changed the basic eco-hydrological factors of the soil, such as improving the soil moisture and field capacity, decreasing the pH and salinity, but also altered the nutrient factors, such as improving the concentrations of soil organic C (SOC), total N (TN), MBC, MBN, NO₃⁻ -N and NH₄⁺ -N,. With the increase of cultivated years, land use conversion had an increasing impact on the C and N sequestration and soil nutrients stabilization.

5

Variations of Leaf Economic Spectrum of Eight Dominant Plant Species in Two Successional Stages Under Contrasting Nutrient Supply

88%

Mao W. , Li Y.-L. , Zhao X.-Y. , Zhang T.-H. , Liu X.-P.

Polish Journal of Ecology

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2016

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tom Vol. 64, nr 1

14--24

EN

Leaf functional traits are indicators of both plant community and ecosystem responses to environmental factors and can thus increase our capacity to understand ecosystem processes and community assembly due to climate change. The variation in leaf functional traits between succession stages in Horqin Sandy Land is caused by soil nutrient content and by intrinsic biological characteristic of species, but the effects are different. Leaf economic spectra were assessed for seven leaf traits of eight species from early and advanced stages of succession. Species from early succession stages are Agriophyllum squarrosum (L.) Moq., Corispermum macrocarpum Bge., Setaria viridis (L.) Beauv. and Pennisetum centrasiaticum Tzvel., and species from advanced successional stages are Chenopodium acuminatum Willd., Chloris virgate Swartz, Digitaria sanguinalis (L.) Scop. and Leymus secalinus (Georgi) Tzvel. All these species were grown in a greenhouse experiment under two contrasting nutrient supplies including high nutrient level (N+, with 20 g of nutrient addition) and low nutrient level (N-, with no added nutrients). As expected, the resource uptake strategies of the species were affected by soil fertilization addition. Leaf nitrogen content (LNC), leaf phosphorus content (LPC), and photosynthetic capacity per unit leaf area (Aarea) significantly increased at high nutrient level but LPC is more dramatically changed than others leaf traits. Leaf life span (LLS) and specific leaf area (SLA) did not show similar tendency with succession stage. At the same nutrient level, LES still shows different pattern between the early and the advanced succession stages. Species from early succession stages have higher LPC and Aarea, compared to species from advanced stages. Species from early succession stage also tend to have higher SLA and higher LNC than at the advanced succession stage. The LLS did not show any clear changes with succession process. These results provide evidence that LES shift along the succession process is mainly caused by intrinsic biological characteristic of species.

6

Variations of leaf economic spectrum of eight dominant plant species in two successional stages under contrasting nutrient supply

88%

Mao W. , Li Y.-L. , Zhao X.-Y. , Zhang T.-H. , Liu X.-P.

Polish Journal of Ecology

|

2016

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tom 64

|

nr 1

EN

Leaf functional traits are indicators of both plant community and ecosystem responses to environmental factors and can thus increase our capacity to understand ecosystem processes and community assembly due to climate change. The variation in leaf functional traits between succession stages in Horqin Sandy Land is caused by soil nutrient content and by intrinsic biological characteristic of species, but the effects are different. Leaf economic spectra were assessed for seven leaf traits of eight species from early and advanced stages of succession. Species from early succession stages are Agriophyllum squarrosum (L.) Moq., Corispermum macrocarpum Bge., Setaria viridis (L.) Beauv. and Pennisetum centrasiaticum Tzvel., and species from advanced successional stages are Chenopodium acuminatum Willd., Chloris virgate Swartz, Digitaria sanguinalis (L.) Scop. and Leymus secalinus (Georgi) Tzvel. All these species were grown in a greenhouse experiment under two contrasting nutrient supplies including high nutrient level (N , with 20 g of nutrient addition) and low nutrient level (N-, with no added nutrients). As expected, the resource uptake strategies of the species were affected by soil fertilization addition. Leaf nitrogen content (LNC), leaf phosphorus content (LPC), and photosynthetic capacity per unit leaf area (Aarea) significantly increased at high nutrient level but LPC is more dramatically changed than others leaf traits. Leaf life span (LLS) and specific leaf area (SLA) did not show similar tendency with succession stage. At the same nutrient level, LES still shows different pattern between the early and the advanced succession stages. Species from early succession stages have higher LPC and Aarea, compared to species from advanced stages. Species from early succession stage also tend to have higher SLA and higher LNC than at the advanced succession stage. The LLS did not show any clear changes with succession process. These results provide evidence that LES shift along the succession process is mainly caused by intrinsic biological characteristic of species.

7

Genetic diversity in Salix gordejevii populations from different environmental gradients in Horqin Sandy Land, Northern China

75%

Huang W.-D. , Zhao X.-Y. , Zhao X. , Luo Y.-Y. , Feng J. , Su N. , He Y.-Z.

Polish Journal of Ecology

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2019

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tom 67

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nr 3

8

Life history strategy influences biomass allocation in response to limiting nutrients and water in an arid system

75%

Mao W. , Allington G. , Li Y.-L. , Zhang T.-H. , Zhao X.-Y. , Wang S.-K.

Polish Journal of Ecology

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2012

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tom 60

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nr 3

EN

The optimal partitioning theory (OPT) predicts that a plant should allocate relatively more biomass to the organs that acquire the most limiting resource. However, variation in biomass allocation among plant parts can also occur as a plant grows in size. As an alternative approach, allometric biomass partitioning theory (APT) asserts that plants should trade off their biomass between roots, stems and leaves, and this approach can minimize bias when comparing biomass allocation patterns by accounting for plant size in the analysis. We analyzed the biomass allocation strategy of the two species: annual Setaria viridis (L.) Beauv and perennial Pennisetum centrasiaticum Tzvel from the Horqin Sandy Land of northern China by treating them with different availabilities of soil nutrient and water (added in summer and winter), and hypothesized that the two species have different patterns of biomass allocation strategy in response to different soil water content and soil nitrogen content. After taking plant size into account, the biomass allocation strategy of S. viridis and P. centrasiaticum differed in response to nitrogen and water; leaves and root:shoot ratio (RTS) of S. viridis were “true” in response to various soil nitrogen contents. The plasticity of roots was also “true” in response to fluctuation in soil water content. However, P. centrasiaticum showed a different pattern with no shift of biomass allocation strategy in response to nitrogen and water. Adjustment in organs biomass allocation pattern of S. viridis in response to nitrogen and water limitation was dramatic, this suggested that S. viridis support optimal partitioning theory (OPT). P. centrasiaticum has better tolerance to varied environments and more likely support the allometric biomass partitioning theory (APT), this characteristic may allow P. centrasiaticum to keep dominance in fragile habitats.