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1

Biodiversity Versus stability: the biological effect of plant functional traits on ecosystem functioning in grasslands dominated by Leymus chinensis

100%
Zhao N., Shao X., Wang K.
Polish Journal of Ecology
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2016
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tom 64
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nr 3
Although diversity-ecosystem theory predicts that ecosystem functioning is strongly determined by species number, species traits play an important role in regulating ecosystem-level dynamics. We analyze responses of species attributes to diversity level and resource availability, and explore their consequences for ecosystem functioning and ultimately assess the contributions of five traits (vegetative plant height, clonal growth, root depth, cespitose habit and seed mass) to ecosystem functioning defined by spatial stability of community biomass. We found that functional traits disproportionately affected spatial stability. Relationships between species functional traits and spatial stability of community biomass indicated that diversity of vegetative plant height facilitated stability of a nitrogen fertilized undisturbed natural community (NAT), and that of a phosphorus fertilized forb, legume and bunchgrass community (FLB). The clonal growth form was also identified as a stabilizing trigger for a unfertilized undisturbed natural community (NAT), whereas diversity in root depth, cespitose habit and seed mass were related to destabilization of a nitrogen fertilized rhizomatous grass community (RRR). Studies quantifying interactions among plant traits, community structure and ecological functioning will contribute much more to understanding of the effects of the ecological behavior of specific traits on the ecosystem functioning.
2

Field experiments on reducing pollutants in agricultural-drained water using soil-vegetation buffer strips

100%
Li Y., Shao X., Sheng Z.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 1
Agricultural drainage is one of the leading contributors to agricultural non-point source (AGNPS) pollution in China. It is difficult to treat due to its dispersed nature. In recent years, although agricultural drainage water has been reused in agricultural production, its poor quality has limited its potential utilization. To optimize its reuse, we designed and tested a treatment system for agricultural-drained water compromising a vegetation buffer, slopes (plant filter), a water collection area, and a soil-retention wall in Hengxi town, Nanjing, Jiangsu Province, China. By exploiting the soil-vegetation buffer strips, nitrogen and phosphorus in the paddy field’s surface drainage are expected to be reduced dramatically. Test results suggest that after applying basal fertilizer, the removal rates of total nitrogen by the soil-vegetation buffer strips are 90.6% and 95.2% for controlled and conventional irrigation-drainage treatments, respectively. In addition, the removal rates of dissolved nitrogen are 92% and 90.7% (controlled and conventional), the removal rates of total phosphorus are 94.2% and 92.9%, and for dissolved phosphorus, the rates are 94.4% and 95%, respectively. These data indicate that drainage water from a paddy field that has been treated through the constructed system could reach the standard of National Class II with two irrigation-drainage methods, while for control treatments water quality can only reach Class V, which is severely contaminated. With this system, the reuse of agricultural water resources could be achieved, which will undoubtedly provide a great potential for agricultural water management in southern China, as well as achieving excellent overall ecological benefits.
3

Water conservation and nitrogen loading reduction effects with controlled and mid-gathering irrigation in a paddy field

88%
Li Y., Shao X., Sheng Z., Guan W., Xiao M.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 3
Rice is a widely cultivated crop in China and needs a large quantity of water during its entire growth period. Many water-saving irrigation techniques have been developed and widely applied to conserve water in paddy fields in recent years. A controlled and mid-gathering irrigation (CMI) regime is one of them, of which the main feature is to maximize the use of rainwater different from the others. The objective of this study was to assess and verify the water conservation and nitrogen pollution reduction effects of CMI in comparison with a conventional irrigation (CVI) regime. Results showed that the CMI method had potential for water conservation by reducing total irrigation amount and irrigation frequency and making better utilization of rainwater during the rice growth stage. By making use of irrigation water more efficiently, CMI showed higher irrigation water use efficiency and rainfall use efficiency. CMI can also reduce nitrogen pollution emitted to the water system by reducing the pollutant discharge rather than the pollutant concentration during a storm event. However, the irrigation regime’s effect on pollutant loading reduction was not as significant as fertilizer according to experiment results. Thus, the controlled and mid-gathering irrigation regime was favorable for water conservation and reducing emissions of non-point source pollution.
4

Thallium, Arsenic, and Mercury contamination of soil near the world’s largest and longest- operating tungsten mine

88%
Cheng H., Duan X., Liu S., Lin C., Shao X.
Polish Journal of Environmental Studies
|
2013
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tom 22
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nr 1
Little is known about soil thallium contamination near tungsten (W) mines. This study investigated thallium, arsenic, and mercury contents and enrichment in agricultural soils near the world’s largest and longestoperating W mine in China. Results show that the long-term W mining significantly elevated Tl from 0.77 to 1.61 mg·kg⁻¹ and As from 7.54 to 22.64 mg·kg⁻¹, with enrichment factors of 2.0 (1.4 to 3.7) and 2.9 (1.5 to 7.2), respectively. Hg contents were similar at the contaminated site (0.16 mg·kg⁻¹) and control site (0.19 mg·kg⁻¹), but were two to three times higher than the soil background content of Jianxi province. Thus, Hg contamination in the soil probably was mainly caused by coal and petrol burning instead of W mining.
5

Nitrogen-decreasing and yield-increasing effects of combined applications of organic and inorganic fertilizers under controlled irrigation in a paddy field

76%
Li Y., Shao X., Guan W., Ren L., Liu J., Wang J., Wu Q.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 2
Inadequate fertilization may result in water pollution and nutrient leaching, especially in paddy fi elds. It is expected that the combination of organic and inorganic fertilizers reduces water pollution in addition to crop yield improvement. In this study, combined fertilization with organic and inorganic fertilizers was tested under controlled irrigation conditions. With the addition of organic fertilizer, the pH of paddy soil could be maintained in a rather neutral environment, and the soil organic matter concentration could increase – especially under a controlled irrigation regime. Hydrolyzed nitrogen was noticed in the fertilized plots with an increasing trend compared to unfertilized plots. However, available phosphorus concentration decreased in all treatments after rice harvest. During the drainage process, the ammonium nitrogen was the main form of nitrogen loss. Organic fertilizer application signifi cantly improved productive panicles and thus increased paddy yield. We concluded that with the combination of organic-inorganic fertilizer application and controlled irrigation, the pollutants can be removed to some extent and the rice yield can be increased signifi cantly, which is favorable for environmental protection and yield promotion.
6

Nutrient uptake and allocation by plants in recent mounds created by subterranean rodent, plateau zokor Eospalax baileyi

76%
Wu R., Wei X., Liu K., Zhong M., Liu Y., Pan D., Shao X.
Polish Journal of Ecology
|
2017
|
tom 65
|
nr 1
To understand the nutrient absorption and adaptability of plant species that initially colonize mounds and the influences of the plateau zokor on the diversity of the plant community after 4 years' period, a series of experiments was conducted in an alpine meadow on the Qinghai-Tibetan Plateau. The contents of C and N and the flow of N in pioneer species were measured and tracked using the ¹⁵N isotope tracer method, and the species diversity on 4-year-old mounds was investigated. The results showed that (1) plateau zokors could influence the plant species on the mounds by creating gaps in the grassland; (2) Elymus nutans and Elsholtzia feddei, with high rates and efficiencies of nutrient absorption and transportation, were more competitive on the newly formed mounds than other species; (3) Elymus nutans played a dominant role in the plant community of the mounds; and (4) plateau zokors did not change the plant diversity after 4 years' period. These findings indicated that species colonizing the mounds experienced a process of competition when gaps were created by the rodents, that species with greater capabilities for resource acquisition and utilization had stronger competitiveness and vice versa, and that after a few years, the plant diversity on the mounds was almost similar to that of the undisturbed grassland.
7

Leaf morphology shift of three dominant species along altitudinal gradient in an Alpine meadow of the Quinghai - Tibetan Plateau

64%
Zhong M., Wang J., Liu K., Wu R., Liu Y., Wei X., Pan D., Shao X.
Polish Journal of Ecology
|
2014
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tom 62
|
nr 4
It has been observed that leaf morphology shift within species is linked to climate change, but there are few studies on the effects of altitude change on leaf morphology of species. We hypothesized that similar to climate change, a morphological shift within species would occur over time under different growing altitudes. In this study, we evaluated three dominant grass species: Elymus nutans Griseb., Kobresia capillifolia Clarke., Carex moorcroftii Boott., taking advantage of the altitudinal variations (3000-4000 a.s.l.) on the Qinghai-Tibetan Plateau. Our study showed that almost all leaf traits of these three species had significant differences (P <0.05) across an altitudinal gradient. Different species responded differently to altitude change. Leaf thickness (LT) of the three species increased with increase in altitude. Leaf area (LA) of E. nutans and C. moorcroftii decreased with increasing altitude, but that of K. capillifolia increased. There was no obvious linear effect on leaf dry matter content (LDMC) and specific leaf area (SLA) of these three species. LDMC of E. nutans and C. moorcroftii showed a trend of increase, while that of K. capillifolia decreased. SLA of E. nutans and K. capillifolia showed a trend of increase, but that of C. moorcroftii decreased with increase in altitude. In addition, soil pH (pH) and air temperature (AT) decreased with increase in altitude. However, other soil and climate factors increased as altitude increased. The finding of this work is that leaf morphology shift within species happens under altitude change to adapt to specific environment.
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