The emergy of metabolism in different ecosystems under the same environmental conditions in the agro-pastoral ecotone of northern China

Zhai, Xiajie; Huang, Ding; Tang, Shiming; Li, Shuiyan; Guo, Jianxin; Yang, Yuhui; Liu, Hongfei; Li, Jinsheng; Wang, Kun

doi:10.1016/j.ecolind.2016.11.028

Cited by 31 publications

(14 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Typical of arid and semi-arid regions globally, land cover in EANC varies between forest, grassland and barren land with sparse vegetation (Cao et al, 2015). Over recent decades, grassland degradation has been very serious due to the economic interests closely associated with the excessive consumption of grassland resources (Zhai et al, 2017). The region also has a variety of soil types, including chestnut, aeolian sandy, and gray-brown desert, and most are vulnerable to wind erosion.…”

Section: Study Sitesmentioning

confidence: 99%

Impact of near-surface wind speed variability on wind erosion in the eastern agro-pastoral transitional zone of Northern China, 1982–2016

Zhang

Azorín-Molina

Shi

et al. 2019

Agricultural and Forest Meteorology

View full text Add to dashboard Cite

Wind erosion in arid and semi-arid areas is an important global environmental issue, and changes in wind speed trends over time play a key role in wind erosion dynamics. In a warming climate, scientists have recently observed a widespread decline in wind speed, termed "stilling". Here, we apply the Revised Wind Erosion Equation Model (RWEQ) to simulate the variability of wind erosion and quantify the impact of wind speed changes on soil degradation dynamics over the eastern agro-pastoral transitional zone of Northern China from 1982 to 2016. Our results show that a significant (i.e., p<0.05) decrease (-0.007 m s-1 year-1) of near-surface wind speed was observed annually, with significant declining trends in spring (-0.010 m s-1 year-1)and autumn (-0.009 m s-1 year-1). At the same time, wind erosion simulations reveal a negative trend for the annual soil loss from wind erosion (-6.20 t hectare-2 year-1 , p<0.05; affecting 99.8% of the study region), with significant declining trends in all seasons, particularly in spring (-3.49 t hectare-2 year-1) and autumn (-1.26 hectare-2 year-1). Further, we isolate the effects of wind variability on wind erosion from 1982 to 2016 by the model variable control method. This shows that wind speed variability strongly weakens wind erosion at-8.14 t hectare-2 year-1 (p<0.05) annually, with the strongest stilling recorded in spring leading to major decreases of wind erosion in spring (-4.77 t hectare-2 year-1 , p<0.05). Meanwhile, the weakest stilling in summer had the opposite influence on wind erosion (+0.40 t hectare-2 year-1 , p<0.10). To summarize, our findings have shown a significant impact of wind stilling on the decline of soil erosion rates in Northern China.

show abstract

Section: Study Sitesmentioning

confidence: 99%

Impact of near-surface wind speed variability on wind erosion in the eastern agro-pastoral transitional zone of Northern China, 1982–2016

Zhang

Azorín-Molina

Shi

et al. 2019

Agricultural and Forest Meteorology

View full text Add to dashboard Cite

show abstract

“…The final step is calculation of emergy-based indices used to assess various aspects of performance, such as resource use efficiency, environmental impact, system sustainability. Just as other studies on the sustainability of agricultural systems [35][36][37], emergy-power density (EPD), emergy self-sufficiency ratio (ESR), emergy yield ratio (EYR), environmental loading ratio (ELR), emergy restoration ratio (ERR), emergy benefit ratio (EBR) and emergy sustainability index (ESI) were used for balanced emergy analysis ( Table 2, Table A1).…”

Section: Emergy Analysismentioning

confidence: 99%

Emergy and Economic Evaluation of Seven Typical Agroforestry Planting Patterns in the Karst Region of Southwest China

Zou

Zeng

Wang

et al. 2019

Forests

View full text Add to dashboard Cite

As a vast degraded land ecosystem, the karst region of southwest China is currently experiencing serious conflicts between restoration of degraded vegetation communities and agricultural activities. Furthermore, it is not clear what land use pattern suits local farmers best. To evaluate the sustainability of the degraded agricultural ecosystems in the region, methods for emergy analysis were used to compare the ecological and economic benefits from seven typical agroforestry planting patterns in the Yunnan province. The eco-efficiencies of the apple pattern (AP), pear pattern (PP), pomegranate pattern (PRP) were all lower than that of the traditional corn pattern (CP), although the economic benefit was higher than that of CP. Ecological benefits of the apple-soybean pattern (ASP) and the pear-pumpkin pattern (PPP) were not significantly improved, while ecological and economic benefits of the pomegranate-grass-sheep pattern (PGSP) was improved significantly. Intercropping pumpkin in PP increased the economic efficiency by 28.3%, which was superior to that of the intercropping of soybeans (4.6%) in AP. These data implied that interplanting crops in AP and PP might result in higher economic benefit than the existing interplanting pattern. The multistory agroforestry planting pattern and raising in PGSP could optimize the relationship among tree-grass-sheep and improve ecological and economic benefits. Additionally, scenario analysis showed that local farmers might enjoy better ecological and economic benefits at a large scale by optimizing current agricultural production patterns. Our results suggest that together, both the local government and farmers can adjust the structure of agroforestry ecosystems to foster the sustainable development of the ecological industry in the karst region of China.

show abstract

“…Briefly, emergy inputs for crop production system can be classified into four types: (1) local renewable resources (R), such as sunlight, rain, wind, earth circle, and atmospheric nitrogen deposition; (2) local nonrenewable resources (N), which we considered as soil degradation (Lefroy and Rydberg, 2003;Zhang et al, 2007), i.e. net loss of SOM; (3) purchased nonrenewable resources (F N ), such as mineral fertilizers, chemicals (herbicides and inoculant), machinery and diesel use; (4) purchased renewable resources (F R ), which we considered as labor and seeds (Ma et al, 2015;Zhai et al, 2017;Zhang et al, 2016). The net loss of SOC during the study period was counted as local nonrenewable resources (N), while the net increase in SOC was counted as a co-product with the output of grain yield.…”

Section: Emergy Analysismentioning

confidence: 99%

Emergy and energy analysis as an integrative indicator of sustainability: A case study in semi-arid Canadian farmlands

Fan

McConkey

Janzen

et al. 2018

Journal of Cleaner Production

View full text Add to dashboard Cite

Agricultural is essential to feed the human world but it can also degrade the physical world. Therefore, we need widely-accepted metrics to assess how prospective practices influence sustainability. We hypothesized that emergy and energy analyses considered together provide a robust, comprehensive measure of sustainability, and evaluated this hypothesis using findings from two field studies in the semiarid prairie region of Canada: a systems experiment including nine different 3-yr cropping rotation systems and a stubble experiment involving five preceding crop stubbles treatments with three nitrogen (N) addition levels. The grain yield emergy transformities of rotation systems with pulses, ranging from 0.68 to 0.83 Eþ05 sej J À1 , were 32% lower (P < 0.05) than rotations without pulses. Significantly lower grain transformity of durum wheat grown on pulse stubbles than grown on durum wheat stubble were observed for both the systems and stubble experiments, suggested a higher crop production efficiency conferred by previous pulse crops. The emergy sustainability index (ESI) of Fallow-Durum wheat-Pea (F-D-P) rotation (1.94) was 1.3e2.2 times that of other rotations, while the continuous rotations increased ESI from 1.00e1.11 to ESI DQ of 2.00e2.21 by considering the storage increase (DQ) of the system, i.e. soil organic carbon (SOC). The grain yield/energy input ratio (G/I) and energy output/energy input ratio (O/I) for F-D-P rotation (775 g MJ À1 and 12.9, respectively) were significantly (P < 0.05) higher than those of all other rotations for its low energy input, which was obtained at the cost of huge SOC decrease. Modified energy use efficiency indices, G/I DSOC and O/I DSOC , were proposed in the present study to include the effect of SOC change (DSOC) in energy use efficiency by regarding DSOC as energy input where the system depleted SOC and as energy output where SOC accumulated. The G/I DSOC and O/I DSOC ratios for continuous rotations were significantly (P < 0.05) higher than those of other rotations, indicating higher energy use efficiency in continuous rotation systems. Therefore, ESI DQ and O/I DSOC are recommended as sustainability indicators in emergy and energy analysis respectively, and we recommend that emergy and energy analysis should be done and considered together to have a more informative assessment of relative sustainability and efficiency of cropping systems.

show abstract

The emergy of metabolism in different ecosystems under the same environmental conditions in the agro-pastoral ecotone of northern China

Cited by 31 publications

References 40 publications

Impact of near-surface wind speed variability on wind erosion in the eastern agro-pastoral transitional zone of Northern China, 1982–2016

Impact of near-surface wind speed variability on wind erosion in the eastern agro-pastoral transitional zone of Northern China, 1982–2016

Emergy and Economic Evaluation of Seven Typical Agroforestry Planting Patterns in the Karst Region of Southwest China

Emergy and energy analysis as an integrative indicator of sustainability: A case study in semi-arid Canadian farmlands

Contact Info

Product

Resources

About