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Soil erosion is prevalent in karst areas, but few studies have compared the differences in the drivers for soil microbial communities among karst ecosystems with different soil depths, and most studies have focused on the local scale. To fill this research gap, we investigated the upper 20 cm soil layers of 10 shallow–soil depth (shallow–SDC, total soil depth less than 100 cm) and 11 deep–soil depth communities (deep–SDC, total soil depth more than 100 cm), covering a broad range of vegetation types, soils, and climates. The microbial community characteristics of both the shallow–SDC and deep–SDC soils were tested by phospholipid fatty acid (PLFAs) analysis, and the key drivers of the microbial communities were illustrated by forward selection and variance partitioning analysis. Our findings demonstrated that more abundant soil nutrients supported higher fungal PLFA in shallow–SDC than in deep–SDC (p < 0.05). Furthermore, stronger correlation between the microbial community and the plant–soil system was found in shallow–SDC: the pure plant effect explained the 43.2% of variance in microbial biomass and 57.8% of the variance in the ratio of Gram–positive bacteria to Gram–negative bacteria (G+/G−), and the ratio of fungi to total bacteria (F/B); the pure soil effect accounted for 68.6% variance in the microbial diversity. The ratio of microbial PLFA cyclopropyl to precursors (Cy/Pr) and the ratio of saturated PLFA to monounsaturated PLFA (S/M) as indicators of microbial stress were controlled by pH, but high pH was not conducive to microorganisms in this area. Meanwhile, Cy/Pr in all communities was >0.1, indicating that microorganisms were under environmental stress. Therefore, the further ecological restoration of degraded karst communities is needed to improve their microbial communities.
Huiling Guan; Jiangwen Fan; Haiyan Zhang; Warwick Harris. Comparison of Drivers of Soil Microbial Communities Developed in Karst Ecosystems with Shallow and Deep Soil Depths. Agronomy 2021, 11, 173 .
AMA StyleHuiling Guan, Jiangwen Fan, Haiyan Zhang, Warwick Harris. Comparison of Drivers of Soil Microbial Communities Developed in Karst Ecosystems with Shallow and Deep Soil Depths. Agronomy. 2021; 11 (1):173.
Chicago/Turabian StyleHuiling Guan; Jiangwen Fan; Haiyan Zhang; Warwick Harris. 2021. "Comparison of Drivers of Soil Microbial Communities Developed in Karst Ecosystems with Shallow and Deep Soil Depths." Agronomy 11, no. 1: 173.
Soil quality assessment is important for karst ecosystems where soil erosion is significant. A large amount of vegetation restoration has been implemented since the early 21st century in degraded karst areas across southwestern China. However, the impacts on soil quality of different restoration types rarely have been compared systematically. In the current study, we investigated the soil quality after a number of vegetation restoration projects as well as their adjacent cropland by analyzing soil samples. Six vegetation restoration types were evaluated, including one natural restoration (natural shrubland, protected for 13 years), three economic forests (4 years Eucalyptus robusta, 4 years Prunus salicina and 6 years Zenia insignis) and two mixed forests (1 year Juglans regia–crop and 13 years Toona sinensis-Pennisetum purpureum ). We evaluated the benefits of different restoration types more accurately by setting each adjacent cropland as the control and setting the variation between the corresponding restored and control site as the evaluation object so that the background differences of six sites could be eliminated. The results indicated that natural shrubland, Toona sinensis-Pennisetum purpureum and Zenia insignis were effective in improving soil quality index (SQI) in degraded karst cropland largely due to their higher SOC and TN content. The variation of SQI (VSQI) of natural shrubland was significantly higher than that in Eucalyptus robusta, Prunus salicina and Juglans regia-crop in total soil layer (0–30 cm) (P < 0.05), indicating natural shrubland had better capacity to improve soil quality. The boosting regression tree model revealed that vegetation restoration type explained 73.49% and restoration time explained 10.30% of the variation in VSQI, which confirmed that vegetation restoration type and restoration time are critical for achieving soil reserves. Therefore, it is vital to select appropriate vegetation type in restoration projects and recovery for a long time in order to achieve better soil quality. The current study provides a theoretical basis on which to assess the effects of different vegetation restoration types on the heterogeneous degraded karst areas.
Huiling Guan; Jiangwen Fan. Effects of vegetation restoration on soil quality in fragile karst ecosystems of southwest China. PeerJ 2020, 8, e9456 .
AMA StyleHuiling Guan, Jiangwen Fan. Effects of vegetation restoration on soil quality in fragile karst ecosystems of southwest China. PeerJ. 2020; 8 ():e9456.
Chicago/Turabian StyleHuiling Guan; Jiangwen Fan. 2020. "Effects of vegetation restoration on soil quality in fragile karst ecosystems of southwest China." PeerJ 8, no. : e9456.
The collection of field-based animal data is laborious, risky and costly in some areas, such as various nature reserves. Although multiple studies have used satellite imagery, aerial imagery, and field data individually for some animal species surveys, several technical issues still need to be addressed before full standardization of remote sensing methods for modeling animal population dynamics over large areas. This study is the first to model the population dynamics of livestock in the Longbao Wetland National Nature Reserve, China by utilizing yak estimations from Worldview-2 satellite imagery (0.5 m) collected in 2010 and yaks counted in a ground-based survey conducted in 2011 in combination with the animal population structure precisely extracted from UAS imagery captured in 2016. As a consequence, 5501, 5357, and 5510 yaks were estimated to appear in the reserve in 2010, 2011 and 2016, respectively. In total, 1092, 1062 and 1092 sheep were estimated to appear in the reserve in 2010, 2011 and 2016, respectively. The uncertainty of the presented method is also discussed. Primary experiments show that both the satellite imagery and UAS imagery are promising for use in yak censuses, but no sheep were observed in the satellite imagery because of the low resolution. Compared to the ground-based survey conducted in 2011, the UAS image estimate and satellite imagery count deviated in yak quantity by 2.69% and 2.86%, respectively. UASs are a reliable and low-budget alternative to animal surveys. No discernable changes in animal behaviors and animal distributions were observed as the UAS passed at a height of 700 m, and the accuracy of UAS imagery counts were not significantly affected by the short-distance animal movement and image mosaicking errors. The experimental results illustrate the advantages of the combination of satellite and UAS imagery in modeling animal population dynamics.
Dongliang Wang; Qingjie Song; Xiaohan Liao; Huping Ye; Quanqin Shao; Jiangwen Fan; Nan Cong; Xiaoping Xin; Huanyin Yue; Haiyan Zhang. Integrating satellite and unmanned aircraft system (UAS) imagery to model livestock population dynamics in the Longbao Wetland National Nature Reserve, China. Science of The Total Environment 2020, 746, 140327 .
AMA StyleDongliang Wang, Qingjie Song, Xiaohan Liao, Huping Ye, Quanqin Shao, Jiangwen Fan, Nan Cong, Xiaoping Xin, Huanyin Yue, Haiyan Zhang. Integrating satellite and unmanned aircraft system (UAS) imagery to model livestock population dynamics in the Longbao Wetland National Nature Reserve, China. Science of The Total Environment. 2020; 746 ():140327.
Chicago/Turabian StyleDongliang Wang; Qingjie Song; Xiaohan Liao; Huping Ye; Quanqin Shao; Jiangwen Fan; Nan Cong; Xiaoping Xin; Huanyin Yue; Haiyan Zhang. 2020. "Integrating satellite and unmanned aircraft system (UAS) imagery to model livestock population dynamics in the Longbao Wetland National Nature Reserve, China." Science of The Total Environment 746, no. : 140327.
The implementation of ecological restoration programs is intensively changing the original ecological carrying capacity and the status of ecological security. To evaluate the spatiotemporal variation of ecological carrying capacity and ecological security in China’s eco-engineering areas, an indicator system of ecological carrying capacity and ecological security should be developed. This study developed an evaluation indicator system that contains 29 indicators. The indicators were generated by long-time series and multi-source data. The indicator system presents the relationship between ecological carrying capacity and ecological security and reflects the dynamic change of them in eco-engineering areas. We selected the Three-River Headwaters Region (TRHR) and implemented the Ecological Conservation and Construction Program (ECCP) as a case study. The results showed the variation of ecological carrying capacity (ECC) and ecological security (ES) in the TRHR before (2000–2004), during early term (2005–2009), and during medium term (2010–2015) implementation of ECCP, and limiting factors of ecological carrying capacity and ecological security in TRHR was analyzed. The results showed that the ECC index and the ES index were significantly increase, indicating that the ECC improved and that the ES state got better in the TRHR after implementing ECCP. The water conservation was the major factors limiting the increase of the ECC. The leading factors limiting the improvement of the ES were educational expenditure before 2010 and turned into proportion of tertiary industry and investments for ecological restoration after 2010. The implementation of the ECCP has improved the ES state but has also resulted in new problems. It provides a scientific reference for future research on the indicator system of ecological carrying capacity and ecological security in eco-engineering areas and also has vital practical significance to guide the sustainable development of ecological restoration programs.
Yaxian Zhang; Jiangwen Fan; Suizi Wang. Assessment of Ecological Carrying Capacity and Ecological Security in China’s Typical Eco-Engineering Areas. Sustainability 2020, 12, 3923 .
AMA StyleYaxian Zhang, Jiangwen Fan, Suizi Wang. Assessment of Ecological Carrying Capacity and Ecological Security in China’s Typical Eco-Engineering Areas. Sustainability. 2020; 12 (9):3923.
Chicago/Turabian StyleYaxian Zhang; Jiangwen Fan; Suizi Wang. 2020. "Assessment of Ecological Carrying Capacity and Ecological Security in China’s Typical Eco-Engineering Areas." Sustainability 12, no. 9: 3923.
Frequent snowfall and low temperatures led to a considerable snow disaster in some areas of China’s Three-River Headwaters Region (TRHR) in Qinghai province in the spring of 2019, exerting a considerably negative influence on animal husbandry production in local grasslands. Based on a model of snow disaster classification and quantitative estimations of disaster-stricken animal husbandry, we propose a comprehensive disaster resistance capability index (CDRCI) using remote sensing, ground monitoring, and statistical investigations. With a comprehensive assessment of the space distribution and the magnitude of snow disasters, combined with a quantitative determination of disaster-stricken animal husbandry, the proposed CDRCI calculates how grassland animal husbandry is affected by snow disasters in different counties of the TRHR. The results indicate that approximately 2.31 million sheep and yaks were affected by moderate to severe snow disasters in the TRHR, accounting for 78.3% of the total livestock in the affected region. Of these affected livestock, approximately 1.54 million sheep and yaks were specifically affected by severe snow disasters, accounting for 52.1% of the total number of livestock. The CDRCIs for grassland animal husbandry in both Yushu and were moderate, being higher for the former than for the latter. We confirmed that the proposed CDRCI can accurately evaluate the magnitude of snow disasters in terms of how they affect grassland animal husbandry. The CDRCI is a way of relating the number of animal deaths to spatial disaster prevention and resistance. We expect that this research will provide important theoretical support for formulating snow disaster resistance policy, for example for increasing the construction of grassland animal husbandry infrastructure as well as providing greater stored forage material.
Quanqin Shao; Guobo Liu; Xiaodong Li; Haibo Huang; Jiangwen Fan; Liya Wang; Jiyuan Liu; Xingjian Guo. Assessing the Snow Disaster and Disaster Resistance Capability for Spring 2019 in China’s Three-River Headwaters Region. Sustainability 2019, 11, 6423 .
AMA StyleQuanqin Shao, Guobo Liu, Xiaodong Li, Haibo Huang, Jiangwen Fan, Liya Wang, Jiyuan Liu, Xingjian Guo. Assessing the Snow Disaster and Disaster Resistance Capability for Spring 2019 in China’s Three-River Headwaters Region. Sustainability. 2019; 11 (22):6423.
Chicago/Turabian StyleQuanqin Shao; Guobo Liu; Xiaodong Li; Haibo Huang; Jiangwen Fan; Liya Wang; Jiyuan Liu; Xingjian Guo. 2019. "Assessing the Snow Disaster and Disaster Resistance Capability for Spring 2019 in China’s Three-River Headwaters Region." Sustainability 11, no. 22: 6423.
Known as the “Chinese water tower,” the Three River Headwaters (TRH) region serves an important water retention function. In addition, grassland in this region is mainly used for grazing. However, grazing pressure potentially threatens the balance of this alpine grassland ecosystem. Thus, the influence of grazing activity on water retention needs to be explored. Based on remote sensing, meteorological, government statistics, hydrological records, and field observation data, we used the Integrated Valuation of Environmental Services and Tradeoffs model, grazing pressure index (GPI), and regression analysis to assess water yield (WY) variations and investigate the influence of grazing activity on water retention. The results showed that the grasslands were overloaded in the southern and eastern areas, whereas they had the capacity to carry more livestock in the western and central areas. Grazing pressure negatively impacts on WY in most of the TRH region. Source regions of the Yangtze, Yellow, and Lantsang Rivers also exhibited significant negative correlations between GPI and WY. Grazing decreased the soil water content in the alpine steppe, alpine meadow, and temperate steppe sites at soil depths of 0–30 cm, and a significant decrease was observed in the alpine meadow site at a depth of 10–20 cm. In all the areas, WY tended to decrease with GPI. Regression analyses indicate that GPI could better explain the total WY variation in the alpine meadow than in temperate steppe and alpine steppe. This implies that grazing activity has a negative effect on water retention, particularly in alpine meadows.
Suizi Wang; Jiangwen Fan; Yuzhe Li; Dan Wu; Yaxian Zhang; Lin Huang. Dynamic response of water retention to grazing activity on grassland over the Three River Headwaters region. Agriculture, Ecosystems & Environment 2019, 286, 106662 .
AMA StyleSuizi Wang, Jiangwen Fan, Yuzhe Li, Dan Wu, Yaxian Zhang, Lin Huang. Dynamic response of water retention to grazing activity on grassland over the Three River Headwaters region. Agriculture, Ecosystems & Environment. 2019; 286 ():106662.
Chicago/Turabian StyleSuizi Wang; Jiangwen Fan; Yuzhe Li; Dan Wu; Yaxian Zhang; Lin Huang. 2019. "Dynamic response of water retention to grazing activity on grassland over the Three River Headwaters region." Agriculture, Ecosystems & Environment 286, no. : 106662.
Models constitute the primary approaches for predicting terrestrial ecosystem gross primary production (GPP) at regional and global scales. Many satellite-based GPP models have been developed due to the simple algorithms and the low requirements of model inputs. The performances of these models are well documented at the biome level. However, their performances among vegetation subtypes limited by different environmental stresses within a biome remains largely unexplored. Taking grasslands in northern China as an example, we compared the performance of eight satellite-based GPP models, including three light-use efficiency (LUE) models (vegetation photosynthesis model (VPM), modified VPM (MVPM), and moderate resolution imaging spectroradiometer GPP algorithm (MODIS-GPP)) and five statistical models (temperature and greenness model (TG), greenness and radiation model (GR), vegetation index model (VI), alpine vegetation model (AVM), and photosynthetic capacity model (PCM)), between the water-limited temperate steppe and the temperature-limited alpine meadow based on 16 site-year GPP estimates at four eddy covariance (EC) flux towers. The results showed that all the GPP models performed better in the alpine meadow, particularly in the alpine shrub meadow (R2 ≥ 0.84), than in the temperate steppe (R2 ≤ 0.68). The performance varied greatly among the models in the temperate steppe, while slight intermodel differences existed in the alpine meadow. Overall, MVPM (of the LUE models) and VI (of the statistical models) were the two best-performing models in the temperate steppe due to their better representation of the effect of water stress on vegetation productivity. Additionally, we found that the relatively worse model performances in the temperate steppe were seriously exaggerated by drought events, which may occur more frequently in the future. This study highlights the varying performances of satellite-based GPP models among vegetation subtypes of a biome in different precipitation years and suggests priorities for improving the water stress variables of these models in future efforts.
Liangxia Zhang; Decheng Zhou; Jiangwen Fan; Qun Guo; Shiping Chen; Ranghui Wang; Yuzhe Li. Contrasting the Performance of Eight Satellite-Based GPP Models in Water-Limited and Temperature-Limited Grassland Ecosystems. Remote Sensing 2019, 11, 1333 .
AMA StyleLiangxia Zhang, Decheng Zhou, Jiangwen Fan, Qun Guo, Shiping Chen, Ranghui Wang, Yuzhe Li. Contrasting the Performance of Eight Satellite-Based GPP Models in Water-Limited and Temperature-Limited Grassland Ecosystems. Remote Sensing. 2019; 11 (11):1333.
Chicago/Turabian StyleLiangxia Zhang; Decheng Zhou; Jiangwen Fan; Qun Guo; Shiping Chen; Ranghui Wang; Yuzhe Li. 2019. "Contrasting the Performance of Eight Satellite-Based GPP Models in Water-Limited and Temperature-Limited Grassland Ecosystems." Remote Sensing 11, no. 11: 1333.
Being subject to climate change and human intervention, the land-use pattern in the agro-pastoral ecotone of Northern China has undergone complex changes over the past few decades, which may jeopardize the provision of ecosystem services. Thus, for sustainable land management, ecosystem services should be evaluated and monitored. In this study, based on Landsat TM/ETM data, we quantitatively evaluated the losses of ecosystem service values (ESV) in three sections of the agro-pastoral ecotone from 1980–2015. The results were as follows: (1) the main characteristic of the land conversions was that a large area of grassland was converted into cultivated land in the agro-pastoral ecotone; (2) on the spatial scale, the ESV losses of the agro-pastoral ecotone can be called an “inclined surface” in the direction of the northeast to southwest, and the northeastern section of the agro-pastoral ecotone lost more ESV than the middle and northwest sections (p < 0.05), on the temporal scale, the order of losses was 1990–2000 > 1980–1990 > 2000–2015; (3) the agro-pastoral ecotone lost more ESV, which was mainly due to four kinds of land conversion, which were grassland that was transformed into cultivated land, grassland transformed into unused land, grassland transformed into built-up areas, and cultivated land transformed into built-up areas; (4) although these land conversions were curbed after the implementation of protection policies at the end of the 1990s, due to reduced precipitation and increasing temperatures, the agro-pastoral ecotone will face a more severe situation in the future; and, (5) during the period of 1990–2015, the overall dynamic processes of increasing population gradually expanded to the sparsely populated pastoral area. Therefore, we believe that human interventions are the main cause of ecological deterioration in the agro-pastoral ecotone. This study provides references for fully understanding the regional differences in the ecological and environmental effects of land use change and it helps to objectively evaluate ecological civilization construction in the agro-pastoral ecotone of Northern China.
Yuejuan Yang; Kun Wang; Di Liu; Xinquan Zhao; Jiangwen Fan; Jinsheng Li; Xiajie Zhai; Cong Zhang; Ruyi Zhan. Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China. International Journal of Environmental Research and Public Health 2019, 16, 1199 .
AMA StyleYuejuan Yang, Kun Wang, Di Liu, Xinquan Zhao, Jiangwen Fan, Jinsheng Li, Xiajie Zhai, Cong Zhang, Ruyi Zhan. Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China. International Journal of Environmental Research and Public Health. 2019; 16 (7):1199.
Chicago/Turabian StyleYuejuan Yang; Kun Wang; Di Liu; Xinquan Zhao; Jiangwen Fan; Jinsheng Li; Xiajie Zhai; Cong Zhang; Ruyi Zhan. 2019. "Spatiotemporal Variation Characteristics of Ecosystem Service Losses in the Agro-Pastoral Ecotone of Northern China." International Journal of Environmental Research and Public Health 16, no. 7: 1199.
Grasslands in northern China form an important ecological barrier that prevents and controls desertification. The Beijing–Tianjin Sand Source Control (BTSSC) Project has been implemented to restore grassland in order to control sand sourced pollution. This study aimed to understand the impacts of four applied restoration practices on the productivity, composition, and species diversity of vegetation communities in the BTSSC Project. The results indicated the following: (1) All the restoration practices tended to increase the height and cover of communities, and the effect was most obvious where grazing was excluded; (2) total biomass (87%), above-ground biomass (164%) and below-ground biomass (58%) only increased consistently when grazing was excluded from the steppe; (3) fenced and grazing exclusion practice significantly increased the abundance of species in communities, but all the practices tended to decrease the evenness of species; and, (4) the correlation analysis revealed that the Shannon–Wiener diversity index, and Pielou evenness index, showed significant negative correlations with the above-ground biomass of grassland communities after restoration, while no significant relationships were shown in reference plots. Our comparison of applied practices in the BTSSC project revealed that grazing exclusion might be a high priority for more successful restoration in this region.
Yuzhe Li; Jiangwen Fan; Hailing Yu. Grazing Exclusion, a Choice between Biomass Growth and Species Diversity Maintenance in Beijing—Tianjin Sand Source Control Project. Sustainability 2019, 11, 1941 .
AMA StyleYuzhe Li, Jiangwen Fan, Hailing Yu. Grazing Exclusion, a Choice between Biomass Growth and Species Diversity Maintenance in Beijing—Tianjin Sand Source Control Project. Sustainability. 2019; 11 (7):1941.
Chicago/Turabian StyleYuzhe Li; Jiangwen Fan; Hailing Yu. 2019. "Grazing Exclusion, a Choice between Biomass Growth and Species Diversity Maintenance in Beijing—Tianjin Sand Source Control Project." Sustainability 11, no. 7: 1941.
Livestock grazing is an important determinant of species diversity and plant growth. Overgrazing is identified as one of the most important disturbances resulting in grassland degradation. Although many restoration practices have been implemented, grazing exclusion is one of the most effective methods to restore degraded grasslands. We explored the impact of five years of grazing exclusion on plant growth and species diversity in four types of grasslands: temperate steppe (TS), swamp meadow (SM), alpine steppe (AS), and alpine meadow (AM). Our results showed that grazing exclusion increased plant height, coverage, biomass, and species diversity in all four grasslands. The aboveground biomass in AM (180.8%), TS (117.3%), and SW (105.9%) increased significantly more than AS (10.1%). Grazing exclusion in AM had the greatest effect on proportion of palatable species, and the increase in palatable species in AM was higher than that of the other grassland types significantly. Species diversity increased significantly within the enclosure in SM (23.9%) and AM (20.8%). Our results indicate that grazing exclusion is an effective management strategy to restore degraded grasslands and it works best in alpine meadow. This study contributes to the growing theoretical basis for grassland management strategies and has a significant effect on sustainable development for grassland resources and pastoral areas.
Suizi Wang; Jiangwen Fan; Yuzhe Li; Lin Huang. Effects of Grazing Exclusion on Biomass Growth and Species Diversity among Various Grassland Types of the Tibetan Plateau. Sustainability 2019, 11, 1705 .
AMA StyleSuizi Wang, Jiangwen Fan, Yuzhe Li, Lin Huang. Effects of Grazing Exclusion on Biomass Growth and Species Diversity among Various Grassland Types of the Tibetan Plateau. Sustainability. 2019; 11 (6):1705.
Chicago/Turabian StyleSuizi Wang; Jiangwen Fan; Yuzhe Li; Lin Huang. 2019. "Effects of Grazing Exclusion on Biomass Growth and Species Diversity among Various Grassland Types of the Tibetan Plateau." Sustainability 11, no. 6: 1705.
Soil organic carbon (SOC) plays an important role in global carbon cycling and is increasingly important to the ecosystem. An accurate SOC content map would significantly contribute to the proper application of ecological modeling. Therefore, there is a need to accurately estimate and map SOC content in grasslands. We evaluated various methods for estimating the SOC content of grasslands using field soil sampling data and auxiliary data in the pastoral area. The results showed that (1) SOC is affected by various factors, including geographic location, soil, topography, and climate. Single-variable SOC models account for 2%–72% of the variations in the grassland SOC. (2) Based on the correlation of environmental variables of SOC, normalized difference vegetation index, annual precipitation, annual average temperature, elevation, and moisture index were explored as critical auxiliary data to predict SOC content. We established multi-factor weighted regression model (MWRM). (3) We compared three spatial estimation methods, including inverse distance weighting, regression kriging, and MWRM, to determine a suitable method for SOC mapping. Our results indicate that among the three spatial estimation methods, MWRM provides the lowest prediction error (RMSE = 4.85 g/kg; MAE = 3.47 g/kg; MRE = 24.04%) and highest R2 (0.89) and Lin's concordance (0.94) values in the spatial estimation at a 0–10 cm soil layer. (4) Therefore, we applied MWRM to predict SOC content at various layers, and its SOC content prediction in the topsoil (0–20 cm) is better than that in the subsurface (20–30 cm) and subsoil (30–40 cm). The SOC content spatial distribution demonstrated a similar pattern for each soil layer and the SOC content gradually decreased with increasing soil depth.
Suizi Wang; Jiangwen Fan; Huaping Zhong; Yuzhe Li; Huazhong Zhu; Yuxin Qiao; Haiyan Zhang. A multi-factor weighted regression approach for estimating the spatial distribution of soil organic carbon in grasslands. CATENA 2018, 174, 248 -258.
AMA StyleSuizi Wang, Jiangwen Fan, Huaping Zhong, Yuzhe Li, Huazhong Zhu, Yuxin Qiao, Haiyan Zhang. A multi-factor weighted regression approach for estimating the spatial distribution of soil organic carbon in grasslands. CATENA. 2018; 174 ():248-258.
Chicago/Turabian StyleSuizi Wang; Jiangwen Fan; Huaping Zhong; Yuzhe Li; Huazhong Zhu; Yuxin Qiao; Haiyan Zhang. 2018. "A multi-factor weighted regression approach for estimating the spatial distribution of soil organic carbon in grasslands." CATENA 174, no. : 248-258.
Soil erosion caused by wind is a serious environmental problem that results in land degradation and threatens sustainable development. Accurately evaluating wind erosion dynamics is important for reducing the hazard of wind erosion. Separating the climatic and anthropogenic causes of wind erosion can improve the understanding of its driving mechanisms. Based on meteorological, remote sensing and field observation data, we applied the Revised Wind Erosion Equation (RWEQ) to simulate wind erosion in Inner Mongolia, China from 1990 to 2015. We used the variable control method by input of the average climate conditions to calculate human-induced wind erosion. The difference between natural wind erosion and human-induced wind erosion was determined to assess the effect of climate change on wind erosion. The results showed that the wind erosion modulus had a remarkable decline with a slope of 52.23 t/km2/a from 1990 to 2015. During 26 years, the average wind erosion for Inner Mongolia amounted to 63.32 billion tons. Wind erosion showed an overall significant decline of 49.23% and the partial severer erosion hazard significantly increased by 7.11%. Of the significant regional decline, 40.72% was caused by climate changes, and 8.51% was attributed to ecological restoration programs. For the significant regional increases of wind erosion, 4.29% was attributed to climate changes and 2.82% to human activities, mainly overgrazing and land use/cover changes. During the study, the driving forces in Inner Mongolia of wind erosion dynamics differed spatially. Timely monitoring based on multi-source data and highlighting the importance of positive human activities by increasing vegetation coverage for deserts, reducing grazing pressure on grasslands, establishing forests as windbreaks and optimizing crop planting rotations of farmlands can all act to reduce and control wind erosion.
Haiyan Zhang; Jiangwen Fan; Wei Cao; Warwick Harris; Yuzhe Li; Wenfeng Chi; Suizi Wang. Response of wind erosion dynamics to climate change and human activity in Inner Mongolia, China during 1990 to 2015. Science of The Total Environment 2018, 639, 1038 -1050.
AMA StyleHaiyan Zhang, Jiangwen Fan, Wei Cao, Warwick Harris, Yuzhe Li, Wenfeng Chi, Suizi Wang. Response of wind erosion dynamics to climate change and human activity in Inner Mongolia, China during 1990 to 2015. Science of The Total Environment. 2018; 639 ():1038-1050.
Chicago/Turabian StyleHaiyan Zhang; Jiangwen Fan; Wei Cao; Warwick Harris; Yuzhe Li; Wenfeng Chi; Suizi Wang. 2018. "Response of wind erosion dynamics to climate change and human activity in Inner Mongolia, China during 1990 to 2015." Science of The Total Environment 639, no. : 1038-1050.
Accurate and periodic assessment of grassland yield (GY) is of great importance for the management of high altitude plateau grasslands. The Tibetan Plateau (TP) is a very important pastoral area that provides a microcosm of typical alpine grassland ecosystems. Based on remote sensing data, meteorological datasets and observational plant biomass data, we used the Global Production Efficiency Model and Soil and Atmosphere Model (GLOPEM-CEVSA) to estimate GY and its response to climate change and anthropogenic activities on the TP from 1988 to 2013. We quantitatively analyzed spatiotemporal dynamic changes of GY for four geomorphological divisions and five main grassland types. For the 26 years of the study, average annual total GY was 515.8 kg/ha/yr and gradually decreased from the southeast to the northwest of the TP. Annual GY fluctuated from year to year but had an overall positive trend (4.2 kg/ha/yr). Spatiotemporal variation of GY was greatly influenced by spatial heterogeneity. For the total area, the proportion showing a significant increase in GY was 45.2%, while only 12.6% showed a significant decrease. For the main grassland types, GY of Alpine Meadow was highest and had the highest slope of increase. The pattern of decrease of GY from the southeast to the northwest was predominantly related to climate gradients. Regional correlation analysis indicated that warming temperature promoted positive increase of GY for almost all the region. Annual precipitation was related to a less significant decreasing trend of GY over all the TP apart from an increase of GY in the middle area of the north. The grazing pressure index decreased over the years by control of livestock numbers, the reduction of grazing pressure assisting restoration of alpine grasslands. However, grazing pressure on the TP in 2013 remained too high and overloaded. Nevertheless, grassland protection and restoration projects have mitigated grassland degradation in some areas, promoted grassland restoration, and increased incomes of herdsmen. The study indicates that continuation of these projects is critical for the restoration and sustainable use of the TP grasslands.
Haiyan Zhang; Jiangwen Fan; Junbang Wang; Wei Cao; Warwick Harris. Spatial and temporal variability of grassland yield and its response to climate change and anthropogenic activities on the Tibetan Plateau from 1988 to 2013. Ecological Indicators 2018, 95, 141 -151.
AMA StyleHaiyan Zhang, Jiangwen Fan, Junbang Wang, Wei Cao, Warwick Harris. Spatial and temporal variability of grassland yield and its response to climate change and anthropogenic activities on the Tibetan Plateau from 1988 to 2013. Ecological Indicators. 2018; 95 ():141-151.
Chicago/Turabian StyleHaiyan Zhang; Jiangwen Fan; Junbang Wang; Wei Cao; Warwick Harris. 2018. "Spatial and temporal variability of grassland yield and its response to climate change and anthropogenic activities on the Tibetan Plateau from 1988 to 2013." Ecological Indicators 95, no. : 141-151.
We used unmanned aerial vehicles (UAVs) to carry out a relatively complete population census of large wild herbivores in Maduo County on the Tibetan Plateau in the spring of 2017. The effective area covered by aerial surveys was 326.6 km2, and 23,784 images were acquired. Interpretation tag libraries for UAV images were created for wild animals, including Kiang (Equus kiang), Tibetan gazelle (Procapra picticaudata), and blue sheep (Pseudois nayaur), as well as livestock, including yaks and Tibetan sheep. Large wild herbivores in the survey transect were identified through manual imagery interpretation. Densities ranged from 1.15/km2 for Kiang, 0.61/km2 for Tibetan gazelle, 0.62/km2 for blue sheep, 4.12/km2 for domestic yak, and 7.34/km2 for domestic sheep. A method based on meadows in the cold and warm seasons was used for estimating the densities and numbers of large wild herbivores and livestock, and was verified against records of livestock numbers. Population estimates for Kiang, Tibetan gazelle, blue sheep, domestic yak, and domestic sheep were 17,109, 15,961, 9324, 70,846, and 102,194, respectively. Based on published consumption estimates, the results suggest that domestic stock consume 4.5 times the amount of vegetation of large wild herbivores. Compared with traditional ground survey methods, performance of UAV remote sensing surveys of large wild herbivore populations was fast, economical and reliable, providing an effective future method for surveying wild animals.
Xingjian Guo; Quanqin Shao; Yuzhe Li; Yangchun Wang; Dongliang Wang; Jiyuan Liu; Jiangwen Fan; Fan Yang. Application of UAV Remote Sensing for a Population Census of Large Wild Herbivores—Taking the Headwater Region of the Yellow River as an Example. Remote Sensing 2018, 10, 1041 .
AMA StyleXingjian Guo, Quanqin Shao, Yuzhe Li, Yangchun Wang, Dongliang Wang, Jiyuan Liu, Jiangwen Fan, Fan Yang. Application of UAV Remote Sensing for a Population Census of Large Wild Herbivores—Taking the Headwater Region of the Yellow River as an Example. Remote Sensing. 2018; 10 (7):1041.
Chicago/Turabian StyleXingjian Guo; Quanqin Shao; Yuzhe Li; Yangchun Wang; Dongliang Wang; Jiyuan Liu; Jiangwen Fan; Fan Yang. 2018. "Application of UAV Remote Sensing for a Population Census of Large Wild Herbivores—Taking the Headwater Region of the Yellow River as an Example." Remote Sensing 10, no. 7: 1041.
Carbon-use efficiency (CUE) is the proportion of gross primary production converted to net primary production. Changes to CUE strongly influence ecosystem carbon budgets and turnover. Little is known about the response of ecosystem CUE to human-induced land-use change, which limits the accurate evaluation of the environmental influence of large-scale steppe-use changes in northern China. We investigated the components of ecosystem carbon exchange and CUE under three typical steppe-use patterns in Xilinhot, Inner Mongolia. The results showed that CUE in grazing and grazing-excluded steppe were not significantly different (both over 0.7) but were significantly higher than in cultivated steppe (0.57). Ecosystem respiration and its components, including autotrophic respiration (Ra), aboveground respiration, heterotrophic respiration and belowground respiration showed significant negative correlation with CUE. Ra is the most important factor explaining the variation of CUE between different steppe-use patterns (p < 0.001, 97%); Ra change may be the primary factor driving CUE variation between steppe-use patterns. Leaf area index of different grassland-use patterns also showed a significant negative correlation with CUE (p < 0.001, 91%). These findings may help to improve accurate prediction of the environmental and climatic consequences of large-scale land-use change.
Yuzhe Li; Jiangwen Fan; Zhongmin Hu. Comparison of Carbon-Use Efficiency Among Different Land-Use Patterns of the Temperate Steppe in the Northern China Pastoral Farming Ecotone. Sustainability 2018, 10, 487 .
AMA StyleYuzhe Li, Jiangwen Fan, Zhongmin Hu. Comparison of Carbon-Use Efficiency Among Different Land-Use Patterns of the Temperate Steppe in the Northern China Pastoral Farming Ecotone. Sustainability. 2018; 10 (2):487.
Chicago/Turabian StyleYuzhe Li; Jiangwen Fan; Zhongmin Hu. 2018. "Comparison of Carbon-Use Efficiency Among Different Land-Use Patterns of the Temperate Steppe in the Northern China Pastoral Farming Ecotone." Sustainability 10, no. 2: 487.
Unmanned aerial vehicle surveys were conducted in the summer season of 2016 and the winter season of 2017 to investigate the large wild herbivore population, including kiangs, Tibetan gazelles and bharals, in Madoi County; the source region of the Yellow River. The study generated forage grass production data in 30 m spatial resolution in Madoi County in 2016 using a downscaling algorithm; estimated a forage-livestock balance including wild animals and domestic animals; and analyzed the effect of the large wild herbivore population on the balance between forage grass and herbivory in Madoi County. The large wild herbivore population was estimated based on the density of the animals in the survey sample strip and compared and verified with available statistical data and the two survey results from the summer season of 2016 and winter season of 2017. The results showed that: (1) in the winter season of 2017, the populations of kiang, Tibetan gazelle and bharal were 17,100, 16,000 and 9300, respectively, while the populations of domestic yak, Tibetan sheep and horse were 70,800, 102,200 and 1200, respectively. The total population of large wild herbivores and domestic animals was 475,000 (sheep units). The ratio (in sheep units) between large wild herbivores and domestic animals was 1:4.5; (2) When only considering domestic animals, the grazing pressure index was 1.13, indicating slight overloading of the grassland. When considering domestic animals and large wild herbivores (kiang, Tibetan gazelle and bharal), the grazing pressure index was 1.38, suggesting moderate overloading of the grassland; (3) If large wild herbivores are not taken into consideration when the forage-livestock balance is calculated, the grazing pressure will be under-estimated by 22%. Overgrazing is the major cause of grassland degradation in Madoi County. An additional 79,000 tons of hay or a 30% reduction in domestic animals is required to maintain a forage-livestock balance in Madoi County.
Fan Yang; Quanqin Shao; Xingjian Guo; Yuzhi Tang; Yuzhe Li; Dongliang Wang; Yangchun Wang; Jiangwen Fan. Effect of Large Wild Herbivore Populations on the Forage-Livestock Balance in the Source Region of the Yellow River. Sustainability 2018, 10, 340 .
AMA StyleFan Yang, Quanqin Shao, Xingjian Guo, Yuzhi Tang, Yuzhe Li, Dongliang Wang, Yangchun Wang, Jiangwen Fan. Effect of Large Wild Herbivore Populations on the Forage-Livestock Balance in the Source Region of the Yellow River. Sustainability. 2018; 10 (2):340.
Chicago/Turabian StyleFan Yang; Quanqin Shao; Xingjian Guo; Yuzhi Tang; Yuzhe Li; Dongliang Wang; Yangchun Wang; Jiangwen Fan. 2018. "Effect of Large Wild Herbivore Populations on the Forage-Livestock Balance in the Source Region of the Yellow River." Sustainability 10, no. 2: 340.
N and P concentrations and their ratios were determined for 132 foliar and 120 below-ground biomass (BGB) samples obtained at 132 sites along the 4500 km Chinese Grassland Transect (CGT) across the Inner Mongolian and Qinghai–Tibet Plateaus. Patterns of foliar and BGB N, P and their ratio (N/P) at the community level were related to altitude, temperature, and precipitation gradients. Also, patterns of relative N and P foliar and BGB concentrations were determined (NF/B, foliar N/BGB N; PF/B, foliar P/BGB P). The relationship between foliar N concentrations and mean annual temperature (MAT) was negative, agreeing with the Temperature-Plant Physiological hypothesis, whereas BGB N decreased with decreasing MAT, supporting the Biogeochemical hypothesis. Patterns of BGB N varying with altitude, MAP and MAT differed from the patterns for leaf N, which may indicate differences in nutrient allocation and utilization by leaves and BGB. NF/B and PF/B may reflect trade-offs by plants for N and P in leaves and BGB. For the entire CGT, NF/B and PF/B increased as altitude increased. NF/B was positively related with MAP but negatively related with MAT, while PF/B showed no correlations with MAP and MAT. Results suggest that ecological stoichiometry at the community level is similar to that at the species level. Strategies of nutrient utilization by leaves and BGB are indicated to be different, and abiotic environmental conditions could influence the stoichiometric characteristics and nutrient allocation to leaves and BGB.
Hailing Yu; Jiangwen Fan; Warwick Harris; Yuzhe Li. Relationships between below-ground biomass and foliar N:P stoichiometry along climatic and altitudinal gradients of the Chinese grassland transect. Plant Ecology 2017, 218, 661 -671.
AMA StyleHailing Yu, Jiangwen Fan, Warwick Harris, Yuzhe Li. Relationships between below-ground biomass and foliar N:P stoichiometry along climatic and altitudinal gradients of the Chinese grassland transect. Plant Ecology. 2017; 218 (6):661-671.
Chicago/Turabian StyleHailing Yu; Jiangwen Fan; Warwick Harris; Yuzhe Li. 2017. "Relationships between below-ground biomass and foliar N:P stoichiometry along climatic and altitudinal gradients of the Chinese grassland transect." Plant Ecology 218, no. 6: 661-671.
To mitigate impacts of sandstorms on northern China, the Chinese government launched the Beijing–Tianjin Sand Source Control Program (BTSSCP) in 2000. The associated practices (i.e., cultivation, enclosure, and aerial seeding) were expected to greatly enhance grassland carbon sequestration. However, the BTSSCP-induced soil organic carbon (SOC) dynamics remain elusive at a regional level. Using the Xilingol League in Inner Mongolia for a case study, we examined the impacts from 2000 to 2006 of the BTSSCP on SOC stocks using the IPCC carbon budget inventory method. Results indicated that over all practices SOC storage increased by 1.7%, but there were large differences between practices. SOC increased most rapidly at the rate of 0.3 Mg C•ha–1•yr–1 under cultivation, but decreased significantly under aerial seeding with moderate or heavy grazing (0.3 vs.0.6 Mg C•ha–1•yr–1). SOC increases varied slightly for grassland types, ranging from 0.10 Mg C•ha–1•yr–1 for temperate desert steppe to 0.16 Mg C•ha–1•yr–1 for temperate meadow steppe and lowland meadow. The overall economic benefits of the SOC sink were estimated to be 4.0 million CNY. Aerial seeding with no grazing was found to be the most cost-effective practice. Finally, we indicated that at least 55.5 years (shortest for cultivation) were needed for the grasslands to reach their potential carbon stocks. Our findings highlight the importance and effectiveness of BTSSCP in promoting terrestrial carbon sequestration which may help mitigate climate change, and further stress the need for more attention to the effectiveness of specific practices.
Liangxia Zhang; Wei Cao; Jiangwen Fan. Soil organic carbon dynamics in Xilingol grassland of northern China induced by the Beijing-Tianjin Sand Source Control Program. Frontiers of Earth Science 2016, 11, 407 -415.
AMA StyleLiangxia Zhang, Wei Cao, Jiangwen Fan. Soil organic carbon dynamics in Xilingol grassland of northern China induced by the Beijing-Tianjin Sand Source Control Program. Frontiers of Earth Science. 2016; 11 (2):407-415.
Chicago/Turabian StyleLiangxia Zhang; Wei Cao; Jiangwen Fan. 2016. "Soil organic carbon dynamics in Xilingol grassland of northern China induced by the Beijing-Tianjin Sand Source Control Program." Frontiers of Earth Science 11, no. 2: 407-415.
Nitrogen (N) and phosphorus (P) are most commonly the limiting essential elements that affect the functioning of plants and ecosystems. However, their stoichiometry in relation to climatic variables and vegetation organization levels has not been comprehensively characterized. N and P concentrations were measured for 329 leaf samples collected at 132 sites along the 5000 km long China Grassland Transect that traverses the Inner Mongolian and Qinghai-Tibet Plateaus. The patterns of these measurements were analyzed with reference to climate factors, plant species, plant functional groups, grassland communities and grassland ecosystems. The aim was to explore whether geographical patterns of plant leaf elements are related to zonal climatic variables, and at which vegetation organization levels changes of plant leaf N and P stoichiometric characteristics and pattern occur. Results showed that interspecific differences of N and P concentrations were most significant for the three vegetation organization levels of species, community and ecosystem. Plant leaf N and P concentrations were higher, coefficients of variation of N and P lower, and N/P, C/N and C/P ratios were also lower for leaf samples from the cold high altitude Qinghai-Tibet Plateau than for those from the relatively lower altitude and warmer Inner Mongolian Plateau. Correlation of N and P for Inner Mongolian grassland was higher than that for the Qinghai-Tibet Plateau. The study indicates plant species are the most basic unit influencing plant stoichiometric geographic patterns, and that climatic variables affect leaf element concentrations mainly through their effect on changes of plant species composition of vegetation.
Jiangwen Fan; Warwick Harris; Huaping Zhong. Stoichiometry of leaf nitrogen and phosphorus of grasslands of the Inner Mongolian and Qinghai-Tibet Plateaus in relation to climatic variables and vegetation organization levels. Ecological Research 2016, 31, 821 -829.
AMA StyleJiangwen Fan, Warwick Harris, Huaping Zhong. Stoichiometry of leaf nitrogen and phosphorus of grasslands of the Inner Mongolian and Qinghai-Tibet Plateaus in relation to climatic variables and vegetation organization levels. Ecological Research. 2016; 31 (6):821-829.
Chicago/Turabian StyleJiangwen Fan; Warwick Harris; Huaping Zhong. 2016. "Stoichiometry of leaf nitrogen and phosphorus of grasslands of the Inner Mongolian and Qinghai-Tibet Plateaus in relation to climatic variables and vegetation organization levels." Ecological Research 31, no. 6: 821-829.
Foliar elements and their ratios can be related to foliar carbon isotope composition (δ13C) through their involvement in plant transpiration, photosynthesis, and osmotic adjustment. In order to investigate these relationships in grasslands of Inner Mongolia, China, δ13C and element contents of dominant C3 species at 47 grassland sites were determined. For C3 species, δ13C showed no correlation with carbon (C), positive correlations with nitrogen (N), nitrogen:phosphorus ratio (N/P) and carbon:phosphorus ratio (C/P), and negative correlations with phosphorus (P), potassium (K), and carbon:nitrogen ratio (C/N), while correlation with P was subsidiary to positive correlation between P and K. These correlations indicate that plants in Inner Mongolia that survive in dry conditions may profit from their higher water use efficiency via stomatal regulation and N-related photosynthetic capacity rather than K-related osmotic adjustment and P-related photosynthetic capacity. Further, plants adapt to severe environments by having higher water and phosphorus use efficiency at the expense of nitrogen use efficiency. However, these correlations differed among plant functional groups (PFGs), e.g., δ13C was negatively correlated with N in shrubs in contrast to other life forms. A possible explanation is that shrubs adapt to low N availability by having lower photosynthetic nitrogen use efficiency (PNUE), so that N is not positively related to photosynthetic rate in shrubs. Obviously, data on stomatal conductance, PNUE, and cell osmotic pressure are needed to fully understand these correlations and the strategies of plants adapted to arid environments.
Yong-Chun Zhou; Xi-Lei Cheng; Jiang-Wen Fan; Warwick Harris. Relationships between foliar carbon isotope composition and elements of C3 species in grasslands of Inner Mongolia, China. Plant Ecology 2016, 217, 883 -897.
AMA StyleYong-Chun Zhou, Xi-Lei Cheng, Jiang-Wen Fan, Warwick Harris. Relationships between foliar carbon isotope composition and elements of C3 species in grasslands of Inner Mongolia, China. Plant Ecology. 2016; 217 (7):883-897.
Chicago/Turabian StyleYong-Chun Zhou; Xi-Lei Cheng; Jiang-Wen Fan; Warwick Harris. 2016. "Relationships between foliar carbon isotope composition and elements of C3 species in grasslands of Inner Mongolia, China." Plant Ecology 217, no. 7: 883-897.