scholarly journals Human Activities Introduced Degenerations of Wetlands (1975–2013) across the Sanjiang Plain North of the Wandashan Mountain, China

Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1361
Author(s):  
Jing Xie ◽  
Yeran Sun ◽  
Xiao Liu ◽  
Zhi Ding ◽  
Ming Lu
Keyword(s):  
Land Use ◽  
Agricultural Development ◽  
Arable Land ◽  
Wetland Loss ◽  
Sanjiang Plain ◽  
Rapid Expansion ◽  
Wetland Protection ◽  
Landsat Images ◽  
The Sanjiang Plain ◽  
Backtracking Analysis

Human-induced dramatic loss and fragmentation of wetlands need further understanding through historical backtracking analysis at a geographical landscape scale. In this study, we investigated time-series wetlands maps from 1975, 1983, 1989, 2000, 2006, and 2013 derived from Landsat images based on the object-oriented classification of wetlands across the Sanjiang Plain north of the Wandashan Mountains. The spatial and temporal changes in the wetlands that occurred at different time periods and the Euclidean distances between artificial land-use types and natural land-cover areas were evaluated for their impact. Our results showed that wetland was the dominant landscape in 1975; however, arable land became the main land coverage in 2013 owing to severe changes in agricultural development over the past decades. The closer to arable land, the greater the wetland loss during the entire investigated period; agriculture activities were the dominant driving force for the degradation of wetlands based on landscape changes; secondary was the rapid expansion in building land use (i.e., human settlement, transportation, and establishment of irrigation canals). More specifically, the rapid loss of wetland areas over 1975–2000 was mainly owing to extensive agricultural reclamation. The mitigated loss of wetland areas over 2000–2013 was because of the protection and restored implementation of wetlands under governmental policies. The wetlands of the study area suffered severe human disturbance, and our analysis may help explain the loss process of wetlands, but more effective management and administration is still needed to address the issues around the balance between agricultural production and wetland protection for further sustainable development.

scholarly journals Using Multisource Geospatial Data to Identify Potential Wetland Rehabilitation Areas: A Pilot Study in China’s Sanjiang Plain

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2496 ◽  
Author(s):  
Zhiqiang Qiu ◽  
Ling Luo ◽  
Dehua Mao ◽  
Baojia Du ◽  
Kaidong Feng ◽  
...  
Keyword(s):  
Sustainable Development Goals ◽  
Wetland Loss ◽  
Sanjiang Plain ◽  
Geospatial Data ◽  
Ecosystem Functions ◽  
Wetland Protection ◽  
The Sanjiang Plain ◽  
Degraded Ecosystem ◽  
Development Goals ◽  
Wetland Rehabilitation

Wetland rehabilitation, highlighted in the United Nations (UN) Sustainable Development Goals (SDGs), is imperative for responding to decreased regional biodiversity and degraded ecosystem functions and services. Knowing where the most suitable wetland rehabilitation areas are can strengthen scientific planning and decision-making for natural wetland conservation and management implementation. Therefore, we integrated multisource geospatial data characterizing hydrological, topographical, management, and policy factors, including maximum surface water coverage, farming time, anthropogenic disturbance, and wetland protection level, to identify potential wetland rehabilitation areas in the Sanjiang Plain (SJP), the largest marsh distribution and a hotspot wetland loss region in China. Our results indicate that a total of 11,643 km2 of wetlands were converted into croplands for agricultural production from 1990 to 2018. We estimated that 5415 km2 of the croplands were suitable for wetland rehabilitation in the SJP, of which 4193 km2 (77%) have high rehabilitation priority. Specifically, 63% of the potential areas available for wetland rehabilitation are dry croplands (3419 km2), the rest (37%) being paddy fields. We argue that the selected indicators and approach used in this study to determine potential wetland rehabilitation areas could guide their investigation, at either the provincial or national scale and would be beneficial to conservation and sustainable management of wetlands in the SJP.

scholarly journals Land use change effects on diversity of soil bacterial, Acidobacterial and fungal communities in wetlands of the Sanjiang Plain, northeastern China

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xin Sui ◽  
Rongtao Zhang ◽  
Beat Frey ◽  
Libin Yang ◽  
Mai-He Li ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Community ◽  
Land Use Change ◽  
Arable Land ◽  
Sanjiang Plain ◽  
Fungal Communities ◽  
Wetland Soils ◽  
The Sanjiang Plain ◽  
Soil Microbial ◽  
Soil Bacterial

AbstractThe bacterial, acidobacterial, and fungal communities in wetlands can undergo perturbations by various human activities, such as disturbances caused by cultivation and during the process of system restoration. In this study, we investigated the relationships between the composition of the soil bacterial, acidobacterial, and fungal communities and the transformation of wetlands by human activities in the Sanjiang Plain. Soil microbial communities were assessed in wetland soils collected from pristine marsh, neighboring cropland (wetland turned into arable land), and land that had been reforested with Larix gmelinii. The alpha-diversities of bacteria, Acidobacteria, and fungi were affected by land-use change and were highest in the arable land and lowest in the wetland soils. The soil microbial community structures were also altered with changing land-use. Canonical correlation analyses showed that beta-diversity was significantly affected by soil pH, available phosphorus, soil nitrogen, and total organic carbon. Overall, our results showed that the agricultural cultivation of wetlands changes the available soil carbon, nitrogen, and phosphorus pools, thereby influencing the bacterial, acidobacterial, and fungal diversity and community structure. Once the soil microbial community has been altered by human activity, it might be difficult to restore it to its original state. These findings highlight the importance of effectively maintaining the diversity of soil bacterial, Acidobacterial, and fungal communities despite land use change in order to sustain a microbial community diversity and ecosystem function.

scholarly journals Simulating Land-Use Changes and Predicting Maize Potential Yields in Northeast China for 2050

2021 ◽  
Vol 18 (3) ◽  
pp. 938
Author(s):  
Luoman Pu ◽  
Jiuchun Yang ◽  
Lingxue Yu ◽  
Changsheng Xiong ◽  
Fengqin Yan ◽  
...  
Keyword(s):  
Land Use ◽  
Food Security ◽  
Northeast China ◽  
Land Use Changes ◽  
Sanjiang Plain ◽  
Potential Production ◽  
Potential Yield ◽  
The Sanjiang Plain ◽  
Ecological Zones ◽  
The Future

Crop potential yields in cropland are the essential reflection of the utilization of cropland resources. The changes of the quantity, quality, and spatial distribution of cropland will directly affect the crop potential yields, so it is very crucial to simulate future cropland distribution and predict crop potential yields to ensure the future food security. In the present study, the Cellular Automata (CA)-Markov model was employed to simulate land-use changes in Northeast China during 2015–2050. Then, the Global Agro-ecological Zones (GAEZ) model was used to predict maize potential yields in Northeast China in 2050, and the spatio-temporal changes of maize potential yields during 2015–2050 were explored. The results were the following. (1) The woodland and grassland decreased by 5.13 million ha and 1.74 million ha respectively in Northeast China from 2015 to 2050, which were mainly converted into unused land. Most of the dryland was converted to paddy field and built-up land. (2) In 2050, the total maize potential production and average potential yield in Northeast China were 218.09 million tonnes and 6880.59 kg/ha. Thirteen prefecture-level cities had maize potential production of more than 7 million tonnes, and 11 cities had maize potential yields of more than 8000 kg/ha. (3) During 2015–2050, the total maize potential production and average yield decreased by around 23 million tonnes and 700 kg/ha in Northeast China, respectively. (4) The maize potential production increased in 15 cities located in the plain areas over the 35 years. The potential yields increased in only nine cities, which were mainly located in the Sanjiang Plain and the southeastern regions. The results highlight the importance of coping with the future land-use changes actively, maintaining the balance of farmland occupation and compensation, improving the cropland quality, and ensuring food security in Northeast China.

scholarly journals DOC concentrations and spectroscopic characteristics in surface runoff from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China

2012 ◽  
Vol 9 (6) ◽  
pp. 7919-7945
Author(s):  
L. L. Wang ◽  
C. C. Song ◽  
G. S. Yang
Keyword(s):  
Land Use ◽  
Surface Runoff ◽  
Rice Paddy ◽  
Sanjiang Plain ◽  
Natural Wetland ◽  
Artificial Wetland ◽  
The Sanjiang Plain ◽  
Wetland Ecosystems ◽  
Wetland Site ◽  
Spectroscopic Characteristics

Abstract. Dissolved organic carbon (DOC) is a significant component of carbon and nutrient cycling in fluvial ecosystems. Natural wetlands, as important DOC sources for river and ocean ecosystems, have experienced extensive natural and anthropogenic disturbances such as climate change, hydrological variations and land use change in recent years. In this study, we examined the concentrations and spectroscopic characteristics of DOC in surface runoff from contrasting wetlands along the lower Amur River Basin in the Sanjiang Plain, Northeastern China. Surface runoff from seven sites (two natural phialiform wetlands, three natural riparian wetland, one degraded wetland, and one artificial wetland i.e. rice paddy) were monitored during the growing seasons of 2009 and 2010. Surface runoff from the natural wetland sites exhibited a wide range of DOC concentrations (10.06–48.73 mg l−1) during the two-year sampling period. The specific ultraviolet absorbance (SUVA) and color values of DOC in surface runoff were also highly variable at different natural wetland sites. Our analysis also found that DOC values were significantly lower in the surface runoff at the artificial wetland site compared with those from surface runoff at the five natural wetland sites and one degraded wetland site (P < 0.01). The colour per carbon unit (C / C) ratio in surface runoff at the artificial wetland site was one to three times lower, while the E4 / E6 ratio (Abs465 / Abs665) was reduced by 42.07% to 55.36%, compared to those from runoff water at the five natural wetland sites. The C / C ratios in surface runoff at the natural wetland sites were higher than that from surface runoff at the degraded wetland, which in turn has greater values than that from surface runoff at the artificial wetland site. Meanwhile, the E4 / E6 ratio in the surface runoff from the artificial wetland was lower compared to that in surface runoff at the degraded wetland site (P < 0.05). This implies that disturbance to DOC concentrations and spectroscopic characteristics in surface runoff is stronger from natural wetland conversion to rice paddy land than that from wetland degradation. The dataset from this study can provide insightful points for understanding the underlying mechanisms of aquatic DOC dynamics from wetland ecosystems, and improve land use policy and management strategies in the future.

scholarly journals Impacts of Intensified Agriculture Developments on Marsh Wetlands

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Zhaoqing Luan ◽  
Demin Zhou
Keyword(s):  
Agricultural Development ◽  
Agricultural Landscape ◽  
Nature Reserve ◽  
Spatiotemporal Analysis ◽  
Sanjiang Plain ◽  
Natural Marsh ◽  
The Sanjiang Plain ◽  
Wetland Ecosystems ◽  
The Past ◽  
Remote Sensing Techniques

A spatiotemporal analysis on the changes in the marsh landscape in the Honghe National Nature Reserve, a Ramsar reserve, and the surrounding farms in the core area of the Sanjiang Plain during the past 30 years was conducted by integrating field survey work with remote sensing techniques. The results indicated that intensified agricultural development had transformed a unique natural marsh landscape into an agricultural landscape during the past 30 years. Ninety percent of the natural marsh wetlands have been lost, and the areas of the other natural landscapes have decreased very rapidly. Most dry farmland had been replaced by paddy fields during the progressive change of the natural landscape to a farm landscape. Attempts of current Chinese institutions in preserving natural wetlands have achieved limited success. Few marsh wetlands have remained healthy, even after the establishment of the nature reserve. Their ecological qualities have been declining in response to the increasing threats to the remaining wetland habitats. Irrigation projects play a key role in such threats. Therefore, the sustainability of the natural wetland ecosystems is being threatened by increased regional agricultural development which reduced the number of wetland ecotypes and damaged the ecological quality.

scholarly journals Ecological and economic aspects of rational use and protection of land resources in Ukraine

2017 ◽  
Vol 19 (79) ◽  
Author(s):  
T. B. Nahirniak ◽  
R. S. Grabovsky ◽  
M. R. Hrytsyna
Keyword(s):  
Land Use ◽  
Agricultural Development ◽  
Agricultural Land ◽  
Arable Land ◽  
The State ◽  
Integrated System ◽  
Economic Aspects ◽  
Land Protection ◽  
Rational Use ◽  
High Level

The current state of land use in Ukraine is characterized by high agricultural development and land cultivation. The predominant share in the total land stock of Ukraine is occupied by agricultural land (70.8% of the country's territory). Ukraine accounts for about 0.45% of the world land fund, while arable land occupies 2.4% of its world-wide area. According to resource-based indicators of land use Ukraine is also characterized by an extremely high level of development of living space and only about 8% of the territory can be attributed to anthropogenically unchanged. Ecological and economic aspects of land use include of rational land use, which characterizes the optimal involvement of all lands in economic circulation and their effective use for the main purpose, creation of favorable conditions for increasing productivity of agricultural land and obtaining from the unit of area the maximum amount of products at the lowest cost of labor and funds. The article substantiates that degradation of soils has its own characteristics, caused by various factors and processes. It is established that the practice of land use and the state of study of the above problems will require further study of the preconditions for the development of land degradation processes caused by the main factors: human economic activity and climatic and relief-ground conditions. The existing system of land protection in agriculture due to the influence of a number of natural and economic factors, as well as insufficient attention from the state does not ensure their rational use. Therefore, it is necessary to adhere to an integrated system of protection of agricultural land.

scholarly journals Crop Structure Changes Altered the Cropland Nitrogen Balance between 2005 and 2015 on the Sanjiang Plain, China

2018 ◽  
Vol 10 (11) ◽  
pp. 4011 ◽  
Author(s):  
Chunxia Yang ◽  
Hua Zheng ◽  
Binbin Huang ◽  
Ruonan Li ◽  
Zhiyun Ouyang ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Nitrogen Balance ◽  
Agricultural Development ◽  
Driving Forces ◽  
Sanjiang Plain ◽  
N Balance ◽  
The Sanjiang Plain ◽  
Use Efficiency ◽  
The Impact ◽  
N Use

Nitrogen (N) budgets have been computed in many countries at various scales to improve understanding of N-balance characteristics and to assess the environmental pollution risks of applying chemical fertilizer N. However, dynamic characteristics, driving forces, and potential soil fertility consequences related to cropland N balance have seldom been discussed, especially in regions with highly fertile soils and low N-use intensities. This study investigated the temporal and spatial characteristics of N balance, and the impact of agricultural development on the agro-ecosystems of the Sanjiang Plain, one of the largest producers of commodity food grains in China. County-level agricultural statistics at five-year intervals were used to calculate agricultural N balances, N surplus intensity, and N-use efficiency between 2005 and 2015. Agricultural development has brought about continual increases in cultivated land area, consumption of chemical fertilizers, and nitrogen use efficiency (NUE). Nitrogen surplus intensity decreased from 65.0 kg/ha in 2005 to 43.5 kg/ha in 2010, and to 22.2 kg/ha in 2015. However, NUE was >90% in 13 counties in 2015, and in 11 counties in 2010. In contrast, only 5 counties had NUE above 90% in 2005, which indicates that N from the soil was used by crops and soil fertility was gradually decreasing. The percentage change of crop area, namely, the increase in maize area percentage, contributed significantly to the increases in NUE. A judicious management of fertilizers that meets the nutrient needs of the crops and ensures agricultural sustainability on the Sanjiang Plain is therefore essential. The findings of this study emphasize the importance of assessing the impact of crop structure adjustment on soil fertility and nitrogen balance during agricultural development.

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