The spatiotemporal changes of marshland and the driving forces in the Sanjiang Plain, Northeast China from 1980 to 2016

Abstract

Background Wetland loss is a global concern due to its enormous ecosystem services. Marshland, a typical natural wetland, which is concentrated in the Sanjiang Plain, has undergone dramatic loss in the last several decades. The spatiotemporal changes in marshland were studied based on Landsat images of the Sanjiang Plain from 1980 to 2016 with the land use maps in 1980, 1995, 2000, 2005, 2010, and 2016 using land use dynamic degree and landscape indices. The driving forces of marshland loss, including biophysical factors, socio-economic factors, and land management, were analyzed with boosted regression trees (BRTs) methods. Results The area of marshland loss was 7372 km2, which accounted for 65.7% of the area of marshland in 1980; however, the paddy field area was expanded by 22,313 km2. The lost marshland was mainly converted to dry farmland (47.5%) and paddy field (47.2%) during 1980–2016. Both the landscape pattern of the study area and marshland became increasingly fragmented. The relatively important factors responsible for marshland loss were biophysical factors, socio-economic factors, and land management, which accounted for 65.2%, 25.5%, and 8.4%, respectively. The most important driving forces with high “relative influence” were “distance to river,” which accounted for 20.6% of the total variance explained. The “relative influence” of potential crop yield and ditch density reached 20.2% and 8.4%, respectively. Conclusion Significant land use changes have occurred in the Sanjiang Plain over the past 37 years, with characteristics of rapid paddy field expansion and drastic marshland loss. Meanwhile, marshland fragmentation continued to increase. Reclamation was the main reason for the large-scale marshland loss. Biophysical factors influenced the decisions regarding the locations of marshland loss. Moreover, climate factors (i.e., average annual precipitation and average annual temperature) also played an important role in marshland loss. These results can provide helpful knowledge for understanding the patterns and reasons for marshland loss and protecting and managing strategies for wetlands restoration.

The Driving Force of Urban Water Body Change in Chonburi Province, Thailand

“…An increase in population will result in a reduction 1.020 -4 km 2 (or 102 m 2 ) of water bodies. This result is consistent with the reports by Wu et al [31], Li et al [30], UN [27], Li et al [29] and the WWAP [53]. The WWAP [53] reported that population growth has led to a tripling of water withdrawal over the last 50 years while the UN [27] also indicated that the population influences water resource change due to the wide range of human needs, includeing food production, industrial development and domestic demand.…”

“…According to Li et al [29], human activities and terrain conditions had a negative effect on the water body area in the Jing-Jin-Ji region while climate and soil properties had a positive effect. Li et al [30] also revealed that from 1980-2016, there was a drastic loss of marshland (65.7%) due to rapid paddy field expansion in the Sanjiang Plain, Northeast China, influenced mainly by biophysical, socio-economic and land management factors. Wu et al [31] reported a decreasing trend in water bodies and an increasing trend in built-up area at Longfeng Wetland Natural Reserve in Daqing city.…”

Shrinking Habitats and Native Species Loss Under Climate Change: A Multifactorial Risk Assessment of China's Inland Wetlands

“…In the Songnen Plain, the expansion of agriculture during the past four decades has drastically lowered local groundwater levels, directly contributing to wetland shrinkage and salinization (Chen et al., 2018; Wang & Li, 2018). Similarly, in the Sanjiang Plain, rapid agricultural reclamation since the 1950s was identified as the primary driver of massive wetland loss, converting more than 70% of original wetlands into farmlands, while the contributions of climate change have been found growing (Li et al., 2020; Yan & Zhang, 2019).…”

Analysis of Climatic Basis for the Change of Cultivated Land Area in Sanjiang Plain of China

“…With the change of climate, planting systems and cultivated land layout in China vary in their regional climate adaptability, and the expansion of paddy fields in the cultivated land is prominent. Northeast China is a typical area of paddy field expansion among cultivated land (Ye et al, 2009;Li et al, 2020), and climate change is an important reason for the development of paddy fields in that area. However, the response characteristics of changed cultivated land use and distribution under different climatic factors and trends remain unclear, and the climatic basis for the change of both paddy field and dry land also needs more research.…”