Effects of Water Regime on Spring Wetland Landscape Evolution in Poyang Lake between 2000 and 2010

Abstract

Abstract:Water regime was one of the most important driving factors in the formation of wetland landscape and the growth and distribution pattern of wetland vegetation. Currently, research on the relationship between wetland landscape and water regime was mostly focused in autumns and winters in Poyang Lake, and lack of research in springs. Based on the nine high-resolution spring remote sensing images during 2000-2010, the classification characteristics of wetland landscape and spatial distribution pattern of vegetation and their succession trends in Poyang Lake were studied through quantitative interpretation technology and multivariate statistical analysis. Combined with water level fluctuations characteristics of the five monitoring hydrological stations (i.e., Hukou, Xingzi, Duzhan, Tangyin and Kangshan) at the Poyang Lake, the inter-annual and intra-annual water level variations of Poyang Lake were analyzed. The study was aimed to investigate the quantitative effects of water regime on the spring wetland landscape and spatial distribution pattern of vegetation and their succession trends in Poyang Lake. The results showed that: (1) the maximum scope of water levels of the five monitoring stations varied from 8.5 m to 13.57 m, and the water level of Poyang lake showed a downward trend, declining at an average rate of 0.16 m per year during 2000-2010; (2) the total area of the 10 types of the landscapes did not change significantly, which was always maintained at about 3026 km 2 and the total area of vegetation coverage showed increasing trend during 2000-2010 in Poyang Lake, with a maximum area in 2008 and a minimum area in 2010; (3) The water level change was consistent with the area of the lake water, and was inconsistent with the areas of the mudflat, vegetation and land-water transition zone. The highest linear fitting degree with water level was the area of the land-water transition zone, followed by the lake water and vegetation. The results were helpful to further explore the eco-hydrology process and its trend at Poyang Lake wetland, a scientific reference for the maintenance of stable ecosystem functions of the seasonal freshwater lake wetland.

Changes in Ecosystem Service Value in the 1 km Lakeshore Zone of Poyang Lake from 1980 to 2020

“…Among them, agricultural land had the highest change in area, increasing at a rate of 9.57/year, followed by wetlands, decreasing at the rate of 8.08/year. it is worth noting that the wetlands area in the lakeshore zone of Poyang Lake has continued to decrease from 1990 to 2015, which is consistent with some current findings [44][45][46].…”

Evolution of Ecological Patterns of Poyang Lake Wetland Landscape over the Last One Hundred Years Based on Historical Topographic Maps and Landsat Images

“…When the water level is high, there will be "a flood", and when the water level is low, there will be "one line of water". Rivers such as Ganjiang River, Fuhe River, and Xinjiang River flow into Poyang Lake from south to north, and form a large area of shoals and wetlands [45]. Since the population and major industries and agriculture of Jiangxi Province are concentrated in the Poyang Lake Plain and its surrounding areas, as well as Nanchang, the capital city of Jiangxi Province, is less than 100 km away from the main lake area of Poyang Lake.…”

Role of Flooding Patterns in the Biomass Production of Vegetation in a Typical Herbaceous Wetland, Poyang Lake Wetland, China

“…Specifically, over 80% of its vegetated area is covered by Carex spp., and the left 20% is mainly covered by Phragmites spp. (You et al, 2017;Dai et al, 2019). In the flood seasons, almost all floodplains are inundated, and the coverage area of the water surface reaches more than 3,000 km 2 .…”

“…Poyang Lake is the largest freshwater lake and area of alluvial wetlands in China (You et al, 2017;Wan et al, 2018). The extensive and prolonged summer flooding has characterized the water regime of the wetland (Liu Y.…”