Effects of landscape evolution stages on soil properties distribution in Yancheng National Nature Reserve, China

10.31195/ejejfs.422791 Eurasian Journal of Forest Science 2018 6(3): 15-24 http://dergipark.gov.tr/ejejfs Effects of landscape evolution stages on soil properties distribution in Yancheng National Nature Reserve, China Yufeng Li1, Juan Wang2 and Hongyu Liu1,* 1* Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Key Laboratory of Virtual Geographic Environment (Ministry of Education), State Key Laboratory Cultivation Base of Geographical Environment Evolution, College of Geographical Science, Nanjing Normal University, Nanjing 210023, China. 2 School of Urban and Planning, Yancheng Teachers University, Yancheng 224007, China. Corresponding author: Abstract A typical wetland in the core area of Yancheng National Nature Reserve was chosen as study area. Using three periods of remote sensing images in 1992, 2002 and 2011, different successional stages of landscape have been discerned. And then by employing a space-for-time substitution approach, related environmental factors of soil was analyzed. The analysis results showed that the landscape types and its successional time were the important factors that influenced the spatial distributions of soil characteristic. The detailed results revealed: (1) The Spartina marsh succession time was longer, more reduction effect of soil water and salt content, more with the accumulation effect on soil nutrients; (2) The Suaeda marsh succession time was longer, more accumulation of soil water and salt content, more with the weakening effect on soil nutrients; (3) The moisture, salinity of soil decreased more and more, soil nutrient increased more and more as the grass marsh existed longer time. This study could help us to evaluate the degradation of wetland and the effect of wetland restoration, as well as to help us to achieve the balance between utilization and reservation. Keywords: Landscape evolution, coastal wetland, space-for-time substitution, soil properties, Yancheng National Nature Reserve Introduction Yancheng National Nature Reserve (YNNR) is one of the most important landscape evolution of China and one of the most complex typical muddy coastal wetlands in the world ecosystem type. The YNNR is one of the world’s major winter habitats for red-crowned cranes. It is also a stop-over site for over 300 species of migratory birds from Northeast Asia and Australia (Zhu et al. 2004). So, the habitat of those birds need to be focused, especially the change of its landscape. Currently, studies into the evolution process of coastal wetlands, ecosystem health and reconstruction and ecosystem service values are at the forefront of national wetland research (Sean 2002; Roychoudhury et al. 2003; Zhang et al. 2013). The YNNR has attracted attention from scholars since the 1980s (Zhu and Xu 1982; Zhu et al. 2004) for studies into topography, sedimentation, hydrology, ecology, sustainable development and evolution of landscape (Zhang 1986; Zhang 1991; Shen et al. 2006). The study of landscape evolution which related to ecological process in YNNR is sorely lacked. Although some studies noted the effects of hydrogeomorphologic processes on wetland landscape in coastal area (Gao et al. 2005; 15 Eurasian Journal of Forest Science – Effects of landscape evolution stages by Li et al. 2018 6(3) Yao et al. 2009), research results in the relationships between soil processes and the evolution of landscape are very limited. On the issues of landscape evolution, most of researches focus on identifying the landscape evolution of time and space dynamic using remote sensing methods (Clarkson 1998; Odland 2002; Bender 2005), and landscape evolution is one of the main factors that control the soil properties (Gamboa and Galicia 2011). Vegetaion changes in the landscape can make effective on soil charicteristics and soil charicteristics as a reaction will be on vegetation. Vegetation changes under the forces of nature (not due to human activity) in landscape can be regarded as landscape evolution. Although many studies have focused on the effect of different landscape evolution on the soil properties, the effects of landscape conversion on the soil properties are not fully understood due to the variability of tillage systems and the shortage of historical soil data (Pellegrino et al. 2011). It is generally accepted that the dynamics of landscape is best studied by long-term observations and experiment (Gosz 1996). With regard to soil data shortages, remote sensing, and geographical information system are typically used to identify the changes in landscape and soil properties (El-Shikha et al. 2007), as well as the spatial variability of soil properties in ecosystems (Grunwald et al. 2007). Appropriate space-for-time substitution (SFT) can aid planning of observations and experiments for further study. The vegetation landscape-soil system, a part of the coastal ecosystem, is a dramatically dynamic and developmental process (Ouyang et al. 2013). The soil develops continuously to reach a balance that relates with vegetation climax along the vegetation landscape succession (Zhang et al. 1990). A quantitative investigation of the soil characteristic evolution and its mechanism in terms of landscape evolution is vital to the study of the development tendency of the coastal system (Li et al. 2013). The core area of YNNR was chosen as the study area to provide a scientific foundation for constructing the eco-environment and rehabilitating the water storing and regulating capacity of the soil. The intact series in the natural landscape evolution on coastal area can be found in this area. The soil characteristics at different landscape evolution stages can be analyzed by SFT in YNNR. Through the collection and analysis of soil samples, the relationship of the process of landscape succession and soil factors can be obtained in YNNR. It provides an in-depth understanding and the basic reference of the coastal wetland ecosystem in the process of succession. Materials and methods Study area The Yancheng coastal marshes are located in the coastal zone of Jiangsu Province, East China (Fig.1). In 1983, YNNR was established to help conserve rare bird species and their habitats. As the marsh area has a rich biodiversity, YNNR was accepted as a member of the UNESCO Man and Biosphere Reserve network in 1993 and was admitted as Northeast Asian Crane Reserve Network Site in 1997 and as an East Asia-Australian Migratory Shorebirds Network Site in 1999. The coast of YNNR is accreting annually with the mudflats moving about 50 to 200 meters seawards per year in the study area (Wang et al. 2006). Its original landscape comprises coastal salt marsh, so the variety of vegetation is poor and dominated by salt tolerant plants. The vegetation landscape had a typical landward succession sere type (Wan et al. 2001): (1) the pioneer species Spartina alterniflora dominates the elevated part of the intertidal zone; (2) a Sua (...truncated)