Wetland changes and mangrove restoration planning in Shenzhen Bay, Southern China

Abstract

Mangrove forests and associated gei wai (excavated ponds used for shrimp and fish farming) provide important ecosystem services in Shenzhen Bay. Much of the mangrove and gei wai wetlands, however, have been lost because of intensified human activities in the past 30 years. Using five-phase remote-sensing images, we describe the recent history of the spatial-temporal dynamics for the wetlands in the bay. From 1986 to 2007, mangrove area increased from 1.8 to 4.8 km 2 , while the area of gei wai decreased from 36.6 to 17.2 km 2 . Reclamation of gei wai mainly occurred in western and northern Shenzhen Bay, and changed the tidal water environment. The bay has five typical mangrove communities: Avicennia marina ? Kandelia candel ? Aegiceras corniculatum, Kandelia candel ? Aegiceras corniculatum ? Acanthus ilicifolius, Bruguiera gymnorrhiza ? Excoecaria agallocha, Aegiceras corniculatum, and Sonneratia apetala ? Sonneratia caseolaris. The distribution of these communities and their dominant species in the bay exhibit a spatial pattern and temporal (successional) sequence. We describe a mangrove restoration program based on the mangrove successional sequence and the interaction of mangrove and gei wai in the bay. We have planned six mangrove protection and restoration projects in closed areas, semiclosed areas, and open areas to reconstruct the ecological integrity of the entire Shenzhen Bay.

Quantitative Estimation of the Velocity of Urbanization in China Using Nighttime Luminosity Data

“…A few but notable observations commonly show geographically explicit consequences of accelerating urban growth in China's cities: for instance, spatially shrinking and fragmentizing lake wetlands within Wuhan [33], gradually disappearing mangrove swamps with the expansion of urban areas to the shoreline in Shenzhen [34], changes in nest features of Magpies along the urban-rural gradient in Hangzhou [35], human settlement density-related fluctuations in baseline hormone levels in Beijing [36], decreased macroinvertebrate richness in stream habitats in relation to urban development level in the Qiantang River [37], and altered surface albedo owing to rapid urbanization [38]. All these observed changes and shifts seem to geographically coincide well with the dispersal of urban activities.…”

Evaluating the Effectiveness of Conservation on Mangroves: A Remote Sensing-Based Comparison for Two Adjacent Protected Areas in Shenzhen and Hong Kong, China

“…In the last decade, local governments invested billions of dollars to protect wetlands and to restore mangrove ecosystems while maintaining economic and social development [68]. However, it appears that restoration means planting or replanting [6].…”

“…Changes in the MPMNR's mangroves have shown three aspects of successful restoration: (1) drastically increased mangrove area ( Figures 3 and 4); (2) elevation and slope, soil and water pH, soil texture, salinity, wave energy, and nutrient concentration) are appropriate [3,6]. The term "restoration" has been adopted in the core zone of the MPMNR to specifically mean the "maintenance of natural processes" (ecological restoration), which aims to return mangrove ecosystems to a natural succession condition by not disturbing its living condition [68]. In fact, in 2001, the Drainage Services Department (DSD) received flooding complaints in the Yuen Long area and expressed concern that outgrowth of the mangrove forest at the Shan Pui River mouth might eventually undermine the channel's flood discharge capacity in the Yuen Long area.…”

Ecological Landscape Planning and Design Strategies for Mangrove Communities (Hara Forests) in South-Pars Special Economic Energy Zone, Asalouyeh- Iran

“…In landscape ecology, the relationships between structures and components are more important than the individual components, these relations can be either vertical (into a spatial unit) or horizontal (between spatial units) ( Figure 6). Most coastal development planning involves mangrove restoration and management, and rehabilitation or restoration of mangrove ecosystems has been reviewed (Hai Ren et al, 2010). Here, according to the domain of human perception are presented strategies for planning and ecological design of mangrove communities and habitats of Nayband Bay area (and Table 1; Figure 7 ).…”