Development of Xiong'an New District (XND) is integral to the implementation of the Beijing-Tianjin-Hebei (BTH) Integration Initiative. It is intended to ease the non-capital functions of Beijing, optimize regional spatial patterns, and enhance ecosystem services and living environment in this urban agglomeration. Applying multi-stage remote sensing (RS) images, land use/cover change (LULC) data, ecosystem services assessment data, and high-precision urban land-cover information, we reveal the regional land-cover characteristics of this new district as well as across the planned area of the entire BTH urban agglomeration. Corresponding ecological protection and management strategies are also proposed. Results indicated that built-up areas were rapidly expanding, leading to a continuous impervious surface at high density. Urban and impervious surface areas (ISAs) grew at rates 1.27 and 1.43 times higher than that in 2000, respectively, seriously affecting about 15% area of the sub-basins. Construction of XND mainly encompasses Xiongxian, Rongcheng, and Anxin counties, areas which predominantly comprise farmland, townships and rural settlements, water, and wetland ecosystems. The development and construction of XND should ease the non-capital functions of Beijing, as well as moderately control population and industrial growth. Thus, this development should be included within the national 'sponge city' construction pilot area in early planning stages, and reference should be made to international low-impact development modes in order to strengthen urban green infrastructural construction. Early stage planning based on the existing characteristics of the underlying surface should consider the construction of green ecological patches and ecological corridors between XND and the cities of Baoding, Beijing, and Tianjin. The proportion of impervious surfaces should not exceed 60%, while that of the core area should not exceed 70%. The development of XND needs to initiate the concept of 'planning a city according to water resource amount' and incorporate rainwater collection and recycling.

As a hot spot in geography, ecology and related disciplines, ecosystem services have been playing a vital role in bridging the human society with the ecosystem. A deep understanding of the relationship among ecosystem services is a critical enabling factor for sustainable management and decision-making in multiple ecosystem services, in turn realizing the dual goals of economic development and ecological protection and thus contributing to the overall wellbeing of human. Through a systematic review of the concept of ecosystem service trade-offs, this article explores their characteristics in terms of spatial scales, temporal scales and reversibility, considering human's wellbeing at different levels as the ultimate goal of ecosystem service trade-offs and ecological compensation as a baseline method of protection in trade-offs. Such ecosystem services trade-offs are expressed by quantitative indexing and integrated modelling. While such trade-offs and synergies among ecosystem services could present significant variations by spatial and temporal scales, scenario simulation and multi-objective analysis are effective ways to support decision-making in ecosystem service trade-offs. Based on these findings, the multi-scale correlation of ecosystem service trade-offs, the flow of ecosystem service based on telecoupling, and the consumption and compensation of ecosystem services are identified to be the main directions for future research on ecosystem service trade-offs.

Beijing, as the political, communicational, cultural, and technological center of China, has been experiencing rapid urban expansion in recent years. This fast urbanization resulted in greater demands for ecosystem services from peri-urban ecosystems. Based on emergy analysis and using impact matrix, this study took the urban ecological conservation area (ECA) of Beijing as an example to evaluate the ecosystem services flows and the level of dependence between natural and urban systems. In terms of ecosystem types, results show that forest ecosystem contributes the most to ecosystem service provision in ECA, which represents 79.7% of total ecosystem services emergy in 2012. Meanwhile, cropland and aquatic ecosystems account for 19.7% and 0.6%, respectively. From the perspective of ecosystem services types, biomass production and water retention are the two dominative service types provided by forest ecosystem, accounting for 40.4% and 35.8% of forest ecosystem services emergy respectively. Food supply is the most significant emergy component in cropland ecosystem, which represents 70% of cropland ecosystem service emergy. Water supply, flood storage and aquatic product supply are the three most important emergy components in aquatic ecosystem, which account for 35.1%, 28.6% and 28.2% of the total aquatic emergy respectively. Results of emergy impact matrix suggest that forest biomass, soil water, groundwater and cropland biomass are the four vital providers of ecosystem services to urban system. At the temporal scale, results demonstrated that forest and aquatic ecosystems played more and more significant roles in water retention and water supply while cropland ecosystems became less and less important in food supply from 2004 to 2012. Urban system also transformed from a positive influencing to a passive receiving factor of ecosystem services in this period. Accordingly, more attention should be paid to conservation of forest and aquatic ecosystems in future urban planning in order to achieve better ecosystem service provision.