Toward Best Management Practices for Ecological Corridors

Strategies for Restoring and Managing Ecological Corridors of Freshwater Ecosystem

Along with accelerating urbanization and associated anthropogenic disturbance, the structure and function of freshwater ecosystems worldwide are substantially damaged. To improve ecosystem health, and thus enhance the ecosystem security of the urban ecosystem, numbers of management approaches and engineering projects have been applied to mitigate the degradation of freshwaters. Nevertheless, there is still a lack of comprehensive and systematic research on the ecological corridor restoration of freshwater ecosystems; especially for Suzhou Grand Canal, one section of the world's longest and ancient Grand Canal which is inclined to severe ecosystem degradation. Through investigating the adjacent land use characteristics, habitat quality, vegetation cover, instream water quality, and habitat composition, we aimed to: (i) assess the water quality of the Suzhou Grand Canal; (ii) evaluate the ecological characteristics of the canal ecosystem; (iii) develop strategic countermeasures to restore the ecological corridors for the mitigation of ecological problems. The results demonstrated: a large built area, a smaller ecological zone, a low habitat quality and habitat connectivity, and a high degree of habitat fragmentation within the canal corridor, also a simplified instream habitat composition, and greater nutrient and COD concentrations in the surface water-especially in the upstream and midstream canal. All urbanization-induced multiple stressors, such as land use changes, altered hydrology, and the simplified riparian zone et al., contributed synergistically to the degradation of the canal ecosystem. To alleviate the ecosystem deterioration, three aspects of recommendations were proposed: water pollution control, watershed ecosystem restoration, and ecological network construction. Basically, building a comprehensive watershed ecological network-on the basis of associated ecosystem restoration, and the connection of multi-dimensional ecological corridors-would dramatically increase the maintenance of aquatic-terrestrial system biodiversity, and improve the regional ecological security pattern and watershed resilience toward stochastic future disturbances. This study contributes to the understanding of the ecological challenges and related causes of the canal ecosystem. The integrated strategy introduced in this study provides policymakers, water resource managers, and planners with comprehensive guidelines to restore and manage the ecological corridor of the canal ecosystem. This can be used as a reference in freshwater ecosystems elsewhere, to improve ecosystem stability for supporting the sustainable development of urban ecosystems.

River Ecological Corridor: A Conceptual Framework and Review of the Spatial Management Scope

Studying the spatial management scope of the river ecological corridor is a crucial step in effectively managing river health problems. For various purposes and needs, human beings intervene excessively in the river, resulting in the problems of unclear spatial scope, unclear ownership, and unreasonable functional utilization of the river ecological corridor. However, there is scarce research on the management scope of the river ecological corridor at present, and on the coordination relationship with territorial spatial protection planning. Therefore, in order to solve this key problem, this paper reviews and summarizes the current research status and development trends in terms of the concept, components, and other basic theories of the river ecological corridor, as well as relevant policy regulations. The relationship between the spatial scope of the river ecological corridor and the territorial spatial control line is analyzed, including the relationship with the river shoreline, aquatic ecological redline, “three control lines” and other control lines. Accordingly, this study reviewed the spatial management and control scope of the river ecological corridor. It also determined that the boundary line of the river shoreline management is the minimum line, the aquatic ecological redline, and the “three control lines” are the outermost boundary lines, in which the aquatic ecological redline has priority over other control lines. It also points out the thinking of determining the management scope in the protection and restoration of the river ecological corridor in the future. Our findings can provide a decision-making basis for the management of river ecological space.

Impacts of Zagreb’s Urban Development on Dynamic Changes in Stream Landscapes from Mid-Twentieth Century

Urban streams constitute a valuable form of multi-functional blue and green infrastructure (BGI) and can support urban development to generate ecosystem, social, and economic benefits. In global cities, planning for BGI enhancement contributes to climate change adaptation, ecosystem restoration, community health and wellbeing, improved quality of life, etc. This research aims to assess the dynamics of stream landscape change in Zagreb as well as the influence of urban development on the blue and green landscape and related urban values. The analysis of landscape features and their planning is conducted at the level of the stream system of the whole city of Zagreb and at the level of two stream sequences by superimposing spatial data from cartographic sources. By developing an urban planning-social-ecological approach to evaluation, monitoring, and management, a quantitative and qualitative trend in stream landscape changes is identified and indicators for detecting areas of critical urbanization pressure are established. This research confirms the trend of negative changes in the urban BGI, evident in the present state (interruption of open streams, and the reduction, fragmentation, and disconnection of blue and green landscape), as well as in the planned neglect (plans for further stream closures and reduction in public green areas). Stream landscape potential is emphasized as one of the greatest urban assets for improving the system of BGI, and areas needed for their prioritization in urban planning measures, directed towards an increase in multiple landscape values, are determined.

Predicting the potential suitable habitats of forest spices Piper capense and Aframomum corrorima under climate change in Ethiopia

Continuing climate change may cause shifts in the adaptive ranges of plant species. But this impact is less understood for many species in the tropics. Here, we examined the distribution of the current and future potential suitable habitats of two native forest spices Piper capense and Aframomum corrorima. We have used MaxEnt software to predict the current and future suitable habitats of these species. Two future climate change scenarios, that is, middle (Representative Concentration Pathway [RCP 4.5]) and extreme (RCP 8.5) scenarios for years 2050 and 2070, were used. A total of 60 and 74 occurrence data of P. capense and A. corrorima, respectively, and 22 environmental variables were included. The effects of elevation, solar radiation index (SRI) and topographic position index (TPI) on suitable habitats of these species were tested using linear model in R. Precipitation of the driest quarter, SRI and TPI significantly affect future suitable habitats of P. capense and A. corrorima. Furthermore, there are significant elevational shifts of suitable habitats for both species under future scenarios (P < 0.001). These novel suitable habitats are located in moist Afromontane and Combretum-Terminalia vegetations. Our results suggest that conservation planning for these species should consider climate change factors including assisted migration.

From a Hard to Soft Approach for Flood Management in the Vietnamese Mekong Delta: Integrating Ecological Engineering for Urban Sustainability in My Tho City

Flooding is one of the leading challenges faced by delta cities in the world. Flood risk management using flood control infrastructure (FCI) is a popular solution to prevent flood damage; however, this is receiving enormous criticism due to its negative impacts on urban ecosystems. Recently, there have been new approaches to flood risk management that gradually shifted the focus away from FCI, such as ecological infrastructure (EI) based approaches. However, the conventional thinking that cities cannot be safe without FCI seems an immutable one, especially in developing countries. This study firstly assessed human–river interaction in direct relation to FCI and outlined the limitations of FCI. Then, an urban ecology research model was used to conduct a case study in the Vietnamese Mekong Delta (VMD), in which the interaction between factors, including riverine urbanization, FCI formation dynamics, the changing hydrological regime, flood risk, and riverine ecosystem degradation were evaluated. Due to the dynamism and complexity of the interactions between humans and rivers at the VMD, this study attempts to demonstrate that building the ability to adapt to flood risks based on EI will have a crucial role in enhancing the sustainability of delta cities. Through a case study in My Tho City (MTC) a flood resilience management scenario for a riverine urban area along the Mekong River was developed to discuss the role of EI in flood risk reduction and the restoration of riverine native ecosystems. The findings from this study suggests that EI should be considered as an effective and indispensable design tool for the conservation of riparian ecological corridors and public open spaces—which is a major challenge for urban areas in the context of increasing climate change impacts in the VMD.

Carnivores and their prey in Sumatra: Occupancy and activity in human-dominated forests

Understanding the effect of anthropogenic disturbance, and its interaction with carnivores and their prey, is crucial to support the conservation of threatened carnivores, particularly in rapidly changing landscapes. Based on systematic camera-trap sampling of four protected areas in Riau Province of central Sumatra, we assessed the habitat occupancy and spatiotemporal overlap between people, potential carnivore prey, and four threatened species of medium-sized or large carnivores: Sumatran tigers (Panthera tigris sumatrae), Malayan sun bears (Helarctos malayanus), dholes (Cuon alpinus), and Sunda clouded leopards (Neofelis diardi). To assess spatial overlap of target species, we used single-species occupancy models and applied a Species Interaction Factor (SIF) to conditional two-species occupancy models. We also used kernel density estimation (KDE) to assess temporal overlap among these species. Our habitat use models showed that altitude (elevation) strongly influenced the occupancy of all large carnivores and potential prey species. Except for Sunda clouded leopards, the occurrence of large carnivore species was positively related to the spatial co-occurrence of humans (SIF > 1). In addition, we found that sun bears and dholes both exhibited high spatial overlap with tigers, and that sun bears alone exhibited high temporal overlap with people. Our findings contribute to an improved understanding of the contemporary ecology of carnivores and their prey in rapidly changing, southeast Asian landscapes. Such knowledge is important to the conservation and recovery of large carnivores in conservation hotspots that are increasingly dominated by humans across Sumatra, as well as globally.

Ecological Security Pattern Construction in Karst Area Based on Ant Algorithm

Constructing the ecological security pattern is imperative to stabilize ecosystem services and sustainable development coordination of the social economy and ecology. This paper focuses on the Karst region in southeastern Yunnan, which is ecologically fragile. This paper selects the main types of ecosystem services and identifies the ecological source using hot spot analysis for Guangnan County. An inclusive consideration of the regional ecologic conditions and the rocky desertification formation mechanism was made. The resistance factor index system was developed to generate the basic resistance surface modified by the ecological sensitivity index. The Ant algorithm and Kernel density analysis were used to determine ecological corridor range and ecological restoration points that constructed the ecological security pattern of Guangnan County. The results demonstrated that, firstly, there were twenty-three sources in Guangnan County, with a total area of 1292.77 km², accounting for 16.74% of the total. The forests were the chief ecological sources distributed in the non-Karst area, where Bamei Town, Yangliujing Township and Nasa Town had the highest distribution. Secondly, the revised resistance value is similar to “Zhe (Zhetu Township)-Lian (Liancheng Town)-Yang (Yangliujing Township)-Ban (Bambang Township)”. The values were lower in the north and higher in the south, which is consistent with the regional distribution of Karst. Thirdly, the constructed ecological security pattern of the “Source-Corridor-Ecological restoration point” paradigm had twenty-three ecological corridors. The chief ecological and potential corridor areas were 804.95 km² and 621.2 km², respectively. There are thirty-eight ecological restoration points mainly distributed in the principal ecological corridors and play a vital role in maintaining the corridor connectivity between sources. The results provide guidance and theoretical basis for the ecological security patterns construction in Karst areas, regional ecologic security protection and sustainable development promotion.