The Development of Dynamic Spatial Models for Landscape Ecology: A Review and Prognosis

Landscape Connectivity Analysis and Optimization of Qianjiangyuan National Park, Zhejiang Province, China

As natural ecosystems in most parts of the world come under increasing human influence, fragmentation is becoming the major driving factor of the global biodiversity crisis. Therefore, connectivity between habitat patches is becoming even more important. China began building national parks with the primary purpose of protecting nationally representative natural ecosystems and maintaining the integrity of their structure, processes and functions. Research is necessary to improve the internal connectivity of national parks and to propose suggestions for existing functional zoning and biological corridors. In this study, Qianjiangyuan National Park was selected as an example park, and landscape fragmentation was evaluated exponentially and simulated visually. The habitat characteristics of protected species in the region, morphological spatial pattern analysis and the delta of the probability of connectivity were used together to identify key habitat patches and their importance levels in the study area. Potential habitat corridors in the region were then obtained using least-cost path analysis and gravity modeling methods based on the distribution of key habitat and the migration costs of target species. The results of this study show that the disturbed landscape of the study area is dominated by tea plantations and drylands, with central roads being an important factor affecting the overall landscape connectivity. In terms of the distribution of key habitat patches, the mountains have a high value. In terms of area, their size is not directly proportional to their importance for maintaining landscape connectivity in the region, but large area patches are generally of higher importance. In terms of distance, key habitats that are closer to each other have a stronger correlation and a greater possibility for species migration. Combined with the functional zoning of Qianjiangyuan National Park, the setting of strictly protected areas and recreational areas is reasonable, and traditional use areas and ecological conservation areas could be appropriately adjusted according to the distribution of key habitats. The important corridor in the middle of the ecological conservation area is crucial for the overall connectivity of the national park, and the connectivity between strict protected areas will depend on successful protection of the ecological conservation area.

Connectivity assessment and prioritization of urban grasslands as a helpful tool for effective management of urban ecosystem services

Urban grasslands are usually managed as short-cut lawns and have limited biodiversity. Urban grasslands with low-intensity management are species rich and can perform numerous ecosystem services, but they are not accepted by citizens everywhere. Further, increasing and/or maintaining a relatively high level of plant species richness in an urban environment is limited by restricted plant dispersal. In this study, we examined the connectivity of urban grasslands and prioritized the grassland patches with regard to their role in connectivity in an urban landscape. We used high-resolution data from a land use system to map grassland patches in Wrocław city, Silesia, southwest Poland, Central Europe, and applied a graph theory approach to assess their connectivity and prioritization. We next constructed a model for several dispersal distance thresholds (2, 20, 44, 100, and 1000 m), reflecting plants with differing dispersal potential. Our results revealed low connectivity of urban grassland patches, especially for plants with low dispersal ability (2–20 m). The priority of patches was correlated with their area for all dispersal distance thresholds. Most of the large patches important to overall connectivity were located in urban peripheries, while in the city center, connectivity was more restricted and grassland area per capita was the lowest. The presence of a river created a corridor, allowing plants to migrate along watercourse, but it also created a barrier dividing the system. The results suggest that increasing the plant species richness in urban grasslands in the city center requires seed addition.

Spatial influence of ecological networks on land use intensity

Rapid urbanization resulted in widespread urban expansion and the fragmentation and isolation of large-scale ecological sources. Ecological sustainability has propelled the popularity and implementation of intensive land use programs worldwide, in China particularly. In this study, we explored the spatial spillover effect through ecological networks on intensive urban land use and the underlying driving mechanism using the Wuhan urban agglomeration as the case study area. First, we comprehensively measured land use intensity (LUI) from three dimensions: input, output, and landscape aggregation. Second, ecological sources were identified on the basis of land use maps, and ecological networks were constructed using the "minimum cumulative resistance" model. Then, the "gravity model" was applied to measure the spatial interaction among ecological sources and to construct spatial weight matrices for spatial modeling. Lastly, we devised a spatial Durbin model using the designed "ecological" spatial weight matrices to examine the influencing factors and the potential spatial interactions or constraints. The results showed that the average values of LUI in 2017 were almost 70 times higher than that in 2005 and the Jianghan District had the highest increment (91 times) from 2005 to 2017. LUI was primarily driven by socioeconomic development. Gross domestic product and proportion of tertiary sector exerted positive influences, whereas agricultural output value exhibited a negative effect on LUI in 2005 and 2017. A positive spatial autocorrelation of LUI was observed at the county level, and the spatial spillover effect was confirmed through ecological networks during intensive land use, indicating that ecological spatial influence is an important factor in explaining LUI. The findings help in exploring the spatial influence through ecological networks on LUI at the regional level and provide references for formulating relevant policies to achieve the ecological security of terrestrial ecosystems and coordinated and balanced regional sustainable development.

Spread of white-nose syndrome on a network regulated by geography and climate

Wildlife and plant diseases can reduce biodiversity, disrupt ecosystem services and threaten human health. Emerging pathogens have displayed a variety of spatial spread patterns due to differences in host ecology, including diffusive spread from an epicentre (West Nile virus), jump dispersal on a network (foot-and-mouth disease), or a combination of these (Sudden oak death). White-nose syndrome is a highly pathogenic infectious disease of bats currently spreading across North America. Understanding how bat ecology influences this spread is crucial to management of infected and vulnerable populations. Here we show that white-nose syndrome spread is not diffusive but rather mediated by patchily distributed habitat and large-scale gradients in winter climate. Simulations predict rapid expansion and infection of most counties with caves in the contiguous United States by winter 2105-2106. Our findings show the unique pattern of white-nose syndrome spread corresponds to ecological traits of the host and suggest hypotheses for transmission mechanisms acting at the local scale.