Land use profoundly changes the terrestrial ecosystem and landscape patterns, and these changes reveal the extent and scope of the ecological influence of land use on the terrestrial ecosystem. The study area selected for this research was the middle reaches of the Heihe River. Based on land use data (1986, 2000, and 2014), we proposed an ecological risk index of land use by combining a landscape disturbance index with a landscape fragility index. An exponential model was selected to perform kriging interpolation, as well as spatial autocorrelations and semivariance analyses which could reveal the spatial aggregation patterns. The results indicated that the ecological risk of the middle reaches of the Heihe River was generally high, and higher in the northwest. The high values of the ecological risk index (ERI) tended to decrease, and the low ERI values tended to increase. Positive spatial autocorrelations and a prominent scale-dependence were observed among the ERI values. The main hot areas with High-High local autocorrelations were located in the north, and the cold areas with low-low local autocorrelations were primarily located in the middle corridor plain and Qilian Mountains. From 1986 to 2014, low and relatively low ecological risk areas decreased while relatively high risk areas expanded. A middle level of ecological risk was observed in Ganzhou and Minle counties. Shandan County presented a serious polarization, with high ecological risk areas observed in the north and low ecological risk areas observed in the southern Shandan horse farm. In order to lower the eco-risk and achieve the sustainability of land use, these results suggest policies to strictly control the oasis expansion and the occupation of farmland for urbanization. Some inefficient farmland should transform into grassland in appropriate cases.

https://www.mdpi.com/2071-1050/8/6/536/pdf

Dynamic Ecological Risk Assessment and Management of Land Use in the Middle Reaches of the Heihe River Based on Landscape Patterns and Spatial Statistics

Spatiotemporal patterns and modifiable areal unit problems of the landscape ecological risk in coastal areas: A case study of the Shandong Peninsula, China

Applied with remote sensing, GIS, and mathematical statistics, the spatial-temporal evolution characteristics of urbanization expansion of Yantai city from 1974 to 2009 was studied. Based on landscape pattern metrics and ecological risk index, the landscape ecological risk from the landscape pattern dynamics was evaluated. The results showed that the area of urban land increased by 189.77 km(2) with average expansion area of 5.42 km(2) y(-1) from 1974 to 2009. The urbanization intensity index during 2004-2009 was 3.92 times of that during 1974-1990. The land use types of urban land and farmland changed greatly. The changes of landscape pattern metrics for land use patterns indicated that the intensity of human activities had strengthened gradually in study period. The landscape ecological risk pattern of Yantai city shaped half-round rings along the coastline. The ecological risk index decreased with increase of the distance to the coastline. The ratio of high ecological risk to subhigh ecological risk zones in 2009 was 2.23 times of that in 1990. The significant linear relationship of urbanization intensity index and regional ecological risk indicated that the anthropological economic activities were decisive factors for sustainable development of costal ecological environment.

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Effects of Urbanization Expansion on Landscape Pattern and Region Ecological Risk in Chinese Coastal City: A Case Study of Yantai City

Land use changes associated with urbanization may increase ecological risk and subsequent geohazard risk. Africa is particularly vulnerable at preset as, since 2005, the highest rates of rapid urbanization-associated forest degradation have occurred there. On August 14, 2017, a compound geohazard in Freetown, Sierra Leone, caused thousands of fatalities and destroyed hundreds of houses. Land use change is considered the main factor contributing to geohazard initiation. Here, we use Freetown as a case study to quantitatively assess the magnitude of the increase in ecological risk associated with land use changes. To achieve the aim, satellite images are used in the case study area from 2007 to 2017, the data are integrated into a geographic information system. A series of indices are then used based on the processed images to describe land use and ecological risk, including dynamic index, trend and state index, and ecological risk index. The results show that Freetown experienced a rapid urbanization process, together with an unbalanced increase in urban land and complex conversion of bare and grass land, from 2007 to 2017. Significantly degenerated forest was converted into urban land (2.77%), bare land (6.47%), and grassland (10.27%), while the ecological risk level increased from low to high. The ecological risk in the affected area of geohazard is found higher than that of the surrounding mountainous area. It indicates that vegetation may reduce the risk of disaster. This result is helpful for the trade-off between urban development and ecological protection and rational urban planning. For disaster resilience and sustainable development of Freetown, and also other rapidly urbanizing cities in mountainous areas, ecological protection must be incorporated into development planning.

Ecological risk resonance of urbanization and its effect on geohazard disaster: the case of Freetown, Sierra Leone

Integrating Ecosystem Health and Services for Assessing Ecological Risk and its Response to Typical Land-Use Patterns in the Eco-fragile Region, North China

By using RS and GIS technology, the ecological risk index (ERI) was constructed based on the analysis of land use change and structural characteristics in urbanization watershed of Songhua River in Harbin section. Afterwards, the spatial distribution and change characteristics maps of ERI obtained by using block Kriging were analyzed to reveal the spatial and temporal evolution characteristics, change rules and formation mechanisms of ecological risk based on land use under the background of urbanization, and to minimize land use risk during urbanization process. The results showed that during the past 18 years, moderate ecological risk level was major, while proportion of high ecological risk was the lowest, and the area of higher and lower ecological risk region changed most greatly; high and higher ecological risk were focused on urban region and the transition zone from urban to suburban region, while low and lower ecological risk mainly distributed in forestland with higher vegetation coverage, water bodies, grassland, shrub land and so on. Meanwhile, the transition zone from high to low ecological risk was very obvious. In addition, ecological risk became slightly worse in some region due to the transformation from cropland to residential and urban land, while it became slightly better in other regions because of the transformation from cropland to forestland; the center of gravity in lower ecological risk region shifted most greatly, while the shift was the smallest in high ecological risk region, namely 12.31 and 0.57 km respectively.

Study on Ecological Risk of Land Use in Urbanization Watershed Based on RS and GIS:A Case Study of Songhua River Watershed in Harbin Section

Abstract Habitat loss and fragmentation are widely acknowledged as the main driver of the decline of giant panda populations. The Chinese government has made great efforts to protect this charming species and has made remarkable achievements, such as population growth and habitat expansion. However, habitat fragmentation has not been reversed. Protecting giant pandas in a large spatial extent needs to identify core habitat patches and corridors connecting them. This study used an equal‐sampling multiscale random forest habitat model to predict a habitat suitability map for the giant panda. Then, we applied the resistant kernel method and factorial least‐cost path analysis to identify core habitats connected by panda dispersal and corridors among panda occurrences, respectively. Finally, we evaluated the effectiveness of current protected areas in representing core habitats and corridors. Our results showed high scale dependence of giant panda habitat selection. Giant pandas strongly respond to bamboo percentage and elevation at a relatively fine scale (1 km), whereas they respond to anthropogenic factors at a coarse scale (≥2 km). Dispersal ability has significant effects on core habitats extent and population fragmentation evaluation. Under medium and high dispersal ability scenarios (12,000 and 20,000 cost units), most giant panda habitats in the Qionglai mountain are predicted to be well connected by dispersal. The proportion of core habitats covered by protected areas varied between 38% and 43% under different dispersal ability scenarios, highlighting significant gaps in the protected area network. Similarly, only 43% of corridors that connect giant panda occurrences were protected. Our results can provide crucial information for conservation managers to develop wise strategies to safeguard the long‐term viability of the giant panda population.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/ece3.8628

Identifying core habitats and corridors for giant pandas by combining multiscale random forest and connectivity analysis

Protected areas are considered the cornerstone of endangered wildlife conservation. However, quantified conservation potentials and limitations of large carnivores in protected areas are lacking. In the Northeast Tiger and Leopard National Park (NTLNP) in China, our camera trap survey in 2019 found 26–27 adult Amur tigers and 49–59 adult Amur leopards occurring in the park. Based on spatial area, current prey populations, and environmental carrying capacity of prey, we estimated the supportable number of tigers to be 55, 90, and 101 individuals, respectively. For leopard, these values were 95, 356, and 572, respectively. Further simulations indicated that human land use change scenarios did not contribute much to increasing the potential prey‐supportable populations of Amur tiger and leopard. Our results showed that the number of tigers and leopards in NTLNP is currently low and has a high recovery potential. However, even the highest supportable population is not enough to support the sustainable existence of an Amur tiger population. Therefore, we suggest that, in addition to further restoration and improvement of the prey population and habitat quality in NTLNP, managers should strengthen the connectivity between NTLNP and other habitat patches to form a well‐connected network of protected areas. Promoting the spread of tigers and leopards outwards from this source population in NTLNP through ecological corridor construction would enlarge the area of habitat and is a crucial measure for realizing the sustainable survival of an Amur tiger population in Northeast China.

Conservation potentials and limitations of large carnivores in protected areas: A case study in Northeast China

Mapping the habitat for the moose population in Northeast China by combining remote sensing products and random forests

Global warming is deeply influencing various ecological processes, especially regarding the phenological synchronization pattern between species, but more cases around the world are needed to reveal it. We report how the forest leaf phenology and ungulate molting respond differently to climate change, and investigate whether it will result in a potential phenology mismatch. Here, we explored how climate change might alter phenological synchronization between forest leaf phenology and Siberian roe deer (Capreolus pygargus) molting in northeast China based on a camera-trapping dataset of seven consecutive years, analyzing forest leaf phenology in combination with records of Siberian roe deer molting over the same period by means of wavelet analysis. We found that the start of the growing season of forest leaf phenology was advanced, while the end of the growing season was delayed, so that the length of the growing season was prolonged. Meanwhile, the start and the end of the molting of Siberian roe deer were both advanced in spring, but in autumn, the start of molting was delayed while the end of molting was advanced. The results of wavelet analysis also suggested the time lag of synchronization fluctuated slightly from year to year between forest leaf phenology and Siberian roe deer molting, with a potential phenology mismatch in spring, indicating the effect of global warming on SRD to forest leaf phenology. Overall, our study provides new insight into the synchronization between forest leaf phenology and ungulate molting, and demonstrates feasible approaches to data collection and analysis using camera-trapping data to explore global warming issues.

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Zexu Long

Papers

Study on Ecological Risk of Land Use in Urbanization Watershed Based on RS and GIS:A Case Study of Songhua River Watershed in Harbin Section

Identifying core habitats and corridors for giant pandas by combining multiscale random forest and connectivity analysis

Conservation potentials and limitations of large carnivores in protected areas: A case study in Northeast China

Mapping the habitat for the moose population in Northeast China by combining remote sensing products and random forests

Wavelet Analysis Reveals Phenology Mismatch between Leaf Phenology of Temperate Forest Plants and the Siberian Roe Deer Molting under Global Warming