Urbanisation process generates more independently-acting stressors and ecosystem functioning impairment in tropical Andean streams

The impact of urbanisation on green total factor productivity: Exploring threshold and mediating effects of human capital

Green development is main direction of high-quality economic development in China. Urbanisation and human capital (HC) are important factors affecting green development. This study examines effects of urbanisation and HC on green total factor productivity (GTFP) using least squares dummy variable model, based on provincial data in China from 2001 to 2019. This study then explored impact of urbanisation on GTFP through HC (educated HC, healthy HC, and HC structure), adopting mediating effect and threshold effect model. The results showed that urbanisation and three types of HC promote GTFP in China and coastal region. In inland region, urbanisation has insignificant impact on GTFP, while educated HC and HC structure improve it. The mediating analysis revealed that educated and healthy HC in China and coastal region enhance promotion effect of urbanisation on GTFP, whereas HC structure hinders it. In inland region, only healthy HC stimulates promotion effect of urbanisation on GTFP. Considering threshold effect of educated and healthy HC, promotion effect of urbanisation on GTFP is weaker than threshold value; but effect is stronger above threshold value. The promotion effect of urbanisation on GTFP is stronger when value of HC structure is below the threshold, while effect is weakened as value exceeds threshold value. Policy implications are documented to promote urbanisation in a differentiated manner, increase investment in HC, and strengthen coordination between urbanisation and HC.

Assessing production-living-ecological spaces and its urban-rural gradients in Xiangyang City, China: insights from land-use function symbiosis

Understanding the formation process and pattern of production-living-ecological spaces (PLES) is crucial for sustainable land-use management and adaptive city governance. However, previous studies have neglected the symbiotic relationships between land-use functions (LUFs) in identifying and optimizing PLES. To address this gap, this paper proposes a technical framework for assessing PLES from a LUF symbiosis perspective. A case study was conducted in Xiangyang City, China, to identify PLES and analyze its urban-rural differentiation using the symbiosis degree model and landscape pattern indices. Our findings revealed that the symbiotic relationships between LUFs varied. There were 25 combination types of PLES in Xiangyang City, with significantly varied area proportions and spatial distribution. The landscape types and fragmentation of PLES increased along with the gradient change from the old urban area to the rural area. Furthermore, we proposed a PLES optimization strategy involving LUFs symbiosis and the urban-rural gradient. Our study enriches the dimensions of PLES assessment and supports better-coordinated planning and the protection of PLES.

Analysis on the synchronized development between urbanization process and eco-efficiency through the sustainability lens

Urbanization and eco-efficiency are two interactive systems, contributing to sustainable urban development jointly. However, the synchronized development between them has not received sufficient attention. In light of this gap, this paper conducts an analysis on seeking the synchronized development between sustainable urbanization and eco-efficiency in the context of China. The aim of this study is to uncover the spatial and temporal performance of the synchronized relationship between urbanization process (UP) and eco-efficiency (EE) in a sample of 255 Chinese cities. To this end, entropy method, super efficiency SBM and coupling coordination degree model are employed to conduct the research analysis, covering the period of 2005 to 2019. The findings of this study reveal that (1) there is about 97% of the surveyed cities that exhibit a moderate level of coupling coordination between urbanization process and eco-efficiency (CC-UE). (2) Spatial disparities in the performance of CC-UE are evident, with cities in South and Southeast China demonstrating better CC-UE performance than their counterparts. However, this disparity has been gradually diminishing in recent years. (3) Local perspective presented an evident spatial autocorrelation within the 255 cities analyzed. These research findings provide valuable insights not only for the policy-makers and practitioners to adopt measures for achieving a synchronized development between urbanization process and eco-efficiency in the Chinese context, but also for further studies on sustainable development in the international context.

Groundwater Amphipods of the Hyporheic Interstitial: A Case Study from Luxembourg and The Greater Region

Hyporheic interstitials are ecologically dynamic and often neglected aquatic environments. In this study, groundwater amphipods (Niphargidae, Pseudoniphargidae and Crangonyctidae) were sampled in hyporheic interstitials throughout Luxembourg and The Greater Region and specimens were analyzed by DNA barcoding. Sites characterized by gravel or coarse sand and high flow velocities of incoming water were the most species- and specimen-rich. A total of 11 species were detected, of which the Niphargus aquilex lineage EF of the N. aquilex cryptic species complex and juveniles of N. schellenbergi dominated the data set, but an unknown lineage of the N. aquilex-complex was also found. Some regions appeared to be devoid of groundwater amphipods. We hypothesize that underlying sandstone formations resulting in low sediment porosity may prevent physical colonization, but also that historical water pollution may have a long-lasting effect, either through the persistence of contaminants in the sediment or low recolonization rates of affected populations. In summary, our approach expanded regional species inventories, confirmed known occurrences, and validated previously questionable or historical morphology-based detections. In addition, the collection of absence data provided valuable insights into local extinctions. Finally, DNA-based distribution data are needed to gather information on the ecological affinities of groundwater amphipods to understudied hyporheic interstitial environments.

The Good, the Bad, and the Ugly of Urbanization: Response of a Bird Community in the Neotropical Andes

Urbanization constitutes one of the most aggressive drivers of habitat and biodiversity loss worldwide. However, studies focused on determining the response of local biodiversity to urbanization are still scarce, especially in tropical ecosystems. Urban ecosystems are characterized by low biological productivity which in turn leads to a reduction in biodiversity. However, the responses to urbanization should be species dependent. For instance, changes in the availability of resources can favor certain species with specific characteristics. We assessed the effects of the urbanization process on a bird community in a city located in the Tropical Andes of southern Ecuador, a region widely recognized for its diversity and endemism of birds. We selected three independent localities in each of the four levels of the urbanization gradient in the study area (forest, forest-pasture, pasture, and urban). In each locality, we sampled the bird community by visual and auditory surveys along 1 km transects between 2016 and 2017. We recorded a total of 1,257 individuals belonging to 74 bird species. We evaluated if the responses of richness and abundance of birds are dependent on trophic guild and foraging strata. We found a significant decrease in bird species richness and abundance from forest to urban sites. However, the response of birds was dependent on the trophic guild and foraging strata. Granivorous birds showed a positive response associated with the urbanization gradient while insectivorous birds showed a negative response. Insectivorous birds were more abundant in forest sites and decreased in abundance across the urbanization gradient. We found that the proportion of birds using different foraging strata drastically changed along urban gradient. Forest sites exhibited a bird community using a variety of habitats, but the bird community became simpler toward the most urbanized sites. Our findings showed different effects of urbanization on bird communities. The ugly: urbanization leads to a dramatic reduction in the diversity of birds, which is consistent in cities with different characteristics and ecological contexts. On the other hand, the responses of bird guilds to urbanization are species dependent. Some guilds are positively impacted by urbanization and show increases in species richness and abundance while other guilds are negatively impacted.