Rongjie Yang

Dr. Rongjie Yang


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 June 2023 in Water
Verified
Journal Article
Open access
PDF file
RYRongjie Yang
Rongjie Yang
YCYingying Chen
Yingying Chen
YQYuling Qiu
Yuling Qiu
KLKezhu Lu
Kezhu Lu
XWXurui Wang
Xurui Wang
SLShiliang Liu
Shiliang Liu
Wetlands are often referred to as the Earth’s kidneys. However, wetlands worldwide are still negatively affected due to a lack of comprehensive understanding of wetland landscape ecological health (WLEH). Based on this background, we analyzed and compared the conceptual definitions, research progress, contents (in terms of structural, functional, and process health), and methods (indicator species approach, ecological integrity assessment, conceptual model evaluation including the vigor–organization–resilience (VOR), pressure–state–response (PSR), and ecological feature–function–socioeconomic (EFFS) models, and water–gas CO2 calculation) over the past 20 years (2000–2022). Moreover, the concept definition and research progress of ecosystem health (EH) and landscape ecological health (LEH) and WLEH research outlook were analyzed. In this study, it was shown that WLEH could be considered a LEH subset, while the LEH is a specific EH perspective. These three concepts share a common focus on ecosystem conditions, functions, and services while considering ecological processes and habitat characteristics. However, they differ in the scope and specific types of ecosystems considered. This review may provide references for ecological conservation and restoration of artificial and restored wetland landscapes.

6 June 2024 in Land
Verified
Journal Article
Open access
PDF file
SLShiliang Liu
Shiliang Liu
YCYingying Chen
Yingying Chen
RYRongjie Yang
Rongjie Yang
DLDi Li
Di Li
YQYuling Qiu
Yuling Qiu
QCQibing Chen
Qibing Chen
The degradation of urban ecology, particularly in metropolitan areas distinguished by dense populations and impervious surfaces, presents a worldwide challenge linked to swift urban expansion. Despite extensive documentation of urbanization’s impact on broad regions or specific urban ecosystems over defined time periods, there remains a scarcity of studies investigating the spatiotemporal dynamics of landscape pattern (LP) changes in specific ecosystems at small-to-medium scales within inland megacities as a response to urbanization. Therefore, this work focused on the Bailuwan Wetland Park (BWP) in Chengdu, an inland megacity in southwestern China. Employing satellite imagery data from selected years spanning the previous decade (2010–2021, encompassing 2010, 2012, 2015, 2018, and 2021), this investigation delved into the influences of urbanization on the LP over various time-frames and across different land use/land cover (LULC) types. Our study revealed that urbanization has a significant impact on the patch-/landscape-level characteristics, including the class area (CA), number of patches (NP), patch density (PD), percentage of landscape (PLAND), aggregation index (AI), contagion index (CONTAG), largest patch index (LPI), landscape shape index (LSI), fractal dimension index (FRAC_MN), Shannon’s diversity (SHDI), and evenness index (SHEI). Over the period from 2010 to 2021, NP and PD experienced notable increases, while landscape shape (LSI/FRAC_MN) exhibited greater complexity and fragmentation (PLAND) intensified. Further, landscape heterogeneity (AI/CONTAG) and diversity (SHDI/SHEI) decreased. Particularly significant was the conversion of 52 ha of agricultural land to vegetation, resulting in heightened complexity and fragmentation in vegetation patterns. Additionally, the CA of lakes and rivers decreased following the establishment of the park, while the CA and NP of bare land presented significant increases. These findings suggest that rapid urbanization significantly influences the spatial–temporal dynamics of wetland landscape patterns. Consequently, it is imperative for society to prioritize the restoration and protection of urban constructed wetlands.

25 September 2023 in Water
Verified
Journal Article
Open access
PDF file
RYRongjie Yang
Rongjie Yang
YCYingying Chen
Yingying Chen
DLdi li
di li
YQYuling Qiu
Yuling Qiu
KLKezhu Lu
Kezhu Lu
HSHuixing Song
Huixing Song
Inland lake water–air interfaces, particularly the partial pressure of CO2 (pCO2), have become key parameters in the study of global carbon cycle changes. However, there are few studies on short-term daily variations in pCO2 in urbanizing lakes. The fluctuations in pCO2 and CO2 fluxes (fCO2) were monitored biweekly on-site for pCO2 assessments during daytime hours (7:00–17:00 CST) from January to September 2020 in an urbanizing lake located in Southwest China. We found a pronounced and uninterrupted decline in the average levels of pCO2 and fCO2 from 7:00 to 17:00 CST. Notably, the mornings (7:00–12:00 CST) exhibited substantially elevated pCO2 and fCO2 values compared to the afternoons. Specifically, compared to 7:00, the mean pCO2 and fCO2 at 17:00 CST decreased by ca. 74% and 112%, respectively. The average daytime pCO2 was 707 ± 642 μatm, significantly higher than the typical atmospheric CO2 levels of 380–420 μatm, while the average pCO2 on 9 January, 1 April, and 27 July was lower than typical atmospheric CO2. Each month, all water environmental parameters showed significant differences. pCO2 and fCO2 reached maximums in September; water temperature and turbidity significantly increased; and pH, dissolved oxygen and transparency markedly decreased. Additionally, the correlation between pCO2 and environmental factors demonstrated that the nutrient levels, dissolved oxygen, pH, and transparency/turbidity had significant roles in CO2 dynamics in this lake. Therefore, this urbanizing lake could serve as a CO2 source and sink during the daytime.

2 July 2024 in Science of The Total Environment
Verified
Journal Article
Open access
RYRongjie Yang
Rongjie Yang
HSHuixing Song
Huixing Song
QQQiao Qin
Qiao Qin
YCYingying Chen
Yingying Chen
DLDi Li
Di Li
SLShiliang Liu
Shiliang Liu
Globally, numerous freshwater lakes exist, and rapid urbanization has impacted carbon biogeochemical cycling at the interface where water meets air in these bodies. However, there is still a limited understanding of CO2 absorption/emission in eutrophic urbanizing lakes. This study therefore involved biweekly in-situ monitoring to evaluate fluctuations in the partial pressure (pCO2) and flux (fCO2) of CO2 and associated parameters from January to September 2020 (7:00-17:00 CST) in an urbanizing lake in southwestern China. Our study revealed that during the daylight hours of the 11 sampling days, both pCO2 and fCO2 consistently demonstrated decreasing trends from the early morning period to the late afternoon period, with notable increases on May 7th and August 15th, respectively. Interestingly, unlike our previous findings, an nonsignificant difference (p > 0.05) in mean pCO2 and fCO2 was observed between the morning period and the afternoon period (n = 22). Furthermore, the mean pCO2 in January (~105 μatm; n = 4) and April (133-212 μatm; n = 8) was below the typical atmospheric CO2 level (C-sink), while that in the other months surpassed 410 μatm (C-source), although the average values (n = 44) of pCO2 and fCO2 were 960 ± 841 μatm and 57 ± 85 mmol m-2 h-1, respectively. Moreover, the pCO2 concentration was significantly greater in summer (May to August, locally reaching 1087 μatm) than in spring (January to April at 112 μatm), indicating a seasonal shift between the C-sink (spring) and the C-source (summer). In addition, a significant positive correlation in pCO2/fCO2 with chlorophyll-a/nitrate but a negative correlation in dissolved oxygen and total phosphorus were recorded, suggesting that photosynthesis and respiration were identified as the main drivers of CO2 absorption/emissions, while changes in nitrate and phosphorus may be attributed to urbanization. Overall, our investigations indicated that this lightly eutrophic lake demonstrated a distinct shifting pattern of CO2 source-sink variability at daily and seasonal scales.