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In the last 15 years, the west population of white-naped crane (Antigone vipio) decreased dramatically despite the enhanced conservation actions in both breeding and wintering areas. Recent studies highlighted the importance of protecting the integrity of movement connectivity for migratory birds. Widespread and rapid landcover changes may exceed the adaptive capacity of migrants, leading to the collapse of migratory networks. In this study, using satellite tracking data, we modeled and characterized the migration routes of the white-naped crane at three spatial levels (core area, migratory corridor, and migratory path) based on the utilization distribution for two eras (1990s and 2010s) spanning 20 years. Our analysis demonstrated that the white-naped crane shifted its migratory route, which is supported by other lines of evidences. The widespread loss of wetlands, especially within the stopover sites, might have caused this behavioral adaptation. Moreover, our analysis indicated that the long-term sustainability of the new route is untested and likely to be questionable. Therefore, directing conservation effects to the new route might be insufficient for the long-term wellbeing of this threatened crane and large-scale wetland restorations in Bohai Bay, a critical stopover site in the East Asian-Australasian flyway, are of the utmost importance to the conservation of this species.
Yifei Jia; Yunzhu Liu; Shengwu Jiao; Jia Guo; Cai Lu; Yan Zhou; Yuyu Wang; Guangchun Lei; Li Wen; Xunqiang Mo. Shifting of the Migration Route of White-Naped Crane (Antigone vipio) Due to Wetland Loss in China. Remote Sensing 2021, 13, 2984 .
AMA StyleYifei Jia, Yunzhu Liu, Shengwu Jiao, Jia Guo, Cai Lu, Yan Zhou, Yuyu Wang, Guangchun Lei, Li Wen, Xunqiang Mo. Shifting of the Migration Route of White-Naped Crane (Antigone vipio) Due to Wetland Loss in China. Remote Sensing. 2021; 13 (15):2984.
Chicago/Turabian StyleYifei Jia; Yunzhu Liu; Shengwu Jiao; Jia Guo; Cai Lu; Yan Zhou; Yuyu Wang; Guangchun Lei; Li Wen; Xunqiang Mo. 2021. "Shifting of the Migration Route of White-Naped Crane (Antigone vipio) Due to Wetland Loss in China." Remote Sensing 13, no. 15: 2984.
Aim Exotic species invasion often leads to declines in local and regional biodiversity, particularly in freshwater ecosystems. This biodiversity loss is generally facilitated by human activities such as land cover change and hydrological alternation. Recent advances in stable isotope analysis (SIA) have been highlighted in many studies addressing fundamental issues in invasion ecology, especially in quantifying competition for resources between native and exotic species. However, how anthropogenic disturbance influences trophic relationships among invasive and native species remains poorly understood. Location Middle-lower Yangtze River Region, China. Methods To investigate the effects of human disturbance on interspecific trophic interactions, this study compared isotopic niche space and overlap of the introduced red swamp crayfish (Procambarus clarkii) and the native oriental river shrimp (Macrobrachium nipponense) and freshwater snail (Bellamya aeruginosa) in natural and modified wetlands. Results Based on carbon and nitrogen SIA, we found ubiquitous niche shifts in macroinvertebrates with increased competition, which might lead to significant niche contraction in modified habitats at both community and population scales. Moreover, the isotopic niche width of the exotic crayfish was twice as larger as that of natives at both habitats, suggesting that the exotic P. clarkii had great competitive superiority over the native species. However, the effects of habitat modification on niche overlap were inconsistent. While the niche overlap between crayfish and shrimp was significantly higher in modified habitats than in natural open waters, niche overlap between crayfish and the snail was significantly reduced. Main conclusions Collectively, our findings highlight that the competitive outcomes of interspecific trophic interactions can be dependent on the prey availability and diversity, which embraces both the classic optimal foraging theory and competition theory to understand how environmental change, such as habitat alternation, affects the biological invasion processes.
Yuyu Wang; Wenzhuo Tan; Bin Li; Li Wen; Guangchun Lei. Habitat alteration facilitates the dominance of invasive species through disrupting niche partitioning in floodplain wetlands. Diversity and Distributions 2021, 27, 1861 -1871.
AMA StyleYuyu Wang, Wenzhuo Tan, Bin Li, Li Wen, Guangchun Lei. Habitat alteration facilitates the dominance of invasive species through disrupting niche partitioning in floodplain wetlands. Diversity and Distributions. 2021; 27 (9):1861-1871.
Chicago/Turabian StyleYuyu Wang; Wenzhuo Tan; Bin Li; Li Wen; Guangchun Lei. 2021. "Habitat alteration facilitates the dominance of invasive species through disrupting niche partitioning in floodplain wetlands." Diversity and Distributions 27, no. 9: 1861-1871.
Migratory waterbirds concentrated in freshwater ecosystems in mosaic environments rely on quality habitats for overwintering. At West Dongting Lake National Nature Reserve (WDLNNR), China, land-use change and hydrology alternation are compounding factors that have affected important wintering areas for migratory waterbirds. Presently, changes in the hydrology and landscape have reshaped natural wintering habitats and their availability, though the impact of hydrological management on habitat selection of wintering waterbirds is largely unknown. In this study, we classified differentially managed habitats and calculated their area using the normalized difference vegetation index (NDVI) to evaluate suitable habitat availability over the study period (2016–2017 and 2017–2018 wintering periods). We then used social behavioral association network (SBAN) model to compare habitat quality through species-species social interactions and species-habitat associations in lakes with different hydrological management. The results indicated that social interactions between and within species structured wintering waterbirds communities, which could be dominated by one or more species, while dominant species control the activities of other co-existing species. Analysis of variance (ANOVA) tests indicated significant differences in SBAN metrics between lakes (p = 0.0237) and habitat (p< 0.0001) levels. Specifically, lakes with managed hydrology were preferred by more species. The managed lakes had better habitat quality in terms of significantly higher habitat areas (p< 0.0001) and lower habitat transitions (p = 0.0113). Collectively, our findings suggest that proper hydrological management can provide continuous availability of quality habitats, especially mudflats and shallow waters, for a stable SBAN to ensure a wintering waterbirds community with more sympatric species in a dynamic environment.
Muhammad Rasool; Muhammad Hassan; Xiaobo Zhang; Qing Zeng; Yifei Jia; Li Wen; Guangchun Lei. Habitat Quality and Social Behavioral Association Network in a Wintering Waterbirds Community. Sustainability 2021, 13, 6044 .
AMA StyleMuhammad Rasool, Muhammad Hassan, Xiaobo Zhang, Qing Zeng, Yifei Jia, Li Wen, Guangchun Lei. Habitat Quality and Social Behavioral Association Network in a Wintering Waterbirds Community. Sustainability. 2021; 13 (11):6044.
Chicago/Turabian StyleMuhammad Rasool; Muhammad Hassan; Xiaobo Zhang; Qing Zeng; Yifei Jia; Li Wen; Guangchun Lei. 2021. "Habitat Quality and Social Behavioral Association Network in a Wintering Waterbirds Community." Sustainability 13, no. 11: 6044.
Habitat degradation is expected to alter community structure and consequently, ecosystem functions including the maintenance of biodiversity. Understanding the underlying abiotic and biotic assembly mechanisms controlling temporal and spatial community structure and patterns is a central issue in biodiversity conservation. In this study, using monthly time series of fish abundance data collected over a three-year period, we compared the temporal community dynamics in natural habitats and poplar plantations in one of the largest river-lake floodplain ecosystems in China, the Dongting Lake. We found a prevailing strong positive species covariance, i.e. species abundance changes in the same way, in all communities that was significantly negatively impacted by higher water nutrient levels. In contrast to species covariance, community stability, which was measured by the average of aggregated abundance divided by temporal standard deviation, was significantly higher in poplar plantations than in natural habitats. The positive species covariance, which was consistent for both wet and dry years and among habitat types, had significantly negative effects on community stability. Furthermore, our results demonstrated that the ecological stochasticity (i.e. community assembly processes generating diversity patterns that are indistinguishable from random chance) was significantly higher in natural sites than in poplar plantations, suggesting that deterministic processes might control the community composition (richness and abundance) at the modified habitat through reducing species synchrony and positive species covariance observed in the natural habitats, leading to significantly lower temporal β-diversity. When combined, our results suggest that habitat modification created environmental conditions for the development of stable fish community in the highly dynamic floodplains, leading to niche-based community with lower temporal β-diversity.
Bin Li; Yuyu Wang; Wenzhuo Tan; Neil Saintilan; Guangchun Lei; Li Wen. Land cover alteration shifts ecological assembly processes in floodplain lakes: Consequences for fish community dynamics. Science of The Total Environment 2021, 782, 146724 .
AMA StyleBin Li, Yuyu Wang, Wenzhuo Tan, Neil Saintilan, Guangchun Lei, Li Wen. Land cover alteration shifts ecological assembly processes in floodplain lakes: Consequences for fish community dynamics. Science of The Total Environment. 2021; 782 ():146724.
Chicago/Turabian StyleBin Li; Yuyu Wang; Wenzhuo Tan; Neil Saintilan; Guangchun Lei; Li Wen. 2021. "Land cover alteration shifts ecological assembly processes in floodplain lakes: Consequences for fish community dynamics." Science of The Total Environment 782, no. : 146724.
The Lesser White‐fronted Goose (Anser erythropus), smallest of the “gray” geese, is listed as Vulnerable on the IUCN Red List and protected in all range states. There are three populations, with the least studied being the Eastern population, shared between Russia and China. The extreme remoteness of breeding enclaves makes them largely inaccessible to researchers. As a substitute for visitation, remotely tracking birds from wintering grounds allows exploration of their summer range. Over a period of three years, and using highly accurate GPS tracking devices, eleven individuals of A. erythropus were tracked from the key wintering site of China, to summering, and staging sites in northeastern Russia. Data obtained from that tracking, bolstered by ground survey and literature records, were used to model the summer distribution of A. erythropus. Although earlier literature describes a patchy summer range, the model suggests a contiguous summer habitat range is possible, although observations to date cannot confirm A. erythropus is present throughout the modeled range. The most suitable habitats are located along the coasts of the Laptev Sea, primarily the Lena Delta, in the Yana‐Kolyma Lowland, and smaller lowlands of Chukotka with narrow riparian extensions upstream along major rivers such as the Lena, Indigirka, and Kolyma. The probability of A. erythropus presence is related to areas with altitude less than 500 m with abundant wetlands, especially riparian habitat, and a climate with precipitation of the warmest quarter around 55 mm and mean temperature around 14°C during June‐August. Human disturbance also affects site suitability, with a gradual decrease in species presence starting around 160 km from human settlements. Remote tracking of animal species can bridge the knowledge gap required for robust estimation of species distribution patterns in remote areas. Better knowledge of species' distribution is important in understanding the large‐scale ecological consequences of rapid global change and establishing conservation management strategies.
Haitao Tian; Diana Solovyeva; Gleb Danilov; Sergey Vartanyan; Li Wen; Jialin Lei; Cai Lu; Peter Bridgewater; Guangchun Lei; Qing Zeng. Combining modern tracking data and historical records improves understanding of the summer habitats of the Eastern Lesser White‐fronted Goose Anser erythropus. Ecology and Evolution 2021, 11, 4126 -4139.
AMA StyleHaitao Tian, Diana Solovyeva, Gleb Danilov, Sergey Vartanyan, Li Wen, Jialin Lei, Cai Lu, Peter Bridgewater, Guangchun Lei, Qing Zeng. Combining modern tracking data and historical records improves understanding of the summer habitats of the Eastern Lesser White‐fronted Goose Anser erythropus. Ecology and Evolution. 2021; 11 (9):4126-4139.
Chicago/Turabian StyleHaitao Tian; Diana Solovyeva; Gleb Danilov; Sergey Vartanyan; Li Wen; Jialin Lei; Cai Lu; Peter Bridgewater; Guangchun Lei; Qing Zeng. 2021. "Combining modern tracking data and historical records improves understanding of the summer habitats of the Eastern Lesser White‐fronted Goose Anser erythropus." Ecology and Evolution 11, no. 9: 4126-4139.
Studying social‐behavior and species associations in ecological communities is challenging because it is difficult to observe the interactions in the field. Animal behavior is especially difficult to observe when selection of habitat and activities are linked to energy costs of long‐distance movement. Migrating communities tend to be resource specific and prefer environments that offer more suitability for coexisting in a shared space and time. Given the recent advances in digital technologies, digital video recording systems are gaining popularity in wildlife research and management. We used digital video recording cameras to study social interactions and species–habitat linkages for wintering waterbirds communities in shared habitats. Examining over 8,640 hr of video footages, we built tetrapartite social‐behavioral association network of wintering waterbirds over habitat (n = 5) selection events in sites with distinct management regimes. We analyzed these networks to identify hub species and species role in activity persistence, and to explore the effects of hydrological regime on these network characteristics. Although the differences in network attributes were not significant at treatment level (p = .297) in terms of network composition and keystone species composition, our results indicated that network attributes were significantly different (p = .000, r2 = .278) at habitat level. There were evidences suggesting that the habitat quality was better at the managed sites, where the formed networks had more species, more network nodes and edges, higher edge density, and stronger intra‐ and inter‐species interactions. In addition, we also calculated the species interaction preference scores (SIPS) and behavioral interaction preference scores (BIPS) of each network. The results showed that species synchronize activities in shared space for temporal niche partitioning in order to avoid or minimize any potential competition for shared space. Our social network analysis (SNA) approach is likely to provide a practical use for ecosystem management and biodiversity conservation.
Muhammad Awais Rasool; Xiaobo Zhang; Muhammad Azher Hassan; Tanveer Hussain; Cai Lu; Qing Zeng; Boyong Peng; Li Wen; Guangchun Lei. Construct social‐behavioral association network to study management impact on waterbirds community ecology using digital video recording cameras. Ecology and Evolution 2021, 11, 2321 -2335.
AMA StyleMuhammad Awais Rasool, Xiaobo Zhang, Muhammad Azher Hassan, Tanveer Hussain, Cai Lu, Qing Zeng, Boyong Peng, Li Wen, Guangchun Lei. Construct social‐behavioral association network to study management impact on waterbirds community ecology using digital video recording cameras. Ecology and Evolution. 2021; 11 (5):2321-2335.
Chicago/Turabian StyleMuhammad Awais Rasool; Xiaobo Zhang; Muhammad Azher Hassan; Tanveer Hussain; Cai Lu; Qing Zeng; Boyong Peng; Li Wen; Guangchun Lei. 2021. "Construct social‐behavioral association network to study management impact on waterbirds community ecology using digital video recording cameras." Ecology and Evolution 11, no. 5: 2321-2335.
Anthropogenic disturbance to natural hydrological connectivity, both longitudinal, lateral, and vertical, is threatening the ecological integrity of the freshwater realm. River-floodplain system is particularly adversely affected by the reduction in lateral hydrological connectivity (LHC), representing one of major biodiversity hotspots under increasingly pressure. Many studies have demonstrated that LHC has great influence on the spatial variations of flora and fauna communities (i.e. spatial β diversity) through facilitating dispersal. However, to fully understand the impact of anthropogenic disturbances on biodiversity, we must also understand how ecological communities change over time (i.e. temporal β diversity, TBI) and the underlying processes. To evaluate the processes structuring ecological communities, we examined the macroinvertebrate TBI in habitats along the gradient of LHC for an entire hydrological cycle in West Dongting Lake, a Ramsar-listed floodplain wetland at the middle reach of Yangtze River. Our results showed that the total spatial β diversity fluctuated with water level and peaked at high-water phase, and LHC was the driving forcing affecting both species richness and abundance in all hydrological periods. In particular, species richness and abundance were highest in habitats with medium LHC levels for water-rising and high-water periods reflecting the intermediate disturbance hypothesis except for water-recessing, during which there was no clear pattern. While replacement determined β diversity in most sites at water-rising and high-water phases, the contribution of nestedness were high during water-withdrawing phase. From water-rising to high-water, macroinvertebrates from other habitats spread to the modified mudflats, which had the lowest LHC, along with the floods. During water-withdrawing period, β diversity and its turnover component of all habitats were low compared with other hydrological phases. Temporal β diversity analysis illustrated that the species dispersal was the main mechanism underlying the temporal and spatial variations in the observed community patterns. These findings demonstrated that hydrological connectivity was critical to maintaining the ecological integrity of river-floodplain ecosystems.
Rui Dong; Yuyu Wang; Cai Lu; Guangchun Lei; Li Wen. The seasonality of macroinvertebrate β diversity along the gradient of hydrological connectivity in a dynamic river-floodplain system. Ecological Indicators 2020, 121, 107112 .
AMA StyleRui Dong, Yuyu Wang, Cai Lu, Guangchun Lei, Li Wen. The seasonality of macroinvertebrate β diversity along the gradient of hydrological connectivity in a dynamic river-floodplain system. Ecological Indicators. 2020; 121 ():107112.
Chicago/Turabian StyleRui Dong; Yuyu Wang; Cai Lu; Guangchun Lei; Li Wen. 2020. "The seasonality of macroinvertebrate β diversity along the gradient of hydrological connectivity in a dynamic river-floodplain system." Ecological Indicators 121, no. : 107112.
• The decline of submerged macrophytes in shallow lakes and wetlands has cascade effects on regional and global biodiversity. In the last two decades, the rapid disappear of macrophyte beds in the floodplain lakes of the middle lower Yangtze River has become a great concern for the ecological security of the region. • This study aims to quantify the effects of water depth on biomass production and clonal (i.e. stolons and winter buds) and sexual reproduction (i.e. fruits) of Vallisneria natans, a cosmopolitan, perennial submergent species. • Results of the research clearly demonstrated the unimodal relationship between biomass production and water depth, and there was an optimal range of 35–50 cm, beyond which total biomass decreased. Also, both clonal and sexual reproductive outputs decreased with water depth. Furthermore, for the first time, the study revealed the distinct reproduction patterns of the individuals originated from seeds and clonal propagules. While seed-generated plants produced significantly more fruits (and no winter buds), plants developed from clonal propagules produced more stolons and winter buds. • There findings plead further researches on V. natans seedling establishment and reproductive ecology because of the importance of winter buds as food for wintering waterbirds in the middle Yangtze floodplains.
Xiaobo Zhang; Kaidi Guo; Cai Lu; Rasool Muhammad Awais; Yifei Jia; Liqin Zhong; Peizhong Liu; Rui Dong; Dan Liu; Weikun Zeng; Guangchun Lei; Li Wen. Effects of origin and water depth on morphology and reproductive modes of the submerged plant Vallisneria natans. Global Ecology and Conservation 2020, 24, e01330 .
AMA StyleXiaobo Zhang, Kaidi Guo, Cai Lu, Rasool Muhammad Awais, Yifei Jia, Liqin Zhong, Peizhong Liu, Rui Dong, Dan Liu, Weikun Zeng, Guangchun Lei, Li Wen. Effects of origin and water depth on morphology and reproductive modes of the submerged plant Vallisneria natans. Global Ecology and Conservation. 2020; 24 ():e01330.
Chicago/Turabian StyleXiaobo Zhang; Kaidi Guo; Cai Lu; Rasool Muhammad Awais; Yifei Jia; Liqin Zhong; Peizhong Liu; Rui Dong; Dan Liu; Weikun Zeng; Guangchun Lei; Li Wen. 2020. "Effects of origin and water depth on morphology and reproductive modes of the submerged plant Vallisneria natans." Global Ecology and Conservation 24, no. : e01330.
Geographical gradients in species diversity have long fascinated biogeographers and ecologists. However, the extent and generality of the effects of the important factors governing functional diversity (FD) patterns are still debated, especially for the freshwater domain. We examined the relationship between lake productivity and functional diversity of waterbirds sampled from 35 lakes and reservoirs in northern China with a geographic coverage of over 5 million km2. We used structural equation modeling (SEM) to explore the causal relationships between geographic position, climate, lake productivity, and waterbird FD. We found unambiguous altitudinal and longitudinal gradients in lake productivity and waterbird FD, which were strongly mediated by local environmental factors. Specifically, we found (a) lake productivity increased northeast and decreased with altitude. The observed geographic and altitudinal gradients were driven by climatic conditions and nutrient availability, which collectively explained 93% of the variations in lake productivity; (b) waterbird FD showed similar geographic and altitudinal gradients; the environmental factors which had direct and/or indirect effects on these gradients included climate and lake area, which collectively explained more than 39% of the variation in waterbird FD; and 3) a significant (p = .029) causality between lake productivity and waterbird FD was confirmed. Nevertheless, the causality link was relatively weak in comparison with climate and lake area (the standardized path coefficient was 0.55, 0.23, and 0.03 for climate, lake area, and productivity, respectively). Our study demonstrates how the application of multivariate technique (e.g., SEM) enables the illustration of complex causal paths in ecosystems, enhancing mechanistic explanations that underlie the observed broadscale biodiversity gradients.
Yamian Zhang; Wenzhuo Tan; Qing Zeng; Haitao Tian; Yifei Jia; Guangchun Lei; Li Wen. Lake productivity and waterbird functional diversity across geographic and environmental gradients in temperate China. Ecology and Evolution 2020, 10, 11237 -11250.
AMA StyleYamian Zhang, Wenzhuo Tan, Qing Zeng, Haitao Tian, Yifei Jia, Guangchun Lei, Li Wen. Lake productivity and waterbird functional diversity across geographic and environmental gradients in temperate China. Ecology and Evolution. 2020; 10 (20):11237-11250.
Chicago/Turabian StyleYamian Zhang; Wenzhuo Tan; Qing Zeng; Haitao Tian; Yifei Jia; Guangchun Lei; Li Wen. 2020. "Lake productivity and waterbird functional diversity across geographic and environmental gradients in temperate China." Ecology and Evolution 10, no. 20: 11237-11250.
Large river floodplain systems (LRFS) are among the most diverse and dynamic ecosystems. Accurately monitoring the dynamics of LRFS over long time series is fundamental and essential for their sustainable development. However, challenges remain because the spatial distribution of LRFS is never static due to inter- and intra-annual changes in environmental conditions. In this study, we developed and tested a methodological framework to re-construct the long-term wetland dynamics in Dongting Lake, China, utilizing an unsupervised machine-learning algorithm (UMLA) on the basis of MODIS (Moderate Resolution Imaging Spectroradiometer) EVI (Enhanced Vegetation Index) time series. Our results showed that the UMLA achieved comparable performance to the time-consuming satellite image segmentation method with a Kappa coefficient of agreement greater than 0.75 and an overall accuracy over 85%. With the re-constructed annual wetland distribution maps, we found that 31.35% of wet meadows, one of most important ecological assets in the region, disappeared at an average rate of c.a. 1660 ha year−1 during the past two decades, which suggests that the Dongting Lake is losing its ecological function of providing wintering ground for migratory water birds, and remediation management actions are urgently required. We concluded that UMLA offers a fast and cost-efficient alternative to monitor ecological responses in a rapidly changing environment.
Lei Jing; Yan Zhou; Qing Zeng; Shuguang Liu; Guangchun Lei; Cai Lu; Li Wen. Exploring Wetland Dynamics in Large River Floodplain Systems with Unsupervised Machine Learning: A Case Study of the Dongting Lake, China. Remote Sensing 2020, 12, 2995 .
AMA StyleLei Jing, Yan Zhou, Qing Zeng, Shuguang Liu, Guangchun Lei, Cai Lu, Li Wen. Exploring Wetland Dynamics in Large River Floodplain Systems with Unsupervised Machine Learning: A Case Study of the Dongting Lake, China. Remote Sensing. 2020; 12 (18):2995.
Chicago/Turabian StyleLei Jing; Yan Zhou; Qing Zeng; Shuguang Liu; Guangchun Lei; Cai Lu; Li Wen. 2020. "Exploring Wetland Dynamics in Large River Floodplain Systems with Unsupervised Machine Learning: A Case Study of the Dongting Lake, China." Remote Sensing 12, no. 18: 2995.
Coastal wetlands are a critical component of the coastal landscape that are increasingly threatened by sea level rise and other human disturbance. Periodically mapping wetland distribution is crucial to coastal ecosystem management. Ensemble algorithms (EL), such as random forest (RF) and gradient boosting machine (GBM) algorithms, are now commonly applied in the field of remote sensing. However, the performance and potential of other EL methods, such as extreme gradient boosting (XGBoost) and bagged trees, are rarely compared and tested for coastal wetland mapping. In this study, we applied the three most widely used EL techniques (i.e., bagging, boosting and stacking) to map wetland distribution in a highly modified coastal catchment, the Manning River Estuary, Australia. Our results demonstrated the advantages of using ensemble classifiers to accurately map wetland types in a coastal landscape. Enhanced bagging decision trees, i.e., classifiers with additional methods to increasing ensemble diversity such as RF and weighted subspace random forest, had comparably high predictive power. For the stacking method evaluated in this study, our results are inconclusive, and further comprehensive quantitative study is encouraged. Our findings also suggested that the ensemble methods were less effective at discriminating minority classes in comparison with more common classes. Finally, the variable importance results indicated that hydro-geomorphic factors, such as tidal depth and distance to water edge, were among the most influential variables across the top classifiers. However, vegetation indices derived from longer time series of remote sensing data that arrest the full features of land phenology are likely to improve wetland type separation in coastal areas.
Li Wen; Michael Hughes. Coastal Wetland Mapping Using Ensemble Learning Algorithms: A Comparative Study of Bagging, Boosting and Stacking Techniques. Remote Sensing 2020, 12, 1683 .
AMA StyleLi Wen, Michael Hughes. Coastal Wetland Mapping Using Ensemble Learning Algorithms: A Comparative Study of Bagging, Boosting and Stacking Techniques. Remote Sensing. 2020; 12 (10):1683.
Chicago/Turabian StyleLi Wen; Michael Hughes. 2020. "Coastal Wetland Mapping Using Ensemble Learning Algorithms: A Comparative Study of Bagging, Boosting and Stacking Techniques." Remote Sensing 12, no. 10: 1683.
Better understanding of the mechanisms structuring ecological communities is not only a long-term theoretical pursuit in ecology but also critical for biodiversity conservation. Here, we used two complementary approaches (β-diversity partitioning, and phylogenetic and functional null models) to explore the processes structuring wintering waterbird communities in the floodplain lakes of middle-lower Yangtze River (MLYR), China. We found that 1) neutral assembly might be the predominant process shaping the composition of wintering waterbird communities in MLYR; 2) compared to environmental factors, spatial variables, in particular those describing the large scale spatial structure among lakes, contributed more in explaining the functional and phylogenetic composition variations across the region, indicating dispersal constraints might strongly mediate neutral processes. The dispersal constraint could be imposed by movement barriers caused by anthropogenic landscape modification, site fidelity, or both; and 3) strong dispersal constraints could lead to competitive exclusion superimposed over neutrally assembly isolated communities, a hypothesis confirmed by the α- and β-null models. These findings provide strong support for the importance of conserving and improving ecological connectivity at the regional scale as well as habitat quality enhancement at lake scale.
Yifei Jia; Qing Zeng; Yuyu Wang; Neil Saintilan; Guangchun Lei; Li Wen. Processes shaping wintering waterbird communities in an intensive modified landscape: Neutral assembly with dispersal limitation and localized competition. Ecological Indicators 2020, 114, 106330 .
AMA StyleYifei Jia, Qing Zeng, Yuyu Wang, Neil Saintilan, Guangchun Lei, Li Wen. Processes shaping wintering waterbird communities in an intensive modified landscape: Neutral assembly with dispersal limitation and localized competition. Ecological Indicators. 2020; 114 ():106330.
Chicago/Turabian StyleYifei Jia; Qing Zeng; Yuyu Wang; Neil Saintilan; Guangchun Lei; Li Wen. 2020. "Processes shaping wintering waterbird communities in an intensive modified landscape: Neutral assembly with dispersal limitation and localized competition." Ecological Indicators 114, no. : 106330.
The degradation of wetland ecosystems is currently recognized as one of the main threats to global biodiversity. As a means of compensation, constructed wetlands (CWs), which are built to treat agricultural runoff and municipal wastewater, have become important for maintaining biodiversity. Here, we review studies on the relationships between CWs and their associated biodiversity published over the past three decades. In doing so, we provide an overview of how wildlife utilizes CWs, and the effects of biodiversity on pollutant transformation and removal. Beyond their primary aim (to purify various kinds of wastewater), CWs provide sub-optimal habitat for many species and, in turn, their purification function can be strongly influenced by the biodiversity that they support. However, there are some difficulties when using CWs to conserve biodiversity because some key characteristics of these engineered ecosystems vary from natural wetlands, including some fundamental ecological processes. Without proper management intervention, these features of CWs can promote biological invasion, as well as form an ‘ecological trap’ for native species. Management options, such as basin-wide integrative management and building in more natural wetland components, can partially offset these adverse impacts. Overall, the awareness of managers and the public regarding the potential value of CWs in biodiversity conservation remains superficial. More in-depth research, especially on how to balance different stakeholder values between wastewater managers and conservationists, is now required.
Chengxiang Zhang; Li Wen; Yuyu Wang; Cunqi Liu; Yan Zhou; Guangchun Lei. Can Constructed Wetlands be Wildlife Refuges? A Review of Their Potential Biodiversity Conservation Value. Sustainability 2020, 12, 1442 .
AMA StyleChengxiang Zhang, Li Wen, Yuyu Wang, Cunqi Liu, Yan Zhou, Guangchun Lei. Can Constructed Wetlands be Wildlife Refuges? A Review of Their Potential Biodiversity Conservation Value. Sustainability. 2020; 12 (4):1442.
Chicago/Turabian StyleChengxiang Zhang; Li Wen; Yuyu Wang; Cunqi Liu; Yan Zhou; Guangchun Lei. 2020. "Can Constructed Wetlands be Wildlife Refuges? A Review of Their Potential Biodiversity Conservation Value." Sustainability 12, no. 4: 1442.
For sustaining ecosystem functions and services, environmental conservation strategies increasingly target to maintain the multiple facets of biodiversity, such as functional diversity (FD) and phylogenetic diversity (PD), not just taxonomic diversity (TD). However, spatial mismatches among these components of biodiversity can impose challenges for conservation decisions. Hence, understanding the drivers of biodiversity is critical. Here, we investigated the global distribution patterns of TD, FD, and PD of breeding Anatidae. Using null models, we clarified the relative importance of mechanisms that influence Anatidae community. We also developed random forest models to evaluate the effects of environmental variables on the Anatidae TD, FD, and PD. Our results showed that geographical variation in Anatidae diversity is hemispheric rather than latitudinal. In the species-rich Northern Hemisphere (NH), the three diversity indices decreased with latitude within the tropical zone of the NH, but increased in the temperate zone reaching a peak at 44.5-70.0°N, where functional and phylogenetic clustering was a predominant feature. In the Southern Hemisphere (SH), Anatidae diversity increased poleward and a tendency to overdispersion was common. In NH, productivity seasonality and temperature in the coldest quarter were the most important variables. Productivity seasonality was also the most influential predictor of SH Anatidae diversity, along with peak productivity. These findings suggested that seasonality and productivity, both consistent with the energy-diversity hypothesis, interact with the varying histories to shape the contrasting hemispheric patterns of Anatidae diversity. Phylogenetic diversity (PD) and FD underdispersion, widespread across the species-rich, seasonally productive mid-to-high latitudes of the NH, reflects a rapid evolutionary radiation and resorting associated with Pleistocene cycles of glaciation. The SH continents (and southern Asia) are characterized by a widespread tendency toward PD and FD overdispersion, with their generally species-poor communities comprising proportionately more older lineages in thermally more stable but less predictably productive environments.
Qing Zeng; Julian Reid; Neil Saintilan; Matthew J. Colloff; Guangchun Lei; Li Wen. Contrasting diversity patterns of breeding Anatidae in the Northern and Southern Hemispheres. Ecology and Evolution 2019, 9, 9990 -10003.
AMA StyleQing Zeng, Julian Reid, Neil Saintilan, Matthew J. Colloff, Guangchun Lei, Li Wen. Contrasting diversity patterns of breeding Anatidae in the Northern and Southern Hemispheres. Ecology and Evolution. 2019; 9 (17):9990-10003.
Chicago/Turabian StyleQing Zeng; Julian Reid; Neil Saintilan; Matthew J. Colloff; Guangchun Lei; Li Wen. 2019. "Contrasting diversity patterns of breeding Anatidae in the Northern and Southern Hemispheres." Ecology and Evolution 9, no. 17: 9990-10003.
Debashish Mazumder; Neil Saintilan; Suzanne Hollins; Karina Meredith; Geraldine Jacobsen; Tsuyoshi Kobayashi; Li Wen. Carbon Uptake in Surface Water Food Webs Fed by Palaeogroundwater. Journal of Geophysical Research: Biogeosciences 2019, 124, 1171 -1180.
AMA StyleDebashish Mazumder, Neil Saintilan, Suzanne Hollins, Karina Meredith, Geraldine Jacobsen, Tsuyoshi Kobayashi, Li Wen. Carbon Uptake in Surface Water Food Webs Fed by Palaeogroundwater. Journal of Geophysical Research: Biogeosciences. 2019; 124 (5):1171-1180.
Chicago/Turabian StyleDebashish Mazumder; Neil Saintilan; Suzanne Hollins; Karina Meredith; Geraldine Jacobsen; Tsuyoshi Kobayashi; Li Wen. 2019. "Carbon Uptake in Surface Water Food Webs Fed by Palaeogroundwater." Journal of Geophysical Research: Biogeosciences 124, no. 5: 1171-1180.
Dryland wetlands receiving periodical floods are of key importance for ecological resilience. The inundation regime (i.e., frequency, duration, depth, and timing of inundation), is one of the major factors that determine the suitability of local conditions for specific wetland species. During droughts, inundation conditions can reach a threshold after which wetland vegetation could transition to dryland vegetation. This study analyses the response of vegetation to hydrologic variability in an arid wetland in Australia over a period of 22 years (including the Millennium drought) in order to identify inundation thresholds for transitions. We use numerical modelling, field observations and remote sensing data to relate continuous detailed simulations of the inundation regime with the response of patches of Common reed, Water couch and River red gum, three key vegetation associations in the study site. We focus in patches that were affected by the drought and presented dryland vegetation invasion as well as reference patches that remained healthy throughout the drought. On each patch, we compare annual and inter-annual simulated inundation regimes to the minimum inundation conditions that can support the specific vegetation, and we compute the percentage area of the patch that verifies minimum inundation for each year. We define this area percentage as minimum inundation index. This index is analysed in conjunction with Landsat derived information on green vegetation coverage (green Seasonal Fractional Cover) for the selected patches. We found that the minimum inundation index and inter annual frequency are able to describe the vegetation dynamics of the patches, which can be characterised by two distinct response modes that depend on a threshold value of the minimum inundation index. Inundation below the threshold noticeably leads to degraded vegetation, but the vegetation can recover quickly if this threshold is later maintained for one or two years. Values below the threshold for more extended periods (drought) result in a gradual decrease of wetland vegetation to almost complete disappearance after four years and subsequent dryland vegetation invasion.
Steven Sandi; Patricia M. Saco; Neil Saintilan; Li Wen; Gerardo Riccardi; George Kuczera; Garry Willgoose; José F. Rodríguez. Detecting inundation thresholds for dryland wetland vulnerability. Advances in Water Resources 2019, 128, 168 -182.
AMA StyleSteven Sandi, Patricia M. Saco, Neil Saintilan, Li Wen, Gerardo Riccardi, George Kuczera, Garry Willgoose, José F. Rodríguez. Detecting inundation thresholds for dryland wetland vulnerability. Advances in Water Resources. 2019; 128 ():168-182.
Chicago/Turabian StyleSteven Sandi; Patricia M. Saco; Neil Saintilan; Li Wen; Gerardo Riccardi; George Kuczera; Garry Willgoose; José F. Rodríguez. 2019. "Detecting inundation thresholds for dryland wetland vulnerability." Advances in Water Resources 128, no. : 168-182.
Most migratory birds depend on stopover sites, which are essential for refueling during migration and affect their population dynamics. In the East Asian⁻Australasian Flyway (EAAF), however, the stopover ecology of migratory waterfowl is severely under-studied. The knowledge gaps regarding the timing, intensity and duration of stopover site usages prevent the development of effective and full annual cycle conservation strategies for migratory waterfowl in EAAF. In this study, we obtained a total of 33,493 relocations and visualized 33 completed spring migratory paths of five geese species using satellite tracking devices. We delineated 2,192,823 ha as the key stopover sites along the migration routes and found that croplands were the largest land use type within the stopover sites, followed by wetlands and natural grasslands (62.94%, 17.86% and 15.48% respectively). We further identified the conservation gaps by overlapping the stopover sites with the World Database on Protected Areas (PA). The results showed that only 15.63% (or 342,757 ha) of the stopover sites are covered by the current PA network. Our findings fulfil some key knowledge gaps for the conservation of the migratory waterbirds along the EAAF, thus enabling an integrative conservation strategy for migratory water birds in the flyway.
Jialin Lei; Yifei Jia; Aojie Zuo; Qing Zeng; Linlu Shi; Yan Zhou; Hong Zhang; Cai Lu; Guangchun Lei; Li Wen. Bird Satellite Tracking Revealed Critical Protection Gaps in East Asian⁻Australasian Flyway. International Journal of Environmental Research and Public Health 2019, 16, 1147 .
AMA StyleJialin Lei, Yifei Jia, Aojie Zuo, Qing Zeng, Linlu Shi, Yan Zhou, Hong Zhang, Cai Lu, Guangchun Lei, Li Wen. Bird Satellite Tracking Revealed Critical Protection Gaps in East Asian⁻Australasian Flyway. International Journal of Environmental Research and Public Health. 2019; 16 (7):1147.
Chicago/Turabian StyleJialin Lei; Yifei Jia; Aojie Zuo; Qing Zeng; Linlu Shi; Yan Zhou; Hong Zhang; Cai Lu; Guangchun Lei; Li Wen. 2019. "Bird Satellite Tracking Revealed Critical Protection Gaps in East Asian⁻Australasian Flyway." International Journal of Environmental Research and Public Health 16, no. 7: 1147.
The accelerated rate of human‐induced environmental change poses a significant challenge for wildlife. The ability of wild animals to adapt to environmental changes has important consequences for their fitness, survival, and reproduction. Behavioural flexibility, an immediate adjustment of behaviour in response to environmental variability, may be particularly important for coping with anthropogenic change. The main aim of this study was to quantify the response of two wintering goose species (bean goose Anser fabalis and lesser white‐fronted goose Anser erythropus) to poor habitat condition at population level by studying foraging behaviour. In addition, we tested whether behavioural plasticity could alter trophic niche. We characterised foraging behaviours and calculated daily home range (HR) of the geese using global positioning system tracking data. We calculated standard ellipse areas to quantify niche width using the δ13C and δ15N values of individual geese. We linked behavioural plasticity with habitat quality using ANCOVA (analysis of covariance) models. We also tested the correlation between standard ellipse areas and HR using ANCOVA model. We found significant differences in geese foraging behaviours between years in their daily foraging area, travel distance and speed, and turning angle. Specifically, the birds increased their foraging area to satisfy their daily energy intake requirement in response to poor habitat conditions. They flew more sinuously and travelled faster and longer distances on a daily basis. For the endangered lesser white‐fronted goose, all behaviour variables were associated with habitat quality. For bean goose, only HR and turning angle were correlated with habitat quality. The birds, especially the lesser white‐fronted goose, may have had a higher trophic position under poor conditions. Our findings indicate that wintering geese showed a high degree of behavioural plasticity. However, more active foraging behaviours under poor habitat condition did not lead to a broader trophic niche. Habitat availability could be responsible to the divergent responses of foraging HR and isotopic niche to human‐induced environmental change. Therefore, maintaining natural hydrological regimes during the critical period (i.e. September–November) to ensure that quality food resources are available is central to the future of populations of geese within the East Asian–Australasian Flyway.
Jialin Lei; Yifei Jia; Yuyu Wang; Guangchun Lei; Cai Lu; Neil Saintilan; Li Wen. Behavioural plasticity and trophic niche shift: How wintering geese respond to habitat alteration. Freshwater Biology 2019, 64, 1183 -1195.
AMA StyleJialin Lei, Yifei Jia, Yuyu Wang, Guangchun Lei, Cai Lu, Neil Saintilan, Li Wen. Behavioural plasticity and trophic niche shift: How wintering geese respond to habitat alteration. Freshwater Biology. 2019; 64 (6):1183-1195.
Chicago/Turabian StyleJialin Lei; Yifei Jia; Yuyu Wang; Guangchun Lei; Cai Lu; Neil Saintilan; Li Wen. 2019. "Behavioural plasticity and trophic niche shift: How wintering geese respond to habitat alteration." Freshwater Biology 64, no. 6: 1183-1195.
Detailed vegetation maps are needed for wetland conservation and restoration as different vegetation communities have distinct water requirements. It is a continuous challenge to map the distribution of different wetland types on a regional scale, and a trade-off between the categorical details and availability of resources to ensure broad applications is often necessary for operational mapping. Here, we evaluated the capacity and performance of statistical learning in discriminating wetland types using Landsat time series and geomorphological variables computed from Light Detection and Ranging (LiDAR) and Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM). Our study showed that there was a discrimination limit of statistical learning in wetland mapping. The approach was clearly inadequate in distinguishing certain wetland types. In semiarid Australia, our results suggested that the appropriate level for floodplain wetland mapping included four classes: tree-dominated woodlands, shrublands, vegetated swamps, and non-flood-dependent terrestrial communities. Our results also demonstrated that the geomorphological metrics significantly improved the accuracy of wetland classification. Furthermore, geomorphological metrics derived from the freely available coarser resolution SRTM DEM were as beneficial for wetland mapping as those extracted from finer scale commercially-based LiDAR DEM. The finding enables the widespread applications of our approach, as both data sources are freely available globally.
Megan Powell; Grant Hodgins; Tim Danaher; Joanne Ling; Michael Hughes; Li Wen. Mapping Wetland Types in Semiarid Floodplains: A Statistical Learning Approach. Remote Sensing 2019, 11, 609 .
AMA StyleMegan Powell, Grant Hodgins, Tim Danaher, Joanne Ling, Michael Hughes, Li Wen. Mapping Wetland Types in Semiarid Floodplains: A Statistical Learning Approach. Remote Sensing. 2019; 11 (6):609.
Chicago/Turabian StyleMegan Powell; Grant Hodgins; Tim Danaher; Joanne Ling; Michael Hughes; Li Wen. 2019. "Mapping Wetland Types in Semiarid Floodplains: A Statistical Learning Approach." Remote Sensing 11, no. 6: 609.
The continuous provision of ecological services by wetlands is largely dependent on the stability of ecosystem functions such as biomass production. Biomass production is in turn strongly impacted by the frequency, duration and intensity of climate extremes such as droughts and floods. This is particularly true for the floodplain wetlands in the Murray‐Darling Basin (MDB), Australia, which exhibits high inter‐annual and inter‐decal climatic variability. In this study, we evaluated the ecological resistance and resilience to water deficit anomalies in terms of biomass production for the major woody floodplain vegetation community types (VCT) in the semi‐arid northern‐west of New South Wales including River Red Gum (Eucalyptus camaldulensis) forest, Black Box (E. largiflorens) and Coolabah (E. coolabah) woodlands, and Lignum (Duma florulenta) shrublands. Our hypothesis is that different VCTs have different trends of biomass production over time by virtue of their landscape position. Landscape position was defined by the weighted distance to water courses (DIST) and local deviation of elevation from global mean (LDFG). Biomass production stability in response to water deficit anomalies was modelled using time series (2000‐2016) of the Normalized Difference Vegetation Index (NDVI), hydrological and meteorological drought indices. We found that 1) River Red Gum forest exhibits higher resistance and resilience than other VCTs; 2) vegetation located closer to water courses has significantly higher resilience; 3) the resistance to drought indices is not significantly different across landscape positions; and 4) distance to water course is more important than topography in terms of effects on ecological resistance and resilience.
Li Wen; Megan Powell; Neil Saintilan. Landscape position strongly affects the resistance and resilience to water deficit anomaly of floodplain vegetation community. Ecohydrology 2018, 11, e2027 .
AMA StyleLi Wen, Megan Powell, Neil Saintilan. Landscape position strongly affects the resistance and resilience to water deficit anomaly of floodplain vegetation community. Ecohydrology. 2018; 11 (8):e2027.
Chicago/Turabian StyleLi Wen; Megan Powell; Neil Saintilan. 2018. "Landscape position strongly affects the resistance and resilience to water deficit anomaly of floodplain vegetation community." Ecohydrology 11, no. 8: e2027.