Browsing by Author "Wan, Ji-Zhong"

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    Assessing the habitat suitability of 10 serious weed species in global croplands
    (2020) Wang, Chun-Jing; Wan, Ji-Zhong
    Weed expansion has the potential to severely affect global agriculture. Habitat suitability models (HSMs) have been widely used to assess weed expansion to enable effective prevention and control of weeds. However, few studies have focused on the habitat suitability of global croplands for these weeds. Previous studies listed the 10 serious weed species that have the largest negative impact on global agriculture. Here, we used Maxent modeling (an HSM with good performance) to quantify the habitat suitability of global croplands for these 10 weed species using occurrence records and environmental variables (i.e., climate factors, soil properties, and human footprint). We compared the habitat suitability values of these 10 serious weed species in 174 different types of cropland. The habitat suitability values for all the weed species studied was high in global croplands. Furthermore, habitat suitability may depend on the type of cropland and the spatial variation created by varying climate factors, soil properties, and human footprint. Cynodon dactylon, Echinochloa crus-galli, Eleusine indica, Panicum maximum, and Sorghum halepense had the highest habitat suitability values in chicory plantations. Cyperus rotundus and Echinochloa colona had the highest habitat suitability values in olive plantations. The habitat suitability values for Imperata cylindrica was the highest in mustard plantations, Eichhornia crassipes was most suited to expansion in raspberry plantations, and the habitat suitability values for Lantana camara was the highest in chickpea plantations. Risk prevention and control should be based on the cropland type for these 10 serious weed species, taking into account climate factors, soil properties, and human activities. Our study provides guidelines for effective management of weed risk in different croplands globally. (C) 2020 The Author(s). Published by Elsevier B.V.
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    Biomass and nitrogen content of petiole and rachis predict leaflet trait variation in compound pinnate leaves of plants
    (2023) Wan, Ji-Zhong; Wang, Qian; Wang, Chun-Jing
    Leaf functional traits play a significant role in the functioning and services of all terrestrial ecosystems. Com-pound pinnate leaves are divided into smaller leaflets in plants. A better prediction of leaflet trait variation in compound pinnate leaves can help to understand fundamental functional mechanisms for plant leaf evolution and ecosystem from the perspective of compound pinnate leaves. Here, we explored leaflet trait variation in compound pinnate leaves of plants based on biomass and nitrogen content of both petiole and rachis. A detailed field evaluation of leaflet, petiole and rachis from 63 plant species in 364 study plots was conducted across 92 sites along an altitudinal gradient of 1700 m to 4000 m. A generalized hierarchical and variation partitioning in linear mixed modelling was utilized to explore the relationships between leaflet trait variation (i.e., leaflet area, leaflet dry mass, specific leaflet area, and leaflet nitrogen content per unit dry mass) and biomass or nitrogen content of linear elements (i.e., both petiole and rachis). The results showed that the biomass and nitrogen content of linear elements can predict leaflet trait variation in compound pinnate leaves depending on climate and phylogeny. Biomass and nitrogen content of linear elements had the strongest prediction performance on leaflet area and mass in regions with low temperature and high precipitation. Our results showed weak phylo-genetic conservatism for the prediction performance of leaf trait variation based on biomass and nitrogen content of linear elements. A potential model was developed to assess leaflet trait variation in compound pinnate leaves based on biomass and nitrogen content of linear elements. These findings will improve our understanding of functional trait variation, climate change impacts on biogeochemical cycles, and plant leaf evolution.
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    Determining key monitoring areas for the 10 most important weed species under a changing climate
    (2019) Wan, Ji-Zhong; Wang, Chun-Jing
    On a global level, weed species have a large potential to threaten ecosystems under a changing climate. The determination of key monitoring areas is an effective approach to prevent and control the spread of such species. The 10 most important weeds have been listed on a global scale. It is therefore crucial to delineate the areas with high monitoring ranks for the 10 most important weed species under climate change. We coupled conservation prioritization analysis with habitat suitability modelling to determine key monitoring areas for these species, based on different types and vulnerability levels of biomes under current and future (i.e., 2040-2069 and 2070-2099) scenarios. We determined some specific biomes (i.e., tropical and subtropical biomes, flooded grasslands and savannas, Mediterranean forests, woodlands and scrub, and mangroves) as key monitoring areas for the 10 most important weed species under a changing climate. These biomes are distributed in most regions of Latin America, the United States, Europe, central and south Africa, south and southeast Asia, southeast Australia, and New Zealand, including large vulnerable ecoregions. Tropical and subtropical grasslands, savannas, and shrublands were particularly vulnerable, because these biomes had the largest area with a high monitoring rank, and this rank was predicted to further increase in the near future. Our study highlights the importance of effective management strategies for the prevention and control of these species across different biomes on a global scale. (C) 2019 Elsevier B.V. All rights reserved.
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    Effects of agricultural lands on the distribution pattern of genus diversity for neotropical terrestrial vertebrates
    (2021) Wang, Chun-Jing; Wan, Ji-Zhong; Fajardo, Javier
    The expansion and intensification of agricultural lands (i.e., croplands and pasture areas) have become increasing threats to species diversity around the world. However, genus diversity should be considered for biodiversity conservation due to the important role that phylogenetic diversity and evolutionary history play shaping biodiversity patterns, particularly in the Neotropics, the most species-rich realm. Here, we explored agricultural land effects on distribution patterns of terrestrial vertebrate diversity at the genus level using cases from the Neotropics. We compiled distribution data on genera of amphibians, birds, mammals, and reptiles and explored the effects of agricultural lands on genus diversity distribution patterns for terrestrial vertebrates in the region using distribution modelling. Geography Weighting Regression (GWR) was used to explore the spatially variable relationship between agricultural lands and genus diversity. We found that there are significant, nonstationary relationships between agricultural lands and genus diversity in the Neotropics. The non-stationary relationship between croplands and genus diversity was stronger than that between pasture areas and genus diversity. Furthermore, these effects may depend on changes in genus groups (i.e., amphibians, birds, mammals, and reptiles) and biomes. The relationship was the strongest for the croplands and reptile diversity pair at the genus levels. The relationship between both croplands and pasture areas and reptile diversity was the largest in temperate broadleaf and mixed forests. Given the influence of crop and pasturelands on vertebrate distribution patterns, we argue that agriculture development should be considered in the spatial prioritization of conservation for vertebrates in the Neotropics. Agricultural lands should be used as environmental variables for distribution modelling, and understanding the impacts of agricultural lands on biodiversity is critical for effective conservation management in the Neotropics.
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    Effects of soil properties on the spatial distribution of forest vegetation across China
    (2019) Wan, Ji-Zhong; Yu, Jing-Hua; Yin, Guang-Jing; Song, Zuo-Min; Wei, Deng-Xian; Wang, Chun-Jing
    The investigation of factors affecting the spatial distribution of forest vegetation on a large scale is a hot topic in forestry and ecology. Numerous studies have reported that climate and human activities have a considerable effect on the spatial distribution of forest vegetation. However, few studies have focused on the effects of soil properties on the spatial distribution of forest vegetation across China. In the present study two indicators were used to explore such soil effects, namely the percentage contribution of soil properties to the spatial distribution of forest vegetation and the similarity of the potential distributions based on climate variables and both climate and soil variables under distribution modelling. We found that 1) soil parameters (e.g., coarse fragment volume and organic carbon stock) contribute to the spatial distribution of forest vegetation in China, although this contribution may vary among different biomes and vegetation classes and 2) the spatial distribution of forest vegetation differs among the different vegetation classes and biomes. Furthermore, soil variables (e.g., coarse fragment volume and organic carbon stock) could play an important role in the spatial distribution of conifer-broadleaf forest vegetation and mountain broad-leaved and conifer-leaved forest vegetation. However, climate variables were more important than soil properties across most vegetation types. It is therefore suggested that 1) coarse fragment volume and organic carbon stock should be used as indicators to monitor forest vegetation and 2) soil properties should be conserved to facilitate reforestation programs in China. The present study provides evidence that soil parameters affect the spatial distribution of forest vegetation in China, facilitating the development of effective management strategies. (C) 2019 The Authors. Published by Elsevier B.V.
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    Environmental heterogeneity as a driver of terrestrial biodiversity on a global scale
    (2023) Wan, Ji-Zhong; Wang, Chun-Jing; Marquet, Pablo A.
    To improve the effectiveness of biodiversity conservation and risk assessments under global changes, it is necessary to understand the drivers of terrestrial biodiversity on a global scale. Environmental heterogeneity is an important umbrella term for different environmental factors that contribute to species diversity. Previous studies have shown that there are significant relationships between geodiversity and biodiversity on a global scale, and that heterogeneity in geodiversity features and environmental variables, that is indicators of environmental heterogeneity (EH), drive biodiversity at local and regional scales. However, we do not yet know how terrestrial biodiversity is maintained, how well represented are the different taxa, and where would they be more at risks considering their abundances and diversities. In this study, we quantified EH of climate, topography, and land cover. We used four theoretical indexes (i.e., Fisher's alpha, Shannon's H, Hurlbert's PIE, and Good's u) to quantify terrestrial biodiversity based on abundance and diversity. We used regression models to explore the relationships between environmental heterogeneity and terrestrial biodiversity across different organismic groups (ants, bats, birds, butterflies, frogs, ground beetles, mosquitoes, odonates, orthopterans, rodents, scarab beetles, and trees) globally. We found significant relationships between environmental heterogeneity and terrestrial biodiversity, particularly for trees across the three EH components (climate, topography, and land cover), however, the effects of environmental heterogeneity on terrestrial biodiversity may vary among different groups of organisms. Land cover EH could affect the terrestrial biodiversity for ants, bats, birds, butterflies, frogs, mosquitoes, odonates, orthopterans, rodents, and scarab beetles. Furthermore, there were significant relationships between topographic EH and the terrestrial biodiversity for bats, butterflies, ground beetles, odonates, and trees. Climatic EH had significant effects on the terrestrial biodiversity for all organism groups. Our study provides new insights into biodiversity conservation by considering the terrestrial biodiversity based on EH, an indicator of geodiversity.
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    HISTORICAL AND CONTEMPORARY CLIMATE LEGACY OF THE LARGE-SCALE DISTRIBUTIONAL PATTERNS OF PLANT RICHNESS ACROSS DIFFERENT TAXONOMIC LEVELS: AN ASSESSMENT OF PROTECTED AREAS IN CHINA
    (2019) Wang, Chun-Jing; Wan, Ji-Zhong
    Background: Historical and contemporary climates may shape the distributional patterns of plant species richness across different scales. However, few studies have focused on the effects of historical and contemporary climate changes on the distributional patterns of plant richness in Chinese protected areas across different taxonomic levels.
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    Identifying key monitoring areas for tree insect pest risks in China under climate change
    (2024) Zhang, Fei-Xue; Li, Hong-Li; Wan, Ji-Zhong; Wang, Chun-Jing
    Climate change can exacerbate pest population growth, posing significant threats to ecosystem functions and services, social development, and food security. Risk assessment is a valuable tool for effective pest management that identifies potential pest expansion and ecosystem dispersal patterns. We applied a habitat suitability model coupled with priority protection planning software to determine key monitoring areas (KMA) for tree insect pest risks under climate change and used forest ecoregions and nature reserves to assess the ecological risk of insect pest invasion. Finally, we collated the prevention and control measures for reducing future pest invasions.The KMA for tree insect pests in our current and future climate is mainly concentrated in eastern and southern China. However, with climate change, the KMA gradually expands from southeastern to northeastern China. In the current and future climate scenarios, ecoregions requiring high monitoring levels were restricted to the eastern and southern coastal areas of China, and nature reserves requiring the highest monitoring levels were mainly distributed in southeastern China.Tree insect pest invasion assessment using ecoregions and nature reserves identified that future climates increase the risk of pest invasions in forest ecoregions and nature reserves, especially in northeastern China.The increased risk and severity of tree insect pest invasions require implementing monitoring and preventative measures in these areas. We effectively assessed the pest invasion risks using forest ecoregions and nature reserves under climate change. Our assessments suggest that monitoring and early prevention should focus on southeastern and northeastern China.
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    Identifying potential distributions of 10 invasive alien trees: implications for conservation management of protected areas
    (2018) Wan, Ji-Zhong; Zhang, Zhi-Xiang; Wang, Chun-Jing
    Tree invasion has the potential to negatively affect biodiversity and ecosystems, with invasive alien trees (IATs) expanding widely in protected areas (PAs) across different habitats. Thus, the effectiveness of PAs might be reduced. Investigation of the distributions of IAT is urgently required to improve the effective conservation management of PAs. We projected the potential distributions of 10 IATs, which included Acacia mearnsii, Ardisia elliptica, Cecropia peltata, Cinchona pubescens, Leucaena leucocephala, Melaleuca quinquenervia, Miconia calvescens, Morella faya, Prosopis glandulosa, and Spathodea campanulata, that have a serious influence on global biodiversity and assessed the distribution possibilities of these IATs in PAs based on the PA categories of the International Union for Conservation of Nature (IUCN). The overall potential distributions of these 10 IATs included Latin America, central and southern Africa, southeastern Asia, eastern Australia and New Zealand, and western Europe. Annual mean temperature, temperature seasonality, annual precipitation, and soil bulk density were found to be important environmental variables for the potential distributions of these IATs. Overall, A. mearnsii, A. elliptica, C. peltata, L. leucocephala, M. quinquenervia, M. calvescens, and S. campanulata were distributed mainly in the IUCN PA categories of national parks and PAs with sustainable use of natural resources. We proposed the following for conservation management of PAs: (1) completion of species inventories for PAs, (2) better understanding of factors driving invasions in PAs, (3) assessment of the efficiency of management within particular PAs, and (4) evaluation of changes in trends regarding plant invasions in PAs under climate change conditions.
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    Legacy effects of historical woodland changes on contemporary plant functional composition
    (2023) Wan, Ji-Zhong; Wang, Chun-Jing
    Considering the legacy of plant functional composition can help assess ecosystem functions and ecosystem services across different spatial scales under land cover changes. Woody plants likely respond to natural and anthropogenic perturbations due to historical events (e.g., agricultural development), thus contemporary plant functional composition may be explained by historical woodland change, a type of land cover change. We propose that historical woodland changes may have legacy effects on contemporary plant functional composition. Here, we used partial least squares regression and linear mixed model analyses to test this assumption by coupling data on community weighted means (CWM) and community weighted variance (CWV) of vegetation plots and calculating the time of woodland existence across different periods from AD 0 to 2017. We found that the legacy effects of historical land cover changes on CWM and CWV during the existence time of woodland, particularly from AD 0 to 900, were drivers of contemporary plant functional composition at large spatial scales. Furthermore, historical woodland changes can affect contemporary plant functional composition, depending on the biome type. Particularly, the CWM of plant height, seed mass, and seed length showed the strongest correlations with woodland changes from AD 1910 to 2010 in tropics with year-round rain, and the CWM of leaf traits correlated with woodland changes from AD 0 to 1700 in tropics with summer rain. Our study provides the effective evidence on the legacy of historical woodland changes and the effects on contemporary plant functional composition, which is crucial with respect to effective management of plant diversity and assessing ecosystem functions and services from local to global scales over time.
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    Plant functional composition as an effective surrogate for biodiversity conservation
    (2024) Wan, Ji-Zhong; Pellissier, Loic; Wang, Chun-Jing; Yu, Fei-Hai; Li, Mai-He
    In biodiversity conservation frameworks, determining surrogates for biodiversity is crucial for improving the effectiveness of biodiversity conservation and management. As plant functional composition can indicate variations in ecosystem functions and services, it could be used as an effective surrogate in biodiversity conservation planning. However, to the best of our knowledge, this metric has been rarely used in biodiversity conservation planning. To explore whether plant functional composition can be used as an effective surrogate for biodiversity conservation, we used a linear mixed regression model to investigate the relationships between plant functional composition (i.e., community-weighted means (CWMs) from the sPlot database) and the species richness of birds, mammals, and amphibians, and between plant functional composition and terrestrial conservation priority ranks (considering biodiversity conservation alone, or biodiversity, carbon, and water conservation together). Thereafter, we quantified the changing trends in these relationships across biomes using the least square method. We found that CWMs significantly affected species richness and terrestrial conservation priority ranks, based on the marginal R2 and conditional R2 values from the linear mixed regression model. Further, CWMs significantly affected species richness and terrestrial conservation priority ranks across different biomes of forests and shrublands. However, the nature of these effects (i.e., positive or negative) was dependent on biome type. These results suggest that functional composition can be considered as a biodiversity surrogate for conservation planning, and that biome-specific relationships should be considered.
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    Spatial prioritization for the conservation of terrestrial vertebrate genera in the Neotropics
    (2023) Wan, Ji-Zhong; Wang, Chun-Jing
    Vertebrate genera should be considered for spatial conservation prioritisation due to their importance in terms of intrinsic values for biodiversity maintenance and conservation, which were closely associated with phylogenetic diversity. We conducted spatial conservation prioritisation for Neotropical terrestrial vertebrate genera. We used species distribution modelling to project the vertebrate distributions at the species and genus levels based on a set of both past and current climate variables. The zonation framework was then applied to conduct spatial conservation prioritisation for Neotropical vertebrates based on the distribution probabilities of different genus groups (all genera, amphibians, birds, mammals, and reptiles). The largest priority conservation areas for terrestrial vertebrate genera, including amphibians, birds, mammals, and reptiles, were in ecoregions belonging to the tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands, savannas, and shrublands. Conservation gaps persist in existing protected area networks, and the identified priority areas should complement existing protected areas to address these gaps. We recommend the protected area network for the key ecoregions for vertebrate conservation identified in this study, but this requires interventions by all governments in the Neotropical Region. Our study offers new insights into the use of a conservation planning framework coupled with genus distribution from an application perspective.
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    Vulnerability of global forest ecoregions to future climate change
    (2019) Wang, Chun-Jing; Zhang, Zhi-Xiang; Wan, Ji-Zhong
    The vulnerability of global forest ecoregions to future climate change represents a major threat to biodiversity and ecosystems worldwide. Therefore, it is important to investigate this vulnerability to improve the global conservation management network for biodiversity and ecosystems. We used speciesearea relationship coupled with correlative distribution modelling to conduct a global vulnerability assessment on 387 forest ecoregions under future climate change across different (1) biomes, (2) biogeographical realms and (3) conservation statuses. We found that 8.8% of global forest ecoregions were highly vulnerable in a low-greenhouse-gas-concentration scenario, and 32.6% of the global forest ecoregions were highly vulnerable in the high-greenhouse-gas-concentration scenario. Furthermore, the overall vulnerability of forest ecoregions was significantly greater for the high-rather than the low-greenhouse-gas-concentration scenario. In particular, critical or endangered forest ecoregions of Temperate Broadleaf and Mixed Forests, Temperate Conifer Forests, Tropical and Subtropical Dry Broadleaf Forests and Tropical and Subtropical Moist Broadleaf Forests were highly vulnerable in Nearctic, Neotropic and Palearctic realms. Furthermore, relatively stable and intact Tropical and Subtropical Moist Broadleaf Forests may be threatened in Neotropic and Afrotropic realms due to their climate change vulnerability. Hence, due to increasing greenhouse gas concentrations, future climate change must be incorporated into forest ecoregion conservation management to improve the effectiveness of global conservation network systems for biodiversity and ecosystems. (c) 2019 The Authors. Published by Elsevier B.V.