Invasive species are considered as one of the key threats to biodiversity and human livelihoods g... more Invasive species are considered as one of the key threats to biodiversity and human livelihoods globally. The most effective strategy for handling invasion would be based on profiling invasive species and identifying areas at risk of invasion before they occur. The current study used a trait-environment modelling approach to identify alien species with high probability of invasiveness and combined this with the species distribution models (SDMs) to predict areas in the arid Saint Katherine Protectorate (SKP) in Egypt that were at highest risk of invasion by these species. The specific leaf area, number of leaves, soil nitrogen, and prevalence of disturbances were the most important biotic and abiotic indicators for predicting invasiveness in SKP. Of the investigated 33 alien plant species, three species were identified to have the highest probability of invasiveness, including Salvia rosmarinus, Eucalyptus globulus, and Acacia saligna. The outcome of the SDMs revealed that precipitation seasonality and temperature-related variables were the most important bioclimatic predictors determining the potential invasion risk of the studied alien species. Potential invasion is more likely in the eastern and northern parts of SKP, where biodiversity-rich common microhabitats are found and where there is a prevalence of disturbances such as tourism activities. The Etalaa, Shaq Mosa, and El-Mesirdi wadis microhabitats, in particular, were identified in the current study to be potentially highly suitable microhabitats for alien invasiveness and should be prioritized for monitoring and conservation actions. Moreover, the three identified species could be used as early indicators for microhabitats at risk of invasion along the environmental gradients of temperature and precipitation in arid ecosystems. This approach can be applied to other taxa and other ecosystems and can provide opportunities for formulating proactive management strategies against biological invasions.
Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP... more Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP) is crucial for biodiversity conservation and for predicting future anthropogenic impacts on ecosystems. Here, we collected Quaternary paleo-, palynological, and phylogeographical records from across the TP and applied ecological niche models (ENMs) to obtain a profound understanding of the different adaptation strategies and distributional changes in Abies trees in this unique area. We identified environmental variables affecting the different historical biogeographies of four related endemic Abies taxa and rebuilt their distribution patterns over different time periods, starting from the late Pleistocene. In addition, modeling and phylogeographic results were used to predict suitable refugia for Abies forrestii, A. forrestii var. georgei, A. fargesii var. faxoniana, and A. recurvata. We supplemented the ENMs by investigating pollen records and diversity patterns of cpDNA for them. The overall reconstructed distributions of these Abies taxa were dramatically different when the late Pleistocene was compared with the present. All Abies taxa gradually receded from the south toward the north in the last glacial maximum (LGM). The outcomes showed two well-differentiated distributions: A. fargesii var. faxoniana and A. recurvata occurred throughout the Longmen refuge, a temporary refuge for the LGM, while the other two Abies taxa were distributed throughout the Heqing refuge. Both the seasonality of precipitation and the mean temperature of the driest quarter played decisive roles in driving the distribution of A. fargesii var. faxoniana and A. recurvata,
In Egypt, monitoring and assessing the changes in natural biodiversity by the traditional site-ba... more In Egypt, monitoring and assessing the changes in natural biodiversity by the traditional site-based methods involve considerable effort and costs. Alternatively, remote sensing can be used as a promising technique to provide complete coverage of habitat, and vegetation species at a specific study area over a given period. Hence, this chapter considers the state-of-the-art of remote sensing for mapping the environmental variables at different locations in Egypt, including deserts, oases, sand dunes, saltmarshes, fish farms, reed vegetation, and agricultural lands. Moreover, the detections of land use/land cover (LULC), soil properties, spatial rainfall distribution, and surface runoff, as well as the management of flood and water resources, by geographical information systems (GIS) were demonstrated. The chapter undertakes useful information and knowledge about the Egyptian environment, giving multiple benefits to researchers, policy planners, and stakeholders. The study objectives are illustrated regarding previous articles reported in the literature.
The role of heritage sites as a shelter for biodiversity is overlooked. Eight archeological sites... more The role of heritage sites as a shelter for biodiversity is overlooked. Eight archeological sites representing different landscapes in Alexandria City were surveyed, from which 59 stands were sampled between April 2019 and March 2021. The archeological sites and the relictual landscapes are geographically dispersed and are arranged here from west to east, representing the full range of environmental variation within the study area. The selection of stands in each site was based on the area and the variability within the habitats, the physiography, and the levels of disturbance. A composite soil sample was collected from each site. Two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DECORANA) were carried out to identify the plant communities in the study area. The recorded taxa, their national geographical distribution, life forms, habitats, chorological types, and vegetation groups are listed. A total of 221 specific taxa, 172 native and 49 alien no...
The Regional Assessment Report on Biodiversity and Ecosystem Services for Africa produced by the ... more The Regional Assessment Report on Biodiversity and Ecosystem Services for Africa produced by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) provides a critical analysis of the state of knowledge regarding the importance, status, and trends of biodiversity and nature's contributions to people. The assessment analyses the direct and underlying causes for the observed changes in biodiversity and in nature's contributions to people, and the impact that these changes have on the quality of life of people. The assessment, finally, identifies a mix of governance options, policies and management practices that are currently available to reduce the loss of biodiversity and of nature's contributions to people in that region. The assessment addresses terrestrial, freshwater, and coastal biodiversity and covers current status and trends, going back in time several decades, and future projections, with a focus on the 2020-2050 period.<...
The application of species distribution modeling in deserts is a useful tool for mapping species ... more The application of species distribution modeling in deserts is a useful tool for mapping species and assessing the impact of human induced changes on individual species. Such applications are still rare, and this may be attributed to the fact that much of the arid lands and deserts around the world are located in inaccessible areas. The current study is the first to conduct spatially explicit modeling of plant species distribution in Egypt. The random forest modeling approach was applied to climatic and land-surface parameters to predict the distribution of selected important plant species in an arid landscape in the northwestern coastal desert of Egypt. The impact of changes in land use and climate on the distribution of the plant species was assessed. The results indicate that the changes in land use in the area over the last 23 years have resulted in habitat loss for all the modeled species. Projected future changes in land use reveals that all the modeled species will continue to suffer habitat loss. The projected impact of modeled climate scenarios (A1B, A2A and B2A) on the distribution of the modeled species by 2040 varied. Some of the species were projected to be adversely affected by the changes in climate, while other species are expected to benefit from these changes. The combined impact of the changes in land use and climate pose serious threats to most of the modeled species. The study found that all the species are expected to suffer loss in habitat, except Gymnocarpos decanderus. The study highlights the importance of assessing the impact of land use/climate change scenarios on other species of restricted distribution in the area and can help shape policy and mitigation efforts to protect and preserve biodiversity in desert of Egypt. : climate change scenarios, arid lands, plant species, land use change, Egypt environmental factors control the distribution of species and consequently communities (Franklin 1995; Guisan & Zimmermann 2000; Guisan & Thuiller 2005). Prediction of species distribution started early on by descriptive studies conducted by ecologists interested in understanding the relationship between patterns of species in relation to geographical settings and environmental gradients (Elith & Leathwick 2009). Later the evolution in ecology and other related fields coupled by the emergence of numerical analysis and quantitative approaches greatly influenced species distribution modeling. According to Elith & Leathwick (2009) quantitative approaches of species distribution modeling developed as a result of convergence of two lines of research trends in ecology and geography. The first line started in ecology as field-based research that studied species-habitat relationships. These studies later adopted quantitative approaches by applying statistical analysis techniques (e.g. linear multiple regression techniques), then the advanced regression techniques (e.g. Generalized Liner Models (GLMs) and boosted regression techniques) were developed to overcome limitations of the linear paradigm. The second line emerged in geography, and specifically in physical geography, through the advancement in geographic information systems and remote sensing techniques. The integration of GIS and remote sensing has allowed the development of methods for interpolation of global climate and modeling global surface elevation, in addition to provision of spectral data that were employed in species prediction models. The development of the field of species distribution modeling and mapping has been driven by the need to map vegetation patterns over large areas for resource management, conservation planning, and to predict the effects of environmental changes on vegetation distribution (Franklin 1995; Guisan & Thuiller 2005). A number of statistical and, more recently, machine-learning methods have been developed for conducting SDM over the last two decades . A review of species distribution modeling techniques and approaches used can be found in Franklin (1995), , Guisan & Thuiller (2005), Elith & Leathwick (2009. Although there are many approaches used for the species distribution modeling, no rules exist to provide guidelines on which is the best modeling approach to use (Franklin 2009). It is also likely that some approaches may be better for prediction of one species over others. This is related to many factors that include: the nature of the data used (quantity & quality); the nature of the predicator variables used; the spatial scale used (resolution and the extent); and the relevance of the environmental predicators used to the ecological characteristics of the species being predicted (
Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regi... more Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regions. Understanding driving forces affecting the potential global distribution would help in managing its current and future spread. The role of climate on the global spatial distribution of P. juliflora has been well studied, but little is known about the role of soil and human impacts as potential drivers. Here, we used maximum entropy (MaxEnt) for species distribution modelling to understand the role of climate (C), soil (S) and human impacts (H), C+S, and C+S+H in controlling the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quart...
Climate change is an important driver of biodiversity loss and extinction of endemic montane spec... more Climate change is an important driver of biodiversity loss and extinction of endemic montane species. In China, three endemic Juniperus spp. (Juniperuspingii var. pingii, J.tibetica, and J.komarovii) are threatened and subjected to the risk of extinction. This study aimed to predict the potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explai...
The eastern coastal area of the Arabian Peninsula is subject to overgrazing, agricultural activit... more The eastern coastal area of the Arabian Peninsula is subject to overgrazing, agricultural activities, oil pollution and urban encroachments. These activities cause habitat destruction and may have changed species composition. The current study aimed at assessing conservation and ethnobotanical importance of plants and how they are affected by environmental threats. The natural vegetation composition was studied and the ethnobotanical relative importance (RI) index and the species conservation index (SCI) were calculated. The results showed that native plants provide many ecological and socioeconomic services, including the provisioning of food, medicine, and energy. The native species (&gt;77%) were reported to potentially be used for more than 170 therapeutic applications and for curing various human ailments. The medicinal plants (15%) attained RI value &gt;50% reflecting high versatility and importance in local pharmacopeia. The number of threats to species showed significant positive association with SCI index and insignificant positive association with RI index. The study indicated that the current human activities may have negatively impacted provisioning of ecosystem services especially those offered by native plants. The ability of the natural ecosystems to sustainably provide services will be enhanced by adoption of land management practices that restore species and reduce pressure on native plants.
Remote Sensing Applications: Society and Environment
Abstract Human activities cause introduction of alien species to new areas, which may cause serio... more Abstract Human activities cause introduction of alien species to new areas, which may cause serious problems and threats to biodiversity and ecosystem services. Omayed biosphere reserve (OBR) at the northwestern desert of Egypt, recognized for its rich flora, has recently encountered new human-induced disturbances. The current study sought to identify alien species that might have invaded OBR as a result of such activities; and to estimate the area affected by alien species using remotely-sensed data. Field surveys of 300 sampling plots representing different habitats were conducted from spring 2011 to spring 2014, whereby occurrences of alien plant species were recorded. We evaluated the use of combined environmental and remotely-sensed data for developing predictive distribution models for 21 alien species recorded in the area using Maxent modeling technique. The inclusion spectral predictors with other environmental predictors has improved the performance of the distribution models (mean test AUC 0.88 ± 0.06) for most of the alien species. Environmental variables that contributed the most to prediction of alien species distribution included soil, elevation and slope; in addition to predictors that represented disturbance proxies such as distance from irrigation canals and distance from roads. The results revealed that more than 40% of the area is predicted to be infested by at least one alien species. Results also manifest the merit of incorporating remotely-sensed data in prediction of alien species distribution, which hold promise for development of proactive management approaches to identify and control areas of high infestation of alien species and prevent further spread of invasive plants.
Robust classification approaches are required for accurate classification of complex land-use/lan... more Robust classification approaches are required for accurate classification of complex land-use/land-cover categories of desert landscapes using remotely sensed data. Machine-learning ensemble classifiers have proved to be powerful for the classification of remotely sensed data. However, they have not been evaluated for classifying land-cover categories in desert regions. In this study, the performance of two machine-learning ensemble classifiers – random forests (RF) and boosted artificial neural networks – is explored in the context of classification of land use/land cover of desert landscapes. The evaluation is based on the accuracy of classification of remotely sensed data, with and without integration of ancillary data. Landsat-5 Thematic Mapper data captured for a desert landscape in the north-western coastal desert of Egypt are used with ancillary variables derived from a digital terrain model to classify 13 different land-use/land-cover categories. Results show that the two ensemble methods produce accurate land-cover classifications, with and without integrating spectral data with ancillary data. In general, the overall accuracy exceeded 85% and the kappa coefficient (κ) attained values over 0.83. The integration of ancillary data improved the performance of the boosted artificial neural networks by approximately 5% and the random forests by 9%. The latter showed overall higher accuracy; however, boosted artificial neural networks showed better generalization ability and lower overfitting tendencies. The results reveal the merit of applying ensemble methods to integrated spectral and ancillary data of similar desert landscapes for achieving high classification accuracies.
Quantitative approaches used for detecting biodiversity ‘hotspots’ depend mostly on species occur... more Quantitative approaches used for detecting biodiversity ‘hotspots’ depend mostly on species occurrence data. This approach has been criticized for not recognizing all aspects of species importance. In this study, we used information on plant species to estimate a species conservation importance (SCI) and compare sites’ conservation value (SCV) at the landscape level with regard to plant species. The SCI index assesses vascular plant significance based on inclusion of many criteria accounting to various aspects of species importance. The SCI index was calculated for the 405 plant species recorded in a northwestern coastal desert landscape, and two protected areas in Egypt. The Comparison revealed that despite having the highest number of species, the northwestern coastal desert landscape ranked third to the other protected areas based on SCV. For highlighting ‘hotspots’ of conservation priority regarding vascular plants in the northwestern coastal desert landscape, the Getis-Ord Gi* hotspot geostatistical analyses were applied to the per-plot number of species, maximum SCI, average SCI (ACI), and SCV values of 827 sampled plots. The results revealed the occurrence of significant hotspots for plant conservation at the south of the landscape. The application of Getis-Ord Gi* geostatistical analysis to conservation indices promises to be a useful tool in identification of hotspots at the landscape level. The approach used in the current study will help in comparing and ranking regions according plant species conservation priorities. It can also be used for guiding site selection efforts regarding plant species conservation particularly in similar ecosystems.
ABSTRACT Abstract Detecting land-use change has become of concern to environmentalists, conservat... more ABSTRACT Abstract Detecting land-use change has become of concern to environmentalists, conservationists and land use planners due to its impact on natural ecosystems. We studied land use/land cover (LULC) changes in part of the northwestern desert of Egypt and used the Markov-CA integrated approach to predict future changes. We mapped the LULC distribution of the desert landscape for 1988, 1999, and 2011. Landsat Thematic Mapper 5 data and ancillary data were classified using the random forests approach. The technique produced LULC maps with an overall accuracy of more than 90%. Analysis of LULC classes from the three dates revealed that the study area was subjected to three different stages of modification, each dominated by different land uses. The use of a spatially explicit land use change modeling approach, such as Markov-CA approach, provides ways for projecting different future scenarios. Markov-CA was used to predict land use change in 2011 and project changes in 2023 by extrapolating current trends. The technique was successful in predicting LULC distribution in 2011 and the results were comparable to the actual LULC for 2011. The projected LULC for 2023 revealed more urbanization of the landscape with potential expansion in the croplands westward and northward, an increase in quarries, and growth in residential centers. The outcomes can help management activities directed toward protection of wildlife in the area. The study can also be used as a guide to other studies aiming at projecting changes in arid areas experiencing similar land use changes.
Panicum turgidum is one of the most drought resistant plants in the Egyptian desert. Five habitat... more Panicum turgidum is one of the most drought resistant plants in the Egyptian desert. Five habitat types were selected for the study: sand dunes (North Sinai and in Wady El-Natrun), gravel desert, coastal plain, and water runnels of a wadi bed (South Sinai and Eastern Desert). About 47.4% of the studied sites were subjected to high grazing pressure, 26.3% to moderate grazing pressure; the remaining 26.3% were subjected to low grazing pressure. Concentration of the nutrients (K, Na, Ca, P and Ca/P ratio) in the grazeable parts of P. turgidum populations exhibited insignificant variability between habitats and phytogeographical regions. Meanwhile, concentration of potassium showed significant variability between the phytogeographical regions. Ca/P ratio of the grazeable parts of P. turgidum was significantly related to the soil silt and organic matter content. The percentage of crude protein was higher than the minimum required for the maintenance of the grazing animals, i.e. P. turgidum has a good or excellent forage quality. Due to its high nutritive value and ease of cultivation, P. turgidum grains could be considered as a potential crop, which may serve as a supplementary food to the common cereals. It worth noting that the variation in the nutritive values among the cultivated populations was insignificant as all the cultivated populations had a high nutritive value, indicating the effect of edaphic factors on the wild population nutritive value which was proved also from the correlation between the edaphic factors and nutritive variable.
Simple Summary Intra-city railway areas can play a role in enhancing the diversity and dynamics o... more Simple Summary Intra-city railway areas can play a role in enhancing the diversity and dynamics of urban flora. The current study sheds the light on the role that overlooked railway habitats can provide in the conservation of biodiversity through surveying the floristic composition and diversity along intra-city railway and tram tracks in Alexandria. The plant communities were identified using multivariate analysis techniques. Spontaneous flora in intra-city railway areas represent distinct adaptations to unique urban–industrial ecosystems with different levels of anthropogenic disturbance. Despite the high level of disturbance, native species dominated the investigated habitats, including rare and endemic species. The study emphasizes the role that these ruderal habitats provide as valuable refuge areas for rare and endangered species worthy of proper management and conservation action. Abstract Intra-city railway areas are deemed large greenspaces and are believed to be key in enh...
Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP... more Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP) is crucial for biodiversity conservation and for predicting future anthropogenic impacts on ecosystems. Here, we collected Quaternary paleo-, palynological, and phylogeographical records from across the TP and applied ecological niche models (ENMs) to obtain a profound understanding of the different adaptation strategies and distributional changes in Abies trees in this unique area. We identified environmental variables affecting the different historical biogeographies of four related endemic Abies taxa and rebuilt their distribution patterns over different time periods, starting from the late Pleistocene. In addition, modeling and phylogeographic results were used to predict suitable refugia for Abies forrestii, A. forrestii var. georgei, A. fargesii var. faxoniana, and A. recurvata. We supplemented the ENMs by investigating pollen records and diversity patterns of cpDNA for them. The overall reconstructed distributions of these Abies taxa were dramatically different when the late Pleistocene was compared with the present. All Abies taxa gradually receded from the south toward the north in the last glacial maximum (LGM). The outcomes showed two well-differentiated distributions: A. fargesii var. faxoniana and A. recurvata occurred throughout the Longmen refuge, a temporary refuge for the LGM, while the other two Abies taxa were distributed throughout the Heqing refuge. Both the seasonality of precipitation and the mean temperature of the driest quarter played decisive roles in driving the distribution of A. fargesii var. faxoniana and A. recurvata, respectively; the annual temperature range was also a key variable that explained the distribution patterns of the other two Abies taxa. Different adaptation strategies of trees may thus explain the differing patterns of distribution over time at the TP revealed here for endemic Abies taxa.
Climate change is an important driver of biodiversity loss and extinction of endemic montane spec... more Climate change is an important driver of biodiversity loss and extinction of endemic montane species. In China, three endemic Juniperus spp. (Juniperus pingii var. pingii, J. tibetica, and J. komarovii) are threatened and subjected to the risk of extinction. This study aimed to predict the potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explaining the potential distribution of these three Juniperus species; they contribute by 16–56.1% and 20.4–38.3%, respectively. Accounting for the use of different thresholds provides a balanced approach for species distribution models’ applications in conservation assessment when the goal is to assess potential climatic suitability in new geographical areas. Therefore, south Sichuan and north Yunnan could be considered important priority conservation areas for in situ conservation and search for unknown populations of these three Juniperus species.
Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regi... more Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regions. Understanding driving forces affecting the potential global distribution would help in managing its current and future spread. The role of climate on the global spatial distribution of P. juliflora has been well studied, but little is known about the role of soil and human impacts as potential drivers. Here, we used maximum entropy (MaxEnt) for species distribution modelling to understand the role of climate (C), soil (S) and human impacts (H), C+S, and C+S+H in controlling the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest risk of invasion than other moist biomes.
Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regi... more Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regions. Understanding driving forces affecting the potential global distribution would help in managing its current and future spread. The role of climate on the global spatial distribution of P. juliflora has been well studied, but little is known about the role of soil and human impacts as potential drivers. Here, we used maximum entropy (MaxEnt) for species distribution modelling to understand the role of climate (C), soil (S) and human impacts (H), C+S, and C+S+H in controlling the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest risk of invasion than other moist biomes.
Invasive species are considered as one of the key threats to biodiversity and human livelihoods g... more Invasive species are considered as one of the key threats to biodiversity and human livelihoods globally. The most effective strategy for handling invasion would be based on profiling invasive species and identifying areas at risk of invasion before they occur. The current study used a trait-environment modelling approach to identify alien species with high probability of invasiveness and combined this with the species distribution models (SDMs) to predict areas in the arid Saint Katherine Protectorate (SKP) in Egypt that were at highest risk of invasion by these species. The specific leaf area, number of leaves, soil nitrogen, and prevalence of disturbances were the most important biotic and abiotic indicators for predicting invasiveness in SKP. Of the investigated 33 alien plant species, three species were identified to have the highest probability of invasiveness, including Salvia rosmarinus, Eucalyptus globulus, and Acacia saligna. The outcome of the SDMs revealed that precipitation seasonality and temperature-related variables were the most important bioclimatic predictors determining the potential invasion risk of the studied alien species. Potential invasion is more likely in the eastern and northern parts of SKP, where biodiversity-rich common microhabitats are found and where there is a prevalence of disturbances such as tourism activities. The Etalaa, Shaq Mosa, and El-Mesirdi wadis microhabitats, in particular, were identified in the current study to be potentially highly suitable microhabitats for alien invasiveness and should be prioritized for monitoring and conservation actions. Moreover, the three identified species could be used as early indicators for microhabitats at risk of invasion along the environmental gradients of temperature and precipitation in arid ecosystems. This approach can be applied to other taxa and other ecosystems and can provide opportunities for formulating proactive management strategies against biological invasions.
Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP... more Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP) is crucial for biodiversity conservation and for predicting future anthropogenic impacts on ecosystems. Here, we collected Quaternary paleo-, palynological, and phylogeographical records from across the TP and applied ecological niche models (ENMs) to obtain a profound understanding of the different adaptation strategies and distributional changes in Abies trees in this unique area. We identified environmental variables affecting the different historical biogeographies of four related endemic Abies taxa and rebuilt their distribution patterns over different time periods, starting from the late Pleistocene. In addition, modeling and phylogeographic results were used to predict suitable refugia for Abies forrestii, A. forrestii var. georgei, A. fargesii var. faxoniana, and A. recurvata. We supplemented the ENMs by investigating pollen records and diversity patterns of cpDNA for them. The overall reconstructed distributions of these Abies taxa were dramatically different when the late Pleistocene was compared with the present. All Abies taxa gradually receded from the south toward the north in the last glacial maximum (LGM). The outcomes showed two well-differentiated distributions: A. fargesii var. faxoniana and A. recurvata occurred throughout the Longmen refuge, a temporary refuge for the LGM, while the other two Abies taxa were distributed throughout the Heqing refuge. Both the seasonality of precipitation and the mean temperature of the driest quarter played decisive roles in driving the distribution of A. fargesii var. faxoniana and A. recurvata,
In Egypt, monitoring and assessing the changes in natural biodiversity by the traditional site-ba... more In Egypt, monitoring and assessing the changes in natural biodiversity by the traditional site-based methods involve considerable effort and costs. Alternatively, remote sensing can be used as a promising technique to provide complete coverage of habitat, and vegetation species at a specific study area over a given period. Hence, this chapter considers the state-of-the-art of remote sensing for mapping the environmental variables at different locations in Egypt, including deserts, oases, sand dunes, saltmarshes, fish farms, reed vegetation, and agricultural lands. Moreover, the detections of land use/land cover (LULC), soil properties, spatial rainfall distribution, and surface runoff, as well as the management of flood and water resources, by geographical information systems (GIS) were demonstrated. The chapter undertakes useful information and knowledge about the Egyptian environment, giving multiple benefits to researchers, policy planners, and stakeholders. The study objectives are illustrated regarding previous articles reported in the literature.
The role of heritage sites as a shelter for biodiversity is overlooked. Eight archeological sites... more The role of heritage sites as a shelter for biodiversity is overlooked. Eight archeological sites representing different landscapes in Alexandria City were surveyed, from which 59 stands were sampled between April 2019 and March 2021. The archeological sites and the relictual landscapes are geographically dispersed and are arranged here from west to east, representing the full range of environmental variation within the study area. The selection of stands in each site was based on the area and the variability within the habitats, the physiography, and the levels of disturbance. A composite soil sample was collected from each site. Two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DECORANA) were carried out to identify the plant communities in the study area. The recorded taxa, their national geographical distribution, life forms, habitats, chorological types, and vegetation groups are listed. A total of 221 specific taxa, 172 native and 49 alien no...
The Regional Assessment Report on Biodiversity and Ecosystem Services for Africa produced by the ... more The Regional Assessment Report on Biodiversity and Ecosystem Services for Africa produced by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) provides a critical analysis of the state of knowledge regarding the importance, status, and trends of biodiversity and nature's contributions to people. The assessment analyses the direct and underlying causes for the observed changes in biodiversity and in nature's contributions to people, and the impact that these changes have on the quality of life of people. The assessment, finally, identifies a mix of governance options, policies and management practices that are currently available to reduce the loss of biodiversity and of nature's contributions to people in that region. The assessment addresses terrestrial, freshwater, and coastal biodiversity and covers current status and trends, going back in time several decades, and future projections, with a focus on the 2020-2050 period.<...
The application of species distribution modeling in deserts is a useful tool for mapping species ... more The application of species distribution modeling in deserts is a useful tool for mapping species and assessing the impact of human induced changes on individual species. Such applications are still rare, and this may be attributed to the fact that much of the arid lands and deserts around the world are located in inaccessible areas. The current study is the first to conduct spatially explicit modeling of plant species distribution in Egypt. The random forest modeling approach was applied to climatic and land-surface parameters to predict the distribution of selected important plant species in an arid landscape in the northwestern coastal desert of Egypt. The impact of changes in land use and climate on the distribution of the plant species was assessed. The results indicate that the changes in land use in the area over the last 23 years have resulted in habitat loss for all the modeled species. Projected future changes in land use reveals that all the modeled species will continue to suffer habitat loss. The projected impact of modeled climate scenarios (A1B, A2A and B2A) on the distribution of the modeled species by 2040 varied. Some of the species were projected to be adversely affected by the changes in climate, while other species are expected to benefit from these changes. The combined impact of the changes in land use and climate pose serious threats to most of the modeled species. The study found that all the species are expected to suffer loss in habitat, except Gymnocarpos decanderus. The study highlights the importance of assessing the impact of land use/climate change scenarios on other species of restricted distribution in the area and can help shape policy and mitigation efforts to protect and preserve biodiversity in desert of Egypt. : climate change scenarios, arid lands, plant species, land use change, Egypt environmental factors control the distribution of species and consequently communities (Franklin 1995; Guisan & Zimmermann 2000; Guisan & Thuiller 2005). Prediction of species distribution started early on by descriptive studies conducted by ecologists interested in understanding the relationship between patterns of species in relation to geographical settings and environmental gradients (Elith & Leathwick 2009). Later the evolution in ecology and other related fields coupled by the emergence of numerical analysis and quantitative approaches greatly influenced species distribution modeling. According to Elith & Leathwick (2009) quantitative approaches of species distribution modeling developed as a result of convergence of two lines of research trends in ecology and geography. The first line started in ecology as field-based research that studied species-habitat relationships. These studies later adopted quantitative approaches by applying statistical analysis techniques (e.g. linear multiple regression techniques), then the advanced regression techniques (e.g. Generalized Liner Models (GLMs) and boosted regression techniques) were developed to overcome limitations of the linear paradigm. The second line emerged in geography, and specifically in physical geography, through the advancement in geographic information systems and remote sensing techniques. The integration of GIS and remote sensing has allowed the development of methods for interpolation of global climate and modeling global surface elevation, in addition to provision of spectral data that were employed in species prediction models. The development of the field of species distribution modeling and mapping has been driven by the need to map vegetation patterns over large areas for resource management, conservation planning, and to predict the effects of environmental changes on vegetation distribution (Franklin 1995; Guisan & Thuiller 2005). A number of statistical and, more recently, machine-learning methods have been developed for conducting SDM over the last two decades . A review of species distribution modeling techniques and approaches used can be found in Franklin (1995), , Guisan & Thuiller (2005), Elith & Leathwick (2009. Although there are many approaches used for the species distribution modeling, no rules exist to provide guidelines on which is the best modeling approach to use (Franklin 2009). It is also likely that some approaches may be better for prediction of one species over others. This is related to many factors that include: the nature of the data used (quantity & quality); the nature of the predicator variables used; the spatial scale used (resolution and the extent); and the relevance of the environmental predicators used to the ecological characteristics of the species being predicted (
Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regi... more Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regions. Understanding driving forces affecting the potential global distribution would help in managing its current and future spread. The role of climate on the global spatial distribution of P. juliflora has been well studied, but little is known about the role of soil and human impacts as potential drivers. Here, we used maximum entropy (MaxEnt) for species distribution modelling to understand the role of climate (C), soil (S) and human impacts (H), C+S, and C+S+H in controlling the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quart...
Climate change is an important driver of biodiversity loss and extinction of endemic montane spec... more Climate change is an important driver of biodiversity loss and extinction of endemic montane species. In China, three endemic Juniperus spp. (Juniperuspingii var. pingii, J.tibetica, and J.komarovii) are threatened and subjected to the risk of extinction. This study aimed to predict the potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explai...
The eastern coastal area of the Arabian Peninsula is subject to overgrazing, agricultural activit... more The eastern coastal area of the Arabian Peninsula is subject to overgrazing, agricultural activities, oil pollution and urban encroachments. These activities cause habitat destruction and may have changed species composition. The current study aimed at assessing conservation and ethnobotanical importance of plants and how they are affected by environmental threats. The natural vegetation composition was studied and the ethnobotanical relative importance (RI) index and the species conservation index (SCI) were calculated. The results showed that native plants provide many ecological and socioeconomic services, including the provisioning of food, medicine, and energy. The native species (&gt;77%) were reported to potentially be used for more than 170 therapeutic applications and for curing various human ailments. The medicinal plants (15%) attained RI value &gt;50% reflecting high versatility and importance in local pharmacopeia. The number of threats to species showed significant positive association with SCI index and insignificant positive association with RI index. The study indicated that the current human activities may have negatively impacted provisioning of ecosystem services especially those offered by native plants. The ability of the natural ecosystems to sustainably provide services will be enhanced by adoption of land management practices that restore species and reduce pressure on native plants.
Remote Sensing Applications: Society and Environment
Abstract Human activities cause introduction of alien species to new areas, which may cause serio... more Abstract Human activities cause introduction of alien species to new areas, which may cause serious problems and threats to biodiversity and ecosystem services. Omayed biosphere reserve (OBR) at the northwestern desert of Egypt, recognized for its rich flora, has recently encountered new human-induced disturbances. The current study sought to identify alien species that might have invaded OBR as a result of such activities; and to estimate the area affected by alien species using remotely-sensed data. Field surveys of 300 sampling plots representing different habitats were conducted from spring 2011 to spring 2014, whereby occurrences of alien plant species were recorded. We evaluated the use of combined environmental and remotely-sensed data for developing predictive distribution models for 21 alien species recorded in the area using Maxent modeling technique. The inclusion spectral predictors with other environmental predictors has improved the performance of the distribution models (mean test AUC 0.88 ± 0.06) for most of the alien species. Environmental variables that contributed the most to prediction of alien species distribution included soil, elevation and slope; in addition to predictors that represented disturbance proxies such as distance from irrigation canals and distance from roads. The results revealed that more than 40% of the area is predicted to be infested by at least one alien species. Results also manifest the merit of incorporating remotely-sensed data in prediction of alien species distribution, which hold promise for development of proactive management approaches to identify and control areas of high infestation of alien species and prevent further spread of invasive plants.
Robust classification approaches are required for accurate classification of complex land-use/lan... more Robust classification approaches are required for accurate classification of complex land-use/land-cover categories of desert landscapes using remotely sensed data. Machine-learning ensemble classifiers have proved to be powerful for the classification of remotely sensed data. However, they have not been evaluated for classifying land-cover categories in desert regions. In this study, the performance of two machine-learning ensemble classifiers – random forests (RF) and boosted artificial neural networks – is explored in the context of classification of land use/land cover of desert landscapes. The evaluation is based on the accuracy of classification of remotely sensed data, with and without integration of ancillary data. Landsat-5 Thematic Mapper data captured for a desert landscape in the north-western coastal desert of Egypt are used with ancillary variables derived from a digital terrain model to classify 13 different land-use/land-cover categories. Results show that the two ensemble methods produce accurate land-cover classifications, with and without integrating spectral data with ancillary data. In general, the overall accuracy exceeded 85% and the kappa coefficient (κ) attained values over 0.83. The integration of ancillary data improved the performance of the boosted artificial neural networks by approximately 5% and the random forests by 9%. The latter showed overall higher accuracy; however, boosted artificial neural networks showed better generalization ability and lower overfitting tendencies. The results reveal the merit of applying ensemble methods to integrated spectral and ancillary data of similar desert landscapes for achieving high classification accuracies.
Quantitative approaches used for detecting biodiversity ‘hotspots’ depend mostly on species occur... more Quantitative approaches used for detecting biodiversity ‘hotspots’ depend mostly on species occurrence data. This approach has been criticized for not recognizing all aspects of species importance. In this study, we used information on plant species to estimate a species conservation importance (SCI) and compare sites’ conservation value (SCV) at the landscape level with regard to plant species. The SCI index assesses vascular plant significance based on inclusion of many criteria accounting to various aspects of species importance. The SCI index was calculated for the 405 plant species recorded in a northwestern coastal desert landscape, and two protected areas in Egypt. The Comparison revealed that despite having the highest number of species, the northwestern coastal desert landscape ranked third to the other protected areas based on SCV. For highlighting ‘hotspots’ of conservation priority regarding vascular plants in the northwestern coastal desert landscape, the Getis-Ord Gi* hotspot geostatistical analyses were applied to the per-plot number of species, maximum SCI, average SCI (ACI), and SCV values of 827 sampled plots. The results revealed the occurrence of significant hotspots for plant conservation at the south of the landscape. The application of Getis-Ord Gi* geostatistical analysis to conservation indices promises to be a useful tool in identification of hotspots at the landscape level. The approach used in the current study will help in comparing and ranking regions according plant species conservation priorities. It can also be used for guiding site selection efforts regarding plant species conservation particularly in similar ecosystems.
ABSTRACT Abstract Detecting land-use change has become of concern to environmentalists, conservat... more ABSTRACT Abstract Detecting land-use change has become of concern to environmentalists, conservationists and land use planners due to its impact on natural ecosystems. We studied land use/land cover (LULC) changes in part of the northwestern desert of Egypt and used the Markov-CA integrated approach to predict future changes. We mapped the LULC distribution of the desert landscape for 1988, 1999, and 2011. Landsat Thematic Mapper 5 data and ancillary data were classified using the random forests approach. The technique produced LULC maps with an overall accuracy of more than 90%. Analysis of LULC classes from the three dates revealed that the study area was subjected to three different stages of modification, each dominated by different land uses. The use of a spatially explicit land use change modeling approach, such as Markov-CA approach, provides ways for projecting different future scenarios. Markov-CA was used to predict land use change in 2011 and project changes in 2023 by extrapolating current trends. The technique was successful in predicting LULC distribution in 2011 and the results were comparable to the actual LULC for 2011. The projected LULC for 2023 revealed more urbanization of the landscape with potential expansion in the croplands westward and northward, an increase in quarries, and growth in residential centers. The outcomes can help management activities directed toward protection of wildlife in the area. The study can also be used as a guide to other studies aiming at projecting changes in arid areas experiencing similar land use changes.
Panicum turgidum is one of the most drought resistant plants in the Egyptian desert. Five habitat... more Panicum turgidum is one of the most drought resistant plants in the Egyptian desert. Five habitat types were selected for the study: sand dunes (North Sinai and in Wady El-Natrun), gravel desert, coastal plain, and water runnels of a wadi bed (South Sinai and Eastern Desert). About 47.4% of the studied sites were subjected to high grazing pressure, 26.3% to moderate grazing pressure; the remaining 26.3% were subjected to low grazing pressure. Concentration of the nutrients (K, Na, Ca, P and Ca/P ratio) in the grazeable parts of P. turgidum populations exhibited insignificant variability between habitats and phytogeographical regions. Meanwhile, concentration of potassium showed significant variability between the phytogeographical regions. Ca/P ratio of the grazeable parts of P. turgidum was significantly related to the soil silt and organic matter content. The percentage of crude protein was higher than the minimum required for the maintenance of the grazing animals, i.e. P. turgidum has a good or excellent forage quality. Due to its high nutritive value and ease of cultivation, P. turgidum grains could be considered as a potential crop, which may serve as a supplementary food to the common cereals. It worth noting that the variation in the nutritive values among the cultivated populations was insignificant as all the cultivated populations had a high nutritive value, indicating the effect of edaphic factors on the wild population nutritive value which was proved also from the correlation between the edaphic factors and nutritive variable.
Simple Summary Intra-city railway areas can play a role in enhancing the diversity and dynamics o... more Simple Summary Intra-city railway areas can play a role in enhancing the diversity and dynamics of urban flora. The current study sheds the light on the role that overlooked railway habitats can provide in the conservation of biodiversity through surveying the floristic composition and diversity along intra-city railway and tram tracks in Alexandria. The plant communities were identified using multivariate analysis techniques. Spontaneous flora in intra-city railway areas represent distinct adaptations to unique urban–industrial ecosystems with different levels of anthropogenic disturbance. Despite the high level of disturbance, native species dominated the investigated habitats, including rare and endemic species. The study emphasizes the role that these ruderal habitats provide as valuable refuge areas for rare and endangered species worthy of proper management and conservation action. Abstract Intra-city railway areas are deemed large greenspaces and are believed to be key in enh...
Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP... more Understanding the factors driving the Quaternary distribution of Abies in the Tibetan Plateau (TP) is crucial for biodiversity conservation and for predicting future anthropogenic impacts on ecosystems. Here, we collected Quaternary paleo-, palynological, and phylogeographical records from across the TP and applied ecological niche models (ENMs) to obtain a profound understanding of the different adaptation strategies and distributional changes in Abies trees in this unique area. We identified environmental variables affecting the different historical biogeographies of four related endemic Abies taxa and rebuilt their distribution patterns over different time periods, starting from the late Pleistocene. In addition, modeling and phylogeographic results were used to predict suitable refugia for Abies forrestii, A. forrestii var. georgei, A. fargesii var. faxoniana, and A. recurvata. We supplemented the ENMs by investigating pollen records and diversity patterns of cpDNA for them. The overall reconstructed distributions of these Abies taxa were dramatically different when the late Pleistocene was compared with the present. All Abies taxa gradually receded from the south toward the north in the last glacial maximum (LGM). The outcomes showed two well-differentiated distributions: A. fargesii var. faxoniana and A. recurvata occurred throughout the Longmen refuge, a temporary refuge for the LGM, while the other two Abies taxa were distributed throughout the Heqing refuge. Both the seasonality of precipitation and the mean temperature of the driest quarter played decisive roles in driving the distribution of A. fargesii var. faxoniana and A. recurvata, respectively; the annual temperature range was also a key variable that explained the distribution patterns of the other two Abies taxa. Different adaptation strategies of trees may thus explain the differing patterns of distribution over time at the TP revealed here for endemic Abies taxa.
Climate change is an important driver of biodiversity loss and extinction of endemic montane spec... more Climate change is an important driver of biodiversity loss and extinction of endemic montane species. In China, three endemic Juniperus spp. (Juniperus pingii var. pingii, J. tibetica, and J. komarovii) are threatened and subjected to the risk of extinction. This study aimed to predict the potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explaining the potential distribution of these three Juniperus species; they contribute by 16–56.1% and 20.4–38.3%, respectively. Accounting for the use of different thresholds provides a balanced approach for species distribution models’ applications in conservation assessment when the goal is to assess potential climatic suitability in new geographical areas. Therefore, south Sichuan and north Yunnan could be considered important priority conservation areas for in situ conservation and search for unknown populations of these three Juniperus species.
Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regi... more Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regions. Understanding driving forces affecting the potential global distribution would help in managing its current and future spread. The role of climate on the global spatial distribution of P. juliflora has been well studied, but little is known about the role of soil and human impacts as potential drivers. Here, we used maximum entropy (MaxEnt) for species distribution modelling to understand the role of climate (C), soil (S) and human impacts (H), C+S, and C+S+H in controlling the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest risk of invasion than other moist biomes.
Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regi... more Prosopis juliflora is one of the most problematic invasive trees in tropical and subtropical regions. Understanding driving forces affecting the potential global distribution would help in managing its current and future spread. The role of climate on the global spatial distribution of P. juliflora has been well studied, but little is known about the role of soil and human impacts as potential drivers. Here, we used maximum entropy (MaxEnt) for species distribution modelling to understand the role of climate (C), soil (S) and human impacts (H), C+S, and C+S+H in controlling the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest risk of invasion than other moist biomes.
In Egypt, monitoring and assessing the changes in natural biodiversity by the traditional site-ba... more In Egypt, monitoring and assessing the changes in natural biodiversity by the traditional site-based methods involve considerable effort and costs. Alternatively, remote sensing can be used as a promising technique to provide complete coverage of habitat, and vegetation species at a specific study area over a given period. Hence, this chapter considers the state-of-the-art of remote sensing for mapping the environmental variables at different locations in Egypt, including deserts, oases, sand dunes, saltmarshes, fish farms, reed vegetation, and agricultural lands. Moreover, the detections of land use/land cover (LULC), soil properties, spatial rainfall distribution, and surface runoff, as well as the management of flood and water resources, by geographical information systems (GIS) were demonstrated. The chapter undertakes useful information and knowledge about the Egyptian environment, giving multiple benefits to researchers, policy planners, and stakeholders. The study objectives are illustrated regarding previous articles reported in the literature. Keywords Ecological monitoring • Egyptian environment • Habitat detection • Landsat satellite • Remote sensing 6.1 Introduction Recently, in Egypt, urbanization, anthropogenic activities, and exponential population growth have resulted in severe reductions in water bodies and agricultural lands (Halmy 2019). Remotely sensed data, including satellite images, and aerial photos
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Papers by Marwa Waseem
and distributional changes in Abies trees in this unique area. We identified environmental variables affecting the different historical biogeographies of four related endemic Abies taxa and rebuilt their distribution patterns over different time periods, starting from the late Pleistocene. In addition, modeling and phylogeographic results were used to predict suitable refugia for Abies forrestii, A. forrestii var. georgei, A. fargesii var. faxoniana, and A. recurvata. We supplemented the ENMs by investigating
pollen records and diversity patterns of cpDNA for them. The overall reconstructed distributions of these Abies taxa were dramatically different when the late Pleistocene was compared with the present. All Abies taxa gradually receded from the south toward the north in the last glacial maximum (LGM). The outcomes showed two well-differentiated distributions: A. fargesii var. faxoniana and A. recurvata occurred
throughout the Longmen refuge, a temporary refuge for the LGM, while the
other two Abies taxa were distributed throughout the Heqing refuge. Both the seasonality of precipitation and the mean temperature of the driest quarter played decisive roles in driving the distribution of A. fargesii var. faxoniana and A. recurvata, respectively; the annual temperature range was also a key variable that explained the distribution patterns of the other two Abies taxa. Different adaptation strategies of trees may thus explain the differing patterns of distribution over time at the TP revealed here for endemic Abies taxa.
potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explaining the potential distribution of these three Juniperus species; they contribute by 16–56.1% and 20.4–38.3%, respectively. Accounting for the use of different thresholds provides a balanced approach for species distribution models’ applications in conservation assessment when the goal is to assess potential climatic suitability in new geographical areas. Therefore, south Sichuan and north Yunnan could be considered important priority conservation areas for in situ conservation and search for unknown populations of these three Juniperus species.
the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest
risk of invasion than other moist biomes.
the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest
risk of invasion than other moist biomes.
and distributional changes in Abies trees in this unique area. We identified environmental variables affecting the different historical biogeographies of four related endemic Abies taxa and rebuilt their distribution patterns over different time periods, starting from the late Pleistocene. In addition, modeling and phylogeographic results were used to predict suitable refugia for Abies forrestii, A. forrestii var. georgei, A. fargesii var. faxoniana, and A. recurvata. We supplemented the ENMs by investigating
pollen records and diversity patterns of cpDNA for them. The overall reconstructed distributions of these Abies taxa were dramatically different when the late Pleistocene was compared with the present. All Abies taxa gradually receded from the south toward the north in the last glacial maximum (LGM). The outcomes showed two well-differentiated distributions: A. fargesii var. faxoniana and A. recurvata occurred
throughout the Longmen refuge, a temporary refuge for the LGM, while the
other two Abies taxa were distributed throughout the Heqing refuge. Both the seasonality of precipitation and the mean temperature of the driest quarter played decisive roles in driving the distribution of A. fargesii var. faxoniana and A. recurvata, respectively; the annual temperature range was also a key variable that explained the distribution patterns of the other two Abies taxa. Different adaptation strategies of trees may thus explain the differing patterns of distribution over time at the TP revealed here for endemic Abies taxa.
potential distribution of these three Juniperus species under climate change and dispersal scenarios, to identify critical drivers explaining their potential distributions, to assess the extinction risk by estimating the loss percentage in their area of occupancy (AOO), and to identify priority areas for their conservation in China. We used ensemble modeling to evaluate the impact of climate change and project AOO. Our results revealed that the projected AOOs followed a similar trend in the three Juniperus species, which predicted an entire loss of their suitable habitats under both climate and dispersal scenarios. Temperature annual range and isothermality were the most critical key variables explaining the potential distribution of these three Juniperus species; they contribute by 16–56.1% and 20.4–38.3%, respectively. Accounting for the use of different thresholds provides a balanced approach for species distribution models’ applications in conservation assessment when the goal is to assess potential climatic suitability in new geographical areas. Therefore, south Sichuan and north Yunnan could be considered important priority conservation areas for in situ conservation and search for unknown populations of these three Juniperus species.
the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest
risk of invasion than other moist biomes.
the potential invasion range of P. juliflora, and to project its global potential invasive risk. We defined the top threatened global biomes, as predicted by the best-selected model. The incorporation of the edaphic factors improved the model performance and enhanced the accuracy of the outcome. Our findings revealed that the potential invasion risk increases with increases in mean temperature of the driest quarter (Bio9), soil alkalinity and clay fractions. Arid and semi-arid lands are at the highest
risk of invasion than other moist biomes.