The Experts below are selected from a list of 74280 Experts worldwide ranked by ideXlab platform
Huabin Zhang - One of the best experts on this subject based on the ideXlab platform.
-
historical population decline and Habitat Loss in a critically endangered species the chinese alligator alligator sinensis
2019Co-Authors: Huan Wang, Shulong Duan, Jihui Zhang, Huabin Zhang, Baowei Zhang, Mingsheng Wang, Xiaobing WuAbstract:Abstract Habitat Loss and degradation are among the leading causes of local extinctions, so it is crucially important to preserve and restore the remaining critical Habitat increasingly critical to conserve biodiversity. However, mechanisms driving species extinction often begin with Habitat Loss and seldom are well understood, which is greatly limits our ability to mitigate their impacts. The Chinese Alligator ( Alligator sinensis ) is a critically endangered crocodilian, which is narrowly distributed in very small six regions of Anhui province, China. In the present study, we used 9 nuclear microsatellite loci genotyped across the taxon's distribution area to investigate genetic variation and population demography in A. sinensis . The Chinese Alligator showed unusually low levels of genetic diversity ( N a, 5.44; N e, 1.97; H e, 0.47) based on 793 individuals. Msvar analyses found recent signals of population decline reflecting a bottleneck (an approximately 9-fold decrease) about 25,000 years ago. Ecological niche modelling has shown that the Habitat area has declined (about 8–15 fold) for A. sinensis when compared with that under different historical climatic conditions. Our results indicated that population decline and Habitat Loss in critically endangered Chinese Alligators may have acted as intrinsic and extrinsic factors that have impacted the current status of A. sinensis . In addition, these two unfavorable factors may have also directly contributed to a reduction in the genetic diversity of A. sinensis .
-
historical population decline and Habitat Loss in a critically endangered species the chinese alligator alligator sinensis
2019Co-Authors: Shulong Duan, Jihui Zhang, Mingsheng Wang, Huan Wang, Peng Yan, Ruiqing Cai, Tao Pan, Izaz Ali, Huabin ZhangAbstract:Abstract Habitat Loss and degradation are among the leading causes of local extinctions, so it is crucially important to preserve and restore the remaining critical Habitat increasingly critical to conserve biodiversity. However, mechanisms driving species extinction often begin with Habitat Loss and seldom are well understood, which is greatly limits our ability to mitigate their impacts. The Chinese Alligator (Alligator sinensis) is a critically endangered crocodilian, which is narrowly distributed in very small six regions of Anhui province, China. In the present study, we used 9 nuclear microsatellite loci genotyped across the taxon's distribution area to investigate genetic variation and population demography in A. sinensis. The Chinese Alligator showed unusually low levels of genetic diversity (Na, 5.44; Ne, 1.97; He, 0.47) based on 793 individuals. Msvar analyses found recent signals of population decline reflecting a bottleneck (an approximately 9-fold decrease) about 25,000 years ago. Ecological niche modelling indicated that the Habitat area has declined (about 8–15 fold) for A. sinensis when compared with that under different historical climatic conditions. Our results indicated that population decline and Habitat Loss in critically endangered Chinese Alligators may have acted as intrinsic and extrinsic factors that have impacted the current status of A. sinensis. In addition, these two unfavorable factors may have also directly contributed to a reduction in the genetic diversity of A. sinensis.
Tao Pan - One of the best experts on this subject based on the ideXlab platform.
-
historical population decline and Habitat Loss in a critically endangered species the chinese alligator alligator sinensis
2019Co-Authors: Shulong Duan, Jihui Zhang, Mingsheng Wang, Huan Wang, Peng Yan, Ruiqing Cai, Tao Pan, Izaz Ali, Huabin ZhangAbstract:Abstract Habitat Loss and degradation are among the leading causes of local extinctions, so it is crucially important to preserve and restore the remaining critical Habitat increasingly critical to conserve biodiversity. However, mechanisms driving species extinction often begin with Habitat Loss and seldom are well understood, which is greatly limits our ability to mitigate their impacts. The Chinese Alligator (Alligator sinensis) is a critically endangered crocodilian, which is narrowly distributed in very small six regions of Anhui province, China. In the present study, we used 9 nuclear microsatellite loci genotyped across the taxon's distribution area to investigate genetic variation and population demography in A. sinensis. The Chinese Alligator showed unusually low levels of genetic diversity (Na, 5.44; Ne, 1.97; He, 0.47) based on 793 individuals. Msvar analyses found recent signals of population decline reflecting a bottleneck (an approximately 9-fold decrease) about 25,000 years ago. Ecological niche modelling indicated that the Habitat area has declined (about 8–15 fold) for A. sinensis when compared with that under different historical climatic conditions. Our results indicated that population decline and Habitat Loss in critically endangered Chinese Alligators may have acted as intrinsic and extrinsic factors that have impacted the current status of A. sinensis. In addition, these two unfavorable factors may have also directly contributed to a reduction in the genetic diversity of A. sinensis.
Anna Traveset - One of the best experts on this subject based on the ideXlab platform.
-
Impact of Habitat Loss on the diversity and structure of ecological networks between oxyurid nematodes and spur-thighed tortoises (Testudo graeca L.).
2019Co-Authors: Julieta Benítez-malvido, Andrés Giménez, Roberto C. Rodríguez-caro, Eva Graciá, Rocío Ruiz De Ybáñez, Héctor Hugo Siliceo-cantero, Anna TravesetAbstract:Habitat Loss and fragmentation are recognized as affecting the nature of biotic interactions, although we still know little about such changes for reptilian herbivores and their hindgut nematodes, in which endosymbiont interactions could range from mutualistic to commensal and parasitic. We investigated the potential cost and benefit of endosymbiont interactions between the spur-thighed tortoise (Testudo graeca L.) and adult oxyurid nematodes (Pharyngodonidae order Oxyurida) in scrublands of southern Spain. For this, we assessed the association between richness and abundance of oxyurid species with tortoises' growth rates and body traits (weight and carapace length) across levels of Habitat Loss (low, intermediate and high). Furthermore, by using an intrapopulation ecological network approach, we evaluated the structure and diversity of tortoise-oxyurid interactions by focusing on oxyurid species infesting individual tortoises with different body traits and growth rates across Habitats. Overall, tortoise body traits were not related to oxyurid infestation across Habitats. Oxyurid richness and abundance however, showed contrasting relationships with growth rates across levels of Habitat Loss. At low Habitat Loss, oxyurid infestation was positively associated with growth rates (suggesting a mutualistic oxyurid-tortoise relationship), but the association became negative at high Habitat Loss (suggesting a parasitic relationship). Furthermore, no relationship was observed when Habitat Loss was intermediate (suggesting a commensal relationship). The network analysis showed that the oxyurid community was not randomly assembled but significantly nested, revealing a structured pattern for all levels of Habitat Loss. The diversity of interactions was lowest at low Habitat Loss. The intermediate level, however, showed the greatest specialization, which indicates that individuals were infested by fewer oxyurids in this landscape, whereas at high Habitat Loss individuals were the most generalized hosts. Related to the latter, connectance was greatest at high Habitat Loss, reflecting a more uniform spread of interactions among oxyurid species. At an individual level, heavier and larger tortoises tended to show a greater number of oxyurid species interactions. We conclude that there is an association between Habitat Loss and the tortoise-oxyurid interaction. Although we cannot infer causality in their association, we hypothesize that such oxyurids could have negative, neutral and positive consequences for tortoise growth rates. Ecological network analysis can help in the understanding of the nature of such changes in tortoise-oxyurid interactions by showing how generalized or specialized such interactions are under different environmental conditions and how vulnerable endosymbiont interactions might be to further Habitat Loss.
Traveset Anna - One of the best experts on this subject based on the ideXlab platform.
-
Impact of Habitat Loss on the diversity and structure of ecological networks between oxyurid nematodes and spur-thighed tortoises (Testudo graeca L.)
2020Co-Authors: Benítez-malvido Julieta, Giménez Andrés, Graciá Eva, Rodríguez-caro, Roberto Carlos, Ruiz De Ybáñez, Rocío, Siliceo-cantero, Héctor Hugo, Traveset AnnaAbstract:Habitat Loss and fragmentation are recognized as affecting the nature of biotic interactions, although we still know little about such changes for reptilian herbivores and their hindgut nematodes, in which endosymbiont interactions could range from mutualistic to commensal and parasitic. We investigated the potential cost and benefit of endosymbiont interactions between the spur-thighed tortoise (Testudo graeca L.) and adult oxyurid nematodes (Pharyngodonidae order Oxyurida) in scrublands of southern Spain. For this, we assessed the association between richness and abundance of oxyurid species with tortoises’ growth rates and body traits (weight and carapace length) across levels of Habitat Loss (low, intermediate and high). Furthermore, by using an intrapopulation ecological network approach, we evaluated the structure and diversity of tortoise–oxyurid interactions by focusing on oxyurid species infesting individual tortoises with different body traits and growth rates across Habitats. Overall, tortoise body traits were not related to oxyurid infestation across Habitats. Oxyurid richness and abundance however, showed contrasting relationships with growth rates across levels of Habitat Loss. At low Habitat Loss, oxyurid infestation was positively associated with growth rates (suggesting a mutualistic oxyurid–tortoise relationship), but the association became negative at high Habitat Loss (suggesting a parasitic relationship). Furthermore, no relationship was observed when Habitat Loss was intermediate (suggesting a commensal relationship). The network analysis showed that the oxyurid community was not randomly assembled but significantly nested, revealing a structured pattern for all levels of Habitat Loss. The diversity of interactions was lowest at low Habitat Loss. The intermediate level, however, showed the greatest specialization, which indicates that individuals were infested by fewer oxyurids in this landscape, whereas at high Habitat Loss individuals were the most generalized hosts. Related to the latter, connectance was greatest at high Habitat Loss, reflecting a more uniform spread of interactions among oxyurid species. At an individual level, heavier and larger tortoises tended to show a greater number of oxyurid species interactions. We conclude that there is an association between Habitat Loss and the tortoise–oxyurid interaction. Although we cannot infer causality in their association, we hypothesize that such oxyurids could have negative, neutral and positive consequences for tortoise growth rates. Ecological network analysis can help in the understanding of the nature of such changes in tortoise–oxyurid interactions by showing how generalized or specialized such interactions are under different environmental conditions and how vulnerable endosymbiont interactions might be to further Habitat Loss.The Dirección General de Gestión del Medio Natural de la Junta de Andalucía (SGB/FOA/AFR) and the Delegación General de Medio Natural de la Comunidad Autónoma de la Región de Murcia (AUT/ET/UND/48/2010) granted permission to sample the tortoises and nematodes
Huan Wang - One of the best experts on this subject based on the ideXlab platform.
-
historical population decline and Habitat Loss in a critically endangered species the chinese alligator alligator sinensis
2019Co-Authors: Huan Wang, Shulong Duan, Jihui Zhang, Huabin Zhang, Baowei Zhang, Mingsheng Wang, Xiaobing WuAbstract:Abstract Habitat Loss and degradation are among the leading causes of local extinctions, so it is crucially important to preserve and restore the remaining critical Habitat increasingly critical to conserve biodiversity. However, mechanisms driving species extinction often begin with Habitat Loss and seldom are well understood, which is greatly limits our ability to mitigate their impacts. The Chinese Alligator ( Alligator sinensis ) is a critically endangered crocodilian, which is narrowly distributed in very small six regions of Anhui province, China. In the present study, we used 9 nuclear microsatellite loci genotyped across the taxon's distribution area to investigate genetic variation and population demography in A. sinensis . The Chinese Alligator showed unusually low levels of genetic diversity ( N a, 5.44; N e, 1.97; H e, 0.47) based on 793 individuals. Msvar analyses found recent signals of population decline reflecting a bottleneck (an approximately 9-fold decrease) about 25,000 years ago. Ecological niche modelling has shown that the Habitat area has declined (about 8–15 fold) for A. sinensis when compared with that under different historical climatic conditions. Our results indicated that population decline and Habitat Loss in critically endangered Chinese Alligators may have acted as intrinsic and extrinsic factors that have impacted the current status of A. sinensis . In addition, these two unfavorable factors may have also directly contributed to a reduction in the genetic diversity of A. sinensis .
-
historical population decline and Habitat Loss in a critically endangered species the chinese alligator alligator sinensis
2019Co-Authors: Shulong Duan, Jihui Zhang, Mingsheng Wang, Huan Wang, Peng Yan, Ruiqing Cai, Tao Pan, Izaz Ali, Huabin ZhangAbstract:Abstract Habitat Loss and degradation are among the leading causes of local extinctions, so it is crucially important to preserve and restore the remaining critical Habitat increasingly critical to conserve biodiversity. However, mechanisms driving species extinction often begin with Habitat Loss and seldom are well understood, which is greatly limits our ability to mitigate their impacts. The Chinese Alligator (Alligator sinensis) is a critically endangered crocodilian, which is narrowly distributed in very small six regions of Anhui province, China. In the present study, we used 9 nuclear microsatellite loci genotyped across the taxon's distribution area to investigate genetic variation and population demography in A. sinensis. The Chinese Alligator showed unusually low levels of genetic diversity (Na, 5.44; Ne, 1.97; He, 0.47) based on 793 individuals. Msvar analyses found recent signals of population decline reflecting a bottleneck (an approximately 9-fold decrease) about 25,000 years ago. Ecological niche modelling indicated that the Habitat area has declined (about 8–15 fold) for A. sinensis when compared with that under different historical climatic conditions. Our results indicated that population decline and Habitat Loss in critically endangered Chinese Alligators may have acted as intrinsic and extrinsic factors that have impacted the current status of A. sinensis. In addition, these two unfavorable factors may have also directly contributed to a reduction in the genetic diversity of A. sinensis.
