Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communit...Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communities on a small scale. To evaluate the relative roles of biotic interactions and environmental and spatial processes in a soil collembolan community, a field experiment was carried out on a small scale(50 m) in the farmland ecosystem of the Sanjiang Plain, Northeast China. In August and October, 2011, we took 100 samples each month in a 50 m × 50 m plot using a spatially delimited sampling design. Variation partitioning was used to quantify the relative contributions of the spatial and environmental variables. A null model was selected to test for the non-randomness pattern of species co-occurrence and body size in assemblages of collembolans and to test whether the pattern observed was the result of environmental or biotic processes that structured the community on a small scale. The results showed that large variance was accounted for by spatial variables(18.99% in August and 21.83% in October, both were significant). There were relatively lower effects of environmental variation(3.56% in August and 1.45% in October, neither was significant), while the soil water content, soil p H and soybean height explained a significant portion of the variance that was observed in the spatial pattern of the collembolan community. Furthermore, the null model revealed more co-occurrence than expected by chance, suggesting that collembolan communities had a non-random co-occurrence pattern in both August and October. Additionally, environmental niche overlap and the body size ratio of co-occurrence showed that interspecific competition was not influential in collembolan community structuring. Considering all of the results together, the contributions of spatial and environmental processes were stronger than biotic interactions in the small-scale structuring of a soil collembolan community.展开更多
A total of 900 soil samples were collected from five habitats,including primary coniferous broad-leaved mixed forests,secondary coniferous broad-leaved mixed forests,secondary broad-leaved forests,secondary shrub fore...A total of 900 soil samples were collected from five habitats,including primary coniferous broad-leaved mixed forests,secondary coniferous broad-leaved mixed forests,secondary broad-leaved forests,secondary shrub forests,and cutover lands in spring,summer,and autumn to quantify responses of soil Collembolans(springtails)to the restoration of vegetation of temperate coniferous and broad-leaved mixed forests.The results reveal that the taxonomic composition of Collembolans varied in the different stages of vegetation restoration.Seasonal variations were in regard to their abundance and richness.High similarities existed in Collembola communities at different stages of vegetation restoration,and distribution patterns of Collembola taxa displayed an evenness throughout all habitats.Soil Collembolans tended to gather on litter layers and soil surface;the highest abundance was found in the upper 5 cm soil layer during the initial stages of vegetation recovery.Tomocerus,Proisotoma,and Folsomia genera responded positively to the restoration of vegetation.However,responses of Ceratophysella and Parisotoma genera were negative.In addition,the Onychiuridae family did not respond to the vegetation restoration process.It was concluded that restoration of vegetative cover can increase the abundance of soil Collembolans,but different genera respond differently.展开更多
The unique gut habitat led to a core intestinal micro-biome in diverse soil ecosystems.The collembolan guts may help eliminate soil pathogens.Host-selection carried more weight on community assembly of gut microbiome....The unique gut habitat led to a core intestinal micro-biome in diverse soil ecosystems.The collembolan guts may help eliminate soil pathogens.Host-selection carried more weight on community assembly of gut microbiome.Soil invertebrates are widely distributed in the ecosystem and are essential for soil ecological processes.Inverte-brate gut microbiome plays an important role in host health and has been considered as a hidden microbial repository.However,little is known about how gut microbiome in soil invertebrates respond to diverse soil ecosystems.Based on a laboratory microcosm experiment,we characterized the assembling of microbiome of soil collembolans(Folsomia candida)from six representative regions of the soil ecosystem which they inhabit.Results showed that collembolan gut microbial communities differed significantly from their surrounding soil microbial communities.A dominant core gut microbiome was identified in gut habitat.Community analyses indicated that deterministic process dominated in the community assembly of collembolan gut microbiome.The results further demonstrate a dominant contribution of host selection in shaping gut microbiome.It is also worthy to mention that pathogens,such as common agricultural phytopathogenic fungi Fusarium,were involved in core microbiome,indicating that collembolans could act as vectors of pathogens.Our results unravelled the existence of gut core microbiome of collembolans in soil ecosystems and provided new insights for under-standing the crucial role of gut microbiome of soil fauna in maintaining microbial biodiversity and stability of soil ecosystems.展开更多
Laboratory studies evaluated the sensitivity of Sinella curviseta Brook （Collembola： Entomobryidae） to selected heavy metals （Cu, Pb and Zn）. Survival, reproduction and growth of S. curviseta were determined in a...Laboratory studies evaluated the sensitivity of Sinella curviseta Brook （Collembola： Entomobryidae） to selected heavy metals （Cu, Pb and Zn）. Survival, reproduction and growth of S. curviseta were determined in a 4-week exposure test in an agricultural soil amended with metals to concentrations of 100, 200, 400, 800, 1 600 and 3 200 mg/kg. Results showed reduction in adult survival and reproductive failure at the highest concentrations （3 200 mg/kg） of Cu and Zn. EC50reproduction values for Cu and Zn were approximately 442 and 2 760 mg/kg, respectively. Application of Pb at all levels resulted in large numbers of progeny and no significant mortality compared to controls. Adult growth rate decreased for all metal treatments compared to the controls, suggesting that metals affect S. curviseta metabolism and result in slower growth. We showed that reproduction is a slightly more sensitive parameter than growth. Since a growth test needs fewer juveniles and takes less time than a reproduction test, we conclude that the two parameters are complementary and could be used for a better ecotoxicological evaluation of contaminant levels. However, relative growth and reproduction sensitivities should be tested with more chemicals before a growth test is accepted as a faster sublethal test than a reproduction test.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41101049,41471037,41371072,41430857)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2015054)+1 种基金Distinguished Young Scholar of Harbin Normal University(No.KGB201204)Excellent Youth Scholars of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.DLSYQ13003)
文摘Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communities on a small scale. To evaluate the relative roles of biotic interactions and environmental and spatial processes in a soil collembolan community, a field experiment was carried out on a small scale(50 m) in the farmland ecosystem of the Sanjiang Plain, Northeast China. In August and October, 2011, we took 100 samples each month in a 50 m × 50 m plot using a spatially delimited sampling design. Variation partitioning was used to quantify the relative contributions of the spatial and environmental variables. A null model was selected to test for the non-randomness pattern of species co-occurrence and body size in assemblages of collembolans and to test whether the pattern observed was the result of environmental or biotic processes that structured the community on a small scale. The results showed that large variance was accounted for by spatial variables(18.99% in August and 21.83% in October, both were significant). There were relatively lower effects of environmental variation(3.56% in August and 1.45% in October, neither was significant), while the soil water content, soil p H and soybean height explained a significant portion of the variance that was observed in the spatial pattern of the collembolan community. Furthermore, the null model revealed more co-occurrence than expected by chance, suggesting that collembolan communities had a non-random co-occurrence pattern in both August and October. Additionally, environmental niche overlap and the body size ratio of co-occurrence showed that interspecific competition was not influential in collembolan community structuring. Considering all of the results together, the contributions of spatial and environmental processes were stronger than biotic interactions in the small-scale structuring of a soil collembolan community.
基金We express our sincere thanks to Dr.Ernest Bernard(University of Tennessee,Knoxville,USA)for his kind help.At the same time,we would like to thank Dr.Xiaoqiang Li,Dr.Zhenghai Wang,Huiying Han,Hongyue Li,Wenli Xue,Yumei Guo,and Xinchang Kou for their help with field work and laboratory analyses。
文摘A total of 900 soil samples were collected from five habitats,including primary coniferous broad-leaved mixed forests,secondary coniferous broad-leaved mixed forests,secondary broad-leaved forests,secondary shrub forests,and cutover lands in spring,summer,and autumn to quantify responses of soil Collembolans(springtails)to the restoration of vegetation of temperate coniferous and broad-leaved mixed forests.The results reveal that the taxonomic composition of Collembolans varied in the different stages of vegetation restoration.Seasonal variations were in regard to their abundance and richness.High similarities existed in Collembola communities at different stages of vegetation restoration,and distribution patterns of Collembola taxa displayed an evenness throughout all habitats.Soil Collembolans tended to gather on litter layers and soil surface;the highest abundance was found in the upper 5 cm soil layer during the initial stages of vegetation recovery.Tomocerus,Proisotoma,and Folsomia genera responded positively to the restoration of vegetation.However,responses of Ceratophysella and Parisotoma genera were negative.In addition,the Onychiuridae family did not respond to the vegetation restoration process.It was concluded that restoration of vegetative cover can increase the abundance of soil Collembolans,but different genera respond differently.
基金supported by the National Natural Science Foundation of China(No.42277102).
文摘The unique gut habitat led to a core intestinal micro-biome in diverse soil ecosystems.The collembolan guts may help eliminate soil pathogens.Host-selection carried more weight on community assembly of gut microbiome.Soil invertebrates are widely distributed in the ecosystem and are essential for soil ecological processes.Inverte-brate gut microbiome plays an important role in host health and has been considered as a hidden microbial repository.However,little is known about how gut microbiome in soil invertebrates respond to diverse soil ecosystems.Based on a laboratory microcosm experiment,we characterized the assembling of microbiome of soil collembolans(Folsomia candida)from six representative regions of the soil ecosystem which they inhabit.Results showed that collembolan gut microbial communities differed significantly from their surrounding soil microbial communities.A dominant core gut microbiome was identified in gut habitat.Community analyses indicated that deterministic process dominated in the community assembly of collembolan gut microbiome.The results further demonstrate a dominant contribution of host selection in shaping gut microbiome.It is also worthy to mention that pathogens,such as common agricultural phytopathogenic fungi Fusarium,were involved in core microbiome,indicating that collembolans could act as vectors of pathogens.Our results unravelled the existence of gut core microbiome of collembolans in soil ecosystems and provided new insights for under-standing the crucial role of gut microbiome of soil fauna in maintaining microbial biodiversity and stability of soil ecosystems.
基金Acknowledgments This work was supported by grants from the National Natural Science Foundation of China （Nos. 40671105 and 40432005）.
文摘Laboratory studies evaluated the sensitivity of Sinella curviseta Brook （Collembola： Entomobryidae） to selected heavy metals （Cu, Pb and Zn）. Survival, reproduction and growth of S. curviseta were determined in a 4-week exposure test in an agricultural soil amended with metals to concentrations of 100, 200, 400, 800, 1 600 and 3 200 mg/kg. Results showed reduction in adult survival and reproductive failure at the highest concentrations （3 200 mg/kg） of Cu and Zn. EC50reproduction values for Cu and Zn were approximately 442 and 2 760 mg/kg, respectively. Application of Pb at all levels resulted in large numbers of progeny and no significant mortality compared to controls. Adult growth rate decreased for all metal treatments compared to the controls, suggesting that metals affect S. curviseta metabolism and result in slower growth. We showed that reproduction is a slightly more sensitive parameter than growth. Since a growth test needs fewer juveniles and takes less time than a reproduction test, we conclude that the two parameters are complementary and could be used for a better ecotoxicological evaluation of contaminant levels. However, relative growth and reproduction sensitivities should be tested with more chemicals before a growth test is accepted as a faster sublethal test than a reproduction test.
