Coexistence mechanisms for species with similar ecological traits and overlapping geographic distributions are basic questions in ecology and evolutionary biology. Specific habitat requirements often limit distributio...Coexistence mechanisms for species with similar ecological traits and overlapping geographic distributions are basic questions in ecology and evolutionary biology. Specific habitat requirements often limit distribution range as well as facilitate partitioning resource utilization in ecological similar species. Understanding niche segregation and differences in microhabitat utilization can contribute to identifying coexistence mechanisms between parapatric species. Feirana quadranus and F. taihangnica are two closely related frog species with parapatric geographic ranges and an elongated contact zone within the Qinling Mountains, which is an important watershed for East Asia. Here, we analysed the difference in microhabitat utilization between the two frog species and explored the key ecological factors that induced their microhabitat differentiation based on quadrats sampled in the contact zone. Our comparison of twenty environmental variables showed that both species used microhabitats with alkalescent warm water and gentle slope conditions. The principal component analysis indicated that climate-related variables, vegetation conditions, and river width were the important factors for microhabitat utilization of these species. These findings contribute to our understanding on the coexistence mechanisms of these two related and parapatric Asian mountain frog species. This study can also be helpful for identifying target habitats to conduct conservation actions and management strategies effectively in the face of environmental changes.展开更多
Dew is an important supplement water source in arid and semi-arid areas. In order to determine the dew formation on different kinds of soils associated with various shrub species and microhabitats, we performed measur...Dew is an important supplement water source in arid and semi-arid areas. In order to determine the dew formation on different kinds of soils associated with various shrub species and microhabitats, we performed measurement of accumulated dew formation amount and duration in October 2009 in a revegetation-stabilized arid desert ecosystem in Shapotou area, northern China. The results indicated that the accumulated dew formation amount was four times larger at open spaces as compared to under the canopy, and it was nearly twice as much under living Artemisia ordosica plants(L.A.) as compared to under living Caragana korshinskii plants(L.C.). The opposite characteristics were found for dew duration between different microhabitats. Dew amounts at different vertical heights around the shrub stands were in the order of 50 cm above the canopy〉the canopy edge〉under the canopy. Dew amount continued to increase after dawn, and the proportion of average accumulated dew amount after dawn accounting for the average maximum amount increased from above the canopy to under the canopy. Dew formation duration after sunrise accounted for more than 50% of the total formation duration during the day time. Contrary to the distribution characteristics of dew amount, dew duration after dawn and total dew formation duration during the day time were both highest under the canopy, followed by at the canopy edge and then at 50 cm above the canopy. The portion of dew duration after dawn accounting for the total dew duration during the day time increased from above the canopy to under the canopy. From these results, we may conclude that dew availability as a supplemental water resource for improving the microhabitats in water-limited arid ecosystems is position dependent especially for the plant microhabitats at different stands layers.展开更多
Different microhabitats along dune slope were found to affect the distribution of plant performances and soil properties in desertified ecosystems. However, the ground-active arthropod responses to rainfall-induced du...Different microhabitats along dune slope were found to affect the distribution of plant performances and soil properties in desertified ecosystems. However, the ground-active arthropod responses to rainfall-induced dune microhabitats were largely unknown in desertified regions. At dune top, midslope and bottom, ground-active arthropods were sampled by the method of pitfall traps in addition to the herbaceous and soil measurements during spring, summer and autumn from 2012 to 2013. Ground-active arthropod had a strong dynamics in time, seasonally and yearly in responses to rainfall-induced dune microhabitats and the variations were significant higher than those of soil and herbaceous properties. The abundance distribution of dominant taxa (i.e. Melolonthidae, Carabidae, Glaphyridae, Tenebrionidae and Formicidae families) among dune microhabitats was similar between seasons within the same year, whereas they differed markedly between two sampling years with varying rainfall patterns. A significant (P〈0.05) difference in total abundance, taxa richness and Shannon index among dune microhabitats was found only in certain season time, particularly in 2013; however, no significant (P〉0.05) differences were found among dune microhabitats when averaged on three sampling seasons within the year of either 2012 or 2013. In all, the taxonomical structure differed considerably from the community structure in ground-active arthropod response to rainfall-induced dune microhabitats. The spatial distribution of taxonomical groups among dune microhabitats was significantly affected by inter-annual rainfall changes, whereas that of community structure was affected by both intra- and inter-annual rainfall changes in desertified ecosystems.展开更多
The effects of surface cracks caused by underground coal mining on microhabitat in the rhizosphere of Artem&ia ordosias were studied based on field investigation and sample analysis. The results show that the amounts...The effects of surface cracks caused by underground coal mining on microhabitat in the rhizosphere of Artem&ia ordosias were studied based on field investigation and sample analysis. The results show that the amounts of microorganisms, enzyme activity and water content in soil vary with the biomass ofA. ordosias, and that the account exhibits in an order of large A. ordosias〉medium A. ordosias〉small A. ordosias. Surface cracks apparently decrease microbial quantities and enzymatic ac- tivities, and change the composition and structure of microbial community in the rhizosphere of A. ordosias. Surface cracks reduce water content and electrical conductivity, enhance the R/S (ratio of root and soil) of water content, electrical conductivity and pH value, and raise the content of Na and Pb in rhizosphere soil ofA. ordosicas, It can be concluded that the disturbance of underground coal mining on the microhabitat in the rhizosphere ofA. ordosica is obvious in the early days.展开更多
Background:Remnant microhabitats are important for bird habitat selection and plant regeneration in the fragmented habitat.However,empirical information on the consequences of how microhabitat use by birds affects the...Background:Remnant microhabitats are important for bird habitat selection and plant regeneration in the fragmented habitat.However,empirical information on the consequences of how microhabitat use by birds affects the early recruitment of plants is lacking.Methods:In this study,we evaluated whether microhabitat selection by the Black Bulbul(Hypsipetes leucocephalus)(J.F.Gmelin,1789)impacts the early recruitment of the endangered tree species,the Chinese Yew(Taxus chinensis(Pilger)Rehd),in a fragmented forest over a 4-year period(2011–2012,2018–2019).Results:Our results showed the main factors affecting H.leucocephalus microhabitat selection were distance to the nearest T.chinensis mature tree,herb cover and density,leaf litter cover,and vegetation type.Moreover,the results of logistic regression also highlighted the importance of elevation,distance to light gap and roads,tree cover in bird microhabitat selection.Furthermore,the seed emergence rate in microhabitats used by birds did not differ from the natural forest,which was related to five factors of bird microhabitat.The Random Forest model showed that seedling emergence rate was increased with leaf litter cover and distance to fallen dead trees,but decreased in relation to herb cover,slope,and elevation.Conclusion:Our results highlight the importance of remnant microhabitats in fragmented forests for sustaining forest ecology and optimal management.The contribution of microhabitats used by birds to plant recruitment provides insights into how frugivore species contribute to plant regeneration,which should be incorporated in future conservation and management practices of fragmented forests.展开更多
This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites(copepods species, Ergasilus anchoratus Markewitsch, 1946 and Pseudergasilus parasiluri Yamaguti, 1936) and...This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites(copepods species, Ergasilus anchoratus Markewitsch, 1946 and Pseudergasilus parasiluri Yamaguti, 1936) and monogeneans (in the genus Silurodiscoides Gussev, 1976) found on gills of the fish, Silurus asotus L. from Jiangkou Reservoir in Jiangxi Province,China. E.anchoratus was the common and dominant metazoan parasite on gills of the fish in this locality as indicated by the higher infection levels, and distributed almost evenly on gill arches without any observed gill arch preference, as shown by the wide proportional distribution and broad niche breadth. P. parasiluri and monogeneans in Silurodiscoides were found also without any significant gill arch preference although they had a rather narrow niche breadth. The observed significant overlap between P. parasiluri and Silurodiscoides spp. may be simply due to the lower infection levels of the parasites. The observed pattern of unrestricted distributions of the parasitic copepods on gills of the fish may be accounted for, at least in part, by the moving ability of the copepods, and may also indicate that the parasite does not exhibit any feature of gill arch preference. However, further experimental research is needed to verify the microhabitat distribution of the parasites.展开更多
Fundamental ecological information on the Chinese kissing loach (Leptobotia tchangi) was collected in the North Tiaoxi River, China, in September 2010. The length-frequency distribution calculated using FiSAT software...Fundamental ecological information on the Chinese kissing loach (Leptobotia tchangi) was collected in the North Tiaoxi River, China, in September 2010. The length-frequency distribution calculated using FiSAT software showed the population structure of this kissing loach could be classified into four age groups suggesting that the life span of the loach should be 3 - 4 years. A stepwise multiple linear regression analysis revealed that the density of this kissing loach was significantly and positively correlated with water velocity, while the body size was significantly and positively correlated with river bed pebble size. It suggested that water velocity and variation of pebble size play important roles in the full life history of this kissing loach. Thus, maintenance of the rapid current and variety of substrate are essential for the conservation of this species under the present conditions in the river, which also can support river restoration being in harmony with survival of this kissing loach.展开更多
We quantified microhabitat use by white-footed mice Peromyscus leucopus in forest and old-field habitats occupied by Morrow' s honeysuckle Lonicera morrowii, an invasive exotic shrub imported from Japan. Microhabitat...We quantified microhabitat use by white-footed mice Peromyscus leucopus in forest and old-field habitats occupied by Morrow' s honeysuckle Lonicera morrowii, an invasive exotic shrub imported from Japan. Microhabitat characteristics were compared between trails used by mice ( n = 124) and randomly selected trails ( n = 127) in 4 study plots located at Fort Necessity National Battlefield, Farmington, Pennsylvania, USA. We compared 10 mierohabitat variables between used and random trails using non-metric multidimensional scaling (NMDS) and classification and regression tree (CART) analysis. Trails used by mice were statistically different from randomly selected trails in both forested plots ( P 〈 0. 008) and old-field plots ( P 〈 0. 001 ). In the forested plots, trails of white-footed mice were more often associated with a greater percent cover (% cover) of coarse woody debris (CWD) than were randomly selected trails. In the old-field plots, mouse trails were commonly characterized by having a lower % cover of exotic herbaceous vegetation, a greater % cover of shrubs, and a greater % cover of Morrow' s honeysuckle than randomly selected trails. Our study indicates that white-footed mice do not move randomly and prefer areas of high structural complexity, thereby showing significant microhabitat preference. The preference of white-footed mice for areas with a relatively high percent cover of Morrow's honeysuckle could 1 ) be a factor in the aggressive nature of the exotic honeysuckle shrub's spread throughout the Battlefield or 2) cause the shrub to spread even faster into adjacent areas not yet occupied by Morrow' s honeysuckle展开更多
Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed tha...Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed that the morphology of 59Fe was in a particulate state in sea water. The adsorption rule of 59Fe by three kinds of sediments was similar. The concentration ability of 59Fe by phytoplankton was very strong. The critical concentration organs of S9Fe by marine animals were viscera. The gross radioactivity of 59Fe was mainly concentrated in protein. The concentration factor of 59Fe by DNA was the highest one. After excretion experiment, 59Fe of all the tissue organs was not detected. Small part of59Fe remained in the organic acid and protein state. There was a redistribution process in sediment for59Fe.展开更多
It has been suggested that spatial heterogeneity is key to the coexistence at local spatial scales of subordinate and dominant predator species by allowing the former to shift to more protective habitats when the risk...It has been suggested that spatial heterogeneity is key to the coexistence at local spatial scales of subordinate and dominant predator species by allowing the former to shift to more protective habitats when the risk of intraguild predation exists. Here, we show how the smaller carnivore Egyptian mongoose (Herpestes ichneumon) may coexist on a local scale with its intraguild pre- dator, the Iberian lynx (Lynx pardinus), by using places with different microhabitat character- istics. We expect that mongooses living within lynx home ranges will use denser and more protective habitats when active in order to di- minish their risk of being killed by lynx com- pared to those living in areas similar in vege- tation and prey availability but where lynx are absent. The scrubland cover of points used by mongooses outside lynx areas, and that of points located within lynx areas but not used by mongooses, were significantly lower than, or similar to, cover of points used by mongooses within lynx areas. The probability of finding mon- goose tracks was constant across levels of scrubland cover when lynx were absent, but more mongoose tracks were likely to be found in thicker scrubland within lynx areas, especially if these areas were intensively used by lynx. This result agrees with the hypothesis on shifts in microhabitat use of subordinate carnivores to prevent fatal or risky encounters with dominant ones.展开更多
基金supported by National Natural Science Foundation of China (31572290, 31770568, and 31770427)Youth Innovation Promotion Association CAS (2015304)+2 种基金National Key Research and Development Plan (2016YFC0503303)China Scholarship Council (No. 201706775008)the project from Qinghai Provincial Communication Department (31118022)
文摘Coexistence mechanisms for species with similar ecological traits and overlapping geographic distributions are basic questions in ecology and evolutionary biology. Specific habitat requirements often limit distribution range as well as facilitate partitioning resource utilization in ecological similar species. Understanding niche segregation and differences in microhabitat utilization can contribute to identifying coexistence mechanisms between parapatric species. Feirana quadranus and F. taihangnica are two closely related frog species with parapatric geographic ranges and an elongated contact zone within the Qinling Mountains, which is an important watershed for East Asia. Here, we analysed the difference in microhabitat utilization between the two frog species and explored the key ecological factors that induced their microhabitat differentiation based on quadrats sampled in the contact zone. Our comparison of twenty environmental variables showed that both species used microhabitats with alkalescent warm water and gentle slope conditions. The principal component analysis indicated that climate-related variables, vegetation conditions, and river width were the important factors for microhabitat utilization of these species. These findings contribute to our understanding on the coexistence mechanisms of these two related and parapatric Asian mountain frog species. This study can also be helpful for identifying target habitats to conduct conservation actions and management strategies effectively in the face of environmental changes.
基金financially supported by the National Natural Science Foundation of China (41201085)the 100 Talents Program of the Chinese Academy of Sciences
文摘Dew is an important supplement water source in arid and semi-arid areas. In order to determine the dew formation on different kinds of soils associated with various shrub species and microhabitats, we performed measurement of accumulated dew formation amount and duration in October 2009 in a revegetation-stabilized arid desert ecosystem in Shapotou area, northern China. The results indicated that the accumulated dew formation amount was four times larger at open spaces as compared to under the canopy, and it was nearly twice as much under living Artemisia ordosica plants(L.A.) as compared to under living Caragana korshinskii plants(L.C.). The opposite characteristics were found for dew duration between different microhabitats. Dew amounts at different vertical heights around the shrub stands were in the order of 50 cm above the canopy〉the canopy edge〉under the canopy. Dew amount continued to increase after dawn, and the proportion of average accumulated dew amount after dawn accounting for the average maximum amount increased from above the canopy to under the canopy. Dew formation duration after sunrise accounted for more than 50% of the total formation duration during the day time. Contrary to the distribution characteristics of dew amount, dew duration after dawn and total dew formation duration during the day time were both highest under the canopy, followed by at the canopy edge and then at 50 cm above the canopy. The portion of dew duration after dawn accounting for the total dew duration during the day time increased from above the canopy to under the canopy. From these results, we may conclude that dew availability as a supplemental water resource for improving the microhabitats in water-limited arid ecosystems is position dependent especially for the plant microhabitats at different stands layers.
基金supported by the Science Research Foundation of Ningxia Higher Education(NGY2015053)Ningxia Natural Science Foundation(NZ15025)the National Natural Science Foundation of China(41101050)
文摘Different microhabitats along dune slope were found to affect the distribution of plant performances and soil properties in desertified ecosystems. However, the ground-active arthropod responses to rainfall-induced dune microhabitats were largely unknown in desertified regions. At dune top, midslope and bottom, ground-active arthropods were sampled by the method of pitfall traps in addition to the herbaceous and soil measurements during spring, summer and autumn from 2012 to 2013. Ground-active arthropod had a strong dynamics in time, seasonally and yearly in responses to rainfall-induced dune microhabitats and the variations were significant higher than those of soil and herbaceous properties. The abundance distribution of dominant taxa (i.e. Melolonthidae, Carabidae, Glaphyridae, Tenebrionidae and Formicidae families) among dune microhabitats was similar between seasons within the same year, whereas they differed markedly between two sampling years with varying rainfall patterns. A significant (P〈0.05) difference in total abundance, taxa richness and Shannon index among dune microhabitats was found only in certain season time, particularly in 2013; however, no significant (P〉0.05) differences were found among dune microhabitats when averaged on three sampling seasons within the year of either 2012 or 2013. In all, the taxonomical structure differed considerably from the community structure in ground-active arthropod response to rainfall-induced dune microhabitats. The spatial distribution of taxonomical groups among dune microhabitats was significantly affected by inter-annual rainfall changes, whereas that of community structure was affected by both intra- and inter-annual rainfall changes in desertified ecosystems.
文摘The effects of surface cracks caused by underground coal mining on microhabitat in the rhizosphere of Artem&ia ordosias were studied based on field investigation and sample analysis. The results show that the amounts of microorganisms, enzyme activity and water content in soil vary with the biomass ofA. ordosias, and that the account exhibits in an order of large A. ordosias〉medium A. ordosias〉small A. ordosias. Surface cracks apparently decrease microbial quantities and enzymatic ac- tivities, and change the composition and structure of microbial community in the rhizosphere of A. ordosias. Surface cracks reduce water content and electrical conductivity, enhance the R/S (ratio of root and soil) of water content, electrical conductivity and pH value, and raise the content of Na and Pb in rhizosphere soil ofA. ordosicas, It can be concluded that the disturbance of underground coal mining on the microhabitat in the rhizosphere ofA. ordosica is obvious in the early days.
基金This study was supported by the National Natural Science Foundation of China(Grant No.31700468)the Natural Science Foundation of Jiangsu Province(Grant No.BK2017636).
文摘Background:Remnant microhabitats are important for bird habitat selection and plant regeneration in the fragmented habitat.However,empirical information on the consequences of how microhabitat use by birds affects the early recruitment of plants is lacking.Methods:In this study,we evaluated whether microhabitat selection by the Black Bulbul(Hypsipetes leucocephalus)(J.F.Gmelin,1789)impacts the early recruitment of the endangered tree species,the Chinese Yew(Taxus chinensis(Pilger)Rehd),in a fragmented forest over a 4-year period(2011–2012,2018–2019).Results:Our results showed the main factors affecting H.leucocephalus microhabitat selection were distance to the nearest T.chinensis mature tree,herb cover and density,leaf litter cover,and vegetation type.Moreover,the results of logistic regression also highlighted the importance of elevation,distance to light gap and roads,tree cover in bird microhabitat selection.Furthermore,the seed emergence rate in microhabitats used by birds did not differ from the natural forest,which was related to five factors of bird microhabitat.The Random Forest model showed that seedling emergence rate was increased with leaf litter cover and distance to fallen dead trees,but decreased in relation to herb cover,slope,and elevation.Conclusion:Our results highlight the importance of remnant microhabitats in fragmented forests for sustaining forest ecology and optimal management.The contribution of microhabitats used by birds to plant recruitment provides insights into how frugivore species contribute to plant regeneration,which should be incorporated in future conservation and management practices of fragmented forests.
文摘This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites(copepods species, Ergasilus anchoratus Markewitsch, 1946 and Pseudergasilus parasiluri Yamaguti, 1936) and monogeneans (in the genus Silurodiscoides Gussev, 1976) found on gills of the fish, Silurus asotus L. from Jiangkou Reservoir in Jiangxi Province,China. E.anchoratus was the common and dominant metazoan parasite on gills of the fish in this locality as indicated by the higher infection levels, and distributed almost evenly on gill arches without any observed gill arch preference, as shown by the wide proportional distribution and broad niche breadth. P. parasiluri and monogeneans in Silurodiscoides were found also without any significant gill arch preference although they had a rather narrow niche breadth. The observed significant overlap between P. parasiluri and Silurodiscoides spp. may be simply due to the lower infection levels of the parasites. The observed pattern of unrestricted distributions of the parasitic copepods on gills of the fish may be accounted for, at least in part, by the moving ability of the copepods, and may also indicate that the parasite does not exhibit any feature of gill arch preference. However, further experimental research is needed to verify the microhabitat distribution of the parasites.
文摘Fundamental ecological information on the Chinese kissing loach (Leptobotia tchangi) was collected in the North Tiaoxi River, China, in September 2010. The length-frequency distribution calculated using FiSAT software showed the population structure of this kissing loach could be classified into four age groups suggesting that the life span of the loach should be 3 - 4 years. A stepwise multiple linear regression analysis revealed that the density of this kissing loach was significantly and positively correlated with water velocity, while the body size was significantly and positively correlated with river bed pebble size. It suggested that water velocity and variation of pebble size play important roles in the full life history of this kissing loach. Thus, maintenance of the rapid current and variety of substrate are essential for the conservation of this species under the present conditions in the river, which also can support river restoration being in harmony with survival of this kissing loach.
基金the National Park Service, U. S. Department of the Interior
文摘We quantified microhabitat use by white-footed mice Peromyscus leucopus in forest and old-field habitats occupied by Morrow' s honeysuckle Lonicera morrowii, an invasive exotic shrub imported from Japan. Microhabitat characteristics were compared between trails used by mice ( n = 124) and randomly selected trails ( n = 127) in 4 study plots located at Fort Necessity National Battlefield, Farmington, Pennsylvania, USA. We compared 10 mierohabitat variables between used and random trails using non-metric multidimensional scaling (NMDS) and classification and regression tree (CART) analysis. Trails used by mice were statistically different from randomly selected trails in both forested plots ( P 〈 0. 008) and old-field plots ( P 〈 0. 001 ). In the forested plots, trails of white-footed mice were more often associated with a greater percent cover (% cover) of coarse woody debris (CWD) than were randomly selected trails. In the old-field plots, mouse trails were commonly characterized by having a lower % cover of exotic herbaceous vegetation, a greater % cover of shrubs, and a greater % cover of Morrow' s honeysuckle than randomly selected trails. Our study indicates that white-footed mice do not move randomly and prefer areas of high structural complexity, thereby showing significant microhabitat preference. The preference of white-footed mice for areas with a relatively high percent cover of Morrow's honeysuckle could 1 ) be a factor in the aggressive nature of the exotic honeysuckle shrub's spread throughout the Battlefield or 2) cause the shrub to spread even faster into adjacent areas not yet occupied by Morrow' s honeysuckle
文摘Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed that the morphology of 59Fe was in a particulate state in sea water. The adsorption rule of 59Fe by three kinds of sediments was similar. The concentration ability of 59Fe by phytoplankton was very strong. The critical concentration organs of S9Fe by marine animals were viscera. The gross radioactivity of 59Fe was mainly concentrated in protein. The concentration factor of 59Fe by DNA was the highest one. After excretion experiment, 59Fe of all the tissue organs was not detected. Small part of59Fe remained in the organic acid and protein state. There was a redistribution process in sediment for59Fe.
基金funded by project CGL2004-00346/BOS of Ministry of Education and Sciencesupported by a predoctoral grant of CSIC-Spanish Council for Research,“I3P”programsupported by a FPU and a post-doctoral fellowships from the Spanish Ministry of Education.
文摘It has been suggested that spatial heterogeneity is key to the coexistence at local spatial scales of subordinate and dominant predator species by allowing the former to shift to more protective habitats when the risk of intraguild predation exists. Here, we show how the smaller carnivore Egyptian mongoose (Herpestes ichneumon) may coexist on a local scale with its intraguild pre- dator, the Iberian lynx (Lynx pardinus), by using places with different microhabitat character- istics. We expect that mongooses living within lynx home ranges will use denser and more protective habitats when active in order to di- minish their risk of being killed by lynx com- pared to those living in areas similar in vege- tation and prey availability but where lynx are absent. The scrubland cover of points used by mongooses outside lynx areas, and that of points located within lynx areas but not used by mongooses, were significantly lower than, or similar to, cover of points used by mongooses within lynx areas. The probability of finding mon- goose tracks was constant across levels of scrubland cover when lynx were absent, but more mongoose tracks were likely to be found in thicker scrubland within lynx areas, especially if these areas were intensively used by lynx. This result agrees with the hypothesis on shifts in microhabitat use of subordinate carnivores to prevent fatal or risky encounters with dominant ones.