Ecosystem engineers are organisms that alter the distribution of resources in the environment by creating,modifying,maintaining and/or destroying the habitat.They can affect the structure and function of the whole eco...Ecosystem engineers are organisms that alter the distribution of resources in the environment by creating,modifying,maintaining and/or destroying the habitat.They can affect the structure and function of the whole ecosystem furthermore.Burrowing engineers are an important group in ecosystem engineers as they play a critical role in soil translocation and habitat creation in various types of environment.However,few researchers have systematically summarized and analyzed the studies of burrowing engineers.We reviewing the existing ecological studies of burrowing engineer about their interaction with habitat through five directions:(1)soil turnover;(2)changing soil physicochemical properties;(3)changing plant community structure;(4)providing limited resources for commensal animals;and/or(5)affecting animal communities.The Chinese pangolin(Manis pentadactyla)is a typical example of burrowing mammals,in part(5),we focus on the interspecific relationships among burrow commensal species of Chinese pangolin.The engineering effects vary with environmental gradient,literature indicates that burrowing engineer play a stronger role in habitat transformation in the tropical and subtropical areas.The most common experiment method is comparative measurements(include different spatial and temporal scale),manipulative experiment is relatively few.We found that most of the engineering effects had positive feedback to the local ecosystem,increased plant abundance and resilience,increased biodiversity and consequently improved ecosystem functioning.With the global background of dramatic climate change and biodiversity loss in recent decades,we recommend future studies should improving knowledge of long-term engineering effects on population scale and landscape scale,exploring ecological cascades through trophic and engineering pathways,to better understand the attribute of the burrowing behavior of engineers to restore ecosystems and habitat creation.The review is presented as an aid to systematically expound the engineering effect of burrowing animals in the ecosystem,and provided new ideas and advice for planning and implementing conservation management.展开更多
Abundant burrows of Skolithos linearis, Palaeophycus tubularis, and Taenidium barretti are preserved in the Upper Devonian Donghe sandstone of Tarim basin, China. They are commonly highlighted in core by the color of ...Abundant burrows of Skolithos linearis, Palaeophycus tubularis, and Taenidium barretti are preserved in the Upper Devonian Donghe sandstone of Tarim basin, China. They are commonly highlighted in core by the color of the burrow fill in contrast to the surrounding matrix and have dif-ferent textures and fabrics from the matrix. There are three kinds of calcite cements in burrows, microcrystalline-crystalline calcite cement, mosaic calcite cement, and ferroan calcite cement. Microcrystalline-crystalline calcite cement is widely distributed in the lower part of the Donghe sand-stone, but it is rare in burrows filling. It displays a globule structure under burial cementation and sel-dom replaces the quartz grains in shallow burial depth stage. Mosaiccalcite cement is widespread in the Donghe sansdtone reservoir of North Tarim basin. It shows chrysoidine, orange and bright orange lu-minescence, and intensely replaces the quartz grains, forming in early diagenetic and shallow burial depth stage. Ferroan calcite is asymmetrically distributed in the Donghe sandstone reservoir of Central Tarim basin. It fills the remanent pores in the shape of mosaic and replaces the quartz grains, matrix, and early calcite cement, forming in late diagenetic and deep burial depth stage. The burrows filled with white calcite cements have low oil saturation or may be oil-stained. In contrast, there is high oil saturation in the sandstone reservoir where the bioturbation is sparse or not present. With increased bioturbation, the porosity, permeability, and oil saturation decrease; thus, bioturbation intensity and reservoir property appear to be negatively correlated.展开更多
Burrow structural charactersitcs and microhabitat use of the Turpan wonder gecko Teratoscincus roborowskii （Gekkonidae） were studied between April and September of 2013 in the Turpan Eremophytes Botanic Garden, in t...Burrow structural charactersitcs and microhabitat use of the Turpan wonder gecko Teratoscincus roborowskii （Gekkonidae） were studied between April and September of 2013 in the Turpan Eremophytes Botanic Garden, in the Turpan Depression of Western China. Burrow depth, entrance orientation, entrance height and width were observed. We assessed microhabitat selection and noted differences in microhabitat use among males, females, and juveniles. The magnitude of selection was measured using Jacobs＇ index of selectivity. Entrance height and width of the burrows of adults were significantly larger than those of juveniles, but the difference in burrow depth was not significant. The directional orientation of the burrow entrance showed a preference for the north-northeast and south-southeast, which were likely influenced by local prevailing winds and sunlight. Both the adult and juvenile geckos prefer to construct their burrows in sandy soil within a layer of loose soil whose thickness is greater than 30 cm. A majority of the burrows were located within 20 m of the nearest plant. Nearly half （48%） of the entrances of juveniles were located within 5 m of the nearest vegetation, significantly different from those of the adults. Results showed that the Turpan wonder gecko did not utilize microhabitats according to their availability, but rather that it preferred rnicrohabitats which contained dead wood or the caper bush. Our results suggested that burrow characteristics and microhabitat selection were important factors in T. roborowskii adaptation to harsh and arid desert habitats.展开更多
Two new tetrapod burrow casts from the Naobaogou Formation （Middle or Late Permian） of Nei Mongol,China are described.It marks the first pre-Cenozoic tetrapod burrow from China,and one of the earliest records of tet...Two new tetrapod burrow casts from the Naobaogou Formation （Middle or Late Permian） of Nei Mongol,China are described.It marks the first pre-Cenozoic tetrapod burrow from China,and one of the earliest records of tetrapod burrows.Comparison to other Permian and Triassic burrows suggests that these burrows were created by tetrapod slightly smaller than Lystrosaurus.Deduced from the morphology and sizes of two burrows and known tetrapods of the Naobaogou Formation,the burrow should be the production of a therapsid,most likely a dicynodon.These burrows indicate a seasonal climate and this area was semiarid or arid during that time.展开更多
Background： Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are d...Background： Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are designed to restore the structure, processes as well as related physical, chemical and biological characteristics of wetlands and to ensure the provision of ecosystem services. As important components of mangrove ecosystem, benthic organisms and crabs play a key role in nutrient cycling. In addition, mangrove restoration, such as vegetation restoration measures, can lead to changes in the benthic faunal communities. This study investigates whether the presence of different mangrove species, age and canopy cover of mangrove communities affect the density of crab burrows. Methods： The Luoyangjiang Estuary, in the southeast of Fujian Province, was selected as our research area. A survey, covering 14 sites, was conducted to investigate the impacts of mangrove restoration on the density of crab burrows in four rehabilitated forests with different stand ages and canopy. Results： It was found that differences in vegetation types had a large impact on crab density and that the density of crab burrows was lower on exposed beaches （non-mangrove） than under mature Kondelio condel, Aegiceros corniculatum and Avicennio morina communities. In general, the amount of leaf litter and debris on mangrove mudfiats was greater than on the beaches as food sources for crabs. Two-factor analysis of variance （ANOVA） shows that changes in mangrove species and age since restoration had different effects on crab burrow density. The effect of canopy cover was highly significant on crab burrow density. Conclusions： The results suggest that in the process of mangrove restoration the combined effects of mangrove stand age, canopy cover and other factors should be taken into account. This study further supports the findings of the future scientific research and practice on mangrove restoration and management measures.展开更多
Oxygen is one of the important substances for the survival of most life systems on the earth,and plateau and underground burrow systems are two typical hypoxic environments.Small mammals living in hypoxic environments...Oxygen is one of the important substances for the survival of most life systems on the earth,and plateau and underground burrow systems are two typical hypoxic environments.Small mammals living in hypoxic environments have evolved different adaptation strategies,which include increased oxygen delivery,metabolic regulation of physiological responses and other physiological responses that change tissue oxygen utilization.Multiomics predictions have also shown that these animals have evolved different adaptations to extreme environments.In particular,vascular endothelial growth factor(VEGF)and erythropoietin(EPO),which have specific functions in the control of O_(2) delivery,have evolved adaptively in small mammals in hypoxic environments.Naked mole-rats and blind mole-rats are typical hypoxic model animals as they have some resistance to cancer.This review primarily summarizes the main living environment of hypoxia tolerant small mammals,as well as the changes of phenotype,physiochemical characteristics and gene expression mode of their long-term living in hypoxia environment.展开更多
In grassland ecosystems,burrowing mammals create disturbances,providing habitat for animal species and increasing plant community diversity.We investigated whether seedling assemblages on Richardson's ground squir...In grassland ecosystems,burrowing mammals create disturbances,providing habitat for animal species and increasing plant community diversity.We investigated whether seedling assemblages on Richardson's ground squirrel Urocitellus richardsonii mounds result from seed rearrangement or environmental changes that favor germination of certain species over others.To test whether ground squirrels rearrange the seed bank by burrowing,we compared seed compositions among mounds,burrows,and undisturbed soil.To test whether ground squirrels change environmental conditions,we compared soil nitrate and bare ground cover on and off mounds.We also compared seedlings that germinated on mounds with seedlings that germinated on artificial disturbances from which we removed aboveground vegetation.Soil nitrate and bare ground cover were significantly higher on mounds than artificial disturbances.While seed richness and abundance did not differ among mounds,burrows,and undisturbed soil,seedling richness was reduced on mounds relative to artificial disturbances.Burrowing disturbance favors seedlings that can capitalize on bare ground availability but are less able to immobilize nitrate,as opposed to perennial species that immobilize more nitrate but take longer to establish.Our results suggest that Richardson's ground squirrels act as ecosystem engineers,although future research following succession on ground squirrel mounds is necessary to understand how they influence plant communities past the seedling stage.展开更多
Perinereis aibuhitensis(Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data...Perinereis aibuhitensis(Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data for the habitat selection and suitability evaluations of the artificial aquaculture of P. aibuhitensis, this paper conducted a quantified analysis of its burrowing ability and explored its behavioral preferences in different substrates,including mud(<75 μm), fine sand(125–250 μm), medium sand(250–500 μm), coarse sand(500–2 000 μm), gravel(2 000–4 000 μm) and ceramsite(4 000–8 000 μm). The research results revealed that substrate grain size significantly affected the burrowing time, burrowing rate, burrowing depth and distribution rate(P<0.01).Moreover, P. aibuhitensis demonstrated preferential selections relating to substrate grain sizes, had higher burrowing ability in ceramsite, mud and fine sand compared with other substrates. The strongest burrowing ability and the highest distribution rate were observed in ceramsite. The study indicated that P. aibuhitensis was sensitive to substrate grain size, which also had an impact on its burrowing process and population distribution.In the natural sea, substrates mainly composed of mud and fine sand are fit for aquaculture and stock enhancement. Based on behavioral preferences and ecological rehabilitation function of P. aibuhitensis, this paper proposes a symbiotic system of marine animals and halophytes, and constructs an ecosystem model of"Marine fish-Halophytes-Perinereis aibuhitensis" with P. aibuhitensis as the link.展开更多
The present study describes the habitats, life cycle, larvae growth, burrowing behavior and terrestrial adaptation of Spadefoot toads in Israel based on observations and data collected during more than 30 years in nor...The present study describes the habitats, life cycle, larvae growth, burrowing behavior and terrestrial adaptation of Spadefoot toads in Israel based on observations and data collected during more than 30 years in northern Israel. The distribution area in Israel is from the north in the Upper Galilee and Golan Heights (annual rainfall range of 500 - 1000 mm) to the southern coastal plain (annual rainfall of about 250 mm). Among the 51 different breeding places of amphibians, only ponds where water was available for a few months were used by Spadefoot toads and metamorphosed populations were found around these ponds. The larvae underwent metamorphosis during the summer and autumn in northern Israel, and during the spring in central and southern Israel. A negative correlation exists between the percentage of toads burrowing and soil moisture levels, with greater burrowing behavior occurring under dry conditions. The plasma concentration increased during burrowing by electrolytes and urea accumulations. The burrowing behavior helped Spadefoot toads survive in this area at the southern border of its distribution.展开更多
<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The...<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm<sup><span style="font-family:Verdana;">2</sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm<sup><span style="font-family:Verdana;">2</sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm<sup><span style="font-family:Verdana;">2</sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (<span style="font-family:Verdana;">n <span style="font-family:Verdana;">= 55) followed by medium (<span style="font-family:Verdana;">n <span style="font-family:Verdana;">= 30) and highly (<span style="font-family:Verdana;">n<span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.展开更多
Globally,grassland degradation is an acute ecological problem.In alpine grassland on the Tibetan Plateau,increased densities of various small mammals in degraded grassland are assumed to intensify the degradation proc...Globally,grassland degradation is an acute ecological problem.In alpine grassland on the Tibetan Plateau,increased densities of various small mammals in degraded grassland are assumed to intensify the degradation process and these mammals are subject to lethal control.However,whether the negative impact of small mammals is solely a result of population size or also a result of activity and behavior has not been tested.In this study,we use plateau pika as a model to compare population size,core area of colony,and the number of burrow entrances and latrines between lightly and severely degraded grassland.We test whether the alleged contribution of pika to grassland degradation is a result of increased population size or increased burrowing activities of individuals in response to lower food abundance.We found that grassland degradation resulted in lower plant species richness,plant height,and biomass.Furthermore,the overall population size of pika was not significantly affected by location in lightly and severely degraded grassland.However,pika core areas in severely grassland degradation were significantly larger and had significantly higher densities of burrows and latrines.Our study provides convincing evidence that habitat-induced changes in the behavior of small,burrowing mammals,such as pika,can exacerbate grassland degradation.This finding has significant implications for managing small mammals and restoring degraded grassland ecosystems.展开更多
The continuous excavation of burrows by fiddler crabs generates bioturbation in the sediment,which can be estimated from burrow morphology.The aim of the present study was to describe the burrow morphology of Uca urug...The continuous excavation of burrows by fiddler crabs generates bioturbation in the sediment,which can be estimated from burrow morphology.The aim of the present study was to describe the burrow morphology of Uca uruguayensis and U.leptodactylus and its relationship with demography of resident individuals and to estimate the level of bioturbation in the sediment generated by each species.For all individuals from each of the 2 species,sex was determined and the carapace width(CW;mm)measured.Burrows were characterized according to burrow diameter(BD;mm),maximum burrow depth(MBD;mm)and burrow volume(BV;cm^(3)).The density of each species in the study area was also evaluated.In both species,the males were larger and occupied burrows with higher BV compared to females.Differences between sexes in relation to the burrow characteristics might reflect sexual dimorphism within the group and are probably related to the fact that males use the burrows for mating.BD and BV showed significant positive relationships with the size of resident crabs.The amount of sediment removed per burrow was estimated from mean BV:10.78 cm^(3)of sediment/burrow for U.uruguayensis and 12.38 cm^(3)of sediment/burrow for U.leptodactylus.Despite the density and depth differences between the 2 species,the similarity in burrow volume suggests that U.uruguayensis and U.leptodactylus present the same importance in terms of the bioturbation process.Burrow morphology is highly associated with characteristics of the occupant,although extrinsic factors should also be considered,and its description can provide estimates on the bioturbation generated by Uca species in mangrove forests.展开更多
Loach exhibit conspicuous drilling behaviors in the mud of shallow waters,yet their burrow morphology and the factors affecting this behavior have received little attention.We characterized the burrow morphology and w...Loach exhibit conspicuous drilling behaviors in the mud of shallow waters,yet their burrow morphology and the factors affecting this behavior have received little attention.We characterized the burrow morphology and water quality of the pond loach Misgurnus anguillicaudatus in three scenarios:in tanks without plants,tanks with the free-floating plant water hyacinth Eichhornia crassipes,and tanks with water lettuce Pistia stratiotes.Water hyacinth effectively removed water TN,COD,NO3-N and NH4-N,and water lettuce removed water TP and NH4-N.Water hyacinth and water lettuce markedly reduced water turbidity and DO,increased TOC and EC.Water hyacinth purified water more effectively than water lettuce,providing a suitable habitat for loach feeding,living and burrowing.The burrow structures were V-shaped,Y-shaped,inverted L-shaped,or complicated dendritic networks composed of multiple V shapes.The hyacinth treatment was characterized by the greatest burrow volume,length,depth,and structural complexity,but the opening size was reduced by dense root mat coverage.Burrows in the water lettuce treatment were characterized by intermediate volume,length,branches and sinuosity,but they had the largest opening and pit size.The control treatment had a flat bottom with the smallest,shortest burrows.This study indicates that free-floating plants improve habitat suitability and change burrow morphology and may be used to improve loach breeding methods。展开更多
基金This article is supported by Rare and endangered Species Investigation supervision and industry standard project of State Forestry and Grassland Administration(2020070215)This article is supported by Rare and endangered Species Investigation supervision and industry standard project of State Forestry and Grassland Administration(2020070215).
文摘Ecosystem engineers are organisms that alter the distribution of resources in the environment by creating,modifying,maintaining and/or destroying the habitat.They can affect the structure and function of the whole ecosystem furthermore.Burrowing engineers are an important group in ecosystem engineers as they play a critical role in soil translocation and habitat creation in various types of environment.However,few researchers have systematically summarized and analyzed the studies of burrowing engineers.We reviewing the existing ecological studies of burrowing engineer about their interaction with habitat through five directions:(1)soil turnover;(2)changing soil physicochemical properties;(3)changing plant community structure;(4)providing limited resources for commensal animals;and/or(5)affecting animal communities.The Chinese pangolin(Manis pentadactyla)is a typical example of burrowing mammals,in part(5),we focus on the interspecific relationships among burrow commensal species of Chinese pangolin.The engineering effects vary with environmental gradient,literature indicates that burrowing engineer play a stronger role in habitat transformation in the tropical and subtropical areas.The most common experiment method is comparative measurements(include different spatial and temporal scale),manipulative experiment is relatively few.We found that most of the engineering effects had positive feedback to the local ecosystem,increased plant abundance and resilience,increased biodiversity and consequently improved ecosystem functioning.With the global background of dramatic climate change and biodiversity loss in recent decades,we recommend future studies should improving knowledge of long-term engineering effects on population scale and landscape scale,exploring ecological cascades through trophic and engineering pathways,to better understand the attribute of the burrowing behavior of engineers to restore ecosystems and habitat creation.The review is presented as an aid to systematically expound the engineering effect of burrowing animals in the ecosystem,and provided new ideas and advice for planning and implementing conservation management.
基金supported by the National Natural Science Foundation of China (No. 4072003)Fostering Foundation of Henan Polytechnic University for the Excellent PhD Dissertation (No. 2011011001)
文摘Abundant burrows of Skolithos linearis, Palaeophycus tubularis, and Taenidium barretti are preserved in the Upper Devonian Donghe sandstone of Tarim basin, China. They are commonly highlighted in core by the color of the burrow fill in contrast to the surrounding matrix and have dif-ferent textures and fabrics from the matrix. There are three kinds of calcite cements in burrows, microcrystalline-crystalline calcite cement, mosaic calcite cement, and ferroan calcite cement. Microcrystalline-crystalline calcite cement is widely distributed in the lower part of the Donghe sand-stone, but it is rare in burrows filling. It displays a globule structure under burial cementation and sel-dom replaces the quartz grains in shallow burial depth stage. Mosaiccalcite cement is widespread in the Donghe sansdtone reservoir of North Tarim basin. It shows chrysoidine, orange and bright orange lu-minescence, and intensely replaces the quartz grains, forming in early diagenetic and shallow burial depth stage. Ferroan calcite is asymmetrically distributed in the Donghe sandstone reservoir of Central Tarim basin. It fills the remanent pores in the shape of mosaic and replaces the quartz grains, matrix, and early calcite cement, forming in late diagenetic and deep burial depth stage. The burrows filled with white calcite cements have low oil saturation or may be oil-stained. In contrast, there is high oil saturation in the sandstone reservoir where the bioturbation is sparse or not present. With increased bioturbation, the porosity, permeability, and oil saturation decrease; thus, bioturbation intensity and reservoir property appear to be negatively correlated.
基金funded by the National Natural Science Foundation of China(31260511,31660613)
文摘Burrow structural charactersitcs and microhabitat use of the Turpan wonder gecko Teratoscincus roborowskii （Gekkonidae） were studied between April and September of 2013 in the Turpan Eremophytes Botanic Garden, in the Turpan Depression of Western China. Burrow depth, entrance orientation, entrance height and width were observed. We assessed microhabitat selection and noted differences in microhabitat use among males, females, and juveniles. The magnitude of selection was measured using Jacobs＇ index of selectivity. Entrance height and width of the burrows of adults were significantly larger than those of juveniles, but the difference in burrow depth was not significant. The directional orientation of the burrow entrance showed a preference for the north-northeast and south-southeast, which were likely influenced by local prevailing winds and sunlight. Both the adult and juvenile geckos prefer to construct their burrows in sandy soil within a layer of loose soil whose thickness is greater than 30 cm. A majority of the burrows were located within 20 m of the nearest plant. Nearly half （48%） of the entrances of juveniles were located within 5 m of the nearest vegetation, significantly different from those of the adults. Results showed that the Turpan wonder gecko did not utilize microhabitats according to their availability, but rather that it preferred rnicrohabitats which contained dead wood or the caper bush. Our results suggested that burrow characteristics and microhabitat selection were important factors in T. roborowskii adaptation to harsh and arid desert habitats.
基金funded by 973 Program of China (Grant No. 2012CB821902)National Science Foundation of China (40972014)Chinese Academy of Sciences (KZCX2-YW-BR-07)
文摘Two new tetrapod burrow casts from the Naobaogou Formation （Middle or Late Permian） of Nei Mongol,China are described.It marks the first pre-Cenozoic tetrapod burrow from China,and one of the earliest records of tetrapod burrows.Comparison to other Permian and Triassic burrows suggests that these burrows were created by tetrapod slightly smaller than Lystrosaurus.Deduced from the morphology and sizes of two burrows and known tetrapods of the Naobaogou Formation,the burrow should be the production of a therapsid,most likely a dicynodon.These burrows indicate a seasonal climate and this area was semiarid or arid during that time.
基金funded by the Special Forestry Project of Public Interests(201404305)
文摘Background： Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are designed to restore the structure, processes as well as related physical, chemical and biological characteristics of wetlands and to ensure the provision of ecosystem services. As important components of mangrove ecosystem, benthic organisms and crabs play a key role in nutrient cycling. In addition, mangrove restoration, such as vegetation restoration measures, can lead to changes in the benthic faunal communities. This study investigates whether the presence of different mangrove species, age and canopy cover of mangrove communities affect the density of crab burrows. Methods： The Luoyangjiang Estuary, in the southeast of Fujian Province, was selected as our research area. A survey, covering 14 sites, was conducted to investigate the impacts of mangrove restoration on the density of crab burrows in four rehabilitated forests with different stand ages and canopy. Results： It was found that differences in vegetation types had a large impact on crab density and that the density of crab burrows was lower on exposed beaches （non-mangrove） than under mature Kondelio condel, Aegiceros corniculatum and Avicennio morina communities. In general, the amount of leaf litter and debris on mangrove mudfiats was greater than on the beaches as food sources for crabs. Two-factor analysis of variance （ANOVA） shows that changes in mangrove species and age since restoration had different effects on crab burrow density. The effect of canopy cover was highly significant on crab burrow density. Conclusions： The results suggest that in the process of mangrove restoration the combined effects of mangrove stand age, canopy cover and other factors should be taken into account. This study further supports the findings of the future scientific research and practice on mangrove restoration and management measures.
基金This work was supported by the National Natural Science Foundation of China,Grant No.U2004152.
文摘Oxygen is one of the important substances for the survival of most life systems on the earth,and plateau and underground burrow systems are two typical hypoxic environments.Small mammals living in hypoxic environments have evolved different adaptation strategies,which include increased oxygen delivery,metabolic regulation of physiological responses and other physiological responses that change tissue oxygen utilization.Multiomics predictions have also shown that these animals have evolved different adaptations to extreme environments.In particular,vascular endothelial growth factor(VEGF)and erythropoietin(EPO),which have specific functions in the control of O_(2) delivery,have evolved adaptively in small mammals in hypoxic environments.Naked mole-rats and blind mole-rats are typical hypoxic model animals as they have some resistance to cancer.This review primarily summarizes the main living environment of hypoxia tolerant small mammals,as well as the changes of phenotype,physiochemical characteristics and gene expression mode of their long-term living in hypoxia environment.
基金Natural Sciences and Engineering Research Council of Canada(NSERC)Postgraduate Scholarship awarded to L.J.N.and a NSERC Discovery Grant(154271)awarded to J.F.H.
文摘In grassland ecosystems,burrowing mammals create disturbances,providing habitat for animal species and increasing plant community diversity.We investigated whether seedling assemblages on Richardson's ground squirrel Urocitellus richardsonii mounds result from seed rearrangement or environmental changes that favor germination of certain species over others.To test whether ground squirrels rearrange the seed bank by burrowing,we compared seed compositions among mounds,burrows,and undisturbed soil.To test whether ground squirrels change environmental conditions,we compared soil nitrate and bare ground cover on and off mounds.We also compared seedlings that germinated on mounds with seedlings that germinated on artificial disturbances from which we removed aboveground vegetation.Soil nitrate and bare ground cover were significantly higher on mounds than artificial disturbances.While seed richness and abundance did not differ among mounds,burrows,and undisturbed soil,seedling richness was reduced on mounds relative to artificial disturbances.Burrowing disturbance favors seedlings that can capitalize on bare ground availability but are less able to immobilize nitrate,as opposed to perennial species that immobilize more nitrate but take longer to establish.Our results suggest that Richardson's ground squirrels act as ecosystem engineers,although future research following succession on ground squirrel mounds is necessary to understand how they influence plant communities past the seedling stage.
基金The Weifang Sci-tech Development Project under contract No.2015ZJ1042the Research on New Model of Marine Ecological Farming and Intelligent Monitoring System under contract No.H2016-02
文摘Perinereis aibuhitensis(Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data for the habitat selection and suitability evaluations of the artificial aquaculture of P. aibuhitensis, this paper conducted a quantified analysis of its burrowing ability and explored its behavioral preferences in different substrates,including mud(<75 μm), fine sand(125–250 μm), medium sand(250–500 μm), coarse sand(500–2 000 μm), gravel(2 000–4 000 μm) and ceramsite(4 000–8 000 μm). The research results revealed that substrate grain size significantly affected the burrowing time, burrowing rate, burrowing depth and distribution rate(P<0.01).Moreover, P. aibuhitensis demonstrated preferential selections relating to substrate grain sizes, had higher burrowing ability in ceramsite, mud and fine sand compared with other substrates. The strongest burrowing ability and the highest distribution rate were observed in ceramsite. The study indicated that P. aibuhitensis was sensitive to substrate grain size, which also had an impact on its burrowing process and population distribution.In the natural sea, substrates mainly composed of mud and fine sand are fit for aquaculture and stock enhancement. Based on behavioral preferences and ecological rehabilitation function of P. aibuhitensis, this paper proposes a symbiotic system of marine animals and halophytes, and constructs an ecosystem model of"Marine fish-Halophytes-Perinereis aibuhitensis" with P. aibuhitensis as the link.
文摘The present study describes the habitats, life cycle, larvae growth, burrowing behavior and terrestrial adaptation of Spadefoot toads in Israel based on observations and data collected during more than 30 years in northern Israel. The distribution area in Israel is from the north in the Upper Galilee and Golan Heights (annual rainfall range of 500 - 1000 mm) to the southern coastal plain (annual rainfall of about 250 mm). Among the 51 different breeding places of amphibians, only ponds where water was available for a few months were used by Spadefoot toads and metamorphosed populations were found around these ponds. The larvae underwent metamorphosis during the summer and autumn in northern Israel, and during the spring in central and southern Israel. A negative correlation exists between the percentage of toads burrowing and soil moisture levels, with greater burrowing behavior occurring under dry conditions. The plasma concentration increased during burrowing by electrolytes and urea accumulations. The burrowing behavior helped Spadefoot toads survive in this area at the southern border of its distribution.
文摘<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm<sup><span style="font-family:Verdana;">2</sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm<sup><span style="font-family:Verdana;">2</sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm<sup><span style="font-family:Verdana;">2</sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (<span style="font-family:Verdana;">n <span style="font-family:Verdana;">= 55) followed by medium (<span style="font-family:Verdana;">n <span style="font-family:Verdana;">= 30) and highly (<span style="font-family:Verdana;">n<span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.
基金supported by the National Natural Science Foundation of China(Grant No.32192461).
文摘Globally,grassland degradation is an acute ecological problem.In alpine grassland on the Tibetan Plateau,increased densities of various small mammals in degraded grassland are assumed to intensify the degradation process and these mammals are subject to lethal control.However,whether the negative impact of small mammals is solely a result of population size or also a result of activity and behavior has not been tested.In this study,we use plateau pika as a model to compare population size,core area of colony,and the number of burrow entrances and latrines between lightly and severely degraded grassland.We test whether the alleged contribution of pika to grassland degradation is a result of increased population size or increased burrowing activities of individuals in response to lower food abundance.We found that grassland degradation resulted in lower plant species richness,plant height,and biomass.Furthermore,the overall population size of pika was not significantly affected by location in lightly and severely degraded grassland.However,pika core areas in severely grassland degradation were significantly larger and had significantly higher densities of burrows and latrines.Our study provides convincing evidence that habitat-induced changes in the behavior of small,burrowing mammals,such as pika,can exacerbate grassland degradation.This finding has significant implications for managing small mammals and restoring degraded grassland ecosystems.
基金The Fundação de AmparoàPesquisa do Estado de São Paulo provided the first author a scientific undergraduate scholarship(2010/01252-5)。
文摘The continuous excavation of burrows by fiddler crabs generates bioturbation in the sediment,which can be estimated from burrow morphology.The aim of the present study was to describe the burrow morphology of Uca uruguayensis and U.leptodactylus and its relationship with demography of resident individuals and to estimate the level of bioturbation in the sediment generated by each species.For all individuals from each of the 2 species,sex was determined and the carapace width(CW;mm)measured.Burrows were characterized according to burrow diameter(BD;mm),maximum burrow depth(MBD;mm)and burrow volume(BV;cm^(3)).The density of each species in the study area was also evaluated.In both species,the males were larger and occupied burrows with higher BV compared to females.Differences between sexes in relation to the burrow characteristics might reflect sexual dimorphism within the group and are probably related to the fact that males use the burrows for mating.BD and BV showed significant positive relationships with the size of resident crabs.The amount of sediment removed per burrow was estimated from mean BV:10.78 cm^(3)of sediment/burrow for U.uruguayensis and 12.38 cm^(3)of sediment/burrow for U.leptodactylus.Despite the density and depth differences between the 2 species,the similarity in burrow volume suggests that U.uruguayensis and U.leptodactylus present the same importance in terms of the bioturbation process.Burrow morphology is highly associated with characteristics of the occupant,although extrinsic factors should also be considered,and its description can provide estimates on the bioturbation generated by Uca species in mangrove forests.
基金This study was financially supported by the Natural Science Foundation of the Science and Technology Commission of Shanghai Municipality(Grant No.13ZR1427300)Spark Program of the state ministry of science and technology of China(2015GA680005).
文摘Loach exhibit conspicuous drilling behaviors in the mud of shallow waters,yet their burrow morphology and the factors affecting this behavior have received little attention.We characterized the burrow morphology and water quality of the pond loach Misgurnus anguillicaudatus in three scenarios:in tanks without plants,tanks with the free-floating plant water hyacinth Eichhornia crassipes,and tanks with water lettuce Pistia stratiotes.Water hyacinth effectively removed water TN,COD,NO3-N and NH4-N,and water lettuce removed water TP and NH4-N.Water hyacinth and water lettuce markedly reduced water turbidity and DO,increased TOC and EC.Water hyacinth purified water more effectively than water lettuce,providing a suitable habitat for loach feeding,living and burrowing.The burrow structures were V-shaped,Y-shaped,inverted L-shaped,or complicated dendritic networks composed of multiple V shapes.The hyacinth treatment was characterized by the greatest burrow volume,length,depth,and structural complexity,but the opening size was reduced by dense root mat coverage.Burrows in the water lettuce treatment were characterized by intermediate volume,length,branches and sinuosity,but they had the largest opening and pit size.The control treatment had a flat bottom with the smallest,shortest burrows.This study indicates that free-floating plants improve habitat suitability and change burrow morphology and may be used to improve loach breeding methods。
