Root pullout performance of plants is an important mechanical basis for soil reinforcement by plant roots in the semi-arid areas.Studies have shown that it is affected by plant factors(species,ages,root geometry,etc.)...Root pullout performance of plants is an important mechanical basis for soil reinforcement by plant roots in the semi-arid areas.Studies have shown that it is affected by plant factors(species,ages,root geometry,etc.)and soil factors(soil types,soil moisture,soil bulk densities,etc.).However,the effects of loading rates on root pullout performance are not well studied.To explore the mechanical interactions under different loading rates,we conducted pullout tests on Medicago sativa L.and Hippophae rhamnoides L.roots under five loading rates,i.e.,5,50,100,150,and 200 mm/min.In addition,tensile tests were conducted on the roots in diameters of 0.5-2.0 mm to compare the relationship between root tensile properties and root pullout properties.Results showed that two root failure modes,slippage and breakage,were observed during root pullout tests.All M.sativa roots were pulled out,while 72.2%of H.rhamnoides roots were broken.The maximum fracture diameter and fracture root length of H.rhamnoides were 1.22 mm and 7.44 cm under 100 mm/min loading rate,respectively.Root displacement values were 4.63%(±0.43%)and 8.91%(±0.52%)of the total root length for M.sativa and H.rhamnoides,respectively.The values of maximum pullout force were 14.6(±0.7)and 17.7(±1.8)N under 100 mm/min for M.sativa and H.rhamnoides,respectively.Values of the maximum pullout strength for M.sativa and H.rhamnoides were 38.38(±5.48)MPa under 150 mm/min and 12.47(±1.43)MPa under 100 mm/min,respectively.Root-soil friction coefficient under 100 mm/min was significantly larger than those under other loading rates for both the two species.Values of the maximum root pullout energy for M.sativa and H.rhamnoides were 87.83(±21.55)mm•N under 100 mm/min and 173.53(±38.53)mm•N under 200 mm/min,respectively.Root pullout force was significantly related to root diameter(P<0.01).Peak root pullout force was significantly affected by loading rates when the effect of root diameter was included(P<0.01),and vice versa.Except for the failure mode and peak pullout force,other pullout parameters,including root pullout strength,root displacement,root-soil friction coefficient,and root pullout energy were not significantly affected by loading rates(P>0.05).Root pullout strength was greater than root tensile strength for the two species.The results suggested that there was no need to deliberately control loading rate in root pullout tests in the semi-arid soil,and root pullout force and pullout strength could be better parameters for root reinforcement model compared with root tensile strength as root pullout force and pullout strength could more realistically reflect the working state of roots in the semi-arid soil.展开更多
The litterbag method was used to study the decomposition of wetland plant root in three wetlands along a water level gradient in the Sanjiang Plain,Northeast China.These wetlands are Calamagrostis angustifolia(C.aa),C...The litterbag method was used to study the decomposition of wetland plant root in three wetlands along a water level gradient in the Sanjiang Plain,Northeast China.These wetlands are Calamagrostis angustifolia(C.aa),Carex meyeriana(C.ma)and Carex lasiocarpa (C.la).The objective of our study is to evaluate the influence of environment and substrate quality on decomposition rates in the three wetlands.Calico material was used as a standard substrate to evaluate environmental influences.Roots native to each we...展开更多
Background:Metabolic scaling theory predicts that plant productivity and biomass are both size-dependent.However,this theory has not yet been tested in plant roots.Methods:In this study,we tested how metabolic scaling...Background:Metabolic scaling theory predicts that plant productivity and biomass are both size-dependent.However,this theory has not yet been tested in plant roots.Methods:In this study,we tested how metabolic scaling occurs in plants using a comprehensive plant root dataset made up of 1016 observations from natural habitats.We generated metabolic scaling exponents by logtransformation of root productivity versus biomass.Results:Results showed that the metabolic scaling exponents of fine root(<2mm in diameter)productivity versus biomass were close to 1.0 for all ecosystem types and functional groups.Scaling exponents decreased in coarse roots(>2mm in diameter).Conclusions:We found isometric metabolic scaling in fine roots,a metabolically active organ similar to seedlings or saplings.Our findings also indicate a shift in metabolic scaling during plant development.Overall,our study supports the absence of any unified single constant scaling exponent for metabolism-biomass relationships in terrestrial plants,especially for forests with woody species.展开更多
Technological and economic opportunities,alongside the apparent ecological benefits,point to biodesign as a new industrial paradigm for the fabrication of products in the twenty-first century.The presented work studie...Technological and economic opportunities,alongside the apparent ecological benefits,point to biodesign as a new industrial paradigm for the fabrication of products in the twenty-first century.The presented work studies plant roots as a biodesign material in the fabrication of self-supported 3D structures,where the biologically and digitally designed materials provide each other with structural stability.Taking a material-driven design approach,we present our systematic tinkering activities with plant roots to better understand and anticipate their responsive behaviour.These helped us to identify the key design parameters and advance the unique potential of plant roots to bind discrete porous structures.We illustrate this binding potential of plant roots with a hybrid 3D object,for which plant roots connect 600 computationally designed,optimized,and fabricated bioplastic beads into a low stool.展开更多
Objective\ To validate the use of Allium sativum as a reliable test model for genotoxicity, isoproturon, a substituted phenylalkylurea herbicide, was evaluated on the root meristem cells by this plant system. M...Objective\ To validate the use of Allium sativum as a reliable test model for genotoxicity, isoproturon, a substituted phenylalkylurea herbicide, was evaluated on the root meristem cells by this plant system. Method\ Test concentrations were selected by determining EC50 and root tips were exposed to various concentrations for 6 or 24 hr. EC50 concentration was calculated to be 70.8 ppm for the root growth. In addition to root growth retardation exposure to isoproturon induced morpholoogical changes like discolouration and stiffness of roots. Results\ Exposure to various experimental concentrations of isoproturon (35-280 ppm), including EC50, significantly and dose-dependently inhibited the mitotic index and induced chromosome breaks/mitotic aberrations at 6 or 24 hr. Conclusion\ The frequency of aberrations was found to be decreased in a dose dependant manner at 24 or 48 hr post exposure, however in comparison of control cells the frequency of aberrations was considerably high which indicates genotoxicity potentials of isoproturon. Further, present study also suggests that Allium sativum is a sensitive, efficient, and reliable test system for measuring the genotoxicity potential of environmental chemicals.展开更多
Soil degradation threatens the forest sustainable productivity,particularly in afforestation system.Biochar derived from agroforestry waste or biomass can potentially improve the degraded forest soil and promote the t...Soil degradation threatens the forest sustainable productivity,particularly in afforestation system.Biochar derived from agroforestry waste or biomass can potentially improve the degraded forest soil and promote the tree growth.To expand the application of biochar for forestry productivity improvement,we here reviewed the effects and the underlying mechanisms of biochar on the degraded forest soil and tree growth.Totally 96 studies that conducted from pot to field investigations in China were summarized.The result suggested that biochar generally exerted positive effects on restoration of degraded forest soil such as that with compaction,acidification or soil erosion,which are mainly manifested by improving soil porosity,increasing pH,enhancing erosion resistance and mitigating greenhouse gas emissions.Furthermore,biochar incorporation promoted the growth of tested trees in most cases,which effect was mainly attributing to directly supplying nutrients,improving soil physio-chemical properties,enhancing the root’s nutrient absorption capacity,and enlarging the living space.In summary,current studies demonstrate that biochar has a unique potential for improving degraded forest soils and promoting tree growth.However,investigations on the underlying mechanisms and the long-term effects should be strengthened.展开更多
Plants are usually considered static organisms,but they can perform a wide range of movements that can be a source of inspiration for robots.The roots’growing motion is the most noteworthy since they are excellent di...Plants are usually considered static organisms,but they can perform a wide range of movements that can be a source of inspiration for robots.The roots’growing motion is the most noteworthy since they are excellent diggers that can move in unstructured environments and navigate past barriers.Furthermore,root growth has a high energy efficiency since it penetrates the soil at its tip,adding new material without displacing the already grown portion,minimizing the energy dissipation due to friction and lowering the inertia.A robot inspired by the growth of roots could be used in search and rescue or environmental monitoring.The design of a soft robot inspired by root growth is presented in this article.The robot body consists of a cylindrical plastic membrane folded inside itself.The robot body is inflated,and its tip is everted,expanding its length as air is blown from the base.Velcro straps are placed on the membrane’s exterior surface to keep it folded.The head is positioned inside the tip,which houses the mechanism that controls the growth direction.It consists of housing for two balloons that are selectively inflated,and their expansion applies pressure on the exterior surface,opening the Velcro straps and determining the growth direction.The robot was constructed,and a kinematic model of its motion in the plane was created and compared with experimental data.The error in predicting the turning angle is only 5%,and the resulting predicted position differs on average by 55 mm on a total length of 850 mm.展开更多
基金supported by the Natural Science Foundation of Shanxi Province of China(20210302123105)the Shanxi Scholarship Council of China(2020-054)the Changjiang River Scientific Research Institute(CRSRI)Open Research Program(CKWV20221006/KY).
文摘Root pullout performance of plants is an important mechanical basis for soil reinforcement by plant roots in the semi-arid areas.Studies have shown that it is affected by plant factors(species,ages,root geometry,etc.)and soil factors(soil types,soil moisture,soil bulk densities,etc.).However,the effects of loading rates on root pullout performance are not well studied.To explore the mechanical interactions under different loading rates,we conducted pullout tests on Medicago sativa L.and Hippophae rhamnoides L.roots under five loading rates,i.e.,5,50,100,150,and 200 mm/min.In addition,tensile tests were conducted on the roots in diameters of 0.5-2.0 mm to compare the relationship between root tensile properties and root pullout properties.Results showed that two root failure modes,slippage and breakage,were observed during root pullout tests.All M.sativa roots were pulled out,while 72.2%of H.rhamnoides roots were broken.The maximum fracture diameter and fracture root length of H.rhamnoides were 1.22 mm and 7.44 cm under 100 mm/min loading rate,respectively.Root displacement values were 4.63%(±0.43%)and 8.91%(±0.52%)of the total root length for M.sativa and H.rhamnoides,respectively.The values of maximum pullout force were 14.6(±0.7)and 17.7(±1.8)N under 100 mm/min for M.sativa and H.rhamnoides,respectively.Values of the maximum pullout strength for M.sativa and H.rhamnoides were 38.38(±5.48)MPa under 150 mm/min and 12.47(±1.43)MPa under 100 mm/min,respectively.Root-soil friction coefficient under 100 mm/min was significantly larger than those under other loading rates for both the two species.Values of the maximum root pullout energy for M.sativa and H.rhamnoides were 87.83(±21.55)mm•N under 100 mm/min and 173.53(±38.53)mm•N under 200 mm/min,respectively.Root pullout force was significantly related to root diameter(P<0.01).Peak root pullout force was significantly affected by loading rates when the effect of root diameter was included(P<0.01),and vice versa.Except for the failure mode and peak pullout force,other pullout parameters,including root pullout strength,root displacement,root-soil friction coefficient,and root pullout energy were not significantly affected by loading rates(P>0.05).Root pullout strength was greater than root tensile strength for the two species.The results suggested that there was no need to deliberately control loading rate in root pullout tests in the semi-arid soil,and root pullout force and pullout strength could be better parameters for root reinforcement model compared with root tensile strength as root pullout force and pullout strength could more realistically reflect the working state of roots in the semi-arid soil.
基金supported by the Key Knowledge In-novation Project of Chinese Academy of Science(No.KSCX2-YW-N-46-06).
文摘The litterbag method was used to study the decomposition of wetland plant root in three wetlands along a water level gradient in the Sanjiang Plain,Northeast China.These wetlands are Calamagrostis angustifolia(C.aa),Carex meyeriana(C.ma)and Carex lasiocarpa (C.la).The objective of our study is to evaluate the influence of environment and substrate quality on decomposition rates in the three wetlands.Calico material was used as a standard substrate to evaluate environmental influences.Roots native to each we...
基金the National Key Research and Development Plan of China(2016YFA0600801)the Hundred Talents Program of Shaanxi Province(A289021701)+2 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(2018JZ3002)the Special Fund from the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau(A314021403-C9)the Double First Class University Plan of NWSUAF(Z102021829).
文摘Background:Metabolic scaling theory predicts that plant productivity and biomass are both size-dependent.However,this theory has not yet been tested in plant roots.Methods:In this study,we tested how metabolic scaling occurs in plants using a comprehensive plant root dataset made up of 1016 observations from natural habitats.We generated metabolic scaling exponents by logtransformation of root productivity versus biomass.Results:Results showed that the metabolic scaling exponents of fine root(<2mm in diameter)productivity versus biomass were close to 1.0 for all ecosystem types and functional groups.Scaling exponents decreased in coarse roots(>2mm in diameter).Conclusions:We found isometric metabolic scaling in fine roots,a metabolically active organ similar to seedlings or saplings.Our findings also indicate a shift in metabolic scaling during plant development.Overall,our study supports the absence of any unified single constant scaling exponent for metabolism-biomass relationships in terrestrial plants,especially for forests with woody species.
文摘Technological and economic opportunities,alongside the apparent ecological benefits,point to biodesign as a new industrial paradigm for the fabrication of products in the twenty-first century.The presented work studies plant roots as a biodesign material in the fabrication of self-supported 3D structures,where the biologically and digitally designed materials provide each other with structural stability.Taking a material-driven design approach,we present our systematic tinkering activities with plant roots to better understand and anticipate their responsive behaviour.These helped us to identify the key design parameters and advance the unique potential of plant roots to bind discrete porous structures.We illustrate this binding potential of plant roots with a hybrid 3D object,for which plant roots connect 600 computationally designed,optimized,and fabricated bioplastic beads into a low stool.
文摘Objective\ To validate the use of Allium sativum as a reliable test model for genotoxicity, isoproturon, a substituted phenylalkylurea herbicide, was evaluated on the root meristem cells by this plant system. Method\ Test concentrations were selected by determining EC50 and root tips were exposed to various concentrations for 6 or 24 hr. EC50 concentration was calculated to be 70.8 ppm for the root growth. In addition to root growth retardation exposure to isoproturon induced morpholoogical changes like discolouration and stiffness of roots. Results\ Exposure to various experimental concentrations of isoproturon (35-280 ppm), including EC50, significantly and dose-dependently inhibited the mitotic index and induced chromosome breaks/mitotic aberrations at 6 or 24 hr. Conclusion\ The frequency of aberrations was found to be decreased in a dose dependant manner at 24 or 48 hr post exposure, however in comparison of control cells the frequency of aberrations was considerably high which indicates genotoxicity potentials of isoproturon. Further, present study also suggests that Allium sativum is a sensitive, efficient, and reliable test system for measuring the genotoxicity potential of environmental chemicals.
基金the College Students’Innovation and Entrepreneurship Training Program of Jiangsu Province(202010298026Z)the National Natural Science Foundation of China(31972518)the National Key Research and Development Program of China(2017YFC0505502).
文摘Soil degradation threatens the forest sustainable productivity,particularly in afforestation system.Biochar derived from agroforestry waste or biomass can potentially improve the degraded forest soil and promote the tree growth.To expand the application of biochar for forestry productivity improvement,we here reviewed the effects and the underlying mechanisms of biochar on the degraded forest soil and tree growth.Totally 96 studies that conducted from pot to field investigations in China were summarized.The result suggested that biochar generally exerted positive effects on restoration of degraded forest soil such as that with compaction,acidification or soil erosion,which are mainly manifested by improving soil porosity,increasing pH,enhancing erosion resistance and mitigating greenhouse gas emissions.Furthermore,biochar incorporation promoted the growth of tested trees in most cases,which effect was mainly attributing to directly supplying nutrients,improving soil physio-chemical properties,enhancing the root’s nutrient absorption capacity,and enlarging the living space.In summary,current studies demonstrate that biochar has a unique potential for improving degraded forest soils and promoting tree growth.However,investigations on the underlying mechanisms and the long-term effects should be strengthened.
文摘Plants are usually considered static organisms,but they can perform a wide range of movements that can be a source of inspiration for robots.The roots’growing motion is the most noteworthy since they are excellent diggers that can move in unstructured environments and navigate past barriers.Furthermore,root growth has a high energy efficiency since it penetrates the soil at its tip,adding new material without displacing the already grown portion,minimizing the energy dissipation due to friction and lowering the inertia.A robot inspired by the growth of roots could be used in search and rescue or environmental monitoring.The design of a soft robot inspired by root growth is presented in this article.The robot body consists of a cylindrical plastic membrane folded inside itself.The robot body is inflated,and its tip is everted,expanding its length as air is blown from the base.Velcro straps are placed on the membrane’s exterior surface to keep it folded.The head is positioned inside the tip,which houses the mechanism that controls the growth direction.It consists of housing for two balloons that are selectively inflated,and their expansion applies pressure on the exterior surface,opening the Velcro straps and determining the growth direction.The robot was constructed,and a kinematic model of its motion in the plane was created and compared with experimental data.The error in predicting the turning angle is only 5%,and the resulting predicted position differs on average by 55 mm on a total length of 850 mm.
