Designing a heterogeneous interface to improve the kinetics of electrocatalysts represents an effective yet challenging approach for enhancing the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Herei...Designing a heterogeneous interface to improve the kinetics of electrocatalysts represents an effective yet challenging approach for enhancing the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Herein,a simple MOF-assisted etching-pyrolysis strategy is proposed to fabricate an advanced Mott-Schottky(M–S)electrocatalyst composed of Co/CeO_(2)hetero-nanoparticles embedded within N-doped hollow carbon nanoboxes(H-Co/CeO_(2)@NCBs).Notably,the interfacial Co–O–Ce bond bridging productively facilitates the electron transfer and modulates the charge distribution of the active center,thereby contributing to the ORR/OER kinetics.As expected,the optimal M–S H-Co/CeO_(2)@NCBs catalyst exhibits promising bifunctional electrocatalytic activity with a small potential discrepancy of 0.65 V.Theoretical calculations reveal that the built-in electric field in the M–S heterojunction promotes electron transfer in oxygen electrocatalysis and the interfacial bridge-induced electron redistribution optimizes the adsorption/desorption of the oxygen intermediates,leading to reduced activation energy for the bifunctional ORR/OER reactions.Importantly,H-Co/CeO_(2)@NCBs-assembled Zn-air battery(ZAB)delivers high power density(179.8 mW cm^(−2))and long-term stability(400 h).Furthermore,the assembled flexible solid-state ZAB with H-Co/CeO_(2)@NCBs cathode also exhibits excellent charge–discharge reversibility and flexibility at various bending angles.This work provides a novel perspective on developing efficient and stable M–S bifunctional oxygen electrocatalysts.展开更多
The electron configuration of the active sites can be effectively modulated by regulating the inherent nanostructure of the electrocatalysts,thereby enhancing their electrocatalytic performance.To tackle the unexplore...The electron configuration of the active sites can be effectively modulated by regulating the inherent nanostructure of the electrocatalysts,thereby enhancing their electrocatalytic performance.To tackle the unexplored challenge of substantial electrochemical overpotential,surface reconstruction has emerged as a necessary strategy.Focusing on key aspects such as Janus structures,overflow effects,the d-band center displacement hypothesis,and interface coupling related to electrochemical reactions is essential for water electrolysis.Emerging as frontrunners among next-generation electrocatalysts,Mott-Schottky(M-S)catalysts feature a heterojunction formed between a metal and a semiconductor,offering customizable and predictable interfacial synergy.This review offers an in-depth examination of the processes driving the hydrogen and oxygen evolution reactions(HER and OER),highlighting the benefits of employing nanoscale transition metal nitrides,carbides,oxides,and phosphides in M-S heterointerface catalysts.Furthermore,the challenges,limitations,and future prospects of employing M-S heterostructured catalysts for water splitting are thoroughly discussed.展开更多
Levering the local electron density allows for varying the adsorption and/or desorption feature of catalysts,enabling to boost the reaction kinetics.Mott-Schottky barrier,in which it processes different Fermi levels,f...Levering the local electron density allows for varying the adsorption and/or desorption feature of catalysts,enabling to boost the reaction kinetics.Mott-Schottky barrier,in which it processes different Fermi levels,favors the electron transport at the interface.Here,a Mo-doped CoN is coupled with NiFe-LDH for constructing a Mott-Schottky heterojunction,addressing enhanced hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and urea oxidation reaction(UOR)compared with the individual counterparts.The incorporation of high-valence Mo species and the formation of heterostructures significantly improve the corrosion resistance and electrocatalytic performance of Mo-CoN@NiFeLDH,requiring only 76 mV overpotential for HER and 257 mV for OER to achieve a high current density of 100 mA cm^(-2)in 1 M KOH.The advanced nature of our as-prepared Mott-Schottky heterojunction could be further evidenced by its robust nature of a configured alkaline electrolyzer for stable working over666 h at 200 mA cm^(-2).Impressively,only 1.692 V of cell voltage is required to yield a current density of 300 mA cm^(-2)over the as-prepared urea electrolyzer.This strategy for va rying the local electron density via construction of Mott-Schottky barrier could be regarded as a promising routine to achieve low-energy consumption green hydrogen generation.展开更多
The regulation of the interfacial electric field plays a pivotal role in magnifying the electromagnetic en-ergy attenuation capability during the design and synthesis of efficient and tunable absorbers for elec-tromag...The regulation of the interfacial electric field plays a pivotal role in magnifying the electromagnetic en-ergy attenuation capability during the design and synthesis of efficient and tunable absorbers for elec-tromagnetic waves(EMW).Herein,a rational and universally applicable two-step hydrothermal method strategy was proposed to effectively control the electronic structure of Mott-Schottky EMW absorbing materials derived from Co-MOF.The as-synthesized Co_(3)S_(4)@MoS_(2)/NC ensures efficient electron transfer,while the change redistribution leads to the emergence of additional electric dipoles under an external EMM field.In addition,the hierarchical Co_(3)S_(4)@MoS_(2)/NC nano-architecture with a hierarchical arrange-ment in 2D and 3D offers more polarization sites,thereby extending the path for EMW transmission through multiple reflections and scattering.The potential to enhance the EMW absorption performance of Co_(3)S_(4)@MoS_(2)/NC lies in its unique microstructure and substantial surface area,which optimize impedance matching properties through a synergistic effect of dipole and interfacial polarization induced by Mott-Schottky heterointerfaces.As anticipated,the Co_(3)S_(4)@MoS_(2)/NC exhibits a maximum EMW absorption ca-pacity with an RLmin value of-41.97 dB and a broad EAB of 4.24 GHz at a thickness of 2.0 mm.This study provides insights for designing highly efficient Mott-Schottky EMW absorbing materials at the molecular level rationally.展开更多
Plant species diversity is one of the most widely used indicators in ecosystem management.The relation of species diversity with the size of the sample plot has not been fully determined for Oriental beech forests(Fag...Plant species diversity is one of the most widely used indicators in ecosystem management.The relation of species diversity with the size of the sample plot has not been fully determined for Oriental beech forests(Fagus orientalis Lipsky),a widespread species in the Hyrcanian region.Assessing the impacts of plot size on species diversity is fundamental for an ecosystem-based approach to forest management.This study determined the relation of species diversity and plot size by investigating species richness and abundance of both canopy and forest floor.Two hundred and fifty-six sample plots of 625 m^(2) each were layout in a grid pattern across 16 ha.Base plots(25 m×25 m)were integrated in different scales to investigate the effect of plot size on species diversity.The total included nine plots of 0.063,0.125,0.188,0.250,0.375,0.500,0.563,0.750 and 1 ha.Ten biodiversity indices were calculated.The results show that species richness in the different plot sizes was less than the actual value.The estimated value of the Simpson species diversity index was not significantly different from actual values for both canopy and forest floor diversity.The coefficient of variation of this index for the 1-ha sample plot showed the lowest amount across different plot sizes.Inverse Hill species diversity was insignificant difference across different plot sizes with an area greater than 0.500 ha.The modified Hill evenness index for the 1-ha sample size was a correct estimation of the 16-ha for both canopy and forest floor;however,the precision estimation was higher for the canopy layer.All plots greater than 0.250-ha provided an accurate estimation of the Camargo evenness index for forest floor species,but was inaccurate across different plot sizes for the canopy layer.The results indicate that the same plot size did not have the same effect across species diversity measurements.Our results show that correct estimation of species diversity measurements is related to the selection of appropriate indicators and plot size to increase the accuracy of the estimate so that the cost and time of biodiversity management may be reduced.展开更多
Moldy core is a serious internal defect in pears.Since there is no significant difference in appearance between the healthy pears and those with mild moldy core,it is still a great challenge for the early detection of...Moldy core is a serious internal defect in pears.Since there is no significant difference in appearance between the healthy pears and those with mild moldy core,it is still a great challenge for the early detection of moldy pear core.This study transformed the vibration acoustic signals(VA signal)of pears into recurrence plots and Markov transition field to enable image-based classification of moldy cores.In addition to traditional machine-learning baselines(Random Forest and k-Nearest Neighbors)trained on LBP-extracted texture features from RP/MTF,the deep models were constructed and compared,which include ResNet-101,DenseNet-121,SqueezeNet,Vision Transformer(ViT),and an improved SqueezeNet(ISqueezeNet).Hyperparameters were tuned via Bayesian optimization over optimizer type,learning rate,batch size,and L2 weight decay,yielding model-specific optimal settings.Under these configurations,the ISqueezeNet achieved the highest test accuracy of 93.05%,with class-wise accuracies of 89.28%(healthy),96.15%(slight),and 94.44%(moderate and severe).Comparisons with lightweight networks(MobileNetV1 and ShuffleNetV2)further showed that ISqueezeNet attains superior accuracy with favorable parameter efficiency and inference speed.Grad-CAM visualizations confirmed that the model focuses on lesionrelevant regions,supporting interpretability and practical reliability.These results indicate that the proposed approach is promising for early,nondestructive detection of moldy pear cores.展开更多
Lithium-sulfur batteries(LSBs)offer high energy density and low cost but face challenges such as low sulfur utilization,lithium polysulfides(LiPSs)shuttling,and limited reaction kinetics.To address these issues,we rat...Lithium-sulfur batteries(LSBs)offer high energy density and low cost but face challenges such as low sulfur utilization,lithium polysulfides(LiPSs)shuttling,and limited reaction kinetics.To address these issues,we rationally design a Ti_(3)C_(2)T_(x)/SnS Mott-Schottky heterostructure with a built-in electric field.This three-dimensional(3D)porous architecture can enhance sulfur loading,facilitate electrolyte penetration,and expose more adsorption and catalytic sites.More importantly,the built-in electric field facilitates charge transfer and directs LiPSs migration from SnS to Ti_(3)C_(2)T_(x).The oriented migration of LiPSs enables rapid catalytic conversion at the Ti_(3)C_(2)T_(x)/SnS heterogeneous interface,enhancing electrocatalytic activity and sulfur reduction reaction kinetics.The Ti_(3)C_(2)T_(x)/SnS/S cathode achieves a high initial capacity(1367.1 mAh g^(-1)),excellent rate performance(602.7 mAh g^(-1)at 3 C),and stable long cycling performance with an average capacity decay rate of only 0.029%per cycle at 2 C.Additionally,a high-sulfur-loaded 3 Dprinted cathode with loading of 12.7 mg cm^(-2)manufactured using 3D printing exhibits an areal capacity of 15.0 mAh cm^(-2),retaining 8.9 mAh cm^(-2)after 70 cycles.展开更多
Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tre...Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tree biomass within a fully censused 20 ha forest plot in a temperate forest of northern Alabama,USA.We evaluated the relationship between biomass and topography using ridge and valley landforms along with digitally derived moisture and solar radiation indices.Every live woody stem over 1 cm diameter at breast height within this plot was mapped,measured,and identified to species in 2019-2022,and diameter data were used along with speciesspecific wood density to map the aboveground biomass at the scale of 20 m×20 m quadrats.The aboveground tree biomass was 211 Mg·ha^(-1).Other than small stream areas that experienced recent natural disturbances,the total stand biomass was not associated with landform or topographic indices.Dominant species,in contrast,had strong associations with topography.American beech(Fagus grandifolia)and yellow-poplar(Liriodendron tulipfera)dominated the valley landform,with 37% and 54% greater biomass in the valley than their plot average,respectively.Three other dominant species,white oak(Quercus alba),southern shagbark hickory(Carya carolinaeseptentrionalis),and white ash(Fraxinus americana),were more abundant on slopes and benches,thus partitioning the site.Of the six dominant species,only sugar maple(Acer saccharum)was not associated with landform.Moreover,both topographic wetness and potential radiation indices were significant predictors of dominant species biomass within each of the landforms.The study highlights the need to consider species when examining forest productivity in a range of site conditions.展开更多
基金supported by the National Natural Science Foundation of China(U24A20550,52273264 and 52470073)the Key Project of the Heilongjiang Provincial Natural Science Foundation(ZD2024B001)Outstanding Youth Fund of Heilongjiang Province(JQ2022E005).
文摘Designing a heterogeneous interface to improve the kinetics of electrocatalysts represents an effective yet challenging approach for enhancing the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Herein,a simple MOF-assisted etching-pyrolysis strategy is proposed to fabricate an advanced Mott-Schottky(M–S)electrocatalyst composed of Co/CeO_(2)hetero-nanoparticles embedded within N-doped hollow carbon nanoboxes(H-Co/CeO_(2)@NCBs).Notably,the interfacial Co–O–Ce bond bridging productively facilitates the electron transfer and modulates the charge distribution of the active center,thereby contributing to the ORR/OER kinetics.As expected,the optimal M–S H-Co/CeO_(2)@NCBs catalyst exhibits promising bifunctional electrocatalytic activity with a small potential discrepancy of 0.65 V.Theoretical calculations reveal that the built-in electric field in the M–S heterojunction promotes electron transfer in oxygen electrocatalysis and the interfacial bridge-induced electron redistribution optimizes the adsorption/desorption of the oxygen intermediates,leading to reduced activation energy for the bifunctional ORR/OER reactions.Importantly,H-Co/CeO_(2)@NCBs-assembled Zn-air battery(ZAB)delivers high power density(179.8 mW cm^(−2))and long-term stability(400 h).Furthermore,the assembled flexible solid-state ZAB with H-Co/CeO_(2)@NCBs cathode also exhibits excellent charge–discharge reversibility and flexibility at various bending angles.This work provides a novel perspective on developing efficient and stable M–S bifunctional oxygen electrocatalysts.
基金supported by the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2021L574)the Guizhou Provincial Science and Technology Foundation([2024]ZK General 425 and 438)+1 种基金the National Natural Science Foundation of China(22309033)the Academic Young Talent Foundation of Guizhou Normal University([2022]B05 and B06)。
文摘The electron configuration of the active sites can be effectively modulated by regulating the inherent nanostructure of the electrocatalysts,thereby enhancing their electrocatalytic performance.To tackle the unexplored challenge of substantial electrochemical overpotential,surface reconstruction has emerged as a necessary strategy.Focusing on key aspects such as Janus structures,overflow effects,the d-band center displacement hypothesis,and interface coupling related to electrochemical reactions is essential for water electrolysis.Emerging as frontrunners among next-generation electrocatalysts,Mott-Schottky(M-S)catalysts feature a heterojunction formed between a metal and a semiconductor,offering customizable and predictable interfacial synergy.This review offers an in-depth examination of the processes driving the hydrogen and oxygen evolution reactions(HER and OER),highlighting the benefits of employing nanoscale transition metal nitrides,carbides,oxides,and phosphides in M-S heterointerface catalysts.Furthermore,the challenges,limitations,and future prospects of employing M-S heterostructured catalysts for water splitting are thoroughly discussed.
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFB3807201)the National Natural Science Foundation of China(Grants Nos.52462035+6 种基金52272202W242102712464010)the Bituan Science and Technology Program(Grants No.2022DB009)project supported by the Jiangxi Provincial Natural Science Foundation(Grants No.20242BAB21002)the Project of Science and Technology Innovation and Entrepreneurship Fund of China Coal Technology&Engineering Group Co.,Ltd.(2022-MS0022023-TDMS007)。
文摘Levering the local electron density allows for varying the adsorption and/or desorption feature of catalysts,enabling to boost the reaction kinetics.Mott-Schottky barrier,in which it processes different Fermi levels,favors the electron transport at the interface.Here,a Mo-doped CoN is coupled with NiFe-LDH for constructing a Mott-Schottky heterojunction,addressing enhanced hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and urea oxidation reaction(UOR)compared with the individual counterparts.The incorporation of high-valence Mo species and the formation of heterostructures significantly improve the corrosion resistance and electrocatalytic performance of Mo-CoN@NiFeLDH,requiring only 76 mV overpotential for HER and 257 mV for OER to achieve a high current density of 100 mA cm^(-2)in 1 M KOH.The advanced nature of our as-prepared Mott-Schottky heterojunction could be further evidenced by its robust nature of a configured alkaline electrolyzer for stable working over666 h at 200 mA cm^(-2).Impressively,only 1.692 V of cell voltage is required to yield a current density of 300 mA cm^(-2)over the as-prepared urea electrolyzer.This strategy for va rying the local electron density via construction of Mott-Schottky barrier could be regarded as a promising routine to achieve low-energy consumption green hydrogen generation.
基金supported by the National Natural Science Foundation of China(Nos.22271178,22301239)Science and Technology New Star in Shaanxi Province(No.2023KJXX-045)+3 种基金the Youth Talent Promotion Project of Science and Technology Association of Universities of Shaanxi Province(No.20240601)Shaanxi Provincial Department of Education service local special project,industrialization cultivation project(No.23JC007)the Research Program of the Shaanxi Provincial Department of Education(Nos.23JK0596,23JP135)the Open Foundation of Xi’an Key Laboratory of Functional Supramolecular Structure and Materials(No.CFZKFKT23003).
文摘The regulation of the interfacial electric field plays a pivotal role in magnifying the electromagnetic en-ergy attenuation capability during the design and synthesis of efficient and tunable absorbers for elec-tromagnetic waves(EMW).Herein,a rational and universally applicable two-step hydrothermal method strategy was proposed to effectively control the electronic structure of Mott-Schottky EMW absorbing materials derived from Co-MOF.The as-synthesized Co_(3)S_(4)@MoS_(2)/NC ensures efficient electron transfer,while the change redistribution leads to the emergence of additional electric dipoles under an external EMM field.In addition,the hierarchical Co_(3)S_(4)@MoS_(2)/NC nano-architecture with a hierarchical arrange-ment in 2D and 3D offers more polarization sites,thereby extending the path for EMW transmission through multiple reflections and scattering.The potential to enhance the EMW absorption performance of Co_(3)S_(4)@MoS_(2)/NC lies in its unique microstructure and substantial surface area,which optimize impedance matching properties through a synergistic effect of dipole and interfacial polarization induced by Mott-Schottky heterointerfaces.As anticipated,the Co_(3)S_(4)@MoS_(2)/NC exhibits a maximum EMW absorption ca-pacity with an RLmin value of-41.97 dB and a broad EAB of 4.24 GHz at a thickness of 2.0 mm.This study provides insights for designing highly efficient Mott-Schottky EMW absorbing materials at the molecular level rationally.
基金funded by Gorgan University of Agricultural Sciences and Natural Resources(grant number 9318124503).
文摘Plant species diversity is one of the most widely used indicators in ecosystem management.The relation of species diversity with the size of the sample plot has not been fully determined for Oriental beech forests(Fagus orientalis Lipsky),a widespread species in the Hyrcanian region.Assessing the impacts of plot size on species diversity is fundamental for an ecosystem-based approach to forest management.This study determined the relation of species diversity and plot size by investigating species richness and abundance of both canopy and forest floor.Two hundred and fifty-six sample plots of 625 m^(2) each were layout in a grid pattern across 16 ha.Base plots(25 m×25 m)were integrated in different scales to investigate the effect of plot size on species diversity.The total included nine plots of 0.063,0.125,0.188,0.250,0.375,0.500,0.563,0.750 and 1 ha.Ten biodiversity indices were calculated.The results show that species richness in the different plot sizes was less than the actual value.The estimated value of the Simpson species diversity index was not significantly different from actual values for both canopy and forest floor diversity.The coefficient of variation of this index for the 1-ha sample plot showed the lowest amount across different plot sizes.Inverse Hill species diversity was insignificant difference across different plot sizes with an area greater than 0.500 ha.The modified Hill evenness index for the 1-ha sample size was a correct estimation of the 16-ha for both canopy and forest floor;however,the precision estimation was higher for the canopy layer.All plots greater than 0.250-ha provided an accurate estimation of the Camargo evenness index for forest floor species,but was inaccurate across different plot sizes for the canopy layer.The results indicate that the same plot size did not have the same effect across species diversity measurements.Our results show that correct estimation of species diversity measurements is related to the selection of appropriate indicators and plot size to increase the accuracy of the estimate so that the cost and time of biodiversity management may be reduced.
基金Key R&D Projects in Shandong Province(Grant No.2022TZXD007)PhD Start-up Fund of University of Jinan(Grant No.XBS2494).
文摘Moldy core is a serious internal defect in pears.Since there is no significant difference in appearance between the healthy pears and those with mild moldy core,it is still a great challenge for the early detection of moldy pear core.This study transformed the vibration acoustic signals(VA signal)of pears into recurrence plots and Markov transition field to enable image-based classification of moldy cores.In addition to traditional machine-learning baselines(Random Forest and k-Nearest Neighbors)trained on LBP-extracted texture features from RP/MTF,the deep models were constructed and compared,which include ResNet-101,DenseNet-121,SqueezeNet,Vision Transformer(ViT),and an improved SqueezeNet(ISqueezeNet).Hyperparameters were tuned via Bayesian optimization over optimizer type,learning rate,batch size,and L2 weight decay,yielding model-specific optimal settings.Under these configurations,the ISqueezeNet achieved the highest test accuracy of 93.05%,with class-wise accuracies of 89.28%(healthy),96.15%(slight),and 94.44%(moderate and severe).Comparisons with lightweight networks(MobileNetV1 and ShuffleNetV2)further showed that ISqueezeNet attains superior accuracy with favorable parameter efficiency and inference speed.Grad-CAM visualizations confirmed that the model focuses on lesionrelevant regions,supporting interpretability and practical reliability.These results indicate that the proposed approach is promising for early,nondestructive detection of moldy pear cores.
基金the financial support from the National Natural Science Foundation of China(52203340)the Guangdong Basic and Applied Basic Research Foundation(2025A1515012287)+1 种基金the Natural Science Foundation of Hubei Province(Joint Fund,2025AFD334)the Hubei Key Laboratory of Energy Storage and Power Battery(Hubei University of Automotive Technology,ZDK22024B06)。
文摘Lithium-sulfur batteries(LSBs)offer high energy density and low cost but face challenges such as low sulfur utilization,lithium polysulfides(LiPSs)shuttling,and limited reaction kinetics.To address these issues,we rationally design a Ti_(3)C_(2)T_(x)/SnS Mott-Schottky heterostructure with a built-in electric field.This three-dimensional(3D)porous architecture can enhance sulfur loading,facilitate electrolyte penetration,and expose more adsorption and catalytic sites.More importantly,the built-in electric field facilitates charge transfer and directs LiPSs migration from SnS to Ti_(3)C_(2)T_(x).The oriented migration of LiPSs enables rapid catalytic conversion at the Ti_(3)C_(2)T_(x)/SnS heterogeneous interface,enhancing electrocatalytic activity and sulfur reduction reaction kinetics.The Ti_(3)C_(2)T_(x)/SnS/S cathode achieves a high initial capacity(1367.1 mAh g^(-1)),excellent rate performance(602.7 mAh g^(-1)at 3 C),and stable long cycling performance with an average capacity decay rate of only 0.029%per cycle at 2 C.Additionally,a high-sulfur-loaded 3 Dprinted cathode with loading of 12.7 mg cm^(-2)manufactured using 3D printing exhibits an areal capacity of 15.0 mAh cm^(-2),retaining 8.9 mAh cm^(-2)after 70 cycles.
基金supported in part by the intramural research program of the US Department of Agriculture,National Institute of Food and Agriculture,Evans-Allen#1024525,and Capacity Building Grant#006531supported in part by the US National Science Foundation RII Track 2 FEC:Leveraging Intelligent Informatics and Smart Data for Improved Understanding of Northern Forest Ecosystem Resiliency(INSPIRES)#1920908by The Lyndhurst Foundation.
文摘Understanding local variation in forest biomass allows for a better evaluation of broad-scale patterns and interpretation of forest ecosystems’role in carbon dynamics.This study focuses on patterns of aboveground tree biomass within a fully censused 20 ha forest plot in a temperate forest of northern Alabama,USA.We evaluated the relationship between biomass and topography using ridge and valley landforms along with digitally derived moisture and solar radiation indices.Every live woody stem over 1 cm diameter at breast height within this plot was mapped,measured,and identified to species in 2019-2022,and diameter data were used along with speciesspecific wood density to map the aboveground biomass at the scale of 20 m×20 m quadrats.The aboveground tree biomass was 211 Mg·ha^(-1).Other than small stream areas that experienced recent natural disturbances,the total stand biomass was not associated with landform or topographic indices.Dominant species,in contrast,had strong associations with topography.American beech(Fagus grandifolia)and yellow-poplar(Liriodendron tulipfera)dominated the valley landform,with 37% and 54% greater biomass in the valley than their plot average,respectively.Three other dominant species,white oak(Quercus alba),southern shagbark hickory(Carya carolinaeseptentrionalis),and white ash(Fraxinus americana),were more abundant on slopes and benches,thus partitioning the site.Of the six dominant species,only sugar maple(Acer saccharum)was not associated with landform.Moreover,both topographic wetness and potential radiation indices were significant predictors of dominant species biomass within each of the landforms.The study highlights the need to consider species when examining forest productivity in a range of site conditions.
