A new family of univariate exponential slash distribution is introduced, which is based on elliptical distributions and defined by means of a stochastic representation as the scale mixture of an elliptically distribut...A new family of univariate exponential slash distribution is introduced, which is based on elliptical distributions and defined by means of a stochastic representation as the scale mixture of an elliptically distributed random variable with respect to the power of an exponential random variable. The same idea is extended to the multivariate case. General properties of the resulting families, including their moments and kurtosis coefficient, are stud- ied. And inferences based on methods of moment and maximum likelihood are discussed. A real data is presented to show this family is flexible and fits much better than other related families.展开更多
Soil organic carbon （C） and total nitrogen （N） pools of a Chinese fir （Cunninghamia lanceolata （Lamb.） Hook.） （CF） forest, and an evergreen broadleaf （EB） forest located in mid-subtropical, southeastern Ch...Soil organic carbon （C） and total nitrogen （N） pools of a Chinese fir （Cunninghamia lanceolata （Lamb.） Hook.） （CF） forest, and an evergreen broadleaf （EB） forest located in mid-subtropical, southeastern China, were compared before clearcutting, with the effect of slash burning on organic C and total N in the top 10 cm of soil before and after burning also being evaluated. Prior to clearcutting CF forest had significantly lower （P 〈0.05） organic C and total N in the soil （0-100 cm） compared to EB forest with approximately 60% of the C and N at the two forest sites stored at the 0 to 40 cm soil. In post-burn samples of the 0-10 cm depth at 5 days, 1 year, and 5 years for CF and EB forests, significantly lower levels （P 〈0.05） of organic C and total N than those in the pre-burn samples were observed. Compared to the pre-burn levels, at post-burn year 5, surface soil organic C storage was only 85% in CF forest and 72% in EB forest, while total N storage was 77% for CF forest and 73% for EB forest. Slash burning caused marked long-term changes in surface soil C and N in the two forest types.展开更多
Carbon sequestration in forests is of great interest due to concerns about global climate change.Carbon storage rates depend on ecosystem fluxes（photosynthesis and ecosystem respiration）,typically quantified as net ...Carbon sequestration in forests is of great interest due to concerns about global climate change.Carbon storage rates depend on ecosystem fluxes（photosynthesis and ecosystem respiration）,typically quantified as net ecosystem exchange（NEE）.Methods to estimate forest NEE without intensive site sampling are needed to accurately assess rates of carbon sequestration at stand-level and larger scales.We produced spatially-explicit estimates of NEE for 9 770 ha of slash pine（Pinus elliottii） plantations in North-Central Florida for a single year by coupling remote sensing-based estimates of leaf area index（LAI） with a process-based growth simulation model.LAI estimates produced from a neural-network modeling of ground plot and Landsat TM satellite data had a mean of 1.06（range 0-3.93,including forest edges）.Using the neural network LAI values as inputs,the slash pine simulation model（SPM2） estimates of NEE ranged from-5.52 to 11.06 Mg·ha^-1·a^-1with a mean of 3.47 Mg·ha^-1·a^-1Total carbon storage for the year was 33920 t,or about 3.5 tons per hectare.Both estimated LAI and NEE were highly sensitive to fertilization.展开更多
During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilize...During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilizer decreased the growth of slash pine, while P not only significantly improved the increment of bottom diameter, height and crown diameter, but also caused earlier canopy closure of the stand. It also had a sustainable effect in the next two years. Slash pine had the most significant response to the treatment of 200 kg P2O5 ha-1, in which tree height, bottom diameter and crown diameter (EW and SN) were increased by 22%, 35%, 20% and 18% in 1994, 21%, 25%, 10% and 10% in 1995, respectively, compared to the control.Although there was no remarkable response to K fertilizer, good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha-1 existed and tree height, bottom diameter and crown diameter (EW and SN)were increased by 31%, 14%, 23% and 21%, respectively, in 1993, compared to the control.展开更多
We introduce a new class of the slash distribution using the epsilon half normal distribution. The newly defined model extends the slashed half normal distribution and has more kurtosis than the ordinary half normal d...We introduce a new class of the slash distribution using the epsilon half normal distribution. The newly defined model extends the slashed half normal distribution and has more kurtosis than the ordinary half normal distribution. We study the characterization and properties including moments and some measures based on moments of this distribution. A simulation is conducted to investigate asymptotically the bias properties of the estimators for the parameters. We illustrate its use on a real data set by using maximum likelihood estimation.展开更多
The three methods of slash disposal in this experiment were no treatment, strip piling and burning. The results obtained from this study showed that the soil erosion, water and nutrient loss were higher in the logged ...The three methods of slash disposal in this experiment were no treatment, strip piling and burning. The results obtained from this study showed that the soil erosion, water and nutrient loss were higher in the logged areas by burning than in the logged areas by no treatment and strip piling. The soil and water loss was not serious when the slope degree of the logged area was less than 16o. The survival rate of planted seedlings was higher and the growth was better in the logged areas followed by burning than in the logged areas by no treatment and strip piling. Burning should not be used when the slope was more than 23o.展开更多
Slash pine(Pinus elliottii Engelm.var.elliottii)is a resin-producing species grown worldwide for significant economic benefits for wood production.Resin tapping cre-ates a carbon sink at the expense of carbon allocati...Slash pine(Pinus elliottii Engelm.var.elliottii)is a resin-producing species grown worldwide for significant economic benefits for wood production.Resin tapping cre-ates a carbon sink at the expense of carbon allocation for growth and consequently,wood production may be reduced.Non-structural carbohydrates comprising starch and sugars stored in plant organs,may serve as intermediate pools between assimilation and utilisation.However,the effect of resin tapping between tree growth and non-structural carbo-hydrates is not well understood.This study investigated(1)the effects of resin tapping on radial growth,(2)the effects of resin tapping on non-structural carbohydrate pools in different compartments,and(3)the feasibility of resin pro-duction without disruption of tree growth.Twenty one-year-old slash pines were subjected to resin tapping over two suc-cessive years.Non-structural carbohydrate concentrations in needles,branches,stem phloem,and roots of tapped and untapped trees in summer and winter were determined after the second year of resin harvest.The results showed that tapping had no significant effects on annual increments.Starch was the dominant non-structural carbohydrate frac-tion,regardless of tissues and season,and constituted up to 99%of the total non-structural carbohydrates in the phloem and roots.Glucose and fructose were the dominant sugars;sucrose was negligible.Compared with the controls,tapped trees showed 26%lower non-structural carbohydrate concen-tration in the phloem above the tapping wound in summer,which was attributable to the decreased abundance of starch,glucose,fructose,and sucrose.In winter,the altered non-structural carbohydrate profiles in the phloem above the tap-ping wounding were minimised as a result of recovery of the sugar concentrations.In contrast to free sugars,which accu-mulated substantially in needles and branches during winter,starch was enriched in the phloem,roots,and current-year needles.The results provide evidence for a localised effect of resin tapping,and highlight the observation that resin extrac-tion does not always cause a sacrifice in wood growth under a moderate resin-tapping intensity in slash pine plantations.展开更多
ZTE Corporation (ZTE), a leading global provider of telecommunications equipment and network solutions, revealed on May 6, 2008 that its award winning Broadband Universal Access System could help operators make a majo...ZTE Corporation (ZTE), a leading global provider of telecommunications equipment and network solutions, revealed on May 6, 2008 that its award winning Broadband Universal Access System could help operators make a major impact on their carbon footprint as well as save millions of dollars a year in power costs. ZTE’s DSLAM ZXDSL FSAP 9806H overreaches the European code of conduct on energy consumption for broadband equipment, offering a significant power consumption savings per port.展开更多
Slash-and-burn practices used by farmers in prior growing periods could affect soil quality, particularly topsoil properties. This study aimed to assess soil biophysical and chemical properties at different landscape ...Slash-and-burn practices used by farmers in prior growing periods could affect soil quality, particularly topsoil properties. This study aimed to assess soil biophysical and chemical properties at different landscape levels within the watershed site. Soil samples were collected by a core method in the topsoil layer in slash-and-burn sites. Field analysis was on bulk density and porosity by the gravimetric method, while laboratory analysis was done on organic matter by the Loss on Ignitions Method and other macronutrients for crops (total nitrogen, phosphorus availability, and potassium availability) followed standard analytical methods. To see if there was a significant difference between sites, DMRT 5% was used. The results of the study showed slash-and-burn practice affects soil physical properties such that high bulk density in upstream, midstream, and downstream ranged from 1.55 g/cm<sup>3</sup> to 1.71 g/cm<sup>3</sup>, 1.55 g/cm<sup>3</sup> to 1.80 g/cm<sup>3</sup>, and 1.38 g/cm<sup>3 </sup>to 1.79 g/cm<sup>3</sup> respectively. Poor porosity in upstream, midstream, and downstream ranged from 33.91% to 40.06%, 30.38% to 41.75%, and 30.91% to 46.65%, respectively. Organic matter content was low in the upstream, midstream, and downstream areas, ranging from 2.86% to 3.39%, 2.58% to 3.88%, and 2.91% to 3.88%, respectively. However, soil pH remains neutral, and nitrogen levels are low but near-optimal in the upstream and very low in the midstream and downstream. Phosphorus is extremely high upstream but very low in midstream and downstream. However, potassium remains at a low level close optimum level in the entire watershed.展开更多
Biochar production from woody biomass generated during forest management(slash)offers significant benefits for soil health and carbon emissions,yet its adoption remains limited in the western United States(U.S.).To ad...Biochar production from woody biomass generated during forest management(slash)offers significant benefits for soil health and carbon emissions,yet its adoption remains limited in the western United States(U.S.).To address this challenge,the U.S.Department of Agriculture(U.S.D.A.)Forest Service Rocky Mountain Research Station organized two workshops focused on forest management-centric biochar production.These workshops convened a diverse group of stakeholders,including investors,land management practitioners,industry professionals,and research scientists,each with unique roles in slash-based biochar production.This article presents a synthesis of the insights and perspectives gathered from these workshops,aiming to identify barriers and propose viable pathways for overcoming them.The barriers encompass governance issues such as policy and permitting,economic challenges related to costs,funding,and market stability,technological hurdles concerning methods and equipment,and a need for further research and improved science dissemination.In response to these challenges,workshop attendees collaboratively outlined specific strategies to reduce these barriers.These strategies emphasize the expansion of operational initiatives,the development of proactive policies,the stabilization of biochar markets,and the generation of additional case studies showcasing the effects of biochar amendments across various soils and environments.Collectively,the insights gleaned from this workshop series provide a comprehensive roadmap outlining both the struggles and the necessary actions and investments required to enhance the scale of slash-based biochar production and application in the western U.S.展开更多
The new shoot density of slash pine serves as a vital indicator for assessing its growth and photosynthetic capacity,while the number of new shoots offers an intuitive reflection of this density.With deep learning met...The new shoot density of slash pine serves as a vital indicator for assessing its growth and photosynthetic capacity,while the number of new shoots offers an intuitive reflection of this density.With deep learning methods becoming increasingly popular,automated counting of new shoots has greatly improved in recent years but is still limited by tedious and expensive data collection and labeling.To resolve these issues,this paper proposes a semi-supervised counting network(MTSC-Net)for estimating the number of slash pine new shoots.First,based on the mean-teacher framework,we introduce the improved VGG19 to extract multiscale new shoot features.Second,to connect local new shoot feature information with global channel features,attention feature fusion module is introduced to achieve effective feature fusion.Finally,the new shoot density map and density probability distribution are processed in a fine-grained manner through multiscale dilated convolution of the regression head and classification head.In addition,a masked image modeling strategy is introduced to encourage the contextual understanding of global new shoot features and improve the counting performance.The experimental results show that MTSC-Net outperforms other semi-supervised counting models with labeled percentages ranging from 5%to 50%.When the labeled percentage is 5%,the mean absolute error and root mean square error are 17.71 and 25.49,respectively.These findings demonstrate that our work can be used as an efficient semi-supervised counting method to provide automated support for tree breeding and genetic utilization.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.61304155)Beijing Municipal Party Committee Organization Department Talents Project(Grant No.2012D005003000005)Graduate Department of BTBU Comprehensive Reform Project to Promote Talent Cultivation(Grant No.19005428069)
文摘A new family of univariate exponential slash distribution is introduced, which is based on elliptical distributions and defined by means of a stochastic representation as the scale mixture of an elliptically distributed random variable with respect to the power of an exponential random variable. The same idea is extended to the multivariate case. General properties of the resulting families, including their moments and kurtosis coefficient, are stud- ied. And inferences based on methods of moment and maximum likelihood are discussed. A real data is presented to show this family is flexible and fits much better than other related families.
基金Project supported by the National Natural Science Foundation of China (No. 30170770).
文摘Soil organic carbon （C） and total nitrogen （N） pools of a Chinese fir （Cunninghamia lanceolata （Lamb.） Hook.） （CF） forest, and an evergreen broadleaf （EB） forest located in mid-subtropical, southeastern China, were compared before clearcutting, with the effect of slash burning on organic C and total N in the top 10 cm of soil before and after burning also being evaluated. Prior to clearcutting CF forest had significantly lower （P 〈0.05） organic C and total N in the soil （0-100 cm） compared to EB forest with approximately 60% of the C and N at the two forest sites stored at the 0 to 40 cm soil. In post-burn samples of the 0-10 cm depth at 5 days, 1 year, and 5 years for CF and EB forests, significantly lower levels （P 〈0.05） of organic C and total N than those in the pre-burn samples were observed. Compared to the pre-burn levels, at post-burn year 5, surface soil organic C storage was only 85% in CF forest and 72% in EB forest, while total N storage was 77% for CF forest and 73% for EB forest. Slash burning caused marked long-term changes in surface soil C and N in the two forest types.
基金supported by the United States Forest Service and the Forest Biology Research Cooperative at the University of Florida
文摘Carbon sequestration in forests is of great interest due to concerns about global climate change.Carbon storage rates depend on ecosystem fluxes（photosynthesis and ecosystem respiration）,typically quantified as net ecosystem exchange（NEE）.Methods to estimate forest NEE without intensive site sampling are needed to accurately assess rates of carbon sequestration at stand-level and larger scales.We produced spatially-explicit estimates of NEE for 9 770 ha of slash pine（Pinus elliottii） plantations in North-Central Florida for a single year by coupling remote sensing-based estimates of leaf area index（LAI） with a process-based growth simulation model.LAI estimates produced from a neural-network modeling of ground plot and Landsat TM satellite data had a mean of 1.06（range 0-3.93,including forest edges）.Using the neural network LAI values as inputs,the slash pine simulation model（SPM2） estimates of NEE ranged from-5.52 to 11.06 Mg·ha^-1·a^-1with a mean of 3.47 Mg·ha^-1·a^-1Total carbon storage for the year was 33920 t,or about 3.5 tons per hectare.Both estimated LAI and NEE were highly sensitive to fertilization.
文摘During 1991~1995, the growth responses of young slash pine to N, P and K fertilizers and rational rate and ratio of fertilizers in yellow-red soil at Fengshushan Forest Farm, Jiangxi Province were studied. N fertilizer decreased the growth of slash pine, while P not only significantly improved the increment of bottom diameter, height and crown diameter, but also caused earlier canopy closure of the stand. It also had a sustainable effect in the next two years. Slash pine had the most significant response to the treatment of 200 kg P2O5 ha-1, in which tree height, bottom diameter and crown diameter (EW and SN) were increased by 22%, 35%, 20% and 18% in 1994, 21%, 25%, 10% and 10% in 1995, respectively, compared to the control.Although there was no remarkable response to K fertilizer, good growth response to the application of 100 kg P2O5 plus 100 kg K2O ha-1 existed and tree height, bottom diameter and crown diameter (EW and SN)were increased by 31%, 14%, 23% and 21%, respectively, in 1993, compared to the control.
文摘We introduce a new class of the slash distribution using the epsilon half normal distribution. The newly defined model extends the slashed half normal distribution and has more kurtosis than the ordinary half normal distribution. We study the characterization and properties including moments and some measures based on moments of this distribution. A simulation is conducted to investigate asymptotically the bias properties of the estimators for the parameters. We illustrate its use on a real data set by using maximum likelihood estimation.
基金Chinese Academy of Science and National Natural Science Foundation of China!(No. 39770609).
文摘The three methods of slash disposal in this experiment were no treatment, strip piling and burning. The results obtained from this study showed that the soil erosion, water and nutrient loss were higher in the logged areas by burning than in the logged areas by no treatment and strip piling. The soil and water loss was not serious when the slope degree of the logged area was less than 16o. The survival rate of planted seedlings was higher and the growth was better in the logged areas followed by burning than in the logged areas by no treatment and strip piling. Burning should not be used when the slope was more than 23o.
基金The work was supported by the General Program of the National Natural Science Foundation of China(31,470,635)the Fundamental Research Funds of the Chinese Academy of Forestry(No.CAFYBB2017ZX001-3).
文摘Slash pine(Pinus elliottii Engelm.var.elliottii)is a resin-producing species grown worldwide for significant economic benefits for wood production.Resin tapping cre-ates a carbon sink at the expense of carbon allocation for growth and consequently,wood production may be reduced.Non-structural carbohydrates comprising starch and sugars stored in plant organs,may serve as intermediate pools between assimilation and utilisation.However,the effect of resin tapping between tree growth and non-structural carbo-hydrates is not well understood.This study investigated(1)the effects of resin tapping on radial growth,(2)the effects of resin tapping on non-structural carbohydrate pools in different compartments,and(3)the feasibility of resin pro-duction without disruption of tree growth.Twenty one-year-old slash pines were subjected to resin tapping over two suc-cessive years.Non-structural carbohydrate concentrations in needles,branches,stem phloem,and roots of tapped and untapped trees in summer and winter were determined after the second year of resin harvest.The results showed that tapping had no significant effects on annual increments.Starch was the dominant non-structural carbohydrate frac-tion,regardless of tissues and season,and constituted up to 99%of the total non-structural carbohydrates in the phloem and roots.Glucose and fructose were the dominant sugars;sucrose was negligible.Compared with the controls,tapped trees showed 26%lower non-structural carbohydrate concen-tration in the phloem above the tapping wound in summer,which was attributable to the decreased abundance of starch,glucose,fructose,and sucrose.In winter,the altered non-structural carbohydrate profiles in the phloem above the tap-ping wounding were minimised as a result of recovery of the sugar concentrations.In contrast to free sugars,which accu-mulated substantially in needles and branches during winter,starch was enriched in the phloem,roots,and current-year needles.The results provide evidence for a localised effect of resin tapping,and highlight the observation that resin extrac-tion does not always cause a sacrifice in wood growth under a moderate resin-tapping intensity in slash pine plantations.
文摘ZTE Corporation (ZTE), a leading global provider of telecommunications equipment and network solutions, revealed on May 6, 2008 that its award winning Broadband Universal Access System could help operators make a major impact on their carbon footprint as well as save millions of dollars a year in power costs. ZTE’s DSLAM ZXDSL FSAP 9806H overreaches the European code of conduct on energy consumption for broadband equipment, offering a significant power consumption savings per port.
文摘Slash-and-burn practices used by farmers in prior growing periods could affect soil quality, particularly topsoil properties. This study aimed to assess soil biophysical and chemical properties at different landscape levels within the watershed site. Soil samples were collected by a core method in the topsoil layer in slash-and-burn sites. Field analysis was on bulk density and porosity by the gravimetric method, while laboratory analysis was done on organic matter by the Loss on Ignitions Method and other macronutrients for crops (total nitrogen, phosphorus availability, and potassium availability) followed standard analytical methods. To see if there was a significant difference between sites, DMRT 5% was used. The results of the study showed slash-and-burn practice affects soil physical properties such that high bulk density in upstream, midstream, and downstream ranged from 1.55 g/cm<sup>3</sup> to 1.71 g/cm<sup>3</sup>, 1.55 g/cm<sup>3</sup> to 1.80 g/cm<sup>3</sup>, and 1.38 g/cm<sup>3 </sup>to 1.79 g/cm<sup>3</sup> respectively. Poor porosity in upstream, midstream, and downstream ranged from 33.91% to 40.06%, 30.38% to 41.75%, and 30.91% to 46.65%, respectively. Organic matter content was low in the upstream, midstream, and downstream areas, ranging from 2.86% to 3.39%, 2.58% to 3.88%, and 2.91% to 3.88%, respectively. However, soil pH remains neutral, and nitrogen levels are low but near-optimal in the upstream and very low in the midstream and downstream. Phosphorus is extremely high upstream but very low in midstream and downstream. However, potassium remains at a low level close optimum level in the entire watershed.
文摘Biochar production from woody biomass generated during forest management(slash)offers significant benefits for soil health and carbon emissions,yet its adoption remains limited in the western United States(U.S.).To address this challenge,the U.S.Department of Agriculture(U.S.D.A.)Forest Service Rocky Mountain Research Station organized two workshops focused on forest management-centric biochar production.These workshops convened a diverse group of stakeholders,including investors,land management practitioners,industry professionals,and research scientists,each with unique roles in slash-based biochar production.This article presents a synthesis of the insights and perspectives gathered from these workshops,aiming to identify barriers and propose viable pathways for overcoming them.The barriers encompass governance issues such as policy and permitting,economic challenges related to costs,funding,and market stability,technological hurdles concerning methods and equipment,and a need for further research and improved science dissemination.In response to these challenges,workshop attendees collaboratively outlined specific strategies to reduce these barriers.These strategies emphasize the expansion of operational initiatives,the development of proactive policies,the stabilization of biochar markets,and the generation of additional case studies showcasing the effects of biochar amendments across various soils and environments.Collectively,the insights gleaned from this workshop series provide a comprehensive roadmap outlining both the struggles and the necessary actions and investments required to enhance the scale of slash-based biochar production and application in the western U.S.
基金supported by the Shandong Province Natural Science Foundation Youth Branch under grant ZR20-23QF016the Biological Breeding-Major projects(Grant no.2023ZD040580105)the Fundamental Research Funds of CAF(CAFYBB2022QA001).
文摘The new shoot density of slash pine serves as a vital indicator for assessing its growth and photosynthetic capacity,while the number of new shoots offers an intuitive reflection of this density.With deep learning methods becoming increasingly popular,automated counting of new shoots has greatly improved in recent years but is still limited by tedious and expensive data collection and labeling.To resolve these issues,this paper proposes a semi-supervised counting network(MTSC-Net)for estimating the number of slash pine new shoots.First,based on the mean-teacher framework,we introduce the improved VGG19 to extract multiscale new shoot features.Second,to connect local new shoot feature information with global channel features,attention feature fusion module is introduced to achieve effective feature fusion.Finally,the new shoot density map and density probability distribution are processed in a fine-grained manner through multiscale dilated convolution of the regression head and classification head.In addition,a masked image modeling strategy is introduced to encourage the contextual understanding of global new shoot features and improve the counting performance.The experimental results show that MTSC-Net outperforms other semi-supervised counting models with labeled percentages ranging from 5%to 50%.When the labeled percentage is 5%,the mean absolute error and root mean square error are 17.71 and 25.49,respectively.These findings demonstrate that our work can be used as an efficient semi-supervised counting method to provide automated support for tree breeding and genetic utilization.
