The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing tim...The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were simulated and compared by employing field plot experiment and linear regression analysis. [Result] The sowing time had a great impact on plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. With the delay of sowing time, the plant height and DW/FW ratio of forage sorghum decreased, while the leaf stem ratio increased. The regression models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were established： plant height and sowing time, yheight = 234.725- 5.005X; leaf stem ratio and sowing time,ylcaf= 0.096 ＋ 0,019x; DW/FW ratio and sowing time, ydry= 0.305-0.002X. From July 23rd to August 30th, the plant height of forage sorghum was reduced by 5.005 cm, the leaf stem ratio was increased by 0.019 and the DW/FW ratio was reduced by 0.002 in average when hhe sowing time was delayed by one day. [Conclusion] This study provides a theoretical support for the production of forage sorghum in autumn idle land.展开更多
Senesced-leaf nutrient concentrations vary signifcantly among coexisting plant species refecting different leaf nutrient use strategies.However,interspecifc variation in senesced-leaf nutrients and its driving factors...Senesced-leaf nutrient concentrations vary signifcantly among coexisting plant species refecting different leaf nutrient use strategies.However,interspecifc variation in senesced-leaf nutrients and its driving factors are not well understood.Here,we aimed to determine interspecifc variation and its driving factors in senesced-leaf nutrients.We explored interspecifc variation in carbon(C),nitrogen(N)and phosphorus(P)concentrations in newly fallen leaves of 46 coexisting temperate deciduous woody species across the Maoershan Forest Ecosystem Research Station,Northeast China.The relative importance of 10 biotic factors(i.e.mycorrhiza type,N-fxing type,growth form,shade tolerance,laminar texture,coloring degree,coloring type,peak leaf-coloration date,peak leaf-fall date and end leaf-fall date)was quantifed with the random forest model.N and P concentrations varied 4-and 9-fold among species,respectively.The high mean N(15.38 mg·g^(−1))and P(1.24 mg·g^(−1))concentrations suggested a weak N and P limitation in the studied forest.Functional groups had only signifcant effects on specifc nutrients and their ratios.P concentration and N:P were negatively correlated with peak and end leaf-fall dates for the ectomycorrhiza species group.Brighter-colored leaves(red>brown>yellow>yellow-green>green)tended to have lower N and P concentrations and higher C:N and C:P than darker-colored leaves.The random forest model showed that autumn coloration and leaf-fall phenology contributed 80%to the total explanation of nutrient variability among species.The results increase our understanding of the variability in senesced-leaf nutrients as a strategy of woody plant nutrition in temperate forests.展开更多
[目的]运用秋季灌木叶片色彩属性变化规律,从定性、定量的视角构建哈尔滨秋季植物景观的色彩,总结地域性植物色彩设计的科学性。[方法]以能够兼容CAD和Photoshop绘图软件的NCS色卡,在温侯法界定的哈尔滨秋季时段,随秋季时序采集8种灌木...[目的]运用秋季灌木叶片色彩属性变化规律,从定性、定量的视角构建哈尔滨秋季植物景观的色彩,总结地域性植物色彩设计的科学性。[方法]以能够兼容CAD和Photoshop绘图软件的NCS色卡,在温侯法界定的哈尔滨秋季时段,随秋季时序采集8种灌木的NCS色彩值,确定其色彩属性与变化规律。通过采集哈尔滨秋季气温日温的最低、最高值,分析其叶片NCS色彩值与气候温度的日温差、最低最高温度变化的规律。[结果]8种灌木NCS叶色值总体范围为NCS S 5540-G40Y^NCS S 1580-Y90R,分布于24个标准颜色中。最低气温9℃,日温差11℃,叶片开始变色3种;最低气温9℃,日温差15℃,叶片开始变色3种;最低气温7℃,日温差10℃,叶片开始变色1种;霜后,最低气温5℃,日温差13℃,叶片开始变色1种。最低气温7℃持续2d,连续日温差8~13℃,进入变色盛期7种;最低气温3℃,日温差13℃,进入变色盛期1种。[结论]利用秋季灌木叶片色彩属性变化规律构建哈尔滨秋季植物景观色彩是提升秋季季相色彩设计质量的重要途径,具有一定的科学性。展开更多
文摘The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were simulated and compared by employing field plot experiment and linear regression analysis. [Result] The sowing time had a great impact on plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. With the delay of sowing time, the plant height and DW/FW ratio of forage sorghum decreased, while the leaf stem ratio increased. The regression models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were established： plant height and sowing time, yheight = 234.725- 5.005X; leaf stem ratio and sowing time,ylcaf= 0.096 ＋ 0,019x; DW/FW ratio and sowing time, ydry= 0.305-0.002X. From July 23rd to August 30th, the plant height of forage sorghum was reduced by 5.005 cm, the leaf stem ratio was increased by 0.019 and the DW/FW ratio was reduced by 0.002 in average when hhe sowing time was delayed by one day. [Conclusion] This study provides a theoretical support for the production of forage sorghum in autumn idle land.
基金funded by the National Natural Science Foundation of China(32171765)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R09)。
文摘Senesced-leaf nutrient concentrations vary signifcantly among coexisting plant species refecting different leaf nutrient use strategies.However,interspecifc variation in senesced-leaf nutrients and its driving factors are not well understood.Here,we aimed to determine interspecifc variation and its driving factors in senesced-leaf nutrients.We explored interspecifc variation in carbon(C),nitrogen(N)and phosphorus(P)concentrations in newly fallen leaves of 46 coexisting temperate deciduous woody species across the Maoershan Forest Ecosystem Research Station,Northeast China.The relative importance of 10 biotic factors(i.e.mycorrhiza type,N-fxing type,growth form,shade tolerance,laminar texture,coloring degree,coloring type,peak leaf-coloration date,peak leaf-fall date and end leaf-fall date)was quantifed with the random forest model.N and P concentrations varied 4-and 9-fold among species,respectively.The high mean N(15.38 mg·g^(−1))and P(1.24 mg·g^(−1))concentrations suggested a weak N and P limitation in the studied forest.Functional groups had only signifcant effects on specifc nutrients and their ratios.P concentration and N:P were negatively correlated with peak and end leaf-fall dates for the ectomycorrhiza species group.Brighter-colored leaves(red>brown>yellow>yellow-green>green)tended to have lower N and P concentrations and higher C:N and C:P than darker-colored leaves.The random forest model showed that autumn coloration and leaf-fall phenology contributed 80%to the total explanation of nutrient variability among species.The results increase our understanding of the variability in senesced-leaf nutrients as a strategy of woody plant nutrition in temperate forests.
文摘[目的]运用秋季灌木叶片色彩属性变化规律,从定性、定量的视角构建哈尔滨秋季植物景观的色彩,总结地域性植物色彩设计的科学性。[方法]以能够兼容CAD和Photoshop绘图软件的NCS色卡,在温侯法界定的哈尔滨秋季时段,随秋季时序采集8种灌木的NCS色彩值,确定其色彩属性与变化规律。通过采集哈尔滨秋季气温日温的最低、最高值,分析其叶片NCS色彩值与气候温度的日温差、最低最高温度变化的规律。[结果]8种灌木NCS叶色值总体范围为NCS S 5540-G40Y^NCS S 1580-Y90R,分布于24个标准颜色中。最低气温9℃,日温差11℃,叶片开始变色3种;最低气温9℃,日温差15℃,叶片开始变色3种;最低气温7℃,日温差10℃,叶片开始变色1种;霜后,最低气温5℃,日温差13℃,叶片开始变色1种。最低气温7℃持续2d,连续日温差8~13℃,进入变色盛期7种;最低气温3℃,日温差13℃,进入变色盛期1种。[结论]利用秋季灌木叶片色彩属性变化规律构建哈尔滨秋季植物景观色彩是提升秋季季相色彩设计质量的重要途径,具有一定的科学性。
