【目的】划分森林群落类型,定量分析森林群落形成与其环境因子和火干扰因子之间的关系,为新疆喀纳斯泰加林群落物种多样性保护与森林可持续经营提供科学依据。【方法】以新疆喀纳斯泰加林火成演替森林群落为研究对象,基于149个森林群落...【目的】划分森林群落类型,定量分析森林群落形成与其环境因子和火干扰因子之间的关系,为新疆喀纳斯泰加林群落物种多样性保护与森林可持续经营提供科学依据。【方法】以新疆喀纳斯泰加林火成演替森林群落为研究对象,基于149个森林群落样地及其火干扰发生时间和火烈度的调查,采用双向指示种分析(two-way indicator species analysis,TWINSPAN)方法对喀纳斯国家自然保护区科学实验区处于不同演替阶段的森林群落进行群落类型划分,并采用冗余分析(redundancy analysis,RDA)方法通过对其森林群落进行排序,分析森林群落形成与环境因子和火干扰因子的关系,定量分离环境因子、火干扰因子及其二者的交互作用对森林群落形成的影响。【结果】 1)TWINSPAN将149个森林群落调查样地划分为16种森林群落类型;2)RDA排序结果较好地反映了喀纳斯泰加林群落形成与环境因子和火干扰因子之间的关系,环境因子中的海拔、坡位、坡度、坡向、土壤有机质和全钾含量对森林群落的形成起较大的作用,其中海拔、坡位、坡度和坡向与RDA第1排序轴存在极显著相关性( P <0.01),土壤有机质和全钾含量与RDA第1排序轴存在显著相关性( P <0.05);火干扰因子中的火烈度对森林群落形成也起较大的作用,火烈度与RDA第2排序轴存在极显著相关性( P <0.01);3)因子分离显示,在影响喀纳斯泰加林群落形成的因素中,环境因子解释的部分占21.96%,火干扰因子解释的部分占1.80%,二者交互作用解释的部分占49.82%,未能解释的部分占26.42%。【结论】喀纳斯国家自然保护区科学实验区有16种森林群落类型,其森林群落形成受环境因子和火干扰因子的共同控制,并且二者的交互作用尤为突出。火干扰是新疆喀纳斯泰加林群落物种多样性保护与森林可持续经营不可或缺的重要因素。展开更多
Forest recovery may be influenced by several factors, of which fire is the most critical.However, moderate-and long-term effects of fire on forest recovery are less researched in Northwest China.Thus, the effects of d...Forest recovery may be influenced by several factors, of which fire is the most critical.However, moderate-and long-term effects of fire on forest recovery are less researched in Northwest China.Thus, the effects of different forest recovery time after fire(1917(served as the control), 1974, 1983 and 1995) and fire severities(low, moderate and high) on larch(Larix sibirica Ledeb.) forest were investigated in the Kanas National Nature Reserve(KNNR), Northwest China in 2017.This paper analyzed post-fire changes in stand density, total basal area(TBA), litter mass, soil organic carbon(SOC) and soil nutrients(total nitrogen, total phosphorus and total potassium) with one-way analyses of variance.Results indicate that litter mass, TBA, SOC and soil nutrients increased with increasing recovery time after fire and decreasing fire severity, while the stand density showed an opposite response.The effects of fire disturbance on SOC and soil nutrients decreased with increasing soil depth.Moreover, we found that the time of more than 43 a is needed to recover the litter mass, TBA, SOC and soil nutrients to the pre-fire level.In conclusion, high-severity fire caused the greatest variations in stand structure and soil of larch forest, and low-severity fire was more advantageous for post-fire forest stand structure and soil recovery in the KNNR.Therefore, low-severity fire can be an efficient management mean through reducing the accumulation of forest floor fuel of post-fire forests in the KNNR, Northwest China.展开更多
Ping′ou hybrid hazelnut is produced by cross cultivation and is widely cultivated in northern China with good development prospects.Based on a field experiment of fertilizer efficiency,the leaf spectral reflectance a...Ping′ou hybrid hazelnut is produced by cross cultivation and is widely cultivated in northern China with good development prospects.Based on a field experiment of fertilizer efficiency,the leaf spectral reflectance and leaf potassium(K)concentration were measured with different quantities of K fertilizer applied at four fruit growth stages(fruit setting stage,fruit rapid growth stage,fruit fat-change stage,and fruit near-maturity stage)of Ping′ou hybrid hazelnut in 2019.Spectral parameters that were significantly correlated with leaf K concentration were selected using Pearson correlation analysis,and spectral parameter estimation models of leaf K concentration were established by employing six different modelling methods(exponential function,power function,logarithmic function,linear function,quadratic function,and cubic function).The results indicated that at the fruit setting period,leaf K concentration was significantly correlated with Dy(spectra slope of yellow edge),Rg(reflectance of the green peak position),λo(red valley position),SDb(blue edge area),SDr/SDb(where SDr represents red edge area),and(SDr–SDb)/(SDr+SDb)(P<0.01).There were significant correlations of leaf K concentration with Dy,Rg,SDb,Rg/Ro(where Ro is the reflectance of the red valley position),and(Rg–Ro)/(Rg+Ro)at the fruit rapid growth stage(P<0.01).Further,significant correlations of leaf K concentration with Rg,Ro,RNIR/Green,and RNIR/Blue were obtained at the fruit fat-change period(P<0.01).Finally,leaf K concentration showed significant correlations with Dr,Rg,Ro,SDy(yellow edge area),and SDr at the fruit near-maturity stage(P<0.01).Through a cubic function analysis,regression estimation model of leaf K concentration with highest fitting degree(R2)values at the four fruit growth stages was established.The findings in this study demonstrated that it is feasible to estimate leaf K concentration of Ping′ou hybrid hazelnut at the various phenological stages of fruit development by establishing regression models between leaf K concentration and spectral parameters.展开更多
文摘【目的】划分森林群落类型,定量分析森林群落形成与其环境因子和火干扰因子之间的关系,为新疆喀纳斯泰加林群落物种多样性保护与森林可持续经营提供科学依据。【方法】以新疆喀纳斯泰加林火成演替森林群落为研究对象,基于149个森林群落样地及其火干扰发生时间和火烈度的调查,采用双向指示种分析(two-way indicator species analysis,TWINSPAN)方法对喀纳斯国家自然保护区科学实验区处于不同演替阶段的森林群落进行群落类型划分,并采用冗余分析(redundancy analysis,RDA)方法通过对其森林群落进行排序,分析森林群落形成与环境因子和火干扰因子的关系,定量分离环境因子、火干扰因子及其二者的交互作用对森林群落形成的影响。【结果】 1)TWINSPAN将149个森林群落调查样地划分为16种森林群落类型;2)RDA排序结果较好地反映了喀纳斯泰加林群落形成与环境因子和火干扰因子之间的关系,环境因子中的海拔、坡位、坡度、坡向、土壤有机质和全钾含量对森林群落的形成起较大的作用,其中海拔、坡位、坡度和坡向与RDA第1排序轴存在极显著相关性( P <0.01),土壤有机质和全钾含量与RDA第1排序轴存在显著相关性( P <0.05);火干扰因子中的火烈度对森林群落形成也起较大的作用,火烈度与RDA第2排序轴存在极显著相关性( P <0.01);3)因子分离显示,在影响喀纳斯泰加林群落形成的因素中,环境因子解释的部分占21.96%,火干扰因子解释的部分占1.80%,二者交互作用解释的部分占49.82%,未能解释的部分占26.42%。【结论】喀纳斯国家自然保护区科学实验区有16种森林群落类型,其森林群落形成受环境因子和火干扰因子的共同控制,并且二者的交互作用尤为突出。火干扰是新疆喀纳斯泰加林群落物种多样性保护与森林可持续经营不可或缺的重要因素。
基金supported by the National Natural Science Foundation of China (31570634)the Project of Xinjiang Agricultural Vocational College (XJNZYKJ201712)
文摘Forest recovery may be influenced by several factors, of which fire is the most critical.However, moderate-and long-term effects of fire on forest recovery are less researched in Northwest China.Thus, the effects of different forest recovery time after fire(1917(served as the control), 1974, 1983 and 1995) and fire severities(low, moderate and high) on larch(Larix sibirica Ledeb.) forest were investigated in the Kanas National Nature Reserve(KNNR), Northwest China in 2017.This paper analyzed post-fire changes in stand density, total basal area(TBA), litter mass, soil organic carbon(SOC) and soil nutrients(total nitrogen, total phosphorus and total potassium) with one-way analyses of variance.Results indicate that litter mass, TBA, SOC and soil nutrients increased with increasing recovery time after fire and decreasing fire severity, while the stand density showed an opposite response.The effects of fire disturbance on SOC and soil nutrients decreased with increasing soil depth.Moreover, we found that the time of more than 43 a is needed to recover the litter mass, TBA, SOC and soil nutrients to the pre-fire level.In conclusion, high-severity fire caused the greatest variations in stand structure and soil of larch forest, and low-severity fire was more advantageous for post-fire forest stand structure and soil recovery in the KNNR.Therefore, low-severity fire can be an efficient management mean through reducing the accumulation of forest floor fuel of post-fire forests in the KNNR, Northwest China.
基金the National Natural Science Foundation of China(31960324)。
文摘Ping′ou hybrid hazelnut is produced by cross cultivation and is widely cultivated in northern China with good development prospects.Based on a field experiment of fertilizer efficiency,the leaf spectral reflectance and leaf potassium(K)concentration were measured with different quantities of K fertilizer applied at four fruit growth stages(fruit setting stage,fruit rapid growth stage,fruit fat-change stage,and fruit near-maturity stage)of Ping′ou hybrid hazelnut in 2019.Spectral parameters that were significantly correlated with leaf K concentration were selected using Pearson correlation analysis,and spectral parameter estimation models of leaf K concentration were established by employing six different modelling methods(exponential function,power function,logarithmic function,linear function,quadratic function,and cubic function).The results indicated that at the fruit setting period,leaf K concentration was significantly correlated with Dy(spectra slope of yellow edge),Rg(reflectance of the green peak position),λo(red valley position),SDb(blue edge area),SDr/SDb(where SDr represents red edge area),and(SDr–SDb)/(SDr+SDb)(P<0.01).There were significant correlations of leaf K concentration with Dy,Rg,SDb,Rg/Ro(where Ro is the reflectance of the red valley position),and(Rg–Ro)/(Rg+Ro)at the fruit rapid growth stage(P<0.01).Further,significant correlations of leaf K concentration with Rg,Ro,RNIR/Green,and RNIR/Blue were obtained at the fruit fat-change period(P<0.01).Finally,leaf K concentration showed significant correlations with Dr,Rg,Ro,SDy(yellow edge area),and SDr at the fruit near-maturity stage(P<0.01).Through a cubic function analysis,regression estimation model of leaf K concentration with highest fitting degree(R2)values at the four fruit growth stages was established.The findings in this study demonstrated that it is feasible to estimate leaf K concentration of Ping′ou hybrid hazelnut at the various phenological stages of fruit development by establishing regression models between leaf K concentration and spectral parameters.
