Elevation changes may affect intraspecific relationships or interspecific relationships among species.However,previous studies on Quercus variabilis have rarely investigated how its population interactions vary with e...Elevation changes may affect intraspecific relationships or interspecific relationships among species.However,previous studies on Quercus variabilis have rarely investigated how its population interactions vary with elevation and how the factors affect them.Here,we examined the species relationships in Q.variabilis natural secondary forests across the three different elevation ranges(lower,medium,and higher elevation areas)using the niche and the Hegyi competition method.As the elevation increased,Q.variabilis strengthened its dominant position,and the overall association between populations shifted from positive to negative,as evidenced by a significant decrease in the positive-to-negative correlation ratio from 0.45(85/191)to 0.41(80/196)and then to 0.32(29/91),indicating that the interspecific relationship gradually transitioned from facilitation to competition.The ratios of the intraspecific competition index to interspecific competition index were 3.09,8.92 and 6.82,respectively,indicating that Q.variabilis forests had greater intraspecific competition compared to interspecific competition,especially in the medium elevation area.The intraspecific and interspecific competition in the lower and medium elevation areas showed a decreasing trend with the increase of diameter class,while the competition among individuals in the higher elevation area became more stable.The SEM showed that soil properties were indirectly negatively correlated with the species competition through a significant negative effect on forest density,while community characteristics only had a significant negative effect on intraspecific competition.Our results demonstrated that elevation factors decreased the intraspecific and interspecific relationships within Q.variabilis forests,providing new insights into the effective conservation of Q.variabilis natural forests.展开更多
By measuring the contents of soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(P)in rhizosphere and non-rhizosphere soils of Quercus variabilis forests with different ages(22,35,and 45 a)and origins(nat...By measuring the contents of soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(P)in rhizosphere and non-rhizosphere soils of Quercus variabilis forests with different ages(22,35,and 45 a)and origins(natural forests and planted forests)in the Funiu Mountain area,the stoichiometric characteristics of carbon,nitrogen,and phosphorus in Q.variabilis forest soils were evaluated.The research results indicated that:(i)there were significant differences(P<0.05)in the SOC content between the rhizosphere and non-rhizosphere soils of Q.variabilis planted forests at different stand ages.Moreover,as the stand age increased,the SOC content in both the rhizosphere and non-rhizosphere soils of the planted forests initially decreased and then increased.The TN and TP contents in the rhizosphere and non-rhizosphere soils of Q.variabilis planted forests did not show significant differences across different stand ages,and they exhibited different trends as the stand age increased.(ii)The SOC and nitrogen to phosphorus ratio(N:P)exhibited significant rhizosphere effects,whereas the rhizosphere effects of the TN,TP,carbon to nitrogen ratio(C:N),and carbon to phosphorus ratio(C:P)were not prominent.In terms of the influence of stand age,the SOC,TN,TP,C:P,and N:P were significantly affected.However,the effect of the C:N at the stand age level was not significant.The interactive effects of soil carbon,nitrogen,phosphorus,and their stoichiometric ratios were all significant.It is recommended to appropriately supplement soil nitrogen and phosphorus to ensure the sustainable development of Q.variabilis forest stand.展开更多
基金supported by the Science and Technology for Forestry Project of Henan Province(YLK202405)the Key Science and Technology Research Project of Henan Province(222102110418).
文摘Elevation changes may affect intraspecific relationships or interspecific relationships among species.However,previous studies on Quercus variabilis have rarely investigated how its population interactions vary with elevation and how the factors affect them.Here,we examined the species relationships in Q.variabilis natural secondary forests across the three different elevation ranges(lower,medium,and higher elevation areas)using the niche and the Hegyi competition method.As the elevation increased,Q.variabilis strengthened its dominant position,and the overall association between populations shifted from positive to negative,as evidenced by a significant decrease in the positive-to-negative correlation ratio from 0.45(85/191)to 0.41(80/196)and then to 0.32(29/91),indicating that the interspecific relationship gradually transitioned from facilitation to competition.The ratios of the intraspecific competition index to interspecific competition index were 3.09,8.92 and 6.82,respectively,indicating that Q.variabilis forests had greater intraspecific competition compared to interspecific competition,especially in the medium elevation area.The intraspecific and interspecific competition in the lower and medium elevation areas showed a decreasing trend with the increase of diameter class,while the competition among individuals in the higher elevation area became more stable.The SEM showed that soil properties were indirectly negatively correlated with the species competition through a significant negative effect on forest density,while community characteristics only had a significant negative effect on intraspecific competition.Our results demonstrated that elevation factors decreased the intraspecific and interspecific relationships within Q.variabilis forests,providing new insights into the effective conservation of Q.variabilis natural forests.
基金Sponsored by the National Natural Science Foundation of China(32271848).
文摘By measuring the contents of soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(P)in rhizosphere and non-rhizosphere soils of Quercus variabilis forests with different ages(22,35,and 45 a)and origins(natural forests and planted forests)in the Funiu Mountain area,the stoichiometric characteristics of carbon,nitrogen,and phosphorus in Q.variabilis forest soils were evaluated.The research results indicated that:(i)there were significant differences(P<0.05)in the SOC content between the rhizosphere and non-rhizosphere soils of Q.variabilis planted forests at different stand ages.Moreover,as the stand age increased,the SOC content in both the rhizosphere and non-rhizosphere soils of the planted forests initially decreased and then increased.The TN and TP contents in the rhizosphere and non-rhizosphere soils of Q.variabilis planted forests did not show significant differences across different stand ages,and they exhibited different trends as the stand age increased.(ii)The SOC and nitrogen to phosphorus ratio(N:P)exhibited significant rhizosphere effects,whereas the rhizosphere effects of the TN,TP,carbon to nitrogen ratio(C:N),and carbon to phosphorus ratio(C:P)were not prominent.In terms of the influence of stand age,the SOC,TN,TP,C:P,and N:P were significantly affected.However,the effect of the C:N at the stand age level was not significant.The interactive effects of soil carbon,nitrogen,phosphorus,and their stoichiometric ratios were all significant.It is recommended to appropriately supplement soil nitrogen and phosphorus to ensure the sustainable development of Q.variabilis forest stand.
