Phosphorus(P)is an important nutrient element in the photosynthesis process of plants.The effect of stand age on P nutrient dynamics in subtropical plantations is unclear.In this study,the mechanisms of above-and belo...Phosphorus(P)is an important nutrient element in the photosynthesis process of plants.The effect of stand age on P nutrient dynamics in subtropical plantations is unclear.In this study,the mechanisms of above-and belowground P cycling in subtropical P.massoniana plantations of different stand ages(5,9,19,29 and 35 years)were investigated.The percentage of metabolic P in leaves exhibited an initial rise and subsequent decline with stand age of P.massoniana throughout the growing season,culminating in a metabolic P proportion of 34%–68% in litter.During the non-growing season,the main change in the P components of P.massoniana fine roots was a transition from metabolic P to residual P.Relative to during the growing season,soil ligand P fractions decreased by 7%–22% and exchangeable P fractions increased by 0–16%in the non-growing season.Organ P components tended to decrease with increasing stand age,mainly due to the gradual decrease in soil-bioavailable P,a trend alleviated by litter input.The generation of dissolved P by soil phosphatases would limit the reduction in soilbioavailable P caused by leaf P resorption to some extent.The differences in leaf organ P components between the growing and non-growing seasons are attributed to the allocation of P by the P.massoniana.Overall,the results of this study provide a basis for exploring the mechanisms of soil bioavailable P and soil P enzymemediated organ P component allocation in P.massoniana forests.These findings will help improve the management of P-limited P.massoniana plantations to enhance their productivity.展开更多
The insufficient supply of phosphorus is the main problem facing agriculture and forestry production in red soil region of southern China.To investigate whether applying bag-controlled slow-release fertilizer can impr...The insufficient supply of phosphorus is the main problem facing agriculture and forestry production in red soil region of southern China.To investigate whether applying bag-controlled slow-release fertilizer can improve the phosphorus availability and available phosphorus component content,with Gaofeng State-owned Eucalyptus Plantations Forest Farm in Guangxi red soil region as the research object,comparative test of different fertilizer types and fertilizer amount of bag-controlled slow-release fertilizer with conventional fertilization(G1),bag-controlled slow-release fertilizer with reducing fertilization(G2),traditional compound fertilizer(G3),basal fertilizer(G4),and no fertilization(G5)was designed.Soil phosphorus classification method was used to determine the content of phosphorus components in the soil,and redundancy analysis was used to study the effects of components on tree growth.The results showed that:compared with traditional fertilization,bag-controlled slow-release fertilizer significantly increased the contents of AP,Pi,Fe-P and other components in soil;the phosphorus activation coefficients of G2 and G1 were significantly higher than those of the other three treatments,and the order was G2>G1>G4>G5>G3;redundancy analysis showed that PAC and Fe-P had the most significant effect on plant growth among all phosphorus components.The application of bag-controlled slow-release fertilizer in red soil of eucalyptus plantation in southern China could promote the accumulation of phosphorus and increase the phosphorus activity.The mechanism of higher phosphorus use efficiency in bag-controlled slow-release fertilizer was mainly through the sustained phosphorus input and reducing phosphorus immobilization in soil by obstructing the contact of phosphorus with acid soil,to guarantee the phosphorus supply in tree growth process.展开更多
Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and...Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and phosphorus stoichiometry is beneficial to the nitrogen and phosphorus pollution management in pond ecosystems. In this study, 18 groups (36 in total) of typical cascade ponds were selected as long-term observations to investigate the spatial distribution patterns of nitrogen and phosphorus component ratios (ratio of total nitrogen to phosphorus: TN:TP, ratio of dissolved nitrogen to phosphorus: TDN:TDP, ratio of particulate nitrogen to phosphorus: PN:PP) in water bodies in the tropical agricultural watershed of Jinjing. The results showed that the average values of TN:TP and TDN:TDP in the upstream ponds were 26.4 and 53.4, respectively, and were more than those in the downstream (22.95 and 48.1, respectively). In contrast, the PN:PP (13.78) in the upstream was significantly lower than that of the downstream (30.39). Furthermore, the factors of rainfall, agricultural land use and fish farming influenced the spatio-temporal variability of the N:P ratios. The ratios of TN:TP and TDN:TDP were higher in the wet season and lower in the dry season. Agricultural land use and fish farming reduced the ratios of the above three nitrogen and phosphorus components in cascade ponds in the study area. Our results show that strengthening agricultural land pollution control and aquaculture management could help to improve water quality of pond ecosystems in the study area.展开更多
基金supported by the Fundamental Research Funds for the Central Non-profit Research Institution(CAFYBB2021QD002-2 and CAFYBB2020ZE001)the National Key Research and Development Program of China(2023YFD2200404-02)the Qianjiangyuan National Forest Ecological Research Station.
文摘Phosphorus(P)is an important nutrient element in the photosynthesis process of plants.The effect of stand age on P nutrient dynamics in subtropical plantations is unclear.In this study,the mechanisms of above-and belowground P cycling in subtropical P.massoniana plantations of different stand ages(5,9,19,29 and 35 years)were investigated.The percentage of metabolic P in leaves exhibited an initial rise and subsequent decline with stand age of P.massoniana throughout the growing season,culminating in a metabolic P proportion of 34%–68% in litter.During the non-growing season,the main change in the P components of P.massoniana fine roots was a transition from metabolic P to residual P.Relative to during the growing season,soil ligand P fractions decreased by 7%–22% and exchangeable P fractions increased by 0–16%in the non-growing season.Organ P components tended to decrease with increasing stand age,mainly due to the gradual decrease in soil-bioavailable P,a trend alleviated by litter input.The generation of dissolved P by soil phosphatases would limit the reduction in soilbioavailable P caused by leaf P resorption to some extent.The differences in leaf organ P components between the growing and non-growing seasons are attributed to the allocation of P by the P.massoniana.Overall,the results of this study provide a basis for exploring the mechanisms of soil bioavailable P and soil P enzymemediated organ P component allocation in P.massoniana forests.These findings will help improve the management of P-limited P.massoniana plantations to enhance their productivity.
基金Supported by Special Item of Basic Business Expenses of Guangxi Academy of Forestry Sciences(LINKE 202113)Forestry Science and Technology Promotion Demonstration Project of the Central Finance([2021]TG18)Special Fund Project for Innovation Driven Development in Guangxi(GUIKE AA17204087-11)。
文摘The insufficient supply of phosphorus is the main problem facing agriculture and forestry production in red soil region of southern China.To investigate whether applying bag-controlled slow-release fertilizer can improve the phosphorus availability and available phosphorus component content,with Gaofeng State-owned Eucalyptus Plantations Forest Farm in Guangxi red soil region as the research object,comparative test of different fertilizer types and fertilizer amount of bag-controlled slow-release fertilizer with conventional fertilization(G1),bag-controlled slow-release fertilizer with reducing fertilization(G2),traditional compound fertilizer(G3),basal fertilizer(G4),and no fertilization(G5)was designed.Soil phosphorus classification method was used to determine the content of phosphorus components in the soil,and redundancy analysis was used to study the effects of components on tree growth.The results showed that:compared with traditional fertilization,bag-controlled slow-release fertilizer significantly increased the contents of AP,Pi,Fe-P and other components in soil;the phosphorus activation coefficients of G2 and G1 were significantly higher than those of the other three treatments,and the order was G2>G1>G4>G5>G3;redundancy analysis showed that PAC and Fe-P had the most significant effect on plant growth among all phosphorus components.The application of bag-controlled slow-release fertilizer in red soil of eucalyptus plantation in southern China could promote the accumulation of phosphorus and increase the phosphorus activity.The mechanism of higher phosphorus use efficiency in bag-controlled slow-release fertilizer was mainly through the sustained phosphorus input and reducing phosphorus immobilization in soil by obstructing the contact of phosphorus with acid soil,to guarantee the phosphorus supply in tree growth process.
文摘Ecological stoichiometry of nitrogen and phosphorus is an important indicator to characterize the nitrogen and phosphorus trophic status in aquatic ecosystems. The study of the spatio-temporal patterns of nitrogen and phosphorus stoichiometry is beneficial to the nitrogen and phosphorus pollution management in pond ecosystems. In this study, 18 groups (36 in total) of typical cascade ponds were selected as long-term observations to investigate the spatial distribution patterns of nitrogen and phosphorus component ratios (ratio of total nitrogen to phosphorus: TN:TP, ratio of dissolved nitrogen to phosphorus: TDN:TDP, ratio of particulate nitrogen to phosphorus: PN:PP) in water bodies in the tropical agricultural watershed of Jinjing. The results showed that the average values of TN:TP and TDN:TDP in the upstream ponds were 26.4 and 53.4, respectively, and were more than those in the downstream (22.95 and 48.1, respectively). In contrast, the PN:PP (13.78) in the upstream was significantly lower than that of the downstream (30.39). Furthermore, the factors of rainfall, agricultural land use and fish farming influenced the spatio-temporal variability of the N:P ratios. The ratios of TN:TP and TDN:TDP were higher in the wet season and lower in the dry season. Agricultural land use and fish farming reduced the ratios of the above three nitrogen and phosphorus components in cascade ponds in the study area. Our results show that strengthening agricultural land pollution control and aquaculture management could help to improve water quality of pond ecosystems in the study area.
