Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P...Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P fractions is potentially an adaptive strategy for plants to cope with soil N(P)availability and nutrient-limiting conditions.However,the impact of the interactions between imbalanced anthropogenic N and P inputs on the concentrations and allocation proportions of leaf P fractions in forest woody plants remains elusive.We conducted a metaanalysis of data about the concentrations and allocation proportions of leaf P fractions,specifically associated with individual and combined additions of N and P in evergreen forests,the dominant vegetation type in southern China where the primary productivity is usually considered limited by P.This assessment allowed us to quantitatively evaluate the effects of N and P additions alone and interactively on leaf P allocation and use strategies.Nitrogen addition(exacerbating P limitation)reduced the concentrations of leaf total P and different leaf P fractions.Nitrogen addition reduced the allocation to leaf metabolic P but increased the allocation to other fractions,while P addition showed opposite trends.The simultaneous additions of N and P showed an antagonistic(mutual suppression)effect on the concentrations of leaf P fractions,but an additive(summary)effect on the allocation proportions of leaf P fractions.These results highlight the importance of strategies of leaf P fraction allocation in forest plants under changes in environmental nutrient availability.Importantly,our study identified critical interactions associated with combined N and P inputs that affect leaf P fractions,thus aiding in predicting plant acclimation strategies in the context of intensifying and imbalanced anthropogenic nutrient inputs.展开更多
Planktonic metabolism plays an important role in affecting the energy transportation and carbon cycle of the marine ecosystem.However,its regulation mechanism remains unclear under the continuously exogenous nutrient ...Planktonic metabolism plays an important role in affecting the energy transportation and carbon cycle of the marine ecosystem.However,its regulation mechanism remains unclear under the continuously exogenous nutrient inputs in nearshore waters.In this study,a mesocosm experiment was conducted in a semi-enclosed bay,the Daya Bay,to explore the responses of plankton metabolic balance and community structure to a concentration gradient of daily nitrogen and phosphorus inputs.The results showed that nutrient enrichments promoted phytoplankton biomass,total primary production,and community respiration,and the promoting effect enhanced alongwith the increase of nutrient concentration.However,the net community production fluctuated more violently between autotrophic and heterotrophic with the increase of nutrient inputs and tended to be more heterotrophic from the 5 th day to the 10 th day of the experiment.In addition,the daily flux of nitrogen and phosphorus,2μmol/(L·d)and 0.066μmol/(L·d),respectively,could be regarded as a potential threshold for ecosystem stability and health,since most of the ecological characteristics related to plankton structure and function have undergone significant changes when the nutrient level is higher than that.In the nearshore enclosed or semi-enclosed waters,nutrient from continuous terrigenous input is likely to be concentrated and exceed this level,indicating the ecological risks due to the metabolic unbalance and the deterioration of plankton community structure.展开更多
为定量化设施果类蔬菜养分投入,实现设施果蔬优质高产、绿色高效生产,本研究以山东省典型设施果类蔬菜为研究对象,基于通过农户调研与土壤样品采集测定收集的数据,结合对现有文献的综述,使用生命周期评价方法,系统分析研究区域设施果类...为定量化设施果类蔬菜养分投入,实现设施果蔬优质高产、绿色高效生产,本研究以山东省典型设施果类蔬菜为研究对象,基于通过农户调研与土壤样品采集测定收集的数据,结合对现有文献的综述,使用生命周期评价方法,系统分析研究区域设施果类蔬菜生产的施肥现状、土壤养分状况和环境代价及其相关关系。结果表明:山东省主栽设施果类蔬菜养分投入量高,设施番茄、黄瓜、辣椒、茄子的氮(以N计)、磷(以P2O5计)、钾(以K2O计)投入量平均达到743、600、740 kg·hm^(-2),施肥变异系数较大(CV=30.3%~43.9%),大量的肥料投入造成了较高的养分盈余,进而导致表层土壤(0~30 cm)养分含量显著升高,同时导致了较高的环境代价。设施果类蔬菜的单位面积上活性氮损失、温室气体排放、富营养化效应和酸化效应均以黄瓜生产系统最高,分别达225 kg·hm^(-2)、10058 kg CO_(2e)·hm^(-2)、124 kg PO_(4e)·hm^(-2)和63.4 kg SO_(2e)·hm^(-2),其次是茄子、番茄和辣椒。氮素盈余是导致活性氮损失的最主要因素,氮、磷、钾肥料的生产过程和施用过程是设施果类蔬菜温室气体排放、富营养化效应和酸化效应的主要贡献因子,贡献率高达80%以上。因此,为保证设施果类蔬菜产业绿色优质高质量发展,应通过优化设施蔬菜养分资源综合管理策略来减少养分盈余、降低环境代价。展开更多
In order to measure dust's nutrient input on farmland in different agro-ecological zones, Harmattan dust was sampled by mats with plastic straw in Ghana between 2002–2006. The inputs of total nutrients by Harmatt...In order to measure dust's nutrient input on farmland in different agro-ecological zones, Harmattan dust was sampled by mats with plastic straw in Ghana between 2002–2006. The inputs of total nutrients by Harmattan dust in Ghana per Harmattan period were about 1–2 kg Ca ha-1, 0.5–2 kg K ha-1, 0.5–1.5 kg Mg ha-1and less than 0.5 kg P ha-1. Compared with the annual input of nutrients by precipitation, the dust accounted for 10% or less of Ca, Mg and K but approximately 20%–40% of P. The input of nutrients by dust was only valid for areas with vegetation, because in areas with none or sparse vegetation, loss of soil due to wind erosion and hereby loss of nutrients might be significant. In farmland areas with bare and vegetated fields there seemed to be an internal redistribution of the nutrients and not a net gain of nutrients from outside the area(long-range transported dust). The input of P by dust might be of some importance in the traditional shifting cultivation systems, while the inputs of other three nutrients of Ca, Mg and K were so low that they must be considered insignificant. In the intensive agriculture systems with huge inputs of manures and fertilizers the nutrient input by dust is insignificant and could be neglected.展开更多
基金supported by the National Natural Science Foundation of China(No.41473068)supported by China Postdoctoral Science Foundation(No.2022M722667)。
文摘Fertilization or atmospheric deposition of nitrogen(N)and phosphorus(P)to terrestrial ecosystems can alter soil N(P)availability and the nature of nutrient limitation for plant growth.Changing the allocation of leaf P fractions is potentially an adaptive strategy for plants to cope with soil N(P)availability and nutrient-limiting conditions.However,the impact of the interactions between imbalanced anthropogenic N and P inputs on the concentrations and allocation proportions of leaf P fractions in forest woody plants remains elusive.We conducted a metaanalysis of data about the concentrations and allocation proportions of leaf P fractions,specifically associated with individual and combined additions of N and P in evergreen forests,the dominant vegetation type in southern China where the primary productivity is usually considered limited by P.This assessment allowed us to quantitatively evaluate the effects of N and P additions alone and interactively on leaf P allocation and use strategies.Nitrogen addition(exacerbating P limitation)reduced the concentrations of leaf total P and different leaf P fractions.Nitrogen addition reduced the allocation to leaf metabolic P but increased the allocation to other fractions,while P addition showed opposite trends.The simultaneous additions of N and P showed an antagonistic(mutual suppression)effect on the concentrations of leaf P fractions,but an additive(summary)effect on the allocation proportions of leaf P fractions.These results highlight the importance of strategies of leaf P fraction allocation in forest plants under changes in environmental nutrient availability.Importantly,our study identified critical interactions associated with combined N and P inputs that affect leaf P fractions,thus aiding in predicting plant acclimation strategies in the context of intensifying and imbalanced anthropogenic nutrient inputs.
基金the National Natural Science Foundation of China under contract No.41890853the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0404+3 种基金the Science&Technology Basic Resources Investigation Program of China under contract No.2018FY100105the Fund of Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences under contract No.ISEE2018ZD02the National Key Basic Research Program of China(973 Program)under contract No.2015CB452904the Development Project of China under contract Nos2017YFC0506302 and 2016YFC0502805。
文摘Planktonic metabolism plays an important role in affecting the energy transportation and carbon cycle of the marine ecosystem.However,its regulation mechanism remains unclear under the continuously exogenous nutrient inputs in nearshore waters.In this study,a mesocosm experiment was conducted in a semi-enclosed bay,the Daya Bay,to explore the responses of plankton metabolic balance and community structure to a concentration gradient of daily nitrogen and phosphorus inputs.The results showed that nutrient enrichments promoted phytoplankton biomass,total primary production,and community respiration,and the promoting effect enhanced alongwith the increase of nutrient concentration.However,the net community production fluctuated more violently between autotrophic and heterotrophic with the increase of nutrient inputs and tended to be more heterotrophic from the 5 th day to the 10 th day of the experiment.In addition,the daily flux of nitrogen and phosphorus,2μmol/(L·d)and 0.066μmol/(L·d),respectively,could be regarded as a potential threshold for ecosystem stability and health,since most of the ecological characteristics related to plankton structure and function have undergone significant changes when the nutrient level is higher than that.In the nearshore enclosed or semi-enclosed waters,nutrient from continuous terrigenous input is likely to be concentrated and exceed this level,indicating the ecological risks due to the metabolic unbalance and the deterioration of plankton community structure.
文摘为定量化设施果类蔬菜养分投入,实现设施果蔬优质高产、绿色高效生产,本研究以山东省典型设施果类蔬菜为研究对象,基于通过农户调研与土壤样品采集测定收集的数据,结合对现有文献的综述,使用生命周期评价方法,系统分析研究区域设施果类蔬菜生产的施肥现状、土壤养分状况和环境代价及其相关关系。结果表明:山东省主栽设施果类蔬菜养分投入量高,设施番茄、黄瓜、辣椒、茄子的氮(以N计)、磷(以P2O5计)、钾(以K2O计)投入量平均达到743、600、740 kg·hm^(-2),施肥变异系数较大(CV=30.3%~43.9%),大量的肥料投入造成了较高的养分盈余,进而导致表层土壤(0~30 cm)养分含量显著升高,同时导致了较高的环境代价。设施果类蔬菜的单位面积上活性氮损失、温室气体排放、富营养化效应和酸化效应均以黄瓜生产系统最高,分别达225 kg·hm^(-2)、10058 kg CO_(2e)·hm^(-2)、124 kg PO_(4e)·hm^(-2)和63.4 kg SO_(2e)·hm^(-2),其次是茄子、番茄和辣椒。氮素盈余是导致活性氮损失的最主要因素,氮、磷、钾肥料的生产过程和施用过程是设施果类蔬菜温室气体排放、富营养化效应和酸化效应的主要贡献因子,贡献率高达80%以上。因此,为保证设施果类蔬菜产业绿色优质高质量发展,应通过优化设施蔬菜养分资源综合管理策略来减少养分盈余、降低环境代价。
基金supported by the Danida-Enreca project "Ecological Laboratory" of the University of Ghana, Legon, Accra, Ghana
文摘In order to measure dust's nutrient input on farmland in different agro-ecological zones, Harmattan dust was sampled by mats with plastic straw in Ghana between 2002–2006. The inputs of total nutrients by Harmattan dust in Ghana per Harmattan period were about 1–2 kg Ca ha-1, 0.5–2 kg K ha-1, 0.5–1.5 kg Mg ha-1and less than 0.5 kg P ha-1. Compared with the annual input of nutrients by precipitation, the dust accounted for 10% or less of Ca, Mg and K but approximately 20%–40% of P. The input of nutrients by dust was only valid for areas with vegetation, because in areas with none or sparse vegetation, loss of soil due to wind erosion and hereby loss of nutrients might be significant. In farmland areas with bare and vegetated fields there seemed to be an internal redistribution of the nutrients and not a net gain of nutrients from outside the area(long-range transported dust). The input of P by dust might be of some importance in the traditional shifting cultivation systems, while the inputs of other three nutrients of Ca, Mg and K were so low that they must be considered insignificant. In the intensive agriculture systems with huge inputs of manures and fertilizers the nutrient input by dust is insignificant and could be neglected.
