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In situ Assemblies of Bacteria and nutrient dynamics in Response to an Ecosystem Engineer,Marine Clam Scapharca subcrenata,in the Sediment of an Aquaculture Bioremediation System

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Journal of Ocean University of China 2020年第6期19卷 1447-1460页

作者： NICHOLAUS Regan LUKWAMBE Betina YANG Wen ZHU Jinyong ZHENG Zhongming School of Marine Sciences Ningbo UniversityNingbo 315832China Department of Natural Sciences Mbeya University of Science and TechnologyMbeya 53000Tanzania Department of Food Science and Technology University of Dar es SalaamDar es Salaam 35091Tanzania

The relationships between nutrient dynamics,microbial community,and macrofauna are important in bioremediation systems.In this study,we examined the effects of marine clam Scapharca subcrenata sedimentary activities on the microbial assemblages,benthic nutrient chemistry,and its subsequent remediation impacts on organic effluent in the sediment of an aquaculture wastewater bioremediation system.The results showed that microbial community composition differed significantly in the clam area(ANOSIM,R=0.707,P=0.037).Pyrosequencing of bacterial 16S rRNA gene revealed a total of 48 unique phyla,79 classes,107 orders,197 families,and 321 genera amongst all samples.The most dominant bacterial assemblages were Proteobacteria,Bacteroidetes,Acidobacteria,Firmicutes,Verrucomicrobia,and Actinobacteria,with Bacteroidetes and Firmicutes significantly higher in all treatment samples than control(Pnutrient flux rates from the sediments into the water(treatment group)were 51%(ammonium),88%(nitrate),77%(nitrite)and 45%(phosphate)higher,relative to the control implying increased mineralization,degradability,and mobility of the benthic nutrients.Similarly,significantly increased oxygen consumption rates were evident in the clam area signifying improved oxygen distribution within the sediment.The organic effluent contents associated with total-organic matter,carbon,nitrogen,and,phosphate were lower among the clam treatments relative to the control.Our results describe the potential roles and mechanisms contributed by marine bivalve S.subcrenata on benthic-bacterial-community assembly,nutrient balance,and effluent reduction in the sediments of aquaculture wastewaters bioremediation system.

关键词： Scapharca subcrenata effluents bioturbation:sediment chemistry bioremediation nutrient dynamics

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THE SEASONAL dynamics OF nutrient CONTENTS IN MANCHURIA ASH-DAHURIAN LARCH MIXED STAND

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Journal of Northeast Forestry University 1995年第3期6卷 105-108页

作者：国庆喜 Northeast forestry university Harbin P. R. of China

The yield increasing mechanism of the manchurian ash (Fraxinus mandchurica) and dahurian larch(Larix gmelini) mixed stand was studied on nutrition status of soil and leaves. The results showed that nutrient contents of leaves and contents of the available nutrients of soil in the mixed and pure stands varied with seasons of the year. The available phosphorus contentS of the soil in the larch belt were much higher than those in the manchurian ash belt during growhg season, with the highest value of 3.5 mg/100g, 2~3 times of the latter. The nitrogen contents of leaves of the manchurian ash trees nearest from dahurian larch belt wer 12.7%~80.8% higher than those of its pure stand, and phosphorus 13.4%~140. 8%. The different uptake thythm of the nutrients modified the interspecific competition. The general conclusion is that the high contents of available phosphorus of the soil in dahurian larch belt improved the growing condition of nearby manhurian ash trees.

关键词： Mixed stand Manchurian ash nutrient dynamics Dahurian larch

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Application of an optical nitrate profiler to high-and low-turbidity coastal shelf waters

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Acta Oceanologica Sinica 2023年第1期42卷 103-108页

作者： Yanpei Zhuang Yangjie Li Xizhen Liu Shichao Tian Bin Wang Zhongqiang Ji Haiyan Jin Jianfang Chen Polar and Marine Research Institute Jimei UniversityXiamen361000China Key Laboratory of Marine Ecosystem dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China Marine Monitoring and Forecasting Center of Zhejiang Province Hangzhou310000China Institute for Geology University of HamburgHamburg20000Germany State Key Laboratory of Satellite Ocean Environment dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China

Here,we report the results of high-resolution nitrate measurements using an optical nitrate profiler(in situ ultraviolet spectrophotometer,ISUS)along transect across a high-turbidity shelf(East China Sea)and a low-turbidity shelf(Chukchi Sea).The ISUS-measured nitrate concentrations closely reproduced the results measured by conventional bottle methods in low-turbidity waters.However,for high-turbidity waters of the East China Sea(salinitynutrient dynamics on continental shelves.

关键词： high-resolution nitrate measurements in situ ultraviolet spectrophotometer(ISUS) nutrient dynamics nitracline East China Sea Chukchi Sea

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Litter decomposition and nutrient release for two tropical N-fixing species in Rio de Janeiro,Brazil

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Journal of Forestry Research 2022年第2期33卷 487-496页

作者： David Pessanha Siqueira Giovanna Campos Mamede Weiss de Carvalho JoséGabriel de Souza Silva Marcos Vinicius Winckler Caldeira Deborah Guerra Barroso Laboratório de Fitotecnia Universidade Estadual do Norte Fluminense Darcy RibeiroAvenida Alberto Lamego2000Campos dos GoytacazesRio de JaneiroBrazil Departamento de Ciências Florestais e da Madeira Universidade Federal do Espírito SantoAvenida Governador Lindenberg316Jerônimo MonteiroEspírito SantoBrazil Department of Geosciences and Natural Resources Management University of CopenhagenRolighedsvej 23Frederisksberg CDenmark

Litter production and decomposition are critical to forest productivity,nutrient cycling,and carbon seques-tration in tropical woody ecosystems.However,nutrient release and leaf litter stoichiometry in tropical legume tree plantations over the long term after outplanting are poorly understood or even unknown.Toward improving our under-standing of the pattern of changes in the decomposition of N-fixing leaf litters and their possible impact on carbon stor-age,we measured litter production,mass loss and nutrient release for 240 d during litter decomposition for two tropical legume tree species(Plathymenia reticulata and Hymenaea courbaril),in Rio de Janeiro,Brazil.Litter production for P.reticulata was 5.689 kg ha^(−1) a^(−1) and 3.231 kg ha^(−1) a^(−1) for H.courbaril.The patterns of mass loss rates were similar;however,nutrient release was greater for P.reticulata,while H.courbaril showed immobilization of nutrients,especially for N,which increased by almost 20%in the early phase of decomposition followed by gradual release.Litter from the N-fixing species did differ in nutrient chemistries over time,which was not surprising given that initial nutrient concentrations varied broadly,except for C and P.Most of the nutrient concentrations increased as the remaining litter mass decreased in both species,except for C and K.The C:N and N:P ratios differed between the species,but N:P did not correlate to mass loss.Both species had N-rich leaves,but P.reticulata decomposition was very likely P-limited,while H.courbaril seemed to be co-limited by N and P.The results showed different patterns in nutrient release and the stoichi-ometry involved in the decomposition dynamics of the two tropical N-fixing species,even though they have similar litter decay rates.Both species,but especially P.reticulata,may help re-establish nutrient cycling in disturbed ecosystems.

关键词： nutrient dynamics Legume species Litter chemistry Ecological stoichiometry Tropical forest

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Ecological implications of twentieth century reforestation programs for the urban forests of São Paulo, Brazil: a study based on litterfall and nutrient cycling

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Ecological Processes 2021年第1期10卷 367-379页

作者： Maurício Lamano Ferreira Marcelo Ferreira Barbosa Eduardo Pereira Cabral Gomes Ana Paula Branco do Nascimento Edgar Fernando de Luca Karina Gonçalves da Silva Ulisses Bezerra França Plínio Barbosa de Camargo Raffaele Lafortezza Master’s Program in Health Promotion Adventist University of São PauloSão PauloSPBrazil. Master’s Program in Geoenvironmental Analysis University of GuarulhosGuarulhosSPBrazil. Department of Health Faculty of Biological ScienceUniversity Nove de Julho(UNINOVE)São PauloSPBrazil. Institute of Botany(IBT/SP) São PauloSPBrazil. Department of Civil Engineering São Judas Tadeu UniversitySão PauloSPBrazil. Institute of Forestry(IF/SP) São PauloSPBrazil. Centro de Energia Nuclear na Agricultura(CENA/USP) University of São PauloPiracicabaSPBrazil. Prefeitura da cidade de São Paulo(Secretaria do Verde e Meio Ambiente) São PauloSPBrazil Department of Agricultural and Environmental Sciences University of Bari Aldo MoroBariItaly. Department of Geography The University of Hong KongCentennial CampusPokfulam RoadHong KongHong Kong.

The focus of this study was to investigate the wide use of Eucalyptus spp.,an exotic plant with high allelopathic ability,in the reforestation programs of urban parks in São Paulo City,Brazil,over the last century.To understand the implications of using Eucalyptus spp.in the city’s parks,this study aimed to compare nutrient cycling and litter decomposition between a mixed composition of litter(i.e.,native and exotic species)and the litter of a single species(i.e.,Eucalyptus).To accomplish this,newly deciduous leaves were collected from two native and two exotic species that are commonly used in the afforestation of São Paulo as well as from Eucalyptus spp.The mixed composition of litter yielded a higher dry mass loss and return of macro-and micronutrients to the forest floor.The decomposition constant(k)values were 0.00322 and 0.00207 g g^(−1) day^(−1) for the mixed composition and Eucalyptus spp.,respectively.The time required for decomposition of 50 and 95%of deciduous material was 215 and 931 days,respectively,and for the mixed litterfall 334 and 1449 days,respectively,for Eucalyptus spp.Therefore,the mixed litter exhibited greater dry mass loss and nutrient cycling in an urban forest of São Paulo City,since dry mass losses as well as speed and amount of nutrients returned to the forest floor were relatively higher compared to Eucalyptus spp.nutrient cycling via Eucalyptus spp.litter was less efficient than mixed composition of litter,demonstrating that reforestation programs carried out in the twentieth century using only one species may have had little success.The results of this work emphasize the fact that in urban reforestation programs the City of São Paulo must consider the environmental and biogeographic characteristics of the species employed and use high levels of biodiversity,since the city lies in a megadiverse biome.

关键词： Tropical forest Exotic species nutrient dynamics Ecosystem functioning

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Root stoichiometric dynamics and homeostasis of invasive species Phyllostachys edulis and native species Cunninghamia lanceolata in a subtropical forest in China

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Journal of Forestry Research 2021年第5期32卷 2001-2010页

作者： Chao Peng Jia Tu Ming Yang Yong Meng Meiqun Li Wensheng Ai Institute of Bamboo Research Hunan Academy of ForestryChangsha 410004Hunan ProvinceP.R.China

The community species abundance and diversity declined with bamboo invasion had been widely reported worldwide.However,the physiological strategies used during root competition between native species and invasive bamboo are poorly understood.To clarify the mechanisms underlying such strategies,the stoichiometric dynamics and homeostasis of nitrogen,phosphorus,organic carbon in root orders of Phyllostachys edulis(I du[=Ⅰ-Pe,years 1 and 2];Ⅱdu[=Ⅱ-Pe,years 3 and 4]),Cunninghamia lanceolata in transition and pure forests were analyzed.With increasing intensity of bamboo invasion,N,P,and C content of C.lanceolata root orders declined,N and P content in P.edulis rhizome orders declined,while C increased,the stoichiometric ratios in mixed forest interface mainly increased,and the stoichiometric differences within native and invasive species root orders narrowed.Meanwhile,the stoichiometric homeostasis index(H)of elements in the same root order and even the same elements in different root orders were not consistent.H of most root orders(except some HP)was greater than 4,the H ranked order wasⅠ-Pe>Cl>Ⅱ-Pe in mixed interfaces,and the N:P ratio of most species root orders was greater than 16,despite being affected by invasion.Our research concluded that the bamboo invasion narrows stoichiometric differences within root orders,and the juvenile bamboo rhizome has a stronger capacity for homeostatic regulation than in adult bamboo and C.lanceolata,which is a key determinant of bamboo invasion success.

关键词： Bamboo invasion Root orders nutrient dynamics Homeostatic regulation coefficient

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Land-Use Change on Soil C and N Stocks in the Humid Savannah Agro-Ecological Zone of Ghana

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Journal of Environmental Protection 2022年第1期13卷 32-68页

作者： Johnny Kofi Awoonor Fowzia Adiyah Bright Fafali Dogbey Soil Genesis Survey and Classification Division CSIR-Soil Research Institute Kumasi Ghana Department of Soil Science and Agrochemistry Hungarian University of Agriculture and Life Sciences G&ouml dö ll&odblac Hungary Department of Soil Resources Management CSIR College of Science and Technology Accra Ghana

Land-use conversion and unsustainable farming practices are degrading native forest ecosystems of Ghana’s humid savannah agro-ecological zone. This study assessed the impact of land-use change on soil C and N stocks in different land-use systems and soil types. A total of eighty (80) composite soil samples at two depths (0 - 20 cm and 20 - 50 cm) were sampled from five land use types (Forest, Woodland savannah, Grassland, Fallow and Cropland) for laboratory analyses. Particle size distribution, bulk density, pH, SOC and TN were determined using standard procedures. Results of the study indicated that C and N stocks were significantly lower in croplands (p 2 value of 0.85 and 0.93 for the 0 - 20 and 20 - 50 cm depth, respectively. Soil C and N stocks in the study area were estimated to be 34.56 kg/m2 and 4.63 kg/m2 for soil types and 26.89 kg/m2 and 3.39 kg/m2 for land use types, respectively for the 0 to 50 cm soil depth. Our findings indicated that the conversion of native forest to arable land has significantly reduced soil C and N stocks in the top 50 cm (0.50 m) soil layer by 50.77% and 47.77%, respectively. Therefore, we conclude that land-use change, soil type, and soil depth influenced soil C and N stocks of land-use systems in the humid savannah agro-ecological zone of Ghana.

关键词： Land Conversion nutrient dynamics Soil C and N Stocks Soil Type Land-Use

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Short-term dynamics of nutrients influenced by upwelling in a small oligotrophic coastal ecosystem,Gan Bay,in the northwest Philippines

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Progress in Natural Science:Materials International 2009年第5期19卷 595-601页

作者： Yanping Xu, Minhan Dai, Weidong Zhai, Dongxing Yuan, Jinwen Liu, Zhenyu Sun, Hua Lin, Jingyu Wu State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

We present a time-series analysis of nutrient and pCO2 (partial pressure of CO2) levels in an oligotrophic coastal ecosystem (Gan Bay), which was likely to be influenced by upwelled subsurface water. Gan Bay is of Currimao Harbor, in the northwest Philippines and is located at the boundary of the South China Sea (SCS). This 42-h time-series observation was conducted in December 2006. In addition to continuous observations of dissolved oxygen (DO) and pCO2, discrete samples were collected at a depth of 5 m every 3 h for measurements of nutrients, including soluble reactive phosphorus (SRP) and inorganic nitrogen (NO3 + NO2 ) in order to examine their dynamics and possible physical and biological controls. We observed remarkably large short-term variations in the surface water, spanning a 10-fold change for SRP (32-330 nM) and from nutrients was driven neither by tidal mixing nor by biological activities, as was suggested by the variations in the total bacterial abundance and chlorophyll a. Instead, our inverse T-S relationship suggested a two end-member mixing process during the observation period. The N:P ratio throughout the observation period was 13.2, which is characteristic of SCS subsurface and deep waters. Moreover, pCO2 was correlated inversely with the sea surface temperature. It is likely, therefore, that an upwelled subsurface cold water with high nutrients, low-temperature and high-pCO2 existed. It should be noted that this upwelled cold water did not appear to impact the entire observation period (approximately 35 h of 42 h), which might suggest an extremely dynamic nature for this upwelled cold water mass.

关键词： Gan Bay South China Sea nutrient dynamics Upwelling

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Effects of Nitrogen Addition on the Mixed Litter Decomposition in Stipa baicalensis Steppe in Inner Mongolia

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American Journal of Plant Sciences 2016年第3期7卷 547-561页

作者： Wenya Li Wenchao Yu Long Bai Hongmei Liu Dianlin Yang Department of Horticulture Shenyang Agricultural University Shenyang China Agro-Environmental Protection Institute Ministry of Agriculture Tianjin China Key Laboratory of Original Agro-Environment Quality of Ministry of Agriculture and Tianjin Key Laboratory of Agro-Environment and Safe-Product Tianjin China

During the past two centuries, global changes (i.e., enhanced nitrogen deposition) have exerted profound effects on ecological processes of steppe ecosystems. We used litterbag method and mixed litters of three different plant species tissues (Stipa baicalensis: Sb, Leymus chinensis: Lc and Artemisia frigid: Af), endemic to Stipa baicalensis Steppe, and measured the mass loss of mixtures over 417 days under the N addition treatment. We studied the effect of N addition (N0: no N addition;N15: 1.5 g N/m2·a;N30: 3.0 g N/m2·a;N50: 5.0 g N/m2·a;N100: 10.0 g N/m2·a;N150: 15.0 g N/m2·a) on the rate of mixed litter decomposition and nutrient dynamics change. The decomposition constant (k) of leaf mixtures was higher than that of root mixtures. The k values of leaf mixed combinations were 0.880 (Sb + Lc), 1.231 (Lc + Af), 1.027 (Sb + Lc + Af), respectively. The k value of stem was 0.806 (Lc + Af) and the root mixed combinations were 0.665 (Sb + Lc), 0.979 (Lc + Af) and 1.164 (Sb + Lc + Af), respectively. The results indicated that N addition had significantly effect on the mixed litter decomposition and nutrient releasing. The rate of plant tissues litter decomposition had different response to N addition. In the context of N addition, litter decomposition rate and nutrient dynamics were changed by synthetic effect of decaying time, specie types and N addition dose. Our findings suggested that prairie plants may adapt to environmental change by adjusting litter quality, thus retaining the stability of the steppe ecosystem.

关键词： Grassland Litter Decomposition Mixed Effect N Addition Mass Loss nutrient dynamics

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