Biblioteca Digital do Instituto Politécnico de Bragança   Instituto Politécnico de Bragança

Biblioteca Digital do IPB >
Escola Superior Agrária >
Biologia e Biotecnologia >
BB - Artigos em Revistas Não Indexados ao ISI >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10198/705

Título: Do distinct water chemistry, reservoir age and disturbance make any difference on phosphatase activity?
Autor: Geraldes, Ana Maria
Boavida, Maria José
Palavras-chave: Alkaline phosphatase
Orthophosphate regeneration
Phytoplankton
Zooplankton
Reservoirs
Issue Date: 2003
Editora: Istituto Italiano di Idrobiologia
Citação: Journal of Limnology. ISSN 1723-8633. 62:2 (2003) p. 163-171
Resumo: Alkaline phosphatase activity was assessed concomitantly with total phosphorus, orthophosphate and phosphomonoester concentrations in two meso-eutrophic reservoirs with distinct age and subjected to different kinds of environmental influence. Differences in conductivity, temperature and pH were found. However, during the study period alkaline phosphatase activity was similar in both reservoirs. Water colour was higher in S. Serrada Reservoir. This fact can be related to (1) reservoir age (2) high internal disturbance (3) large imputs of allochthonous detritus, resulting from the combined effect of grazing, fire and catchment slope. Despite the high water colour recorded in S. Serrada, alkaline phosphatase activity was apparently not inactivated by humic substances. Besides, the obtained results demonstrated that hydrolysis of phosphomonoesters by alkaline phosphatase was not important for orthophosphate regeneration in these reservoirs. Probably orthophosphate was always available to biota. In fact, in the experiments based on Selenastrum capricornutum Printz algal test, similar phytoplankton growth responses were obtained for different phosphorus concentrations. Thus, these results seem to indicate that phosphorus was not a limiting nutrient in either reservoir. Although phosphatase activity was significantly correlated with some phytoplankton genera in both reservoirs, no significant correlations were found between enzyme activity and chlorophyll-a. Significant correlations between phosphatase activity and crustacean zooplankton were only recorded in S. Serrada. In spite of these results there was some indication that the main source of phosphatase might have been bacteria involved in decomposition processes instead of phyto- and zooplankton taxa.
URI: http://hdl.handle.net/10198/705
ISSN: 1723-8633
Appears in Collections:CIMO - Artigos em Revistas Indexados ao ISI
BB - Artigos em Revistas Não Indexados ao ISI

Files in This Item:

File Description SizeFormat
j. of limnology.pdf416,71 kBAdobe PDFView/Open
Statistics
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpaceOrkut
Formato BibTex mendeley Endnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 


  © Instituto Politécnico de Bragança - Biblioteca Digital - Feedback - Statistics
  Estamos no RCAAP Governo Português separator Ministério da Educação e Ciência   Fundação para a Ciência e a Tecnologia

Financiado por:

POS_C UE