Effects of physical characteristics and nutrient ratios (N:P:Si) on diatoms and cyanobacteria in freshwater: a meta-analysis
- Authors
- Albarrac?n Rodas, Marco Eugenio
- Format
- MasterThesis
- Status
- publishedVersion
- Description
Eutrophication and cyanobacteria blooms is a major environmental and water resource problem, and the traditional management involves reduction of nutrient loads (i.e. N and P) with little or without consideration of the effect of hydraulic residence time (HRT) and nutrient ratios (N:P, Si:P, and Si:N) on phytoplankton biomass and community structure. I have investigated using a meta-analysis, the relationships between physical factors and nutrient ratios (N:P:Si) that explain the phytoplankton biomass and the community composition in freshwater inland lakes and reservoirs worldwide. Additionally, patterns of the influence of nutrient ratios on the phytoplankton community structure, and also similarities between different climate zones were investigated. HRT and N:P ratio comes up as an important explanatory variable with cyanobacteria. Additionally, at high levels of Chl a the relative abundance of Cyanophyta was higher, while the relative abundance of Bacillariophyta was lower. Without limitation of nutrient ratios, diatoms is the dominant group, whilst cyanobacteria dominate at N limitation conditions. Tropical lakes and reservoirs show a dissimilarity with both temperate and polar water bodies; on the other hand, polar lakes and temperate lakes and reservoirs result similar. I conclude that human interventions on water, such as dams construction and nutrient loads, are creating conditions favorable for cyanobacteria across wide spatial scales. The mechanism of this could be through altering Si:P and Si:N due the retention/export of Si, but also by increasing the temperature of the epilimnetic water in reservoirs and decreasing the N:P ratio through land use change. More studies to assess the HRT with phytoplankton community structure along with nutrient ratios are necessary in front of a a global warming future and more dam constructions.
- Publication Year
- 2014
- Language
- eng
- Topic
- EUTROPHICATION
CYANOBACTERIA
SILICA
NUTRIENT RATIOS
- Repository
- Repositorio SENESCYT
- Rights
- openAccess
- License
- openAccess