Significance of plankton respiration for productivity in coastal ecosystems
Başlık çevirisi mevcut değil.
- Tez No: 401684
- Danışmanlar: PROF. STIIG MARKAGER, DR. JORGEN L. S. HANSEN
- Tez Türü: Doktora
- Konular: Biyoteknoloji, Biotechnology
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2015
- Dil: İngilizce
- Üniversite: Aarhus Universitet
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Biyolojik Bilimler Ana Bilim Dalı
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 85
Özet
Özet yok.
Özet (Çeviri)
Although primary production measurements are routine in Danish National Aquatic Monitoring and Assessment Program (DNAMAP), respiration measurements are not included and hence only a few studies on this subject have been conducted in Danish estuaries. Therefore Paper I aimed to document seasonal and ecosystem specifi c patterns of respiration and discuss unknowns of pelagic respiration including net community production in Danish estuaries. Seasonal cycles of pelagic primary production, community respiration and net community production were investigated in surface waters of two Danish estuaries, Roskilde Fjord (RF) and the Great Belt (GB) over one year. We found three to eight times higher inorganic nutrient concentrations in RF than in GB but this diff erence was only translated into two to three times higher biomasses and volumetric rates and the biomass-specifi c rates were similar for the two sites. Both photosynthesis rates and community respiration rates followed a seasonal cycle of water temperature and Chlorophyll a concentration. Hence a nonlinear model was defi ned for community respiration based on Chlorophyll a and temperature for both stations. Temperature sensitivity of the processes, expressed in terms of a Q10 value, were calculated. High nutrient concentrations in RF resulted in a higher average Q10 value (2.7) for photosynthesis and respiration than in GB (1.7). It is concluded that, in more oligotrophic systems the positive eff ect of higher temperatures during summer will be counteracted by more pronounced nutrient limitation which confi nes the biomass specifi c process. Thus Q10 values in seasonal studies could be aff ected by the seasonality in nutrient availability and in this case it would often be underestimated. Contribution of bacteria to community respiration was found to be 28% and 62%, in RF and GB respectively. Despite the uncertainty in bacterial respiration (BR) estimates there were indications of increasing rates with decreasing phytoplankton biomass which could also explain the diff erence in BR between two sites. Areal net community production (NCP) calculations in the surface waters of two stations support the hypothesis that 14C-method measures something close to net primary production even for 2 h incubations. Despite similar values for primary production (14C uptake; ~144 g C m-2 y-1) in both stations, NCP of the shallow and nutrient rich RF was two times higher (99 g C m-2 y-1) than in GB (45 g C m-2 y-1). This study overall emphasizes necessity of coupled photosynthesis and respiration measurements in order to understand productivity and carbon cycling in marine waters. In Paper II, we investigated the relationship between photosynthetic activity and dark respiration in three marine phytoplankton species (Heterocapsa rotundata, Rhodomonas salina and Thalassiosira weissfl ogii). There has been a longstanding question of whether phytoplankton dark respiration is aff ected by previous photosynthesis or not. In this study experiments were designed to quantify eff ects of increasing light doses (irradiance × duration) on dark respiration. Dark respiration rates were measured after 1 to 3 hours of light exposure in 12 bottles where incubation irradiances ranged from 0 to 600 μmol photons m-1 s-1. We found that the dark respiration increased after light exposures (both irradiance and duration) in all exponentially growing cultures. This relationship could be described by a linear model for all species relating respiration to the previous accumulated photosynthetic activity. Model results suggested that studied species have the same carbon turnover capacity although the diatom T. weissfl ogii was able to use available carbon more effi ciently than the cryptophyte R. salina and the dinofl agellate H. rotundata. The maximum respiration (Rmax) was estimated by a non-linear model from light dose and accumulated photosynthetic activity. Although species had variable Rmax and light-saturated gross photosynthesis (Pg max), we found a similar Rmax : Pg max ratio of ~0.12. Overall, this study suggests a diel periodicity of phytoplankton respiration depending on intracellular substrate availability and that respiration rates are higher during sunset than during sunrise in aquatic systems. Respiration rates in aquatic systems have often been assumed to be constant during night. As we have suggested in Paper II phytoplankton respiration rates could vary over time and in Paper III, we investigated the time course of respiration rates in phytoplankton cultures, natural seawater and at the aquatic ecosystem level. We determined respiration rates from measurements of oxygen consumption over time, using two diff erent experimental techniques; continuous measurement of oxygen concentration by non-invasive optodes in bottles incubated in dark and in situ measurement of oxygen by optodes freely deployed in the water column at night. Additionally, we investigated eff ects of incubation time on respiration rates in bottle incubations. We fi tted two diff erent models to the oxygen data to explain the variability. We observed three diff erent respiration patterns; a constant, a decreasing, an increasing or a combination of these. Constant respiration rates were observed widely from the data derived from estuaries with bottle incubations (
Benzer Tezler
- Kıyı yerleşimlerinde kentsel atıksu arıtma tesislerinin bütüncül bir yaklaşımla planlanması
Planning of urban wastewater treatment plants in the coastal areas with integrated approach
GÜLSEN AVAZ
Doktora
Türkçe
2019
Çevre MühendisliğiGebze Teknik ÜniversitesiÇevre Mühendisliği Ana Bilim Dalı
PROF. DR. MELEK ÖZKAN
- Samsun kıyı bölgesi kopepoda faunasının kalitatif ve kantitatif araştırılması
A qualitative and quantitative study on the copepod fauna of littoral zone of Samsun
EDA DENİZ
Yüksek Lisans
Türkçe
2009
BiyolojiOndokuz Mayıs ÜniversitesiBiyoloji Ana Bilim Dalı
PROF. DR. ARİF GÖNÜLOL
- Ege Denizi'nin farklı bölgelerindeki plankton örneklerinde Po-210 birikiminin incelenmesi
Investigations of Po-210 accumulation in plankton samples from different zones of Aegean Sea
FATİH ARSLAN
Yüksek Lisans
Türkçe
2005
Nükleer MühendislikEge ÜniversitesiNükleer Bilimler Ana Bilim Dalı
DOÇ.DR. AYSUN UĞUR
- Bölgesel ölçekte klorofil-a konsantrasyonunun belirlenmesinde sentınel-3 olcı verilerinin kullanım olanaklarının araştırılması
Investigation of opportunity to use sentinel-3 olci data in the determination of chlorophyll-a concentration at regional scale
BAŞAK DEMİR
Yüksek Lisans
Türkçe
2022
Deniz Bilimleriİstanbul Teknik Üniversitesiİletişim Sistemleri Ana Bilim Dalı
PROF. DR. ŞİNASİ KAYA
- Karacaören I baraj gölü (Burdur) planktonunun taksonomik ve ekolojik olarak incelenmesi
Taxonomical and ecological studies on the plankton of Karacaören I dam lake (Burdur)
İSKENDER GÜLLE
Doktora
Türkçe
2005
Su ÜrünleriSüleyman Demirel ÜniversitesiSu Ürünleri Temel Bilimleri Ana Bilim Dalı
PROF.DR. OSMAN ERTAN