Algal Growth and Primary Productivity in a Thermal Stream

1968 ◽  
Vol 25 (10) ◽  
pp. 2037-2058 ◽  
Author(s):  
John G. Stockner
Keyword(s):  
Primary Production ◽  
Growth Rates ◽  
Hot Springs ◽  
Hot Spring ◽  
Morphological Changes ◽  
Gross Primary Production ◽  
Standing Stock ◽  
Algal Species ◽  
Algal Growth ◽  
Algal Mat

Estimates of primary production and respiration of cyanophycean algal species growing in the run-off stream of a hot spring (37 C) were obtained throughout 1966 using the diurnal oxygen curve technique. Rates of gross primary production were slightly higher than published values from other aquatic ecosystems, but were less than recent estimates from hot springs in Yellowstone and Mount Lassen National Parks using the C14 uptake method. Production/respiration ratios were calculated and ranged from 1.1 to 5.0. The effect of photosynthesis on the ionic concentration of influent and effluent water was noted, together with morphological changes in the algal mat as the growing season progressed. Changes in algal standing stock were studied in 1964 and 1965, together with growth rates from denuded areas by two methods of harvest. In both years the most rapid growth was recorded in May and June, whereas during the winter months growth was negligible. Maximum values of primary production in May and June 1966 coincided with these maximum growth periods. Significant differences in growth rates between years were thought to be due to several factors; most notably, harvest methods and auto-inhibitory toxins produced by layers of senescent cells composing the "mature" algal mat. Energy losses due to algal export and grazing are discussed in relation to the dynamics of the mat, and an annual energy budget is derived from estimates obtained in 1966.

Pharmaceuticals and personal care products alter growth and function in lentic biofilms

2015 ◽  
Vol 12 (3) ◽  
pp. 301 ◽  
Author(s):  
Lawton Shaw ◽  
Chuyen Phung ◽  
Michael Grace
Keyword(s):  
Primary Production ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Personal Care Products ◽  
Algal Growth ◽  
Biologically Active ◽  
Community Respiration ◽  
Personal Care ◽  
Ecological Processes ◽  
And Function

Environmental context Pharmaceuticals and personal care products are routinely found in waters discharged from treatment plants and in surrounding aquatic ecosystems. Despite the widespread occurrence of these biologically active agents, there is limited understanding of their potential effects on key ecosystem processes such as primary production, ecosystem respiration and algal growth. This paper examines the effects of five common pharmaceuticals on the rates of these fundamental processes. Abstract Pharmaceutical diffusing substrates were used to study in situ responses of aquatic biofilms in an urbanised lentic ecosystem to five pharmaceutical and personal care products (PPCPs; caffeine, cimetidine, ciprofloxacin, diphenhydramine and metformin). The pharmaceutical diffusing substrates consisted of porous biofilm substrates placed atop a mass of agar amended with 2.5mM of the PPCP compound of interest. Over 21 days, biofilms growing on the substrata were exposed to slow diffusion of the PPCP through the agar and porous substrate. Algal biomass was suppressed by exposure to diphenhydramine (–81%) and ciprofloxacin (–50%). Gross primary production was completely suppressed by diphenhydramine exposure but stimulated by caffeine (+39%) and cimetidine (+46%). For heterotroph biofilms, community respiration was suppressed by exposure to diphenhydramine (–24%). To characterise PPCP exposure, rates of diffusion from the pharmaceutical diffusing substrates were measured at 10, 20 and 30°C. Diffusion was Fickian for all compounds and all temperatures. Diffusion coefficients, D, were in the range 1.5×10–10 to 1.1×10–9m2s–1. From diffusion data, average release rates over 21 days were typically 30–50ngmin–1cm–2 at 20°C. The results show that PPCPs can dramatically affect rates of key ecological processes, and the relationship between release rate and ambient concentration of PPCPs is discussed.

Periphyton response to long-term nutrient enrichment in a shaded headwater stream

2005 ◽  
Vol 62 (9) ◽  
pp. 2033-2045 ◽  
Author(s):  
Jennifer L Greenwood ◽  
Amy D Rosemond
Keyword(s):  
Growth Rates ◽  
Nutrient Enrichment ◽  
Algal Species ◽  
Light Availability ◽  
Algal Growth ◽  
Detectable Effect ◽  
Long Term Effects ◽  
Tree Canopies ◽  
Periphyton Biomass

We maintained elevated but moderate concentrations of nitrogen and phosphorus continuously for 2 years in a heavily shaded headwater stream and compared effects on stream periphyton with a reference stream. Both streams were sampled for 1 year before treatment. Some measures of periphyton biomass (ash-free dry mass and chlorophyll a) responded positively to enrichment. Increased chlorophyll a was likely a result of higher chlorophyll per cell, as total algal biovolume did not change with enrichment. These differences were greatest during high-light months (November-May), when cellular growth rates (a proxy for production) were also highest with enrichment. Algal assemblages were dominated by diatoms and remained similar between the treatment and reference streams throughout the enrichment period. Although nutrients stimulated algal growth rates, the long-term effects of nutrient addition on periphyton biomass were small in magnitude compared with other published values and were potentially suppressed by light availability and invertebrate consumption. These and other factors may have also been important in limiting the algal species pool and thus a taxonomic response to enrichment. Our results indicate that in headwater streams with intact tree canopies, chronic nutrient enrichment at moderate concentrations may have little detectable effect on benthic algal composition or periphyton biomass. Although nutrients stimulated algal growth rates, the long-term effects of nutrient addition on periphyton biomass were small in magnitude compared with other published values and were potentially suppressed by light availability and invertebrate consumption. These and other factors may have also been important in limiting the algal species pool and thus a taxonomic response to enrichment. Our results indicate that in headwater streams with intact tree canopies, chronic nutrient enrichment at moderate concentrations may have little detectable effect on benthic algal composition or periphyton biomass.

scholarly journals Estimation of crop gross primary production (GPP): fAPARchl versus MOD15A2 FPAR

2014 ◽  
Vol 153 ◽  
pp. 1-6 ◽  
Author(s):  
Qingyuan Zhang ◽  
Yen-Ben Cheng ◽  
Alexei I. Lyapustin ◽  
Yujie Wang ◽  
Feng Gao ◽  
...  
Keyword(s):  
Primary Production ◽  
Gross Primary Production

scholarly journals Origin of the low-medium temperature hot springs around Nanjing, China

2021 ◽  
Vol 13 (1) ◽  
pp. 820-834
Author(s):  
Jun Ma ◽  
Zhifang Zhou
Keyword(s):  
Hot Springs ◽  
Hot Spring ◽  
Hot Water ◽  
Geothermal Water ◽  
Geological Condition ◽  
Medium Temperature ◽  
Rock Interaction ◽  
Karst Landform ◽  
Karst Landforms ◽  
Development And Management

Abstract The exploration of the origin of hot spring is the basis of its development and utilization. There are many low-medium temperature hot springs in Nanjing and its surrounding karst landform areas, such as the Tangshan, Tangquan, Lunshan, and Xiangquan hot springs. This article discusses the origin characters of the Lunshan hot spring with geological condition analysis, hydrogeochemical data, and isotope data. The results show that the hot water is SO4–Ca type in Lunshan area, and the cation content of SO4 is high, which are related to the deep hydrogeological conditions of the circulation in the limestone. Carbonate and anhydrite dissolutions occur in the groundwater circulation process, and they also dominate the water–rock interaction processes in the geothermal reservoir of Lunshan. The hot water rising channels are deeply affected by the NW and SN faults. Schematic diagrams of the conceptual model of the geothermal water circulation in Lunshan are plotted. The origin of Tangshan, Tangquan, and Xiangquan hot springs are similar to the Lunshan hot spring. In general, the geothermal water in karst landforms around Nanjing mainly runs through the carbonate rock area and is exposed near the core of the anticlinal structure of karst strata, forming SO4–Ca/SO4–Ca–Mg type hot spring with the water temperature less than 60°C. The characters of the hot springs around Nanjing are similar, which are helpful for the further research, development, and management of the geothermal water resources in this region.

scholarly journals Radon Activity Concentrations in Natural Hot Spring Water: Dose Assessment and Health Perspective

2021 ◽  
Vol 18 (3) ◽  
pp. 920
Author(s):  
Eka Djatnika Nugraha ◽  
Masahiro Hosoda ◽  
June Mellawati ◽  
Untara Untara ◽  
Ilsa Rosianna ◽  
...  
Keyword(s):  
Public Health ◽  
Effective Dose ◽  
Radiation Protection ◽  
Water Samples ◽  
Hot Springs ◽  
Hot Spring ◽  
Annual Effective Dose ◽  
Spring Water ◽  
Dose Assessment ◽  
West Java

The world community has long used natural hot springs for tourist and medicinal purposes. In Indonesia, the province of West Java, which is naturally surrounded by volcanoes, is the main destination for hot spring tourism. This paper is the first report on radon measurements in tourism natural hot spring water in Indonesia as part of radiation protection for public health. The purpose of this paper is to study the contribution of radon doses from natural hot spring water and thereby facilitate radiation protection for public health. A total of 18 water samples were measured with an electrostatic collection type radon monitor (RAD7, Durridge Co., USA). The concentration of radon in natural hot spring water samples in the West Java region, Indonesia ranges from 0.26 to 31 Bq L−1. An estimate of the annual effective dose in the natural hot spring water area ranges from 0.51 to 0.71 mSv with a mean of 0.60 mSv for workers. Meanwhile, the annual effective dose for the public ranges from 0.10 to 0.14 mSv with an average of 0.12 mSv. This value is within the range of the average committed effective dose from inhalation and terrestrial radiation for the general public, 1.7 mSv annually.

scholarly journals Soil drying weakens the positive effect of climate factors on global gross primary production

2021 ◽  
Vol 129 ◽  
pp. 107953
Author(s):  
Huan Chen ◽  
Xiaoyong Bai ◽  
Yangbing Li ◽  
Qin Li ◽  
Luhua Wu ◽  
...  
Keyword(s):  
Primary Production ◽  
Gross Primary Production ◽  
Soil Drying ◽  
Climate Factors ◽  
Positive Effect

scholarly journals Can vegetation index track the interannual variation in gross primary production of temperate deciduous forests?

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Fan Liu ◽  
Chuankuan Wang ◽  
Xingchang Wang
Keyword(s):  
Primary Production ◽  
Vegetation Index ◽  
Near Infrared ◽  
Deciduous Forest ◽  
Gross Primary Production ◽  
Growing Season ◽  
Temperate Deciduous Forest ◽  
Near Infrared Reflectance ◽  
Modis Ndvi ◽  
Temperate Deciduous

Abstract Background Vegetation indices (VIs) by remote sensing are widely used as simple proxies of the gross primary production (GPP) of vegetation, but their performances in capturing the inter-annual variation (IAV) in GPP remain uncertain. Methods We evaluated the performances of various VIs in tracking the IAV in GPP estimated by eddy covariance in a temperate deciduous forest of Northeast China. The VIs assessed included the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), and the near-infrared reflectance of vegetation (NIRv) obtained from tower-radiometers (broadband) and the Moderate Resolution Imaging Spectroradiometer (MODIS), respectively. Results We found that 25%–35% amplitude of the broadband EVI tracked the start of growing season derived by GPP (R2: 0.56–0.60, bias < 4 d), while 45% (or 50%) amplitudes of broadband (or MODIS) NDVI represented the end of growing season estimated by GPP (R2: 0.58–0.67, bias < 3 d). However, all the VIs failed to characterize the summer peaks of GPP. The growing-season integrals but not averaged values of the broadband NDVI, MODIS NIRv and EVI were robust surrogates of the IAV in GPP (R2: 0.40–0.67). Conclusion These findings illustrate that specific VIs are effective only to capture the GPP phenology but not the GPP peak, while the integral VIs have the potential to mirror the IAV in GPP.

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