Landscape variables influencing nutrients and phytoplankton communities in Boreal Plain lakes of northern Alberta: a comparison of wetland- and upland-dominated catchments

2001 ◽  
Vol 58 (7) ◽  
pp. 1286-1299 ◽  
Author(s):  
E E Prepas ◽  
D Planas ◽  
J J Gibson ◽  
D H Vitt ◽  
T D Prowse ◽  
...  
Keyword(s):  
Drainage Basin ◽  
Lake Volume ◽  
Headwater Lakes ◽  
Phytoplankton Communities ◽  
Effective Drainage ◽  
Northern Alberta ◽  
Basin Area ◽  
Wetland Cover ◽  
Topographic Relief

A review of headwater lakes in undisturbed watersheds on the Boreal Plain, with indirect gradient analyses of chemical data, indicated a clear separation between those in wetland-dominated watersheds (57–100% wetland with variable proportions of bog, fen, swamp, and marsh cover) and those in upland-dominated watersheds (0–44% wetland cover). In the former, percentage wetland cover in the watershed was positively correlated with total phosphorus (TP, r2 = 0.78, primarily bog), total nitrogen (TN, r2 = 0.50), and dissolved organic carbon (DOC, r2 = 0.74) concentrations. Rich fens appeared to sequester both TP and TN. In upland-dominated lakes, the ratio of catchment area to lake volume (CA/LV) was the strongest watershed correlate of TP concentration (r2 = 0.56), whereas most limnetic nitrogen and DOC were generated in situ. Colour concentration, being highest in wetland lakes, was correlated with the ratio of isotopically defined effective drainage basin area to lake volume (eDBA/LV, r2 = 0.63). Drainage basin slope was only weakly associated with water quality, likely because of low topographic relief ([Formula: see text]11%). Higher Chlorophyta and Peridineae biomasses in wetland-dominated systems than in upland-dominated ones may coincide with greater NH4+ availability.

scholarly journals Regional GRACE-based estimates of water mass variations over Australia: validation and interpretation

2013 ◽  
Vol 17 (12) ◽  
pp. 4925-4939 ◽  
Author(s):  
L. Seoane ◽  
G. Ramillien ◽  
F. Frappart ◽  
M. Leblanc
Keyword(s):  
Water Mass ◽  
Drainage Basin ◽  
Principal Component ◽  
Component Analysis ◽  
Climate Index ◽  
Accurate Estimation ◽  
Total Water ◽  
Spatial And Temporal Patterns ◽  
Regional Solutions

Abstract. Time series of regional 2° × 2° Gravity Recovery and Climate Experiment (GRACE) solutions have been computed from 2003 to 2011 with a 10-day resolution by using an energy integral method over Australia (112° E–156° E; 44° S–10° S). This approach uses the dynamical orbit analysis of GRACE Level 1 measurements, and specially accurate along-track K-band range rate (KBRR) residuals with a 1 μm s−1 level of errors, to estimate the total water mass over continental regions. The advantages of regional solutions are a significant reduction of GRACE aliasing errors (i.e. north–south stripes) providing a more accurate estimation of water mass balance for hydrological applications. In this paper, the validation of these regional solutions over Australia is presented, as well as their ability to describe water mass change as a response of climate forcings such as El Niño. Principal component analysis of GRACE-derived total water storage (TWS) maps shows spatial and temporal patterns that are consistent with independent data sets (e.g. rainfall, climate index and in situ observations). Regional TWS maps show higher spatial correlations with in situ water table measurements over Murray–Darling drainage basin (80–90%), and they offer a better localization of hydrological structures than classical GRACE global solutions (i.e. Level 2 Groupe de Recherche en Géodésie Spatiale (GRGS)) products and 400 km independent component analysis solutions as a linear combination of GRACE solutions provided by different centers.

scholarly journals Is the impact of eutrophication on phytoplankton diversity dependent on lake volume/ecosystem size?

2016 ◽  
Author(s):  
Didier L. Baho ◽  
Stina Drakare ◽  
Richard K. Johnson ◽  
Craig R. Allen ◽  
David G. Angeler
Keyword(s):  
Species Diversity ◽  
Growing Season ◽  
Phytoplankton Diversity ◽  
Habitat Features ◽  
Anthropogenic Stressors ◽  
Lake Volume ◽  
Ecosystem Size ◽  
Phytoplankton Communities ◽  
The Impact ◽  
Local Habitat

<p>Research focusing on biodiversity responses to the interactions of ecosystem size and anthropogenic stressors are based mainly on correlative gradient studies, and may therefore confound size-stress relationships due to spatial context and differences in local habitat features across ecosystems. We investigated how local factors related to anthropogenic stressors (<em>e.g.,</em> eutrophication) interact with ecosystem size to influence species diversity. In this study, constructed lake mesocosms (with two contrasting volumes: 1020 (shallow mesocosms) and 2150 (deep mesocosms) litres) were used to simulate ecosystems of different size and manipulated nutrient levels to simulate mesotrophic and hypertrophic conditions. Using a factorial design, we assessed how the interaction between ecosystem size and nutrients influences phytoplankton diversity. We assessed community metrics (richness, diversity, evenness and total biovolumes) and multivariate community structure over a growing season (May to early November 2011). Different community structures were found between deep and shallow mescosoms with nutrient enrichment: Cyanobacteria dominated in the deep and Charophyta in the shallow mesocosms. In contrast, phytoplankton communities were more similar to each other in the low nutrient treatments; only Chlorophyta had generally a higher biovolume in the shallow compared to the deep mesocosms. These results suggest that ecosystem size is not only a determinant of species diversity, but that it can mediate the influence of anthropogenic effects on biodiversity. Such interactions increase the uncertainty of global change outcomes, and should therefore not be ignored in risk/impact assessment and management.</p>

Forest harvest impacts on water quality and aquatic biota on the Boreal Plain: introduction to the TROLS lake program

2001 ◽  
Vol 58 (2) ◽  
pp. 421-436 ◽  
Author(s):  
E E Prepas ◽  
B Pinel-Alloul ◽  
D Planas ◽  
G Méthot ◽  
S Paquet ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Zooplankton Biomass ◽  
Phosphorus Concentration ◽  
Zooplankton Abundance ◽  
Total Phosphorus Concentration ◽  
Buffer Strip ◽  
Stratified Lakes ◽  
Lake Volume ◽  
Order Of Magnitude

Eleven headwater lakes in Alberta's Boreal Plain were monitored for nutrients and plankton 2 years before and 2 years after variable watershed harvesting (harvesting mean 15%, range 0-35%). After harvesting, variations in annual precipitation resulted in lake water residence times that differed by an order of magnitude from one year to the next. During the first posttreatment year, total phosphorus concentrations increased (overall 40%) in most lakes; however, response was most consistent in lakes that were shallow and the water column mixed or weakly thermally stratified. Chlorophyll a, cyanobacteria (Aphanizomenon-Anabaena), and cyanotoxins (microcystin-LR) increased after harvesting, primarily in shallow lakes. Zooplankton abundance and biomass decreased after harvesting, particularly in stratified lakes where edible phytoplankton biomass declined. In the weakly or nonstratified lakes, declines in zooplankton biomass were associated with higher cyanobacterial biomass and cyanotoxins. Posttreatment change in total phosphorus concentration was strongly related to weather (greatest response in a wet year) and relative drainage basin size (drainage basin area to lake volume, r2 = 0,78, P << 0,01). There was no evidence that buffer strip width (20, 100, and 200 m) influenced lake response. These results suggest that activities within the entire watershed should be the focus of catchment-lake interactions.

scholarly journals Estimation of the Particulate Organic Carbon to Chlorophyll-a Ratio Using MODIS-Aqua in the East/Japan Sea, South Korea

2020 ◽  
Vol 12 (5) ◽  
pp. 840 ◽  
Author(s):  
Dabin Lee ◽  
SeungHyun Son ◽  
HuiTae Joo ◽  
Kwanwoo Kim ◽  
Myung Joon Kim ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Chlorophyll A ◽  
Primary Productivity ◽  
Seasonal Variability ◽  
Japan Sea ◽  
Global Ocean ◽  
Phytoplankton Communities

In recent years, the change of marine environment due to climate change and declining primary productivity have been big concerns in the East/Japan Sea, Korea. However, the main causes for the recent changes are still not revealed clearly. The particulate organic carbon (POC) to chlorophyll-a (chl-a) ratio (POC:chl-a) could be a useful indicator for ecological and physiological conditions of phytoplankton communities and thus help us to understand the recent reduction of primary productivity in the East/Japan Sea. To derive the POC in the East/Japan Sea from a satellite dataset, the new regional POC algorithm was empirically derived with in-situ measured POC concentrations. A strong positive linear relationship (R2 = 0.6579) was observed between the estimated and in-situ measured POC concentrations. Our new POC algorithm proved a better performance in the East/Japan Sea compared to the previous one for the global ocean. Based on the new algorithm, long-term POC:chl-a ratios were obtained in the entire East/Japan Sea from 2003 to 2018. The POC:chl-a showed a strong seasonal variability in the East/Japan Sea. The spring and fall blooms of phytoplankton mainly driven by the growth of large diatoms seem to be a major factor for the seasonal variability in the POC:chl-a. Our new regional POC algorithm modified for the East/Japan Sea could potentially contribute to long-term monitoring for the climate-associated ecosystem changes in the East/Japan Sea. Although the new regional POC algorithm shows a good correspondence with in-situ observed POC concentrations, the algorithm should be further improved with continuous field surveys.

scholarly journals Empirical Relationships between Remote-Sensing Reflectance and Selected Inherent Optical Properties in Nordic Sea Surface Waters for the MODIS and OLCI Ocean Colour Sensors

2020 ◽  
Vol 12 (17) ◽  
pp. 2774
Author(s):  
Marta Konik ◽  
Piotr Kowalczuk ◽  
Monika Zabłocka ◽  
Anna Makarewicz ◽  
Justyna Meler ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Large Scale ◽  
Field Work ◽  
The Arctic ◽  
Significant Shift ◽  
Form Complex ◽  
Water Properties ◽  
Remote Sensing Reflectance ◽  
Phytoplankton Communities

The Nordic Seas and the Fram Strait regions are a melting pot of a number of water masses characterized by distinct optical water properties. The warm Atlantic Waters transported from the south and the Arctic Waters from the north, combined with the melt waters contributing to the Polar Waters, mediate the dynamic changes of the year-to-year large-scale circulation patterns in the area, which often form complex frontal zones. In the last decade, moreover, a significant shift in phytoplankton phenology in the area has been observed, with a certain northward expansion of temperate phytoplankton communities into the Arctic Ocean which could lead to a deterioration in the performance of remote sensing algorithms. In this research, we exploited the capability of the satellite sensors to monitor those inter-annual changes at basin scales. We propose locally adjusted algorithms for retrieving chlorophyll a concentrations Chla, absorption by particles ap at 443 and 670 nm, and total absorption atot at 443 and 670 nm developed on the basis of intensive field work conducted in 2013–2015. Measured in situ hyper spectral remote sensing reflectance has been used to reconstruct the MODIS and OLCI spectral channels for which the proposed algorithms have been adapted. We obtained MNB ≤ 0.5% for ap(670) and ≤3% for atot(670) and Chla. RMS was ≤30% for most of the retrieved optical water properties except ap(443) and Chla. The mean monthly mosaics of ap(443) computed on the basis of the proposed algorithm were used for reconstructing the spatial and temporal changes of the phytoplankton biomass in 2013–2015. The results corresponded very well with in situ measurements.

Heme b distributions through the Atlantic Ocean: in situ identification of iron limited phytoplankton

2020 ◽  
Author(s):  
Evangelia Louropoulou ◽  
Martha Gledhill ◽  
Eric P. Achterberg ◽  
Thomas J. Browning ◽  
David J. Honey ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Large Scale ◽  
North Atlantic Ocean ◽  
Iron Status ◽  
Mean Value ◽  
Particulate Material ◽  
South Atlantic ◽  
Phytoplankton Communities ◽  
The Impact

&lt;p&gt;Heme &lt;em&gt;b&lt;/em&gt; is an iron-containing cofactor in hemoproteins that participates in the fundamental processes of photosynthesis and respiration in phytoplankton. Heme &lt;em&gt;b&lt;/em&gt; concentrations typically decline in waters with low iron concentrations but due to lack of field data, the distribution of heme &lt;em&gt;b&lt;/em&gt; in particulate material in the ocean is poorly constrained. Within the framework of the Helmholtz Research School for Ocean System Science and Technology (HOSST) and the GEOTRACES programme, the authors compiled datasets and conducted multidisciplinary research (e.g. chemical oceanography, microbiology, biogeochemical modelling) in order to test heme &lt;em&gt;b&lt;/em&gt; as an indicator of &lt;em&gt;in situ&lt;/em&gt; iron-limited phytoplankton. This study was initiated in the North Atlantic Ocean and expanded to the under-sampled South Atlantic Ocean for comparison of the results considering the different phytoplankton populations. Here, we report particulate heme &lt;em&gt;b&lt;/em&gt; distributions across the Atlantic Ocean (59.9&amp;#176;N to 34.6&amp;#176;S). Heme &lt;em&gt;b&lt;/em&gt; concentrations in surface waters ranged from 0.10 to 33.7 pmol L&lt;sup&gt;-1&lt;/sup&gt; (median=1.47 pmol L&lt;sup&gt;-1&lt;/sup&gt;, n=974) and were highest in regions with a high biomass. The ratio of heme &lt;em&gt;b&lt;/em&gt; to particulate organic carbon (POC) exhibited a mean value of 0.44 &amp;#956;mol heme&lt;em&gt; b&lt;/em&gt; mol&lt;sup&gt;-1 &lt;/sup&gt;POC. We identified the ratio of 0.10 &amp;#181;mol heme &lt;em&gt;b&lt;/em&gt; mol&lt;sup&gt;-1&lt;/sup&gt; POC as the cut-off between heme &lt;em&gt;b&lt;/em&gt; replete and heme &lt;em&gt;b&lt;/em&gt; deficient phytoplankton. By this definition, the ratio heme &lt;em&gt;b&lt;/em&gt; relative to POC was consistently below 0.10 &amp;#956;mol mol&lt;sup&gt;-1&lt;/sup&gt; in areas characterized by low Fe supply; these were the Subtropical South Atlantic gyre and the seasonally iron limited Irminger Basin. Thus, the ratio heme &lt;em&gt;b&lt;/em&gt; relative to POC gave a reliable indication of iron limited phytoplankton communities in situ. Furthermore, the comparison of observed and modelled heme &lt;em&gt;b&lt;/em&gt; suggested that heme &lt;em&gt;b&lt;/em&gt; could account for between 0.17-9.1% of biogenic iron. This range was comparable to previous culturing observations for species with low heme &lt;em&gt;b&lt;/em&gt; content and species growing in low Fe (&amp;#8804;0.50 nmol L&lt;sup&gt;-1&lt;/sup&gt;) or nitrate culturing media. Our large scale observations of heme&lt;em&gt; b&lt;/em&gt; relative to organic matter suggest the impact of changes in iron supply on phytoplankton iron status.&lt;/p&gt;

Fluvial clastic sediment yield in Canada: scaled analysis

1999 ◽  
Vol 36 (8) ◽  
pp. 1267-1280 ◽  
Author(s):  
Michael Church ◽  
Darren Ham ◽  
Marwan Hassan ◽  
Olav Slaymaker
Keyword(s):  
Suspended Sediment ◽  
Sediment Yield ◽  
Sediment Load ◽  
Drainage Basin ◽  
Scaling Relations ◽  
Southern Ontario ◽  
Fluvial Sediment ◽  
Predicted Values ◽  
River Valleys ◽  
Basin Area

This report presents a set of maps of regional fluvial sediment yield in Canada, based mainly on the Water Survey of Canada archive of riverine suspended sediment observations. Regional scaling relations for the variation of suspended sediment load with drainage basin area are established to permit data to be adjusted to common areal bases for portrayal of regional variations. For most regions, the specific sediment yield increases downstream, indicating regional degradation of river valleys. In the southern prairies, however, regional aggradation is occurring, and in southern Ontario similar quantities of fluvial sediment are apparently being yielded, on average, over all scales in the landscape. A smoothed regional portrayal of the results is obtained by kriging, which also yields error estimates for locally predicted values of sediment yield. Maps are presented for the standard areas of 1 km2, 102 km2 (10 km × 10 km), and 104 km2 (102 km × 102 km).

scholarly journals A numerical evaluation of global oceanic emissions of α-pinene and isoprene

2010 ◽  
Vol 10 (4) ◽  
pp. 2007-2015 ◽  
Author(s):  
G. Luo ◽  
F. Yu
Keyword(s):  
Numerical Evaluation ◽  
Input Data ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Top Down ◽  
Mixing Processes ◽  
Bottom Up ◽  
Phytoplankton Communities ◽  
Oceanic Emissions

Abstract. A numerical evaluation of global oceanic emissions of α-pinene and isoprene based on both "bottom-up" and "top-down" methods is presented. We infer that the global "bottom-up" oceanic emissions of α-pinene and isoprene are 0.013 TgC yr−1 and 0.32 TgC yr−1, respectively. By constraining global chemistry model simulations with the shipborne measurement of Organics over the Ocean Modifying Particles in both Hemispheres summer cruise, we derived the global "top-down" oceanic α-pinene source of 29.5 TgC yr−1 and isoprene source of 11.6 TgC yr−1. Both the "bottom-up" and "top-down" values are subject to large uncertainties. The incomplete understanding of the in-situ phytoplankton communities and their range of emission potentials significantly impact the estimated global "bottom-up" oceanic emissions, while the estimated total amounts of the global "top-down" oceanic sources can be influenced by emission parameterizations, model and input data spatial resolutions, boundary layer mixing processes, and the treatments of chemical reactions. The global oceanic α-pinene source and its impact on organic aerosol formation is significant based on "top-down" method, but is negligible based on "bottom-up" approach. Our research highlights the importance of carrying out further research (especially measurements) to resolve the large offset in the derived oceanic organic emission based on two different approaches.

Changes in phytoplankton communities following logging in the drainage basins of three boreal forest lakes in northwestern Ontario (Canada), 1991–2000

2003 ◽  
Vol 60 (1) ◽  
pp. 43-54 ◽  
Author(s):  
K H Nicholls ◽  
R J Steedman ◽  
E C Carney
Keyword(s):  
Boreal Forest ◽  
Drainage Basin ◽  
Forest Harvesting ◽  
Intermediate Disturbance Hypothesis ◽  
Drainage Basins ◽  
Mixing Depth ◽  
Buffer Strip ◽  
Northwestern Ontario ◽  
Phytoplankton Communities ◽  
Forest Lakes

The phytoplankton communities of three small boreal forest lakes (L26, L39, and L42) on Ontario's Precambrian Shield (Canada) were investigated over 10 years for possible effects of forest harvesting (logging) within their drainage basins (5 years before logging vs. 5 years after logging). During the postlogging period, higher biovolumes of several taxa were recorded, consistent with previously reported changes in nutrients, chlorophyll, light penetration, and mixing depth. Among the most dramatic changes were increases of 100 and 266% in Cyanophyceae in L39 and L42, respectively, 167% in Dinophyceae in L26, 51 and 130% in Chlorophyceae in L26 and L42, respectively, 182% in Bacillariophyceae in L26, and 53 and 73% in total phytoplankton in L26 and L42, respectively. Other effects associated with logging in the watersheds of these lakes included an increase in the numbers of taxa (in accordance with the intermediate disturbance hypothesis) and a decrease in interannual variability in phytoplankton community structure (in accordance with the ecosystem diversity–stability hypothesis). The less extensive logging of the L26 drainage basin and the maintenance of an unlogged shoreline buffer strip did not preclude apparent effects on phytoplankton comparable with some of those found in the other two lakes, where drainage basin logging was more extensive.

Determination of the drainage basin characteristics using vector GIS

2006 ◽  
Vol 37 (2) ◽  
pp. 129-142 ◽  
Author(s):  
H. Apaydin ◽  
F. Ozturk ◽  
H. Merdun ◽  
N.M. Aziz
Keyword(s):  
Form Factor ◽  
Drainage Basin ◽  
Drainage Density ◽  
Contour Length ◽  
Stream Length ◽  
Manual Method ◽  
Morphologic Characteristics ◽  
Basin Area ◽  
Relief Ratio

Detailed geomorphologic characteristics need to be compiled for performing hydrologic modeling of a basin. Basin form and hydrologic characteristics are to be related so the basin form must also be represented by quantitative descriptors. The typical morphologic characteristics used in hydrological analyses are basin area, perimeter, mainstream length, total stream length, contour length, basin shape (form factor, circularity ratio, compactness ratio, basin elongation), slope, drainage density, relief (maximum relief, relief ratio, relative relief), effective basin width, and median elevation. The objective of this study is to propose an algorithm to automatically calculate basin characteristics using vector GIS. The results produced by the algorithm were compared to the manual method and the two methods were found statistically similar.

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