The relation between sediment nutrient content and macrophyte biomass and community structure along a water transparency gradient among lakes of the Mackenzie Delta

2003 ◽  
Vol 60 (3) ◽  
pp. 333-343 ◽  
Author(s):  
Margaret M Squires ◽  
Lance FW Lesack

Macrophyte abundance and distribution among lakes of the Mackenzie Delta were assessed where increasing distance from the river (chain set) and increasing frequency of flooding (sill set) corresponded with increasing water transparency. Overall, sediment organic matter (OM) and total nitrogen (TN) content increased with increasing biomass of macrophytes but was higher in the sill set than in the chain set. The amount of phosphorus (P) in sediments was similar among lakes, but pore-water P was appreciably higher in the chain set. Increasing sediment OM and water clarity corresponded with increasing biomass of macrophytes in the lakes. Community structure shifted from dominance by erect Potamogeton at low and intermediate transparency and moderate sediment OM content to low-growing Chara and Ceratophyllum at high transparency and high sediment OM. Similar transparency in the chain set supported greater biomass of macrophytes than in the sill set. A high rate of inorganic sedimentation (linked with frequent flooding) and organic sedimentation (linked with high transparency and plant biomass) may result in the most suitable substrate for the growth of macrophytes among lakes of the Mackenzie Delta. Submersed plant biomass was higher in the Mackenzie Delta lakes than in temperate lakes and comparable to that in the temperate and tropical floodplains, despite the high-latitude location.

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 553
Author(s):  
Inga-Mareike Bach ◽  
Lisa Essich ◽  
Torsten Müller

Despite phosphorus resources on Earth being limited, over fertilization in many agricultural situations causes significant resource consumption. Phosphorus-recycling within agricultural production can reduce global dilution into the environment and is thus essential to secure sustainable future supply. This study investigated the fertilization efficacy of phosphorus fertilizers recycled from biogas digestates in maize shoots grown under controlled greenhouse conditions, in two soils, in a pot experiment. Variables investigated were plant-available phosphorus in soil, plant biomass production, and concentration of phosphorus, calcium, and magnesium in shoots. Soils were treated with three different fertilizer fractions, separated from biogas digestates, at equivalent phosphorus concentrations, using different combinations and application techniques, isolated or in combination, and compared to triple superphosphate (TSP) as a reference. One of the fractions (P-Salt) had effects on biomass production and plant phosphorus concentration equivalent to TSP in agricultural surface soil. In the second soil (with less active soil life and nutrient content), equivalence to TSP was achieved with combinations of two recycled fractions (P-Salt and dried solids). The enhancement of the phosphorus fertilizing effect by the solids was synergistic, indicating that the solids had a soil conditioning effect. The results show that biogas digestates are a valuable source for phosphorus recycling of fractions that have equivalent or even superior fertilizing properties compared to TSP.


1986 ◽  
Vol 64 (12) ◽  
pp. 2993-2998 ◽  
Author(s):  
Steven F. Oberbauer ◽  
Nasser Sionit ◽  
Steven J. Hastings ◽  
Walter C. Oechel

Three Alaskan tundra species, Carex bigelowii Torr., Betula nana L., and Ledum palustre L., were grown in controlled-environment chambers at two nutrition levels with two concentrations of atmospheric CO2 to assess the interactive effects of these factors on growth, photosynthesis, and tissue nutrient content. Carbon dioxide concentrations were maintained at 350 and 675 μL L−1 under photosynthetic photon flux densities of 450 μmol m−2 s−1 and temperatures of 20:15 °C (light:dark). Nutrient treatments were obtained by watering daily with 1/60- or 1/8- strength Hoagland's solution. Leaf, root, and total biomass were strongly enhanced by nutrient enrichment regardless of the CO2 concentration. In contrast, enriched atmospheric CO2 did not significantly affect plant biomass and there was no interaction between nutrition and CO2 concentration during growth. Leaf photosynthesis was increased by better nutrition in two species but was unchanged by CO2 enrichment during growth in all three species. The effects of nutrient addition and CO2 enrichment on tissue nutrient concentrations were complex and differed among the three species. The data suggest that CO2 enrichment with or without nutrient limitation has little effect on the biomass production of these three tundra species.


2009 ◽  
Vol 7 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Cesar Enrique de Melo ◽  
Jane Dilvana Lima ◽  
Eliete Francisca da Silva

The Cerrado in the Central Brazil is currently one of the most threatened ecosystems in the world. As a result, the aquatic habitats in this biome also undergo great impacts. Alterations related to land-use change increase sediment loadings in rivers, streams and lakes, resulting in sedimentation and decrease in water transparency. Water transparency determines underwater visibility conditions, and as a consequence fish assemblages respond to spatial and temporal changes in this variable. This work aimed to examine the influence of transparency on the abundance and distribution of Cynodontidae species, a visually oriented predatory fish group. Fish sampling was conducted in 15 sites located between Mortes and Araguaia rivers in the Bananal floodplain, Mato Grosso State. Regression analysis between relative abundance of Cynodontidae (in number of individuals and biomass) and water transparency showed a positive and highly significant correlation, indicating that this group shows species-specific habitat affinities for clearer waters. These results suggest that the increase in water turbidity in this region can affect the patterns of abundance and distribution of the Cynodontidae species, as well as other visually oriented fishes.


2016 ◽  
Vol 29 (1) ◽  
pp. 94-100 ◽  
Author(s):  
ADERVAN FERNANDES SOUSA ◽  
LINDBERGUE ARAÚJO CRISOSTOMO ◽  
OLMAR BALLER WEBER ◽  
MARIA EUGENIA ORTIZ ESCOBAR ◽  
TEÓGENES SENNA DE OLIVEIRA

ABSTRACT: Irrigation using produced water, which is generated during crude oil and gas recovery and treated by the exploration industry, could be an option for irrigated agriculture in semiarid regions. To determine the viability of this option, the effects of this treated water on the nutritional status of plants should be assessed. For this purpose, we examined the nutritional changes in sunflowers after they were irrigated with oil-produced water and the effects of this water on plant biomass and seed production. The sunflower cultivar BRS 321 was grown for three crop cycles in areas irrigated with filtered produced water (FPW), reverse osmosis-treated produced water (OPW), or ground water (GW). At the end of each cycle, roots, shoots, and seeds were collected to examine their nutrient concentrations. Produced water irrigation affected nutrient accumulation in the sunflower plants. OPW irrigation promoted the accumulation of Ca, Na, N, P, and Mg. FPW irrigation favored the accumulation of Na in both roots and shoots, and biomass and seed production were negatively affected. The Na in the shoots of plants irrigated with FPW increased throughout the three crop cycles. Under controlled conditions, it is possible to reuse reverse osmosis-treated produced water in agriculture. However, more long-term research is needed to understand its cumulative effects on the chemical and biological properties of the soil and crop production.


2021 ◽  
Vol 869 (1) ◽  
pp. 012037
Author(s):  
F Sulawesty ◽  
G P Yoga ◽  
L Subehi ◽  
R Rosidah

Abstract The occurrence of land changes around Lake Menjer, Central Java Province will affect the condition of water quality subsequently will affect biota, including phytoplankton. The purposes of study was to analyze the composition and abundance of phytoplankton in Menjer Lake regarding to nutrient content i.e. nitrogen and phosphorus. Observations on the phytoplankton community were conducted in July and October 2019 at six locations in Menjer Lake. Water samples were taken at the water surface as much as 10 L filtered using plankton net. Identification was carried out under the inverted microscope Diaphot 300. The abundance was calculated using the Sedgwick Rafter cell counting (SRCC) method. Analysis of the phytoplankton community structure was derived by calculating the Diversity Index, Evenness Index, and Simpson Dominance Index. The nutrient content in Menjer Lake influences the structure of phytoplankton communities quantitatively and qualitatively. Observation showed that the diversity of phytoplankton was low and there was one species dominanted, the result explained that the phytoplankton community in Menjer Lake is unstable and there is ecological pressure on the community. It can be concluded that the improvement of environmental conditions around Menjer Lake is the basis for the sustainable management of Menjer Lake.


Author(s):  
Buya Azmedia Istiqlal ◽  
I Wayan Kasa ◽  
Deny Suhernawan Yusup

The diversity of intertidal invertebrates in Bali was believed to be affected by human activities, due to high rate of development in tourism industry. In order to reveal the real natural invertebrate diversity, it is necessary to investigate it at a kind of untouched beach of Bali. This study was perform by comparing invertebrate diversity (species richness, density, community structure) and human activity (Type, frequency) in Merta Segara Beach, as the beach with frequent human activities, and Nyangnyang Beach, as the beach with little human activities. Invertebrates sample were taken within intertidal zone using line transect-quadrate during low tide. Human activities were observed in the afternoon from March to April 2016. The result showed a significant different in density and community structure between both Merta Segara and Nyangnyang beach as the consequences of different substrate type of both beaches. Walking on substrate or trampling was believed to be the most influencing activity for invertebrate diversity, especially for Merta Segara Beach. Next, a thorough study must be performed to conclusively tie the human activity to the alteration of invertebrate diversity in a coastal area. The high diversity, density and abundance of intertidal invertebrate of Nyangnyang Beach has literally shown that how diverse the biodiversity could be if the beach were protected from overexploited by tourism visitation and activity.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan David Bogotá-Gregory ◽  
Flávio C. T. Lima ◽  
Sandra B. Correa ◽  
Cárlison Silva-Oliveira ◽  
David G. Jenkins ◽  
...  

Abstract Amazonian waters are classified into three biogeochemical categories by dissolved nutrient content, sediment type, transparency, and acidity—all important predictors of autochthonous and allochthonous primary production (PP): (1) nutrient-poor, low-sediment, high-transparency, humic-stained, acidic blackwaters; (2) nutrient-poor, low-sediment, high-transparency, neutral clearwaters; (3) nutrient-rich, low-transparency, alluvial sediment-laden, neutral whitewaters. The classification, first proposed by Alfred Russel Wallace in 1853, is well supported but its effects on fish are poorly understood. To investigate how Amazonian fish community composition and species richness are influenced by water type, we conducted quantitative year-round sampling of floodplain lake and river-margin habitats at a locality where all three water types co-occur. We sampled 22,398 fish from 310 species. Community composition was influenced more by water type than habitat. Whitewater communities were distinct from those of blackwaters and clearwaters, with community structure correlated strongly to conductivity and turbidity. Mean per-sampling event species richness and biomass were significantly higher in nutrient-rich whitewater floodplain lakes than in oligotrophic blackwater and clearwater river-floodplain systems and light-limited whitewater rivers. Our study provides novel insights into the influences of biogeochemical water type and ecosystem productivity on Earth’s most diverse aquatic vertebrate fauna and highlights the importance of including multiple water types in conservation planning.


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