Predictors of Relative Fish Biomass in Lakes and Reservoirs of Argentina

1990 ◽  
Vol 47 (5) ◽  
pp. 928-939 ◽  
Author(s):  
Rolando Quiros
Keyword(s):  
Data Base ◽  
Climatic Factors ◽  
Organic Matter Content ◽  
Zooplankton Biomass ◽  
Matter Content ◽  
Environmental Data ◽  
Fish Biomass ◽  
Total Organic Nitrogen ◽  
Screening Process ◽  
Lakes And Reservoirs

Relationships between total fish biomass and chlorophyll, nutrient levels, and morphometric and climatic factors are shown for a set of 106 Argentinian lakes and reservoirs. The total data base is highly heterogeneous. Relative fish biomass (CPUE) was estimated from gill net catches. A data screening process was applied to the environmental data base to homogenize it. Nutrient, total organic matter content, and mean depth were most important in explaining relative fish biomass variability between lakes and reservoirs. In most heterogeneous sets total organic nitrogen (TON) explained most of CPUE variability. After screening for limnological anomalies (i.e. turbidity derived from inorganic sources, unsuitable conditions for fish, and TN/TP (total nitrogen/total phosphorus) < 37 (molar basis)), TP and TON were highly correlated with CPUE. Mean annual air temperature was significantly related to fish biomass, but the relationship was not significant after nutrients, morphometry, and environmental oxygen conditions had been accounted for. Several possible causes are discussed. The results support the hypothesis that fish/phytoplankton, and fish/zooplankton biomass ratios are inversely related to lake trophy.

An analysis of vegetation–environment relationships in Saskatchewan sloughs

1968 ◽  
Vol 46 (4) ◽  
pp. 509-522 ◽  
Author(s):  
B. H. Walker ◽  
R. T. Coupland
Keyword(s):  
Frequency Distribution ◽  
Water Regime ◽  
Organic Matter Content ◽  
Total Dissolved Solids ◽  
Matter Content ◽  
Environmental Data ◽  
Dissolved Solids ◽  
Initial Water ◽  
Association Table ◽  
Associated Species

This study examined the relationships between the distribution of herbaceous species and some of the major environmental factors in sloughs. Frequency distribution of species was studied in 64 stands. Environmental data, collected in 40 of these, included weekly readings of water level, fortnightly readings of pH and total dissolved solids in water, and texture and organic matter content of topsoil and subsoil. An association table of 24 leading dominants, arranged so that strongly associated species were close together, corresponded closely to their observed order along a moisture gradient. Environmental scalars were constructed to combine data on pH and total dissolved solids, as well as initial water depth and rate of water loss. The soil data showed very little association with species distribution. Synthetic scalars for water regime and for water chemistry were plotted against one another to obtain an arrangement of stands. Plotting the frequency distribution of the leading dominant species over the environmental arrangement of stands showed most of the species to be strongly affected by the water regime and somewhat less affected by salinity. A few were restricted to a very narrow range of one of these factors, while others flourished in all segments of the environment. The relationships suggested by this analysis are largely in agreement with those suggested by the vegetation analysis alone.

scholarly journals Influence of Local Habitat and Climatic Factors on the Distribution of Fish Species in the Tonle Sap Lake

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 786 ◽  
Author(s):  
Bunyeth Chan ◽  
Sébastien Brosse ◽  
Zeb Hogan ◽  
Peng Ngor ◽  
Sovan Lek
Keyword(s):  
Spatial Distribution ◽  
Fish Species ◽  
Climatic Factors ◽  
Environmental Data ◽  
Fish Diversity ◽  
Fish Biomass ◽  
Tonle Sap Lake ◽  
Tonle Sap ◽  
Bioclimatic Variables ◽  
High Fish

Tonle Sap Lake (TSL) is a highly productive system and hosts a high fish diversity and is of paramount importance for sustaining protein supply for over 15 million Cambodians. Nevertheless, the ecology and factors influencing the spatial distribution of many fishes within the lake remain poorly understood. Using commercial fishing lot catch data from 1994/1995 to 1999/2000, fishing seasons and environmental data (land cover and bioclimatic variables), we describe spatial distribution of the eight most commercially important fish species, and investigate the effects of environmental factors on their distributions in the TSL. We found a strong variability in fish biomass across areas and between species. Specifically, Channa micropeltes was most abundant in the southern and northern sections of the TSL. Channa striata and Trichopodus microlepis were more common in the northern part of the TSL. Cyclocheilos enoplos, Barbonymus gonionotus, Pangasianodon hypophthalmus, and Gymnostomus spp. were abundant in the southern areas of the TSL while Phalacronotus spp. were abundant in few areas in both the north and the south. Flooded forest positively explained the variation in the biomass of P. hypophthalmus, C. striata, C. enopolos, and Phalacronotus spp. Likewise, the lake’s open water positively affects the biomass of P. hypophthalmus, C. enopolos, and Phalacronotus spp., while the agricultural field negatively impacts Gymnostomus spp. biomass distribution. We also found that some areas consistently hosted high fish biomass (e.g., lot 2, Kampong Thom; lot 6, Pursat; lot 2, Battambang, etc.). We, therefore, suggest that fisheries management and conservation planning focus on those areas, considering those areas significance as core fish habitat and important for catching fish.

scholarly journals Influence of climatic factors on the energy potential of broadleaf phytocoenosis forest bedding

2021 ◽  
Vol 4 ◽  
pp. 32-36
Author(s):  
Iryna Vyshenska ◽  
Alina Ginzhaliuk
Keyword(s):  
Organic Matter ◽  
Forest Ecosystem ◽  
Deciduous Forest ◽  
Climatic Factors ◽  
Meteorological Data ◽  
Organic Matter Content ◽  
Matter Content ◽  
Monthly Precipitation ◽  
Energy Potential ◽  
The Relationship

The study of the energy potential of forest bedding in the deciduous forest areas of the “Lisnyky” Nature Reserve of the Holosiivsky National Nature Park revealed the nonlinear nature of its annual dynamics. The main sources of replenishment of the organic stock of this component of broadleaf forest phytocoenosis were the active development of herbaceous vegetation in spring and significant leaf rainfall in autumn. At the same time, significant changes in the processes of accumulation and decomposition of organic matter of forest bedding occurred under the influence of climatic factors such as temperature and precipitation. The experimental site was located in moderately moist oak forest ass. Convallario majali-Quercetum roboris Shevchyk & V. Sl. in Shevchyk & al. 96. The age of the old Quercus robur oak trees, which occupy the first tier of the forest, exceeds 100 years. The second tier is formed by other broadleaf species, Acer platanoides, A. campestre, A. tataricum, Carpinus betulus, Fraxinus excelsior and Tilia cordata, up to 30 years old. The energy reserve was calculated from the dry organic matter content. The obtained data were compared with  meteorological data of the corresponding month of the year and correlation coefficients were calculated. Correlation analysis confirmed the relationship between climatic factors and the energy potential of forest bedding. The inverse of the mean force (R = -0.515) shows the relationship between the energy potential of the forest bedding and the average monthly temperature and the high direct correlation between the energy potential and the amount of average monthly precipitation (R = 0.755). In general, forest bedding can be considered an important component of the ecosystem, which responds quickly to external factors and characterizes the state of the forest ecosystem, and its energy potential can be an effective indicator of forest ecosystem stability in climate change monitoring.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.

UPAYA MEMPERTAHANKAN BUNGA DAN FRUIT SET TANAMAN CABAI (Capsicum annum L.) PADA LAHAN ULTISOL MELALUI PEMBERIAN LUMPUR LAUT DAN PUPUK KANDANG

2017 ◽  
Vol 13 (2) ◽  
pp. 74-77
Author(s):  
Imelda J Lawalatta ◽  
Francina Matulessy ◽  
Meitty L Hehanussa
Keyword(s):  
Fruit Set ◽  
Agricultural Land ◽  
Mineral Soil ◽  
Organic Matter Content ◽  
Nutrient Deficiency ◽  
Matter Content ◽  
Infrastructure Development ◽  
Capsicum Annum ◽  
Factor Effect ◽  
Marine Mud

Chili (Capsicum annum L.) often experience the highest price fluctuations in Indonesia. This is caused by the production that is often disrupted in certain months, especially in the months in the rainy season due to flowers and fruits that fall before the harvest. Since agricultural land has changed its function for infrastructure development, marginal land (Ultisol) is used. The ultisol problem is: high acidity, low organic matter content, nutrient deficiency important for plants (eg N, P, Ca, Mg and Mo) and high solubility of Al, Fe and Mn. The provision of organic materials such as manure and marine mud will overcome the problem of acid-rich mineral soil and play an important role in improving, increased and maintaining sustainable land productivity. Research results for chili flower significantly. the highest number of flowers found in the treatment of L0P3, L1P2, L1P3 and L2P3 that is > 60 flower/plant. There was a single factor effect for the amount of fruit, mostly found in L3 treatment (600 ton/ha marine mud) that is 22.36 fruit/plant. The treatment of manure significantly influenced the formation of the most fruit set in the treatment of P0 and P2 (without manure and manure 20 ton/ha) that is 77.60% and 70.,45%. Keywords: Ultisol, Marine mud, Manure, Flowers and Fruit sets   ABSTRAK Tanaman cabai besar (Capsicum annum L.) sering mengalami fluktuasi harga paling tinggi di Indonesia. Hal tersebut disebabkan oleh produksi yang sering terganggu pada bulan tertentu terutama pada bulan-bulan di musim penghujan dikarenakan bunga dan buah yang rontok sebelum panen. Karena lahan pertanian banyak beralih fungsinya untuk pembangunan infrastuktur, maka digunakan lahan marginal (Ultisol). Masalah ultisol ialah: kemasaman tinggi, kadar bahan organik yang rendah, kekurangan unsur hara penting bagi tanaman (contoh: N, P, Ca, Mg dan Mo) serta tingginya kelarutan Al, Fe dan Mn. Pemberian bahan organik seperti pupuk kandang dan Lumpur laut akan mengatasi persoalan tanah mineral masam berkadar Al tinggi dan berperan penting dalam memperbaiki, meningkatkan serta mempertahankan produktifitas lahan secara berkelanjutan Hasil Penelitian untuk jumlah bunga cabai berpengaruh signifikan. jumlah bunga terbanyak terdapat pada perlakuan L0P3, L1P2, L1P3 dan L2P3 yaitu > 60 bunga/tanaman. Terjadi pengaruh faktor tunggal untuk jumlah buah, terbanyak terdapat pada perlakuan L3 ( 600 ton/ha lumpur laut) yaitu 22,36 buah/tanaman. Perlakuan pupuk kandang berpengaruh signifikan Pembentukan fruit set terbanyak pada perlakuan P0 dan P2 (tanpa pupuk kandang dan pupuk kandang 20 ton/ha) yaitu 77,60% dan 70,45%. Kata kunci: Ultisol, Lumpur Laut, Pupuk Kandang, Bunga dan Fruit set

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply
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