Salmon Carcasses Increase Stream Productivity More than Inorganic Fertilizer Pellets: A Test on Multiple Trophic Levels in Streamside Experimental Channels

2010 ◽  
Vol 139 (3) ◽  
pp. 824-839 ◽  
Author(s):  
Mark S. Wipfli ◽  
John P. Hudson ◽  
John P. Caouette ◽  
Nicole L. Mitchell ◽  
Joanna L. Lessard ◽  
...  
Keyword(s):  
Trophic Levels ◽  
Inorganic Fertilizer ◽  
Stream Productivity ◽  
Salmon Carcasses

Elevated levels of δ15N in riverine Painted Turtles (Chrysemys picta): trophic enrichment or anthropogenic input?

2013 ◽  
Vol 91 (12) ◽  
pp. 899-905 ◽  
Author(s):  
Natalie R. Hofmeister ◽  
Megan Welk ◽  
Steven Freedberg
Keyword(s):  
Trophic Position ◽  
Abiotic Factors ◽  
Chrysemys Picta ◽  
Trophic Levels ◽  
Inorganic Fertilizer ◽  
Freshwater Turtle ◽  
Agricultural Activity ◽  
Painted Turtles ◽  
Animal Populations ◽  
Trophic Enrichment

The natural abundance of stable isotopes of elements in animal tissue is influenced by both biotic and abiotic factors. Biotically, animals feeding at higher trophic levels are enriched in the ratio of 15N:14N (δ15N) relative to their food resources owing to the preferential excretion of 14N. Abiotically, increases in δ15N may also reflect different sources of biologically available nitrogen, including nitrogen resulting from denitrification of inorganic fertilizer. We studied variation in δ15N among freshwater turtle populations to assess spatial variation in δ15N and to determine whether this variation can be attributed to differences in nitrogen source or trophic enrichment. We examined nitrogen and carbon stable isotope ratios in duckweed (genus Lemna L.) and in Painted Turtles (Chrysemys picta (Schneider, 1783)) in aquatic ecosystems expected to be differentially affected by agricultural activity and denitrification of inorganic fertilizer. Across sites, C. picta δ15N was strongly correlated with Lemna δ15N and was elevated in sites influenced by agricultural activity. Furthermore, trophic position of turtles was not associated with δ15N but was consistent with expected values for primary consumers in freshwater systems, indicating that differences in tissue δ15N could be attributed to differences in initial sources of nitrogen in each ecosystem. Our results suggest that care must be taken when attributing differences in isotopic values of animal populations to trophic factors.

Increased Stream Productivity with Warming Supports Higher Trophic Levels

2013 ◽  
pp. 285-342 ◽  
Author(s):  
Elísabet Ragna Hannesdóttir ◽  
Gísli Már Gíslason ◽  
Jón S. Ólafsson ◽  
Ólafur Patrick Ólafsson ◽  
Eoin J. O’Gorman
Keyword(s):  
Trophic Levels ◽  
Stream Productivity

Relationship between morphometrics and trophic levels in deep-sea fishes

2020 ◽  
Vol 637 ◽  
pp. 225-235 ◽  
Author(s):  
MA Ladds ◽  
MH Pinkerton ◽  
E Jones ◽  
LM Durante ◽  
MR Dunn
Keyword(s):  
Stable Isotopes ◽  
Trophic Level ◽  
Deep Sea ◽  
Strong Relationship ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Fish Size ◽  
Wide Range ◽  
Gape Size ◽  
Morphological Variables

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.

Lowland Rice Yield as Affected by Straw Incorporation and Inorganic Fertilizer Over Cropping Seasons in Fluvisol

2014 ◽  
Vol 3 (1) ◽  
pp. 129-141
Author(s):  
Brahima Koné ◽  
Zadi Florent ◽  
Gala bi Trazié Jeremie ◽  
Akassimadou Edja Fulgence ◽  
Konan Kouamé Firmin ◽  
...  
Keyword(s):  
Grain Yield ◽  
Rice Variety ◽  
Mineral Fertilizer ◽  
Lowland Rice ◽  
Inorganic Fertilizer ◽  
Cropping Season ◽  
Significant Difference ◽  
Straw Incorporation ◽  
Cropping Seasons ◽  
Fertilizer Effect

Grain yield stabilization of lowland rice over cropping seasons was explored using different compositions of inorganic fertilizers (NPK, NPKCa, NPKMg, NPKZn, NPKCaMg, NPKCaZn and NPKCaMgZn) and straw incorporation (3, 6, 9, 12 and 15 tha-1 ). No fertilizer and no straw amended plot was the control in a split-plot design with three replications laid in a Fluvisol of Guinea savanna in Centre Cote d’Ivoire. Three weeks old nursery rice variety NERICA L19 was transplanted. No significant difference of grain yield was observed between the different treatments excluding the highest yields recorded for treatments NPKMg (5.09 tha-1 ), NPKZn (5.15 tha-1 ) and NPKCaéMg (5.31 tha-1 ) compared with 12 (3.95 tha1 ) and 15 tha-1 (4.14 tha-1 ) as straw rates respectively. Grain yield declining trend was more pronounced for mineral fertilizer treatments showing twice greater depressive effect of cropping cycle compared with the straw especially, for treatments characterized by highest grain yield in the first cropping season and similar grain yields were recorded for both sources of nutrient in the third cropping cycle. Of slowness of nutrients releasing by straw, highest grain yield was expected for this soil amender within a longer period of cultivation whereas, unbalance soil micronutrients should be relevant to studious declining yield under inorganic fertilizer effect. Nevertheless, the straw rate of 12 tha-1 supplying 0.58% of NPK as mineral fertilizer equivalent can be recommended for sustaining lowland rice production in the studied agro-ecosystems unless for three cropping seasons.

PEMANFAATAN LIMBAH JAGUNG MENJADI PUPUK ORGANIK UNTUK PENYUBURAN LAHAN PERTANIAN

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Daru Mulyono
Keyword(s):  
Agricultural Land ◽  
Organic Fertilizer ◽  
Economic Value ◽  
Soil Microorganism ◽  
Appropriate Technology ◽  
Inorganic Fertilizer ◽  
Plant Materials ◽  
Chemical Soil ◽  
Stem Leaf

The use of maize waste plant materials (stem, leaf, and husk cover) have high economic value to be processed become organic fertilizer for agricultural land fertilizer. Maize have several and quite high contents of macro and micro nutrients. This activity was hoped that the farmers can overcome the increasing price of inorganic fertilizer recently and furthermore farmers can reap higher income. Beside higher income the use of organic fertilizer can improve the nature and behaviourof land through improving of soil chemical, soil physical, and soil microorganism. Therefore, the appropriate technology for processing of maize become organic fertilizer is very important to be diffused or socialized to farmers.Keywords: fertilizer, maize waste

ENERGY TRANSFER EFFICIENCIES ON LOWER TROPHIC LEVELS WITH INTENSIVE OYSTER FARMING IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Akira Umehara ◽  
Akira Umehara ◽  
Satoshi Asaoka ◽  
Satoshi Asaoka ◽  
Naoki Fujii ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Primary Production ◽  
Skeletonema Costatum ◽  
Warm Season ◽  
Nutrient Supply ◽  
Trophic Levels ◽  
Phytoplankton Primary Production ◽  
Mean Values ◽  
Hiroshima Prefecture ◽  
Study Species

In enclosed water areas, organic matters are actively produced by phytoplankton due to abundant nutrient supply from the rivers. In our study area of the semi-enclosed Hiroshima Bay, oyster farming consuming high primary production has been developed since the 1950s, and the oyster production of Hiroshima prefecture have had the largest market share (ca. 60%) in Japan. In this study, species composition of phytoplankton, primary production, and secondary production of net zooplanktons and oysters were determined seasonally at seven stations in the bay between November 2014 and August 2015. In the bay, diatoms including Skeletonema costatum dominated during the period of the study. The primary productions markedly increased during summer (August), and its mean values in the northern part of the bay (NB) and the southern part (SB) were 530 and 313 mgC/m2/d, respectively. The productions of net zooplankton and oyster increased during the warm season, and its mean values in the NB were 14 and 1.2 mgC/m2/d, and in SB were 28 and 0.9 mgC/m2/d, respectively. The energy transfer efficiencies from the primary producers to the secondary producers in the NB and SB were 2.8% and 9.1%, respectively. However, the transfer efficiency to the oysters was approximately 0.3% in the bay. This study clearly showed the spatial difference of the productions and transfer efficiencies, and the low contribution of the production of oysters in secondary productions in Hiroshima Bay.

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