Comparison of the biogeochemistry of lakes and estuaries: ecosystem processes, functional groups, hysteresis effects and interactions between macro- and microbiology

1999 ◽  
Author(s):  
Graham P. Harris
Keyword(s):  
Functional Groups ◽  
Aquatic Ecosystems ◽  
Ecosystem Processes ◽  
Phosphorus Limitation ◽  
Nitrogen And Phosphorus ◽  
Marine Systems ◽  
Minor Elements ◽  
Water Flows ◽  
Global Patterns ◽  
Nitrogen Phosphorus

This paper reviews the biogeochemistry of carbon, nitrogen, phosphorus and their associated minor elements (iron and sulfur) in rivers, lakes and estuaries. The biogeochemistry of these elements can be explained by the physiology and stoichiometry of the major functional groups of micro- and macro-biota in these ecosystems. Furthermore, the global patterns of nitrogen and phosphorus limitation in freshwater and marine systems are explicable in terms of evolutionary differences between the major functional groups in freshwater and marine ecosystems, and their physiology and stoichiometry, as well as the interactions of carbon, iron, water residence times and ionic strength as the water flows from catchments to the sea. The highly non-linear responses of aquatic ecosystems to changing catchment loads of major and minor elements are explained by the interactions of the major functional groups and by competition between the pelagic and the benthos for nutrients and light.

scholarly journals Influence of fertilizers, minor elements, and soil ph on the growth and protein content of tropical kudzu

1969 ◽  
Vol 37 (1) ◽  
pp. 81-95
Author(s):  
Pablo Landrau, Jr. ◽  
George Samuels ◽  
P. Rodríguez
Keyword(s):  
Protein Content ◽  
Protein Production ◽  
Acid Soils ◽  
Minor Element ◽  
Low Fertility ◽  
Lime Treatment ◽  
Nitrogen And Phosphorus ◽  
Minor Elements ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

The effect of fertilizers and lime on the yield and protein production of tropical kudzu, as observed in the experiments here reported, is as follows: 1. In a greenhouse experiment, kudzu yields increased with increased pH on limed soils, with the highest yield at pH 7.5. 2. Nitrogen and phosphorus produced significant increases in the yield of green forage in a fertilizer experiment on a Río Piedras clay. No such increases were obtained with potash fertilizers. 3. Liming increased yields for the first cutting of kudzu only in a fertilizer- lime experiment on a heavy plastic Fajardo clay. Nitrogen was also of significant value in increasing forage yields and protein for the first cutting only. The second and third cuttings had no yield or protein increases that could be attributed to any fertilizer or lime treatment. 4. At Corozal, on a friable, acid Lares clay, kudzu did not respond to nitrogen, phosphorus, and potassium fertilizers. The response to liming was in protein content and then only in the second and third cuttings. 5. The use of nitrogen and lime is of value in establishing good productive stands of kudzu on very acid soils (pH below 5) of low fertility. 6. The effects of the use of borax and of magnesium oxide as minor-element fertilizers were negligible from the standpoint of yield and protein production.

scholarly journals Global patterns of terrestrial nitrogen and phosphorus limitation

2020 ◽  
Vol 13 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Enzai Du ◽  
César Terrer ◽  
Adam F. A. Pellegrini ◽  
Anders Ahlström ◽  
Caspar J. van Lissa ◽  
...  
Keyword(s):  
Phosphorus Limitation ◽  
Nitrogen And Phosphorus ◽  
Global Patterns

scholarly journals The SN2 reaction and its relationship with the Walden inversion, the Finkelstein and Menshutkin reactions together with theoretical calculations for the Finkelstein reaction

2021 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero
Keyword(s):  
Linear Models ◽  
Theoretical Calculations ◽  
Computational Method ◽  
Basis Set ◽  
Free Energies ◽  
Nitrogen And Phosphorus ◽  
Atom Pairs ◽  
Leaving Groups ◽  
First Time ◽  
Nitrogen Phosphorus

AbstractThis communication gives an overview of the relationships between four reactions that although related were not always perceived as such: SN2, Walden, Finkelstein, and Menshutkin. Binary interactions (SN2 & Walden, SN2 & Menshutkin, SN2 & Finkelstein, Walden & Menshutkin, Walden & Finkelstein, Menshutkin & Finkelstein) were reported. Carbon, silicon, nitrogen, and phosphorus as central atoms and fluorides, chlorides, bromides, and iodides as lateral atoms were considered. Theoretical calculations provide Gibbs free energies that were analyzed with linear models to obtain the halide contributions. The M06-2x DFT computational method and the 6-311++G(d,p) basis set have been used for all atoms except for iodine where the effective core potential def2-TZVP basis set was used. Concerning the central atom pairs, carbon/silicon vs. nitrogen/phosphorus, we reported here for the first time that the effect of valence expansion was known for Si but not for P. Concerning the lateral halogen atoms, some empirical models including the interaction between F and I as entering and leaving groups explain the Gibbs free energies.

First comparison of quantitative estimates of termite biomass and abundance reveals strong intercontinental differences

2014 ◽  
Vol 30 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Cecilia A.L. Dahlsjö ◽  
Catherine L. Parr ◽  
Yadvinder Malhi ◽  
Homathevi Rahman ◽  
Patrick Meir ◽  
...  
Keyword(s):  
Functional Groups ◽  
Functional Diversity ◽  
Ecosystem Processes ◽  
Global Scale ◽  
Species Density ◽  
Abundance Data ◽  
Standardized Protocol ◽  
Biogeographical Distribution ◽  
Belt Transect

Abstract:Termite species and functional groups differ among regions globally (the functional-diversity anomaly). Here we investigate whether similar differences in biomass and abundance of termites occur among continents. Biomass and abundance data were collected with standardized sampling in Cameroon, Malaysia and Peru. Data from Peru were original to this study, while data from Cameroon and Malaysia were compiled from other sources. Species density data were sampled using a standardized belt transect (100 × 2 m) while the biomass and abundance measurements were sampled using a standardized protocol based on 2 × 2-m quadrats. Biomass and abundance data confirmed patterns found for species density and thus the existence of the functional diversity anomaly: highest estimates for biomass and abundance were found in Cameroon (14.5 ± 7.90 g m−2 and 1234 ± 437 ind m−2) followed by Malaysia (0.719 ± 0.193 g m−2 and 327 ± 72 ind m−2) and then Peru (0.345 ± 0.103 g m−2 and 130 ± 39 ind m−2). The biomass and abundance for each functional group were significantly different across sites for most termite functional groups. Biogeographical distribution of lineages was the primary cause for the functional diversity anomaly with true soil-feeding termites dominating in Cameroon and the absence of fungus-growing termites from Peru. These findings are important as the biomass and abundance of functional groups may be linked to ecosystem processes. Although this study allowed for comparisons between data from different regions further comparable data are needed to enhance the understanding of the role of termites in ecosystem processes on a global scale.

Water-Fertilizer Coupling Effects and Efficient Utilization under Peanut-Millet Interplanting Conditions

2013 ◽  
Vol 742 ◽  
pp. 272-277
Author(s):  
Liang Shan Feng ◽  
Zhan Xiang Sun ◽  
Jia Ming Zheng
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Coupling Effect ◽  
Field Capacity ◽  
Nitrogen And Phosphorus ◽  
Application Rates ◽  
Optimal Value ◽  
Factor Interactions ◽  
Nitrogen Phosphorus

In this study, the results showed that water is the most important factor to affect crop yields and optimum soil moisture is lower under the conditions of peanut-and-millet interplanting. Thus, peanut-and-millet interplanting is generally able to fit most of the semi-arid region. In the interaction of various factors, the coupling effect of water and phosphorus was stronger than the coupling effect of fertilizers, following by the coupling effect of water and nitrogen. Among peanuts factors of water, nitrogen, and multi-factorial interaction of water, nitrogen, and phosphorus, water and nitrogen showed a negative effect, whereas the two-factor interactions had a positive effect. There were some differences between peanut and millet in the need for water and fertilizer, in which peanut required more nitrogen and millet needed slightly higher soil moisture and phosphorus. When other factors were in rich level, both of the optimal value for single factors of water, nitrogen, and phosphorus and the optimal value for two-factor interactions of water-nitrogen, water-phosphorus, and nitrogen-phosphorus, were higher than the optimal value for the interaction of water, nitrogen, and phosphorus. The tiny demand difference on moisture in peanut-millet interplanting could be compromised by configuring a reasonable interplanting population structure and the corresponding demand difference on fertilizer could be resolved by uneven crop planting strips. Under the condition of water-nitrogen-phosphorus interaction, the soil moisture content optimal for peanut accounted for 57.3% of the field capacity, and the related appropriate application rates of nitrogen and phosphorus were 0.98 g/pot (81.18 kg/hm2) and 0.39g/pot (32.18 kg/hm2), respectively. Likewise, the soil moisture content optimal for millet was 59.1% of the field capacity, and the counterpart appropriate application rates of nitrogen and phosphorus were 0.57 g/pot (47.03 kg/hm2) and 0.45g / pot (37.13 kg/hm2), respectively.

Distribution of Biomass, Nitrogen, Phosphorus and Other Nutrients in Banksia marginata and B. ornata Shoots of Different Ages After Fire.

1986 ◽  
Vol 34 (6) ◽  
pp. 709 ◽  
Author(s):  
RH Groves ◽  
PJ Hocking ◽  
A Mcmahon
Keyword(s):  
National Park ◽  
Dry Matter ◽  
Lateral Roots ◽  
South Australia ◽  
Distribution Patterns ◽  
Nutrient Accumulation ◽  
Nitrogen And Phosphorus ◽  
Vegetative Organs ◽  
Western Victoria ◽  
Nitrogen Phosphorus

The heathland form of Banksia marginata Cav. regenerates rarely from seed but commonly by resprout- ing from buds on lateral roots, whereas Banksia ornata F. Muell. regenerates only from seed, usually released after fire. The two species co-occur in heath vegetation on nutrient-poor soils in south-eastern South Australia and western Victoria. Shoots were sampled from stands of B. marginata aged from 1 to 25 years and of B. ornata aged from 1 to 50+ years after fire in the Little Desert National Park, western Victoria. B. marginata, the resprouter, distributed a greater proportion of the total shoot dry matter and content of all nutrients to vegetative growth over its shorter life span than B. ornata, the non-sprouter. About 50% of the total phosphorus in B. ornata shoots at 50+ years was present in cones (including seeds) compared with only about 20% in B. marginata shoots at a comparable stage of senescence (25 years). This difference between the species was also true to a lesser degree for nitrogen. There were considerable differences between other nutrients in their distribution patterns in shoots. Nutrients could be grouped together on the basis of distribution in shoots more satisfactorily than on presumed physio- logical roles. Stems were major sites of nutrient accumulation in both species. The content of a particular nutrient in seeds as a proportion of the content in the living parts of the shoot ranged from 0.03% (Na, Mn) to 2.0% (P) in B. marginata, and from 0.3% (Na) to as high as 31% (P) in B. ornata. Concen- trations of all nutrients except sodium were much higher in seeds than in the woody cones or vegetative organs of both species; seeds of B. ornata were particularly rich in calcium and manganese. We conclude that the different patterns of distribution of biomass and nutrients, especially nitrogen and phosphorus, within shoots of the two species reflect their different regenerative modes after fire. Introduction Phosphorus and, to a lesser extent, nitrogen limit the growth of sclerophyllous shrubs on nutrient-poor soils in southern Australia

Sign in / Sign up

Export Citation Format

Share Document