The relationship between metal concentration and organic matter in sediments and metal concentration in the aquatic macrophyte Eriocaulon septangulare

Aquatic macrophyte productivity and soil organic matter were measured in two impermanent wetlands in south-western New South Wales. Macrophyte biomasses (≤463 g dry wt m-2) were similar to or higher than those in submerged communities elsewhere. Macrophyte productivities in both wetlands were greatest in the year following reflooding. But even in that year, macrophyte productivity in Lake Merrimajeel (the only wetland for which data are available) was considerably less than soil organic reserves before reflooding. It is suggested that these soil organic reserves directly contribute to the relationship between wetland flooding and waterfowl breeding, while macrophytes contribute indirectly by providing detritus for invertebrates. It is recommended that wetlands managed for waterfowl breeding should periodically dry out and reflood.

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Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure

Biomolecules ◽

10.3390/biom11030448 ◽

2021 ◽

Vol 11 (3) ◽

pp. 448

Author(s):

Mahrous Awad ◽

Zhongzhen Liu ◽

Milan Skalicky ◽

Eldessoky S. Dessoky ◽

Marian Brestic ◽

...

Keyword(s):

Heavy Metals ◽

Organic Matter ◽

Soil Organic Matter ◽

Soil Ph ◽

Contaminated Soil ◽

Contaminated Soils ◽

Extraction Procedure ◽

Sequential Fractionation ◽

Relationship Of ◽

The Relationship

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

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The use of faecal nitrogen as an index for estimating the consumption of herbage by grazing animals

The Journal of Agricultural Science ◽

10.1017/s0021859600013666 ◽

1963 ◽

Vol 61 (1) ◽

pp. 33-43 ◽

Cited By ~ 11

Author(s):

G. W. Arnold ◽

M. L. Dudzinski

Keyword(s):

Organic Matter ◽

Nitrogen Concentration ◽

Linear Equations ◽

Slope Position ◽

Seasonal Differences ◽

Faecal Nitrogen ◽

Independent Variable ◽

Regression Relations ◽

The Relationship ◽

Better Than

Data from thirty-five digestibility trials with sheep in metabolism cages were used to investigate statistically the relationships between organic matter intake (I), faecal organic matter output (F), and the nitrogen concentration in faecal organic matter (N).The data fell easily into groups due to botanical or seasonal differences in the feed. These groups of data were homogeneous and provided highly significant linear equations of the forms I = bF + cFN and I = a + cFN. When compared these groups of data sometimes showed differences in slope, position or both. A quadratic expressionI = bF + cFN + dFN2was found to accommodate a majority of the data but to be less precise than I = a + cFN.A further expression incorporating N as an independent variable was also examined,I = a + cFN2 + eN.This expression, although far from being universally adequate, proved to be generally better than existing formulae. When applied to the data of Greenhalgh et. al. (1960), it substantially reduced heterogeneity between data for spring and data for summer pastures.Causes of variation in the relationship between organic-matter intake and nitrogen in faeces, and some of the hazards of extrapolation from empirical regression relations, are discussed.

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The relationship between sediment metal concentration and Odonata (Insecta) larvae assemblage structure in Cerrado streams

Limnetica ◽

10.23818/limn.41.03 ◽

2022 ◽

Vol 41 (1) ◽

pp. 27-41

Author(s):

Cyntia Goulart Corrêa Bruno ◽

Regina Célia Gonçalves ◽

Ademir dos Santos ◽

Kátia Gomes Facure ◽

Juliano José Corbi ◽

...

Keyword(s):

Metal Concentration ◽

Assemblage Structure ◽

The Relationship ◽

Sediment Metal

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In vitro estimation of rumen fermentable organic matter using enzymes

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v44i2.550 ◽

1996 ◽

Vol 44 (2) ◽

pp. 103-110 ◽

Cited By ~ 2

Author(s):

J.W. Cone ◽

A.H. Van Gelder ◽

A.M. Van Vuuren

Keyword(s):

Organic Matter ◽

Crude Fibre ◽

Fermentation Products ◽

In Situ Method ◽

Degradation Rates ◽

Digestible Organic Matter ◽

Similar Accuracy ◽

The Relationship

The amount of rumen fermentable organic matter (FOM) can be calculated using tables, taking into account the amount of digestible organic matter, the content of fat and fermentation products, and the amount of starch and protein escaping rumen fermentation, or FOM can be calculated using in situ incubations. An in vitro method is described to predict FOM using amylase and other carbohydrate degrading enzymes. FOM estimated by the enzymic method showed a moderate correlation (Rsuperscript 2 = 0.71) with FOM estimated by the in situ method. The relationship could be improved by separating the high crude fibre samples (Rsuperscript 2 = 0.88) from the other samples (Rsuperscript 2 = 0.77). Because degradation rates with the enzymic method were high compared with the assumed rumen passage rates, it proved that FOM could be predicted with a similar accuracy (Rsuperscript 2 = 0.76 - 0.80) by the undegraded fraction after 24 h.

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The Biodiversity–Biomass Relationship of Aquatic Macrophytes Is Regulated by Water Depth: A Case Study of a Shallow Mesotrophic Lake in China

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.650001 ◽

2021 ◽

Vol 9 ◽

Author(s):

Fei Ma ◽

Lei Yang ◽

Tian Lv ◽

Zhenjun Zuo ◽

Haocun Zhao ◽

...

Keyword(s):

Water Depth ◽

Aquatic Macrophyte ◽

Interspecific Interactions ◽

Species Identity ◽

Community Biomass ◽

Macrophyte Communities ◽

Macrophyte Community ◽

Evenness Indices ◽

Aquatic Macrophyte Community ◽

The Relationship

The relationship between biodiversity and productivity (or biomass production) (BPR) has been a popular topic in macroecology and debated for decades. However, this relationship is poorly understood in macrophyte communities, and the mechanism of the BPR pattern of the aquatic macrophyte community is not clear. We investigated 78 aquatic macrophyte communities in a shallow mesotrophic freshwater lake in the middle and lower reaches of the Yangtze River in China. We analyzed the relationship between biodiversity (species richness, diversity, and evenness indices) and community biomass, and the effects of water environments and interspecific interactions on biodiversity–biomass patterns. Unimodal patterns between community biomass and diversity indices instead of evenness indices are shown, and these indicate the importance of both the number and abundance of species when studying biodiversity–biomass patterns under mesotrophic conditions. These patterns were moderated by species identity biologically and water depth environmentally. However, water depth determined the distribution and growth of species with different life-forms as well as species identities through environmental filtering. These results demonstrate that water depth regulates the biodiversity–biomass pattern of the aquatic macrophyte community as a result of its effect on species identity and species distribution. Our study may provide useful information for conservation and restoration of macrophyte vegetation in shallow lakes through matching water depth and species or life-form combinations properly to reach high ecosystem functions and services.

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Abundance and diversity of soil arthropods and fungi in shelterbelts integrated with pastures in the central tablelands of New South Wales, Australia

Journal of Forest Science ◽

10.17221/12/2012-jfs ◽

2012 ◽

Vol 58 (No. 12) ◽

pp. 560-568 ◽

Cited By ~ 1

Author(s):

E.W. Mbuthia ◽

J.H. Shariff ◽

A. Raman ◽

D.S. Hodgkins ◽

H.I. Nicol ◽

...

Keyword(s):

Organic Matter ◽

Biological Diversity ◽

Soil Depth ◽

Soil Surface ◽

Early Spring ◽

Late Winter ◽

Soil Arthropods ◽

South Wales ◽

Abundance And Diversity ◽

The Relationship

Shelterbelts are important for the sustainability of agriculture because they provide a variety of benefits to farmers and the society. Several published papers demonstrate that integration of shelterbelts with agroecosystems offers positive outcomes, such as better yield, more congenial microclimate, and greater organic matter levels. Nonetheless, soil biological diversity, the driver of greater organic matter levels, has not been convincingly tested and verified yet. In addressing this gap, we measured abundance and diversity of populations of arthropods and fungi in three<br />11-year old shelterbelts integrated with pasture to determine whether a correlation exists between the abundance of and diversity in populations of arthropods and fungi in two seasons: late autumn-early winter (May–June 2011) and late winter-early spring (August–September 2011). Litter from the soil surface and soil from two depths were sampled at increasing distance from the midpoint of shelterbelts for the extraction of arthropods and isolation culturing of fungi. The relationship among distance, depth and biodiversity of different groups of arthropods and fungi was analysed using linear regression. We found that over both seasons arthropod abundance in the litter and soil declined with increasing distance from the midpoint of the shelterbelts, and with soil depth. However, fungi abundance in either season was not affected by proximity to the shelterbelt but increased with greater soil depth. Distance from the shelterbelt midpoints did not bear an impact on the diversity richness of both arthropods and fungi.

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Oxygen uptake during mineralization of humic substances from Infernão Lagoon (São Paulo, Brazil)

Brazilian Journal of Biology ◽

10.1590/s1519-69842004000400005 ◽

2004 ◽

Vol 64 (3b) ◽

pp. 583-590 ◽

Cited By ~ 2

Author(s):

M. B. Cunha-Santino ◽

I. Bianchini JR.

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Oxygen Uptake ◽

Dissolved Oxygen ◽

Humic Substances ◽

Aquatic Macrophyte ◽

Uptake Coefficient ◽

First Order ◽

First Order Kinetics ◽

Different Sources

Assays were carried out to evaluate the dissolved oxygen uptake resulting from mineralization of humic substances (fulvic acid (FA) and humic acid (HA)) from different sources: sediment, dissolved organic matter (DOM) of 120-day decomposed aquatic macrophyte (Scirpus cubensis and Cabomba piauhyensis), and lagoon DOM. The experiments were also aimed at estimating the oxygen uptake coefficient of the mineralization. About 20-30 mg of substrate were added to 1.1 liters of water from Infernão Lagoon (21º33' to 21º37'S; 47º45' to 47º51'W). The solutions were aerated and the dissolved oxygen (DO) was monitored during 40 days. Dissolved organic carbon (DOC) and particulate organic carbon (POC) were estimated after 80 days of the experiment. Anaerobic processes were avoided by aerating the solutions. The results were fitted to a first-order kinetics model, from which the uptake of oxygen parameters was obtained. Oxygen consumption (OC) ranged from 4.24 mg L-1 (HA - S. cubensis) to 33.76 mg L-1 (FA - sediment). The highest deoxygenation coefficient (kD) was observed during mineralization of FA - DOM (0.299 day-1), followed in decreasing order by FA - S. cubensis, HA - sediment, HA - S. cubensis, FA - sediment, and FA - C. piauhyensis (0.282; 0.255; 0.178; 0.130, and 0.123 day-1, respectively). The carbon analyses indicated that the FA and HA samples at the end of the experiment presented a decay that varied from 15.23% to 42.35% and that the FA and HA conversions into POC were relatively low (from 0.76% to 3.94%).

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Occurrence and distribution of vermiform plant-parasitic nematodes and the relationship with soil factors in field pea (Pisum sativum) in North Dakota, USA

Nematology ◽

10.1163/15685411-00003225 ◽

2019 ◽

Vol 21 (5) ◽

pp. 445-457 ◽

Cited By ~ 3

Author(s):

Arjun Upadhaya ◽

Guiping Yan ◽

Julie Pasche ◽

Audrey Kalil

Keyword(s):

Organic Matter ◽

Soil Properties ◽

Field Pea ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Soil Factors ◽

The Usa ◽

Nematode Abundance ◽

The Relationship ◽

Plant Parasitic

Summary Plant-parasitic nematodes restrict crop growth and cause yield loss in field pea (dry edible pea). A 4-year survey of commercial pea fields was conducted in North Dakota, one of the leading producers of field pea in the USA, to investigate nematode distribution, prevalence, abundance and association with soil properties. Beginning in 2014, a total of 243 soil samples were collected from 16 counties, and soil properties of 115 samples were analysed to determine the association of nematodes with soil factors (texture, organic matter, nutrients). The plant-parasitic nematode genera, Paratylenchus (absolute frequency = 58-100%; mean density = 470-1550 (200 g soil)−1; greatest density = 7114 (200 g soil)−1) and Tylenchorhynchus (30-80%; 61-261; 1980, respectively), were the most frequent and widely distributed. Pratylenchus and Helicotylenchus were identified in one-third of the counties surveyed with mean densities ranging from 43 to 224 and 36 to 206 (200 g soil)−1, respectively. Xiphinema was found relatively frequently but at low densities. Hoplolaimus and Paratrichodorus were rarely detected at lower densities. Canonical correspondence analysis revealed that soil factors explained 19% of the total variance of nematode genera abundance. The relationship between nematode abundance and soil sand content and pH was significant, while clay, silt, organic matter and nutrients were not significantly related to nematode abundance. This is the first multi-year study investigating nematodes associated with field peas and their relationship with soil factors in a major field pea production region of the USA.

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Patterns of the aquatic macrophyte cover in Cachoeira Dourada Reservoir (GO-MG)

Brazilian Journal of Biology ◽

10.1590/s1519-69842005000100004 ◽

2005 ◽

Vol 65 (1) ◽

pp. 19-24 ◽

Cited By ~ 12

Author(s):

L. M Bini ◽

L. G Oliveira ◽

D. C Souza ◽

P. Carvalho ◽

M. P. Pinto

Keyword(s):

Aquatic Macrophytes ◽

Positive Relationship ◽

Aquatic Macrophyte ◽

Main Body ◽

Frequency Of Occurrence ◽

Frequent Species ◽

Eichhornia Azurea ◽

The Relationship ◽

Macrophyte Cover

The relationship between the aquatic macrophyte cover in upper segments of tributaries and this cover in these tributaries but near the reservoir's main body was tested. Sixteen taxa belonging to 12 families of aquatic macrophytes were recorded in Cachoeira Dourada Reservoir. The most frequent species were Eichhornia azurea (frequency of occurrence = 92%; n = 37 sites) and E. crassipes (44%). Upper segments of the tributaries were the main areas colonized by these aquatic macrophytes. The positive relationship between the aquatic macrophyte cover between the upper and lower segments of tributaries indicates the importance of dispersion in the colonization of the arms and the reservoir's main body.

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