Environmental correlates of coastal heathland and allied vegetation

2008 ◽  
Vol 56 (6) ◽  
pp. 512 ◽  
Author(s):  
S. J. Griffith ◽  
C. Bale ◽  
P. Adam

The east Australian coastline supports regionally distinct heathlands and allied structural formations, and of particular interest is the vegetation on Quaternary dunefields and beach ridge plains containing aquifers. Groundwater is abstracted from these aquifers for domestic, industrial and agricultural consumption, and this abstraction proceeds without a sound understanding of plant–water relations. This study examined relationships between the vegetation and a range of simple and complex environmental variables. Aspects of intra-habitat and micro-site environmental heterogeneity were also explored. Watertable depth varied spatially and temporally relative to vegetation type, although differences were not consistently significant. Differences in watertable depth were significant for vegetation samples grouped by topographic position. Plant roots were invariably present at the upper boundary of the aquifer and these were observed at depths of up to 10.5 m. Groundwater was found to have the chemical composition of dilute seawater. Soil properties for the A1 horizon (total phosphorus, total nitrogen and organic matter content) varied with vegetation type and topography, and although mean values were generally higher in wetter habitats, differences were not consistently significant. Ordination identified topography as the more important determinant of vegetation pattern. Intra-habitat and micro-site differences in soil and groundwater properties were detected, and the likely causes of this variation are discussed.

Revista CERES ◽  
2016 ◽  
Vol 63 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Claudinei Alberto Cardin ◽  
Carlos Henrique dos Santos ◽  
Marcos Antonio Escarmínio

ABSTRACT Soils of tropical regions are more weathered and in need of conservation managements to maintain and improve the quality of its components. The objective of this study was to evaluate the availability of K, the organic matter content and the stock of total carbon of an Argisol after vinasse application and manual and mechanized harvesting of burnt and raw sugarcane, in western São Paulo.The data collection was done in the 2012/2013 harvest, in a bioenergy company in Presidente Prudente/SP. The research was arranged out following a split-plot scheme in a 5x5 factorial design, characterized by four management systems: without vinasse application and harvest without burning; with vinasse application and harvest without burning; with vinasse application and harvest after burning; without vinasse application and harvest after burning; plus native forest, and five soil sampling depths (0-10 10-20, 20-30, 30-40, 40-50 cm), with four replications. In each treatment, the K content in the soil and accumulated in the remaining dry biomass in the area, the levels of organic matter, organic carbon and soil carbon stock were determined. The mean values were compared by Tukey test. The vinasse application associated with the harvest without burning increased the K content in soil layers up to 40 cm deep. The managements without vinasse application and manual harvest after burning, and without vinasse application with mechanical harvesting without burning did not increase the levels of organic matter, organic carbon and stock of total soil organic carbon, while the vinasse application and harvest after burning and without burning increased the levels of these attributes in the depth of 0-10 cm.


1979 ◽  
Vol 59 (1) ◽  
pp. 69-78 ◽  
Author(s):  
C. R. DE KIMPE ◽  
G. R. MEHUYS

Clay-rich soils were sampled in the agricultural areas of Montreal, Quebec and Lake St-Jean. Undisrupted soil blocks and bulk samples were taken by horizon in the Ste-Rosalie, Kamouraska and Normandin soil series. Aggregate stability increased with the organic matter content. Bulk density was generally highest in the B horizons. Porosity ranged from 39 to 56% of the total soil volume and the most representative pore diameter varied from 0.706 to 0.048 μm with the largest diameter being found in the Ap horizons. The distribution of porosity among large, medium and small pores in the Ste-Rosalie soil differed from that in the Kamouraska and Normandin soils. In the former, medium pores accounted for only a few percent of total porosity, while the pores were more evenly distributed in the latter soils. Medium pore contents decreased, while small pore contents increased, with increasing clay contents. No significant relationship was observed between large pores and clay percentages. Hydraulic conductivity, with mean values ranging from 3.5 to 109.3 cm/h, was significantly related to the large pore class.


Botany ◽  
2015 ◽  
Vol 93 (12) ◽  
pp. 825-841 ◽  
Author(s):  
Caitlin Porter ◽  
Jeremy Lundholm ◽  
Tony Bowron ◽  
Ben Lemieux ◽  
Danika van Proosdij ◽  
...  

We numerically classified tidal wetland vegetation and determined the relationships between variation in plant species composition and environmental factors. Sampling was conducted at eight sites along a range of tidal magnitudes (<2 to >14 m). Cluster analysis revealed seven distinct salt or brackish marsh plant associations, usually dominated by a single graminoid species. Redundancy analysis showed continuous variation among community units and identified inundation time, elevation, soil salinity, and organic matter content as key correlates of plant community patterns. Associations detected were similar to those found in New Brunswick’s Bay of Fundy and Northumberland Strait wetlands, and to those farther south in northern New England, but two new brackish associations were also identified within this study (Juncus balticus Willd. – Festuca rubra L. and Spartina pectinata Link). Although elevation is understood to drive vegetation types in salt marshes in the region, here we show that salinity can differentiate vegetation types at the same elevation. These data provide a quantitative baseline and allow for better predictions of tidal wetland ecological restoration trajectories in Nova Scotia.


1999 ◽  
Vol 59 (1) ◽  
pp. 23-31 ◽  
Author(s):  
F. L. M. MANTELATTO ◽  
A. FRANSOZO

The objective of the present study is to characterize the physical and chemical environmental parameters of Ubatuba Bay (SP), as a subsidy for studies of the composition and distribution of benthic crustaceans which live on the non-consolidated sublittoral bottom of this area. Depth, temperature, salinity, dissolved oxygen, organic content and granulometric composition of the sediments were measured monthly from September/95 to August/96 in eight subareas of the bay. The bay presents an average depth of 9.3 m and is characterized by the following annual mean values for the hydrologic factors: temperature 23.8 ºC, salinity 33.2‰ and dissolved oxygen 5.11 mg/l. The annual mean for the organic matter content of the bay bottom sediments was 11.8% and most subareas presented a grain size composition dominated by pelitic sediments. These peculiar abiotic characteristics are very important for the reproduction and development principally of brachyuran and anomuran crabs, and shrimps which have a close relationship with those substrates.


2017 ◽  
Vol 78 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota ◽  
Maciej Zwydak

Abstract The aim of this study was to assess the effects of different types of land use (forest, tillage and pasture) on soil properties, especially enzyme activity. Our investigation was carried out on 53 research plots with 11 plots in broadleaved forest stands, 12 plots in mixed broadleaved stands, 10 plots in mixed coniferous stands, 9 plots on tillage and 11 plots on pasture. The soil samples were collected from a depth of 0–15 cm after removing the organic horizon. Contents of organic carbon and nitrogen, pH and soil texture were investigated. Furthermore, dehydrogenase and urease activity were determined. Significant differences in the enzyme activity between forest and agricultural soils were observed, thus demonstrating that enzyme activity is influenced by the organic matter content of the soil. The highest enzyme activity was recorded in the forest soil within broadleaved stands, whilst the lowest activity was found in tillage soil, because tillage soil contained significantly less organic matter. High enzymatic activity of pasture soils is the combined result of vegetation type and the lack of plowing.


Author(s):  
C. Nwakanma ◽  
C. Nmecha ◽  
R.U. Onyeizu

This study assessed the concentrations of heavy metals in soil and surface water from a Lead-Zinc mined pit at Enyigba, Ikwo Local Government Area in Ebonyi State, Nigeria. Soil samples were collected and analysed from different soil depths (0 – 15 cm) and (15 – 30 cm) at a tailing down (marked as TD) and refuse dumpsite (marked as RD) and a vegetation site 50 km away which was used as the control site. Surface water samples were collected from the Enyigba River from three (3) points (marked as point A, B, and C) and were analysed using routine laboratory procedures. The following parameters were analysed for soil: particle size distribution, pH, available phosphorus, total nitrogen, organic carbon, organic matter content, calcium, magnesium, potassium, sodium, exchangeable acidity, and effective cation exchange capacity. The results for mean values of soil samples obtained at both depths were 58.86% (sand), 11.73% (silt) and 34.04% (clay). Mean values obtained for heavy metals from the soil for Iron (Fe) ranged from 3.31 to 2.24 mg/kg: Zinc (Zn) 0.70 to 0.62 mg/kg and Lead (Pb) 0.01 to 0.01 mg/kg). Results obtained for surface water around the mined pit showed mean values for Iron (Fe) 0.57 mg/L, Magnesium (Mg) 151.6 mg/L, Calcium (Ca) 76.62 mg/L, Chlorine (Cl2) 416.6 mg/L and Lead (Pb) 0.01 mg/L. The high concentrations of chlorine make the water unsuitable to be discharged on any agricultural land as plants could accumulate these metals and when consumed could pose serious threat to humans. The discharge from the mining site increased the already slightly high turbidity of the water to a much higher and undesirable level. The mining activity at Enyigba Ikwo LGA, Ebonyi State has negatively impacted the environment through the introduction of heavy metals in soil and surface water, thereby causing an increase in the pollution of the environment. It is recommended that further studies and monitoring should be carried out in the study location for possible remediation.


2016 ◽  
Vol 46 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Maria Regina de Miranda Souza ◽  
Paulo Roberto Gomes Pereira ◽  
Ivan de Paiva Barbosa Magalhães ◽  
Maria Aparecida Nogueira Sediyama ◽  
Sanzio Mollica Vidigal ◽  
...  

ABSTRACT Considering that nitrogen is directly related to leaf protein content, the nitrogen fertilization in Pereskia aculeata plants may affect the protein content and increase its nutritional potential. This study aimed at assessing the effect of nitrogen fertilization on mineral, protein and nitrate contents, as well as the yield of P. aculeata leaves. A randomized blocks design was used, with three replications and five treatments, consisting of increasing topdressing nitrogen doses (0-400 kg ha-1), in soil with organic matter content of 4.0 dag kg-1. Three harvests were performed for leaf analysis. No significant effect was observed for mineral and protein content or leaf fresh mass yield. The mean values for mineral composition were: 3.52 dag kg-1 of N, 0.47 dag kg-1 of P, 4.65 dag kg-1 of Ca, 0.71 dag kg-1 of Mg, 0.25 dag kg-1 of S, 36.64 mg kg-1 of Zn and 174.13 mg kg-1 of Fe. The mean content for protein was 21.86 % and the leaf fresh mass yield was 0.971 kg plant-1. K levels decreased from 50 kg ha-1 of N. Nitrate increased linearly with the nitrogen fertilization, reaching a maximum value of 78.2 mg kg-1 of fresh mass, well below the health risk threshold. It was concluded that a soil with high organic matter content does not require nitrogen fertilization. However, doses up to 400 kg ha-1 of nitrogen ensure adequate leaf yield and protein and mineral contents within the desired range for the species, being a food rich in proteins, iron and calcium.


2020 ◽  
Vol 32 ◽  
Author(s):  
Gustavo Ruschel Lopes ◽  
Hugo Mendes de Oliveira ◽  
Gabriel Fernandes Alves de Jesus ◽  
Maurício Laterça Martins ◽  
Carlos Henrique Araújo de Miranda Gomes ◽  
...  

Abstract: Aim The increment of decomposition of organic matter in sediment samples from Nile tilapia farms was evaluated with the introduction of Bacillus subtilis and B. licheniformis bacteria. Methods Sediment samples placed in 18L plastic boxes received single dose inoculum with the following concentrations: 1.21 x 106 CFU g-1 (equivalent to 75 g ha-1), 2.41 x 106 CFU g-1 (equivalent to 150 g ha-1), 4.82 x 106 CFU g-1 (equivalent to 300 g ha-1) and 1.61 x 107 CFU g-1 (equivalent to 1000 g ha-1), in addition to a control treatment with saline solution only. Organic matter content, total organic carbon (TOC) and oxidizable (OOC), total nitrogen (TN), ratios (TOC: N and OOC: N), clay content, pH in water, Shoemaker, McLean, Pratt index (SMP Index), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) contents, potential acidity (H + Al), cation exchange capacity (CEC) at pH 7.0, base saturation (V) and sum of bases (S). Results The values of OM showed significant difference, between the lowest values (treatments 75, 150 and 300 g ha-1) and the highest value, (control treatment). TOC, OOC, NT and their relationships (TOC: N and OOC: N) showed significant differences between the mean values of the control treatment and the other treatments. Conclusions The addition of Bacillus subtilis and B. licheniformis bacteria increased the decomposition rate of organic matter in sediments samples from Nile tilapia farms.


Author(s):  
O. A. Lipatnikova

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.


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