Soil selenium in a forested seabird colony: distribution, sources, uptake by plants, and comparison with non-seabird sites

Soil Research ◽  
2012 ◽  
Vol 50 (7) ◽  
pp. 588 ◽  
Author(s):  
David J. Hawke ◽  
Jun-Ru Wu

Seabirds vector selenium (Se) into terrestrial ecosystems in Antarctica and on tropical coral islands, but factors controlling distribution within affected soils are unknown, especially in temperate regions. At a Westland petrel (Procellaria westlandica) breeding colony on mainland New Zealand, the concentration of Se in petrel guano (3.6 mg kg–1) exceeded soil parent material (0.8 mg kg–1) and in all but two soil samples (range 1.2–4.2 mg kg–1; n = 52). External Se (Se not derived from parent material) accounted for 64 ± 9% (mean ± s.d.) of soil Se. Measurements were also made at a former seabird breeding site, and at a site with no Holocene seabird breeding. Median surface-soil Se concentrations (mg kg–1) were in the order burrow soil (2.6) > adjacent forest floor (2.2) > former breeding site (1.0) > control site (0.2), with significant differences between burrow soil and (1) the former breeding site and (2) the control site. In a linear regression model, soil pH, and δ15N were the only significant predictors of external Se in colony soil. The correlations are consistent with seabird input driving both the Se supply and increased sorptive uptake in an environment acidified by seabird guano. Despite the enhanced Se in colony soil, median foliage concentrations (tree fern 0.05 mg kg–1, nikau 0.08 mg kg–1) were close to the accepted minimum for herbivore nutrition. Seabirds therefore contribute significant Se to breeding colony soils in temperate areas, but this is not necessarily transferred to plant foliage.

2017 ◽  
Vol 23 (9) ◽  
pp. 3808-3824 ◽  
Author(s):  
Laurent Augusto ◽  
David L. Achat ◽  
Mathieu Jonard ◽  
David Vidal ◽  
Bruno Ringeval

Author(s):  
Yiwei Zhao ◽  
Liangmin Gao ◽  
Fugeng Zha ◽  
Xiaoqing Chen ◽  
Xiaofang Zhou ◽  
...  

AbstractDue to the special sensitivity of typical ecologically fragile areas, a series of human life, mining, and other activities have a greater impact on the environment. In this study, three coal mines in Ordos City on the Loess Plateau were selected as the study area, and the pollution levels of heavy metals in the area were studied by measuring As, Hg, Cr, Cd, Cu, Ni, and Pb in the soil of 131 sampling points. Combined with the concept of “co-occurrence network” in biology, the level of heavy metals in soil was studied using geostatistics and remote sensing databases. The results showed that the concentrations of Hg, Cr, Ni, Cu, and Pb in more than half of the sampling points were higher than the local environmental background value, but did not exceed the risk control value specified by China, indicating that human factors have a greater influence, while Cd and As elements are mainly affected Soil parent material and human factors influence. Heavy metal elements have nothing to do with clay and silt but have an obvious correlation with gravel. Cd, Pb, As and Ni, Cd, Cr are all positively correlated, and different heavy metals are in space The distribution also reflects the autocorrelation, mainly concentrated in the northeast of the TS mining area and the middle of the PS mining area.


2000 ◽  
Vol 30 (8) ◽  
pp. 1196-1205 ◽  
Author(s):  
J R Williamson ◽  
W A Neilsen

Soil compaction has been considered a principal form of damage associated with logging, restricting root growth and reducing productivity. The rate and extent of soil compaction on skid trails was measured at six field locations covering a range of dry and wet forests. Data was collected for up to 21 passes of a laden logging machine. A similar extent of compaction, averaging 0.17 g·cm-3 increase in total soil bulk density (BD), was recorded for all field sites despite substantial site and soil differences. On average, 62% of the compaction in the top 10 cm of the soil occurred after only one pass of a laden logging machine. The environment under which soils had formed played a major role in determining the BD of the undisturbed soil. Compaction was strongly related to the original BD, forest type, and soil parent material. Soil strengths obtained in the field fell below levels found to restrict root growth. However, reduction in macropores, and the effect of that on aeration and drainage could reduce tree growth. On the wettest soils logged, machine forces displaced topsoils rather than causing compaction in situ. Recommended logging methods and implications for the development of sustainability indices are discussed.


1960 ◽  
Vol 40 (2) ◽  
pp. 121-129 ◽  
Author(s):  
J. A. McKeague ◽  
C. F. Bentley

Plastic columns containing a calcareous clay loam soil parent material with and without ground aspen leaves at the surface were maintained under different drainage conditions for 32 months. Distilled water was added at regular intervals. Results of redox potential (Eh) measurements at four depths, leachate analysis and analysis of the soil material are presented.With water table to the surface and a layer of surface leaves, low Eh readings and appreciable iron movement resulted. In a column with fluctuating water table and surface leaves, raising the water table brought about a decrease in the Eh of the soil below the water table. Height of water table had no effect on the Eh of a column which had no leaves at the surface. In columns where the soil material was mixed with quartz sand, leaching brought about marked downward movement of silt and clay size particles. Apart from the removal of soluble salts, there was little measurable change in columns which had no admixture of sand.


2007 ◽  
Vol 34 (8) ◽  
pp. 616 ◽  
Author(s):  
Amanda J. Dare ◽  
Paul G. McDonald ◽  
Michael F. Clarke

Bell miner (Manorina melanophrys) colonies are closely associated with decreased avian abundance and diversity and an apparently associated increase in psyllid abundance. However, a causative link between the presence of bell miners and increased psyllid abundance has yet to be established. We took advantage of the movement of bell miners into two new areas to investigate the ecological consequences of bell miner occupation on both avian and psyllid abundance. We monitored the number of bell miners and other avian species, using area searches, and psyllid abundance by monthly counts of lerp on leaves. Bell miner presence alone had limited effect on either bird diversity or abundance. However, when miners were also giving their distinctive ‘tink’ vocalisation, a significant decrease in avian abundance and diversity was observed. This evidence supports the hypothesis that ‘tink’ vocalisations are used by interspecific competitors to detect bell miner colonies. At the time of initial occupation, new sites did not have significantly elevated levels of psyllids compared with surrounding areas unoccupied by bell miners. Six months later one of the two newly occupied sites had significantly more Cardiaspina spp. than either the long-established colony or an unoccupied control site. In contrast, infestations of Glycaspis spp. remained significantly lower at both new sites when compared with the long-established colony, but equivalent to unoccupied areas. Given this, we conclude that bell miner occupation does not necessarily lead to an increase in psyllid abundance, characteristic of tree dieback in some colonies, and that a causative link between bell miner presence and declining tree health remains to be demonstrated.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Antonio Scarano ◽  
Felice Lorusso ◽  
Lorenzo Ravera ◽  
Carmen Mortellaro ◽  
Adriano Piattelli

Background. Oral rehabilitation of partially fully edentulous patients with dental implants has become a routine procedure in clinical practice. In a site with a lack of bone GBR is a surgical procedure that provides an augmentation in terms of volume for the insertion of dental implants.Materials and Methods. In the iliac crest of six sheep 4 defects were created where an implant was inserted, three of them with different biomaterials and a control site. All animals were sacrificed after a 4-month healing period. All specimens were processed and analyzed with histomorphometry. Statistical evaluation was done to evaluate percentage of bone defect filled by new bone.Results. All experimental groups showed an increase of the new bone. Higher and highly statistically significant differences were found in the percentages of bone defect filled by new bone in group filled with corticocancellous 250–1000 microns particulate porcine bone mix.Conclusions. This study demonstrates that particulate porcine bone mix and porcine corticocancellous collagenate prehydrated bone mix when used as scaffold are able to induce bone regeneration. Moreover, these data suggest that these biomaterials have higher biocompatibility and are capable of inducing faster and greater bone formation.


Geoderma ◽  
2019 ◽  
Vol 338 ◽  
pp. 247-258 ◽  
Author(s):  
Yun Zhang ◽  
Mulualem Tigabu ◽  
Zhigang Yi ◽  
Huitong Li ◽  
Zheng Zhuang ◽  
...  

Behaviour ◽  
1992 ◽  
Vol 123 (3-4) ◽  
pp. 194-219 ◽  
Author(s):  
Bridget J. Stutchbury ◽  
Steve Zack

AbstractIn many avian societies, young birds delay breeding beyond the age of sexual maturity. Most previous hypotheses of delayed breeding have emphasized forces that keep young birds from becoming breeders. We develop a model of delayed breeding which includes the future acquisition of a high quality territory as a potential direct benefit of delayed breeding. Strong differences in territory quality, age-correlated asymmetries in resource holding potential, and territory site tenacity set the stage for young birds to either breed immediately on a poor territory, or obtain a high quality territory through reproductive delay on or near the site. A wide variety of species and social organizations reveal common patterns of breeding status acquisition through behaviours as nonbreeders with site tenacity on or immediately near the breeding site. A review of 'floater' strategies reveals that nonbreeders frequently have restricted home ranges that encompass one or more breeding territories, and prior experience at a site improves their chances of acquiring a territory in future years. This pattern of territory acquisition argues for incorporating direct benefits into models of delayed breeding. We discuss the potential applications to understanding delayed breeding in social systems as apparently different as cooperatively-breeding birds, migratory passerines, colonial breeding gulls, and lek-breeding grouse and manakins.


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