The role of Sphagnum fimbriatum in secondary succession in a road salt impacted bog

1987 ◽  
Vol 65 (11) ◽  
pp. 2270-2275 ◽  
Author(s):  
Douglas A. Wilcox ◽  
Richard E. Andrus
Keyword(s):  
Secondary Succession ◽  
Vegetative Reproduction ◽  
Salt Content ◽  
Laboratory Studies ◽  
Pore Waters ◽  
Deicing Salts ◽  
Salt Gradient ◽  
Belt Transect ◽  
Sphagnum Fimbriatum

Secondary succession of Sphagnum mosses was studied for 7 years along a belt transect in a bog that had been impacted by sodium chloride highway deicing salts. Laboratory studies on Sphagnum fimbriatum Wils., the dominant recolonizing species, were conducted to determine its salt tolerance level and ability to reproduce from spores and fragments across a salt gradient. Vegetative reproduction was also compared with that of four other recolonizing species. Sphagnum fimbriatum represented a high percentage of all recolonizing Sphagnum and generally began growing on low hummocks in quadrats where the salt content of the interstitial peat pore waters had dropped to about 300 mg/L as chloride. This salt concentration was also found to be the basic tolerance limit for mature plants and reproducing spores and fragments. The success of Sphagnum fimbriatum as a pioneer species seems to be associated with its prolific production and probable dispersal of spores, its superior vegetative reproduction, its tolerance of mineralized waters, and its ability to grow on hummocks out of direct contact with mineralized waters.

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.

scholarly journals The Role of Lower Crustal Rheology in Lithospheric Delamination During Orogeny

2021 ◽  
Vol 9 ◽  
Author(s):  
Lin Chen
Keyword(s):  
Lower Crust ◽  
Numerical Models ◽  
The Tibetan Plateau ◽  
Mantle Lithosphere ◽  
Laboratory Studies ◽  
Surface Uplift ◽  
Continental Lower Crust ◽  
Lower Crustal ◽  
Flow Laws

The continental lower crust is an important composition- and strength-jump layer in the lithosphere. Laboratory studies show its strength varies greatly due to a wide variety of composition. How the lower crust rheology influences the collisional orogeny remains poorly understood. Here I investigate the role of the lower crust rheology in the evolution of an orogen subject to horizontal shortening using 2D numerical models. A range of lower crustal flow laws from laboratory studies are tested to examine their effects on the styles of the accommodation of convergence. Three distinct styles are observed: 1) downwelling and subsequent delamination of orogen lithosphere mantle as a coherent slab; 2) localized thickening of orogen lithosphere; and 3) underthrusting of peripheral strong lithospheres below the orogen. Delamination occurs only if the orogen lower crust rheology is represented by the weak end-member of flow laws. The delamination is followed by partial melting of the lower crust and punctuated surface uplift confined to the orogen central region. For a moderately or extremely strong orogen lower crust, topography highs only develop on both sides of the orogen. In the Tibetan plateau, the crust has been doubly thickened but the underlying mantle lithosphere is highly heterogeneous. I suggest that the subvertical high-velocity mantle structures, as observed in southern and western Tibet, may exemplify localized delamination of the mantle lithosphere due to rheological weakening of the Tibetan lower crust.

scholarly journals Biogeochemical processes in sediments of the Manfredonia Gulf (Southern Adriatic Sea): early diagenesis of carbon and nutrient and benthic exchange

2004 ◽  
Vol 1 (1) ◽  
pp. 803-823 ◽  
Author(s):  
F. Spagnoli ◽  
G. Bartholini ◽  
M. Marini ◽  
P. Giordano
Keyword(s):  
Adriatic Sea ◽  
Water Interface ◽  
Biogeochemical Processes ◽  
Pore Waters ◽  
Dissolved Nutrients ◽  
Dissolved Iron ◽  
High Sedimentation ◽  
Western Adriatic Current ◽  
A Site

Abstract. In order to understand the mechanisms responsible of the recycle of carbon and nutrients at the sediment-water interface and to understand the role of sediments in nutrients mass balance in coastal water, cores were collected (pore waters and solid phases) and benthic fluxes (oxygen, dissolved nutrients, dissolved iron and managanese, alkalinity and TCO2) were measured in two stations in the Gulf of Manfredonia (Southern Adriatic Sea). Stations were chosen to include a site, in the offshore part of the gulf, under the influence of western Adriatic current and another site, in the inner part of the gulf, under influence of gyres occurring inside the gulf. Both stations were placed in areas characterized by high sedimentation rate. Fluxes at sediment water interface show higher values in S2 site during the summer. Bio-irrigation seems to be the main transport mechanism characterizing both sites, with more evident effects during summer in S1 site.

scholarly journals It’s Important to Go to the Laboratory: Malte Ziewitz Talks with Michael Lynch

2018 ◽  
Vol 4 ◽  
pp. 366 ◽  
Author(s):  
Malte Ziewitz ◽  
Michael Lynch
Keyword(s):  
Social Studies ◽  
Science And Technology Studies ◽  
Blow Up ◽  
Science And Technology ◽  
Laboratory Studies ◽  
Technology Studies ◽  
Social Studies Of Science ◽  
Origin Stories

Why would anyone still want to go to the laboratory in 2018? In this interview, Michael Lynch answers this and other questions, reflecting on his own journey in, through, and alongside the field of science and technology studies (STS). Starting from his days as a student of Harold Garfinkel’s at UCLA to more recent times as editor of Social Studies of Science, Lynch talks about the rise of origin stories in the field; the role of ethnomethodology in his thinking; the early days of laboratory studies; why “turns” and “waves” might better be called “spins”; what he learned from David Edge; why we should be skeptical of the presumption that STS enhances the democratization of science; and why it might be time to “blow up STS”––an appealing idea that Malte Ziewitz takes up in his reflection following the interview.

scholarly journals The role of ticks in the maintenance and transmission of Crimean-Congo hemorrhagic fever virus: A review of published field and laboratory studies

2017 ◽  
Vol 144 ◽  
pp. 93-119 ◽  
Author(s):  
Aysen Gargili ◽  
Agustin Estrada-Peña ◽  
Jessica R. Spengler ◽  
Alexander Lukashev ◽  
Patricia A. Nuttall ◽  
...  
Keyword(s):  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Laboratory Studies ◽  
Crimean Congo Hemorrhagic Fever ◽  
Hemorrhagic Fever Virus

The Role of Metabolic Epidemiology and Laboratory Studies in the Etiology of Colon Cancer

Epidemiology ◽  
1979 ◽  
pp. 53-61
Author(s):  
Gary M. Williams ◽  
Bandaru S. Reddy ◽  
John H. Weisburger
Keyword(s):  
Colon Cancer ◽  
Laboratory Studies

scholarly journals Noble Gases in Terrestrial Planets: Evidence for Cometary Impacts?

1989 ◽  
Vol 116 (1) ◽  
pp. 429-437
Author(s):  
Tobias Owen ◽  
Akiva Bar-Nun ◽  
Idit Kleinfeld
Keyword(s):  
Low Temperatures ◽  
Noble Gases ◽  
Noble Gas ◽  
Terrestrial Planets ◽  
Laboratory Studies ◽  
The Impact ◽  
Gas Patterns ◽  
Atmosphere Of Venus

AbstractThe possible role of comets in bringing volatiles to the inner planets is investigated by means of laboratory studies of the ability of ice to trap gases at low temperatures. The pattern of the heavy noble gases formed in the atmosphere of Venus can be explained by the impact of a planetesimal composed of ices formed in the range of 20 to 30 K. The noble gas patterns on Mars and Earth are less explicable by cometary bombardment alone.

scholarly journals A multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Melissa A. Lombard ◽  
Pamela J. Lombard ◽  
Craig J. Brown ◽  
James R. Degnan
Keyword(s):  
New Hampshire ◽  
Salt Content ◽  
Specific Conductance ◽  
Boosted Regression Trees ◽  
Factors Affecting ◽  
Rock Fill ◽  
Deicing Salts ◽  
Geochemical Models ◽  
Roadway Construction ◽  
Physicochemical Data

AbstractFactors affecting iron fouling in wet areas adjacent to roadways were investigated by collecting field rock cut and aqueous physicochemical data; developing exploratory predictive models; and developing geochemical models. Basic data included the identification of iron fouling from aerial imagery and field visits at 374 New Hampshire rock cut locations, and their associated rock-fill sites. Based on field water quality measurements from wet areas at 36 of the rock-fill sites, the occurrence of iron fouling was associated with higher values of specific conductance, lower concentrations of dissolved oxygen and lower pH compared to areas without iron fouling. A statistical model, using boosted regression trees, was developed to predict the occurrence of iron fouling in wet areas adjacent to roadways where rock-fill from nearby rock cuts was used in roadway construction. The model was used to develop a continuous iron fouling probability map for the state of New Hampshire that can be used to better understand the occurrence of iron fouling. Geochemical models illustrate how iron fouling of waters increases along roadways built with fill from sulfidic rock cuts as a result of acid generation from pyrite dissolution and ferrous iron (Fe2+) oxidation and increases in areas with greater specific conductance from deicing runoff caused by cation exchange. More iron is precipitated as goethite in simulations that include pyrite, and in simulations with deicing salts added, indicating that rock-fill sites with rocks that contain pyrite and water with greater salt content could have enhanced iron fouling.

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