Pleistocene–Holocene environmental change in the Canary Archipelago as inferred from the stable isotope composition of land snail shells

2011 ◽  
Vol 75 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Yurena Yanes ◽  
Crayton J. Yapp ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Julio De-la-Nuez ◽  
...  
Keyword(s):  
Environmental Change ◽  
Canary Islands ◽  
Environmental Changes ◽  
Isotope Composition ◽  
Moving Average ◽  
Land Snail ◽  
Balance Model ◽  
Low Latitude ◽  
The Times

AbstractThe isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28–29°N) over the last ~ 50 ka. Shell δ13C values range from −8.9‰ to 3.8‰. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3‰ higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from −1.9‰ to 4.5‰, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1‰ at ~ 50 ka to 1.6–1.8‰ during the LGM (~ 15–22 ka). Subsequently, the moving average δ18O values range from 0.0‰ at ~ 12 ka to 0.9‰ at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.

scholarly journals Long-term sustainability of a worksite canteen intervention of serving more fruit and vegetables

2010 ◽  
Vol 13 (10) ◽  
pp. 1647-1652 ◽  
Author(s):  
Anne V Thorsen ◽  
Anne D Lassen ◽  
Inge Tetens ◽  
Ole Hels ◽  
Bent E Mikkelsen
Keyword(s):  
Environmental Change ◽  
Environmental Changes ◽  
Food Choices ◽  
Fruit And Vegetables ◽  
Average Increase ◽  
Self Monitoring ◽  
Long Term Follow Up ◽  
Waste Handling

AbstractObjectiveTo analyse the 5-year sustainability of a worksite canteen intervention of serving more fruit and vegetables (F&V).DesignAverage F&V consumption per customer per meal per day was assessed in five worksite canteens by weighing F&V served and subtracting waste. Data were collected by the canteen staff during a 3-week continuous period and compared to data from the same five canteens measured at baseline, at end point and at 1-year follow-up. The intervention used a participatory and empowering approach, self-monitoring and networking among the canteen staff, management and a consultant. The method focused on providing ideas for increased F&V for lunch, making environmental changes in the canteens by giving access to tasteful and healthy food choices and reducing the availability of unhealthy options.SettingFive Danish worksites serving from 50 to 500 meals a day: a military base, an electronic component distributor, a bank, a town hall and a waste-handling facility.SubjectsWorksite canteen managers, canteen staff.ResultsFour of the five worksite canteens were able to either maintain the intervention or even increase the consumption of F&V. The average increase from baseline to 5-year follow-up was 95 g per customer per meal per day (18, 144, 66, 105 and 141 g, respectively). On average, the five canteens at the long-term follow-up had an F&V consumption of 208 g/meal per customer.ConclusionsThe present study indicates that sustainability of F&V is possible in worksites where the participatory and empowering approach, self-monitoring, environmental change, dialogue with suppliers and networking among worksite canteens are applied.

Paleoenvironment of the Folsom archaeological site, New Mexico, USA, approximately 10,500 14C yr B.P. as inferred from the stable isotope composition of fossil land snail shells

2005 ◽  
Vol 63 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Meena Balakrishnan ◽  
Crayton J. Yapp ◽  
David J. Meltzer ◽  
James L. Theler
Keyword(s):  
New Mexico ◽  
Stable Isotope ◽  
Relative Humidity ◽  
Isotope Composition ◽  
Younger Dryas ◽  
Archaeological Site ◽  
Land Snail ◽  
Climatic Changes ◽  
Stable Isotope Composition ◽  
The Times

Well-preserved aragonitic land snail shells (Vallonia) from late Pleistocene Eolian sediment in the Folsom archaeological site in New Mexico exhibit an overall decrease of δ18OPDB from maximum values of +2.7‰ (more positive than modern) to younger samples with lower average values of about −3.6‰ (within the modern range). The age of the samples (approximately 10,500 14C yr B.P.) suggests that the decrease in δ18O may manifest climatic changes associated with the Younger Dryas. Some combination of increased relative humidity and cooler temperatures with decreased δ18O of precipitation during the times of snail activity can explain the decrease in shell δ18O. A well-known Paleoindian bison kill occurred at the Folsom site during this inferred environmental transition.Average δ13C values of the aragonite shells of the fossil Vallonia range from −7.3 to −6.0‰ among different archaeological levels and are not as negative as modern values. This suggests that the proportion of C4 vegetation at the Folsom site approximately 10,500 14C yr B.P. was greater than at present; a result which is consistent with other evidence for higher proportions of C4 plants in the region at that time.

Paleoenvironmental implications of carbon stable isotope composition of land snail tissues

2013 ◽  
Vol 80 (3) ◽  
pp. 596-605 ◽  
Author(s):  
Yurena Yanes ◽  
María P. Asta ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Christopher S. Romanek
Keyword(s):  
Isotope Composition ◽  
Isotope Analysis ◽  
Land Snail ◽  
Balance Model ◽  
Metabolic Rates ◽  
Stable Isotope Composition ◽  
Cam Plants ◽  
Shell Size ◽  
Flux Balance ◽  
C Value

Land snail shell δ13C value is often used as a paleovegetation proxy assuming that snails ingest all plants in relation to their abundance, and that plants are the only source of carbon. However, carbonate ingestion and variable metabolic rates complicate these relationships. We evaluate if live-collected snails from Lanzarote (Canary Islands) reflect the abundance of C3 and CAM plants. Snails were collected on either CAM or C3 plants for isotope analysis of shell and body, and shell size. Respective shell and body δ13C values of snails collected on CAM plants averaged − 8.5 ± 1.7‰ and − 22.8 ± 1.6‰, whereas specimens from C3 plants averaged − 10.1 ± 0.7‰ and − 24.9 ± 1.1‰. A flux balance model suggests snails experienced comparable metabolic rates. A two-source mass balance equation implies that snails consumed ~ 10% of CAM, which agrees with their abundance in the landscape. Snails collected on CAM plant were smaller than those on C3 plants. Conclusively: 1) snails consume CAM plants when they are available; 2) migration of snails among C3 and CAM plants is a common phenomenon; and 3) C3 plants may be a more energetic food for growth than CAM plants. This study shows that shell δ13C values offer approximate estimates of plants in C3–CAM mixed environments.

scholarly journals Holocene DNA sequences – a dream come true

2018 ◽  
Author(s):  
Anushree Sanyal ◽  
Josefine Larsson ◽  
Falkje van Wirdum ◽  
Thomas Andrén ◽  
Matthias Moros ◽  
...  
Keyword(s):  
Environmental Change ◽  
Baltic Sea ◽  
Dna Sequences ◽  
Environmental Changes ◽  
Sequence Data ◽  
Marine Diatom ◽  
Long Term Effects ◽  
Chaetoceros Muelleri ◽  
Resting Spores

AbstractMicroscopic marine planktons have played a major role in the Earth’s ecosystem and accounts for half the globe’s primary production. Predicting the fate of marine planktons is imperative to understanding how ocean life will change in future centuries and how organisms have adapted to changes in the past over long timescales (over thousands of years). Studies of revived resting spores of marine diatoms will serve as excellent proxies of environmental change in marine environments. Thus far, only about a century old marine diatom resting spores could be revived. This severely limited the use of diatom resting spores to investigate the effects of environmental perturbations over longer time scales. Here, we, for the first time report revival of thousands of years old resting spores from the deposits of ancient diatoms (Chaetoceros) in sub-seafloor sediments using a revival protocol that involved recreating the ancient environmental conditions (salinity, temperature and light). Our revived diatom resting spores samples range from recent (0-80 years) to ∼7200 years old. Importantly, we also extracted the DNA from the ancient resting spores of Chaetoceros species from the Baltic Sea. Our findings will enable us to compare DNA sequence data obtained from these natural archives of resurrected organisms and provide predictive models to forecast evolutionary responses of natural populations to environmental changes resulting from natural and anthropogenic stressors, including climate changeSignificance StatementOur results address the important topic of adaptive evolution in marine species due to climate and environmental change induced due to anthropogenic perturbations. We present a new model system Chaetoceros muelleri which will help us address important evolutionary and long-term adaptation questions across evolutionary timescales. Our study reports (1) the revival of recent (0-80 years) to ancient (7200 years old) resting spores of Chaetoceros (2) the extraction of DNA and amplification of chloroplast and ribosomal genes from recent and ancient (∼1300 years old) resting spores of Chaetoceros (3) Radiocarbon dating to determine age of sediments (4) Identification of species by reviving the resting spores (5) Baltic sea an excellent ecosystem to study long-term effects of environment on species adaptation

Response of past and present Mediterranean ecosystems to environmental change

2003 ◽  
Vol 27 (3) ◽  
pp. 359-377 ◽  
Author(s):  
Harriet D. Allen
Keyword(s):  
Environmental Change ◽  
North Atlantic ◽  
Environmental Changes ◽  
Mediterranean Ecosystems ◽  
Anthropogenic Activity ◽  
Relative Impact ◽  
Ecosystem Response ◽  
Contemporary Climate ◽  
Mediterranean Type Ecosystems

Mediterranean ecosystems contain some of the highest levels of plant diversity of any region on Earth and are amongst those believed to be most at risk from the consequences of global warming. Yet such ecosystems are not static and have responded to environmental changes at a variety of scales and from a variety of causes, particularly climatic and anthropogenic. The purpose of this paper is to review recent research on environmental change and ecosystem response. Long-term records are available to analyse changes over glacial-interglacial cycles, while high resolution records show the sensitivity and coupling of Mediterranean, North Atlantic and Greenland records. For the Holocene, there is continued debate about the relative impact of anthropogenic activity, but there is also increasing recognition that mediterranean-type ecosystems should not be regarded as fragile, degraded landscapes, but are disturbance- adapted. Nevertheless, conservation measures face increasing challenges from contemporary climate change and human pressures. Some insights into the identification of refugial areas, either in glacial times or for present-day conservation purposes, come from molecular Biogeographical studies of past faunal and floral distribution.

Hydrogeological responses in tropical mountainous springs

2019 ◽  
Author(s):  
Ricardo Sánchez-Murillo
Keyword(s):  
Costa Rica ◽  
Isotope Composition ◽  
Central Valley ◽  
Distribution Functions ◽  
Geochemical Composition ◽  
Transit Times ◽  
Management Plans ◽  
Best Fit ◽  
Term Data

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.

Designing a CRM Framework for online & offline sports footwear retailers

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes
Keyword(s):  
Environmental Changes ◽  
Customer Relationship ◽  
Business Strategies ◽  
Economic Sectors ◽  
Running Shoes ◽  
Brick And Mortar ◽  
Key Factor ◽  
On Line ◽  
The Impact

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.

Sign in / Sign up

Export Citation Format

Share Document