topic:"Ecosystem" found 1545 records • Arctic Health

Author Affiliation: Vector Borne Diseases and International Health Section, Department of Infectious, Parasitic, and Immuno-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy. marco.diluca@iss.it

Source: Vector Borne Zoonotic Dis. 2009 Dec;9(6):703-11

Date: Dec-2009

Language: English

Publication Type: Article

Keywords: Animals; Anopheles - genetics - parasitology - physiology; Culicidae - growth & development; Databases, Nucleic Acid; Ecosystem; Entomology; Female; Geography; Humans; Insect Vectors - genetics - parasitology - physiology; Italy; Longitudinal Studies; Malaria - parasitology - transmission; Polymerase Chain Reaction - veterinary; Population Density

Abstract: Europe was officially declared free from malaria in 1975; nevertheless, this disease remains a potential problem related to the presence of former vectors, belonging to the Anopheles maculipennis complex. Autochthonous-introduced malaria cases, recently reported in European countries, together with the predicted climatic and environmental changes, have increased the concern of health authorities over the possible resurgence of this disease in the Mediterranean Basin. In Italy, to study the distribution and bionomics of indigenous anopheline populations and to assess environmental parameters that could influence their dynamics, an entomological study was carried out in 2005-2006 in an at-risk study area. This model area is represented by the geographical region named the Maremma, a Tyrrhenian costal plain in Central Italy, where malaria was hyperendemic up to the 1950s. Fortnightly, entomological surveys (April-October) were carried out in four selected sites with different ecological features. Morphological and molecular characterization, blood meal identification, and parity rate assessment of the anophelines were performed. In total, 8274 mosquitoes were collected, 7691 of which were anophelines. Six Anopheles species were recorded, the most abundant of which were Anopheles labranchiae and An. maculipennis s.s. An. labranchiae is predominant in the coastal plain, where it is present in scattered foci. However, this species exhibits a wider than expected range: in fact it has been recorded, for the first time, inland where An. maculipennis s.s. is the most abundant species. Both species fed on a wide range of animal hosts, also showing a marked aggressiveness on humans, when available. Our findings demonstrated the high receptivity of the Maremma area, where the former malaria vector, An. labranchiae, occurs at different densities related to the kind of environment, climatic parameters, and anthropic activities.

PubMed ID: 19485768 View in PubMed

5th Western Alaska Interdisciplinary Science Conference and Forum (2012) : "Resilience in a changing world". [Abstract book]

https://arctichealth.org/en/permalink/ahliterature297025

Source: Western Alaska Interdisciplinary Science Conference Forum 2012. UAF Bristol Bay Campus, Dillingham, Alaska, March 28-31, 2012. 50 p.

Publication Type: Conference/Meeting Material

Date: 2012

, deschind@uw.edu The value of ecological complexity for maintaining the integrity and resilience of ecosystems Dr. Schindler is the Harriet Bullitt Chair of Conservation in the School of Aquatic and Fishery Sciences at the University of Washington. He earned a B.Sc. with Honors in Biology

1 document

Source: Western Alaska Interdisciplinary Science Conference Forum 2012. UAF Bristol Bay Campus, Dillingham, Alaska, March 28-31, 2012. 50 p.

Date: 2012

Language: English

Geographic Location: U.S.

Publication Type: Conference/Meeting Material

File Size: 3624398

Keywords: Alaska; Fisheries; Marine science; Traditional knowledge; Subsistence; Sustainable energy; Waste disposal; Food security; Ecosystems; Education

Documents

abstract-book.pdf

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30 years of data reveal dramatic increase in abundance of brown trout following the removal of a small hydrodam.

https://arctichealth.org/en/permalink/ahliterature292608

Source: J Environ Manage. 2017 Dec 15; 204(Pt 1):467-471

Publication Type: Journal Article

Date: Dec-15-2017

Author: Kim Birnie-Gauvin; Martin H Larsen; Jan Nielsen; Kim Aarestrup

Author Affiliation: DTU Aqua, Section for Freshwater Fisheries and Ecology, Vejlsøvej 39, 8600 Silkeborg, Denmark. Electronic address: kbir@aqua.dtu.dk.

Source: J Environ Manage. 2017 Dec 15; 204(Pt 1):467-471

Date: Dec-15-2017

Language: English

Publication Type: Journal Article

Keywords: Animals; Conservation of Natural Resources - methods; Denmark; Ecosystem; Rivers; Trout; Water Movements

Abstract: Humans and freshwater ecosystems have a long history of cohabitation. Today, nearly all major rivers of the world have an in-stream structure which changes water flow, substrate composition, vegetation, and fish assemblage composition. The realization of these effects and their subsequent impacts on population sustainability and conservation has led to a collective effort aimed to find ways to mitigate these impacts. Barrier removal has recently received greater interest as a potential solution to restore river connectivity, and reestablish high quality habitats, suitable for feeding, refuge and spawning of fish. In the present study, we present thirty years of data from electrofishing surveys obtained at two sites, both prior to and following the removal of a small-scale hydropower dam in Central Jutland, Denmark. We demonstrate that the dam removal has led to a dramatic increase in trout density, especially in young of the year. Surprisingly, we found that this increase was not just upstream of the barrier, where the ponded zone previously was, but also downstream of the barrier, despite little changes in habitat in that area. These findings suggest that barrier removal may be the soundest conservation option to reinstate fish population productivity.

PubMed ID: 28923580 View in PubMed

A 700-year paleoecological record of boreal ecosystem responses to climatic variation from Alaska.

https://arctichealth.org/en/permalink/ahliterature85780

Source: Ecology. 2008 Mar;89(3):729-43

Publication Type: Article

Date: Mar-2008

Author: Tinner Willy; Bigler Christian; Gedye Sharon; Gregory-Eaves Irene; Jones Richard T; Kaltenrieder Petra; KrÃ¤henbÃ¼hl Urs; Hu Feng Sheng

Author Affiliation: Institute of Plant Sciences and Oeschger Center for Climate Change Research, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland. willy.tinner@ips.unibe.ch

Source: Ecology. 2008 Mar;89(3):729-43

Date: Mar-2008

Language: English

Publication Type: Article

Keywords: Alaska; Climate; Diatoms; Ecosystem; Fires; Forestry; Fossils; Geologic sediments; Greenhouse Effect; Ice Cover; Plant Physiology; Pollen; Time Factors; Trees

Abstract: Recent observations and model simulations have highlighted the sensitivity of the forest-tundra ecotone to climatic forcing. In contrast, paleoecological studies have not provided evidence of tree-line fluctuations in response to Holocene climatic changes in Alaska, suggesting that the forest-tundra boundary in certain areas may be relatively stable at multicentennial to millennial time scales. We conducted a multiproxy study of sediment cores from an Alaskan lake near the altitudinal limits of key boreal-forest species. Paleoecological data were compared with independent climatic reconstructions to assess ecosystem responses of the forest tundra boundary to Little Ice Age (LIA) climatic fluctuations. Pollen, diatom, charcoal, macrofossil, and magnetic analyses provide the first continuous record of vegetation fire-climate interactions at decadal to centennial time scales during the past 700 years from southern Alaska. Boreal-forest diebacks characterized by declines of Picea mariana, P. glauca, and tree Betula occurred during the LIA (AD 1500-1800), whereas shrubs (Alnus viridis, Betula glandulosa/nana) and herbaceous taxa (Epilobium, Aconitum) expanded. Marked increases in charcoal abundance and changes in magnetic properties suggest increases in fire importance and soil erosion during the same period. In addition, the conspicuous reduction or disappearance of certain aquatic (e.g., Isoetes, Nuphar, Pediastrum) and wetland (Sphagnum) plants and major shifts in diatom assemblages suggest pronounced lake-level fluctuations and rapid ecosystem reorganization in response to LIA climatic deterioration. Our results imply that temperature shifts of 1-2 degrees C, when accompanied by major changes in moisture balance, can greatly alter high-altitudinal terrestrial, wetland, and aquatic ecosystems, including conversion between boreal-forest tree line and tundra. The climatic and ecosystem variations in our study area appear to be coherent with changes in solar irradiance, suggesting that changes in solar activity contributed to the environmental instability of the past 700 years.

PubMed ID: 18459336 View in PubMed

4200 years of pine-dominated upland forest dynamics in west-central Mexico: human or natural legacy?

https://arctichealth.org/en/permalink/ahliterature155658

Source: Ecology. 2008 Jul;89(7):1893-907

Publication Type: Article

Date: Jul-2008

Author: Blanca L Figueroa-Rangel; Katherine J Willis; Miguel Olvera-Vargas

Author Affiliation: Oxford Long-term Ecology Laboratory, Oxford University Centre for the Environment, School of Geography, South Parks Road, Oxford, OX1 3QY, United Kingdom. bfrangel@cucsur.udg.mx

Source: Ecology. 2008 Jul;89(7):1893-907

Date: Jul-2008

Language: English

Publication Type: Article

Keywords: Climate; Ecosystem; Fossils; Human Activities; Humans; Mexico; Paleontology; Pinus - physiology; Pollen; Population Dynamics; Soil; Time Factors; Trees - physiology

Abstract: The pine-dominated forests of west-central Mexico are internationally recognized for their high biodiversity, and some areas are protected through various conservation measures including prohibition of human activity. In this region, however, there is evidence for human settlement dating back to ca. AD 1200. It is therefore unclear whether the present forest composition and structure are part of a successional stage following use by indigenous human populations during the past, or due to natural processes, such as climate. We present a study reconstructing the vegetation dynamics of pine-dominated forest over the past 4200 years using paleoecological techniques. Results from fossil pollen and charcoal indicate that, in this region, pine-dominated forests are the native vegetation type and not anthropogenically derived secondary succession. The predominant driving mechanism for the expansion of pine-dominated forest appears to be intervals of aridity and naturally induced burning. A close association is noted between pine abundance and longer-term climatic trends, including intervals of aridity between ca. 4200 and 2500, 1200 and 850, and 500 and 200 cal yr BP and shorter-term trends. Evident periodicity occurs in pine and Poaceae abundance every 80 years. These short-term quasi-periodic oscillations have been recorded in a number of lake and ocean sediments in Mexico and are thought to be linked to solar forcing resulting in drought cycles that occur at approximately the same time intervals.

PubMed ID: 18705376 View in PubMed

Aboriginal hunting buffers climate-driven fire-size variability in Australia's spinifex grasslands.

https://arctichealth.org/en/permalink/ahliterature123525

Source: Proc Natl Acad Sci U S A. 2012 Jun 26;109(26):10287-92

Publication Type: Article

Date: Jun-26-2012

Author: Rebecca Bliege Bird; Brian F Codding; Peter G Kauhanen; Douglas W Bird

Author Affiliation: Department of Anthropology, Stanford University, Stanford, CA 94305, USA. rbird@stanford.edu

Source: Proc Natl Acad Sci U S A. 2012 Jun 26;109(26):10287-92

Date: Jun-26-2012

Language: English

Publication Type: Article

Keywords: Climate; Ecosystem; Humans; Oceanic Ancestry Group; Poaceae

Abstract: Across diverse ecosystems, greater climatic variability tends to increase wildfire size, particularly in Australia, where alternating wet-dry cycles increase vegetation growth, only to leave a dry overgrown landscape highly susceptible to fire spread. Aboriginal Australian hunting fires have been hypothesized to buffer such variability, mitigating mortality on small-mammal populations, which have suffered declines and extinctions in the arid zone coincident with Aboriginal depopulation. We test the hypothesis that the relationship between climate and fire size is buffered through the maintenance of an anthropogenic, fine-grained fire regime by comparing the effect of climatic variability on landscapes dominated by Martu Aboriginal hunting fires with those dominated by lightning fires. We show that Aboriginal fires are smaller, more tightly clustered, and remain small even when climate variation causes huge fires in the lightning region. As these effects likely benefit threatened small-mammal species, Aboriginal hunters should be considered trophic facilitators, and policies aimed at reducing the risk of large fires should promote land-management strategies consistent with Aboriginal burning regimes.

Notes: Cites: Proc Biol Sci. 2007 Feb 7;274(1608):341-617164197; Cites: Conserv Biol. 2006 Dec;20(6):1610-917181796; Cites: Proc Natl Acad Sci U S A. 2008 Sep 30;105(39):14796-80118809925; Cites: Biol Rev Camb Philos Soc. 2010 Aug;85(3):501-2120015313; Cites: Proc Biol Sci. 2009 Sep 22;276(1671):3249-5619535372; Cites: Science. 2009 Nov 20;326(5956):1100-319965426; Cites: Science. 2009 Apr 24;324(5926):481-419390038

PubMed ID: 22689979 View in PubMed

Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

https://arctichealth.org/en/permalink/ahliterature104173

Source: Ecology. 2014 Apr;95(4):963-77

Publication Type: Article

Date: Apr-2014

Author: Grégoire T Freschet; Lars Ostlund; Emilie Kichenin; David A Wardle

Source: Ecology. 2014 Apr;95(4):963-77

Date: Apr-2014

Language: English

Publication Type: Article

Keywords: Arctic Regions; Ecosystem; Environment; Environmental monitoring; Human Activities; Humans; Population Groups; Soil; Sweden; Time Factors; Trees - physiology

Abstract: Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after 100 years, their low-intensity but long-term land use at settlement sites has triggered a rejuvenation of the ecosystem that is still present. Our data demonstrates that aboveground-belowground interactions strongly control ecosystem responses to historical human land use and that medium- to long-term consequences of even low-intensity human activities must be better accounted for if we are to predict and manage ecosystems succession following land-use abandonment.

PubMed ID: 24933815 View in PubMed

Abrupt changes in the composition and function of fungal communities along an environmental gradient in the high Arctic.

https://arctichealth.org/en/permalink/ahliterature289464

Source: Mol Ecol. 2017 Sep; 26(18):4798-4810

Publication Type: Journal Article

Date: Sep-2017

Author: Oriol Grau; József Geml; Aaron Pérez-Haase; Josep M Ninot; Tatiana A Semenova-Nelsen; Josep Peñuelas

Author Affiliation: CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Cerdanyola del Vallès, Catalonia, Spain.

Source: Mol Ecol. 2017 Sep; 26(18):4798-4810

Date: Sep-2017

Language: English

Publication Type: Journal Article

Keywords: Arctic Regions; DNA Barcoding, Taxonomic; DNA, Fungal - genetics; Ecosystem; Fungi - classification; Greenland; Mycobiome; Sequence Analysis, DNA; Soil Microbiology

Abstract: Fungi play a key role in soil-plant interactions, nutrient cycling and carbon flow and are essential for the functioning of arctic terrestrial ecosystems. Some studies have shown that the composition of fungal communities is highly sensitive to variations in environmental conditions, but little is known about how the conditions control the role of fungal communities (i.e., their ecosystem function). We used DNA metabarcoding to compare taxonomic and functional composition of fungal communities along a gradient of environmental severity in Northeast Greenland. We analysed soil samples from fell fields, heaths and snowbeds, three habitats with very contrasting abiotic conditions. We also assessed within-habitat differences by comparing three widespread microhabitats (patches with high cover of Dryas, Salix, or bare soil). The data suggest that, along the sampled mesotopographic gradient, the greatest differences in both fungal richness and community composition are observed amongst habitats, while the effect of microhabitat is weaker, although still significant. Furthermore, we found that richness and community composition of fungi are shaped primarily by abiotic factors and to a lesser, though still significant extent, by floristic composition. Along this mesotopographic gradient, environmental severity is strongly correlated with richness in all fungal functional groups: positively in saprotrophic, pathogenic and lichenised fungi, and negatively in ectomycorrhizal and root endophytic fungi. Our results suggest complex interactions amongst functional groups, possibly due to nutrient limitation or competitive exclusion, with potential implications on soil carbon stocks. These findings are important in the light of the environmental changes predicted for the Arctic.

PubMed ID: 28664999 View in PubMed

Abrupt changes in the composition and function of fungal communities along an environmental gradient in the high Arctic.

https://arctichealth.org/en/permalink/ahliterature289622

Source: Mol Ecol. 2017 Sep; 26(18):4798-4810

Publication Type: Journal Article

Date: Sep-2017

Author: Oriol Grau; József Geml; Aaron Pérez-Haase; Josep M Ninot; Tatiana A Semenova-Nelsen; Josep Peñuelas

Author Affiliation: CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Cerdanyola del Vallès, Catalonia, Spain.

Source: Mol Ecol. 2017 Sep; 26(18):4798-4810

Date: Sep-2017

Language: English

Publication Type: Journal Article

Keywords: Arctic Regions; DNA Barcoding, Taxonomic; DNA, Fungal - genetics; Ecosystem; Fungi - classification; Greenland; Mycobiome; Sequence Analysis, DNA; Soil Microbiology

Abstract: Fungi play a key role in soil-plant interactions, nutrient cycling and carbon flow and are essential for the functioning of arctic terrestrial ecosystems. Some studies have shown that the composition of fungal communities is highly sensitive to variations in environmental conditions, but little is known about how the conditions control the role of fungal communities (i.e., their ecosystem function). We used DNA metabarcoding to compare taxonomic and functional composition of fungal communities along a gradient of environmental severity in Northeast Greenland. We analysed soil samples from fell fields, heaths and snowbeds, three habitats with very contrasting abiotic conditions. We also assessed within-habitat differences by comparing three widespread microhabitats (patches with high cover of Dryas, Salix, or bare soil). The data suggest that, along the sampled mesotopographic gradient, the greatest differences in both fungal richness and community composition are observed amongst habitats, while the effect of microhabitat is weaker, although still significant. Furthermore, we found that richness and community composition of fungi are shaped primarily by abiotic factors and to a lesser, though still significant extent, by floristic composition. Along this mesotopographic gradient, environmental severity is strongly correlated with richness in all fungal functional groups: positively in saprotrophic, pathogenic and lichenised fungi, and negatively in ectomycorrhizal and root endophytic fungi. Our results suggest complex interactions amongst functional groups, possibly due to nutrient limitation or competitive exclusion, with potential implications on soil carbon stocks. These findings are important in the light of the environmental changes predicted for the Arctic.

PubMed ID: 28664999 View in PubMed

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2nd Norwegian Environmental Toxicology Symposium: joining forces for an integrated search for environmental solutions.

https://arctichealth.org/en/permalink/ahliterature90204

A 2-year entomological study of potential malaria vectors in central Italy.

https://arctichealth.org/en/permalink/ahliterature150651

5th Western Alaska Interdisciplinary Science Conference and Forum (2012) : "Resilience in a changing world". [Abstract book]

https://arctichealth.org/en/permalink/ahliterature297025

Documents

30 years of data reveal dramatic increase in abundance of brown trout following the removal of a small hydrodam.

https://arctichealth.org/en/permalink/ahliterature292608

A 700-year paleoecological record of boreal ecosystem responses to climatic variation from Alaska.

https://arctichealth.org/en/permalink/ahliterature85780

4200 years of pine-dominated upland forest dynamics in west-central Mexico: human or natural legacy?

https://arctichealth.org/en/permalink/ahliterature155658

Aboriginal hunting buffers climate-driven fire-size variability in Australia's spinifex grasslands.

https://arctichealth.org/en/permalink/ahliterature123525

Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

https://arctichealth.org/en/permalink/ahliterature104173

Abrupt changes in the composition and function of fungal communities along an environmental gradient in the high Arctic.

https://arctichealth.org/en/permalink/ahliterature289464

Abrupt changes in the composition and function of fungal communities along an environmental gradient in the high Arctic.

https://arctichealth.org/en/permalink/ahliterature289622