Traditional ecological knowledge and community resilience to environmental extremes: A case study in Doñana,SW Spain     

Erik Gómez-Baggethun  Victoria Reyes-García  Per Olsson  Carlos Montes 《Global Environmental Change》2012,22(3):640-650

Research in the last decade has emphasised the potential contribution of traditional ecological knowledge to cope with challenges from global environmental change. This research examines the role of traditional ecological knowledge and shared systems of beliefs in building long-term social–ecological resilience to environmental extremes. Data were collected from 13 villages of the Doñana region, southwestern Spain, through interviews, focus groups, and systematic reviews of historical archives. First, we assess adaptive practices to cope with environmental change. Then, we use historical records of religious ceremonies (1577–1956) to reconstruct collective responses to environmental extremes. Our results (1) show how environmental extremes could induce social and economic crises through declines in ecosystem services and (2) identify practices to cope with recurrent disturbance and institutional devices developed in response to environmental extremes. We conclude that traditional ecological knowledge and shared systems of beliefs can facilitate collective responses to crises and contribute to the maintenance of long-term resilience of social–ecological systems.  相似文献   

Road investment as enabling local economic development? Evidence from a rural Philippine fishing village     

Jerry Olsson 《Singapore journal of tropical geography》2010,31(3):343-356

This paper investigates how efforts to achieve local economic growth conflicted with long‐term sustainable resource use when road accessibility was improved between a supply area – the households and household firms in a Philippine fishing village, Dinahican, previously hampered by very poor transport conditions and accessibility – and its major market. Findings indicate that improved road access to big fish markets stimulated investment in production enhancing inputs, which allowed increased fish landings and sales outside Dinahican, together with employment and incomes. At the same time, poorly implemented fisheries resource management resulted in overfishing in municipal waters and obvious disparities in access to productive resources. Thus, while road investment in relatively inaccessible rural resource rich areas may spur economic development as an underutilized production potential is released, it can facilitate resource depletion and intensify an unequal distribution of benefits if the enforcement of laws and regulations is lacking. In the case of Dinahican, coordination between infrastructure supply and the implementation and enforcement of fisheries resource management is found to be urgently needed.  相似文献   

Wetland development, permafrost history and nutrient cycling inferred from late Holocene peat and lake sediment records in subarctic Sweden     

Ulla Kokfelt  Nina Reuss  Eric Struyf  Mats Sonesson  Mats Rundgren  G?ran Skog  Peter Rosén  Dan Hammarlund 《Journal of Paleolimnology》2010,44(1):327-342

Permafrost in peatlands of subarctic Sweden is presently thawing at accelerated rates, which raises questions about the destiny of stored carbon and nutrients and impacts on adjacent freshwater ecosystems. In this study we use peat and lake sediment records from the Stordalen palsa mire in northern Sweden to address the late Holocene (5,000 cal BP-present) development of the mire as well as related changes in carbon and nutrient cycling. Formation, sediment accumulation and biogeochemistry of two studied lakes are suggested to be largely controlled by the development of the mire and its permafrost dynamics. Peat inception took place at ca. 4,700 cal BP as a result of terrestrialisation. Onset of organic sedimentation in the adjacent lakes occurred at ca. 3,400 and 2,650 cal BP in response to mire expansion and permafrost aggradation, respectively. Mire erosion, possibly due to permafrost decay, led to re-deposition of peat into one of the lakes after ca. 2,100 cal BP, and stimulated primary productivity in the other lake at ca. 1,900–1,800 cal BP. Carbonate precipitation appears to have been suppressed when acidic poor fen and bog (palsa) communities dominated the catchment mire, and permafrost-induced changes in hydrology may further have affected the inflow of alkaline water from the catchment. Elevated contents of biogenic silica and diatom pigments in lake sediments during periods of poor fen and bog expansion further indicate that terrestrial vegetation influenced the amount of nutrients entering the lake. Increased productivity in the lake likely caused bottom-water anoxia in the downstream lake and led to recycling of sediment phosphorous, bringing the lake into a state of self-sustained eutrophication during two centuries preceding the onset of twentieth century permafrost thaw. Our results give insight into nutrient and permafrost dynamics in a subarctic wetland and imply that continued permafrost decay and related vegetation changes towards minerotrophy may increase carbon and nutrient storage of mire deposits and reduce nutrient fluxes in runoff. Rapid permafrost degradation may on the other hand lead to widespread mire erosion and to relatively short periods of significantly increased nutrient loading in adjacent lakes.  相似文献   

Response of the North Atlantic subpolar gyre to persistent North Atlantic oscillation like forcing   总被引：2，自引：1，他引：1  

Katja Lohmann  Helge Drange  Mats Bentsen 《Climate Dynamics》2009,32(2-3):273-285

The response of the North Atlantic subpolar gyre (SPG) to a persistent positive (or negative) phase of the North Atlantic oscillation (NAO) is investigated using an ocean general circulation model forced with idealized atmospheric reanalysis fields. The integrations are analyzed with reference to a base-line integration for which the model is forced with idealized fields representing a neutral state of the NAO. In the positive NAO case, the results suggest that the well-known cooling and strengthening of the SPG are, after about 10 years, replaced by a warming and subsequent weakening of the SPG. The latter changes are caused by the advection of warm water from the subtropical gyre (STG) region, driven by a spin-up of the Atlantic meridional overturning circulation (AMOC) and the effect of an anomalous wind stress curl in the northeastern North Atlantic, which counteracts the local buoyancy forcing of the SPG. In the negative NAO case, however, the SPG response does not involve a sign reversal, but rather shows a gradual weakening throughout the integration. The asymmetric SPG-response to the sign of persistent NAO-like forcing and the different time scales involved demonstrate strong non-linearity in the North Atlantic Ocean circulation response to atmospheric forcing. The latter finding indicates that analysis based on the arithmetic difference between the two NAO-states, e.g. NAO+ minus NAO?, may hide important aspects of the ocean response to atmospheric forcing.  相似文献   

Commuters’ non-linear response to time distances   总被引：2，自引：0，他引：2  

B?rje?JohanssonEmail author  Johan?Klaesson  Michael?Olsson 《Journal of Geographical Systems》2003,5(3):315-329

Established analyses of labour market commuting are based on random choice models and gravity type models. In these models generalised transport costs are formulated as exponential or log-linear distance dependent functions. This paper presents empirical observations, which imply that time distances influence the commuting behaviour in a non-linear way, such that the time sensitivity is much lower for very short and long distances, whereas intermediate distances display a high time sensitivity. This is explained in a model that is parameterised and estimated. The results are important for understanding and predicting commuter behaviour. It also helps to delineate space, as in classical traditions, into local, intra-regional and extra-regional space.  相似文献   

A reassessment of the non-stoichiometry of fayalite     

Mats Hillert  Malin Selleby  Bo Sundman 《Physics and Chemistry of Minerals》1996,23(6):387-390

The thermogravimetric measurements on fayalite reported by Nakamura and Schmalzried (1983) have been reassessed using the compound-energy model and computer calculations which eliminate much mathematical manipulation and subjective choice. The calculated phase field for fayalite differs somewhat from the one obtained by Nakamura and Schmalzried (1983) but there is satisfactory agreement in the experimental range.  相似文献   

An objective test of earthquake migrations in Turkey     

Rune Olsson 《Tectonophysics》1985,116(3-4)

An objective method for the examination of supposed migration of earthquake epicenters is discussed and tested for the Turkey region.  相似文献   

Tomographic inversion of P410s delay times for simultaneous determination of P and S velocities of the upper mantle beneath the Baltic Shield     

Sverker Olsson  Roland G. Roberts  R. Böðvarsson 《Physics of the Earth and Planetary Interiors》2007,160(2):157-168

Teleseismic data recorded by stations in the Swedish National Seismic Network (SNSN) are used for a study of upper mantle structure beneath the Baltic Shield using the receiver function technique. The data show very clear conversions from the 410 and 660 km discontinuities. The signals associated with P to S conversions at these discontinuities arrive 1-2 s earlier than predicted by global models such as IASP91 or PREM. We interpret this as a manifestation of higher than average velocities in the mantle beneath the shield, consistent with lower than average global temperatures. For a 1400 km profile along the network, we observe variations of around 1 second in delay times of P410s and slightly less for P660s. Under the assumption that the mantle discontinuities are at a given constant depth, the delay times of the mantle converted phases are tomographically inverted to reveal P and S velocity structure below the stations. Synthetic tests show that this tomographic inversion has the potential to resolve P and S velocity variations at structural scales adequate for upper mantle studies. Results from application to real data appear to be consistent with independently produced mantle velocity structures deduced from normal tomographic arrival time data. For the P velocity model, a north-dipping body of (relatively) low velocity is found for the central part of the profile at 58-64°N. A sharp contrast from low to high velocities that may be associated with the Proterozoic-Archean boundary is found at 66°N.  相似文献