34 research outputs found
Canvis en la superficie i el grau de fragmentació del bosc a la plana del Vallès entre els anys 1993 i 2000
En aquest article s’hi analitzen la variació en la superfície de bosc, el grau de fragmentació, les cobertes d’origen del bosc guanyat i la mida i la forma dels polígons de bosc perduts i guanyats a la plana del Vallès entre 1993 i 2000, combinant les dues edicions del mapa de cobertes del sòl de Catalunya (MCSC) amb el SIG MiraMon. La disminució del bosc dens no de ribera en aquesta zona ha estat gairebé del 3% en el període d’estudi. El bosc perdut ha esdevingut majoritàriament superfície forestal no arbrada (matollars i prats), urbana i agrícola. També hi ha hagut una certa recuperació de bosc, que no compensa les pèrdues i que prové principalment de cobertes forestals no arbrades i de conreus. S’observa també un increment de la fragmentació del bosc, que ha afectat a més del 10% de la superfície de les grans àrees boscoses. S’hi comenten finalment la validesa del mètode i les implicacions ecològiques i de conservació d’aquests resultats.Changes in forest area, forest fragmentation, the land cover classes of origin of the gained forest and of destiny of the lost forest, and size and form of the gained and lost forest patches were evaluated in the Vallès lowlands (Barcelona Metropolitan Area) between 1993 and 2000, by combining the two editions of the land cover map of Catalonia (MCSC) using the MiraMon SIG. The area occupied by dense, non-riparian forest decreased by 3% in the studied period. The lost forest has been substituted by shrublands-grasslands, urban land, and croplands. There has been a small recovery of forest as well, mainly from shrublands- grasslands and croplands, which does not compensate the forest loss. An increase of forest fragmentation has also been observed, affecting more than 10% of the surface of the large forest areas. The validity of the methodology and the ecological implications of these results for conservation are finally addressed.En el presente artículo se analizan la variación en la superficie de bosque, su fragmentación, las cubiertas de origen del bosque ganado y de destino del bosque perdido y el tamaño y la forma de los polígonos de bosque perdidos y ganados en el llano del Vallès (área metropolitana de Barcelona) entre 1993 y 2000, combinando las dos ediciones del mapa de cubiertas del suelo de Cataluña (MCSC) con el SIG MiraMon. La disminución del bosque denso no de ribera en esta zona ha sido de casi el 3% en el periodo estudiado. El bosque perdido ha pasado a ser mayoritariamente superficie forestal no arbolada (matorrales y prados), urbana y agrícola. También ha habido una cierta recuperación de bosque que no compensa las pérdidas y que proviene principalmente de cubiertas forestales no arboladas y de cultivos. Se observa también un incremento de la fragmentación del bosque en la zona de estudio, que ha afectado a más del 10% de la superficie de las grandes áreas forestales. Se comentan, finalmente, la validez del método y las implicaciones ecológicas y de conservación de estos resultados
Land use changes, landscape ecology and their socioeconomic driving forces in the Spanish Mediterranean coast (the Maresme County, 1850-2005)
We use a set of landscape metrics to study the long-term environmental transformation of a typical coastal Mediterranean area from 1850 to 2005. Our figures show a dramatic environmental deterioration between 1950 and 2005. The main proximate drivers of this landscape degradation are the effects of urban sprawl on former agricultural areas located in the coastal plains, together with the abandonment and reforestation of hilly slopes intercepted by low-density residential areas, highways, and other linear infrastructures. We carry out a statistical redundancy analysis (RDA) to identify certain ultimate socioeconomic and political drivers of these environmental impacts. The results confirm our interpretive hypothesis that: 1) land cover changes determine changes in landscape properties, both structural and functional; 2) these changes are not at random, but related to geographical endowments and socioeconomic or political drivers.statistical redundancy analysis (rda), ecological connectivity, land-use change, socioeconomic drivers, mediterranean landscapes
Canvis en la superficie i el grau de fragmentació del bosc a la plana del Vallès entre els anys 1993 i 2000
En aquest article s'hi analitzen la variació en la superfície de bosc, el grau de fragmentació, les cobertes d'origen del bosc guanyat i la mida i la forma dels polígons de bosc perduts i guanyats a la plana del Vallès entre 1993 i 2000, combinant les dues edicions del mapa de cobertes del sòl de Catalunya (MCSC) amb el SIG MiraMon. La disminució del bosc dens no de ribera en aquesta zona ha estat gairebé del 3% en el període d'estudi. El bosc perdut ha esdevingut majoritàriament superfície forestal no arbrada (matollars i prats), urbana i agrícola. També hi ha hagut una certa recuperació de bosc, que no compensa les pèrdues i que prové principalment de cobertes forestals no arbrades i de conreus. S'observa també un increment de la fragmentació del bosc, que ha afectat a més del 10% de la superfície de les grans àrees boscoses. S'hi comenten finalment la validesa del mètode i les implicacions ecològiques i de conservació d'aquests resultats.En el presente artículo se analizan la variación en la superficie de bosque, su fragmentación, las cubiertas de origen del bosque ganado y de destino del bosque perdido y el tamaño y la forma de los polígonos de bosque perdidos y ganados en el llano del Vallès (área metropolitana de Barcelona) entre 1993 y 2000, combinando las dos ediciones del mapa de cubiertas del suelo de Cataluña (MCSC) con el SIG MiraMon. La disminución del bosque denso no de ribera en esta zona ha sido de casi el 3% en el periodo estudiado. El bosque perdido ha pasado a ser mayoritariamente superficie forestal no arbolada (matorrales y prados), urbana y agrícola. También ha habido una cierta recuperación de bosque que no compensa las pérdidas y que proviene principalmente de cubiertas forestales no arboladas y de cultivos. Se observa también un incremento de la fragmentación del bosque en la zona de estudio, que ha afectado a más del 10% de la superficie de las grandes áreas forestales. Se comentan, finalmente, la validez del método y las implicaciones ecológicas y de conservación de estos resultados.Les changements de la surface de forêt, la fragmentation, les couvertures d'origine de la forêt gagné et du destin de la forêt perdue, et la taille et forme des taches gagnées et perdues de forêt entre 1993 et 2000 ont été évalués a la plaine du Vallès (aire métropolitaine de Barcelone), en combinant les deux éditions de la carte de couverture du sol de la Catalogne (MCSC) avec le SIG MiraMon. La fôret dense non de galerie est réduite d'un 3% à l'aire d'étude. Il y a eu un petit rétablissement de forêt qui n'a pas compensé les pertes et qui viens principalement des fourrés-pelouses et des cultures. On a également observé une augmentation de fragmentation de la forêt, affectant plus de 10% de la surface des grandes aires forestières. On commente finalement l'utilité de la méthodologie et les implications écologiques de ces résultats pour la conservation.Changes in forest area, forest fragmentation, the land cover classes of origin of the gained forest and of destiny of the lost forest, and size and form of the gained and lost forest patches were evaluated in the Vallès lowlands (Barcelona Metropolitan Area) between 1993 and 2000, by combining the two editions of the land cover map of Catalonia (MCSC) using the MiraMon SIG. The area occupied by dense, non-riparian forest decreased by 3% in the studied period. The lost forest has been substituted by shrublands-grasslands, urban land, and croplands. There has been a small recovery of forest as well, mainly from shrublands- grasslands and croplands, which does not compensate the forest loss. An increase of forest fragmentation has also been observed, affecting more than 10% of the surface of the large forest areas. The validity of the methodology and the ecological implications of these results for conservation are finally addressed
Ecosystem services provided by green infrastructure in the urban environment
Interest in ecosystems services and green infrastructures is a result of conceptual developments in urban ecology and other environmental sciences. The impact of the urban settlements on nature and its consequences on human well-being at multi-scale levels demands for technical and social responses, whose application has been revealed to be highly dependent on the physical and socio-economic context. We review here problems and efforts to create a solid conceptual framework and efficient tools to analyse and manage urban social-ecosystems in order to increase the benefits that green infrastructure gives to the entire society, giving resilience to these systems. Difficulties become even greater as a result of weak institutional structures, limited capacity and poor governance strategies
Social perception of ecosystem services in a coastal wetland post-earthquake : a case study in Chile
Natural disasters can cause abrupt disturbances in coastal wetlands, affecting the social perception of ecosystem services (ES). The Tubul-Raqui coastal wetland is one of the most important wetlands in south-central Chile. Rich in biodiversity, these wetlands provide ES to a population of 2238 inhabitants. The recent M = 8.8 earthquake of 2010 caused a coastal uplift of 1.4 m and substantial morphological, social, and environmental changes. This paper analyzes the social perceptions of the inhabitants of the village of Tubul-Raqui following a large earthquake disturbance with regards to ES provision frequency and their future changes. A statistically representative semi-structured survey was conducted (175 valid surveys) and the data interpreted through factor analysis and statistical tests for independent categorical variables. The perception of cultural and regulating services was significantly greater than that of provisioning services, which were probably the most affected by the earthquake. Residents identified habitat for species, recreation, and hazard regulation as the most important ES. Perception was influenced by the categorical variables of gender, age, and ethnicity; for example, hazard regulation services varied strongly by gender. According to the respondents, the availability of ES will remain stable (50%) or decrease (40%) in the next 50 years, mainly due to anthropogenic drivers; the effect of natural disasters was not mentioned among the main drivers of change
Satellite data as indicators of tree biomass growth and forest dieback in a Mediterranean holm oak forest
Context : In the framework of climate change, decreased tree growth and enhanced mortality induced by hot and dry conditions are increasing in many forests around the world, and particularly in Mediterranean forests.- Aims : Our aim was to estimate tree growth and mortality in a Mediterranean holm oak forest, using remote sensing data from MODIS. - Methods: We monitored annual increases of aboveground biomass by measuring tree basal area, and we determined tree mortality by counting dead stems. We analyzed the relationships between forest growth and mortality with mean annual values of some MODIS products and meteorological data. - Results: Mortality and increases of aboveground biomass correlated well with precipitation, September standardized precipitation/evapotranspiration indices (SPEI), and some MODIS products such as NDVI and enhanced vegetation index EVI. Other MODIS products such as gross primary production (GPP) and net photosynthesis, however, showed no clear relationship with tree mortality or measured increases of biomass. - Conclusion: The MODIS products as proxies of ecosystemic productivity (gross primary productivity, net photosynthesis) were weakly correlated with biomass increase, and did not reflect the mortality following the drought of autumn 2011. Nevertheless, NDVI and EVI were efficient indicators of forest productivity and diebac
Effects of past landscape and habitat changes in plant invasion provide evidence of an invasion credit
Habitats differ in the invasion degree due to habitat properties and current spatial context. Historical context effects (i.e. land use change legacy) have been little studied and can be modulated by the invasion credit (the delayed increase in habitat invasion after changes in the land use). In this study we considered historical context to know if habitat changes affect the diverse components of plant invasion (introduction, establishment and spread) and to find evidence of invasion credit. The study is performed in the Barcelona province and consists in 531 sampling points distributed along 9 different habitats where we sampled the abundance (cover percentage) of each recorded alien plant species. Habitat and current and historical (past landscape and changes) spatial context variables were used to create the best model explaining introduction and establishment (presence and richness) and spread (mean abundance) of alien species in sampling points. The results show that alien species presence and richness are mostly influenced by habitat and topography but also by the number of changes, which suggests an effect of the land use legacy. The relationship between the historical landscape and alien species abundance provides evidence of an invasion credit. In conclusion, we have found evidence of an invasion credit in the spread stage while there is an effect of the historical legacy in the introduction and establishment. However, habitat invasion is a complex process affected by several factors such as species traits, the introduction event and residence time that should be considered in further studies
Learning and the transformative potential of citizen science
The number of collaborative initiatives between scientists and volunteers (i.e., citizen science) is increasing across many research fields. The promise of societal transformation together with scientific breakthroughs contributes to the current popularity of citizen science (CS) in the policy domain. We examined the transformative capacity of citizen science in particular learning through environmental CS as conservation tool. We reviewed the CS and social-learning literature and examined 14 conservation projects across Europe that involved collaborative CS. We also developed a template that can be used to explore learning arrangements (i.e., learning events and materials) in CS projects and to explain how the desired outcomes can be achieved through CS learning. We found that recent studies aiming to define CS for analytical purposes often fail to improve the conceptual clarity of CS; CS programs may have transformative potential, especially for the development of individual skills, but such transformation is not necessarily occurring at the organizational and institutional levels; empirical evidence on simple learning outcomes, but the assertion of transformative effects of CS learning is often based on assumptions rather than empirical observation; and it is unanimous that learning in CS is considered important, but in practice it often goes unreported or unevaluated. In conclusion, we point to the need for reliable and transparent measurement of transformative effects for democratization of knowledge production
Impacts of Use and Abuse of Nature in Catalonia with Proposals for Sustainable Management
This paper provides an overview of the last 40 years of use, and in many cases abuse, of the natural resources in Catalonia, a country that is representative of European countries in general, and especially those in the Mediterranean region. It analyses the use of natural resources made by mining, agriculture, livestock, logging, fishing, nature tourism, and energy production and consumption. This use results in an ecological footprint, i.e., the productive land and sea surface required to generate the consumed resources and absorb the resulting waste, which is about seven times the amount available, a very high number but very similar to other European countries. This overexploitation of natural resources has a huge impact on land and its different forms of cover, air, and water. For the last 25 years, forests and urban areas have each gained almost 3% more of the territory at the expense of agricultural land; those municipalities bordering the sea have increased their number of inhabitants and activity, and although they only occupy 6.7% of the total surface area, they account for 43.3% of the population; air quality has stabilized since the turn of the century, and there has been some improvement in the state of aquatic ecosystems, but still only 36% are in good condition, while the remainder have suffered morphological changes and different forms of nonpoint source pollution; meanwhile the biodiversity of flora and fauna remains still under threat. Environmental policies do not go far enough so there is a need for revision of the legislation related to environmental impact and the protection of natural areas, flora, and fauna. The promotion of environmental research must be accompanied by environmental education to foster a society which is more knowledgeable, has more control and influence over the decisions that deeply affect it. Indeed, nature conservation goes hand in hand with other social and economic challenges that require a more sustainable vision. Today's problems with nature derive from the current economic model, which is environmentally unsustainable in that it does not take into account environmental impacts. Lastly, we propose a series of reasonable and feasible priority measures and actions related to each use made of the country's natural resources, to the impacts they have had, and to their management, in the hope that these can contribute to improving the conservation and management of the environment and biodiversity and move towards sustainability