36 resultados para natural protected areas
Resumo:
Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 14 marine protected areas and 18 open access sites across the Mediterranean, and across a 31-fold range of fish biomass (from 3.8 to 118 g m22). Our data showed remarkable variation in the structure of rocky reef ecosystems. Multivariate analysis showed three alternative community states: (1) large fish biomass and reefs dominated by non-canopy algae, (2) lower fish biomass but abundant native algal canopies and suspension feeders, and (3) low fish biomass and extensive barrens, with areas covered by turf algae. Our results suggest that the healthiest shallow rocky reef ecosystems in the Mediterranean have both large fish and algal biomass. Protection level and primary production were the only variables significantly correlated to community biomass structure. Fish biomass was significantly larger in well-enforced no-take marine reserves, but there were no significant differences between multi-use marine protected areas (which allow some fishing) and open access areas at the regional scale. The gradients reported here represent a trajectory of degradation that can be used to assess the health of any similar habitat in the Mediterranean, and to evaluate the efficacy of marine protected areas.
Resumo:
Catastrophic storms have been observed to be one of the major elements in shaping the standing structure of marine benthic ecosystems. Yet, little is known about the effect of catastrophic storms on ecosystem processes. Specifically, herbivory is the main control mechanism of macrophyte communities in the Mediterranean, with two main key herbivores: the sea urchin Paracentrotus lividus and the fish Sarpa salpa. Consequently, the effects of extreme storm events on these two herbivores (at the population level and on their behaviour) may be critical for the functioning of the ecosystem. With the aim of filling this gap, we took advantage of two parallel studies that were conducted before, during and after an unexpected catastrophic storm event. Specifically, fish and sea urchin abundance were assessed before and after the storm in monitored fixed areas (one site for sea urchin assessment and 3 sites for fish visual transects). Additionally, we investigated the behavioural response to the disturbance of S. salpa fishes that had been tagged with acoustic transmitters. Given their low mobility, sea urchins were severely affected by the storm (ca. 50% losses) with higher losses in those patches with a higher density of sea urchins. This may be due to a limited availability of refuges within each patch. In contrast, fish abundance was not affected, as fish were able to move to protected areas (i.e. deeper) as a result of the high mobility of this species. Our results highlight that catastrophic storms differentially affect the two dominant macroherbivores of rocky macroalgal and seagrass systems due to differences in mobility and escaping strategies. This study emphasises that under catastrophic disturbances, the presence of different responses among the key herbivores of the system may be critical for the maintenance of the herbivory function.
Resumo:
Seabirds are facing a growing number of threats in both terrestrial and marine habitats, and many populations have experienced dramatic changes over past decades. Years of seabird research have improved our understanding of seabird populations and provided a broader understanding of marine ecological processes. In an effort to encourage future research and guide seabird conservation science, seabird researchers from 9 nations identified the 20 highest priority research questions and organized these into 6 general categories: (1) population dynamics, (2) spatial ecology, (3) tropho-dynamics, (4) fisheries interactions, (5) response to global change, and (6) management of anthropogenic impacts (focusing on invasive species, contaminants and protected areas). For each category, we provide an assessment of the current approaches, challenges and future directions. While this is not an exhaustive list of all research needed to address the myriad conservation challenges seabirds face, the results of this effort represent an important synthesis of current expert opinion across sub-disciplines within seabird ecology. As this synthesis highlights, research, in conjunction with direct management, education, and community engagement, can play an important role in facilitating the conservation and management of seabird populations and of the ocean ecosystems on which they and we depend.
Resumo:
The integration of ecological and evolutionary data is highly valuable for conservation planning. However, it has been rarely used in the marine realm, where the adequate design of marine protected areas (MPAs) is urgently needed. Here, we examined the interacting processes underlying the patterns of genetic structure and demographic strucuture of a highly vulnerable Mediterranean habitat-forming species (i.e. Paramuricea clavata (Risso, 1826)), with particular emphasis on the processes of contemporary dispersal, genetic drift, and colonization of a new population. Isolation by distance and genetic discontinuities were found, and three genetic clusters were detected; each submitted to variations in the relative impact of drift and gene flow. No founder effect was found in the new population. The interplay of ecology and evolution revealed that drift is strongly impacting the smallest, most isolated populations, where partial mortality of individuals was highest. Moreover, the eco-evolutionary analyses entailed important conservation implications for P. clavata. Our study supports the inclusion of habitat-forming organisms in the design of MPAs and highlights the need to account for genetic drift in the development of MPAs. Moreover, it reinforces the importance of integrating genetic and demographic data in marine conservation.
Resumo:
En los últimos años, el uso turístico de las áreas protegidas ha aumentado considerablemente, y con él, el grado de impacto. Es por este motivo que se requieren medidas de gestión adecuadas para identificar, conocer y evaluar estos impactos potenciales y así poder actuar ofreciendo un uso recreativo de estas áreas a la vez que se asegura su conservación. El objetivo del presente trabajo fue establecer el grado de impacto que sufre la vegetaciòn y el suelo del Parque Nacional de Tierra del Fuego en las zonas de acampada y compararlas con las áreas adyacentes, como controles. Asimismo, se buscó establecer cuales son los indicadores de impacto de mayor relevancia para poder ser usados como herramientas de gestión. La evaluación se efectuó mediante el muestreo de 40 parcelas, transectas y intertransectas en donde se analizaron variables vegetacionales (cobertura arbórea, arbustiva y herbácea, porcentaje de suelo desnudo, daño en árboles y arbustos, y presencia de raíces expuestas) y del suelo (pH, materia orgánica, densidad aparente y humedad). El grado de impacto se estableció numéricamente con una fórmula matemática en donde se seleccionaron los parámetros evaluados y se corrigieron con factores de correción, dando un impacto clasificado como “compatible” en el área de Río Pipo y “moderado” en el área de Laguna Verde. También se formularon propuestas de manejo para prevenir y/o minimizar los impactos producidos en las zonas de camping.
Resumo:
Aquest estudi s’ha realitzat amb el principal objectiu de localitzar, analitzar i diagnosticar els arbres singulars subjectes a ser declarats monumentals dins el Parc Natural de l’Alt Pirineu. Concretament s’han inventariat la Vall Ferrera i la Vall de Cardós. L’objectiu secundari ha estat fer una proposta innovadora d’educació ambiental, utilitzant l’arbre com a un instrument pedagògic. S’han inventariat vint-i-tres arbres sent un d’ells ja declarat Arbre Monumental, “l’Avet del Pla de la Selva”. Primerament s’han localitzats els arbres amb l’ajuda dels tècnics del Parc, el coneixement popular i documentació. S’ha utilitzat una metodologia basada en estudis anteriors, mitjançant uns formularis de camp que recullen totes les característiques ecològiques i socioculturals de cada arbre. Posteriorment s’han analitzat les dades obtingudes i s’ha realitzat la diagnosi. S’ha proposat un mètode quantitatiu i un mètode qualitatiu (Rànquing d’Arbres Monumentals). Aquest últim valora cada arbre comparant-lo amb un llistat de tots aquells arbres monumentals de la mateixa espècie en el territori català realitzat per la Generalitat de Catalunya, segons tres paràmetres, l’alçada, el volt de canó i el diàmetre de la capçada. Finalment es proposa a cada arbre la protecció corresponent segons el seu estat de conservació i altres paràmetres. Un dels resultats obtinguts d’aquest estudi ha estat la realització d’una carpeta de material divulgatiu utilitzant cada arbre com a eix central per explicar el medi natural que l’envolta. Amb aquesta iniciativa es vol destacar l’important paper dels arbres monumentals com a connectors amb el medi natural i sociocultural i la necessitat de protegir en tots els Parcs Naturals els arbres singulars.
Resumo:
La intrusió de les plantes exòtiques invasores en els espais naturals protegits de Catalunya s’ha convertit en un problema de primer ordre. En alguns d’aquests espais fa temps que s’han començat a gestionar aquestes espècies exòtiques. No és el cas del PNAP, que degut a la seva recent creació, encara no ha pogut tractar a fons aquesta problemàtica. Per tant, amb el present estudi s’ha treballat en conèixer la distribució d’aquetes espècies en el Parc i en crear una base de referència. La major part de les plantes trobades estan situades en llocs on la pressió humana es molt forta. Un cop establertes prop de les àrees més antropitzades, aquestes espècies es disseminen pel territori aprofitant-se de les zones degradades per establir-se. Per aquesta raó, també es proposen les mesures d’actuació més adients per a gestionar aquestes espècies en el territori de l’Alt Pirineu, prenent com a referent les actuacions que es duen a terme avui arreu del món.
Resumo:
This research explores critical environmental concepts from the standpoint of political ecology. It contrasts the Ecuadorian Kichua indigenous concept of Sumak Kawsay (i.e., living well), with discourses about natural, urban and rural areas. Sumak Kawsay was included in Ecuador’s 2008 constitution as an alternative to the neoclassical idea of development. This work reveals interesting insights from a variety of social and political viewpoints from both rural and urban areas. The research is based on the medium sized city of Cuenca, which is located in the southern Ecuadorian Andes. We used an adaptation of the Q Method to investigate stakeholders’ perceptions. Four remarkably well-defined viewpoints were revealed. Although these views contrast strongly with Sumak Kawsay, it is possible to transform this paradigm in the foundation of Cuenca’s public policies and institutional structure.
Resumo:
L’anàlisi de l’estat actual dels equipaments i activitats d’educació ambiental (EA) en l’àmbit del Parc Natural de l’Alt Pirineu (PNAP) ha detectat un grau de desenvolupament molt baix d’aquesta disciplina. Per aquest motiu, s’elabora una nova eina, amb l’objectiu d’establir unes pautes per a l’elaboració d’una activitat d’EA concreta: els itineraris d’EA; i així ampliar l’escassa oferta actual. El protocol per al disseny d’itineraris d’EA, dóna unes directrius per a estandarditzar la descripció i l’anàlisi de la zona proposada. La finalitat del qual és facilitar i agilitar la implantació d’itineraris que presentin unes condicions mínimes establertes. La eficiència d’aquesta eina, queda verificada amb els resultats obtinguts en la realització de dues proves pilot en dues zones amb possibilitats de desenvolupar-hi itineraris d’EA. Una de les zones ha quedat descartada, per l’incompliment d’un dels criteris que s’ha definit en el protocol com a imprescindibles pel bon desenvolupament de l’activitat que es planteja. Mentre que en l’altre zona, el compliment de totes aquestes condicions o criteris, fan viable la implantació de l’itinerari d’EA, duent a terme així el seu posterior disseny. Malgrat l’estudi es centri en un espai natural protegit concret, és una eina que pretén ser extrapolable en d’altres espais d’aquesta categoria.
Implementation of IPM programs on European greenhouse tomato production areas: Tools and constraints
Resumo:
Whiteflies and whitefly-transmitted viruses are some of the major constraints on European tomato production. The main objectives of this study were to: identify where and why whiteflies are a major limitation on tomato crops; collect information about whiteflies and associated viruses; determine the available management tools; and identify key knowledge gaps and research priorities. This study was conducted within the framework of ENDURE (European Network for Durable Exploitation of Crop Protection Strategies). Two whitefly species are the main pests of tomato in Europe: Bemisia tabaci and Trialeurodes vaporariorum. Trialeurodes vaporariorum is widespread to all areas where greenhouse industry is present, and B. tabaci has invaded, since the early 1990’s, all the subtropical and tropical areas. Biotypes B and Q of B. tabaci are widespread and especially problematic. Other key tomato pests are Aculops lycopersici, Helicoverpa armigera, Frankliniella occidentalis, and leaf miners. Tomato crops are particularly susceptible to viruses causingTomato yellow leaf curl disease (TYLCD). High incidences of this disease are associated to high pressure of its vector, B. tabaci. The ranked importance of B. tabaci established in this study correlates with the levels of insecticide use, showing B. tabaci as one of the principal drivers behind chemical control. Confirmed cases of resistance to almost all insecticides have been reported. Integrated Pest Management based on biological control (IPM-BC) is applied in all the surveyed regions and identified as the strategy using fewer insecticides. Other IPM components include greenhouse netting and TYLCD-tolerant tomato cultivars. Sampling techniques differ between regions, where decisions are generally based upon whitefly densities and do not relate to control strategies or growing cycles. For population monitoring and control, whitefly species are always identified. In Europe IPM-BC is the recommended strategy for a sustainable tomato production. The IPM-BC approach is mainly based on inoculative releases of the parasitoids Eretmocerus mundus and Encarsia formosa and/or the polyphagous predators Macrolophus caliginosus and Nesidiocoris tenuis. However, some limitations for a wider implementation have been identified: lack of biological solutions for some pests, costs of beneficials, low farmer confidence, costs of technical advice, and low pest injury thresholds. Research priorities to promote and improve IPM-BC are proposed on the following domains: (i) emergence and invasion of new whitefly-transmitted viruses; (ii) relevance of B. tabaci biotypes regarding insecticide resistance; (iii) biochemistry and genetics of plant resistance; (iv) economic thresholds and sampling techniques of whiteflies for decision making; and (v) conservation and management of native whitefly natural enemies and improvement of biological control of other tomato pests.
Resumo:
This article offers a series of reflections and proposals concerning the visitors usage of Catalonia's Natural Parks. The basis of these affirmations is the analysis of the parks which exist at the present in Catalonia, as well as the study of the current legislation in Catalonia and in Spain. Although the article deals exclusively with protected natural areas, it must be remembered that people's recreational activities affect the entire natural environment. It is therefore necessary to extend planning to the impact of such activities in all natural areas. The author proposes as a possible solution a hierarchy of leisure zones in natural spaces, divided into three different levels: Municipal Parks, Regional Parks as well as Natural and National Parks
Resumo:
Using a panel of 48 provinces for four years we empirically analyze a series of temporary policies aimed at curbing fuel consumption implemented in Spain between March and June 2011. The first policy was a reduction in the speed limit in highways. The second policy was an increase in the biofuel content of fuels used in the transport sector. The third measure was a reduction of 5% in commuting and regional train fares that resulted in two major metropolitan areas reducing their overall fare for public transit. The results indicate that the speed limit reduction in highways reduced gasoline consumption by between 2% and 3%, while an increase in the biofuel content of gasoline increased this consumption. This last result is consistent with experimental evidence that indicates that mileage per liter falls with an increase in the biofuel content in gasolines. As for the reduction in transit fares, we do not find a significant effect for this policy. However, in specifications including the urban transit fare for the major cities in each province the estimated cross-price elasticity of the demand for gasoline -used as a proxy for car use- with respect to the price of transit is within the range reported in the literature. This is important since one of the main eficiency justification for subsidizing public transit rests on the positive value of this parameter and most of the estimates reported in the literature are quite dated.
Resumo:
We compare a set of empirical Bayes and composite estimators of the population means of the districts (small areas) of a country, and show that the natural modelling strategy of searching for a well fitting empirical Bayes model and using it for estimation of the area-level means can be inefficient.
Resumo:
Este artículo es una aproximación a los métodos utilizados para analizar, cuantificar y valorar los cambios en los usos y cubiertas del suelo en estos dos valles que forman parte del espacio natural protegido de la Alta Garrotxa. La dinámica vivida en este territorio es un claro ejemplo de los procesos acaecidos a lo largo del siglo XX en buena parte de las áreas de montaña mediterránea. Una dinámica caracterizada fundamentalmentepor un incremento de la superficie forestal en detrimento del espacio agrario. Así mismo se proponen pautas metodológicas para su adecuada cartografía, así como para determinar las áreas potencialmente recuperables de espacio agrario con el objetivo de mantener la diversidad paisajística, biológica y el patrimonio cultural con la ayuda de los SIG y la Ecología del Paisaje
Resumo:
Additions to the vascular flora of the Cadí-Moixeró Natural Park and neighbouring Pre-Pyrenean areas (eastern Iberian Pyrenees) We present about fifty contributions to the catalogue of the vascular flora of the mentioned area, published in 2003. Among the taxa reported, 21 correspond to novelties found in our own field observations or in the literature. We highlight the first records for the Eastern Iberian Pre-Pyrenees of Meconopsis cambrica (L.) Vig. and Omalotheca hoppeana (Koch) Schulz Bip. and F.W. Schulz. Other data refer to rare taxa already included in the catalogue, such as Gagea lutea (L.) Ker Gawl., G. reverchonii Degen, Lappula deflexa (Wahlenb.) Garcke and Minuartia villarii (Balb.) Wilczek and Chenevard.