Examining the role of landscape structure and dynamics in alien plant invasion from urban Mediterranean coastal habitats

Basnou C., Iguzquiza J., Pino J. (2015) Examining the role of landscape structure and dynamics in alien plant invasion from urban Mediterranean coastal habitats. Landscape and Urban Planning. 136: 156-164.
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Doi: 10.1016/j.landurbplan.2014.12.001

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This paper aims to disentangle the effects of both current landscape structure and recent land use-change on alien plant invasion in urban Mediterranean coastal habitats. Patches of four habitat types (rock outcrops, sand dunes, scrublands and forests) of different sizes and surrounding landscape compositions were selected along the coast of the Metropolitan Region of Barcelona (NE Spain). Attributes of habitat patches, historical (1956) and current landscape composition around them, land-cover changes (1956-2005) and other environmental and geographic factors within these patches were obtained. The association of these attributes with alien plant richness, abundance and composition was investigated using GLM and CCA. Alien species richness was mostly explained by patch size and shape and built-up area proportion from 1956 and 2005 in a 50. m buffer around patches. Alien species abundance was mostly related to patch shape, temperature, rainfall, land-cover changes within patches and cropland cover of 1956 in a 50. m buffer around patches. Alien species composition was primary related to habitat type, temperature, land-cover changes within patches and the composition of the surrounding landscape. Results suggest that landscape factors affect alien species richness and abundance differently, which are indicative of species colonization and spread, respectively. Landscape history positively affects both colonization and spread, with evidence for a colonization credit related with past urban cover, and the association between recent patch dynamics and present aliens spread. Results highlight the importance of including landscape structure and dynamics in the management of plant invasions in coastal Mediterranean habitats, especially in metropolitan regions. © 2014 Elsevier B.V.

Llegeix més

Of niche differentiation, dispersal ability and historical legacies: What drives woody community assembly in recent Mediterranean forests?

Basnou C., Vicente P., Espelta J.M., Pino J. (2015) Of niche differentiation, dispersal ability and historical legacies: What drives woody community assembly in recent Mediterranean forests?. Oikos. : 0-0.
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Doi: 10.1111/oik.02534

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Community assembly rules have been extensively studied, but its association with regional environmental variation and land use history remains largely unexplored. Land use history might be especially important in Mediterranean forests, considering their historical deforestation and recent afforestation. Using forest inventories and historical (1956) and recent (2000) land cover maps, we explored the following hypotheses: 1) woody species assembly is driven by environmental factors, but also by historical landscape attributes; 2) recent forests exhibit lower woody species richness than pre-existing due to the existence of colonization credits; 3) these credits are modulated by species' life-forms and dispersal mechanisms. We examined the association of forest historical type (pre-existing versus recent) with total species richness and that of diverse life-forms and dispersal groups, also considering the effects of current environment and past landscape factors. When accounting for these effects, no significant differences in woody species richness were found between forest historical types except for vertebrate-dispersed species. Species richness of this group was affected by the interaction of forest historical type with distance to coast and rainfall: vertebrate-dispersed species richness increased with rainfall and distance to the coast in recent forests, while it was higher in dryer sites in pre-existing forests. In addition, forest historical types showed differences in woody species composition associated to diverse environmental and past landscape factors. In view of these results we can conclude that: 1) community assembly in terms of species richness is fast enough to exhaust most colonization credit in recent Mediterranean forests except for vertebrate-dispersed species; 2) for these species, colonization credit is affected by the interplay of forest history and a set of proxies of niche and landscape constraints of species dispersal and establishment; 3) woody species assemblage is mostly shaped by the species' ecological niches in these forests. © 2015 The Authors.

Llegeix més

Ecosystem services provided by green infrastructure in the urban environment

Basnou, C., Pino, J., Terradas, J. (2015) Ecosystem services provided by green infrastructure in the urban environment. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 10: 0-0.
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Doi: 10.1079/PAVSNNR201510004

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A multivariate fractional regression approach to modeling land use and cover dynamics in a Mediterranean landscape

Molowny-Horas R., Basnou C., Pino J. (2015) A multivariate fractional regression approach to modeling land use and cover dynamics in a Mediterranean landscape. Computers, Environment and Urban Systems. 54: 47-55.
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Doi: 10.1016/j.compenvurbsys.2015.06.001

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The way landscapes change in time reveal a great deal of information about the interplay between the forces of nature and the impact of human-driven changes in a Mediterranean landscape. To understand the dynamics behind the process of polygon fragmentation in land use and cover vector maps we illustrate the potential of a novel regression methodology to cope with multivariate fractional data.An overlay of two vector-based land cover maps separated by a time interval of several years (1956 and 1993) show polygons that have become fragmented. Those fragments thus form a multivariate fractional bounded data set. An extension of the Papke and Wooldridge (1996) fractional regression estimation to the case of multivariate response variables has been subsequently developed to study the processes of polygon fragmentation between the two land use and cover maps.The methodology has been applied to a representative set of vector maps from the Barcelona province, Spain. Several explanatory variables have been used, among them the land cover type of the most important adjacent 1956 polygon. The results of our study indicate that the dynamics of fragmentation are determined not only by geographical and environmental variables but also by the neighboring landscape. We discuss its potential use when employed with techniques of landscape modeling. © 2015 Elsevier Ltd.

Llegeix més

Satellite data as indicators of tree biomass growth and forest dieback in a Mediterranean holm oak forest

Ogaya R., Barbeta A., Basnou C., Penuelas J. (2015) Satellite data as indicators of tree biomass growth and forest dieback in a Mediterranean holm oak forest. Annals of Forest Science. 72: 135-144.
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Doi: 10.1007/s13595-014-0408-y

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• 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 dieback. © 2014, INRA and Springer-Verlag France.

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