Comparing the role of site disturbance and landscape properties on understory species richness in fragmented periurban Mediterranean forests

Guirado M., Pino J., Rodà F. (2007) Comparing the role of site disturbance and landscape properties on understory species richness in fragmented periurban Mediterranean forests. Landscape Ecology. 22: 117-129.
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Doi: 10.1007/s10980-006-9009-y

Resum:

We hypothesized that the spatial configuration and dynamics of periurban forest patches in Barcelona (NE of Spain) played a minor role in determining plant species richness and assemblage compared to site conditions, and particularly to both direct (measured at plot level) and potential (inferred from landscape metrics) human-associated site disturbance. The presence of all understory vascular plants was recorded on 252 plots of 100 m2 randomly selected within forest patches ranging in size from 0.25 ha to 218 ha. Species were divided into 6 groups, according to their ecology and conservation status. Site condition was assessed at plot level and included physical attributes, human-induced disturbance and Quercus spp. tree cover. Landscape structure and dynamics were assessed from patch metrics and patch history. We also calculated a set of landscape metrics related to potential human accessibility to forests. Results of multiple linear regressions indicated that the variance explained for non-forest species groups was higher than for forest species richness. Most of the main correlates corresponded to site disturbance variables related to direct human alteration, or to landscape variables associated to indirect human effects on forests: Quercus tree cover (a proxy for successional status) was the most important correlate of non-forest species richness, which decreased when Quercus tree cover increased. Human-induced disturbance was an important correlate of synanthropic and total species richness, which were higher in recently managed and in highly frequented forests. Potential human accessibility also affected the richness of most species groups. In contrast, patch size, patch shape and connectivity played a minor role, as did patch history. We conclude that human influence on species richness in periurban forests takes place on a small scale, whereas large-scale effects attributable to landscape structure and fragmentation are comparatively less important. Implications of these results for the conservation of plant species in periurban forests are discussed. © 2007 Springer Science + Business Media B.V.

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Effect of three-dimension and color contrast on nest localization performance of two solitary bees (Hymenoptera: Megachilidae)

Guédot C., Bosch J., Kemp W.P. (2007) Effect of three-dimension and color contrast on nest localization performance of two solitary bees (Hymenoptera: Megachilidae). Journal of the Kansas Entomological Society. 80: 90-104.
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Doi: 10.2317/0022-8567(2007)80[90:EOTACC]2.0.CO;2

Resum:

We addressed the importance of third dimension and color contrast as cues used in close range nest localization by Osmia lignaria Say and Megachile rotundata (F.) females. By manipulating the surface of the nesting site, we compared 3-dimensional configurations of three different depths (1 cm, 2 cm, and 6 cm) and three different color contrasts (black-black, black-gray, and black-blue). We also tested the relative importance of third dimension and color contrast by manipulating both variables. Both species respond to changes in depth as well as in color contrast by increasing searching time and by displaying behaviors consistent with disorientation. Increasing the depth of the 3-dimensional configuration as well as the amount of color contrast led to an increase in the level of confusion. © 2007 Kansas Entomological Society.

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Pollinator diversity affects plant reproduction and recruitment: The tradeoffs of generalization

Gómez J.M., Bosch J., Perfectti F., Fernández J., Abdelaziz M. (2007) Pollinator diversity affects plant reproduction and recruitment: The tradeoffs of generalization. Oecologia. 153: 597-605.
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Doi: 10.1007/s00442-007-0758-3

Resum:

One outstanding and unsolved challenge in ecology and conservation biology is to understand how pollinator diversity affects plant performance. Here, we provide evidence of the functional role of pollination diversity in a plant species, Erysimum mediohispanicum (Brassicaceae). Pollinator abundance, richness and diversity as well as plant reproduction and recruitment were determined in eight plant populations. We found that E. mediohispanicum was generalized both at the regional and local (population) scale, since its flowers were visited by more than 100 species of insects with very different morphology, size and behaviour. However, populations differed in the degree of generalization. Generalization correlated with pollinator abundance and plant population size, but not with habitat, ungulate damage intensity, altitude or spatial location. More importantly, the degree of generalization had significant consequences for plant reproduction and recruitment. Plants from populations with intermediate generalization produced more seeds than plants from populations with low or high degrees of generalization. These differences were not the result of differences in number of flowers produced per plant. In addition, seedling emergence in a common garden was highest in plants from populations with intermediate degree of generalization. This outcome suggests the existence of an optimal level of generalizations even for generalized plant species. © 2007 Springer-Verlag.

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Implementación de un SIG para la gestión del litoral marítimo Catalan y su difusión en la web.

Serral I, Jordana R (2007) Implementación de un SIG para la gestión del litoral marítimo Catalan y su difusión en la web. Actas de la 7ª Setmana Geomàtica. Sensores de alta resolución y sus aplicaciones [CD_ROM]. 2007. Fitxer: pap090.pdf. D.L. B-9432-2007.

Análisis de la gestión de las plantas exóticas en los espacios naturales españoles.

Andreu J, Vilà M (2007) Análisis de la gestión de las plantas exóticas en los espacios naturales españoles. Ecosistemas 16: 3.

El canvi climàtic i els boscos: mitigació, vulnerabilitat i adaptació.

Terradas J (2007) El canvi climàtic i els boscos: mitigació, vulnerabilitat i adaptació. Catalunya Forestal 84: 20-21.

Aula d’Ecologia. Cicle de conferències 2006.

Avila A, Terradas J (2007) Aula d’Ecologia. Cicle de conferències 2006. Servei de Publicacions Universitat Autònoma de Barcelona, Bellaterra. ISBN 978-490-2485-6.

Effect of differently post-treated dewatered sewage sludge on β-glucosidase activity, microbial biomass carbon, basal respiration and carbohydrates contents of soils from limestone quarries

Jiménez P., Ortiz O., Tarrasón D., Ginovart M., Bonmatí M. (2007) Effect of differently post-treated dewatered sewage sludge on β-glucosidase activity, microbial biomass carbon, basal respiration and carbohydrates contents of soils from limestone quarries. Biology and Fertility of Soils. 44: 393-398.
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Doi: 10.1007/s00374-007-0220-z

Resum:

This work has evaluated the effects of thermally dried (TDS) or composted (CDS) dewatered sewage sludge on β-glucosidase activity, total (TCH) and extractable (ECH) carbohydrate content, microbial biomass carbon and basal respiration of soils from limestone quarries under laboratory conditions. Two doses (low and high) of the dewatered sludge (DS) or of the respective TDS or CDS were applied to a clayey and a sandy soil, both coming from working quarries. The soil mixtures and the controls (soils with no added sludge) were incubated for 9 months at 25°C and 30% of field capacity. The addition of sludge increased all the studied soil parameters, and the increase depended on the amount of sludge. Except in the case of TCH and ECH, the enhancing effect decreased with time, but at the end of incubation, parameters of the treated soils were higher than those of the control. The rank order of the initial stimulating effect was soil-TDS ≥ soil-DS ≥ soil-CDS, and probably, this order depended on the proportion of stable organic matter, which was the lowest in the TDS. Values of metabolic quotient (qCO2) were higher at the lower dose, and they did not change during incubation in the CDS-treated soils. Both TCH and ECH were the parameters with the greatest significant sludge and dose effects. Basal respiration, microbial biomass carbon and β-glucosidase activity were the best measured parameters in distinguishing the long-term effects of the three sludge types over the soils. © 2007 Springer-Verlag.

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Region of Interest coding applied to Map Overlapping in Geographic Information Systems. Geoscience and Remote Sensing Symposium. IGARSS 2007.

Bartrina-Rapesta J, Aulí-Llinàs F, Serra-Sagristà J, Zabala A, Pons X, Masó J (2007) Region of Interest coding applied to Map Overlapping in Geographic Information Systems. Geoscience and Remote Sensing Symposium. IGARSS 2007. IEEE International. pp: 5001 – 5004. Digital Object Identifier 10.1109/IGARSS.2007.4423984

Efecto de la compresión wavelet de imágenes en su fotointerpretación.

Zabala A, Modugno S, Pons X, Buriel JA, Pino J (2007) Efecto de la compresión wavelet de imágenes en su fotointerpretación. Actes de la 7ª Semana Geomática. Edició en CD-ROM. Dipòsit legal: B-9432-2007

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