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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Boxing for biodiversity: a long-term follow up of an artificial dead wood environment

Carlsson, Staffan January 2015 (has links)
Today many saproxylic species are threatened because of habitat decline in Europe. Hollow trees represent a great part of the habitats that saproxylic species use. Since hollows takes a long time to develop, management actions are needed to prevent the extinction of saproxylic species. The aim of this study was to investigate the succession of saproxylic beetle species in artificial habitats in the form of wooden boxes. Wooden boxes were filled with a potential substrate and placed at different distances (0-1800 m) from oak hollow hot spots. In addition to the start mixture, four different additional substrates were added. In total, 4510 specimens of 114 saproxylic beetle species were sampled in 43 boxes over ten years. The specimens of tree-hollow species, wood rot species and nest species increased with 38% from the fourth to the final year but species richness decline from 47 to 29, respectively. A dead hen had a tendency for attracting more species but the small effect of different added substrates diminished over the years and had no significant effect on species richness after ten years. There was a higher similarity in species richness after ten years between the boxes and real hollow oaks. In conclusion, the artificial habitat developed into a more hollow like environment, with fewer but more abundant wood mould specialists, during ten years. This study clearly shows that the wooden boxes are used as habitats for saproxylic species as the boxes seems to develop into a more hollow-like habitat with time.
2

Boxes with artificial habitats support saproxylic beetles in green areas near and within cities

Ryding, Caroline January 2020 (has links)
The highest terrestrial biodiversity in Sweden is connected to old grown deciduous trees with tree trunk hollows and dead wood, such as oak and maple. A reduction of deciduous forest and old grown trees from anthropological activities has left many habitats wanting in size and fragmented. Many saproxylic species that are dependent on old grown trees with tree trunk hollows are now threatened. The aim of this study was to further develop artificial habitats (boxes) used for conservation of saproxylic beetles. The boxes were made larger, placed in cities’ green areas and filled with produce from the surrounding areas. The study assessed the effectiveness of these boxes, regarding species richness and composition, compared with earlier studies and tree trunk hollows. The study also aimed to assess what variables might affect the species richness and family and species composition. During April to August 2019, 3454 individuals of 105 saproxylic species were collected in 55 boxes. Of the species dependent on tree trunk hollows, 45% were found in the boxes, compared with tree trunk hollows. Of the variables included shading of the box, the amount of buildings surrounding the box and the amount of forest surrounding the box were found to affect species richness. More shading and a larger forest area increased the species richness in the boxes, and a higher concentration of buildings decreased species richness in the boxes. Conclusively, this study showed that boxes placed in cities’ green areas could act as an alternative habitat for saproxylic beetles.
3

Les zones portuaires peuvent-elles servir de nourriceries alternatives pour les poissons marins côtiers ? : cas des sars en Méditerranée Nord-occidentale / Potential use of ports as alternative nursery habitats by coastal marine fishes : Insights from Diplodus species in the Northwestern Mediterranean

Bouchoucha, Marc 13 December 2017 (has links)
Au cours de leur cycle de vie, la plupart des espèces de poissons marins côtiers passent par des nourriceries littorales dont la qualité influence largement le succès du recrutement et donc le maintien de l’abondance de leurs populations. Or, la construction de ports entrain irrémédiablement une perte de fonction pour les habitats côtiers impactés. Dans ce contexte,l’objectif général de cette thèse était de voir si les zones portuaires peuvent malgré tout servir de nourriceries alternatives pour les poissons marins côtiers. Pour cela, les abondances des juvéniles de quatre espèces de sars, du genre Diplodus, ont d’abord été suivies dans cinq ports méditerranéens. Ceci a permis de montrer que ces espèces côtières peuvent s’installer et grandir avec succès dans les ports. La complexification de la structure 3D de l’habitat augmente sensiblement les abondances de juvéniles. Dans un second temps, la croissance, la condition et les niveaux de contamination desjuvéniles de deux espèces de sars (D. sargus et D. vulgaris) ont été comparés entre différents ports et habitats naturels de la rade de Toulon. Ceci a montré que la croissance et la condition des juvéniles peut être équivalente dans certains ports et dans les zones naturelles adjacentes, avec des niveaux de contamination faibles, même dans les zones les plus polluées. Enfin, la composition multi- élémentaire des otolithes des juvéniles de D. sargus et D. vulgaris a été comparée entre trois ports et deux zones naturelles de la rade de Toulon. Aucun élément chimique lié aux activités portuaires n’aété retrouvé en plus forte concentration dans les otolithes des juvéniles issus des ports. Il n’existe donc pas une signature unique caractéristique de l’ensemble des ports. La composition chimique des otolithes peut néanmoins être utilisée pour étudier la contribution relative des ports aux stocks d’adultes à condition de caractériser la signature de l’ensemble des habitats juvéniles potentiels. L’ensemble des résultats acquis indiquent que les ports peuvent être utilisés comme nourriceries alternatives par plusieurs espèces de poissons marins côtiers. Les projets d’ingénierie écologiquevisant à augmenter la complexité structurale des habitats portuaires sont des pistes intéressantes pour maintenir la biodiversité côtières et les stocks de poissons. / During their life cycle, most of the marine coastal fish species use nursery grounds which quality influence their recruitment and then the conservation of their populations. However, the construction of ports impair irremediably fish nursery function of the coastal areas impacted. The ultimate aim of the PhD research was to assess if ports could provide suitable alternative nursery habitats for coastal fish species. Firstly, abundances of the juveniles of four Diplodus species were surveyed in five marinas located along the French Mediterranean coast. This showed that coastal fishes can successfully settle and grow inside these artificialized coastal areas. Moreover, increasing the complexity of port habitats can considerably enhance their suitability for juveniles, especially at the youngest stages. Secondly, body condition, growth rate and metal contamination in the juveniles of two Diplodus species (D. sargus and D. vulgaris) were compared between different ports and natural areas in the Bay of Toulon. Juvenile growth and condition can be equivalent between fish collected from ports and from adjacent natural areas. Contamination levels in fish were low, even in highly polluted areas. Finally, otolith composition in the juveniles of D. sargus and D. vulgaris was investigated in three ports and two natural areas in the Bay of Toulon. None of the port related had systematically higher concentrations in otoliths from Diplodus juveniles collected in ports. Therefore, otolith microchemistry cannot provide a unique and reliable fingerprint discriminating ports and natural areas. Nevertheless, otolith microchemistry could provide an effective natural tag to determine the contribution of ports to adult stocks provided that a library of all potential juvenile habitat fingerprints is established. All these results confirm that ports can be used as alternative nursery habitats by marine coastal fishes. Ecological engineering projects aiming at increasing structural complexity of port habitats seem promising for biodiversity and fish stock conservation.
4

Panoramic Sham

Vail, Andrea 08 May 2014 (has links)
Panoramic Sham is sunset and sunrise, a walk through a field of wildflowers or a day in the forest. It is that moment when a light breeze tousles your hair and chirping birds reaffirm vitality. Panoramic Sham is also a heap of outdated home goods that once transformed our living rooms into artificial habitats. I reimagine decommissioned domestic goods as a way to confront trends of mass-production, habits of consumption and to explore systems of artifice, authenticity, and the consumer haze perpetuated by contemporary American society. Comprised of synthetic materials and manufactured to impersonate nature, these 20th century cast-offs provide an abundant cycle of cultural and generational refuse.

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