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Peer Reviewed
See detailEcological and pathological factors related to trace metal concentrations in harbour seal Phoca vitulina in the North Sea
Drouguet, Olivier; Siebert, Ursula; Jauniaux, Thierry ULiege et al

Poster (2005)

During the last decade, recurrent epizootics have affected harbour seal (Phoca vitulina) populations in the North Sea. Recent data on their trophic habits and pollutant levels are of primary importance ... [more ▼]

During the last decade, recurrent epizootics have affected harbour seal (Phoca vitulina) populations in the North Sea. Recent data on their trophic habits and pollutant levels are of primary importance for their conservation. As isotopic composition of an animal is related to that of its prey, δ13C and δ15N were measured by mass spectrometry in the muscles of 66 harbour seals beached along the coasts of France (n = 10), Belgium (n = 30) and Netherlands (n = 26) between 1994 and 2004. Trace metals concentrations (Zn, Cu, Fe, Cd, Hg and Se) were also determined in liver, kidney and muscles by Inducted Plasma Spectrometry. δ13C and δ15N values remained similar between harbour seals from France (-15.7 0/00; 18.7 0/00, respectively), Belgium (-15.7 0/00; 19.0 0/00, respectively) and Netherlands (-14.7 0/00; 18.7 0/00, respectively). These data are in good agreement with their coastal and piscivorous life style. Isotopic value remained similar between males and females and between body conditions. Hg levels were significantly higher in seals from the southern North Sea when compared to previously published data from seals collected in Norway, probably due some geographical differential exposure. Hepatic Hg was positively correlated to hepatic Se, both increasing with the length of the seals. Such a relationship reflected an age accumulation process coupled to a detoxication mechanism involving antagonism between Hg and Se in the liver. No relationship between stable isotopes and Hg and Cd levels was observed. Increasing Zn and Hg hepatic levels were observed with degrading body condition of the harbour seals, which is reflected by decreasing blubber thickness and high hepatic to total body mass ratio. These observations tend to indicate a global redistribution of trace metals from muscle and blubber to liver, as a result of protein and lipid catabolism linked to disease and starvation. [less ▲]

Detailed reference viewed: 37 (1 ULiège)
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See detailEcological approach in regenerative design: Landscape Urbanism as an opportunity to recover industrial abandoned sites in Liège
Baldin, Elisa ULiege

Scientific conference (2016, October 20)

From the second half of the last century ecology has been recognized as one of the most important value in landscape design, together with aesthetics and social involvement (Ian H. Thompson). After a ... [more ▼]

From the second half of the last century ecology has been recognized as one of the most important value in landscape design, together with aesthetics and social involvement (Ian H. Thompson). After a period dominated by the prevalence of the aesthetical values in landscape/gardens conception a new perspective arose: the global growth and the effects of exploitation of natural resources have generated an increasing awareness about the impacts of human life on environment and a reflection on new possible way of living balancing the quality of life and the respect for nature in our territories. The ecological approach has developed thanks to some landscape architects contributions, based on their researches on: the displacement from a more anthropocentric to a more ecocentric view in landscape planning (Ian McHarg) and the introduction of the principles of balance, diversity, sustainability in order to learn to perceive and to design healty landscapes. Working with nature, in landscape urbanism, means to activate processes involving plants, animals and people, with the aim of improving the quality of life in urban environment. Therefore ecology is strictly linked to aesthetical and social aspects: landscape design must relate spatial values, by reinterpreting and enhancing the characters of the places, with social values, by introducing activities to strengthen social interactions. In contemporary landscape design, ecology is interpreted as a key approach, concerning mostly regenerative design (J.T Lyle). This innovative concept considers design as the cultural instrument accompanying and orienting ecological processes. In fact landscape design deals with urban development strategies, interventions on urban fringes, reclamation of waste lands: in all cases arise the necessity to rethink the territories starting from the restoration of an interrupted balance between natural resources and anthropic actions. The ecological approach is based on the use of natural elements and dynamics as a means for transformation of the territories. One powerful effect of these interventions is the capacity to recover the relationship between people and the spirit of the places and sometimes, the possibility to build a new identity, especially in rejected areas, and this is a “catalyst act”, involving society in regenerative design programs. New green structures enhancing environmental qualities and protecting biodiversity, agricultural technologies remediating soils and water are only few of the potentials of landscape ecology. Another important consequence of this innovative approach is the rise of a new aesthetics, as “nature is perceived as a process, not as a scenary” (R.Smithson). Recognizing change and uncertainty as the basic dynamics of landscape (M.Antrop), designers methods and sensitivity appear more effective if based on predicting different and open scenarios. But ecology is not a panacea itself: the risks in ecosystem service approach are several. First, specially in public spaces design, there is the risk of confusing the primary values of the action of planting trees and greenery: some aesthetical choices could not represent the ecological efficiency. This happens very often because the client’s will is more oriented to achieve an immediate effect, where vegetation’s use is equated to a decorative device, instead of a new balance generator one. Similarly, choices based on low maintenance perspective are not always synonymous of ecology. Furthermore, in Urban Planning, prescriptions about greenery and trees plantation follow some quantitative parameters instead of qualitative ones. The contribution of landscape design to Urbanism is based on a multidisciplinary approach which tends to detect and enhance those hidden and overwritten features characterizing the “genius loci”. Thus, ecology represents a site specific aspect and its introduction in landscape urbanism supposes a deep knowledge of the process and its effects on environment and on society. [less ▲]

Detailed reference viewed: 33 (4 ULiège)
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Peer Reviewed
See detailEcological characteristic's of small farmland ponds: Associations with land use practices at multiple spatial scales
Declerck, Steven; De Bie, Tom; Ercken, Dirk et al

in Biological Conservation (2006), 131(4), 523-532

Despite their restricted surface area, small farmland ponds often have a high conservation value because they contribute significantly to regional biodiversity and contain rare or unique species. For this ... [more ▼]

Despite their restricted surface area, small farmland ponds often have a high conservation value because they contribute significantly to regional biodiversity and contain rare or unique species. For this reason, the creation of new ponds has become a widely applied practice in many countries. information on the effects of land use on farmland ponds is very scarce. Farmland ponds differ from larger ponds, lakes and livers in many aspects and can therefore be expected to be affected by land use via other mechanisms operating at different spatial scales. We here present a study on 126 ponds distributed over the entire territory of Belgium (surface area: 30.500 km(2)). We assessed variables related to turbidity state and vegetation complexity and related them to land use variables assessed at several spatial scales ranging from the pond edge up to 32 km(2) circular areas. According to redundancy analysis, trampling by cattle and percentage cover of nearby crop land were positively associated with turbid state related variables. Conversely, ponds with high coverage by forest in the immediate neighbourhood tended to be more associated with the clear water state. Multiple regression analysis demonstrated a negative effect of trampling and coverage by crop land on vegetation complexity. Effects of crop lands and forest were strongest at the local scale (< 200 m radius) which indicates that adverse external influences can most efficiently be mitigated at a small scale. Based on these results we suggest several recommendations for pond construction and conservation. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 64 (2 ULiège)
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See detailEcological characterization of Lophira alata (Ekki), a vulnerable timber tree species, in order to develop silvicultural effective strategies
Biwole, Achille ULiege; Doucet, Jean-Louis ULiege

Poster (2011, December 02)

Ekki, Lophira alata Banks ex C.F.Gaertn., is an African timber species occurring in tropical rainforests. Of important commercial value, this species is logged for its excellent timber properties and has ... [more ▼]

Ekki, Lophira alata Banks ex C.F.Gaertn., is an African timber species occurring in tropical rainforests. Of important commercial value, this species is logged for its excellent timber properties and has been classified by the IUCN as «vulnerable" species. As for many other tropical tree species, the commercial exploitation of Ekki is confronted to an insufficient knowledge about the species’ ecological profile. With a distribution range limited to the Guinea-Congolian region, Ekki often displays insufficient natural regeneration, but the biotic and abiotic factors explaining this deficiency have been hardly characterized. This lack of knowledge makes it difficult to model the population dynamics on the long term. The reproductive biology of Ekki and the genetic variability of its population remains poorly studied too. To address this situation, a fundamental and applied research is being undertaken in the forest concessions managed by Wijma Cameroun SA., covering over 250,000 hectares of rainforest in Southern Cameroon. This study aims to answer four essential questions: (1) what is the phylogenetic relationship between L. alata and L. lanceolata, (2) how paleoclimate and human disturbances impact its distribution and abundance, (3) how to these populations respond to logging over several rotation periods, (4) does logging promote or inhibit the natural regeneration of the species. Several study devices have thus been installed to collect the data needed to improve the characterization of Ekki’s ecology and to conceive silvicultural strategies. [less ▲]

Detailed reference viewed: 115 (23 ULiège)
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Peer Reviewed
See detailEcological diversity of damselfishes (Pomacentridae) from Moorea
Gajdzik, Laura ULiege; Parmentier, Eric ULiege; Lepoint, Gilles ULiege et al

Poster (2014, December)

The Pomacentridae (damselfishes) represents the 3rd most species-rich coral reef fish family, including 394 species spread worldwide. Recent studies suggested that damselfishes iteratively evolve along ... [more ▼]

The Pomacentridae (damselfishes) represents the 3rd most species-rich coral reef fish family, including 394 species spread worldwide. Recent studies suggested that damselfishes iteratively evolve along three main trophic guilds: “the pelagic feeders” feeding mainly on zooplankton, “the benthic feeders” grazing filamentous algae or biting coral polyps, and an “intermediate” group with species feeding on zooplankton, small benthic invertebrates and algae in variable proportions. Comparing the ecological diversity of damselfish communities among various geographical regions could assess such an iterative radiation. Within this context, the present study is a first attempt exploring the trophic diversity of damselfish community at Moorea Island (French Polynesia). The relationship between the trophic guilds, their habitat diversity and their behavior is evaluated. Habitat and behaviour of 16 damselfish species were described during transects along which different kinds of data were collected. For examples, the location within the reef (e.g. fringing or barrier reef), the depth, the substrate over which fishes are living or the solitary/gregarious habits were recorded. Diet of individuals was investigated by means of stomach content and stable isotopes analyses. Correlations between the dietary preferences and ecological data (habitat and behaviour) are given and the ecological diversity among trophic groups is compared. [less ▲]

Detailed reference viewed: 60 (11 ULiège)
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Peer Reviewed
See detailEcological fitness of Bacillus subtilis BGS3 regarding production of the surfactin lipopeptide in the rhizosphere
Nihorimbere, Venant ULiege; Fickers, Patrick ULiege; Thonart, Philippe ULiege et al

in Environmental Microbiology Reports (2009), 1(2), 124-130

Cyclic lipopeptides and particularly surfactins produced by Bacillus species retain antibacterial, antiviral, biofilm-forming and plant resistance-inducing activities. In most cases, their role in ... [more ▼]

Cyclic lipopeptides and particularly surfactins produced by Bacillus species retain antibacterial, antiviral, biofilm-forming and plant resistance-inducing activities. In most cases, their role in biological control of plant diseases was evoked on the basis of in vitro assays or by using non-producing/ overproducing mutants but there is a need for more direct evidence of an efficient lipopeptide biosynthesis in the rhizosphere. In this work, we coupled LC-MS quantification of the lipopeptides secreted by cells colonizing tomato plants with the use of psrfA– lacZ reporter system integrated within the BGS3 chromosome to study the expression of the surfactin operon in planta. Results showed that a higher level of psrfA induction was observed upon the establishment of a stable BGS3 population on roots and surfactins extracted from the rhizosphere were produced in biologically significant quantities. Our results also demonstrate that BGS3 efficiently utilizes the main substrates from plant exudates to produce surfactins. This synthesis is also efficient in cells forming colonies and the production may be favoured in bacteria developing slowly in the rhizosphere. This provides a first understanding of how environmental factors may influence lipopeptide production by beneficial Bacillus strains. [less ▲]

Detailed reference viewed: 115 (25 ULiège)
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See detailEcological functionality in agriculture
Pécheur, Emilie ULiege

Poster (2014, December 17)

Detailed reference viewed: 26 (0 ULiège)
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Peer Reviewed
See detailEcological impact of habitat loss on African landscapes and diversity
Vranken, Isabelle ULiege; Djibu Kabulu, J P; Munyemba Kankumbi, F et al

in Daniels, J A (Ed.) Advances in environmental research, volume 14 (2011)

Detailed reference viewed: 108 (31 ULiège)
See detailEcological impact of the opportunist northern pigtailed macaques (Macaca leonina) in degraded environments: Ranging pattern, seed dispersal and predatory behavior in Central Thailand
Gazagne, Eva ULiege

Conference (2015, December 01)

Deforestation and fragmentation have become the most important threats for biodiversity due to both plant and animal dispersal movement limitation impacting seed dispersal and prey-predator interactions ... [more ▼]

Deforestation and fragmentation have become the most important threats for biodiversity due to both plant and animal dispersal movement limitation impacting seed dispersal and prey-predator interactions. Through the study of the adaptive and opportunistic northern pigtailed macaque (Macaca leonina), this PhD aims to assess how fragmentation affects the macaques’ habitat use, seed dispersal and predatory behavior in a highly fragmented and degraded environment (Sakaerat Biosphere Reserve, Central Thailand). Investigating the ranging pattern and feeding behavior of this macaque, acknowledged as an effective seed disperser, in a disturbed environment, will provide a concrete example of potential forest regeneration by a natural agent. Moreover, as this is a very efficient passerine nest predator, the study of its ranging behavior will allow assessing the extent of a generalist predator efficiency in a fragmented environment. [less ▲]

Detailed reference viewed: 11 (3 ULiège)
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See detailEcological impacts of an invasive species in Wallonie, the raccoon Procyon lotor
Campos-Martinez, Irène; Gautherot, J.; Lambinet, Clotilde ULiege et al

Poster (2013, August)

Detailed reference viewed: 45 (11 ULiège)
Peer Reviewed
See detailEcological Impacts of Invasive Plant Species
Vanderhoeven, Sonia ULiege

Conference (2007)

Detailed reference viewed: 11 (0 ULiège)
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Peer Reviewed
See detailEcological intensification of fish production : Fertilization strategies in Africa fish farms
Mafwila Kinkela, Patrick ULiege; Kambashi Mutiaka, Bienvenu ULiege; Rollin, Xavier et al

Poster (2017, February)

Ponds fertilization has been found as strategies of intensification fish production for farm in Africa were commercial feeds are not available and ingredients for formulate completed feed are cost ... [more ▼]

Ponds fertilization has been found as strategies of intensification fish production for farm in Africa were commercial feeds are not available and ingredients for formulate completed feed are cost. However, farmers are not safe to any danger because the efficiency of these strategies is not always known owing to the associated risk of eutrophication. An experience was making to assess how various fertilization practices would impact fish growth and physicochemical parameters of water in the pond. [less ▲]

Detailed reference viewed: 35 (1 ULiège)
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Peer Reviewed
See detailEcological modeling and paedomorphosis: a study case in Montenegrin newts
Denoël, Mathieu ULiege; Ficetola, Gentile; Cirovic, Rusa et al

Poster (2009)

Detailed reference viewed: 25 (2 ULiège)