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Université de Neuchâtel

Factors modulating cottongrass seedling growth stimulation to enhanced nitrogen and carbon dioxide : compensatory tradeoffs in leaf dynamics and allocation to meet potassium-limited growth

Siegenthaler, Andy ; Buttler, Alexandre ; Grosvernier, Philippe ; Gobat, Jean-Michel ; Nilsson, Mats B. ; Mitchell Edward A. D.

In: Oecologia, 2013, vol. 171, no. 2, p. 557-570

Eriophorum vaginatum is a characteristic species of northern peatlands and a keystone plant for cutover bog restoration. Understanding the factors affecting E. vaginatum seedling establishment (i.e. growth dynamics and allocation) under global change has practical implications for the management of abandoned mined bogs and restoration of their C-sequestration function. We studied...

Université de Neuchâtel

Situation de la vigne sauvage Vitis vinifera ssp. silvestris en Europe = Occurrence ofthe wild vine Vitis vinifera ssp. silvestris m Europe

Arnold, Claire ; Gillet, François ; Gobat, Jean-Michel

In: Vitis, 1998, vol. 37, no. 4, p. 159-170

This paper summarizes the occurrence of the European wild vine - Vitis vinifera L. ssp. silvestris (Gmelin) Hegi – from bibliography and observations made in the framework of research on its ecology in the alluvial and colluvial forests of Europe. The state of the wild vine is disquieting within most of the European countries; in some countries we noticed a lack of recent reliable...

Université de Neuchâtel

Structure of microbial communities in Sphagnum peatlands and effect of atmospheric carbon dioxide enrichment

Mitchell, Edward A. D. ; Gilbert, Daniel ; Buttler, Alexandre ; Amblard, Christian ; Grosvernier, Philippe ; Gobat, Jean-Michel

In: Microbial Ecology, 2003, vol. 46, no. 2, p. 187-199

Little is known about the structure of microbial communities in Sphagnum peatlands, and the potential effects of the increasing atmospheric C02 concentration on these communities are not known. We analyzed the structure of microbial communities in five Sphagnum-dominated peatlands across Europe and their response to C02 enrichment using miniFACE systems. After...

Université de Neuchâtel

Horizontal Distribution Patterns of Testate Amoebae (Protozoa) in a Sphagnum magellanicum Carpet

Mitchell, Edward A. D. ; Borcard, Daniel ; Buttler, Alexandre J. ; Grosvernier, Philippe ; Gilbert, Daniel ; Gobat, Jean-Michel

In: Microbial Ecology, 2000, vol. 39, no. 4, p. 290-300

The distribution of soil microorganisms is generally believed to be patchy and to reflect habitat heterogeneity. Despite this general rule, the amount of existing data on species distribution patterns is scarce. Testate amoebae (Protozoa; Rhizopoda) are an important component of soil microbial communities and are increasingly used in ecological and paleoecological studies of...

Université de Neuchâtel

The palaeoecological history of the Praz-Rodet bog (Swiss Jura) based on pollen, plant macrofossils and testate amoebae (Protozoa)

Mitchell, Edward A. D. ; van der Knaap, W. O. ; van Leeuwen, Jacqueline F.N. ; Buttler, Alexandre ; Warner, Barry G. ; Gobat, Jean-Michel

In: The Holocene, 2001, vol. 11, no. 1, p. 65-80

Stratigraphy, radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae were used to reconstruct the development and ecology of a small raised bog in a karst-dominated landscape in the Swiss Jura Mountains. Special focus was on past vegetation and on the history of Pinus rotundata in relation to anthropogenic and climatic influences. Testate amoebae were used to...

Université de Neuchâtel

Spatio-temporal pattern of bog pine (Pinus uncinata var. rotundata) at the interface with the Norway spruce (Picea abies) belt on the edge of a raised bog in the Jura Mountains, Switzerland

Freléchoux, François ; Buttler, Alexandre ; Schweingruber, Fritz H. ; Gobat, Jean-Michel

In: Annals of Forest Science, 2004, vol. 61, no. 4, p. 309-318

In a bog site in way of paludification, a pine stand is declining, which presently is an infrequent phenomenon on the Swiss Jura scale. A transect was positioned in the bog, from the external and driest part (pine-spruce stand) towards the central and wettest part (pine stand). Water table, tree structure, tree age structure and pine radial growth were analysed with spatial and temporal...

Université de Neuchâtel

White lupin leads to increased maize yield through a soil fertility-independent mechanism: a new candidate for fighting Striga hermonthica infestation?

Weisskopf, Laure ; Akello, Pollycarp ; Milleret, Roxane ; Khan, Zeyaur R. ; Schulthess, Fritz ; Gobat, Jean-Michel ; Le Bayon, Renée-Claire

In: Plant and Soil, 2009, vol. 319, no. 1-2, p. 101-114

Nitrogen (N)-deficiency and lack of phosphorus (P) availability are major constraints to maize yields in Western Kenya. In a two-season field study in the lake Victoria basin, we tested the capacity of white lupin (Lupinus albus (L.), cv. Ultra), as a nitrogen-fixing crop with a highly efficient P-acquisition capacity, to increase maize yields when used as a companion or cover crop,...

Université de Neuchâtel

Influence of some physicochemical and biological parameters on soil structure formation in alluvial soils

Bullinger-Weber, G. ; Le Bayon, Renée-Claire ; Gobat, Jean-Michel ; Guenat, Claire

In: European Journal of Soil Biology, 2007, vol. 43, no. 1, p. 47-70

This study examines the role of abiotic (texture, calcium carbonates or iron) and biotic parameters (earthworm and enchytraeid activities) on the initial phases of soil aggregation. Our research focused on humus forms in alluvial soils, which are considered as young and heterogeneous environments. We hypothesized that the soil structure formation is determined by both the nature of the recent...

Université de Neuchâtel

Ecological conditions for Saxifraga hirculus in Central Europe: A better understanding for a good protection

Vittoz, Pascal ; Gobat, Jean-Michel ; Wyss, Tania

In: Biological Conservation, 2006, vol. 131, no. 4, p. 594-608

Saxifraga hirculus is a postglacial relict in Central Europe, whose populations suffered a dramatic decrease in the 19th and 20th centuries. However, few researchers have been interested in its ecological requirements in Central Europe. This article synthesizes previous knowledge supplemented by original data from the last large population (Switzerland). S. hirculus is a weak...

Université de Neuchâtel

Spatial and Seasonal Patterns of Cattle Habitat use in a Mountain Wooded Pasture

Kohler, Florian ; Gillet, François ; Reust, Stéphanie ; Wagner, Helene H. ; Gadallah, Fawziah ; Gobat, Jean-Michel ; Buttler, Alexandre

In: Landscape Ecology, 2006, vol. 21, no. 2, p. 281-295

Management-oriented models of cattle habitat use often treat grazing pressure as a single variable summarizing all cattle activities. This paper addresses the following questions: How does the spatial pattern of cattle effects vary between cattle activities in a highly heterogeneous landscape? Do these patterns change over the grazing season as forage availability decreases? What are the...