Search results for "HABITAT"

Selection of spawning substratum by European river lampreys (Lampetra fluviatilis) in experimental tanks

2014

The selection of spawning substratum by the river lamprey (Lampetra fluviatilis) was studied in two experimental tanks with different flow conditions. In both tanks, four gravel sizes mixed with 15% sand were available to the test animals. In the tank with the lower current speed, lampreys selected in favour of the finest (2–8 mm) gravel size available against gravel sizes 4–20 mm and 8–40 mm. Selection was also significantly different in the tank with higher current speed where selection against the medium-sized substratum (4–20 mm) was evident, but there were no differences between selection for gravel sizes 2–8 mm, 2–40 mm and 8–40 mm relative to availability. Substratum selection and ob…

Lotic life stages of the European river lamprey (Lampetra fluviatilis) : anthropogenic detriment and rehabilitation

2015

Dispersal ecology of deadwood organisms and connectivity conservation

2018

Limited knowledge of dispersal for most organisms hampers effective connectivity conservation in fragmented landscapes. In forest ecosystems, deadwood‐dependent organisms (i.e., saproxylics) are negatively affected by forest management and degradation globally. We reviewed empirically established dispersal ecology of saproxylic insects and fungi. We focused on direct studies (e.g., mark‐recapture, radiotelemetry), field experiments, and population genetic analyses. We found 2 somewhat opposite results. Based on direct methods and experiments, dispersal is limited to within a few kilometers, whereas genetic studies showed little genetic structure over tens of kilometers, which indicates long…

Developing and comparing methods for mapping habitat types and conservation values using remote sensing data and GIS methods

2014

L’habitat du Néolithique final de Quinssaines, Le Bournadiau : approche spatiale et fonctionnelle d'un site au Nord-Ouest de l'Allier.

2011

A late Neolithic settlement was explored during excavations in the northeast of the Allier département, at Bournadiau near Quinsaines, in 2007. Despite erosion, the excavation revealed a ditch and traces of two buildings. The ceramic assemblage and the stone tool industry, partly imported from Grand Pressigny, illustrate the contacts between the inhabitants and the cultural groups from Western-Central (Artenac) and Northern France (Gord). An unusual deposit of seventeen Grand Pressigny flint objects, discovered in the foundations of a small building, provides information about the redistribution process of such products and shows that the site probably functioned in collaboration with the G…

Limits to Arbitrage and Interest Rates: a Debate Between Keynes, Hawtrey and Hicks

2018

International audience; This paper deals with a debate between Hawtrey, Hicks and Keynes concerning the capacity of the central bank to influence the short-term and the long-term rates of interest. Both Hawtrey and Keynes considered the central bank’s ability to influence short-term rates of interest. However, they do not put the same emphasis on the study of the long-term rates of interest. According to Keynes, long-term rates are influenced by future expected short-term rates (1930, 1936), whereas for Hawtrey (1932, 1937, 1938), long-term rates are more dependent on the business cycle. Short-term rates do not have much effect on long-term rates according to Hawtrey. In 1939, Hicks enters …

Niche position drives interspecific variation in occupancy and abundance in a highly-connected lake system

2019

Highlights • We studied interspecific variation in occupancy and abundance of freshwater species. • Occupancy and abundance correlated positively for both diatoms and macroinvertebrates. • Niche position had clearest effects on variation in occupancy and abundance. • The more marginal the niche position, the rarer a species is. We examined how niche position, niche breadth, biological traits and taxonomic relatedness affect interspecific variation in occupancy and abundance of two commonly-used biological indicator groups, i.e. diatoms and macroinvertebrates. We studied 291 diatom and 103 macroinvertebrate species that occupied the littoral zones of a large (305 km2) highly-connected freshw…

Aggregating protected habitats embraces implicit habitat conservation triage

2014

Osoba pozostająca we wspólnym pożyciu na tle doktryny i judykatury w prawie karnym materialnym i procesowym

2017

Changement climatique et suivi de la biodiversité marine côtière aux Iles Kerguelen

2018

Nearshore marine habitats of the French sub-Antarctic islands concentrate a rich and unique biodiversity that is currently facing climate change and its still not well-understood and multifaceted effects. Understanding the impact of these changes and predicting the potential response of ecosystems requires advanced knowledge of marine life and the achievement of uninterrupted and long-term observing programs. The Proteker program, no. 1044 of the French Polar Institute Paul-Émile Victor, has been developped in partnership with the National Nature Reserve of French Southern Territories in order to establish an observatory of coastal marine biodiversity in the Kerguelen Islands and evaluate t…