Search results for "IH"
showing 10 items of 9382 documents
Designer ecosystems : A solution for the conservation-exploitation dilemma
2016
Increase in human population is accelerating the rate of land use change, biodiversity loss and habitat degradation, triggering a serious threat to life supporting ecosystem services. Existing strategies for biological conservation remain insufficient to achieve a sustainable human-nature relationship and this situation has fueled a debate on the conservation-exploitation dilemma. We need to devise novel strategies, in a mutually inclusive way, which can support biological conservation and secure economic development of deprived populations. Here we propose the use of designer ecosystems which can ensure ecological sustainability while providing ample and some new means of livelihood to loc…
Phylogeography and Molecular Evolution of Potato virus Y
2012
Potato virus Y (PVY) is an important plant pathogen, whose host range includes economically important crops such as potato, tobacco, tomato, and pepper. PVY presents three main strains (PVYO, PVYN and PVYC) and several recombinant forms. PVY has a worldwide distribution, yet the mechanisms that promote and maintain its population structure and genetic diversity are still unclear. In this study, we used a pool of 77 complete PVY genomes from isolates collected worldwide. After removing the effect of recombination in our data set, we used Bayesian techniques to study the influence of geography and host species in both PVY population structure and dynamics. We have also performed selection and…
Evidence of a highly complex phylogeographic structure on a specialist river bird species, the dipper (Cinclus cinclus)
2008
This study details the phylogeographic pattern of the white-throated dipper (Cinclus cinclus), a Palearctic, temperate, passerine bird that is exclusively associated with flowing water. Our results reveal a complex phylogeographic structure with at least five distinct lineages for the Western Palearctic region. As for many species of the Western Palearctic fauna and flora, this genetic structure is probably linked to the isolation of populations in different southern refuges during glacial periods. Furthermore, the isolation of populations in Scandinavia and/or Eastern regions, but also in Morocco and probably in Corsica, was accentuated by ecological and biogeographic barriers during Quate…
Voles and weasels in the boreal Fennoscandian small mammal community : What happens if the least weasel disappears due to climate change?
2019
Climate change, habitat loss and fragmentation are major threats for populations and a challenge for individual behavior, interactions and survival. Predator–prey interactions are modified by climate processes. In the northern latitudes, strong seasonality is changing and the main predicted feature is shortening and instability of winter. Vole populations in the boreal Fennoscandia exhibit multiannual cycles. High amplitude peak numbers of voles and dramatic population lows alternate in 3–5‐year cycles shortening from North to South. One key factor, or driver, promoting the population crash and causing extreme extended lows, is suggested to be predation by the least weasel. We review the ar…
Grasslands provide diverse opportunities for bird species along an urban-rural gradient
2021
Urbanisation is a major cause of biodiversity loss but careful habitat management and provision of green space within cities can help to mitigate its negative effects. Grasslands occupy large surface areas and have many functions but only a few studies have begun to explore how birds exploit these habitats in urban contexts. We hypothesized that the value of grasslands for nesting and feeding birds is likely to depend both on landscape context, and on local characteristics (grassland size, use and vegetation structure). We surveyed local habitat characteristics, breeding bird presence, abundance and foraging activity in 47 grassland sites, distributed along an urban-rural gradient in two Fr…
Larval intraspecific competition for food in the European grapevine moth Lobesia botrana.
2014
AbstractEffective pest management with lower amounts of pesticides relies on accurate prediction of insect pest growth rates. Knowledge of the factors governing this trait and the resulting fitness of individuals is thus necessary to refine predictions and make suitable decisions in crop protection. The European grapevine moth, Lobesia botrana, the major pest of grapes in Europe, is responsible for huge economic losses. Larvae very rarely leave the grape bunch on which they were oviposited and thus cannot avoid intraspecific competition. In this study, we determined the impact of intraspecific competition during the larval stage on development and adult fitness in this species. This was tes…
Phytoplankton assemblages respond differently to climate warming and eutrophication : A case study from Pyhäjärvi and Taihu
2016
Abstract Long-term monitoring data from two lakes located at different latitudes were used to test the hypothesis that phytoplankton communities respond differently to environmental changes (e.g., global warming and anthropogenic activities, mainly eutrophication). Lake Pyhajarvi (temperate area) and Lake Taihu (subtropical area) are both shallow and productive lakes. Presence/absence data indicated that phytoplankton taxa present did not change significantly in the two lakes over the last two decades. However, biomass data showed that dominance relationships of species changed in both lakes. Results of assemblage ordination indicated that climate change played a vital role in mediating phy…
The preference and costs of sleeping under light at night in forest and urban great tits
2019
Artificial light at night (ALAN) is an increasing phenomenon associated with worldwide urbanization. In birds, broad-spectrum white ALAN can have disruptive effects on activity patterns, metabolism, stress response and immune function. There has been growing research on whether the use of alternative light spectra can reduce these negative effects, but surprisingly, there has been no study to determine which light spectrum birds prefer. To test such a preference, we gave urban and forest great tits (Parus major) the choice where to roost using pairwise combinations of darkness, white light or green dim light at night (1.5 lux). Birds preferred to sleep under artificial light instead of dar…
Cyclical and stochastic thermal variability affects survival and growth in brook trout
2019
Directional changes in temperature have well-documented effects on ectotherms, yet few studies have explored how increased thermal variability (a concomitant of climate change) might affect individual fitness. Using a common-garden experimental protocol, we investigated how bidirectional temperature change can affect survival and growth of brook trout (Salvelinus fontinalis) and whether the survival and growth responses differ between two populations, using four thermal-variability treatments (mean: 10 °C; range: 7–13 °C): (i) constancy; (ii) cyclical fluctuations every two days; (iii) low stochasticity (random changes every 2 days); (iv) high stochasticity (random changes daily). Recently …
The evolution of sperm morphometry in pheasants
2007
7 pages; International audience; Post-copulatory sexual selection is thought to be a potent evolutionary force driving the diversification of sperm shape and function across species. In birds, insemination and fertilization are separated in time and sperm storage increases the duration of sperm-female interaction and hence the opportunity for sperm competition and cryptic female choice. We performed a comparative study of 24 pheasant species (Phasianidae, Galliformes) to establish the relative importance of sperm competition and the duration of sperm storage for the evolution of sperm morphometry (i.e. size of different sperm traits). We found that sperm size traits were negatively associat…