Search results for "010601 ecology"
showing 10 items of 69 documents
Density and reproductive characteristics of female brown bears in the Cantabrian Mountains, NW Spain
2018
Here we present annual nearest-neighbour distances (as a proxy of density) between females with cubs-of-the-year (hereafter FCOY) and reproductive characteristics of brown bears Ursus arctos in the Cantabrian Mountains (NW Spain), from 1989 to 2017. FCOY nearest-neighbour distances and reproduction parameters of 19 focal females followed over several consecutive years (from 2004 to 2017) were obtained from bears inhabiting the western sector of the Cantabrian Mountains, where most of the bear population resides. In contrast, general reproductive characteristics were studied in the whole Cantabrian Mountains (western and eastern sectors together) on a sample of 362 litter sizes and 695 cubs.…
Coexistence and resource competition.
2000
How large numbers of species coexist on a seemingly limited number of different resources is a classic problem in ecology1, and attempts have been made to solve it experimentally. But we are not convinced that Huisman and Weissing's2 proposal to add non-stationary dynamics in species abundance to the list of possible explanations offers any new insight into this biodiversity enigma.
Paisaje y nacionalismo en el primer franquismo
2016
Assuming the theoretical idea widely developed by Human Geography that landscapes are cultural constructions with the capacity to become symbolic elements within nationalist discourses, this article explores the context of early Francoism. The aim of these pages is to analyze landscape sensibility as well as the landscape idea developed by the francoist nationalist discourse by trying to draw out three inherent elements in it: first of all, following Oliver Zimmer’s work, the nationalization of nature, this is to say, the consideration that nature expresses the community’s myths, events or memories; secondly, the naturalisation of the nation, that projects upon landscapes the capacity to de…
Future Cities. Urban Transformation and Sustainable Development
2016
The complex urban reality, in continuous evolution, are characterized by buildings, facilities, equipment, human capital, social capital and the ability to create sustainable economic development. Today, urban planning is called to respond to the new needs of the community, for this reason it is necessary to avoid the mistakes made in the past and think of a plan to be adapted to the change. All this is possible through the implementation of participatory strategic actions which ensure high levels of quality of life as well as responsible management of land resources. This outlines the concept of sustainable development and resilient cities, forcefully entered in today’s urban paradigm, bec…
Managing for resilience: an information theory-based approach to assessing ecosystems
2016
Ecosystems are complex and multivariate; hence, methods to assess the dynamics of ecosystems should have the capacity to evaluate multiple indicators simultaneously. Most research on identifying leading indicators of regime shifts has focused on univariate methods and simple models which have limited utility when evaluating real ecosystems, particularly because drivers are often unknown. We discuss some common univariate and multivariate approaches for detecting critical transitions in ecosystems and demonstrate their capabilities via case studies. Synthesis and applications. We illustrate the utility of an information theory-based index for assessing ecosystem dynamics. Trends in this inde…
Species loss leads to community closure
2008
Global extinction of a species is sadly irreversible. At a local scale, however, extinctions may be followed by re-invasion. We here show that this is not necessarily the case and that an ecological community may close its doors for re-invasion of species lost from it. Previous studies of how communities are assembled have shown that there may be rules for that process and that limitations are set to the order by which species are introduced and put together. Instead of focusing on the assembly process we randomly generated simple competitive model communities that were stable and allowed for two to 10 coexisting species. When a randomly selected single species was removed from the communit…
Algae in urban water bodies - control of growth and use as a biomas
2018
Enhancing the ecology security of Ukraine and other developing countries is predetermined by the environmental problems of cities. It prompts studies on the contamination of city's and adjacent water bodies. The control of blue-green algae distribution and the use of its biomass for production of the biofuels, energy, oils, medicine, etc. is one of the contributing factors to the well-balanced development of infrastructure of cities. The intensity of the processes of eutrophication and the species composition of the algae, which cause algal blooming, was investigated based on data of the Vorskla River in Poltava city (Ukraine). Relevant methods, statistical data of Ukrainian Environmental S…
Quantitative Genetics of the Aging of Reproductive Traits in the Houbara Bustard
2015
International audience; Do all traits within an organism age for the same reason? Evolutionary theories of aging share a common assumption: the strength of natural selection declines with age. A corollary is that additive genetic variance should increase with age. However, not all senescent traits display such increases suggesting that other mechanisms may be at play. Using longitudinal data collected from more than 5400 houbara bustards (Chlamydotis undulata) with an exhaustive recorded pedigree, we investigated the genetics of aging in one female reproductive trait (egg production) and three male reproductive traits (courtship display rate, ejaculate size and sperm viability), that displa…
Conditions requisite for stability of polymorphic balance in Philaenus spumarius (L.) (Homoptera)
1990
Frequencies of colour morphs were recorded in 1969–74 in 5 island populations of Philaenus spumarius. The polymorphic balance was accurately maintained in three of them, but less constantly in the other two. One of the latter populations experienced a great fluctuation in size, and this was accompanied by a profound alteration in morph frequencies.
FLUCTUATING TEMPERATURE LEADS TO EVOLUTION OF THERMAL GENERALISM AND PREADAPTATION TO NOVEL ENVIRONMENTS
2013
Environmental fluctuations can select for generalism, which is also hypothesized to increase organisms' ability to invade novel environments. Here, we show that across a range of temperatures, opportunistic bacterial pathogen Serratia marcescens that evolved in fluctuating temperature (daily variation between 24°C and 38°C, mean 31°C) outperforms the strains that evolved in constant temperature (31°C). The growth advantage was also evident in novel environments in the presence of parasitic viruses and predatory protozoans, but less clear in the presence of stressful chemicals. Adaptation to fluctuating temperature also led to reduced virulence in Drosophila melanogaster host, which suggests…