Search results for " land"

Wole Soyinka: Due Poesie

2008

Durante l'undicesima edizione del Festivaletteratura di Mantova, nel settembre 2007, Wole Soyinka, insieme alla studiosa e traduttrice Alessandra Di Maio, ha ripercorso la sua carriera poetica, spiegandone svolte e sviluppi. In questa sede si riportano due delle sue poesie più note in traduzione -- "Conversazione telefonica" e "I figli di questa terra" -- che coprono idealmente l'arco della sua produzione poetica, dalla gioventù all'eta matura.

2015

Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the extant bird species. Leaf warblers are a speciose Old-World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well-resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independe…

Stopover strategies in birds: a review of methods for estimating stopover length

1999

This study categorizes and reviews methods used to estimate stopover length in migratory birds. Stopover length is an important variable in analysing migration strategies. The analysis of the stopover pattern of migratory birds typically attempts to investigate variability in the number of stopovers and in the length of time spent at stopover sites in relation to species, age, sex and body condition. Although the number of capture-recapture studies analysing stopover length has increased substantially, most are analysed using the simple last-first capture method which gives biased estimates. The use of mathematical models to calculate stopover length is uncommon. Most researchers assume hom…

Carbon use efficiency variability from MODIS data

2017

[EN] Carbon use efficiency (CUE) describes how efficiently plants incorporate the carbon fixed during photosynthesis into biomass gain and can be calculated as the ratio between net primary production (NPP) and gross primary production (GPP). In this work, annual CUE has been obtained from annual GPP and NPP MODIS products for the peninsular Spain study area throughout eight years. CUE is spatially and temporally analyzed in terms of the vegetation type and annual precipitation and annual average air temperature. Results show that dense vegetation areas with moderate to high levels of precipitation present lower CUE values, whereas more arid areas present the highest CUE values. However, th…

Optimal contract length for biodiversity conservation under conservation budget constraint

2014

We examine the optimal length of a contract period in a conservation program with payments for ecosystem services aiming at protecting biodiversity on privately owned forests. The government chooses the number of stands and the length of contracts so as to maximize biodiversity benefits under a binding conservation budget. We examine the implication of two alternative budgets: a separate budget for each period (periodic budget) or one budget that to be used in all periods (intertemporal budget). The impact of the budget type shows up in the fact that with intertemporal budget choice set is larger and more high quality stands are available for contracting. Based on theoretical characterizati…

Influence of plant traits, soil microbial properties, and abiotic parameters on nitrogen turnover of grassland ecosystems

2016

International audience; Although it is known that multiple interactions among plant functional traits, microbial properties , and abiotic soil parameters influence the nutrient turnover, the relative contribution of each of these groups of variables is poorly understood. We manipulated grassland plant functional composition and soil nitrogen (N) availability in a multisite mesocosm experiment to quantify their relative effects on soil N turnover. Overall, root traits, arbuscular mycorrhizal colonization, denitrification potential, as well as N availability and water availability, best explained the variation in measured ecosystem properties, especially the trade-off between nutrient sequest…

Diversity and Evolution of the Phenazine Biosynthesis Pathway

2010

ABSTRACT Phenazines are versatile secondary metabolites of bacterial origin that function in biological control of plant pathogens and contribute to the ecological fitness and pathogenicity of the producing strains. In this study, we employed a collection of 94 strains having various geographic, environmental, and clinical origins to study the distribution and evolution of phenazine genes in members of the genera Pseudomonas , Burkholderia , Pectobacterium , Brevibacterium , and Streptomyces . Our results confirmed the diversity of phenazine producers and revealed that most of them appear to be soil-dwelling and/or plant-associated species. Genome analyses and comparisons of phylogenies inf…

Landscape Dynamics and Cultural Contacts in the Territory of Himera in the Archaic Period

2022

In central-northern Sicily, the watershed area between the northern and southern Imera and Platani rivers has already been recognized for years as a pivotal area in relations between the different areas of the island, both in reference to the political and economic projections of the colonial poleis , especially between Himera, Akragas, both in reference to economic relations and cultural contacts with indigenous communities. This area is very crucial context of encounter and confrontation between communities, in which complex systems of territorial articulation can be grasped. The position of the settlements along the basins of the two Himera highlights a close connection in terms of inter…

Regulating Internet Trade in CITES Species

2013

International trade in species that are or may be endangered by collection from the wild is regulated under the Convention on International Trade in Endangered Species of wild fauna and flora (CITES) for 176 member States (Parties). Internet commerce is a relatively new route for such trade. In 2007, the CITES Secretariat asked Parties to collect information on internet wildlife trade and report problems and implemented regulations. The reports indicated it was difficult to even approximate the influence of e-commerce on CITES-listed species (CITES Secretariat 2009). We report a case study in which we quantified international transactions over an internet auction site of CITES-listed cacti …

Les phénols de la lignine et le 13C, traceurs de l'origine des matières organiques du sol

2001

Abstract In spodosols of Gascony (France), conversion of maritime pine stands into maize cropping leads to an incorporation of maize organic matter, which changed the isotopic (δ13C) and phenolic signature in A and L horizons of soil. Hydrolysis of phenol lignin in forests and cultivated soils showed the predominance of vanillic units under forest and the early but moderate incorporation of cinnamic acids. Incorporation of syringic units appeared higher, related to a large maize production of stable syringic phenols. Syringic units represented a long-term marker of maize inputs in soils, whereas vanillic units revealed the degradation of forest organic matter.