6,356 research outputs found
New and little known Cerambycidae (Coleoptera Chrysomeloidea) from Pantelleria Island (Sicily Channel, Italy)
Cerambycidae (Coleoptera Chrysomeloidea) nuovi e poco conosciuti dell’isola di Pantelleria (Cana-le di Sicilia, Italia).In questa nota riportiamo nuovi dati di due specie di Cerambycidae raccolte sul-l’isola di Pantelleria (Canale di Sicilia, Italia). In particolare, la presenza di Trichoferus holosericeus(Rossi, 1790) è confermata e Cephalocrius syriacus(Reitter, 1895) è riportato come nuovo recor
Trophic and spatial complementarity on seed dispersal services by birds, wild mammals, and cattle in a Mediterranean woodland pasture
Most earth surfaces have undergone intensive land-use changes, creating habitat mosaics. Seed dispersal by animals is a crucial process in such mosaics, but community-wide studies comparing the functional complementarity and response to man-imposed habitat heterogeneity are rare. Here, we investigate the trophic and spatial seed dispersal networks underpinning a strong, woody vegetation expansion over a pastureland inside the largest forest remnant in western Sicily, Italy. Over two fruiting seasons, we surveyed transects in three distinct biomes within our study area: forest, pastureland, and unpaved road. In total, we collected 659 feces and tested for differences in defecation patterns and seed rain density of birds, wild mammals, and cattle. We also tested the degree of trophic and spatial specialization and modularity using a network approach. Overall, birds dispersed 1208 seeds/ha of nine plant species, including six exclusive. Mammals dispersed 679 seeds/ha from four wild species, three of which also dispersed by birds, and 38 seeds/ha of three cultivated species. In turn, mammals dispersed exclusively the seeds of wild pear (Pyrus amygdaliformis), the most abundant tree in the woodland pasture. Cattle only dispersed wild pear, but accounting for 56% of the dispersed seeds. Seed rain densities were significantly higher in woodland pastures than in forests. However, almost of half the seeds dispersed by cattle and red fox were deposited on unpaved roads. While both trophic and spatial networks were more specialized than expected, we did detect distinct modules. Our study demonstrated the magnitude of the effects of man-made habitat heterogeneity on seed dispersal services, giving baseline information for restoration programs as well as high nature value pastureland management strategies
Priorities and gaps in Mediterranean bat research evidence: a systematic review for the early twenty-first century
Bat conservation is one of the top global concerns for research today; however, conservation efforts
may still be limited and impotent due to inadequacy and scarcity of data. Hence, identifying
research trends, threatening factors, species status, and geographical priorities is an essential tool
for future conservation, protection and prioritization. Here we conduct a comprehensive systematic
review to identify current research priorities, trends, general patterns and gaps regarding Mediterranean
bat researches. A total of 97 studies were found in the years spanning between 2000 and
2021. There were 18 studies with sufficient data for qualitative statistical analysis to investigate the
impact of different habitat and land managements on bat activity and species richness. A yearly average
of 4.6 articles were published, with a slight increase post-2010. Out of 61 identified species,
21% of species are threatened. Approximately, 65% of studieswere conducted in the Mediterranean
European region, primarily in Spain (29%), Italy (15.5%), and Portugal (10.3%), largely focusing
on forest habitats (38%). We found that Mediterranean bat species received uneven research attention,
with only 15% of research allocated to threatened bats. Around half of the studies focused
on the following bat species; Pipistrellus pipistrellus, Pipistrellus kuhlii, Miniopterus schreibersii,
Rhinolophus hipposideros, Pipistrellus pygmaeus, Myotis myotis, and Rhinolophus ferrumequinum.
Our statistical analysis showed that riparian areas had higher bat activity than forest and agriculture
areas. Bat population responded positively to forest management and organic agriculture practices.
To reduce future research misalignment between current local research status and future global
conservation priorities, we strongly advocate for urgent and additional collaborative efforts to target
under-researched species and areas. Finally, our review will provide a general overview and an
objective synthesis on the current status of bats in the Mediterranean and serve as a baseline for
further effective research
Can Moduli Fields parametrize the Cosmological Constant?
We study the cosmological evolution of string/M moduli fields T. We use
T-duality to fix the potential and show that the superpotential W is a function
of the duality invariant function j(T) only. If W is given as a finite
polynomial of j then the moduli fields {\it do not} give an accelerating
universe, i.e. they {\it cannot} be used as quintessence. Furthermore, at T >>1
the potential is given by a double exponential potential V \simeq e^{-a
e^{\sqrt{2} T}} leading to a fast decaying behaviour at large times. For moduli
potentials with a finite v.e.v. of T the energy density redshift is model
dependent but if T has a finite mass, m < \infty, then the moduli energy
density redshifts faster or equal to matter. Only if the moduli mass is
infinite can the moduli energy density dominate the universe independently of
the initial conditions.Comment: 13 pages, LaTeX, 3 postscript figure
Correlações canônicas entre características morfológicas, físicas e bromatológicas do capim Xaraés sob pastejo rotativo
In forage evaluation experiments, the assessment of adaptive and productive characteristics of genotypes is generally prioritized over qualitative responses such as nutritive value and voluntary intake. Methods that are capable of characterizing forage quality through the physical resistance to degradation have been proposed, including grinding resistance and shearing resistance. Canonical correlations establish a multivariate approach associating multiple variables depicting inter-relations studies between groups of dependent and independent variables. The objective of this research was to assess the degree of association among groups of quality-related responses of grazed Xaraés palisadegrass forage using canonical correlations among morphological, chemical and physical characteristics of forage samples. Only the first canonical pair was significant in the correlation between the morphological and physical variables. Between morphological and chemical variables, none of the canonical pairs were significant. In the canonical correlation between physical and chemical variables, the only significant canonical pair was the first, where forage with lower shearing resistance of leaves and stems, had higher concentration of crude protein in leaves and whole forage, lower concentration of neutral detergent fiber in leaves and whole forage, and higher digestibility of leaves and stems. The study of canonical correlations allowed to explain the relation between groups of qualitative variables of grazed Xaraés palisadegrass, and is highly significant between morphological and physical variables, and between physical than chemical variables.Em experimentos de avaliação de forrageiras muitas vezes são priorizadas as análises de adaptação e produtividade e posteriormente parâmetros de valor nutritivo e consumo. Através de estudos para melhor caracterizar a qualidade de forrageiras por meio de sua resistência física foram propostas técnicas tais como a resistência à moagem e a resistência ao cisalhamento. Análise de correlação canônica é uma abordagem estatística sobre múltiplas variáveis que facilita o estudo de inter-relações entre grupos de variáveis dependentes e independentes. O objetivo desta pesquisa foi avaliar o grau de associação entre grupos de respostas qualitativas da forragem do capim Xaraés sob pastejo utilizando correlações canônicas entre características morfológicas, bromatológicas e físicas de amostras de forragem. Apenas o primeiro par canônico foi significativo na correlação entre variáveis morfológicas e físicas. Na análise de correlação canônica entre variáveis morfológicas e bromatológicas, nenhum dos pares canônicos foi significativo. Na correlação canônica entre variáveis físicas e bromatológicas, apenas o primeiro par foi significativo, onde forragem com menor resistência ao cisalhamento de colmos e folhas, possui maior concentração de proteína bruta (PB) nas folhas e na forragem íntegra, menores concentrações de fibra em detergente neutro (FDN) nas folhas e na forragem íntegra e alta digestibilidade de folhas e colmos. O estudo de correlações canônicas permitiu explicar a relação entre grupos de variáveis qualitativas do capim Xaraés sob pastejo, e é significativa entre variáveis morfológicas e físicas, e entre físicas versus bromatológicas
Correlações canônicas entre características morfológicas, físicas e bromatológicas do capim Xaraés sob pastejo rotativo
In forage evaluation experiments, the assessment of adaptive and productive characteristics of genotypes is generally prioritized over qualitative responses such as nutritive value and voluntary intake. Methods that are capable of characterizing forage quality through the physical resistance to degradation have been proposed, including grinding resistance and shearing resistance. Canonical correlations establish a multivariate approach associating multiple variables depicting inter-relations studies between groups of dependent and independent variables. The objective of this research was to assess the degree of association among groups of quality-related responses of grazed Xaraés palisadegrass forage using canonical correlations among morphological, chemical and physical characteristics of forage samples. Only the first canonical pair was significant in the correlation between the morphological and physical variables. Between morphological and chemical variables, none of the canonical pairs were significant. In the canonical correlation between physical and chemical variables, the only significant canonical pair was the first, where forage with lower shearing resistance of leaves and stems, had higher concentration of crude protein in leaves and whole forage, lower concentration of neutral detergent fiber in leaves and whole forage, and higher digestibility of leaves and stems. The study of canonical correlations allowed to explain the relation between groups of qualitative variables of grazed Xaraés palisadegrass, and is highly significant between morphological and physical variables, and between physical than chemical variables.Em experimentos de avaliação de forrageiras muitas vezes são priorizadas as análises de adaptação e produtividade e posteriormente parâmetros de valor nutritivo e consumo. Através de estudos para melhor caracterizar a qualidade de forrageiras por meio de sua resistência física foram propostas técnicas tais como a resistência à moagem e a resistência ao cisalhamento. Análise de correlação canônica é uma abordagem estatística sobre múltiplas variáveis que facilita o estudo de inter-relações entre grupos de variáveis dependentes e independentes. O objetivo desta pesquisa foi avaliar o grau de associação entre grupos de respostas qualitativas da forragem do capim Xaraés sob pastejo utilizando correlações canônicas entre características morfológicas, bromatológicas e físicas de amostras de forragem. Apenas o primeiro par canônico foi significativo na correlação entre variáveis morfológicas e físicas. Na análise de correlação canônica entre variáveis morfológicas e bromatológicas, nenhum dos pares canônicos foi significativo. Na correlação canônica entre variáveis físicas e bromatológicas, apenas o primeiro par foi significativo, onde forragem com menor resistência ao cisalhamento de colmos e folhas, possui maior concentração de proteína bruta (PB) nas folhas e na forragem íntegra, menores concentrações de fibra em detergente neutro (FDN) nas folhas e na forragem íntegra e alta digestibilidade de folhas e colmos. O estudo de correlações canônicas permitiu explicar a relação entre grupos de variáveis qualitativas do capim Xaraés sob pastejo, e é significativa entre variáveis morfológicas e físicas, e entre físicas versus bromatológicas
The Role of Almond-Leaved Pear Pyrus spinosa Forssk. in Mediterranean Pasturelands Carbon Storage and Woodlands Restoration
A large portion of the Mediterranean basin suffers from a lack of organic carbon in the soil and low woody cover percentages, resulting in a very high risk of desertification. In such conditions, knowing the effects on below and above ground carbon sequestration of pioneer woody species is of great importance, although barely assessed at the individual level. In this study, we first investigated whether almond-leaved pear (Pyrus spinosa) individuals influence soil organic carbon (SOC) concentration and stock in comparison with surrounding pasturelands inside a natural reserve in Sicily, Italy. Second, we evaluated inter individual variability on such storage, testing the effects of plant height, basal diameter, canopy cover and tree structure (single or multiple stems). Soils under pear presented, on average, a significantly higher SOC than pasturelands (3.86% and 3.16%, respectively) as well as a lower bulk density (1.09 and 1.28 g cm−3, respectively). Due to a lower soil compaction, SOC stocks (130.3 and 113.9 Mg ha−1, respectively) did not differ significantly. Below and aboveground biomass carbon accounted for a small fraction of carbon stock, while neither pear structure, age nor tree structure significantly influenced SOC concentration and SOC stock. Despite the need of further investigations, our results indicate that pear may represent an excellent tree species to improve carbon storage, both while triggering the restoration of Mediterranean woodlands or increasing biodiversity in pasturelands and agroforestry systems, that, indeed, can hold high SOC if well managed
Vegetation dynamics within afforested coastal areas: regeneration by native species or invasion by alien species?
During the last century, massive reforestation projects along the dunes of the southern Sicily have been carried out. Such interventions, far from being in line with the current trends of close-to-nature silviculture, are, however, particularly interesting to assess the vegetation dynamics in afforestation areas. Furthermore, these kind of interventions may determine two opposite effects, that is renaturalization by native woody species or invasion by alien species. Acacia spp. are among the most widespread and prominent invaders within Mediterranean-climate areas, where they have already shown the capability to deeply change the characters and the functioning of native ecosystems. For instance, Acacia longifolia (Andrews) Willd. may successfully invade the understory of pine forests, causing the alteration of the water balance and carbon storage of the whole forest ecosystem. In Sicily, especially in the last decades, Acacia saligna started to abundantly regenerate in many natural and semi-natural areas, with a stark preference for dune and coastal afforested sites. The nature reserve \u201cFoce del Fiume Platani\u201d represents an excellent case study in this respect
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