Search results for "Pinu"

I pini monumentali della Fossa della Garofala.

2016

In città è difficile rinvenire alberi monumentali a causa delle negative interazioni tra le attività antropiche e la vegetazione. Lo sviluppo delle piante arboree assume un aspetto notevolmente differente rispetto a quello che si potrebbe avere in un ecosistema naturale. In una città come Palermo in cui la forte espansione urbanistica ha sottratto aree verdi rimangono solo alcuni lembi sopravvissuti alla cementificazione. Un caso particolare è rappresentato dalla Fossa della Garofala che, pur essendo inclusa all’interno del tessuto urbano, ha elevati caratteri di naturalità. Ciò è dovuto alla storia passata e recente, l’area acquisita dall’Università di Palermo nel 1950, grazie all’apposizi…

Primi dati sugli alberi monumentali di Pantelleria

2016

Poche o nulla sono le informazioni sugli alberi monumentali delle piccole isole che circondano la Sicilia. Ciò è dovuto innanzitutto alla rarità di alberi definibili monumentali, le piccole isole hanno subito infatti una trasformazione ancora più profonda della Sicilia, ma anche ad un difetto di conoscenza. Il nostro vuole essere un primo contributo alla conoscenza degli alberi monumentali nell’isola di Pantelleria. Gli alberi censiti appartengono a due specie, il pino marittimo (Pinus pinaster subsp. hamiltonii) e il leccio (Quercus ilex). In realtà nel caso del pino marittimo possiamo parlare di un “popolamento monumentale” corrispondente alla pineta a pino marittimo presso la località Mo…

Pine stand density influences the regeneration of Acacia saligna (Labill.) H.L.Wendl. and native woody species in a mediterranean coastal pine planta…

2018

Mediterranean plantations are the most suitable areas to assess vegetation dynamics and competitive interactions between native and exotic woody species. Our research was carried out in a coastal pine plantation (Sicily) where renaturalization by native species (Pistacia lentiscus L. and Olea europaea var. sylvestris) and invasion by Acacia saligna (Labill.) H.L.Wendl. simultaneously occur. The regeneration pattern of woody species in the pine understory was evaluated in six experimental plots along a stand density gradient, from 200 to approximately 700 pines per hectare. Both pine stand density and regeneration by native species had a significant negative relationship with Acacia natural …

Nodular Lesion in Cheek With a Hair Tuft

2017

Trichostasis spinulosa is a rarely diagnosed disorder of the pilosebaceous unit, characterized by retention of telogen hairs within the dilated follicles. A hair tuft can be seen protruding from the follicles. We present a case of trichostasis spinulosa associated with intradermal melanocytic nevi, where dermoscopy helps to identify this entity.

Slāpekļu vakanču centru T1 relaksācijas laika pētījumi divos ar zemās enerģijas elektroniem apstarotos dimantu paraugos

2017

Slāpekļa vakances centrus dimantos var izmantot, lai noteiktu materiālu iekšējo spriegumu, temperatūru un elektrisko lauku mikroskopiskos telpas apvidos, kā arī, lai novērotu zemu koncentrāciju paramagnetiskās molekulas un jonus, kuru magnētiskais lauks samazina T1 relaksācijas laiku. Slāpekļa vakances dimantos rada ar apstarošanu, parasti ar elektroniem vai citām daļiņām, kuru enerģija ir ap dažiem megaelektronvoltiem. Pētījumā tika izveidoti dimanta paraugi, izmantojot zemas enerģijas elektronus ar transmisijas elektronu mikroskopu, kas ļauj veidot punktveida struktūras dimantā. Pētījumā divos paraugos T1 laika mērījumi atšķirās. Šajā bakalaura darbā autors salīdzināja divus dažādus diman…

Pinares y enebrales. El paisaje solutrense en Iberia

2013

Se presentan estudios antracológicos de yacimientos de la península Ibérica con el objetivo de conocer la flora durante el Solutrense y, a partir de ella, las condiciones termoclimáticas y ombroclimáticas. Con los datos publicados e inéditos se demuestra que los refugios de las especies más cálidas están al sur del paralelo 40º N. La flora identificada en los carbones se puede agrupar en cuatro categorías: criófilas, termófilas, matorral y ribera. Se observa un gradiente latitudinal de la distribución de los marcadores más térmicos como Pinus pinea, Rosmarinus officinalis, mientras que los pinos criófilos están distribuido por todas las regiones. Se propone la identificación botánica de los…

Le specie alloctone invasive in Sicilia: caratterizzazione del fenomeno, strategie di colonizzazione e possibili strategie di contrasto

2014

Adaptive radiation along a thermal gradient: preliminary results of habitat use and respiration rate divergence among whitefish morphs.

2014

Adaptive radiation is considered an important mechanism for the development of new species, but very little is known about the role of thermal adaptation during this process. Such adaptation should be especially important in poikilothermic animals that are often subjected to pronounced seasonal temperature variation that directly affects metabolic function. We conducted a preliminary study of individual lifetime thermal habitat use and respiration rates of four whitefish (Coregonus lavaretus (L.)) morphs (two pelagic, one littoral and one profundal) using stable carbon and oxygen isotope values of otolith carbonate. These morphs, two of which utilized pelagic habitats, one littoral and one …

Nest modifications by the acorn ant Temnothorax crassispinus (Hymenoptera: Formicidae)

2019

Many ant species construct nests and during the process considerably influence the environment such as by changing soil structure and creating new habitat for other species. However, other ant species dwell in ready-for-use cavities. Ants of the genus Temnothorax inhabit small cavities such as acorns and under rocks, but under natural conditions, good nest sites are limited resources. During field and laboratory experiments, I studied how the acorn ant Temnothorax crassispinus (Karawajew, 1926) modifies nesting sites. Temnothorax crassispinus is a forest species, which typically lives in cavities in fallen twigs and acorns; colonies usually number from a few dozen to about 200 workers. Alth…

High winter survival rate of acorn ants inside artificial nest sites (Hymenoptera: Formicidae)

2022

Although most species of ants overwinter underground to avoid low temperatures, the acorn ants of the genus Temnothorax remain in nests situated at ground level. During a field experiment, I studied the winter mortality of acorn ants in nest sites situated aboveground, as well as in sites experimentally buried in the soil. Despite the low air temperatures (even reaching –19°C, recorded 1.5 m above the ground), the survivorship was very high: all of the 18 queens used in the experiment survived, while the survival rate of workers was 61.9-100%, and for most colonies it exceeded 95%. The rate of survival in the nest sites aboveground and those experimentally buried in the soil was similar. Su…