293 research outputs found
Effects of traditional coppice practices and microsite conditions on tree health in a European beech forest at its southernmost range
European beech (Fagus sylvatica) grows at the southern limit of its range in the mountain-Mediterranean vegetation belt up to the timberline. The southernmost beech forests of Sicily (southern Italy) show peculiar ecological, structural and silvicultural characteristics, growing in fragmented and isolated stands near the timberline and in topographically marginal unfavorable habitats. Past silvicultural practices increased the heterogeneity of stand structure at these sites. We compared stand structural characteristics and tree health in coppice-cut and control beech stands with respect to the local topographic gradient (bottom, slope and ridge) and canopy cover (clearing/border vs. interior trees). Our results clearly showed a correlation between declining tree health (crown and bark damage, higher percentage of dead trees and lower seedling density) and recent coppice-cuts, poor (marginal) site quality (on ridges and slopes) and reduced canopy cover (in clearing/border trees). The decrease of tree health indicate an increasing threat to the long-term viability of beech stands facing multiple environmental stress factors (such as those related to southern latitude and topographic position). Declining tree health in the control plots also supports this hypothesis. We concluded that traditional forest management practices, such as coppice-cuts applied regardless to the specific microenvironmental conditions, may pose a risk to beech forest health at the southernmost edge of the species’ range
Popolamenti marginali di faggio e cambiamenti climatici: criticità dell’applicazione di pratiche colturali classici in ambiente mediterraneo (Sicilia)
Il faggio (Fagus sylvatica) è tra le specie forestali più importanti d’Europa per distribuzione, selvicoltura, rilevanza paesaggistica. Il faggio in Sicilia raggiunge il limite meridionale del proprio areale, nonché le quote altitudinali più elevate in Europa (timberline intorno a 2000 s.l.m.), localizzandosi sui Monti Nebrodi, Madonie ed Etna. La maggior parte di questi soprassuoli è stata tradizionalmente governata a ceduo semplice matricinato, seppur raramente all’interno di un quadro di interventi pianificati di lungo periodo, e molti popolamenti recentemente hanno subito primi interventi di avviamento alla conversione a fustaia. L’assetto attuale di questi soprassuoli è tuttavia destinato a cambiare nell’immediato futuro non solo per l’opera dell’uomo, ma soprattutto in vista dei probabili scenari del cambiamento climatico, particolarmente severi nelle loro previsioni per questi contesti di margine. Il presente lavoro è volto all’individuazione dei principali elementi di vulnerabilità , prendendo in esame alcuni soprassuoli particolarmente rappresentativi dei Monti Madonie, poiché essi presentano sintomi di sofferenza e segni di disseccamento e moria, probabilmente imputabili, oltre che ai mutamenti climatici in atto, a interventi di taglio di diversa entità , dalla dubbia finalità . Oltre ai consueti rilievi selvicolturali e dendro-auxometrici, sono state condotte indagini accurate sulla struttura dei popolamenti, tramite 4 aree di saggio permanenti in corrispondenza di aree sottoposte a taglio in epoche diverse e per 2 di queste sono state identificate delle aree testimone. Una parte fondamentale dello studio ha riguardato il rilievo dell’entità dei danni osservati a carico delle chiome e delle scottature dei fusti e delle principali branche delle singole ceppaie. L’analisi della struttura è stata condotta tramite l’applicazione di numerosi indici (Clark-Evans, Winkelmass, Shannon, Latham) nonché osservazioni scaturite dalla rappresentazione spaziale delle coperture analizzate, al fine di valutare i danni riscontrati rispetto alle mutate condizioni di illuminazione delle chiome delle singole ceppaie, generate dagli interventi di taglio. L’analisi comparativa dei risultati mostra chiaramente come gli interventi intensi di diradamento recentemente eseguiti abbiano generato una elevata incidenza di danni diffusi sulle diverse parti del soprassuolo, con effetti anche estremi di moria delle ceppaie. L’effetto negativo delle eccessive scoperture causato dagli interventi di taglio si è manifestato con severità sulle piante di faggio localizzate in prossimità delle radure e delle interruzioni della copertura. In conclusione vengono messe in evidenza le criticità delle pratiche selvicolturali applicate ai soprassuoli di faggio in tali contesti limite e, conseguentemente, l’accelerazione impressa ad una probabile dinamica in atto sotto gli effetti dei noti cambiamenti climatici
POPOLAMENTI MARGINALI DI FAGGIO E CAMBIAMENTI CLIMATICI IN SICILIA: CRITICITÀ ED EFFETTI DELL’APPLICAZIONE DI PRATICHE SELVICOLTURALI TRADIZIONALI NON-SOSTENIBILI AL VARIARE DELLE CONDIZIONI MICRO-STAZIONALI
Il faggio (Fagus sylvatica) è una tipica specie medio-Europea; in Sicilia si rinvengono i boschi di faggio più
meridionali d’Europa. La marginalità ecologica di questi boschi è particolarmente evidente nei pattern frammentati
e isolati di questi soprassuoli, in prossimità del limite della vegetazione arborea e/o localizzati nelle
condizioni topografiche meno favorevoli. Nel presente lavoro si mettono a confronto i parametri dendrometricostrutturali
e lo stato di salute delle piante in soprassuoli delle Madonie, confrontando cedui di faggio recentemente
sottoposti a pratiche di taglio e aree di controllo non trattate da tempo. Inoltre, questi aspetti sono stati messi in
relazione con il gradiente topografico locale ed alla frammentazione della copertura.Sulla base delle condizioni
topografiche marginali (crinali, versanti) e della frammentazione della copertura (alberi al margine/radura), i
risultati mostrano chiaramente una forte riduzione dello stato di salute delle piante (maggiori danni alla corteccia
e alla chioma, una percentuale più alta di alberi morti, una minore densità di rinnovazione) correlate all’intervento
di taglio del ceduo. Il chiaro deperimento delle piante può determinare in futuro una minaccia crescente per
queste faggete multi-marginali (per latitudine, topografia e frammentazione della copertura). Inoltre, i risultati
ottenuti fanno ipotizzare che, anche se l’effetto degli interventi selvicolturali è evidente nei due gruppi a confronto
(aree tagliate e aree controllo), la riduzione dello stato di salute di queste piante sia ulteriormente accelerata dagli
effetti che il cambiamento climatico generale sta determinando in queste condizioni stazionali di marginalitÃ
ecologica. Il ridotto stato di salute delle piante anche nelle aree di controllo avvalora questa ipotesi.Marginal fragmented beech stands and climate change in Sicily:
effects of non-sustainable traditional silviculture practices in relation to micro-topographic gradient
In Sicily where the southernmost beech forests of Europe are located, beech stands show
peculiar ecological, characters. The ecological marginality of these forests is particularly evident
in the fragmented and isolated beech stands, near the timberline and/or located on less
favourable topographic conditions.
In this study we analyzed stand-structural parameters and tree health comparing recently
coppice felled beech stands and control plots. Additionally, these aspects have been related also
to the local topographic gradient and the cover fragmentation.
Results clearly show a pronounced tree health reduction (more crown and bark damages,
higher percentage of dead trees, lower seedling density) related to cut coppice, as far as to
marginal topographic condition (on ridges and slopes) and stand-cover fragmentation (in
clearing/border trees). The clear decreased tree health may lays an increasing future threat for
these multi-marginal (for latitude, topography and cover fragmentation) beech stands. In
addition, our results could also support the hypothesis that, although the silviculture effects
originated by the human actions is quite evident in the two compared groups (coppice-cut and
control), hastening the tree health reduction, a general climate change effect is going on these
marginal beech stands. The reduced tree health status also in control plots seems to show this way
Management of multiple pregnancy with an affected twin
Newborns from multiple pregnancies demonstrate a higher perinatal morbidity and mortality compared to singletons. Prematurity is more frequent in twins and therefore birth weight is significantly lower compared to singletons [1]. Thus, twins are more exposed to prema- turity related diseases (respiratory, cardiovascular, infec- tious, etc.) and to long-term complications [2]. It is very difficult to estimate the increased risk of neonatal mor- bidity related to twinning independently to the increased risk of prematurity. Prematurity is the main reason for most neonatal diseases in twins, but other variables may play a role. Fetal growth restriction [3] and congenital malformationsare major issues in offspring of multiple pregnancies. Specific risks vary according tozigosity (monozygotic >dizygotic) and kind (genetic, vascular, multifactorial, etc.) and site (systems and organs involved) of malformation. Accurate risk assessment strategies and adequate obstetrical-neonatological man- agement of multiple pregnancies may reduce the increasing need for neonatal intensive care and for health resources in the long-term follow-up that has been observed over the last decades.
Careful analysis of both twins for a pathological condi- tion is mandatory to address the most appropriate man- agement. Twin discordance for the presence of a severe pathological condition raises serious concern in terms of bioethical and psychological impact on the parents and medical staff[4]. Different management choices can be considered: termination of pregnancy, selective embryo reduction of the affected twin, anticipation of delivery or natural course of the pregnancy. Each choicehides difficult clinical and legal implications. Accurate clinical, laboratory and ultrasonographic evaluation together with pregnancy follow-up are essential for reaching the correct diagnosis and consider prognosis and therapeutic options [5]. The risk of intrauterine death and potential risks for the other twin and the mother must be taken into account. Some- times it is possible to wait until the natural end of preg- nancy and then provide suitable treatment to the affected twin. Other times, parents opt to terminate the pregnancy and loose both twins. A selective reduction (after accurate evaluation of placentation) of the affected twin only carries a high risk of complication for the healthy twin, especially in monochorionic pregnancies. In the late third trimester of pregnancy, the option of a preterm delivery can be con- sidered and may contribute to the increase of prematurity and prematurity related diseases in twins.
The management of multiple pregnancies is a very com- plex task for medical staff and requires parental support with adequate counselling and psychological help [6]
Predictive Factors of Abdominal Compartment Syndrome in Neonatal Age
In the pediatric population, abdominal compartment syndrome (ACS) is a known complication of abdominal wall defect repair. However, there are only few reports on ACS in newborns and only a proposal of critical intra-abdominal pressure value (IAP) in term newborns, absent in preterm newborns. Although the prevalent clinical sign is tense abdominal distension, it may be difficult to distinguish ACS from pathologies that will not require decompression. The purpose of this study was to identify predictors for ACS and therefore morbidity or mortality indicators. We reviewed newborns presenting with tense abdominal distension and end organ failure. Anamnestic, clinical, laboratory, and instrumental investigations were analyzed to extrapolate predictors. Outcomes were compared with a control group. The incidence of ACS in our neonatal intensive care unit was 5% in the overall population of babies, 16% in tracheal-ventilated newborns, and 57% in infants with abdominal wall defects. We found that, with onset of acidosis or high gastric residuals, the lactate values will be predictive for mortality. We can also suggest paying particular attention to high lactate values just at the onset of distension, in infants with more advanced gestational age, with previously surgical repair, to determine early surgical intervention independently of a specific IAP measurement
Congenital cytomegalovirus related intestinal malrotation: a case report
Background: Cytomegalovirus is the most common cause of congenital infection in the developed countries. Gastrointestinal involvement has been extensively described in both adult and paediatric immunocompromised patients but it is infrequent in congenital or perinatal CMV infection. Case presentation: We report on a case of coexistent congenital Cytomegalovirus infection with intestinal malrotation and positive intestinal Cytomegalovirus biopsy. At birth the neonate showed clinical and radiological evidence of intestinal obstruction. Meconium passed only after evacuative nursing procedures; stooling pattern was irregular; gastric residuals were bile-stained. Laparatomy revealed a complete intestinal malrotation and contextually gastrointestinal biopsy samples of the appendix confirmed the diagnosis of CMV gastrointestinal disease. Intravenous ganciclovir was initiated for 2 weeks, followed by oral valgancyclovir for 6 month. Conclusion: CMV-induced proinflammatory process may be responsible of the interruption of the normal development of the gut or could in turn lead to a disruption in the normal development of the gut potentiating the mechanism causing malrotation. We suggest the hypothesis that an inflammatory process induced by CMV congenital infection may be responsible, in the early gestation, of the intestinal end-organ disease, as the intestinal malrotation. CMV infection should always be excluded in full-term infants presenting with colonic stricture or malrotation
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