Learn More
Keywords: Climate change Drought effects Forest die-off Forest mortality Global patterns Tree mortality A B S T R A C T Greenhouse gas emissions have significantly altered global climate, and will continue to do so in the future. Increases in the frequency, duration, and/or severity of drought and heat stress associated with climate change could(More)
1 We analyse the factors controlling seedling establishment of Scots pine at its south-ernmost geographical limit (southern Spain), by monitoring emergence, survival and growth for up to 4 years in the microhabitats to which seeds are dispersed. Naturally established seedlings were monitored in two mountain ranges, and experimental sow-ings were performed(More)
Common techniques currently used for afforestation in the Mediterranean basin consider the pre-existing vegetation (mainly shrubs) as a source of competition for trees, and consequently it is generally eliminated before planting. Nevertheless, it has been demonstrated that woody plants can facilitate the establishment of understory seedlings in environments(More)
We introduce a new combinatorial dimension that gives a good approximation of the number of queries needed to learn in the exact learning model, no matter what set of queries is used. This new dimension generalizes previous dimensions providing upper and lower bounds for all sorts of queries, and not for just example-based queries as in previous works. Our(More)
The wide distribution of Scots pine (Pinus sylvestris L.) in Europe includes two relict populations in southern Spain (Sierra Nevada and Sierra de Baza), belonging to the subspecies nevadensis. These populations are isolated in high mountains, which tends to protect them from the attack of a severe defoliating Mediterranean pest, the pine processionary moth(More)
The impact of mammalian herbivory on Scots pine (Pinus sylvestris L.) sapling performance was quanti®ed in three native forests located in two Mediterranean mountains, the Sierra Nevada and Sierra de Baza (SE Spain). More than 98% of the damage to terminal shoots was caused by goats and Spanish ibex in Sierra Nevada and sheep in Sierra de Baza. Some 72% of(More)
There is an intense debate about the effects of postfire salvage logging versus nonintervention policies on regeneration of forest communities, but scant information from experimental studies is available. We manipulated a burned forest area on a Mediterranean mountain to experimentally analyze the effect of salvage logging on bird-species abundance,(More)
Sleepiness and sleep quality in medical students of a Peruvian university Abstract Objective: To determine the degree of excessive daytime sleepiness and sleep quality in medical students. Design: Cross-sectional survey. Setting: Universidad Peruana Cayetano Heredia. Participants: Medical students. Interventions: No probabilistic sample of the sixth (76(More)