Effects of water deficits on leaf turgor maintenance processes were analyzed for pear trees (Pyrus communis L. cv. "Barlett") grown in 120-liter containers. Four irrigation treatments were applied: a well-watered control treatment, a spring water stress cycle (Sp), a summer water stress cycle (Su), and a spring plus summer water stress cycle (Sp + Su). For the Sp treatment, water application wa...

The purpose of this research is to analyze heat waves characteristics in the warm period of the year as a climatic hazard in Iran. In this study, the daily maximum temperature is taken at 44 synoptic stations during the period 1981-2010. These temperature values were used to extract the intensity, frequency and duration of heat waves using percentile thresholds of 90, 95, and 98. The results sh...

The increasing frequency of severe drought and heat events under climate change is a major cause for concern forest productivity survival. One potential solution to improve resilience may involve tree removal reduce competition. To quantify benefits partial cutting systems drought, we use tree-ring data from long-term experiment in dry ecosystem western Canada, composed primarily mature interio...

terminal heat and drought are the main constraints for wheat production in the vast and diverse semi-tropical rainfed regions of iran. high temperature stress during wheat’s reproductive stage is particularly detrimental, reducing both individual kernel weight and kernel number. identification of adapted genotypes can improve grain yield and its stability under heat stress conditions. selection...

Wildfires constitute a major hazard in the Iberian Peninsula, being responsible for very significant amounts of burned area every year. In this work we analyzed records of fire occurrences in Portugal and Spain for the 1980-2005 period (a total of 66 sub-regions), in order to organize a comprehensive Iberia database. A k-means cluster analysis was then performed in order to distinguish fairly i...

Species differ regarding their drought tolerance and individuals of a given species can modify their morphology and physiology in response to drought. However, since evolutionary and ecological selective pressures differ, individual and interspecific responses to drought might not match. We determined summer survival and a number of ecophysiological variables in two factorial experiments with s...

Assessing intra-specific variation in drought stress response is required to mitigate the consequences of climate change on forest ecosystems. Previous studies suggest that European larch (Larix decidua Mill.), an important European conifer in mountainous and alpine forests, is highly vulnerable to drought. In light of this, we estimated the genetic variation in drought sensitivity and its degr...

Synthesis of heat shock proteins (HSPs) in the leaves of a drought- and heat-resistant (line ZPBL 1304), and a drought- and heat-sensitive (line ZPL 389) line of maize (Zea mays L.) was studied under two environmental stress treatments: (a) soil drying and high temperature and (b) high temperature. In the first treatment 13-day-old plants were exposed to 7-day soil drying followed by high tempe...