The effect of heatwaves on the number of visits to national parks and reserves.

BACKGROUND: Climate change is leading to an increase in the frequency and intensity of heatwaves in many regions of the world. Climate change is also related to air pollution. Both heatwaves and air pollution have adverse health effects, and can also affect social behaviors, including tourism and touristic activities. The aim of this study was to examine the association between heatwaves, air pollution and visits to national parks and reserves in Israel. METHODS: Data on 68,518 visits in 51 national parks and reserves in Israel in the years 2016-2019 was crossed with temperature and air pollution data (represented by particulate matter PM10) and analyzed using statistical tests. RESULTS: Number of visits, as a function of temperature followed a unimodal distribution, in which more visits were reported on mild temperature days (in comparison to hot or cold days). In addition, the number of visits in sites with beaches was linearly correlated with temperature. Negative associations were found between number of visits and heatwaves, and between number of visits and exceedances in PM10 levels. CONCLUSIONS: Heatwaves were shown to have a negative effect on the number of visits in national parks and reserves in Israel. The negative association between exceedances in air pollution and number of visits may be mediated by the positive correlation between air pollution exceedance events and heatwaves.

Mechanisms of long-distance seed dispersal.

Growing recognition of the importance of long-distance dispersal (LDD) of plant seeds for various ecological and evolutionary processes has led to an upsurge of research into the mechanisms underlying LDD. We summarize these findings by formulating six generalizations stating that LDD is generally more common in open terrestrial landscapes, and is typically driven by large and migratory animals, extreme meteorological phenomena, ocean currents and human transportation, each transporting a variety of seed morphologies. LDD is often associated with unusual behavior of the standard vector inferred from plant dispersal morphology, or mediated by nonstandard vectors. To advance our understanding of LDD, we advocate a vector-based research approach that identifies the significant LDD vectors and quantifies how environmental conditions modify their actions.