1. Secondary colonization of leaf shelters constructed by caterpillars has been reported from a number of systems. Both the mechanism (larval or adult movement vs. oviposition) and the cues used by arthropods in locating leaf shelters, however, have received little attention. 2. Artificial leaf shelters (i.e. leaf ties or pairs of leaves clipped together to form sandwiches) were constructed on ...

The Oak genus (Quercus L.) is one of the most important genera of beach family (Fagaceae) that has ecological and economical importance. Chestnutleaf oak (Quercus castaneifolia C.A. Mey.) is native to Iran and distributed in Hyrcanian forests. Pure and mixed stands of this taxon have covered about 6.5 % of Hyrcanian forests. This study was undertaken to evaluate the effects of ecological factor...

Z. Naturforsch. 54c, 8 1 2 -8 2 3 (1999); received December 1, 1998/March 2, 1999 Biomass, Carbohydrate. Drought Stress, Elevated C 0 2, Leaf Anatomy Young sessile oak (Quercus petraea) trees were exposed for one vegetation period in closed environmental chambers in a crossed factorial study on effects to varied C 0 2 concentrations, ozone concentrations and irrigation treatments. Elevated C 0 ...

Here, we investigated the physiological and structural leaf responses of seedlings of two evergreen and two deciduous Quercus species, grown in a glasshouse and subjected to contrasted conditions of light (low, medium and high irradiance) and water (continuous watering vs 2-months drought). The impact of drought on photosynthetic rate was strongest in high irradiance, while the impact of shade ...

Several hurricanes struck Florida, U.S. in 2004 and 2005 causing widespread damage to urban and rural areas. We measured the impacts of five of these hurricanes on the urban forest and combined these results with four other hurricanes to present an assessment of wind resistance for southeastern United States coastal plain tree species. Urban forest loss was positively correlated with wind speed...

Bacterial leaf scorch is caused by Xylella fastidiosa Wells et al. The pathogen causes chronic leaf scorch and decline in elm, oak, sycamore, and maple. X. fastidiosa has a wide host range and is responsible for many other serious diseases including Pierce's disease of grape, phony disease of peach, and citrus variegated chlorosis. Its role in shade tree disorders has only recently been recogni...

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests (Quercus petraea L.) that were heavily infested by the leaf herbivores winter moth (Operophtera brumata L.) and mottled...

Plant phenology is a sensitive indicator of the effects of global change on terrestrial ecosystems and controls the timing of key ecosystem functions including photosynthesis and transpiration. Aerial drone imagery and photogrammetric techniques promise to advance the study of phenology by enabling the creation of distortion-free orthomosaics of plant canopies at the landscape scale, but with b...

Assessing photosynthesis rates with remote sensing is important for tracking the physiological state of plants. The photochemical reflectance index (PRI) is a good estimator of short-term light-use efficiency (LUE) at the leaf scale but its responses to environmental factors are poorly understood. In this study, we assessed changes in the responses of the PRI to ozone exposure and to an increas...

feeding performance of the green oak leaf roller, tortrix viridana (linnaeus) was determined on three host plants including quercus libani oliv, quercus infectoria oliv, and quercus branti lindl, under laboratory conditions. mean total leaf weight consumed by larvae was the highest on q. branti (0.31 g) and the lowest on q. libani (0.14 g).the feeding index was the highest on q. libani while th...