Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit zone to reduce the leaf photosynthetic area, and to increase sunlight exposure of grape bunches. Apical leaf removal is not commonly practiced, and therefore its influence on canopy structure and resultant wine aroma is not well-studied. Th...

Extensive regions of interior Douglas-fir (Pseudotsuga menziesii var. glauca, IDF) forests in North America are being damaged by drought and western spruce budworm (Choristoneura occidentalis). This damage is resulting from warmer and drier summers associated with climate change. To test whether defoliated IDF can directly transfer resources to ponderosa pine (Pinus ponderosae) regenerating nea...

Variation in the effectiveness of biocontrol agents on the weed Parthenium hysterophorus L. was evaluated at two properties (Mount Panorama and Plain Creek) in Queensland, Australia for four years (1996-2000) using a pesticide exclusion experiment. At Mount Panorama, higher levels of defoliation by the leaf-feeding beetle Zygogramma bicolorata Pallister and galling by the moth Epiblema strenuan...

In May 2007, a widespread frost event defoliated much of Utah's high elevation aspen. About 5 weeks later, the frost-defoliated aspen produced a second leaf flush. The objective of this study was to characterize changes in leaf morphology and function in re-flush leaves following frost defoliation. Leaf size and thickness, photosynthesis, carbohydrate and nutrient status, and defense chemistry ...

Outbreaks of folivorous Lepidoptera caterpillars are common in temperate forests (Ives and Wong 1988, Butterworth 1990). The high fat content, low chitin content, and large size of these larvae make them an important component of the diet of many temperate birds (Betts 1955, Robinson and Holmes 1982, Holmes and Schultz 1988, Sample et. al. 1993). Outbreaks of most species should increase availa...

• Here, we studied patterns of covariation of 10 leaf nutrients in expanding and mature leaves of the evergreen shrub Daphne laureola (Thymelaeaceae) in southern Spain. Changes in mean values and covariances of nutrients during leaf development may be relevant for plant fitness through herbivory if variation in leaf nutrients influences plant defoliation. • We analysed the between-population an...

BACKGROUND AND AIMS Dryopteris crassirhizoma is a semi-evergreen fern growing on the floor of deciduous forests. The present study aimed to clarify the photosynthetic and storage functions of overwintering leaves in this species. METHODS A 2-year experiment with defoliation and shading of overwintering leaves was conducted. Photosynthetic light response was measured in early spring (for overw...

Pine processionary moth (PPM) is one of the most destructive insect defoliators in the Mediterranean for many conifers, causing losses of growth, vitality and eventually the death of trees during outbreaks. There is a growing need for cost-effective monitoring of the temporal and spatial impacts of PPM in forest ecology to better assess outbreak spread patterns and provide guidance on the devel...

1. The orchid Tipularia discolor possesses two to five subterranean corms containing a high concentration of total non-structural carbohydrates (TNC). W e investigated the role of corms in the initiation of new growth following seasonal dormancy, in reproduction, and in the response of plants to artificial defoliation. 2. Severance of older corms (representing c. 3O0/0 of total corm biomass) in...