The Orongorongo Valley is located 18 km east of Wellington (4121’S, 17458’E). The study area of 4.4 ha is located at about 100 m a.s.l., and comprises forest with scattered emergent Metrosideros robusta and Dacrydium cupressinum over a canopy of Elaeocarpus dentatus, Laurelia novae-zelandiae, Melicytus ramiflorus, Hedycarya arborea, Knightia excelsa, Weinmannia racemosa, Schefflera digitata and...

During the last century, the density of Ashe juniper (Juniperus ashei Buchholz) has greatly increased in oak savannahs of central Texas. Recently, juniper removal has been advocated as a regional water conservation tool. In this study, we investigated whether juvenile trees released from an overstory canopy after clearing exhibited accelerated growth and water consumption. We compared leaf-leve...

The Persian oak, Quercus brantii, trees in the Zagros region of Western Iran have been in decline since 2000. The decline is assumed to be highly connected with changes in meteorological parameters. Our objectives were to quantify the long-term trends in meteorological parameters and reference evapotranspiration (ET0) in the Zagros region and estimate ecohydrological parameters highly affected ...

With fire suppression, many western forests are expected to have fewer gaps and higher stem density of shade-tolerant species as light competition becomes a more significant influence on stand pattern and composition. We compared species composition, structure, spatial pattern, and environmental factors such as light and soil moisture between two old-growth forests: Pacific Northwest western he...

D oes genotypic variation in leaf form and function among tree species reflect adult height or only the seedling regeneration niche? For trees in closed canopy forests, typical adult tree height directly indicates the position of the species in the light hierarchy of the canopy. However, it is unknown whether trees that characteristically differ in mature height have similar or different canopy...

Canopy gaps induced by tree falls have an important ecological role in forest communities since they act on forest sylvigenesis, dynamics and specific composition, mainly through modifications of the light context they involve. Some factors responsible for tree fall occurrences become more influent on sloping areas, particularly crown asymmetry. We have already shown in previous work (Robert, 2...

variable rate spray applications using proportional control systems can greatly reduce pesticide use and off-target contamination of environment in orchards. variable rate spraying of the canopy allows growers to apply pesticides only to the target, only use the correct quantity according to canopy size, season and growth stage and to apply plant protection products in an economic and environme...

Questions: How do fire frequency, tree canopy cover, and their interactions influence cover of grasses, forbs and understorey woody plants in oak savannas and woodlands? Location: Minnesota, USA. Methods: We measured plant functional group cover and tree canopy cover on permanent plots within a long-term prescribed fire frequency experiment and used hierarchical linear modeling to assess plant ...

BACKGROUND The diversity and composition of the microbial community of tree leaves (the phyllosphere) varies among trees and host species and along spatial, temporal, and environmental gradients. Phyllosphere community variation within the canopy of an individual tree exists but the importance of this variation relative to among-tree and among-species variation is poorly understood. Sampling te...

Trees exposed to elevated CO2 partial pressure ([CO2]) generally show increased rates of photosynthesis and growth, but effects on leaf respiration are more variable. The causes of this variable response are unresolved. We grew 12-year-old sweetgum trees (Liquidambar styraciflua L.) in a Free-Air CO2 Enrichment (FACE) facility in ambient [CO2] (37/44 Pa daytime/nighttime) and elevated [CO2] (57...