An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
... Temperature data from ten weather stations across Canada were used to model the effects of climate warming on the timing of bud burst and the risk of frost damage to white spruce (Picea glauca (Moench) Voss). There was evidence of increasingly earlier dates of bud break over the course of this century at half of the stations examined (Amos and Brome, Quebec; Cochrane, Ontario; Fort Vermilion, Albe ...
height; plant characteristics; Picea glauca; boreal forests; mixed forests; seedlings; site preparation; microclimate; canopy; stand density; relative humidity; soil temperature; air temperature; night temperature; frost; mortality; buds; dormancy breaking; photosynthesis; stomatal conductance; diameter; shelterwood systems
Abstract:
... Microclimate and seedling response of planted white spruce were investigated under four canopy densities control--a 120-year old uncut aspen/white spruce stand, low and high residual densities of shelterwood canopy, and clearcut) and three site preparation treatments in the Lower Foothills of central Alberta. The partial canopy of the shelterwoods had a less extreme environment than the clearcut: ...
... The kinetics of primary dormancy loss were investigated in seeds of horse chestnut (Aesculus hippocastanum L.) harvested in four different years. Freshly collected seeds from 1991 held for up to 1 year at temperatures-between 2 degrees C and 42 degrees C exhibited two peaks in germination (radicle growth), representing a low temperature (2-8 degrees C) and a high temperature response (31-36 degree ...
... AsbtractsEnvironmental conditions affect seed softening patterns of annual legumes. These patterns have not been well established for cool, temperate environments. This work examines the effect of genotype and of growing and softening environments on the short-term loss of dormancy in subterranean clover (Trifolium subterraneum L.) during the summer and early autumn. Burrs of six cultivars and one ...
... Vegetative-bud dormancy in peach (Prunus persica L. Batsch) trees is known to be correlated, at least partially, with properties of the underlying bud tissues during winter. Variations in the activity and amount of plasma-membrane H+ -ATPase were observed. A full-length cDNA, PPA2 (Prunus persica H+ -ATPase 2) and three partial cDNAs (PPA1, PPA3 and PPA4) for the plasma-membrane H+ -ATPase from pe ...
... The fungal pathogen, Entomophaga maimaiga causes epizootics in populations of the important North American forest defoliator gypsy moth (Lymantria dispar). Increasing use of this fungus for biological control is dependent on our ability to produce and manipulate the long-lived overwintering resting spores (azygospores). E. maimaiga resting spores undergo obligate dormancy before germination so we ...
Populus tremuloides; dormancy; acclimation; air temperature; carbohydrate metabolism; cold tolerance; altitude; buds; dormancy breaking; cryopreservation; raffinose
Abstract:
... Changes in metabolism that accompany cold acclimation and deacclimation, such as increasing levels of raffinose family oligosacharides (RFO) during cold acclimation demonstrated in several woody species, are of interest in a search for genetic control of environmental adaptation by cold-hardy woody plants. This study examined the relationship of temperature to endodormancy and cold hardiness in tr ...
imbibition; seed germination; seed dormancy; testa; interspecific variation; soil temperature; smoke; air temperature; heat; duration; dormancy breaking; detection; permeability; Western Australia
Abstract:
... Exposure to high temperatures (40-60 degrees C) over several days to months (simulating summer soil conditions) or to extremely high temperatures (80-120 degrees C) for periods ranging from minutes to several days (simulating the heat of an extreme fire) promoted germination in five (including one legume species) of the seven species tested from southwestern Australia. Heat, a collective term for ...
... This paper presents two models of budbreak on canes of 'Hayward' kiwifruit (Actinidia deliciosa). A conventional 'chill unit' (CU) type model is compared with an alternative 'loss of potential' (LOP) approach, which assumes that the number of buds developing in spring depends on climate and node position-dependent bud-to-bud interactions that vary in duration and intensity. Both models describe ho ...
... The boll weevil, Anthonomus grandis Boheman, enters a diapause state to survive winters in temperate regions and subsequently emerges from overwintering habitats to infest squaring cotton in the spring. Previous research has found that boll weevil overwintering emergence is closely associated with climatic patterns of temperature and precipitation. The objectives of this study were to determine th ...
Picea abies; forest trees; budbreak; dormancy breaking; dormancy; tree growth; light; duration; photoperiod; tree age; air temperature; climatic factors; temporal variation; analysis of variance; Sweden