Winter survial during an annual cycle of temperateand boreal-zone woody perennials is a multicomponent response. Two of these components are: (1) the timing, rate, and extent of cold acclimation (CA; Box 1), and (2) plants’ ability to sufficiently maintain its freezing tolerance (FT) until the danger of killing frosts is passed which is determined by, among other factors, plants’ ability to res...

the flowering phase of apple trees is the most critical step in relation with low temperatures and frost events. therefore, forecasting the time of flowering is important. if a model can predict the exact time of flowering, it would be feasible to care for flowers agianst late spring freezing (lsf). in this study, we evaluated three temperature-base chilling models namely: chilling hours (ch), ...

Microbial production and consumption of greenhouse gases (GHG) is influenced by temperature and nutrients, especially during the first few weeks after agricultural fertilization. The effect of fertilization on GHG fluxes should occur during and shortly after application, yet data indicating how application timing affects both GHG fluxes and crop yields during a growing season are lacking. We de...

The long-term dynamics of the calanoid copepod Eudiaptomus gracilis were analyzed in Lake Constance, a deep lake that has been influenced strongly by changes in trophic status and climate variability during the last few decades. Although copepod abundances remained rather stable throughout the study period (1970-1995), the seasonal pattern changed strongly, including a seasonal shift in the tim...

This study tests whether ERS-2 and Radarsat Standard Beam SAR data could be used to detect spring green-up of broadleaf forests on ̄ oodplains in interior Alaska. SAR data were acquired for preand post-budburst dates during the spring of 1997, 1998 and 1999. The images were radiometrically calibrated todB and then geometrically co-registered to a colour infrared Landsat TM image. Ten broadleaf ...

Wintering flower buds of cold hardy Rhododendron japonicum cooled slowly to subfreezing temperatures are known to undergo extraorgan freezing, whose mechanisms remain obscure. We revisited this material to demonstrate why bud scales freeze first in spite of their lower water content, why florets remain deeply supercooled and how seasonal adaptive responses occur in regard to extraorgan freezing...

Superoxide dismutase (SOD) gene expression was investigated to elucidate its role in drought and freezing tolerance in spring and winter wheat (Triticum aestivum). cDNAs encoding chloroplastic Cu/ZnSODs and mitochondrial MnSODs were isolated from wheat. MnSOD and Cu/ZnSOD genes were mapped to the long arms of the homologous group-2 and -7 chromosomes, respectively. Northern blots indicated that...

Spring freeze events pose a threat to vineyard productivity worldwide. We compared two methods delay grapevine budbreak for avoidance and evaluated their effects on phenology, yield components, fruit composition, postharvest parameters, including wine chemistry, carbohydrate storage, bud tolerance. The were vegetable oil-based adjuvant (Amigo) applied dormant buds at 8% 10% (v/v) late pruning w...

Vernalization is an essential process by which many temperate plant species acquire competence for flowering. Brachypodium distachyon is a model plant for temperate grasses including many cool-season forage and turfgrasses and cereals. Grasses with spring growth habit do not require vernalization for flowering and are typically less winter hardy. Yet the connection between vernalization and fre...

The wood frog ( Rana sylvatica) is a freeze-tolerant species that encounters subzero temperatures during its winter breeding season, whereas the leopard frog ( R. pipiens) is freeze intolerant and breeds in spring. Osmotic and freezing tolerances of spermatozoa from these species were inferred from spermolysis rate, integrity of the plasma membrane as judged using vital dye assay, and motility ...