How climate change might affect tree regeneration following fire at northern latitudes: a review

New Forests - Climate change is projected to increase fire severity and frequency in the boreal forest, but it could also directly affect post-fire recruitment processes by impacting seed...     

Abdominal compartment syndrome in a dog with babesiosis

Objective: To describe a case of abdominal compartment syndrome in a dog with babesiosis. Case summary: A 9‐year‐old female Bull Terrier presented with complicated babesiosis. Additional findings including respiratory distress, abdominal distension, and a decrease in urine output associated with an elevated abdominal pressure (23.5–25 cmH₂O) led to a further diagnosis of abdominal compartment syndrome. This case report describes the clinical course of both conditions through resolution. New information provided: Abdominal compartment syndrome is not well described in the veterinary literature, but clinicians should be aware of this potential complication in critically ill patients. The pathophysiology and veterinary literature of abdominal compartment syndrome are reviewed.     

Low soil temperatures increase carbon reserves in Picea mariana and Pinus contorta

? Context

Soil temperature can limit tree growth and function, but it is often unaddressed in understanding the successional status of trees.

? Aims

We tested how soil temperature affected carbon allocation strategies of two dominant co-occurring boreal conifer species, Pinus contorta and Picea mariana.

? Methods

We measured nonstructural carbon (NSC) concentrations, biomass, and photosynthesis of dormant and actively growing 2-year-old seedlings in response to three soil temperatures (5, 10, and 20 °C) under a common ambient air temperature.

? Results

For both species, variation in carbon reserves with soil temperature was more pronounced following seedling growth than during dormancy. For both species and all organ types (roots, needles, and stems), NSC concentrations were highest when seedlings were grown at 5 than 20 °C. Mass adjusted for NSC content was negatively correlated with NSC concentration for all organ types of both species. Soil temperature had a marginally significant effect on photosynthesis of pine; seedlings grown at 10 or 20 °C acquired more carbon than seedlings grown at 5 °C. Spruce seedlings photosynthesized more when grown at 20 °C than at 5 or 10 °C.

? Conclusion

Interspecific differences in allocation of carbon may underlie the responses of P. mariana and P. contorta to cold soils and consequently their successional status.     

Breeding maize lines for complete and partial resistance to maize streak virus (MSV)

Summary S₁ to S₅ inbred lines, derived from a maize population bred for its overall resistance to three tropical viruses, were screened for resistance to maize streak virus (MSV) by artificial plant infection using viruliferous leafhoppers. Symptoms were rated and intra-line frequency distributions studied for all pedigree inbred lines. Mortality due to MSV was very low among these inbreds. Symptoms appeared later, developed slower and were less severe than in the susceptible control hybrid. Results of a study of 500 S₁ and 93 S₂ lines suggested that resistance is under genetic control via a system involving loci with major genes (with dominance for resistance) controlling high to complete resistance, associated with a genetic system involving loci with minor genes controlling partial resistance. Lines expressing complete resistance to MSV were developed from 5 cycles of inbreeding and selection. The relevance of such complete and partial resistance is discussed.Abbreviations MRPS Mean Rating for Plants exhibiting Symptoms