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2009-01-01
Reid, T.A., Cahill, J.F., Navabi, A.
Competition with weeds decreases crop yields globally. Breeding for competitive ability against elevated weed pressure can be difficult because the selection for specific traits which contribute to competitive ability may result in yield losses. The widely studied International Triticeae Mapping...
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Climate and nutrient influences on the growth of white spruce trees in the boreal forests of the Yukon
Download2008
Krebs, C.J., Boonstra, R., Desantis, L., Hik, D.S.
The boreal forests of North America are undergoing major changes because of the direct effects of global warming and increased CO2 levels. Plant production in the boreal forest is nutrient limited, and we examined how long-term fertilization affected growth of white spruce Picea glauca in the...
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2005
Hik, D.S., Zazula, G., Gillis, E.A., Morrison, S.F.
Male arctic ground squirrels (Spermophilus parryii) rely on food they cached the previous year for the energy they need to compete for mates each spring. We collected cheek-pouch contents of arctic ground squirrels trapped during three summers (2000–02) as an indication of what squirrels cached....
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2007
Small-scale vertical aerial photographs taken in 1947 and 1948 covering 200 km2 of the Kluane Ranges, southwest Yukon, were compared with corresponding photographs taken in 1989 for the purpose of characterizing changes in the distribution and abundance of white spruce (Picea glauca (Moench)...
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Light, wind, and touch influence leaf chemistry and rates of herbivory in Apocynum cannabinum (Apocynaceae)
Download2006-01-01
Cahill, J.F., Ingersoll, C.M., Niesenbaum, R.A.
Simply visiting and manipulating plants in a way consistent with measurement in typical ecological studies influences the amount of leaf herbivory experienced by some plant species. We examined the mechanistic basis for why Apocynum cannabinum is particularly responsive to such visitation and...
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Limited effects of soil nutrient heterogeneity on populations of Abutilon theophrasti (Malvaceae)
Download1996-01-01
An experiment was conducted to determine if spatial nutrient heterogeneity affects mean plant size or size hierarchies in experimental populations of the weedy annual Abutilon theophrasti Medic. (Malvaceae). Heterogeneity was imposed by alternating 8 X 8 X 10 cm blocks of low and high nutrient...
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2004
Paquet, P.C., Hik, D.S., Frame, P.F., Cluff, H.D.
Wolves (Canis lupus) on the Canadian barrens are intimately linked to migrating herds of barren-ground caribou (Rangifer tarandus). We deployed a Global Positioning System (GPS) radio collar on an adult female wolf to record her movements in response to changing caribou densities near her den...
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Plant phenotypic plasticity belowground: a phylogenetic perspective on root foraging trade-offs
Download2005-01-01
Many plants proliferate roots in nutrient patches, presumably increasing nutrient uptake and plant fitness. Nutrient heterogeneity has been hypothesized to maintain community diversity because of a trade-off between the spatial extent over which plants forage (foraging scale) and their ability to...
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Population-level Responses to Nutrient Heterogeneity and Density by Abutilon Theophrasti (Malvaceae): An Experimental Neigborhood Approach
Download1998-01-01
An experimental approach was used to examine the effects of spatial nutrient heterogeneity and planting density on the sizes of plants within populations of Abutilon theophrasti. Planting locations were generated using random numbers and replicated among populations growing on two different...