Now showing items 21-30 of 386
Song copying and cultural transmission in indigo buntings
(Elsevier, 1993-12)
Abstract. First-year male indigo buntings, Passerina cyanea, copy the song of a neighbouring male during their first breeding season. To determine whether they assess their neighbours and copy selectively the songs of ...
Mio-pliocene seasonality on the snake river plain: comparison of faunal and oxygen isotopic evidence
(Elsevier, 1994-02-28)
Analysis of fish faunas and oxygen isotopic composition of a fish otolith from lacustrine deposits of southwestern Idaho provide a means of evaluating regional Miocene and Pliocene climates. A disharmonious assemblage ...
Interactive effects of light, leaf temperature, CO 2 and O 2 on photosynthesis in soybean
(Springer-Verlag, 1985-08)
A biochemical model of C 3 photosynthesis has been developed by G.D. Farquhar et al. (1980, Planta 149, 78–90) based on Michaelis-Menten kinetics of ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase, with a potential ...
Patterns in tropical leaf litter and implications for angiosperm paleobotany
(Elsevier, 1994-03)
One hectare of undisturbed Amazonian forest, containing about 175 species of trees larger than 10 cm diameter at breast height, was studied to determine the relationship between high-richness forest and the autochthonous ...
Clonal variation in above- and below-ground growth responses of Populus tremuloides Michaux: Influence of soil warming and nutrient availability
(Kluwer Academic Publishers; Springer Science+Business Media, 1999-03)
Trembling aspen (Populus tremuloides Michx.) is the most widely distributed tree species in North America making it important to terrestrial carbon and nutrient cycles. Due to anthropogenic climate change high latitude ...
Rates of evolution on the time scale of the evolutionary process
(Kluwer Academic Publishers; Springer Science+Business Media, 2001-11)
A generational time scale, involving change from one generation to the next, is the time scale of evolution by natural selection. Microevolutionary and macroevolutionary patterns reflect this process on longer time scales. ...
Conservation of biodiversity in coffee agroecosystems: a tri-taxa comparison in southern Mexico
(Kluwer Academic Publishers-Plenum Publishers; Kluwer Academic Publishers ; Springer Science+Business Media, 2003-06)
We compare species richness of birds, fruit-feeding butterflies and ground-foraging ants along a coffee intensification gradient represented by a reduction in the number of species of shade trees and percentage of shade ...
Faecal proteinases of the fungus-growing ant, Atta texana: Properties, significance and possible origin
(Elsevier, 1975-10)
The proteolytic activity previously reported in the faecal fluid of fungus-growing ants is due to the presence of three enzymes. These enzymes have been partially purified and characterized. One is a serine proteinase; the ...
Cell elongation in the grass pulvinus in response to geotropic stimulation and auxin application
(Springer-Verlag, 1976-01)
Horizontally-placed segments of Avena sativa L. shoots show a negative geotropic response after a period of 30 min. This response is based on cell elongation on the lower side of the leaf-sheath base (pulvinus). Triticum ...
The effect of mean and variance in resource supply on survival of annuals from Mediterranean and desert environments
(Springer-Verlag, 2004-10)
Resource availability is often characterized by mean annual amounts, while ignoring the spatial variation within habitats and the temporal variation within a year. Yet, temporal and spatial variation may be especially ...