Vertical leaf nitrogen (N) gradient within a canopy is classically considered as a key adaptation to the local light environment that would tend to maximize canopy photosynthesis. We studied the vertical leaf N gradient with respect to the light gradient for wheat (Triticum aestivum) canopies with the aims of quantifying its modulation by crop N status and genetic variability and analyzing its ...

The acetate-to-ergosterol technique was used to estimate fungal productivity of three species of aquatic hyphomycetes growing in decomposing ash leaves in stream microcosms. Following a lag of 20-88 min, incorporation of acetate into ergosterol was linear for at least 10 h. Substrate saturation was reached in the mM range, and there was no indication of isotope dilution. For one species, Articu...

Mulberry (Morus species) leaf is the sole food for monophagous silkworms, Bombyx mori L. Abiotic stresses such as drought, salinity, and high temperature, significantly decrease mulberry productivity and post-harvest water loss from leaves influence silkworm growth and cocoon yield. Leaf surface properties regulate direct water loss through the cuticular layer. Leaf surface waxes, contribute fo...

The lobed leaf character is a unique morphologic trait in crops, featuring many potential advantages for agricultural productivity. Although the majority of watermelon varieties feature lobed leaves, the genetic factors responsible for lobed leaf formation remain elusive. The F2:3 leaf shape segregating population offers the opportunity to study the underlying mechanism of lobed leaf formation ...

Recent work has identified a worldwide "economic" spectrum of correlated leaf traits that affects global patterns of nutrient cycling and primary productivity and that is used to calibrate vegetation-climate models. The correlation patterns are displayed by species from the arctic to the tropics and are largely independent of growth form or phylogeny. This generality suggests that unidentified ...

Human alteration of atmospheric composition affects foliar chemistry and has possible implications for the structure and functioning of detrital communities. In this study, we explored the impacts of elevated carbon dioxide and ozone on aspen (Populus tremuloides) leaf litter chemistry, earthworm (Lumbricus terrestris) individual consumption and growth, and springtail (Sinella curviseta) popula...

Precipitation amounts and patterns at high latitude sites have been predicted to change as a result of global climatic changes. We addressed vegetation responses to three years of experimentally increased summer precipitation in two previously unaddressed tundra types: Betula nana-dominated shrub tundra (northeast Siberia) and a dry Sphagnum fuscum-dominated bog (northern Sweden). Positive resp...

Monthly mean global green leaf area and photosynthetically active radiation estimated from observations made from several geostationary and polar orbiting satellites were used to estimate potential, (i.e., unstressed) gross primary productivity of terrestrial vegetation from 1982 to 1990. Mean annual gross primary productivity was estimated to be about 179.9 q1.6 Pg C (1 Pg = 1015 g)o Grasses a...