Leaf shape, including leaf size, leaf dissection index (LDI), and venation distribution, strongly impacts leaf physiology and the forces of momentum exerted on leaves or the canopy under windy conditions. Yet, little has been known about how leaf shape affects the morphological response of trees to wind load. We studied eight Quercus species, with different leaf shapes, to determine the morphol...

Plants of a single genotype of wild strawberry, Fragaria virginiana Duchesne, were grown with or without fertilizer in high (406 microeinsteins per square meter per second) and low (80 microeinsteins per square meter per second) light. High-light leaves were thicker than low-light leaves and had greater development of the mesophyll. Within a light level, high-nutrient leaves were thicker, but t...

Lolium multiflorum plants were grown under a low- or high-light regime until third leaves had emerged to one-third their final length and then were transferred to a contrasting light regime. At this stage, the leaf possesses a tissue-age gradient from tip to base; thus, the reversibility of light-acclimated responses as a function of the degree of differentiation was analyzed in individual leav...

Betula platyphylla var. japonica (white birch) has heterophyllous leaves (i.e., early and late leaves) and is a typical pioneer tree species in northern Japan. Seedlings of white birch were exposed to ozone during two growing seasons, and measurements were carried out in the second year. Early leaves did not show an ozone-induced reduction in photosynthesis because of lower stomatal conductance...

The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dry-leaf flammability (time to ignition) between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignit...

This study was conducted to determine if reproductive growth in cotton (Gossypium hirsutum L.) affects concurrent leaf development. Apparent photosynthesis (AP), stomatal conductance (Cs), soluble protein (SP), ribulose bisphosphate carboxylase (RuBisCO), and chlorophyll (Chl) were monitored in four main-stem cotton leaves which emerged at approximately 2 week intervals. The leaf which emerged ...

Cotton plants (Gossypium hirsutum L. cv 'McNair 220') at the third true leaf stage were exposed to ultraviolet radiation (UVR) for seven days and compared with controls that received only natural light. Light reflectance was spectrophotometrically measured over the 0.5-2.5 #m waveband on nonexcised leaves immediately after treatment and again seven days later. Spectral measurements were also co...

Wilf et al. (1998) analyzed leaf sizes in modern vegetation and concluded that leaf sizes accurately predict mean annual precipitation (MAP). However, we question the methods employed by these authors to derive leaf size; the modern samples are not comparable to one another or to fossil leaf assemblages, and the influence of temperature on leaf size is ignored. Data for some samples were derive...

BACKGROUND AND AIMS In tropical lowland rain forest (TLRF) the leaves of most monocots differ from those of most dicots in two ways that may reduce attack by herbivores. Firstly, they are tougher. Secondly, the immature leaves are tightly folded or rolled until 50-100 % of their final length. It was hypothesized that (a) losses of leaf area to herbivorous invertebrates are generally greatest du...

There are two optima for maximizing hydraulic conductance per vasculature volume in plants. Murray's law (ML) predicts the optimal conduit taper for a fixed change in conduit number across branch ranks. The opposite, the Yarrum optimum (YO), predicts the optimal change in conduit number for a fixed taper. We derived the solution for YO and then evaluated compliance with both optima within the x...