We examine the effects of spacing and layout on the growth and form of 3-to 4-year-old Eucalyptus globulus in a farm forestry context. Four planting layouts were chosen. These represented the range commonly in use in farm forestry: block plantings (2×4 m), triple rows (2×4 m) at 10-m intervals, single rows (2×10 m) and isolated trees (10×10 m). The physiological significance of key results is interpreted in terms of changes in the parameters of a simple plantation growth model. Under conditions where levels of direct light are high, for example during summer, block-planted trees intercepted only 38% of the light intercepted by isolated trees. On a stand basis, however, the combination of incident radiation and ground coverage declined with lower stand densities. While stand leaf area index declined from around 6 to 1 with increased spacing, individual tree leaf areas rose from around 50 m 2 in block plantings to 150 m 2 in isolated trees. The proportion of above-ground biomass found in stems declined with increasing spacing as the mass in foliage and branches increased. Stems accounted for 65% of above-ground biomass in block-planted trees but only 35% in isolated trees. The contributions of leaves and branches correspondingly rose from 19% to 35% and from 16% to 29%, respectively. Changes in biomass distribution were accompanied by increasing branch number, branch thickness, flatter branch angles and the longer retention of lower branches with greater spacing. These changes have implications for the merchantability of the timber. The efficiency of aboveground radiation conversion was constant at 0.67 g MJ -1 irrespective of spacing. We estimated that foliar maintenance respiration (R m ) accounted for about 90% of above-ground R m . On a stand basis R m costs block plantings 23.90 t DM ha -1 year -1 (50% annual above-ground photosynthetic production) compared with 6.22 t DM ha -1 year -1 (40% annual above-ground photosynthetic production) in stands of isolated trees.

These cyanobacterial lichens are a tripartite lichen symbiont combination in which the mycobiont has two primarily photosynthetic photobionts, 'co-primary photobionts', a cyanobacterium (dominant) and a green alga. This demonstrates high flexibility in photobiont choice by the mycobiont in the Peltigerales. Overall thallus appearance does not change whether one or two photobionts are present in the cyanobacterial thallus. This suggests that, if there is a photobiont effect on thallus structure, it is not specific to one or the other photobiont.

Carpetgrass (Axonopus affinis Chase) was described in terms of its botany, origin, distribution, seasonal growth, habitat, and dispersal. Factors that determine its agronomic importance were examined. Emphasis was given to management and ecological factors which influence competition between carpetgrass and sown pasture species. It is concluded that the management strategies that have been developed and successfully adopted in Queensland and New South Wales need to be tested for use in irrigated pastures in northern Victoria