seed relies partially on wind, but mostly on gravity: the seeds will usually fall within a couple of metres of the parent tree. E. coccifera is also known to regenerate from underground lignotubers after fire. Clinal variation The distribution of E. coccifera is limited by altitude: rarely will it be found lower than , or higher than above sea level. Around the tree line is often unclear, and E. coccifera can be found in small stands or even as solitary trees. At these altitudes, E. coccifera generally grows to heights below , often blending into the alpine shrubbery at the highest reaches of its distribution. A strong correlation has been found between increasing altitude and declining stem growth rate in E. coccifera. At the lower range of its altitudinal cline, E. coccifera has been observed growing to in height, but it is more commonly measured at around , especially in sheltered sites on the Central Plateau and in Mt. Field National Park. Whilst individual and population tree height is the primary change in Eucalyptus coccifera at higher altitudes, observational studies have shown that with increasing altitude, the degree of leaf and bud glaucousness intensifies. This is most likely linked to the increased frost resistance of E. coccifera with increasing altitude. The juvenile foliage of E. coccifera is also more likely to persist for longer at high altitude. Geological associations The dominant bedrock underlying both the Mt. Field and Mt. Wellington sub-alpine habitats is Jurassic dolerite. Dolerite is also a feature of the geology of the Central Plateau. These dolerite-rich substrates provide sufficient drainage for the establishment of E. coccifera populations, which prefers well-drained soils. They also offer a potentially rich nutrient source to the sub-alpine plant communities, but the slow rate at which dolerite weathers results in soil of only moderate fertility. Associations with rainfall and water availability It is generally accepted that in Tasmania annual rainfall increases with altitude, and thus the most exposed E. coccifera populations must contend with high annual rainfall (greater than on Mt. Wellington, and around at Mt. Field). Despite this, water availability can often be an issue for E. coccifera and other subalpine species. This is due to the sporadic nature of Tasmanian rainfall, and a number of other factors including soil type, slope and wind action. The rocky substrates of sub-alpine Mt. Field and Mt. Wellington drain very effectively, therefore waterlogging isn’t generally