Island dwarfing is a paraphyletic adaptation across numerous mammalian genera. From mammoths to foxes, extreme body size reduction is shared by diverse organisms that migrate to an island environment. Because it largely occurs owing to... more
Island dwarfing is a paraphyletic adaptation across numerous mammalian genera. From mammoths to foxes, extreme body size reduction is shared by diverse organisms that migrate to an island environment. Because it largely occurs owing to ecological variables, not phylogenetic ones, skeletal characters in a dwarfed taxon compared with its ancestor may appear abnormal. As a result, allometric patterns between body size and morphological traits may differ for an island dwarf compared with its ancestor. The diminutive Late Pleistocene hominin, Homo floresiensis, displays a unique character suite that is outside of the normal range of variation for any extinct or extant hominin species. To better explain these as ecological traits due to island dwarfing, this research looks at how dwarfing on islands influences limb scaling and proportions in an organism in a similar ecological niche as H. floresiensis. Here, I analyze absolute limb lengths and static allometry of limb lengths regressed on predicted body mass of dwarfed island foxes and their nondwarfed relatives. Dwarfed island foxes have significantly smaller intercepts but steeper slopes of all limb elements regressed on predicted body mass than the mainland gray fox. These allometric alterations produce limbs in the island fox that are significantly shorter than predicted for a nondwarfed gray fox of similar body mass. In addition, the humerofemoral, intermembral, and brachial indices are significantly different. These results provide a novel model for understanding skeletal variation of island endemic forms. Unique body size and proportions of H. floresiensis are plausible as ecological adaptations and likely not examples of symplesiomorphies with Australopithecus sp. Caution should be exerted when comparing an island dwarf with a closely related species as deviations from allometric expectations may be common.
It would be fair to say that the Australian koala lives its life in the slow-lane. With a typical day comprising nearly 19 hours of sleeping and lazing about in the tree-tops, koalas have earned themselves the unenviable reputation of... more
It would be fair to say that the Australian koala lives its life in the slow-lane. With a typical day comprising nearly 19 hours of sleeping and lazing about in the tree-tops, koalas have earned themselves the unenviable reputation of beingmental lightweights, with their ecological role frequently compared to that of a sloth. At the same time they’re cute, they’re cuddly, they’re iconic, and we love them. But where did Australia’s endearing marsupial come from?
Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have... more
Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have become relevant for the Brazilian citrus industry. This research had the objective to evaluate the performance of irrigated and non-irrigated ‘Tahiti’ lime trees grafted on 12 rootstocks and one interstock. Plots were distributed following a randomized block design, with four replicates and one plant per plot. Rootstocks influenced plant vigor, especially ‘Flying Dragon’ trifoliate, which reduced tree height by approximately 47% compared to the ‘Rangpur’ lime. Trees that were budded on more vigorous rootstocks showed higher yield when grown without irrigation than with irrigation. The ‘1646’ citradia and ‘Morton’ citrange rootstocks performed particularly well. On the other hand, the plants on less vigorous rootstocks showed better performance in terms of yield under irrigation than the same combinations without irrigation, especially those grafted on the tetraploid ‘Carrizo’ and ‘Troyer’ citranges, ‘Swingle’ citrumelo, ‘Davis A’ trifoliate and ‘Flying Dragon’ trifoliate. Plants budded on the ‘1708’ citradia had high yields under irrigated and non-irrigated conditions. The effect of interstock on plant vigor was dependent of rootstock. Interstocked plants on ‘Davis A’ trifoliate were higher than those without interstock. On the other hand, interstocked plants on Catania 2 ‘Volkamer’ lemon were less vigorous than those without interstock.► Invigorating rootstocks grown without irrigation induce high yield. ► Yield varies between irrigated and non-irrigated groves. ► Trifoliata ‘Flying Dragon’ is a suitable rootstock for high density ‘Tahiti’ lime.
Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have... more
Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have become relevant for the Brazilian citrus industry. This research had the objective to evaluate the performance of irrigated and non-irrigated ‘Tahiti’ lime trees grafted on 12 rootstocks and one interstock. Plots were distributed following a randomized block design, with four replicates and one plant per plot. Rootstocks influenced plant vigor, especially ‘Flying Dragon’ trifoliate, which reduced tree height by approximately 47% compared to the ‘Rangpur’ lime. Trees that were budded on more vigorous rootstocks showed higher yield when grown without irrigation than with irrigation. The ‘1646’ citradia and ‘Morton’ citrange rootstocks performed particularly well. On the other hand, the plants on less vigorous rootstocks showed better performance in terms...
Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have... more
Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have become relevant for the Brazilian citrus industry. This research had the objective to evaluate the performance of irrigated and non-irrigated ‘Tahiti’ lime trees grafted on 12 rootstocks and one interstock. Plots were distributed following a randomized block design, with four replicates and one plant per plot. Rootstocks influenced plant vigor, especially ‘Flying Dragon’ trifoliate, which reduced tree height by approximately 47% compared to the ‘Rangpur’ lime. Trees that were budded on more vigorous rootstocks showed higher yield when grown without irrigation than with irrigation. The ‘1646’ citradia and ‘Morton’ citrange rootstocks performed particularly well. On the other hand, the plants on less vigorous rootstocks showed better performance in terms...
Abstract The effect of partial ringing and treatment with organic solvents on shoot length of one-year-old potted peach (Prunus persica Batsch cv. Akatsuki) trees grafted on a wild peach rootstock was investigated. A 2-cm wide partial... more
Abstract The effect of partial ringing and treatment with organic solvents on shoot length of one-year-old potted peach (Prunus persica Batsch cv. Akatsuki) trees grafted on a wild peach rootstock was investigated. A 2-cm wide partial ring of bark was removed at a height of 15 ...