Impact of repeated defoliation on jarrah (Eucalyptus marginata) saplings

Effects of fertilising with nitrogen and phosphorus on growth and crown condition of Eucalyptus globulus Labill. experiencing insect defoliation

“…However longer-term monitoring is required. The 20% defoliation threshold observed in this study is similar to defoliation thresholds observed in other studies involving insect or artificial defoliation of E. globulus (Pinkard, 2003;Rapley, 2005;Smith, 2005), although the threshold also may be influenced by the pattern (Collett and Neumann, 2002;Pinkard et al, in press) and frequency (Wills et al, 2004;Pinkard et al, in press) of defoliation.…”

“…In native Eucalyptus regnans R.T. Baker forest, insect defoliation reduced wood volume by 30% after 8 years, and in 3-year-old Eucalyptus nitens (Deane and Maiden) Maiden plantations removal of more than 50% of new-season's growth reduced stem growth for 2 years (Elek, 1997). Defoliation that involves disbudding has a longer-term effect on stem growth (Candy et al, 1992), as does chronic defoliation (Wills et al, 2004).…”

Growth responses of Eucalyptus globulus Labill. to nitrogen application and severity, pattern and frequency of artificial defoliation

“…It is well established that defoliation from herbivores can reduce growth of affected plants (Kulman, 1971;Alderfer and Eagles, 1976;Bassman and Dickmann, 1982;Candy et al, 1992;Reich et al, 1993;Elek et al, 2001;Collett and Neumann, 2002;Straw et al, 2002;Cerasoli et al, 2004;Wills et al, 2004). In Eucalyptus globulus plantations, several studies have suggested that removal of more than 20% of leaf area can result in long-term changes in stem growth (Rapley, 2005;Smith, 2005), although this is likely to be influenced by pattern and frequency of defoliation (Pinkard, 2003;Wills et al, 2004).…”

“…In Eucalyptus globulus plantations, several studies have suggested that removal of more than 20% of leaf area can result in long-term changes in stem growth (Rapley, 2005;Smith, 2005), although this is likely to be influenced by pattern and frequency of defoliation (Pinkard, 2003;Wills et al, 2004). Both browsing mammals (O'Reilly-Wapstra et al, 2002) and a number of insects (Elliott and de Little, 1984;Loch and Floyd, 2001) defoliate E. globulus plantations in Australia and are potential threats to productivity.…”

Sex-specific responses of Populus deltoides to defoliation

“…Defoliation may have negative effects on tree growth by decreased leaf area and reduced carbohydrate supply [7,8]. However, the influence of defoliation on the growth of trees is not always consistent because of the differences in frequency [9], severity, pattern [10], timing [11], and growth stage [12]. Following defoliation, plants seek to maintain leaf regrowth through compensatory growth, which is defined as the restoration of morphological and physiological changes that occur in plants following defoliation [13].…”