# Community Abundance of Resprouting in Woody Plants Reflects Fire Return Time, Intensity, and Type
## 4 Discussion  
We have showed that the proportion of resprouting increased as the FRI became shorter. This result was significant, as seen in the means, medians, and interquartile ranges, and was robust across all datasets that were used to derive the FRI. The same trend also emerged from the GLM when other factors influencing fire regimes were considered. This trend makes intuitive sense because investing in carbon storage to produce meristems would not be advantageous when fires are infrequent. It is consistent with evidence that species possessing resprouting capacity show high resilience to increased fire frequency [44]. Regional studies also support the idea that the ability to resprout conveys greater resilience to increasing fire frequency. [PERSON] et al. [8], for example, investigated the effects of the FRI on woody species in Western Australia shrublands and showed that non-sprouting species showed much lower resilience to shortened fire intervals than species possessing resprouting capacity. Studies on individual resprouter species, such as European beech (_Fagus sylutica_ L.), indicate that resprouting behaviour is optimal when the FRI is ca. 15 years [45], consistent with our finding that the proportion of resprouters was largest when the FRI was <20 years (Figure 2). Our approach did not allow us to discriminate what happens to the proportion of resprouters when the FRI is very short because the number of plots with an FRI <10 years was small. However, there is increasing evidence that very short FRIs are unfavourable to resprouting because they result in the depletion of carbon resources [46; 47]. There is also evidence that shifts in the timing of fires, particularly increases in fires occurring in spring, are unfavourable to the persistence of resprouters [48; 49]. We found that the proportion of resprouters is positively related to GPP. A positive relationship between resprouters and productivity was also found when using a smaller sample of plots in Australia [11]. In this study, high levels of resprouting were recorded in tropical savanna and temperate grassy woodland, while much lower levels of resprouting were found in heaths and mallee ecosystems (i.e., plant communities found in southern Australia composed primarily of shrubs with small trees of the genus _Eucalyptus_), which indicated that decreasing productivity is associated with decreasing proportions of resprouter species. This positive relationship was also found when using mean annual rainfall as a surrogate for primary production in Australia [50]. This relationship with productivity is consistent with the idea that the carbon cost associated with resprouting cannot be supported in less productive ecosystems. Furthermore, fuel loads are generally high when GPP is high, leading to high levels of fire activity and more intense fires, favouring species that invest in mechanisms to resist frequent or high-intensity fires. Previous research has shown that resprouting becomes more common with increasing disturbance severity or intensity [30; 51]. We showed that there is a significant negative relationship between the proportion of resprouters and grass cover. Most fires in areas of high grass cover are ground fires, and this result is consistent with observations that resprouters are typical of crown-fire ecosystems [5; 10; 52]. Increases in the proportion of resprouters with increasing fire frequency presumably reflect the selection of species that allocate sufficient carbon to meristem formation and regrowth. When the fire return time is low, the costs of this behaviour outweigh the benefits. This also appears to be the case when fire return times are very short and when overall productivity is low. The degree to which there is plasticity in carbon allocation to meristems is unknown, although plasticity in carbon allocation between different organs in response to drought has been demonstrated [53].