 The actual degree of serotiny and fire mortality in B. prionotes varies with latitude , or , more likely , climate . Observations suggest that it is always killed by fire in the north of its range , which is relatively hot and dry , and where individual plants are usually smaller , but may survive fire in the cooler , moister , south . Moreover , it is essentially non @-@ serotinous in the south , since all seed is released by the end of the second year , but seed retention increases steadily to the north , and at the northern end of its range , it typically takes around four years for a plant to release half of its seed in the absence of bushfire , with some seed retained for up to 12 years . 
