Figure captions
Figure 1:  Life cycle of  poplar rusts in New Zealand The smaller inner circle represents polycyclic infection of poplars by urediniospores, with the potential epidemic period represented by the bold line, and potential for facultative overwintering on poplar is represented by the dashed line. Continued cycling by Melampsora larici-populina  during mild winters on semi-evergreen poplars facilitates earlier build-up of epidemics. Melampsora medusea  can only infect poplar and must overwinter in the uredinial stage, possibly via mycelia surviving in leaf buds.  The larger outer circle illustrates the full macrocyclic life cycle of M. larici-populina  involving four additional spore stages in which the pathogen must infect the alternate host (conifers, primarily larch (Larix  sp.)) before the aeciospore stage can infect poplar and resume the cyclic urediniospore stage. This figure is based on figures presented in Spiers (1990) and Vialle et al. (2011). Images of hosts were sourced from the National Forestry Herbarium, Scion. 2020. NZFRI online dataset. nzfri.scionresearch.com, accessed in March 2022.
Figure 2 . Flow chart showing expected countervailing influences of mild climate with semi-evergreen habit in poplar rust pathosystem,
Figure 3. Diagram outlining interplays between factors in the ‘triangle’ involving host plant, pathogen and environment.
Table 1. Expected impacts of alternative poplar rust scenarios on poplar host [Section 2.3.1.1]