Solving the conundrum of plant species coexistence: water in space and time matters most.

around the world for these traits. Peach is particularly amenable for forward genetic studies because it has a small genome (approximately half the size of the P. trichocarpa genome) with little duplication history, is self-fertile, has a generation time as short as 2–4 yr and significant genomic resources are available (Shulaev et al., 2008). Recent work has demonstrated the utility of peach to map and sequence candidate genes for important winter-dormancy traits (Bielenberg et al., 2008; Fan et al., 2010). Apple, in turn, possesses a very robust transformation capability for reverse genetics (Shulaev et al., 2008). Research on several species will be needed to truly understand ecosystem-level phenological responses to climate change because induction of growth cessation, bud set and bud flush is regulated differently in different species. For example, in Malus and Pyrus spp. growth cessation and bud set appear to be regulated by low temperatures alone without the involvement of photoperiod (Heide & Prestrud, 2005). While trees dominate the discussion of perenniality, many herbaceous species also develop buds and enter winter dormancy, often from underground structures (Horvath et al., 2002). It is clear that parallel work on multiple plant systems will be important to incorporate the biological diversity of perennial species. The community of perennial biology researchers will need to continue to be adept at applying data and concepts gained from one system to another.