REVIEW Climate change and plant regeneration from seed JEFFREY L. WALCK *, SITI N. HIDAYATI *, KINGSLEY W. DIXON w z, KEN THOMPSON§ and PETER POSCHLOD } *Department of Biology, Middle Tennessee State University, Murfreesboro, TN 37132, USA, wKings Park and Botanic Garden, Fraser Avenue, West Perth, WA 6005, Australia, zSchool of Plant Biology, The University of Western Australia, Crawley, WA 6009, Australia, §Department of Animal and Plant Sciences, The University, Sheffield S10 2TN, UK, }Institute of Botany, University of Regensburg, Regensburg D-93040, Germany Abstract At the core of plant regeneration, temperature and water supply are critical drivers for seed dormancy (initiation, break) and germination. Hence, global climate change is altering these environmental cues and will preclude, delay, or enhance regeneration from seeds, as already documented in some cases. Along with compromised seedling emergence and vigour, shifts in germination phenology will influence population dynamics, and thus, species composition and diversity of communities. Altered seed maturation (including consequences for dispersal) and seed mass will have ramifications on life history traits of plants. Predicted changes in temperature and precipitation, and thus in soil moisture, will affect many components of seed persistence in soil, e.g. seed longevity, dormancy release and germination, and soil pathogen activity. More/less equitable climate will alter geographic distribution for species, but restricted migratory capacity in some will greatly limit their response. Seed traits for weedy species could evolve relatively quickly to keep pace with climate change enhancing their negative environmental and economic impact. Thus, increased research in understudied ecosystems, on key issues related to seed ecology, and on evolution of seed traits in nonweedy species is needed to more fully comprehend and plan for plant responses to global warming. Keywords: germination phenology, global climate change, recruitment, seed dormancy, seed germination, seedling emergence, soil seed bank Received 12 May 2010 and accepted 23 October 2010 Introduction Climate has a large influence on plant recruitment (Adler & Hille Ris Lambers, 2008), and at the core of regeneration, temperature and water supply (especially by precipitation) are not only critical drivers for a plant’s distribution (Woodward & Williams, 1987) but also drive seed dormancy (initiation, break) and germi- nation (radicle emergence). Hence, climatic alterations along with other environmental changes (e.g. land use) that influence ecological cues will undoubtedly affect recruitment of plants and subsequently, population dynamics (Arft et al., 1999; Diemer, 2002; Fitch et al., 2007; Walck & Dixon, 2009; Baeten et al., 2010). Early developmental stages of plants are expected to be more sensitive to climate change than adult stages, and as such, represent a major bottleneck to recruitment (Lloret et al., 2004; Fay & Schultz, 2009; Dalgleish et al., 2010). Seedling emergence is usually synchronized with seasonal changes in the environment (Baskin & Baskin, 1998; Fenner & Thompson, 2005). Germination of some species happens soon after dispersal, whereas that of other species is delayed due to dormancy until a favourable season when seedlings are likely to survive, grow, and go on to reproduce. Depending on the species, forecasted changes in ecological cues may pre- clude, delay, or enhance regeneration from seeds. Impacts at the organismal level carry on to the popula- tion and community, with very complex interactions and outcomes. For example, facilitation alters the spa- tial pattern of recruitment from that determined by germination (Batllori et al., 2009) but its role in seedling establishment varies geographically for some species (Castro et al., 2004). Information on regeneration under climate change is urgently needed for modelling vege- tation dynamics (Leishman et al., 1992; Iba ´n ˜ ez et al., 2007; Morin & Thuiller, 2009; De Frenne et al., 2010). However, the overall impact of climate change on plant regeneration has largely been neglected (Hedhly et al., 2009). Here, we evaluate the effects of climate change on plant regeneration focusing on the fate of seeds after dispersal, especially those features most impacted by temperature and moisture: release from dormancy and germination. After a brief overview of seed dormancy Correspondence: Jeffrey L. Walck, tel. 1 1 615 904 8390, fax 1 1 615 898 5093, e-mail: jwalck@mtsu.edu Global Change Biology (2011) 17, 2145–2161, doi: 10.1111/j.1365-2486.2010.02368.x r 2011 Blackwell Publishing Ltd 2145