Advantages of early germination for growth and survival of seedlings of Acer mono under different overstorey phenologies in deciduous broad‐leaved forests

Abstract

Summary0 Acer mono is one of the earliest germinating species in hardwood forests of northern Japan[ To evaluate the advantage of early germination for the seedling establishment\ di}erences in the temporal pattern of leaf development between the seedlings and overstorey trees were investigated\ together with the timing of dry mass gain and allocation\ survival and mortality agents of seedlings[ These traits were contrasted at four sites with di}erent types of foliage phenology in the overstorey trees "FU!0 and FU!1\ forest understorey in which overstorey trees unfolded and shed the leaves as ã ush and succeedingly\ respectively^SG\ small gaps^and FE\ forest edge#[ 1 Seasonal growth patterns of the seedlings were greatly a}ected by the di}erences in the coupling of leaf development between the seedlings and the overstorey trees[ For early germinating cohorts of Acer mono\ 68\ 50\ 49 and 42) of annual dry mass gain occurred within 1 months of germination\ in FU!0\ FU!1\ SG and FE\ respectively[ After this point "canopy closure# mass increment decreased abruptly in both FU sites\ but continued to increase in both SG and FE[ Seedling mass\ however\ increased after September again in FU!1 but not in FU!0\ mainly due to earlier leaf shedding of the canopy trees in FU!1[ 2 After canopy closure\ leaf mass ratio was greatest in FU!0 where light was most limited\ but lowest in FE[ In contrast\ root mass ratio was greatest in FE but lowest in FU!0 where soil moisture was most abundant[ These traits might lead to the optimization of growth by making all resources equally limiting even after canopy closure in forest understorey[ 3 Higher seedling survival resulting from early germination was observed in all four sites\ since predators and pathogens selectively attacked late germinating individuals[ The advantage of early germination was greater in both FU!0 and FU!1 than in FE\ mainly due to large di}erences in available light for early vs[ late germinating indi! viduals in both FU sites compared with the FE site[ 4 These observations suggest that phenological traits of A[ mono such as rapid ger! mination in early spring and earlier deployment of leaves compared with overstorey trees has been selected to maximize annual mass gain and survival in understorey habitats of deciduous broad!leaved forests[ Keywords] causes of mortality\ biomass allocation\ RGR\ light\ shade avoidance Journal of Ecology "0887# 75\ 108Ð117

Seed size-number trade-off in Euterpe edulis in plant communities of the Atlantic Forest

“…Community composition can be influenced by this trait as a result of dispersal limitation processes, since the capacity of propagule movement in the landscape through wind or vertebrate dispersers is affected by seed size (Fenner and Thompson, 2005), and by seedling establishment limitation processes, since seed mass may determine seedling fitness under different water, light and nutrient conditions (Leishman and Westoby, 1994;Bond et al, 1999;Seiwa, 1998).…”

The relevance of seed size in modulating leaf physiology and early plant performance in two tree species

“…Correlations among exogenous (predictor) variables were included in the model but are not shown for clarity. GSF, light availability; DOE, date of emergence; LMA, leaf mass per area; N a , leaf nitrogen per unit area; ('Fpd), leaf predawn water potential; c5 C, leaf carbon isotope composition Standard normal quantiles Seiwa 1998). This may also explain the small but significant effect of emergence date on growth seen in the GLMM model (Table 2), with late-emerging seedlings growing less than early-emerging ones.…”

“…Emergence time is an important component of fitness (Castro 2006;Seiwa 2000;Urbieta et al 2008;Verdu and Traveset 2005) that is partly related to seed size (Du and Huang 2008;Tripathi and Khan 1990) and canopy closure (Augspurger et al 2005;Jones et al 1997;Seiwa 1998). Early emergence gives plants a performance advantage during recruitment due in part to the pre-emption of aboveand below-ground resources to competitors (Geber and Griffen 2003).…”

Survival and Growth of Seedlings of Two Rhododendron Tree Species along an Altitudinal Gradient in a Temperate Broad Leaved Forest of Arunachal Pradesh, India

“…Seasonality also affects patterns of seed production, germination, survival and seedling development [37]. In broad-leaved temperate deciduous forest, the variation in understorey light conditions is produced not only by spatial variation of overstorey structure, but also by temporal Gradient in a Temperate Broad Leaved Forest of Arunachal Pradesh, India variation among species in timing of leaf emergence [38][39][40]. Enough light is usually available for the understorey plants prior to leaf emergence of canopy trees in early spring.…”

“…Enough light is usually available for the understorey plants prior to leaf emergence of canopy trees in early spring. The earlier leaf emergence in the tree seedlings, compared with canopy trees, is a crucial factor for their survival and growth [25,40,41].…”