Sugar maple seed production in northern New Hampshire

Gap-, stand-, and landscape-scale factors contribute to poor sugar maple regeneration after timber harvest

“…The potential for source limitations to impact regeneration success is suggested by increases observed in densities of seeds and seedlings with increasing density, size, and proximity of mature seed-trees in the overstory (Ribbens et al, 1994;Garrett and Graber, 1995;Clark et al, 1998). In contrast, we did not observe a significant contribution of potential seed supply to regeneration variation Table 3 Association between gap-and stand-scale variables based on Kendall's tau rank correlation (n = 347 gaps, 59 stands).…”

“…Alternative approaches to SPP that directly measure seed production were impractical given the scale of our experiment, and as we collected field measurements over one summer, they could possibly be misleading given high interannual variation in seed production (Graber and Leak, 1992;Garrett and Graber, 1995). Our SPP estimates are intended only as an index of relative differences in seed-production potential among gaps; however, it might make a fairly poor index of potential seed supply for the other species category due to differences among stands in overstory species composition and large interspecific differences in factors like dispersal patterns and substrate requirements (Burns and Honkala, 1990;Ribbens et al, 1994;Clark et al, 1998).…”

“…As an important caveat, various factors could weaken the relationship we observed between seed-source potential and densities of seedlings and saplings. For example, high interannual variation in seed production, seed viability, seed predation, and seedling survival and spatial variation in the availability of seedling establishment substrates (Graber and Leak, 1992;Houle, 1992;Garrett and Graber, 1995) could uncouple or obscure the relationship between overstory tree sizes and distances with gap-scale seedling densities. In our study area, ironwood saplings regenerate across all habitat types, regardless of light availability, cover of non-tree vegetation, and deer densities.…”

“…Densities of seedlings are initially constrained by local seed production and availability of suitable seedbeds. Generally positive relationships among tree size, seed production, and seedling densities (Tubbs, 1977;Ribbens et al, 1994;Garrett and Graber, 1995;Fei and Steiner, 2008) imply that management decisions regarding the retention of large, mature seed-trees can impact future regeneration. Once seeds germinate, availability of soil moisture, nutrients, and light affect seedling growth (Walters and Reich, 1997;Schreeg et al, 2005;Kobe, 2006), survival (Caspersen and Kobe, 2001;Schreeg et al, 2005), and species richness (Tubbs, 1977;Runkle, 1982;Burger and Kotar, 2003;Schumann et al, 2003).…”

Mast seeding in Abies balsamea, Acer saccharum and Betula alleghaniensis in an old growth, cold temperate forest of north‐eastern North America

“…1994 for Quercus spp. ; Garrett & Graber 1995 for Acer saccharum ). The proportion of the potential seed crop represented by these shed structures was higher in years of low viable seed production (Sork et al .…”