Springtime photoinhibition constrains regeneration of forest floor seedlings of Abies sachalinensis after a removal of canopy trees during winter

Abstract

A clear-cutting of canopy trees during winter often causes severe foliar damage during the following spring in forest floor seedlings of Abies sachalinensis, a typical shade-tolerant evergreen coniferous species. The maximum photochemical efficiency of photosystem II after an overnight dark adaptation showed a temporary decrease immediately before budbreak in 1-year-old shoots of A. sachalinensis seedlings grown under full sunlight in a nursery, suggesting “springtime photoinhibition” related to the phenology of evergreen coniferous species. In the field, a greater rate of canopy tree cutting during winter was associated with more severe photoinhibition in the following spring, immediately before budbreak, which subsequently resulted in a reduction in carbon gain in 1-year-old shoots, and consequently suppressed the growth of current-year shoots. Although photoinhibition under low temperature is a well-known factor to determine the survival rate of tree seedlings during winter in cool regions, the present study additionally proposes that the temporary increase in the susceptibility to photoinhibition in springtime i.e. “springtime photoinhibition” would be a constraint for the regeneration of coniferous seedlings especially when the canopy trees are removed during winter.

Exposure to strong irradiance exacerbates photoinhibition and suppresses N resorption during leaf senescence in shade-grown seedlings of fullmoon maple (Acer japonicum)

“…However, the extent of photoinhibition in LH3 seedlings was limited on 19 th Oct because of the shorter period (1 day) of exposure to open radiation. Although the degree of photoinhibition seems to be dependent on solar radiation and air temperature as well as the timing of simulated leaf shedding ( 2018a ; 2022 ; Werner et al., 2001 ; Kitao et al., 2004 ), severer photoinhibition, as was observed in LH2, might increase the risk of incomplete N resorption by oxidative damage.…”

Photosynthetic and Growth Responses in a Pioneer Tree (Japanese White Birch) and Competitive Perennial Weeds (Eupatorium sp.) Grown Under Different Regimes With Limited Water Supply to Waterlogging

“…In all species, F v /F m measured on June 24 showed lower values than those on June 25. As there were no locational effects on light resource, indicated by GSF and SNC ( Figure 8 ), the lower F v /F m on June 24 might possibly reflect an exacerbated photoinhibition due to the lower air temperature on the previous day, that is June 23 ( Krause, 1994 ; Kitao et al, 2018 ).…”

“…The daytime average (4:00–20:00) was 17.0 and 19.3°C for 23 and 24 ( Figure 2 ), based on the meteorological data at Ikutora weather station (3 km southwest to the site). 2 As F v /F m after an overnight dark adaptation is influenced by the integrated irradiance ( Werner et al, 2001 ), and air temperature ( Krause, 1994 ; Kitao et al, 2018 ) in the previous day, daytime air temperature of the day before F v /F m measurements was shown. We took photographs above the seedlings of Japanese white birch used for the chlorophyll fluorescence measurements by placing a digital camera (Coolpix 900, Nikon, Tokyo, Japan) combined with a fisheye lens (Fisheye Lens, FC-E8, Nikon) above the seedlings.…”

“…japonica) is a pioneer deciduous broadleaf tree species native to northern Japan, which naturally regenerates from anemochory seeds preferably in open habitats. Within the framework of low-cost forest management, natural regeneration of valuable tree species after a canopy tree cutting is expected as an alternative practice to seedling planting (Kitao et al, 2018(Kitao et al, , 2019. Accordingly, natural regeneration of Japanese white birch is expected as a low-cost afforestation, as the value of woody products of Japanese white birch is increasing.…”

Does ontogeny matter for the spring temperature requirement for bud burst of two coniferous species in cool temperate forests?

“…The difference in the leaf habit of canopy trees is linked to differential snow accumulation (Suzuki et al 2008); snow depth is lower and snowmelt timing is earlier under evergreen conifers than under the canopy of deciduous conifers and open canopy in Hokkaido. There, the dominant evergreen coniferous trees (e.g., Abies sachalinensis) are shade tolerant and regenerate under the closed canopy (Iijima et al 2009), while the deciduous larch species (Larix kaempferi) are light-demanding species (Ryu et al 2009) and regenerate in open habitat (Kondo and Tsuyuzaki 1999;Iijima et al 2009;Kitao et al 2018). In addition, the bud burst timing of smaller trees is later than that of canopy trees because of the later snowmelt and later start of the accumulation of degree days for smaller trees compared with large trees despite the lower requirement of degree days for smaller trees (Marumo et al 2020).…”