Heat damage in boxed white spruce (Picea glauca [Moench.] Voss) seedlings: Its pre-planting detection and effect on field performance

Abstract

Application . Results of this study show that boxed white spruce seedlings, removed from cold storage (-2 ° C) and thawed (+5 'Q, can tolerate warm (i .e . < 20 ° C) temperatures for up to 4 days without affecting field growth performance . However, exposure to temperatures above 5 °C for any duration during transport and field storage, is not recommended . Exposure to temperatures greater than 30 °C for longer than 48 h results in severe physiological deterioration of the seedlings and must be avoided . Physiological damage due to heat stress may be detected using electrolyte leakage or root growth potential tests prior to planting of seedlings . These tests could be used to decide whether to plant white spruce seedlings that may have been heat stressed after removal from cold storage.Abstract . This study investigated the effects of holding 1+0 PSB313a white spruce (Picea glauca (Moench.) Voss) seedlings in storage boxes at air temperatures of 5, 10, 20, 30 and 40 ° C for 12, 24,48, 72 and 96 h before planting . The ability to detect physiological damage to seedlings as a result of such treatment, before planting, was also examined . After one growing season, no needle damage or mortality >8% was found for temperature treatments up to 20 ° C for 4 days . At 30 ° C and above, seedling damage and mortality increased, while bud flush, shoot height, stem diameter and shoot dry weight decreased with increasing temperature and duration of treatment. Seedling mortality in the field was 100% after the 40 °C treatment exposure for 72 h or longer. Pre-planting needle electrolyte leakage was indicative of visible needle damage 14 days after planting, whereas stem electrolyte leakage and root growth potential were more closely related to end of season plantation mortality . Despite the lack of damage observed at 20 °C or below, preplanting exposure of white spruce seedlings to temperatures above 5 °C, during transportation and field storage, is not recommended .

Rapidly detecting the effects of warm storage stress on Douglas fir seedlings

“…In another parallel study conducted on seedlings lifted from the same crop on same dates as in this study, Perks et al (2004) determined that the plants were most cold hardy in January, consistent with the higher DW values and higher resistance to the stresses of warm storage. Shoot DW decreased by about 1/3 in white spruce seedlings that had been exposed to 308C for 96 h after lifting in November in BC, Canada (Binder & Fielder 1995). Shoot and root DW were moderately but significantly correlated with survival in the greenhouse in this study, similar to previous findings for other conifer (Girard et al 1997) and broadleaf species .…”

“…Supporting this view, warm storage greatly reduced CF measurements in this study. Warm storage reduced RGP and plant quality in Douglas fir (Harper & O'Reilly 2000) and other species (Puttonen 1986;Balneaves et al 1992;Binder & Fielder 1995;Maki & Colombo 2001;Cabral & O'Reilly 2005) in previous studies.…”

Litter addition decreases plant diversity by suppressing seeding in a semiarid grassland, Northern China

“…Moreover, litter removal can indirectly inhibit seedling recruitment by reducing soil moisture (Figure b). Moreover, the increase in soil temperature inhibits seedling recruitment by sharply decreasing seed vigor (Auld & Ooi, ; Avhad & Marchetti, ; Lombraña, Porceddu, Dettori, & Bacchetta, ), or accelerating seedlings death at early stage (Binder & Fielder, ; Harper & O'Reilly, ). Litter removal does not regulate seedling recruitment by affecting ST because ST did not increase in litter removal treatment.…”

Gas exchange and chlorophyll fluorescence responses of Pinus radiata D. Don seedlings during and after several storage regimes and their effects on post-planting survival

“…RGP has often been used as a performance attribute to evaluate the quality of conifer seedlings after storage (Ritchie and Tanaka 1990;McKay 1992;Mattsson 1997) and field performance potential (Binder and Fielder 1995). In seedlings of some coniferous species new root growth is dependent primarily upon current photosynthesis, so that it is necessary that photosynthetic capacity of seedlings survives in good condition (Simpson and Ritchie 1997).…”