Estimating the onset of cambial activity in Scots pine in northern Finland by means of the heat-sum approach

Abstract

We estimated the date of onset (Date(est)) of cambial activity by the pinning method in Scots pine (Pinus sylvestris L.) trees at Vanttauskoski (Site 1) and Laanila (Site 2) near the latitudinal limit of Scots pine in northern Finland. In each year and at each site, observations were made on a different set of five trees. The estimated dates of onset of cambial activity were compared with the corresponding heat sums, calculated in degree-days according to two models. Within years, Date(est) varied among trees by up to 15 days at Site 1 and up to 13 days at Site 2. Among years, mean Date(est) varied by 15.3 days at Site 1 and 12.0 days at Site 2. The overall mean Date(est) differed between sites by 6 days (June 5 at Site 1 and June 11 at Site 2). Among all trees in all years, the mean number of degree days (d.d.) calculated from mean daily temperature above a threshold of 5 degrees C before Date(est) ranged from 68.7 to 135 d.d. at Site 1 and from 37.4 to 154.7 d.d. at Site 2. Among years, the mean heat sum before Date(est )ranged from 94 to 112.5 d.d. at Site 1 and from 61.4 to 136 d.d. at Site 2. Variation among years in heat sum before Date(est) at Site 2 was highly significant, indicating that one or more factors other than, or in addition to, heat sum determines the onset of cambial activity in Scots pine. Similar results were obtained when heat sum was computed from the area between the sine wave generated by daily maximum and minimum temperature and the threshold temperature.

How does climate influence xylem morphogenesis over the growing season? Insights from long-term intra-ring anatomy inPicea abies

“…Stronger and more defined associations emerged when the climatic data were aligned according to the DD temperature thresholds at high elevation (especially for CD in the first ring sectors; Figs 6 and 7), but not at lower elevations (see Cuny et al, 2015). These add additional evidence and further confirm that late-spring temperature controls the onset of cambial activity and the kinetics of cell formation in cold environments (Kirdyanov et al, 2003;Seo et al, 2008;Thibeault-Martel et al, 2008;Moser et al, 2010;Olano et al, 2013). However, we also observed waterrelated constraints on tracheid morphogenesis.…”

Tree growth, cambial phenology, and wood anatomy of limber pine at a Great Basin (USA) mountain observatory

“…Simulating climate-ecosystem interactions can be hampered by non-linear interactions between biotic and abiotic factors, including microclimatic effects of vegetation cover on soil properties, either physical, such as soil temperature (Harte and Shaw 1995), or chemical, such as soil nutrients (Johnson et al 2014). Temperature is indeed a primary driver of cambial activity, in particular for interrupting winter dormancy (Gruber et al 2010;Lenz et al 2013;Oribe and Kubo 1997;Seo et al 2008). Cambial reactivation can even be artificially triggered by the localized heating of stem portions in the spring (Gričar et al 2006).…”

The Association of Intra-Annual Cambial Activities of Pinus koraiensis and Chamaecyparis pisifera planted in Mt. Worak with Climatic Factors

“…이러 한 기후변화는 산림 내 수목의 계절학적 반응 (Menzel et al 2006;Cleland et al, 2007)뿐만 아니 라, 형성층 활동을 자극하여 목재세포의 양적, 질적 특성을 결정하는 중요한 요인이 된다 Seo et al, 2008).…”

“…(Pinus sylvestris, Pinus cembra) (Eilmann et al, 2011;Oberhuber and Gruber, 2010;Seo et al, 2008), 가문비류(Picea abies, Picea mariana) (Gričar et al, 2006;Huang et al, 2014;ThibeaultMartel et al, 2008), 전나무(Abies balsamea) (Huang et al, 2014;ThibeaultMartel et al, 2008), 낙엽송(Larix decidua) Chamaecyparis pisifera planted at Mt. Worak, respectively, by monitoring of their intra-annual cambial activities.…”