Radial growth response of four dominant boreal tree species to climate along a latitudinal gradient in the eastern Canadian boreal forest

Abstract

To address the central question of how climate change influences tree growth within the context of global warming, we used dendroclimatological analysis to understand the reactions of four major boreal tree species -Populus tremuloides, Betula papyrifera, Picea mariana, and Pinus banksiana -to climatic variations along a broad latitudinal gradient from 46 to 541N in the eastern Canadian boreal forest. Tree-ring chronologies from 34 forested stands distributed at a 11 interval were built, transformed into principal components (PCs), and analyzed through bootstrapped correlation analysis over the period 1950-2003 to identify climate factors limiting the radial growth and the detailed radial growthclimate association along the gradient. All species taken together, previous summer temperature (negative influences), and current January and March-April temperatures (positive influences) showed the most consistent relationships with radial growth across the gradient. Combined with the identified species/site-specific climate factors, our study suggested that moisture conditions during the year before radial growth played a dominant role in positively regulating P. tremuloides growth, whereas January temperature and growing season moisture conditions positively impacted growth of B. papyrifera. Both P. mariana and P. banksiana were positively affected by the current-year winter and spring or whole growing season temperatures over the entire range of our corridor. Owing to the impacts of different climate factors on growth, these boreal species showed inconsistent responsiveness to recent warming at the transition zone, where B. papyrifera, P. mariana, and P. banksiana would be the most responsive species, whereas P. tremuloides might be the least. Under continued warming, B. papyrifera stands located north of 491N, P. tremuloides at northern latitudes, and P. mariana and P. banksiana stands located north of 471N might benefit from warming winter and spring temperatures to enhance their radial growth in the coming decades, whereas other southern stands might be decreasing in radial growth.

Radial-Growth Response of Forest-Tundra Trees to Climate in the Western Hudson Bay Lowlands

“…Girardin et al, 2005;Tardif et al, 2008). Some researchers have suggested that the negative association with previous summer temperatures was related to moisture stress and found a positive correlation with previous June precipitation to support this hypothesis (Hofgaard et al, 1999;Huang et al, 2009). However, no clear relationship between radial growth and the previous year's precipitation was found in this study.…”

Floristic composition, biological spectrum and phenological pattern of vegetation in the subtropical forest of Kotli District, AJK, Pakistan

“…Similarly urbanization is a major factor of global climatic change. There was an uneven fluctuation in temperature throughout the year in urban areas of Canada which has direct impact on vegetation phenology [67]. Similarly in our case, rise in temperature from March to May favored the flowering of plants and further increase in temperature caused onset and maturation of fruits from June -September.…”

Vulnerability assessment to climate change of three ecosystem-based forest management projects in Quebec

“…BSP) and jack pine (Pinus banksiana Lamb.) above 47°N may benefit from an increase in winter and spring temperatures and respond with increased growth rates (Huang et al 2010). The relationship between temperature and tree growth suggests that an increase in temperatures would favour growth by, amongst other factors, lengthening the growth season (20 to 27 days by 2050 according to the model used; Logan et al 2011).…”

“…Climate changes that will particularly affect boreal forests include increased atmospheric temperatures, an altered precipitation regime (frequency and amplitude of events), an alteration in seasonality (shorter, milder winters and earlier and longer summers, Ouranos 2010), and changes in the frequency and amplitude of extreme meteorological events (e.g., droughts, freeze/thaws, heavy rain; Logan et al 2011). These changes will have a number of important consequences, including: i) an alteration in the frequency and severity of natural disturbances; ii) an increase in the area occupied by early successional species in response to increased disturbances (fire, flooding, insect epidemics); iii) changes in the spatial and temporal occurrences of species (forest composition); iv) modifications in radial tree growth and, thus, on forest productivity; v) latitudinal and altitudinal migrations of species distributions (at locations where edaphic conditions and ecological processes, such as natural disturbances and competition, are favourable); vi) an increased presence in invasive and exotic species; and vii) an alteration in the quantity and quality of faunal habitat and predator-prey relationships (Prato 2008, Huang et al 2010, Ouranos 2010, Logan et al 2011). These biophysical modifications will surely have consequences on the ecological services offered by forests including the abundance of woody and non-woody forest products, the production of oxygen, regulation of climate, sequestration of carbon, as well as impacting recreational and cultural values and activities (Hassan et al 2005).…”