Influence of soil temperature and water content on fine-root seasonal growth of European beech natural forest in Southern Alps, Italy

Abstract

In tree species, fine-root growth is influenced by the interaction between environmental factors such as soil temperature (ST) and soil moisture. Evidences suggest that if soil moisture and nutrient availability are adequate, rates of root growth increase with increasing soil temperature up to an optimum and then decline at supraoptimal temperatures. These optimal conditions vary between different taxa, the native environment and the fine-root diameter sub-classes considered. We investigated the effects of seasonal changes of both ST and soil water content (SWC) on very fine (d < 0.5 mm) and fine-root (0.5 < d < 2 mm) mass (vFRM, FRM) and length (vFRL, FRL) in Italian Southern Alps beech forests (Fagus sylvatica L.). Root samples were collected by soil core method. Turnover rate was higher for the very fine (0.51) than for the fine (0.36) roots. vFRM, FRM, vFRL and FRL displayed a complex seasonal pattern peaking in summer when SWC was around 40 % and ST was around 14 °C. Above this temperature, under almost constant SWC, all above mentioned root traits decreased. vFRM, FRM, vFRL and FRL showed significant second-order polynomial relationship (p < 0.05) with SWC for both diameter classes, with the only exception of SRL. ST showed the same kind of relationship significant only with vFRM and vFRL, the latter within the 12-16 °C smaller range. Interpolation analysis between root mass and length for both diameter classes and investigated soil environmental characteristics (ST and SWC) showed a clear roundish delineation only for vFRM. In conclusion, these findings clarified the occurrence of a bimodal fine-root growth seasonal pattern for our beech forest. The optimal growth ST and SWC ranges were delineated only for very fine roots, giving further evidence on this root category as the more responsiveness to soil environmental changes. Furthermore, F. sylvatica seems to adopt an intensive strategy to cope with decreasing SWC. Finally, fine-root growth, mainly radial type, seems to be driven by SWC, whereas very fine-root growth, mainly longitudinal type, seems to be driven by ST

Comparison of ingrowth cores and ingrowth meshes in root studies: 3 years of data on Pinus pinaster and its understory

“…Variation in root biomass and root production has been associated to soil conditions such as acidity (Godbold et al 2003), moisture (Konôpka and Lukac 2013;Montagnoli et al 2014a); temperature (Finér et al 2011b;Leppälammi-Kujansuu et al 2013;Montagnoli et al 2014a) and nutrient availability (Vogt et al 1996;Jiménez et al 2009;Kochsiek et al 2013). At large scales, variations are reported along climatic gradients, between different seasons, along sequences of soil fertility and between different soil layers (Finér et al 2011a, b;Vogt et al 1996;Yuan and Chen 2010;Baddeley and Watson 2004, Kern et al 2004McCormack et al 2014).…”

Estimating forest aboveground biomass by low density lidar data in mixed broad-leaved forests in the Italian Pre-Alps

“…Quantification at various scales, from root system (Montagnoli et al 2012a(Montagnoli et al , 2014 to above-ground organs, is critical for understanding the stocks and fluxes associated with forest clearance, degradation, and regeneration, particularly given current concerns regarding global climate change (Barrett et al 2001;Palombo et al 2014). Knowledge of carbon dynamics (Montagnoli et al 2012b) is crucial when addressing issues relating to carbon accounting, including quantifying carbon for credit schemes (Patenaude et al 2004;Kim et al 2009).…”

Progressive Succession at Vegetation of Gölardı (Terme/Samsun) Natural Protected Area

“…Likewise, for the species belonging to early successional stage the content of the organic matter does not make any difference for germination, whereas the species that belong to late successional stage prefer soils with high organic matter content [41]. In addition, it has been determined that, since there is an interaction between soil moisture and soil temperature, water table level has an effected on the growth of root hair of woody species [42]. One of the most important charasteristics of early stage of psammoseral succession is that it is poor in terms of the nutrients of the habitat.…”