Fine‐root morphological and growth traits in a Turkey‐oak stand in relation to seasonal changes in soil moisture in the Southern Apennines, Italy

Abstract

We investigated the effects of seasonal changes\ud in soil moisture on the morphological and growth traits\ud of fine roots (<2 mm in diameter) in a mature Turkeyoak\ud stand (Quercus cerris L.) in the Southern Apennines\ud of Italy. Root samples (diameter: <0.5, 0.5–1.0, 1.0–1.5,\ud and 1.5–2.0 mm) were collected with the Auger method.\ud Mean annual fine-root mass and length on site was\ud 443 g m!2 (oak fine roots 321 g m!2; other species\ud 122 g m!2) and 3.18 km m!2 (oak fine roots 1.14 km\ud m!2; other species 2.04 km m!2), respectively. Mean\ud specific root length was 8.3 m g!1. All fine-root traits\ud displayed a complex pattern that was significantly related\ud to season. In the four diameter classes, both fineroot\ud biomass and length peaked in summer when soil\ud water content was the lowest and air temperature the\ud highest of the season. Moreover, both fine-root biomass\ud and length were inversely related with soil moisture\ud (p < 0.001). The finest roots (<0.5 mm in diameter)\ud constituted an important fraction of total fine-root\ud length (79 %), but only 21 % of biomass. Only in this\ud root class, consequent to change in mean diameter,\ud specific root length peaked when soil water content was\ud lowest showing an inverse relationship (p < 0.001).\ud Furthermore, fine-root production and turnover decreased\ud with increasing root diameter. These results\ud suggest that changes in root length per unit mass, and\ud pulses in root growth to exploit transient periods of low\ud soil water content may enable trees to increase nutrient\ud and water uptake under seasonal drought conditions

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).…”

Characteristics of Fine Roots of Pinus massoniana in the Three Gorges Reservoir Area, China

“…Studies have also shown that 30-80% of forest soil organic C is derived from the turnover and decomposition of fine root biomass [13,16,17], and it is generally accepted that fine roots are components within the overall root system sensitive to rooting environmental variations [18,19]. For example, fine root responses to changes in soil moisture are diameter dependent [20] and the morphological characteristics and biomass of very fine roots (diameter < 0.5 mm) are affected differently by changes in soil warming [21] and soil Ca content [22]. It has been demonstrated that root life span is also affected by soil properties [23,24].…”

Short-Term Effects of Low Intensity Thinning on the Fine Root Dynamics of Pinus massoniana Plantations in the Three Gorges Reservoir Area, China

“…In addition, FRB shows obvious seasonal dynamics and has a significant seasonal pattern [13]. In general, FRB has unimodal or bimodal variations throughout the year [14][15][16], with the maximum value often occurring in mid to late summer, and the minimum value in late autumn to early winter [17,18]. Many studies have shown that the biomass of the fine roots of P. massoniana often shows only one peak, although the timing thereof varies, under natural conditions [19].…”

“…Fine roots, even those that are <0.5 mm, have been shown to be extremely sensitive to environmental changes and are dependent on factors such as forest stand characteristics [14] (life form, tree species, stand age, stand density, basal area, and understory vegetation), environmental cues (soil moisture, soil temperature, precipitation, and soil nutrient availability) [14,[20][21][22][23]. However, the results of previously published studies are inconsistent.…”