Fine-root longevity of Quercus ilex

López B., Sabaté S., Gracia C.A. (2001) Fine-root longevity of Quercus ilex. New Phytologist. 151: 437-441.
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Doi: 10.1046/j.0028-646X.2001.00189.x

Resum:

Fine-root longevity and phenology were studied in a Quercus ilex (holm oak) forest in Prades (NE Spain). Differences were investigated among roots that had appeared in different seasons and at different depth intervals, differentiating between white and brown roots. Using minirhizotrons installed in March 1994, 1211 roots were monitored every 3 wk from June 1994 to March 1997. Mean and median fine-root longevity were 125 ± 4 d and 67 d, respectively. Longevity of summer and winter roots was greater than that of spring and autumn roots. Although roots appeared and disappeared throughout the year, the rate of appearance was greatest in spring. Maximum longevity occurred at a soil depth of 20-30 cm. Differences among 10-cm depth intervals were due to the number of days that roots were brown, since roots remained white for a similar number of days, independent of soil depth. Temperate soil temperatures and lignotubers permitted the appearance of roots throughout the year. Holm oak fine roots might be more efficient during the first 50 d of their life before the white roots become less efficient brown roots. © New Phytologist (2001).

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Annual and seasonal changes in fine root biomass of a Quercus ilex L. forest

López B., Sabaté S., Gracia C.A. (2001) Annual and seasonal changes in fine root biomass of a Quercus ilex L. forest. Plant and Soil. 230: 125-134.
Enllaç
Doi: 10.1023/A:1004824719377

Resum:

The biomass, production and mortality of fine roots (roots with diameter <2.5 mm) were studied in a typical Mediterranean holm oak (Quercus ilex L.) forest in NE Spain using the minirhizotron methodology, A total of 1212 roots were monitored between June of 1994 and March of 1997. Mean annual fine root biomass in the holm oak forest of Prades was 71 ±8 g m-2 yr-1. Mean annual production for the period analysed was 260+11 g m-2 yr-1. Mortality was similar to production, with a mean value of 253±3 g m-2 yr-1. Seasonal fine root biomass presented a cyclic behaviour, with higher values in autumn and winter and lower in spring and summer. Production was highest in winter, and mortality in spring. In summer, production and mortality values were the lowest for the year. Production values in autumn and spring were very similar. The vertical distribution of fine root biomass decreased with increasing depth except for the top 10-20 cm, where values were lower than immediately below. Production and mortality values were similar between 10 and 50 cm depth. In the 0-10 cm and the 50-60 cm depth intervals, both production and mortality were lower.

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