Seasonal variation in nutrient concentration in leaves and branches of Quercus pyrenaica

Abstract

Abstract. Seasonal variation in nutrient concentration in leaves and branches of Quercus pyrenaica was studied in natural Q. pyrenaica forest in the Sierra de Gata (Salamanca Province, Spain). Two permanent plots were established at the two extremes of a rainfall gradient in this area: annual mean precipitation from 720 mm at Fuenteguinaldo (granite bedrock) to 1580 mm at Navasfrias (schists and graywackes). Leaf and branch samples were collected every three weeks during the growing season from May to October, at three height levels of the tree canopy. Seasonal changes and internal nutrient dynamics were investigated for N, Ca, Mg, K, Na, Mn, Fe and P during a two‐year period. The concentrations of all nutrients varied among the seasons; these variations were related to nutrient mobility and the annual physiological cycle. Nutrient concentrations decrease in the case of K and P, while the sparse mobile nutrients Ca, Mg, Mn and Fe gradually accumulated during each growing season. In Navasfrias a considerable resorption of P from senescing leaves was detected. Different patterns were found for the other nutrients studied (Na and N).

Heavy Metals Content in Foliar Litter and Branches of Quercus petraea (Matt.) Liebl. and Quercus robur L. Observed at Two ICP Forests Monitoring Plots

“…Considering the time frame of sample collection (i.e. end of the growing season), the results obtained in this study are in accordance with the findings of Santa Regina et al [24]. Namely, the authors continually reported seasonal accumulation of these two elements in the leaves of Quercus pyrenaica, whereas only slight increase in accumulation, but not statistically significant, was observed to have occurred in the branches.…”

“…Previous studies demonstrated that HMs content within Quercus genus is species-and organ-dependent [22,23], although environmental conditions [5] and tree lifetime have certain effects on HMs accumulation as well [24]. Since HMs content in two oak species occurring at separated sites and, therefore, growing under different environmental conditions was examined, direct comparison of absolute values of HMs content in their organs was not possible.…”

Rapid Leaf Deployment Strategies in a Deciduous Savanna

“…The high nitrogen demands of deciduousness, the low average nitrogen availability, and the seasonal pattern of nitrogen and water availability in the study system imply that nitrogen conservation may be important. Deciduous trees can conserve nitrogen through nutrient resorption or the withdrawal of nutrients from senescing leaves and the storage of these nutrients in woody parts [ 20 – 23 ]. Many savanna trees deploy new leaves, just before the rains, using these stored resources [ 24 – 26 ].…”

Stoichiometric and nutrient resorption characteristics of dominant tree species in subtropical Chinese forests

“…Zhang's experiments in Karst regions (Zhang et al, 2015) and several other studies (Davidson et al, 2007;Du, Pan, Li, Hu, & Wang, 2011;Huang et al, 2013) have indicated that foliar N:P ratios may change with succession owing to the N cycling properties recover accompanying with P limitation increases in mature forests. The stoichiometric ratios may also vary seasonally, because nutrient concentrations in leaves change with phenology, particularly in deciduous species (Regina, Rico, Rapp, & Gallego, 1997;Robert, Caritat, Bertoni, Vilar, & Molinas, 1996). However, published literatures focus more on stoichiometric change patterns on a large scale, such as in the world's temperate forests or tropical rain forests He et al, 2006He et al, , 2008McGroddy et al, 2004;Reich & Oleksyn, 2004), whereas research on stoichiometry variations with seasons and successions among different tree species in individual forest or on a small scale is less developed.…”