Foliar nitrogen and phosphorus resorption in an undisturbed and a Pinus pinaster Ait. planted forests in northern Turkey

Abstract

résorption foliaire de l'azote et du phosphore dans une forêt non perturbée et dans une forêt plantée de Pinus pinaster ait. dans le nord de la turquie. -La résorption foliaire est étroitement liée à la sénescence et à la conservation des nutriments et protège la plante dans sa dépendance des apports du sol. Dans la présente étude, ont été étudiées dans le nord-est de la Turquie la dynamique foliaire de l'azote (N) et du phosphore (P), l'efficacité (RE) et la profitabilité (RP) de la résorption foliaire de quelques plantes décidues existant dans une forêt non perturbée et dans une autre plantée en Pinus pinaster Ait. En forêt non perturbée, on n'a pas observé de différences entre les espèces pour ce qui concerne l'efficacité et la profitabilité alors qu'en forêt plantée en P. pinaster des différences statistiquement significatives ont été notées entre les espèces pour ce qui concerne la NRE, la NRP et la CRE. La CRE est apparue plus élevée que chez les angiospermes et graminoïdes ligneux sempervirents présents dans la zone d'étude. La NRE était plus forte en forêt non perturbée qu'en forêt plantée en P. pinaster. Dans les deux forêts la résorption foliaire de l'azote et du phosphore était biochimiquement complète. Il a été trouvé que la limitation en phosphore se produisait dans les plantes décidues des deux forêts au niveau des rapports N/P durant la sénescence foliaire. De même, le rapport C/N s'est avéré élevé durant la sénescence. En forêt plantée en P. pinaster le rapport N/P et la NRE (tant en masse qu'en surface) sont apparus plus faibles qu'en forêt non perturbée.SUmmARY. -Foliar resorption is closely associated with leaf senescence and conservation of nutrients, and protects the plant dependence on soil supply. In this study, leaf nitrogen (N) and phosphorus (P) dynamics, leaf resorption efficiency (RE) and resorption proficiency (RP) in some deciduous plants occurring in an undisturbed forest and a Pinus pinaster Ait. planted forest were investigated in northeastern Turkey. There were no significant differences among species with respect to foliar resorption efficiency and proficiency in undisturbed forest, whilst statistically significant differences were found among species regarding NRE, NRP and CRE in P. pinaster planted forest. CRE was found to be higher than for evergreen woody angiosperms and graminoids present in the study area. NRE was higher in undisturbed forest than in P. pinaster planted forest. In both forests foliar nitrogen and phosphorus resorption were biochemically complete. It was found that phosphorus limitation occurred in deciduous plants in both forests with respect to N/P ratios during leaf senescence. Similarly, C/N ratio was found to be high during senescence. In P. pinaster planted forest N/P ratio and NRE (both mass-and area-based) were found to be low as compared to undisturbed forest.Forests and tree plantations are increasingly considered for their central role as providers of habitat and regulators of global biogeochemical, temperature and water cycles. Forest

Nitrogen and phosphorus resorption in some sympatric plant species in the North of Turkey

“…Leaf P compounds is readily resorbed, while resorption of leaf N compounds is a bit slow and PRE is of great importance with respect to nutrient use efficiency (Aerts & Chapin, 2000;Covelo et al, 2008;Salazar et al, 2011;Yilmaz et al, 2014). Our study area is severely P-limited and it has been reported that species growing in P-limiting conditions would be more favoured by high resorption efficiency and that in P-poor soils phosphorus is more limiting than nitrogen (Covelo et al, 2008;Kilic et al, 2012;Miatto et al, 2016). It has also been stated that limiting nutrients are usually more resorbed than non-limiting ones and species on infertile soils rely more on foliar resorption as compared to species on fertile soils (Yilmaz et al, 2014;Brant & Chen 2015;Miatto et al, 2016).…”

Foliar resorption of some macro-(N, P, S) and micronutrients (Fe, Zn, Cu, Mn) in Pterocarya fraxinifolia (Poiret) Spach forests in Turkey

“…Reed et al (2012) stated that if NRE/PRE ratios were < 1 more P was consistently resorbed relative to N. It has been found that PRE was higher as compared to NRE in southern populations. Several authors implied that P compounds in a leaf are more readily resorbed as compared to N compounds therefore PRE is more significant with respect to nutrient use efficiency than NRE (Aerts & Chapin, 2000;Salazar et al, 2011;Yilmaz et al, 2014). However, the opposite trend was found in northern populations and NRE was higher than PRE.…”

“…Resorption can be expressed as resorption efficiency (RE) and resorption proficiency (RP) respectively. RE is defined as the percentage of a nutrient recovered from a senescing leaf (Kilic et al, 2010;Yilmaz et al, 2014). RP is known as the amount of a particular nutrient that remains in fully senesced leaves and is not subject to temporal variation in nutrient concentration in green leaves or the timing of sampling (Killingbeck, 1996(Killingbeck, , 2004.…”

“…There were many studies on foliar macroelement especially nitrogen (N) and phosporus (P) resorption in temperate deciduous forests (Kilic et al, 2010;Covelo et al, 2011;Yilmaz et al,. 2014;Surmen et al, 2014).…”

“…Macro-and micronutrient resorption efficiency (NRE, PRE, FeRE, ZnRE, CuRE, MnRE, and SRE) (%) was calculated as the percentage of macro-and micronutrients recovered from senescing leaves and calculated by RE = (macro-or micronutrient in mature greenmacro-or micronutrient in senescent) / macro-or micronutrient in mature green × 100 %, where: macro-or micronutrient in mature green = macro-or micronutrient in mature green leaves, macro-or micronutrient in senescent = macroor micronutrient in senescent leaves (Killingbeck, 1985;Kilic et al, 2010). MLCF is defined as the ratio of dry mass of senesced leaves to the dry mass of green leaves (Yilmaz et al, 2014). Foliar resorption was also calculated by accounting mass loss correction factor (MLCF) by the help of following equation:…”