Abstract• The resorption of nutrients (mainly N and P) from senescing leaves may be a key component of adaptive mechanisms that conserve scarce nutrients. Resorption may be expressed in two ways as resorption efficiency (RE) which is the ratio of the resorbed amounts of nutrient losses during leaf senescence in relation to its prior amount deposited in leaves and resorption proficiency (RP) is the level to which nutrient concentration per unit leaf mass is reduced in senescent leaves.• There is still much debate whether or not different life-forms (i.e. deciduous and evergreen species) show different foliar resorption patterns. Two sympatric species, namely Quercus petraea (Mattuschka) Liebl. subsp. iberica (Steven ex Bieb.) Krassiln. (deciduous) and Arbutus andrachne L. (evergreen) along an elevational gradient were compared with each other to determine whether or not nitrogen and phosphorus resorption efficiency and proficiency varies along the elevational gradient and which leaf parameters were as related to RE and RP.• NRE was found to be rather low in Q. petraea subsp. iberica compared to other deciduous species. Similarly, PRE in A. andrachne was rather low compared to other evergreen species. Mean residence time (MRT) measures how long a unit of nitrogen (MRT N ) and phosphorus (MRT P ) is present in the plant. MRT N and MRT P were found to be considerably higher in A. andrachne compared to Q. petraea subsp. iberica. In both species, the foliar N/P ratio was below 14 along the elevational gradient and, according to this threshold value, N-limitation occurred in the study area. Although both species in the present study show incomplete resorption deciduous species was more proficient as compared to evergreen one due to low N and P concentrations in senescent leaves. Based on the significant correlations (p < 0.05 and 0.01) between MRT and foliar resorption, it can be concluded that MRT could interfere with the mechanisms controlling nutrient resorption.Mots-clés : stratégies de Grime / temps moyenne de résidence (MRT) / rapport N/P / efficience de la résorption / capacité de résorption / espèces sympatriques Résumé -Résorption foliaire chez Quercus petraea subsp. iberica et Arbutus andrachne le long d'un gradient altitudinal.• La résorption des éléments nutritifs (essentiellement N et P) par sénescence des feuilles peut être une composante clé des mécanismes d'adaptation qui permettent de conserver les rares éléments nutritifs. La résorption peut être exprimée de deux façons : l'efficience de résorption (RE) qui est le rapport entre la quantité résorbée des pertes d'éléments nutritifs au cours de la sénescence des feuilles par rapport à son montant déposé auparavant dans les feuilles et la capacité de résorption (RP) qui est le niveau auquel la concentration des éléments nutritifs par unité de masse de feuilles est réduite dans les feuilles sénescentes.• Il reste encore beaucoup de débat pour déterminer si les différentes formes de vie (c'est-à-dire les espèces décidues et les espèces sempervirentes) prése...

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The main aim of this study was to compare Grime's strategies in 91 plant taxa occurring from the eastern to the western part of the central Black Sea region of northern Turkey (Samsun). To do this, 45 sample plots were taken from different community types (from swamp forests to halophytic communities), and the strategies of plant species were compared with each other. Many tree and shrub species present in Hacı Osman Forest, a protected swamp forest, exhibited a purely competitive (C) strategy; some other tree and shrub species exhibited secondary strategies such as competitive/competitive stress-tolerant (C/CS) and competitive/competitive ruderal (C/CR). The ecological features of Hacı Osman Forest and Galeriç Forest are similar, and species of either forest tended to adopt stress-tolerant strategies. Coastal dune species within the study area exhibited transient strategies. Finally, it was evaluated that the CSR classification model can be successfully applied to determine the responses of plant species to changing land use patterns and disturbance factors, even for woody shrub and tree species, although our data were not entirely consistent with Grime's succession theory.

Lichens have been widely used in biomonitoring studies. In this study, Cd, Cu, Pb and Zn concentrations in some foliose and fruticose lichens which are found in Samsun were investigated and the differences among the species in terms of trace element concentrations and possible interactions among heavy metals were also examined. The results of the present study show that the study area is polluted by Pb and Cd. The cadmium contamination levels were also higher than those of the other elements. The highest Pb (101.39 ppm), Cu (43 ppm) and Zn (67.60 ppm) levels were found in Physcia adscendes. In addition to this, Hypogymnia physodes is one of the foliose species and the best accumulator of Cd (245.73 ppm) as compared to the other species. Samsun Ýlinde Ýz Element Konsantrasyonlarýnýn Likenler Kullanýlarak Biyolojik Olarak Belirlenmesi ÖzetLikenler biyomonitör çalýþmalarýnda yaygýn olarak kullanýlýrlar. Bu çalýþmada, Samsun ilinde yayýlýþ gösteren bazý yapraksý (foliose) ve dalsý (fruticose) likenlerde Cd, Cu, Pb ve Zn konsantrasyonlarý ve iz element konsantrasyonlarý açýsýndan türler arasýndaki farklýlýklar ve aðýr metaller arasý muhtemel etkileþimler incelendi. Mevcut çalýþmanýn sonuçlarý çalýþma alanýnýn Pb ve Cd tarafýndan kirlendiðini gösterdi. Kadmiyum kirliliði seviyeleri diðer elemetlerinkinden yüksektir. En yüksek Pb (101.39 ppm), Cu (43 ppm) ve Zn (67.60 ppm) seviyeleri Physcia adscendes'de bulundu. Buna ilave olarak, yapraksý türlerden birisi olan Hypogymnia physodes diðer türler ile karþýlaþtýrýldýðýnda en iyi Cd (245.73 ppm) biriktiren türdür.

Materials and methods Study area, sampling, and chemical analysisThree swamp forests were studied in the Central Black Sea region of Turkey (Figure 1). The first forest, known as Hacı Osman Forest (41°18′N, 36°55′E), covers approximately Abstract: Ellenberg developed a system that assigns indicator scores for habitat characteristics of individual plant species. Swamp forests are highly diverse ecological communities and include different plant species, all of which have different ecological requirements. Ellenberg's indicator values (EIVs) were calculated for soil pH and nitrogen (N) concentration in some swamp forest species in the Central Black Sea region of Turkey. In this study, the EIVs for soil pH were usually similar in the swamp forest species studied, while some differences were found with respect to EIVs for soil nitrogen concentration. Tolerance values (TVs) of all of the studied species were higher than those reported in similar studies because EIVs and species abundance were high in the present study compared to similar studies. TVs (soil pH) were higher in Galeriç Forest than in the other 2 swamp forests. The differences among the swamp forest species studied with respect to EIVs might be explained on the basis of soil heterogeneity, even on a local scale.