A key process in forest management planning is the estimation of tree volume and, more specifically, merchantable volume. The ability to predict the cumulative stem volume relative to any upper stem diameter on standing trees or stands is essential for forest inventories and the management of forest resources. In the 1980s, the Hellenic Public Power Corporation (HPPC) started the rehabilitation of lignite post-mining areas in Greece by planting mainly black locust (Robinia pseudoacacia, L.
View Article and Find Full Text PDFAleppo pine () is widely distributed in the Mediterranean region and in other areas of the world, where it has been introduced due to its adaptive capacity to xerothermic conditions. The giant pine scale often infests Aleppo pine, as well as other pines, in several southeastern European countries, causing pine declines. When combined with the expected intensified heat and drought events in eastern Mediterranean, the impact of this biotic parameter on the host pines may be exacerbated.
View Article and Find Full Text PDFHumans require multiple services from ecosystems, but it is largely unknown whether trade-offs between ecosystem functions prevent the realisation of high ecosystem multifunctionality across spatial scales. Here, we combined a comprehensive dataset (28 ecosystem functions measured on 209 forest plots) with a forest inventory dataset (105,316 plots) to extrapolate and map relationships between various ecosystem multifunctionality measures across Europe. These multifunctionality measures reflected different management objectives, related to timber production, climate regulation and biodiversity conservation/recreation.
View Article and Find Full Text PDFThe importance of biodiversity in supporting ecosystem functioning is generally well accepted. However, most evidence comes from small-scale studies, and scaling-up patterns of biodiversity-ecosystem functioning (B-EF) remains challenging, in part because the importance of environmental factors in shaping B-EF relations is poorly understood. Using a forest research platform in which 26 ecosystem functions were measured along gradients of tree species richness in six regions across Europe, we investigated the extent and the potential drivers of context dependency of B-EF relations.
View Article and Find Full Text PDFAn assemblage of tree species with different crown properties creates heterogeneous environments at the canopy level. Changes of functional leaf traits are expected, especially those related to light interception and photosynthesis. Chlorophyll a fluorescence (ChlF) properties in dark-adapted leaves, specific leaf area, leaf nitrogen content (N) and carbon isotope composition (δ13C) were measured on Picea abies (L.
View Article and Find Full Text PDFSymbiotic nitrogen fixation (SNF) involves global changes in gene expression and metabolite accumulation in both rhizobia and the host plant. In order to study the metabolic changes mediated by leaf-root interaction, photosynthesis was limited in leaves by exposure of plants to darkness, and subsequently gene expression was profiled by real-time reverse transcription-PCR (RT-PCR) and metabolite levels by gas chromatography-mass spectrometry in the nodules of the model legume Lotus japonicus. Photosynthetic carbon deficiency caused by prolonged darkness affected many metabolic processes in L.
View Article and Find Full Text PDFBackground And Aims: Phenolic compounds are the most commonly studied of all secondary metabolites because of their significant protective-defensive roles and their significant concentration in plant tissues. However, there has been little study on relationships between gas exchange parameters and the concentration of leaf phenolic compounds (total phenolics (TP) and condensed tannins (CT)) across a range of species. Therefore, we addressed the question: is there any correlation between photosynthetic capacity (A(max)) and TP and CT across species from different ecosystems in different continents?
Methodology: A plethora of functional and structural parameters were measured in 49 plant species following different growth strategies from five sampling sites located in Greece and Australia.
During symbiotic nitrogen fixation (SNF), the nodule becomes a strong sink for photosynthetic carbon. Here, it was studied whether nodule dark CO(2) fixation could participate in a mechanism for CO(2) recycling through C(4)-type photosynthesis. Differences in the natural δ(13)C abundance between Lotus japonicus inoculated or not with the N-fixing Mesorhizobium loti were assessed.
View Article and Find Full Text PDFTree and shrub species can be differentiated into two major groups based on their substantially different leaf anatomy: heterobaric and homobaric. In contrast to homobaric leaves, heterobaric leaves have bundle sheath extensions (BSEs) that create transparent regions on their lamina. Recent studies have shown that BSEs transfer visible light to internal mesophyll layers, thus affecting the photosynthetic performance of heterobaric leaves.
View Article and Find Full Text PDFThe potential negative influence of competition from early successional species like blackberry (Rubus fruticosus) may be decisive for the natural regeneration success of drought-sensitive beech (Fagus sylvatica), especially in the light of climate change. With a split plot glasshouse experiment, we investigated the influence of two air temperature and irradiance levels on the competitive interference of blackberry on the water, nitrogen (N) and carbon (C) balance of beech seedlings under moderate drought. When increased temperature was accompanied by low irradiance the biomass, root-to-shoot ratio, N uptake and assimilation rates of blackberry were lower compared with beech, either grown alone or with blackberry.
View Article and Find Full Text PDF• Here, the effects were assessed of local climate and canopy thinning on the carbon isotope composition (δ C) signatures of different plant groups in the understorey of a beech (Fagus sylvatica) forest in southern Germany. The relationship between δ C and environmental parameters, within different time integrals, was also studied. • δ C was analysed in different tissues of beech regeneration, and herbaceous and woody understorey vegetation, in thinned and untreated control stands differing in aspect and, hence, local climate, on three dates during the growing season.
View Article and Find Full Text PDFSeasonal dynamics of net photosynthesis (Anet) in 2-year-old seedlings of Pinus brutia Ten., Pinus pinea L. and Pinus pinaster Ait.
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