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Optimal nitrogen availability is necessary to keep high photosynthetic efficiency and in consequence, good physiological condition and growth of plants. In order to examine the effect of N nutrition on photosynthetic apparatus performance we used the chlorophyll a fluorescence (ChF) technique in two differing Actinidia cultivars and we aimed to select the most reliable ChF parameters showing N deficiency. The 4-years-old specimens growing on an experimental plantation were treated with three differing N doses and ChF data were collected during two years. The results showed that PSII performance indices, performance index on the absorption basis and total performance index, are useful to detect the overall decrease in photosynthetic apparatus vitality. Efficiency of electron movement beyond QA into the electron transport chain was more susceptible to different N nutritions than maximum quantum efficiency, while a pool of QA reducing reaction centres per PSII antenna chlorophyll, RC/ABS, and a number of QA reducing reaction centres per cross section of a sample, RC/CS0, were the best indicators of N deficiency.

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Tree pruning is carried out to reduce conflict with infrastructure, buildings, and any other human activity. However, heavy pruning may result in a diminished tree crown capacity for sugar production and exposure to fungal infection. This risk leads to a decrease in tree stability or vigour. In this work, we analysed the effect of heavy pruning of roadside trees on the photosynthetic performance process compared to neighbouring unpruned trees. Four years of tree crown growth was studied by terrestrial imaging. Tree vitality (Roloff’s classification) and risk (Visual Tree Assessment) were evaluated. Over-pruned trees showed intensified photosynthetic efficiency during the growing season following pruning. Particularly ET0/TR0 and PIABS tended to increase in pruned trees while higher Fv/Fm was noted only in late October, suggesting delayed leaf senescence. After four years, pruned trees rebuilt their crowns, however not in their entirety. Results obtained from biometric, vitality, and risk assessment showed high differentiation in pruned tree crown recovery. Our results revealed that despite the intensified efforts of trees to recover from wounding effects, severe pruning evokes dieback occurrence and a higher risk of failure in mature trees.

Chlorophyll a fluorescence (ChF) signal analysis has become a widely used and rapid, non-invasive technique to study the photosynthetic process under stress conditions. It monitors plant responses to various environmental factors affecting plants under experimental and field conditions. Thus, it enables extensive research in ecology and benefits forestry, agriculture, horticulture, and arboriculture. Woody plants, especially trees, as organisms with a considerable life span, have a different life strategy than herbaceous plants and show more complex responses to stress. The range of changes in photosynthetic efficiency of trees depends on their age, ontogeny, species-specific characteristics, and acclimation ability. This review compiles the results of the most commonly used ChF techniques at the foliar scale. We describe the results of experimental studies to identify stress factors that affect photosynthetic efficiency and analyse the experience of assessing tree vigour in natural and human-modified environments. We discuss both the circumstances under which ChF can be successfully used to assess woody plant health and the ChF parameters that can be useful in field research. Finally, we summarise the advantages and limitations of the ChF method in research on trees, shrubs, and woody vines.

De-icing salts are harmful for roadside greenery. The aim of our study was to examine photosystem II performance in mature trees growing along a road of heavy traffic in relation to shoot and soil salinity caused by de-icing salts. Leaves from each three specimens of Aesculus hippocastanum, Tilia cordata, and Betula pendula growing along the same road, nine leaves from a roadside part (RS) and nine from an opposite part (OS) of each tree crown, were sampled in June, July, and September, 2017 and 2018. The PSII performance in RS and OS leaves was compared using chlorophyll a fluorescence (ChF) technique. Since the beginning of the both growing seasons, several parameters of ChF were different in OS and RS leaves, especially maximum quantum yield of primary photochemistry and efficiency of electron movement beyond plastoquinone QAmarkedly decreased in RS leaves. However, PSII performance was not directly bound to shoot/ soil salinity.

The term “fortress landscape” is a holistic one which involves coverage and terrain adapted for defensive purposes. The specificity of the historical heritage of the Polish cultural landscape is expressed in a great number of such objects, some of which have been absorbed by its cities. A case in point is the Warsaw Fortress. A significant part of its fortification has survived to this day. Due to its spatial structure, manner of use and condition, the Fortress constitutes a valuable element of Warsaw’s natural system. At the same time, it should be noted that this element is important due to being a tourist attraction and is an example of qualified military tourism. Military tourism is one of the most popular types of modern tourism. Its elements are frequently integrated into the urban green area system. Moreover, due to its specific spatial structure, the Fortress provides a unique element enriching the cultural landscape of the city. In this paper, a historical background of the Warsaw Fortress is analyzed with a special emphasis on its cultural value and public perception. The methods used in the study include a cultural value assessment, the WNET method, a survey questionnaire and both PCA and PCC statistical methods. The analysis showed that the landscape value of the Fortress received 70% of the maximum possible rating in the conducted survey. What is more, the Warsaw Fortress was also evaluated using all the assessment criteria. The study shows that the entry of the fortress elements into the city’s natural system is perceived as being valuable, although it often lacks a specific program. Consequently, the Warsaw Fortress should be subject to landscape protection with a view towards revitalization, along with introducing a recreational program.

In the last years, JIP-test became to be a tool widely applied to assess the performance of photosynthetic apparatus of plants growing under environmental stresses. The objective of our work was to check whether JIP-test can help to predict winter survival in plants. An experiment with outdoor vertical garden was conducted in June 2015 on a south-oriented wall in Lublin city, Poland. Plants were cultivated in pockets made of polyester felt and irrigated by automatic controlled system. After winter period (2015/2016) only 16 species and cultivars from 23 initially planted taxa substantiated successful survival. Chlorophyll fluorescence measurements were performed twice in 2015 and six times in 2016. Survival rate of examined species did not show any significant correlation with performance indices of PSII (PIABS and PItotal) and parameters related to quantum yields. On the other hand, changes of some parameters related to specific energy fluxes per active reaction centres were found to be connected, to some extent, to plants winter survival. These changes could play a key role in plants ability to survive winter conditions.