The Bialowieza Primeval Forest (BF) is one of the well-known forests in Central Europe. The most common tree species in BF was Norway spruce (Picea abies (L.) H. Karst), comprising 26%. However, a mass dieback of spruce has occurred during recent years. The spruce dieback in Bialowieza Forest is directly caused by the spruce bark beetle. However, the mass appearance of this pest can be a consequence of global warming and drought. Changes in air temperature were presented and drought indices were calculated as follows: standardized precipitation index, Palmer drought severity index, climatic water balance and soil water storage deficit. The warming of the climate of Bialowieza from 1950 to 2015 is comparable to that observed throughout central Europe. The temperature increased by 1.27 °C. The occurrence of drought from 1950 to 1966 and from 1985 to 2015 had a similar frequency. From 1963 to 1966, the volume of removed deadwood from the managed part of Bialowieza Forest was 27 thousand m³ but from 2012 to 2016, the volume was more than one million m³.

Viscum album L. is a plant of great importance due to its influence on the host trees and, by extension, entire ecosystems. The species is also significant to humans—on the one hand, because of its use in medicine, and on the other, because of the growing threat it poses to the stability of conifer stands. Therefore, it is important to recognize the future range of three mistletoe subspecies (Viscum album subsp. album, V. album subsp. austriacum, and V. album subsp. abietis). Modelling of the potential range of these subspecies was performed using MAXENT software. Locations were collected from literature and databases. A total number of 3335 stands were used. Bioclimatic data for the current conditions and three future scenarios (SSP 1.26, SSP 3.70, SSP 5.85) were downloaded from the CHELSA database. The results confirmed that the temperature is the key variable on the potential range of the analysed subspecies. V. album subsp. abietis is withdrawing from its range according to all scenarios. In the case of V. album subsp. austriacum, a slight range shift is visible. Only the V. album subsp. album will expand non-directionally. The reason is most likely a very large number of host species and greater genetic variability compared to the subspecies found on conifers.

Highly accurate and extensive datasets are needed for the practical implementation of precision forestry as a method of forest ecosystem management. Proper processing of huge datasets involves the necessity of the appropriate selection of methods for their analysis and optimization. In this paper, we propose a concept for and implementation of a data preprocessing algorithm, and a method for the empirical verification of selected individual tree detection (ITD) algorithms, based on Airborne Laser Scanning (ALS) data. In our study, we used ALS data and very extensive dendrometric field measurements (including over 21,000 trees on 522 circular sample plots) in the economic and protective coniferous stands of north-eastern Poland. Our algorithm deals well with the overestimation problems of tree top detection. Furthermore, we analyzed segmentation parameters for the two currently dominant ITD methods: Watershed (WS) and Local Maximum Filter with Growing Region (LMF+GR). We optimized them with respect to minimizing the Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE). Additionally, our results show the crucial importance of the quality of empirical data for the correct evaluation of the accuracy of ITD algorithms.

Puszcza Białowieska uważana jest za jeden z najcenniejszych kompleksów leśnych w Europie, a tymczasem opublikowane informacje o jej pokrywie glebowej pochodzą z lat 60-tych i to wyłącznie z obszaru Parku Narodowego. Celem artykułu jest analiza właściwości i zróżnicowania gleb rdzawych na podstawie wyników prac siedliskowych przeprowadzonych w nadleśnictwach Białowieża, Hajnówka i Browsk, tworzących Leśny Kompleks Promocyjny Puszcza Białowieska otaczający Białowieski Park Narodowy. Dominacja piaszczystych utworów macierzystych (zlodowacenia Warty) sprzyja powszechnemu występowaniu gleb rdzawych, zajmujących ok. 39% powierzchni. Przestrzenna różnorodność tych utworów (piaski zwałowe, wodnolodowcowe, eoliczne i wydmowe, piaski pokrywowe na glinach i in.), a także częsta obecność przewarstwień oraz podłoży drobno- i gruboziarnistych, sprzyjają wykształceniu gleb rdzawych we wszystkich podtypach (brunatnych, właściwych i bielicowych). Choć gleby rdzawe badanego obszaru odznaczają się silnym zakwaszeniem profilu, niską zawartością kationów wymiennych i niskim wysyceniem kationami, właściwości te wyraźnie różnicują się pomiędzy podtypami, skutkując najwyższą troficznością gleb rdzawych brunatnych i najniższą – rdzawych bielicowych. Na zróżnicowanie właściwości fizykochemicznych w profilach oraz pomiędzy podtypami gleb rdzawych oddziałuje nie tylko rodzaj utworu macierzystego (wpływ na uziarnienie i suma kationów), ale też – bezpośrednio lub pośrednio - porastająca roślinność/drzewostan (wpływ na zawartość węgla organicznego i azotu, kwasowość hydrolityczną, pH, wysycenia kationami zasadowymi). Oznacza to, że skład gatunkowy lasu, lub szerzej, gospodarka leśna może znacząco wpływać na kierunek i intensywność transformacji gleb. Zróżnicowaniu troficznemu podtypów gleb rdzawych odpowiada zróżnicowanie dominujących na tych podtypach kategorii żyzności siedlisk: lasu/lasu mieszanego na glebach rdzawych brunatnych, lasu mieszanego na rdzawych właściwych oraz boru mieszanego na glebach rdzawych bielicowych. Podtypy gleb rdzawych wyróżnione według Klasyfikacji gleb leśnych Polski korelują z ich analogami w Systematyce gleb Polski (wydanie 6), tj. glebom rdzawym brunatnym, właściwym i bielicowym odpowiadają odpowiednio gleby rdzawo-brunatne, rdzawe typowe i rdzawe zbielicowane. Zastosowanie Systematyki umożliwiłoby jednoznaczną klasyfikację gleb o cechach przejściowych (np. gleb rdzawo-brunatnych zbielicowanych) oraz podniosło rangę klasyfikacyjną niektórych gleb z oglejeniem gruntowym, węglanami oraz gleb porolnych.

In this study, we analyzed the change in tree height of 2594 Scots pine (Pinus sylvestris L.) trees with respect to the distribution among different forest sites: HCfs—hydrogenic coniferous forest site; MCfs—mineral coniferous forest site; MMfs—mineral mixed forest site. We obtained tree height information from three independent airborne laser scanning (ALS) point clouds acquired in north-eastern Poland over a 5-year interval in 2007, 2012, and 2017 using verified tree crown segments. We performed a comparative analysis of digital terrain models (DTMs) calculated from analyzed point clouds, indicating that the highest elevation differences were observed in the case of data from 2007. The analyses showed that tree growth varies significantly depending on the forest site productivity and the stage of tree development, which was described as initial tree height instead of age—commonly used in such studies. In conclusion, it is possible to indicate the significant information potential of using multitemporal ALS data to track individual tree height changes. These field data, combined with meteorological data, can be successfully used to predict changes in the abundance of stands depending on the forest site productivity. We have built Scots pine growth models for each forest site, which indicates that it is possible to predict the change in the tree stand height.

In Central Europe, deforestation led to a reduction of forest area by almost 80%, compared to the original area, by the beginning of the 20th century. At this point in time, a period of intensive reforestation began in an effort to restore forest areas. This process of reforestation, especially on post-agricultural land, continues to this day. This article examines reforestation and natural regeneration on former farmland and the factors that influence the current state as well as the future growth of the forest. Ancient and contemporary views on the functioning of stands on post-agricultural land created by both, natural and forced succession (i.e. afforestation), are recalled. In Poland, this issue primarily concerns managed state forests, which cover an area of over 2 million hectares. We discuss the differences in the development of these stands resulting from the history of agricultural cultivation, the type of afforestation, the influence of environmental factors as well as biotic threats to their development. Furthermore, the need to change the silviculture-, protection- and endowment-based approach to forest management in stands on post-agricultural land is highlighted.