Continuous detection of small-scale changes in Scots pine dominated stands using dense Sentinel-2 time series

Climate change and severe extreme events, i.e., changes in precipitation and higher drought frequency, have a large impact on forests. In Poland, particularly Norway spruce and Scots pine forest stands are exposed to disturbances and have, thus experienced changes in recent years. Considering that Scots pine stands cover approximately 58% of forests in Poland, mapping these areas with an early and timely detection of forest cover changes is important, e.g., for forest management decisions. A cost-efficient way of monitoring forest changes is the use of remote sensing data from the Sentinel-2 satellites. They monitor the Earth’s surface with a high temporal (2–3 days), spatial (10–20 m), and spectral resolution, and thus, enable effective monitoring of vegetation. In this study, we used the dense time series of Sentinel-2 data from the years 2015–2019, (49 images in total), to detect changes in coniferous forest stands dominated by Scots pine. The simple approach was developed to analyze the spectral trajectories of all pixels, which were previously assigned to the probable forest change mask between 2015 and 2019. The spectral trajectories were calculated using the selected Sentinel-2 bands (visible red, red-edge 1–3, near-infrared 1, and short-wave infrared 1–2) and selected vegetation indices (Normalized Difference Moisture Index, Tasseled Cap Wetness, Moisture Stress Index, and Normalized Burn Ratio). Based on these, we calculated the breakpoints to determine when the forest change occurred. Then, a map of forest changes was created, based on the breakpoint dates. An accuracy assessment was performed for each detected date class using 861 points for 46 classes (45 dates and one class representing no changes detected). The results of our study showed that the short-wave infrared 1 band was the most useful for discriminating Scots pine forest stand changes, with the best overall accuracy of 75%. The evaluated vegetation indices underperformed single bands in detecting forest change dates. The presented approach is straightforward and might be useful in operational forest monitoring

Development of regional height growth model for Scots pine using repeated airborne laser scanning data

The rapid development of remote sensing technologies is creating unprecedented opportunities for monitoring and inventorying forest ecosystems. One advantage of remote sensing data is that it can be used to monitor and measure tree growth in near real-time, providing extremely useful data for growth modelling. This study used Aerial Laser Scanning (ALS) data from 14,920 Scots pine stands for the Katowice Regional Directorate of State Forests in southwestern Poland. We tested the possibility of calibrating a regional height growth model for Scots pine for a study area covering 754 thousands of hectares of forests. The model was validated with models developed for Scots pine using the traditional approach based on field data. Our results show that the model calibrated using remote sensing data does not differ significantly from the model calibrated using traditional field measurements from stem analysis. What is more, using a model developed from ALS data gives even better accuracy in modelling height growth than a traditional model calibrated with ground data. Our results are promising for the application of repeated ALS data to the development of regional height growth models, allowing long-term prediction of tree growth under current climatic conditions

Higher site productivity and stand age enhance forest susceptibility to drought-induced mortality

Warmer and drier conditions increase forest mortality worldwide. At the same time, nitrogen deposition, longer growing seasons and higher atmospheric $CO_{2}$ concentrations may increase site productivity accelerating forest growth. However, tree physiological studies suggest that increased site productivity can also have adverse effects, reducing adaptation to drought. Understanding such intricate interactions that might foster tree mortality is essential for designing activities and policies aimed at preserving forests and the ecosystem services they provide. This study shows how site factors and stand features affect the susceptibility of Scots pine to drought-induced stand-level mortality. We use extensive forest data covering 750,000 ha, including 47,450 managed Scots pine stands, of which 2,547 were affected by mortality during the drought in 2015-2019. We found that the oldest and most dense stands growing on the most productive sites showed the highest susceptibility to enhanced mortality during drought. Our findings suggest that increasing site productivity may accelerate the intensity and prevalence of drought-induced forest mortality. Therefore, climate change may increase mortality, particularly in old and high-productive forests. Such exacerbated susceptibility to mortality should be considered in forest carbon sink projections, forest management, and policies designed to increase resilience and protect forest ecosystems

Geomatyka w nauczaniu leśników na uczelniach rolniczych

The idea for this publication was barn in June 2015, during a meeting of Polish teachers involved with Geographic lnformation Systems. The meeting was initiated by the Department of Geoinformation, Faculty of Geographical Sciences, University of Łódź, which received a grant to organize it. The discussion and presentations from academic teachers representing various universities in Poland were very interesting and sometimes heated. it would be advisable for other educators to familiarise themselves with the aspects of GIS education among Polish geographers, foresters, surveyors and other users. The experience of Geoinformation education in Poland is still modest, so the views of people who have been involved at Polish universities with it since the 1990s should be interesting to readers. Geographic lnformation Systems (GIS) – the integration of environmental and climate issues as an important factor for economic development and quality of life – an innovative second-degree studies. Akronim GIS-E-QL: GIS for environment and quality of life. Project objectives: The main aim of the project is to start-up attractive and innovative second­ degree studies – geoinformation in mutual cooperation of the FGS and the FMCS, students education, improving the competence of academic teachers, conference organization, publishing, cooperation with practitioners and establishing contacts with partners from Norway. This aim is consistent with the “Ana lysis of the economy's demand for graduates in key field of strategy in the context of the Europe 2020” 2012 and “Strategy for development of higher education in Poland 2020”, in the field of promoting innovative courses, formed collectively with practitioners, raising awareness of the environment. Joint actions of educators and practitioners, supported the by the strengthening of university's hardware, software and spatial data, will ensure a high quality project. The existing cooperation with practitioners indicate that further training is necessary and they would like to see postgraduates in their institutions. The final beneficiaries of the project will be the students and the academical teaching staff and indirectly the economy of the region. Students who graduate will be the main recipient of the project, the next will be teaching staff who will have contact with the practices and Norwegian partners with similar interests. In broad terms the project will benefit Polish and European economy and environment.This book has been prepared within the project „Geographic Information Systems (GIS) – the integration of environmental and climate issues as an important factor of economic development and quality of life – an innovative second-degree studies” supported by a grant from Norway through the Norway Grants and co-financed by the Polish funds. (Agreement No FSS/2014/HEI/W/0114/U/0013)

Using LiDAR point clouds in active protection of forest lichen communities in "Bory Tucholskie" National Park

Zespół boru chrobotkowego (Cladonio-Pinetum) jest zbiorowiskiem wykształcającym się na suchych i ubogich w biogeny obszarach piaszczystych. Najlepiej zachowane płaty tego zbiorowiska roślinnego w Europie występują w Polsce północnej, w tym na terenie Parku Narodowego "Bory Tucholskie" (PNBT). Celem badań było określenie struktury przestrzennej wybranych drzewostanów sosnowych PNBT, w których zainicjowany został program ochronny czynnej borów chrobotkowych. Obszar badań obejmował część dwóch oddziałów leśnych PNBT z wydzieleniami: 18c, 19d, 19g, 19h, 19i, 19j i 19k. Badania przeprowadzono z wykorzystaniem lotniczego (ALS) i naziemnego (TLS) skanowania laserowego (LiDAR). Dzięki zastosowaniu technologii LiDAR możliwe było wykonanie bardzo precyzyjnego opisu struktury drzewostanów w przestrzeni 2D i 3D. W wyniku przeprowadzonych analiz określono szereg cech taksacyjnych i parametrów drzewostanów, takich jak: liczba i zagęszczenie drzew w drzewostanie, średnia odległość pomiędzy drzewami żywymi, liczba drzew martwych, pierśnicowe pole przekroju drzew żywych, zwarcie poziome koron, wskaźnik penetracji koron, wysokość górna drzew w wydzieleniu, wysokość podstawy korony drzewa, długość korony drzewa, objętość warstwy koron, powierzchnia 2D i 3D koron drzew, średni promień korony, współczynnik morfometryczny koron oraz zasięg pionowy martwych gałęzi. Opracowano także mapę występowania luk w wydzieleniach o powierzchni większej niż 2 m2. Badania rozpoczęte w 2017 roku są kontynuowane w 2018 roku z wykorzystaniem skanowania z platformy BSP (UAS) oraz TLS, które posłużą precyzyjnej ocenie zmian struktury przestrzennej drzewostanów, w których przeprowadzono cięcia prześwietleniowe.Forest lichen communities develop on dry and poor in biogens sandy areas. The center of occurrence of this plant community in Europe coincides with Natura 2000 sites located in Poland, including the Bory Tucholskie National Park (BT NP). The aim of the study was to determine the spatial structure of selected Scots pine stands of BT NP, where a program of active protection of lichen communities was initiated. The research area included two forest compartments: 18 and 19. The analysis was performed in the following sub-compartments: 18c, 19d, 19g, 19h, 19i, 19j and 19 k. The research was carried out using airborne (ALS) and terrestrial (TLS) laser scanning (LiDAR). Thanks to the use of LiDAR technology, it was possible to make a very precise description of the structure of stands in 2D and 3D space. As a result of the conducted study, a number of stand parameters have been defined, such as: number of trees, tree density in the stand, number of live trees, average distance between living trees, number of dead trees, basal area, horizontal cover of tree crowns, crown penetration ratio, average height of trees, height of the crown base, tree crown length, crown layer volume, 2D and 3D crown surface, average crown radius, canopy relief ration and vertical range of dead branches. A map of crown gaps with an area of more than 2 m2 was also developed. Research activities with the use of laser scanning technology is continued in 2018 (repeated ALS and TLS scanning). The conducted research will allow to determine the influence of the stand structure on factors influencing the occurrence of lichens, including: shaping of microclimatic conditions

GIS w polskiej edukacji wyższej – dyskusja

The idea for this publication was barn in June 2015, during a meeting of Polish teachers involved with Geographic lnformation Systems. The meeting was initiated by the Department of Geoinformation, Faculty of Geographical Sciences, University of Łódź, which received a grant to organize it. The discussion and presentations from academic teachers representing various universities in Poland were very interesting and sometimes heated. it would be advisable for other educators to familiarise themselves with the aspects of GIS education among Polish geographers, foresters, surveyors and other users. The experience of Geoinformation education in Poland is still modest, so the views of people who have been involved at Polish universities with it since the 1990s should be interesting to readers. Geographic lnformation Systems (GIS) – the integration of environmental and climate issues as an important factor for economic development and quality of life – an innovative second-degree studies. Akronim GIS-E-QL: GIS for environment and quality of life. Project objectives: The main aim of the project is to start-up attractive and innovative second­ degree studies – geoinformation in mutual cooperation of the FGS and the FMCS, students education, improving the competence of academic teachers, conference organization, publishing, cooperation with practitioners and establishing contacts with partners from Norway. This aim is consistent with the “Ana lysis of the economy's demand for graduates in key field of strategy in the context of the Europe 2020” 2012 and “Strategy for development of higher education in Poland 2020”, in the field of promoting innovative courses, formed collectively with practitioners, raising awareness of the environment. Joint actions of educators and practitioners, supported the by the strengthening of university's hardware, software and spatial data, will ensure a high quality project. The existing cooperation with practitioners indicate that further training is necessary and they would like to see postgraduates in their institutions. The final beneficiaries of the project will be the students and the academical teaching staff and indirectly the economy of the region. Students who graduate will be the main recipient of the project, the next will be teaching staff who will have contact with the practices and Norwegian partners with similar interests. In broad terms the project will benefit Polish and European economy and environment.The experience of Polish scientists and educators in the GIS has not been as long as mentioned by Michael F. Goodchild who jointly with Ross Newkirk (Goodchild 2006) started the fi rst GIS training course at the University of Western Ontario in Canada in 1975. Discussions on the scope of knowledge included in the GIS have continued at most universities that have offered such classes. In 1988/89, owing to the National Centre for Geographic Information and Analysis (NCGIA), the 3-volume document of over 1000 pages was put together to include curriculums, student materials and other teaching aids. We have good models and we can use them. Meetings and discussions about the GIS education have been and still are regularly held all over the world (Forer P., Unwin D. 1999). When employees of Polish universities were starting to learn the GIS software and possibilities, Morgan J. M., Fleury B., Becker R. A. (1996) had already identifi ed over 800 higher education institutions all over the world that had offered at least one GIS course. The rapid development of new technologies, methods, the creation of new labour markets has arisen discussions on the contents GIS training in various centres of higher education, e.g. in the Netherlands, the US, and those have been similar to the ones presented in this article (Toppen F. J. 1992) and some issues needed to be resolved in court (DiBiase, D. 2008). You can see how important these meetings of educators are for exchanging opinions and experience. They have allowed to meed people representing various fi elds involved in the geoinformation, which may result in co-operation and new educational initiatives, and sometimes, competition. Finally, we should agree with prof. J. Gaździcki (2009 p. 12) that “It is obvious that the success of any measures to modernise education in the area under consideration depends on the interest of academic communities, involvement of research and academic staff in these endeavours, their will, ambition and willingness to co-operate”.This book has been prepared within the project „Geographic Information Systems (GIS) – the integration of environmental and climate issues as an important factor of economic development and quality of life – an innovative second-degree studies” supported by a grant from Norway through the Norway Grants and co-financed by the Polish funds. (Agreement No FSS/2014/HEI/W/0114/U/0013)

Predicting Growing Stock Volume of Scots Pine Stands Using Sentinel-2 Satellite Imagery and Airborne Image-Derived Point Clouds

Estimation of forest stand parameters using remotely sensed data has considerable significance for sustainable forest management. Wide and free access to the collection of medium-resolution optical multispectral Sentinel-2 satellite images is very important for the practical application of remote sensing technology in forestry. This study assessed the accuracy of Sentinel-2-based growing stock volume predictive models of single canopy layer Scots pine (Pinus sylvestris L.) stands. We also investigated whether the inclusion of Sentinel-2 data improved the accuracy of models based on airborne image-derived point cloud data (IPC). A multiple linear regression (LM) and random forest (RF) methods were tested for generating predictive models. The measurements from 94 circular field plots (400 m2) were used as reference data. In general, the LM method provided more accurate models than the RF method. Models created using only Sentinel-2A images had low prediction accuracy and were characterized by a high root mean square error (RMSE%) of 35.14% and a low coefficient of determination (R2) of 0.24. Fusion of IPC data with Sentinel-2 reflectance values provided the most accurate model: RMSE% = 16.95% and R2 = 0.82. However, comparable accuracy was obtained using the IPC-based model: RMSE% = 17.26% and R2 = 0.81. The results showed that for single canopy layer Scots pine dominated stands the incorporation of Sentinel-2 satellite images into IPC-based growing stock volume predictive models did not significantly improve the model accuracy. From an operational point of view, the additional utilization of Sentinel-2 data is not justified in this context