The application of remote sensing techniques in forestry
The world’s terrestrial ecosystems store between 21 and 26 billion tonnes of carbon each year, with forests accounting for more than half of this total. Forest ecosystems are responsible for over 90% of the carbon fluxes between land and the atmosphere. By sequestering significant amounts of atmospheric carbon dioxide (CO2), forests play a crucial role in the global carbon cycle and serve as a valuable tool for mitigating the impacts of climate change. However, rapid climate change is threatening the stability and resilience of these ecosystems, thereby reducing their long-term capacity to sequester CO2.
Forests in the Czech Republic mainly serve an economic purpose, with the production of raw wood materials, especially spruce, playing a crucial role in the local economy. Beyond their economic value, forests also provide various important non-economic functions and services that benefit society and the environment. These include water management, soil protection, recreation, climate regulation, and landscape preservation. However, these valuable services are often not adequately recognized or valued in economic terms.
The primary interest of the state, forest owners, and forest users should be the sustainable management of forests. This includes supporting their prosperity and enhancing their ability to provide a variety of productive and non-productive functions through appropriate interventions. This objective is also strongly highlighted in the new EU Forest Strategy for 2030 (EU, 2021).
Forest functions can be evaluated through several methods, and remote sensing (DPZ) techniques present intriguing opportunities. A team of scientists from various institutions, working on the TAČR research project Kappa TO01000345, titled “Performance of production and regulatory functions of forests in the past, present, and future – what can be expected from forest ecosystems affected by climate change?” (Plnění produkční a regulačních funkcí lesa v minulosti, současnosti a budoucnosti – co lze očekávat od lesních ekosystémů ovlivněných klimatickou změnou?) developed a certified methodology Ohodnocení ekosystémových funkcí lesních porostů pomocí metod dálkového průzkumu Země /DPZ/ (Assessment of forest ecosystem functions using remote sensing /RPS-DPZ/).
In the methodology, scientists outline procedures for monitoring and quantifying specific ecosystem functions of forest stands using methods derived from DPZ data (satellite and aerial). These methods can be employed to track long-term trends as well as the current state of both the production and regulatory functions of forests in the Czech Republic. The regulatory function refers to the capacity of forest ecosystems to influence hydrological and climatic conditions by affecting the energy and water balance in the landscape and the atmosphere.
The assessment procedure that analyses long-term trends in productivity and evapotranspiration using satellite data has not yet been implemented in the Czech Republic.
Remote Sensing (DPZ) methods provide significant time and financial savings compared to traditional ground surveys. Forest workers can utilize DPZ outputs, such as maps of productivity, evapotranspiration, and forest health, as valuable data for planning field surveys, managing forests, and protecting or logging areas.
Additionally, these data will help in effectively identifying problematic locations and recognizing key areas where the forest is either thriving or struggling. One notable advantage of the DPZ approach is the ability to compare productivity maps, which can highlight deviations from long-term norms, potentially indicating urgent forest-related issues.
The methodology for quantifying forest ecosystem functions using DPZ methods offers a ground-breaking approach to assessing the production and regulatory functions of forest ecosystems in the Czech Republic. By integrating with climate models, this methodology provides a valuable tool for strategic planning, facilitating the adaptation of forestry practices to climate change, and enhancing the effective use of subsidies. Its implementation has the potential to significantly impact the economics of forestry and influence policy-making in support of sustainable management practices.
In current time, climate change significantly impacts the functioning of forests, making information on changes in the fulfilment of individual forest functions crucial. The methods presented—such as long-term time series data and monitoring of forest functions at detailed temporal and spatial scales—offer an innovative source of information.
This methodology allows for the analysis of the impacts of different management models on the fulfilment of ecosystem functions. For instance, the data can be utilized to compare approaches such as intensive logging, close-to-nature management, and no intervention, evaluating which model best balances economic efficiency with ecological stability.
This information is vital for strategic planning in forestry. Additionally, predictions regarding forest production capacities under future climate conditions enable adjustments to logging and afforestation practices, ensuring long-term economic benefits.
For example, data obtained through this methodology can help direct subsidies toward forest restoration in areas affected by bark beetles, focusing on species-diverse plantings that enhance ecological stability and the cooling function of the forest. Similarly, funding could be allocated for afforestation in drought-affected regions to boost the forest’s water retention capacity. Another approach could be to introduce incentives for forest owners who achieve above-average performance in ecosystem function over the long term, thereby encouraging more sustainable management practices.
The integration of methodological data and climate models enables the prediction of risks related to the loss of production functions and facilitates the planning of preventive measures. This proactive approach helps to minimize potential economic losses in the future.
There is significant potential in utilizing modern ground-based monitoring techniques that employ continuous measurements and advanced real-time data transmission technologies. This combination allows for more accurate monitoring of carbon flows within forest ecosystems, both spatially and temporally, emphasizing the crucial role that forests play in storing and sequestering carbon.
Furthermore, this integration of methods holds substantial economic potential by establishing a precise system for quantifying carbon offsets. These offsets are based on the ability of forests to sequester carbon dioxide, which can help counterbalance emissions produced elsewhere. This strategy not only supports the fight against climate change but also creates economic opportunities in the realm of carbon management. As a result, forestry has a significant opportunity to assess its contributions through substantial financial returns associated with carbon offsets.
The methodology introduces a significant innovation in forest management in the Czech Republic. By enabling targeted financial support distribution, assessing management efficiency, and planning for climate change adaptation, it serves as a vital tool for ensuring the long-term stability of forest ecosystems and their economic contributions. This comprehensive approach integrates sustainability, ecological functions, and economic efficiency, making it a fundamental component of future forest management strategies.
The methodology Ohodnocení ekosystémových funkcí lesních porostů pomocí metod dálkového průzkumu Země (Assessment of forest ecosystem functions using remote sensing) can be downloaded here.
Authors: Ing. Lucie Homolová, Ph.D. a kol., Ústav výzkumu globální změny AV ČR, v. v. i. (Global Change Research Institute of the Czech Academy of Sciences), Brno
Prepared from the original by Jan Řezáč, VÚLHM, v. v. i. Email: rezac@vulhm.cz
Illustrative photo: Forests around the Vltava River in Central Bohemia, author Jan Řezáč