Imprints of management history on hemiboreal forest ecosystems in the Baltic States

In the Baltic States region, anthropogenic disturbances at different temporal and spatial scales mostly determine dynamics and development phases of forest ecosystems. We reviewed the state and condition of hemiboreal forests of the Baltic States region and analyzed species composition of recently established and permanent forest (PF). Agricultural deforestation and spontaneous or artificial conversion back to forest is a scenario leading to ecosystems designated as recent forest (RF, age up to two hundred years). Permanent forest (PF) was defined as areas with no records of agricultural activity during the last 200 yr, including mostly forests managed by traditional even-aged (clear-cut) silviculture and salvage after natural disturbances. We hypothesized that RF would have distinctive composition, with higher dominance by hardwoods (e.g., aspen and birch), compared to PF. Ordination revealed divergence in the RF stands; about half had the hypothesized composition distinct from PF, with a tight cluster of stands in the part of the ordination space with high hardwood dominance, while the remaining RF stands were scattered throughout the ordination space occupied by PF with highly variable species composition. Planting of conifers, variability in site quality, and variability in spatial proximity to PF with relatively natural ecosystem legacies likely explained the variable compositions of this latter group of RF. We positioned the observations of RF in a classic quantification of site type conditions (based on Estonian forest vegetation survey previously carried out by LA mu hmus), which indicated that RF was more likely to occur on areas of higher soil fertility (in ordination space). Climatic and anthropogenic changes to RF create complex dynamic trends that are difficult to project into the future. Further research in tracing land use changes (using pollen analysis and documented evidence) should be utilized to refine the conceptual framework of ecosystem legacy and memory. Occurrence and frequency of deforestation and its characteristics as a novel disturbance regime are of particular interest.Peer reviewe

Harmonised statistics and maps of forest biomass and increment in Europe.

peer reviewedForest biomass is an essential resource in relation to the green transition and its assessment is key for the sustainable management of forest resources. Here, we present a forest biomass dataset for Europe based on the best available inventory and satellite data, with a higher level of harmonisation and spatial resolution than other existing data. This database provides statistics and maps of the forest area, biomass stock and their share available for wood supply in the year 2020, and statistics on gross and net volume increment in 2010-2020, for 38 European countries. The statistics of most countries are available at a sub-national scale and are derived from National Forest Inventory data, harmonised using common reference definitions and estimation methodology, and updated to a common year using a modelling approach. For those counties without harmonised statistics, data were derived from the State of Europe's Forest 2020 Report at the national scale. The maps are coherent with the statistics and depict the spatial distribution of the forest variables at 100 m resolution

Piejuras mezu atjaunosanas un apsaimniekosanas modelu izstrade

Available from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLEMinistry of Agriculture of the Republic of Latvia, Riga (Latvia)LVLatvi

Piejuras mezu atjaunosanas un apsaimniekosanas modelu izstrade

Available from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLEMinistry of Agriculture of the Republic of Latvia, Riga (Latvia)LVLatvi

Differential Analysis for Next Breeding Cycle for Norway Spruce in Latvia

Breeding in the most of the Baltic Sea region countries has been used as an important tool to improve target traits of forest trees for more than 60 years. Its basis is an extensive plus-tree selection: in Latvia alone 1700 Norway spruces were identified and their open pollinated progeny tests established. Despite this effort and proven superiority of the selected material, during the last decades share of natural regeneration is increasing at the expense of planting of selected material. Therefore, before entering the next breeding cycle, objective of our study was to optimise the Norway spruce breeding strategy (testing method, duration, family size) under Latvian conditions, and carry out its financial analysis. Alternative breeding strategies were optimised with the aid of computer simulation and differential analysis comparing planting of selected (improved) material and natural regeneration was applied. Neither duration, nor costs of different alternative strategies were the same, therefore equivalent annual annuity was used as a criterion for comparison. The simulations showed that the total genetic gain per cycle differs between the breeding strategies: the GEN strategy yielded 9 % more, but the FEN strategy 30 % (testing time 20 years) or 21 % (testing time 25 years) less than the VEG strategy. For the base scenario in Latvia (the interest rate r = 3 %; the deployment time of the selected material 24 years; the annual planting area is 5500 ha; the genetic gain varies from 25 to 45 %) the equivalent annual annuity from spruce breeding was positive and in range from 2.0 to 12.9 EUR ha-1y-1. Even if a 5 % interest rate for investments in tree breeding and seed orchard management were applied, it was more profitable for the forest owner to regenerate areas with genetically improved material than to rely on natural regenerationVytauto Didžiojo universitetasŽemės ūkio akademij

Rekomendaciju izstrade ilgtspejigas meza apsaimniekosanas kriteriju un indikatoru sistemai Latvija saskana ar 2. un 3. Ministru konferencu par meza aizsardzibu Eiropa pienemtajiem lemumiem

Available from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLEMinistry of Agriculture of the Republic of Latvia, Riga (Latvia)LVLatvi

Stem Damage Modifies the Impact of Wind on Norway Spruces

Bark stripping caused by cervids can have a long-lasting negative effect on tree vitality. Such trees of low vitality might be more susceptible to other disturbances. The amplifying effects of disturbance interactions can cause significantly more damage to forest ecosystems than the individual effects of each disturbance. Therefore, this study aimed to assess the impact of bark stripping (stem damage) on the probability of wind damage and snapping height for Norway spruces (Picea Abies (L.) H. Karst.). In this study, we used the Latvian National Forest Inventory data from the period 2004–2018. In the analysis, we used data based on 32,856 trees. To analyse the data, we implemented a Bayesian binary logistic generalised linear mixed-effects model and the linear mixed-effects model. Our results showed that stem damage significantly increased the probability of wind damage and affected the snapping height of Norway spruces. Similarly, root damage, the slenderness ratio, the stand age, the stand density, the soil type, and the dominant tree species had a significant influence on the probability of wind damage. In both periods, trees with stem damage had significantly (p < 0.05) higher probability (odd ratio 1.68) to be wind damaged than trees without stem damage. The stem damaged Norway spruce trees snapped in the first 25% of the tree height, while trees without stem damage snapped around half (50%) of the tree height. Our results show that stem damage significantly alters the effect of wind damage on Norway spruces, suggesting that such damage must be incorporated into wind-risk assessment models

A Financial Assessment of Windstorm Risks for Scots Pine Stands in Hemiboreal Forests

Windstorms are a significant disturbance in northern European Scots pine forests. Mechanistic models for assessment of their impact have been developed. The aim of our study was to assess the impact of windstorms on the financial value of Scots pine (Pinus sylvestris L.) stands. Wind damage probability in stands with certain dimensions (linked to age and site index) and the reduced value retrieved from salvage logging instead of planned harvest in undamaged stands were used for calculation. Equivalent annual annuity with interest rates of 3%, 4%, and 5%, three different commercial thinning regimes, and different planting densities were used to assess the mean influence. Wind damage risk had a notable and significant negative effect on the financial value of Scots pine forest stands. Equivalent annual annuity decreased sharply with stand age, especially in the most productive sites (SI 36). The negative financial impact could be reduced by selection of a lower initial planting density (1000–2000 trees ha−1 instead of 3000) and by reducing the rotation period, for example, by using target diameter as the criteria for the time of final harvest

Growing stock monitoring by European National Forest Inventories

Wood resources have been essential for human welfare throughout history. Also nowadays, the volume of growing stock (GS) is considered one of the most important forest attributes monitored by National Forest Inventories (NFIs) to inform policy decisions and forest management planning. The origins of forest inventories closely relate to times of early wood shortage in Europe causing the need to explore and plan the utilisation of GS in the catchment areas of mines, saltworks and settlements. Over time, forest surveys became more detailed and their scope turned to larger areas, although they were still conceived as stand-wise inventories. In the 1920s, the first sample-based NFIs were introduced in the northern European countries. Since the earliest beginnings, GS monitoring approaches have considerably evolved. Current NFI methods differ due to country-specific conditions, inventory traditions, and information needs. Consequently, GS estimates were lacking international comparability and were therefore subject to recent harmonisation efforts to meet the increasing demand for consistent forest resource information at European level. As primary large-area monitoring programmes in most European countries, NFIs assess a multitude of variables, describing various aspects of sustainable forest management, including for example wood supply, carbon sequestration, and biodiversity. Many of these contemporary subject matters involve considerations about GS and its changes, at different geographic levels and time frames from past to future developments according to scenario simulations. Due to its historical, continued and currently increasing importance, we provide an up-to-date review focussing on large-area GS monitoring where we i) describe the origins and historical development of European NFIs, ii) address the terminology and present GS definitions of NFIs, iii) summarise the current methods of 23 European NFIs including sampling methods, tree measurements, volume models, estimators, uncertainty components, and the use of air- and space-borne data sources, iv) present the recent progress in NFI harmonisation in Europe, and v) provide an outlook under changing climate and forest-based bioeconomy objectives