We will organise a forest excursion to Latvia by the end of August. Our host will be the Latvian State Forest Research Institute “Silava” (www.silava.lv). We will fly to Riga early morning on Wednesday 27 August. The first day programme will include, among other sites, an afforestation experiment and its impact on carbon balance and biological diversity, forest fertilisation and management of organic soils. The second day programme will include small-scale logging, climate-smart management of Norway spruce and beech, which is a new species in Latvia brought by the warming climate. The last day will include a visit to the laboratories of Silava, Riga city forest management and human-forest relationships in Latvia. We will return to Finland late in the Friday evening.
The second day will include a seminar with Latvian forest scientists and we will discuss also on cooperation opportunities. The participating Finnish scientists are asked to prepare a short presentation on their work. Working language during the excursion will be English. Check full programme below.
The price of the excursion will be 290 € for the members of the Finnish Society of Forest Science and 360 € for all others. The price includes flights Helsinki – Riga – Helsinki, a charter buss, accommodations and main meals. Non-refundable registration fee of 80 € will be collected soon after registration. The rest of the price will be collected in July.
Register using this form at latest on 13 June 2025:
https://docs.google.com/forms/d/1PQB5OI7ds19QjfE73HH-i3I7-mhnDXR6kso8x9VBqPs
Programme
Wed 27 Aug 2025
6:45 Meeting in Helsinki-Vantaa airport
9:00 Flight departure to Riga, Air Baltic BT302
9:55 Flight arrival to Riga airport
10:30 Departure from airport to Ķeipene
11:20 Lunch stop during the bus drive or in the forest in Ķeipene
13:00 Ķeipene
Afforestation is one of the main tools to fulfil the obligations of climate change mitigation in Latvia. The study site was established in 2012-2014 to address the following knowledge gaps:
- Selection of species – a lot ow work is done on spruce and birch, but we need more on trees like alders (black and grey), cherry or linden. For comparison, hybrid aspen and poplar clones are used;
- Spacing: a lot of comparisons have been done on dense stands (2000 to 25000 trees ha-1), but the site addresses the knowledge gap on sparse plantations (500 – 1500 trees ha-1)
- Species x spacing x fertilization interactions need to be considered in afforestation with emphasis on biodiversity. We will learn about surveys on ground vegetation and advances in other aspects of biodiversity.
14:00 Departure to Mežole
Coffee / snack during the drive or in the forest in Mežole
15:30 Site visits in Mežole
Forest fertilisation with mineral fertilizers and wood ash is one of the potentially most efficient climate change mitigation measure in forestry, highlighted in the National Energy and Climate Plan (2024) of Latvia. In the fertilisation site, we will address e.g., the following questions:
- Technical solutions and costs of application of fertilizers;
- Factors affecting efficiency of fertilizers in pine, spruce and birch stands of different age;
- Effect of fertilizers on soil and water properties and nutrients leaching;
- Recommendations for practical applications of wood ash and mineral fertilizers.
Management of organic soils. Management of forests (or even afforestation) on organic soil is classified currently as “bad for climate change mitigation” e.g., in relation to carbon credit schemes. However, on this site we will ask if
- all “organic soils” are the same,
- we have enough evidence or just assumptions behind management decisions, and
- we can ensure evidence-based decision making.
We will see the effect of gradual management (commercial thinning/selective harvest) in contrast to clearcut or no-management (mature and old-growth stands) on birch and Norway spruce, with consecutive seasons of measurements of soil GHG emissions. Effects of modelled risks on resilience and productivity of assessed forests will be demonstrated for discussion.
18:30 Departure to Jaunkalsnava
20:00 Accommodation and dinner in Jaunkalsnava
Thu 28 Aug 2025
8:00 Breakfast
9:00 Site visits in Jaunkalsnava I
Small-scale logging. Research in Latvia has demonstrated that compact class forest machines offer significant advantages in both pre-commercial and commercial thinning operations. These machines are particularly suited for early thinning in young stands, where their light weight and manoeuvrability help to minimise soil compaction and damage to residual trees. Mechanical damage to less than 1% of remaining trees during thinnings with compact machines has been observed, highlighting their precision and suitability for selective thinning in sensitive forest areas. Economic analyses indicate that compact class machines can reduce operational costs in early thinnings. Additionally, their use contributes to the reduction of greenhouse gas emissions, aligning with sustainable forest management practices. Topics for discussion:
- How can the productivity of compact class harvesters and forwarders be optimized in pre-commercial and early commercial thinnings across varying stand densities and species compositions?
- What are the long-term ecological impacts of using compact class machinery on soil compaction, root damage and overall forest health in sensitive areas with low soil bearing capacity?
- How does the integration of compact class forest machines influence the economic viability of thinnings in private forests, particularly in terms of cost per cubic meter and return on investment?
- What advancements in harvester head technology are necessary to enhance the efficiency and quality of operations conducted by compact class machines, especially when dealing with broadleaved species prevalent in Latvian forests?
- In what ways can the deployment of compact class forest machines contribute to the reduction of greenhouse gas emissions in forest management, and how do these contributions compare to those of medium-sized machinery?
Climate smart management of Norway spruce
Beech in Latvia
12:00 Lunch in the forest
13:00 Site visits in Jaunkalsnava II:
Old-growth forests need to be defined, delineated and strictly protected in following years. However, the opinions on what can be considered as old-growth vary greatly. As starting point of the discussion, assessment of old stands – characteristics, short term (5 year) development, carbon storage and sequestration, biodiversity indicators, based on measurements of >1000 sample plots – will be demonstrated in a study site.
Fire and wind disturbances. Increasing frequency of natural and human-induced disturbances are expected, rising the necessity to prevent catastrophic and/or prolonged consequences. Results on initial development of fire parameters depending on weather conditions will be demosntrated based on measurements in birch stands. Further, factors affecting occurrence of primary wind damages and potential to detect these damages will be demonstrated based on measurements in birch stands.
15:00 Coffee with Silava scientists in Vētraine
15:30 Seminar with Silava scientists
- National energy and climate plan and measures in LULUCF sector
- Separation of anthropogenic emissions from natural background (peatland management, drainage)
- Participating Finnish scientists are also asked to give a short presentation on their research.
18:30 Dinner with Silava scientists
Fri 29 Aug 2025
8:00 Breakfast
9:00 Departure to Salaspils
10:30 Visit to Silava laboratories in Salaspils
12:30 Lunch
13:30 Riga forests and human-forest relationships in Latvia.
General introduction of management goals of urban and peri-urban forests, mathematical approach to set the goals at a stand scale, differences in management depending on set goals, effect on economic performance and management challenges. Issues and approaches on selective harvest and following regeneration in pine forests will be discussed on site.
17:30 Arrival to Riga airport
19:40 Departure of the flight to Helsinki, Air Baltic BT307
20:40 Arrival to Helsinki-Vantaa Airport
