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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2024

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Abstract

Uneven-aged forests set certain challenges for cut-to-length harvesting work. It is a challenge to cost-effectively remove larger trees while leaving a healthy understory for regrowth. The study’s aim was to evaluate productivity and costs of harvesting two-storied silver birch (Betula pendula Roth) and Norway spruce (Picea abies (L.) H. Karst.) stands by creating time consumption models for cutting, and using existing models for forwarding. Damage to the remaining understory spruce was also examined. Four different harvesting methods were used: 1) all dominant birches were cut; 2) half of them thinned and understory was preserved; compared to 3) normal thinning of birch stand without understory; and 4) clear cutting of two-storied stand. Results showed the time needed for birch cutting as 26–30% lower when the understory was not preserved. Pulpwood harvesting of small sized spruces that prevent birch cutting was expensive, especially because of forwarding of small amounts with low timber density on the strip roads. Generally, when taking the cutting and forwarding into account, the unit cost at clear cuttings was lowest, due to lesser limitations on work. It was noted that with increasing removal from 100 to 300 m3 ha–1, the relative share of initial undamaged spruces after the harvest decreased from 65 to 50% when the aim was to preserve them. During summertime harvesting, the amount of stem damage was bigger than during winter. In conclusion, two-storied stands are possible to transit to spruce stands by accepting some losses in harvesting productivity and damages on remaining trees.

Abstract

In the frame of EUFRIN apple rootstock trials, seven apple rootstocks are being tested for their resistance to ARD (apple replant disease) in several European countries. Current paper focus on the rootstock and soil type (ARD vs. fresh soil) effect on the accumulation of phenolic compounds in apple fruit. This research was performed at the Lithuanian trial site. Accumulation of phenolics compounds in fruit tissues was enhanced at replant soil. On the average of all rootstocks, total phenol content in fruit flesh increased by 25%, and in fruit peel by 31%. Hyperoside and rutin in fruit flesh and hyperoside, reynoutrin, phloridzin and procyanidin C1 were the most variable among detected phenolic compounds and their content in fruits from ARD soil was by 50 – 77 % higher than in fruits from the fresh soil. Content of (-) epicatechin in fruit flesh and (+) catechin and procyanidin B1 in fruit peel was similar in both ARD and fresh soil. Rootstock had a significant effect on the accumulation of phenolic compounds, but this effect was modified by soil conditions. Soil type had no effect on total phenol accumulation in fruits (flesh and peel) grown on Pajam 2 rootstock. Also, a stable phenol content in fruit flesh was on G.11 and M200 rootstocks, and in fruit peel on G.41. The highest increase of total phenol content at replant conditions was recorded on B.10 (by 66% in flesh and 60% in peel) and on G.935 (by 68% in flesh and 47% in peel) rootstocks.