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Role of extractive compounds in emulsion stabilisation capacity of wood hemicelluloses
Full text linkHemicellulose-rich extracts obtained by pressurised hot water extraction of wood residues show promise as emulsion stabilisers. However, pressurised hot water extracts (PHWEs) from wood also contain lower molecular weight extractive components that may influence emulsion performance. This study investigated the effect of extractives on emulsion stability using PHWEs obtained from spruce and birch sawdust with or without solvent pre-extraction. The results indicated that extractives negatively affect the physical stability of emulsions in both spruce and birch and influence oxidative stability in spruce after prolonged storage. However, the roles of different extractives in emulsion performance require further investigation.202
Struggling towards co-existence of the Baltic Sea coastal fisheries and the grey seal
Full text linkCommercial small-scale fisheries along the Baltic Sea coasts have declined over the years although these fisheries are viewed as important for coastal development and food security at the local, national, and EU levels. The viability and future of small-scale fisheries are severely challenged by problems caused by grey seals. The conflict, occurring between Baltic Sea coastal fisheries and conservation of the grey seals, has been severe since the mid-1990s and continues despite attempts to find a more balanced situation. Resting on reviews of multiple material, this paper explores the state-of-the-art opportunities for mitigating the seal-fisheries conflict and asks how these are related to social struggles and social justice. Our paper concludes that co-existence of coastal fisheries and the grey seal is possible but necessitates political will and co-designed seal management plans that help implement context-specific measures. Seal deterrents, for instance, give hope as a supplementary conflict mitigation measure – along with seal-proof fishing gear – but provide only partial relief. From the fisheries sector’s position, influencing the size of the seal population is a logical solution. The lifting of the EU trade ban of seal products as a regional derogation would allow sustainable management of seal populations so that they be used as renewable natural resource. Monitoring changes in the seal population is crucial for maintaining a balanced population. Reaching co-existence is timely, because – unlike the seal – the diverse Baltic coastal fishing culture is increasingly endangered.202
Wood Properties and Quality
Full text linkTrees in continuous cover forestry (CCF) typically form very narrow rings at young ages in suppressed positions but can grow very quickly at older ages in dominant positions, maintaining long-lived crowns.
CCF trees have slightly higher mean wood density in stems than rotation forestry (RF) trees.
CCF trees have better fiber properties for pulp than RF trees.
CCF trees have a relatively short stem section of small dead knots in sawn timber.
CCF trees have a relatively long section of large green knots in sawn timber.
Sawn goods produced from spruce logs yielded with the selection system do not differ markedly from those from RF.
The application of a shelterwood system with overstorey retention for Scots pine facilitates the production of very high-grade timber
Carbon dioxide and methane gas exchange following sphagnum moss harvesting in boreal peatland
Full text linkUnderstanding the impacts of Sphagnum moss harvesting on peatland carbon (C) balance is crucial due to its potential rise as an anthropogenic land use. We studied eight nutrient-poor peatlands in Finland, harvested between 2015 and 2021, focusing on net ecosystem exchange of CO2 (NEE) and methane (CH4) emissions. The greenhouse gas fluxes were measured to evaluate the sustainability of harvesting practices. Results showed significant variability in Sphagnum regeneration, with wet strip-harvested sites achieving 2–28% re-establishment in 2–8 years, while drier clear-harvested sites saw minimal spontaneous regeneration in 1–6 years. In addition to vegetation succession, GHG emissions were moisture dependent. In wet sites CH4 emissions increased along with time since harvesting and Eriophorum vaginatum (L.) cover, while dry sites exhibited overall lower CH4 fluxes. Younger (1–2 years post-harvest), dry sites were significant CO2 sources due to low photosynthetic activity. Older dry site with sparse ericoid shrub vegetation acted as CO2 sink. Wet sites initially had lower CO2 sink capacity, but this increased as E. vaginatum spread, and reached a plateau when Sphagnum mosses emerged, highlighting the importance of suitable water table levels for efficient CO2 sequestration
Inarijärven taimenen tila : muutokset lisääntymismenestyksessä ja jokisaaliissa 2000-luvulla
Full text linkInarijärvi on Suomen merkittävin järvitaimen (taimen, Salmo trutta) -vesistö, ja siihen laskevat joet ylläpitävät maan viimeisiä elinvoimaisia järveen vaeltavia taimenkantoja. Osana Inarijärven ja sen sivuvesistöjen kalataloustarkkailua on tehty sähkökoekalastuksia Inarijärveen laskevissa keskeisimmissä taimenjoissa vuodesta 2004. Lisäksi jokisaaliista otetaan vuosittain kalanäytteitä, joiden perusteella voidaan arvioida kudulle nousevan kannan tilassa tapahtuvia muutoksia.
Jokipoikasseurantojen perusteella voidaan todeta, että Juutuanjoen poikastiheydet ovat hyviä verrattuna muihin pohjoisiin järvitaimenen lisääntymisjokiin, keskimäärin noin 15 poikasta aarilla. Tämä tekee Juutuanjoesta Inarijärven vesistön tuottoisimman taimenen lisääntymisjoen. Ivalojoen pääuomassa poikastiheydet ovat pienempiä, mutta sivujokien tiheydet ovat hyviä, noin 14,6 poikasta aarilla. Sotajoen poikastiheydet ovat heikoimmat kullankaivuun vuoksi. Siuttajoen poikastiheydet ovat keskitasoa.
Ilmastonmuutos voi vaikuttaa vesien lämpenemiseen ja kasvukauden pituuteen, mikä näkyy etenkin Juutuanjoessa nopeutuneena taimenen poikasten kasvuna. Istutettujen taimenten osuus Juutuanjoen saaliissa on kasvanut etenkin joen alaosalla. Koska istutetut taimenet sukukypsyvät nuorempina, ja yleensä pienempinä, tämä näkyy viimeisen kymmenen vuoden aikana Juutuanjoesta pyydettyjen taimenten keskipituuden pienenemisenä. Kalastuksen valikoivuuteen tulisikin kiinnittää huomiota, jotta pyyntipaine kohdistuisi enemmän istutettua alkuperää oleviin kuin villeihin taimeniin. Saalistiedustelun mukaan jokien taimensaalissa ei ole tapahtunut suuria muutoksia tarkastelujakson aikana.
Kahdenkymmenen vuoden sähkökoekalastusseuranta Inarijärven taimenjoissa on paljastanut poikastiheyksien olevan vakaampia ja runsaampia kuin aiemmin on arvioitu, mutta jokien välillä on havaittavissa suuriakin eroja, ja toisaalta vuosittaiset vaihtelut voivat olla suuria. Eri ikäiset poikaset käyttävät erilaisia elinympäristöjä, mikä tulee huomioida seurantojen toteutuksessa. Poikasten koon ja kasvun muutoksia paitsi eri jokien välillä myös laitosviljelyssä tulisi tutkia tarkemmin, jotta mahdollisiin seurauksiin pystyttäisiin varautumaan
Slow recovery of microclimate temperature buffering capacity after clear-cuts in boreal forests
Full text linkThe majority of Fennoscandian boreal forests are managed. Forest management inherently changes the physical structure of forests, thus altering ecosystem functions and the conditions for living organisms within these environments. However, the impacts of management on the microclimate buffering of boreal forests have not been comprehensively studied, despite that microclimate is one of the key determinants of biodiversity. Here, we studied the effect of forest structure and management on the temperature buffering capacity of boreal forests using terrestrial laser scanning and microclimate measurements. We measured the temperature variability on forest plots representing two management types: even-aged rotation forestry and uneven-aged forestry. To quantify buffering, we calculated the slope coefficient of the linear regression between microclimate and clear-cut temperatures. We found that the total amount of plant material alone was not an adequate predictor of the buffering. Instead, increasing canopy layers and the density of the understory led to more buffered temperature variability compared to clear-cuts and forests with fewer layers. The buffering was high in both mature even-aged and uneven-aged sites, but the effect in even-aged forests depended on stand age, suggesting that a strong buffering capacity could be reached only after approximately 30 years after clear-cut. In uneven-aged stands, the buffering capacity varied with recurring partial selection cuttings, but never lead to a full coupling with open-air temperatures like in even-aged stands after clear-cuts. We conclude that despite the buffering being on average stronger in mature even-aged stands than in uneven-aged stands, it can take decades for a clear-cut stand to reach the same buffering capacity as an uneven-aged forest with continuous tree cover, and it will eventually disappear after a new clear-cut harvest. From biodiversity perspective, uneven-aged management can create more temporally stable microclimatic conditions and can thus aid in maintaining microrefugia and mitigate climate warming impacts