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Kimmo P. Suominen Mikko Liukkonen Mirja Salkinoja-Salonen 《Journal of Soils and Sediments》2001,1(1):2-8
Old (>100 years, situated below 15 cm depth) sediment layers, of two humic forest lakes contained 400 to 600 mg of solvent
soluble organic halogen (EOX) (kg C)-1. This was two to three fold more than in the most recent layers at the depth of 0 to 10 cm. Sediment accumulation of EOX
in humic forest lakes correlated positively with the sediment accumulation of organic matter. Lake water concentration of
adsorbable organic halogen (AOX) correlated positively with water concentration of total organic carbon (TOC) and with the
water colour in the different strata, seasons and lakes. These facts suggest that organic halogen in boreal humic lakes originated
from the drainage area. Paleolimnological study of diatom remains showed that sediment concentration of organic halogen correlated
negatively with the historical pH of the lake water column. This fact supports a view that the presence of organic halogen
was promoted by haloperoxidase type of enzyme, which is most active at low pH (3.5 to 4). The dates of forest management events
(clear cutting, prescribed burning) matched with the observed changes in lake water column historical pH and decrease in sediment
content organic halogen in dated sediment layers. Clear cutting and prescribed burning are known to increase soil pH. This
may decrease the intrinsic formation of organic halogens in soil, thereby decreasing the flow of organic halogens from the
runoff area to the forest lake. Our results support a conclusion that changes in natural organically bound halogen in the
sediment were promoted by acidification, forest fires and forest management in the drainage area. The organic halogen content
in the most polluted layer of the pulp mill recipient sediment was 10 to 100 fold as compared to forest lake sediments. 相似文献
64.
This article proposes a planning approach for private forest holdings that have more than one decision maker, e.g. a heirship
group or a joint ownership between siblings. Through a case study example, we illustrate the phases of the proposed planning
process and describe the communication and planning tools used in this process. The final aim is that in the future the forest
planners’ toolkit would include this kind of approach for rather common situations where it is not easy to reach all the owners
for synchronous face-to-face planning sessions. The process started with initial telephone interviews with the forest owners.
From these interviews appropriate alternative forest plans were developed. Indicators and their values from the forest plans
were inputted into the Mesta internet application. The forest owners were also given guidance on how to use the program. After
this they were given time to independently use the program. Once the forest owners finished the use of the program, the results
were collected and analyzed. Among the alternative forest plans, one was approved by all of the forest owners. The results
of trial use involving a North-Karelian forest holding were encouraging. The main benefits of the approach according to the
participants were learning that there are alternatives between which to choose, and reaching a common base level of understanding
holding’s production possibilities for future decisions. After developing the process and technical tools further, the proposed
model could serve joint ownerships over distance also in practice and in larger scale, and, as a result, foster owners’ engagement
on their own forest. 相似文献
65.
Maija Kymäläinen Mikko Havimo Jarmo Louhelainen 《Wood material science & engineering》2014,9(3):170-178
AbstractPre-treating biomass by torrefaction is assumed to improve the material's storage properties because of reducing hydrophilicity. In order to assess the effect of sorption on storage properties, the adsorption of water vapour and capillary absorption of liquid water in torrefied and charred spruce and birch were studied. In addition, the chemical changes were evaluated through Fourier Transform Infrared (FT-IR) spectroscopy. Adsorption decreased notably as severity of treatment increased, as was expected due to degradation of the wood constituents, namely hemicelluloses and amorphous cellulose. Capillary absorption increased with increasing severity in spruce samples while birch showed less change, but the maximum volume for absorption increased with both species. FT-IR results showed an increase in aromatic structures that have a role in forming crystalline structures, possibly leading to increased porosity. Torrefied and charred material should not be stored outside, as liquid water absorbs readily into the material, turning it into a suitable substrate for fungi. 相似文献
66.
Miika Kajanus Antti Iire Tuomo Eskelinen Mikko Heinonen Eric Hansen 《Scandinavian Journal of Forest Research》2014,29(6):603-614
In response to the ongoing multidimensional change occurring in the external environment, forest sector companies must adapt or create new business models. Our primary objectives are to illustrate the use of an expanded Business Model Canvas for business model design as well as highlight additional evaluation tools that we have developed. We do this via an example from a medium-sized US manufacturer of value-added wood products that desired to design a business model for export market entry. We introduce a method for identifying business models, supported by an evaluation tool and core value calculations. The lessons learned are discussed. 相似文献
67.
Sigrid Agenäs Kjell Holtenius Mikko Griinari Erling Burstedt 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(1):25-33
Turnout to pasture involves considerable changes in the feed intake and metabolism of dairy cows. The aim of this study was to investigate how these changes affect milk production and milk fat composition, in cows selected for high (HFI) or low (LFI) milk fat content producing the same yield of 4% fat-corrected milk. Furthermore, two different concentrates, with high or low inclusion of soya oil, were studied. The experiment was conducted with 44 multiparous mid-lactating cows over a 4 week period. Samples of milk and blood were obtained before turnout to pasture, during transition to pasture and when cows were adapted to pasture. Milk yield decreased with 3.6 kg energy-corrected milk (ECM) on average during the first 5 days after turnout to pasture. This decrease, together with a drop in plasma insulin and increased plasma non-esterified fatty acids (NEFA), indicated nutritional insufficiency at turnout to pasture. Milk fat composition changed towards more long-chain fatty acids (LCFA) and fewer de novo synthesized fatty acids. This was probably caused by an increased supply of LCFA of feed and body origin to the udder. LFI cows showed higher levels of conjugated linoleic acid at pasture than HFI cows. 相似文献
68.
Combining holding-level economic goals with spatial landscape-level goals in the planning of multiple ownership forestry 总被引：5，自引：0，他引：5
In Finland, management of biological diversity at the landscape level is complicated by the relatively small size of the holdings. To alleviate this problem, this study presents a hierarchical planning model that aims at combining spatial landscape-level ecological goals with holding-level owner-specific goals. The influence of ecological objectives extends across holding borders, but their impact is greatest in areas where they are least in conflict with the owners goals. This feature, which results in minimum losses to individual landowners, can be called ecological efficiency. In the case study, the ecological objective was to cluster the breeding and foraging areas of flying squirrel (Pteromys volans). Other sets of objectives were related to individual holdings according to the various preferences of the forest owners. The forest plan produced by the presented planning model was compared with two other forest plans: 1) a combination of independent forest holding level plans, which were assumed to represent the outcome of the current planning tradition, and 2) an area-level plan, where the holding borders and holding-specific objectives were not taken into account. The same objective variables and objective weights were used in all plans. All the plans were produced for six planning areas (ranging from 404.6 to 984.9 ha) and 110 forest holdings (ranging from 0.6 to 449.8 ha) within these areas. The case-study results were promising: with the model presented here, the spatial structure of flying squirrel breeding and foraging areas could be improved with only minor losses in holding-level objectives. The spatial structure of the landscape after the 60-year planning period was very close to the area-level plan. This outcome was made possible by synchronizing the treatment proposals across forest-holding borders. The outcome of the model seems promising also from the practical standpoint: because the variation in the objectives of forest owners is efficiently taken into account in optimization, only rarely do the solutions suggest that the holding-level targets be compromised.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
69.
Effects of landscape structure and forest reserve location on old-growth forest bird species in Northern Finland 总被引：4，自引：0，他引：4
Brotons Lluís Mönkkönen Mikko Huhta Esa Nikula Ari Rajasärkkä Ari 《Landscape Ecology》2003,18(4):377-393
Old-growth forest birds in Fennoscandia have sharply declined in numbers during the last decades apparently due to commercial
forest harvesting and fragmentation of old-growth forests. Conservation measures have led to the establishment of a forest
reserve network to assure the persistence of forest birds at a regional scale. However, little is known about the effects
of landscape structure within and around the reserves on the distribution of old-growth forest birds. We used a hierarchical
approach to address the questions of how landscape structure and composition within forest reserves, landscape composition
of surrounding areas and reserve location affect the abundance of resident, old-growth forest birds in the Northern Finnish
forest reserve network. The positive role of particular landscape features on bird distribution indicates that both the proportion
of old-growth forests and the structure of boreal landscape mosaic has an important role in determining the distribution of
these birds. The landscape composition surrounding the reserves proved to be only a weak predictor in species distribution
models, which argues against the primary role of the surrounding matrix in determining species distribution within forest
reserves. Reserves located near the Russian border showed a higher abundance of old-growth birds than more western ones. Once
east-west gradients in overall landscape composition had been accounted for, however, reserves did not differ significantly
in the number of species present. These results suggest that landscape gradients, rather than ecological processes such as
the presence of source areas located along the border with Russia, are the main determinant of the distribution of old-growth
forest birds in the Finnish reserve network. We propose that to enhance regional persistence of old-growth forest birds, conservation
efforts should be primarily directed towards the protection and enhancement of forest habitat quality and natural heterogeneity
of landscapes within targeted areas.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献