Exploring the future use of forests: perceptions from non-industrial private forest owners in Finland     

Liina Häyrinen  Osmo Mattila  Markus Närhi  Anne Toppinen 《Scandinavian Journal of Forest Research》2017,32(4):327-337

The transformation of the forest sector toward a bioeconomy calls for finding new sources of competitive advantage for the whole sector to retain its future viability. Non-industrial private forest owners are an important group of actors in the Finnish forest-based sector, as they supply 80% of industrial roundwood and control numerous other tangible and intangible forest-based ecosystem services. Our study analyzes forest owner views on the future use of forests in Finland, their perceptions on the evolving sectorial interlinkages and the position of the forest sector now and in the future bioeconomy. The data were collected in two phases: through telephone interviews of forest owners (n?=?278) and four focus group (FG) discussions (n?=?17), and were analyzed both qualitatively and quantitatively. The interviews showed that forest owners consider the highest potential for strengthening the sector toward bioeconomy to come from collaboration with energy and construction businesses. During the FG phase, we identified new possibilities founded on forest-based recreational services, cooperation with nature-based tourism and in increasing value-added wood products. In total, forest owners as a high-involvement group emphasized future value creation to be based upon forest ecosystem services and in diversifying the utilization of forests beyond the dominant raw material-driven mindset.  相似文献   

Estimates of essential amino acid requirements from dose-response studies with rainbow trout and broiler chicken: effect of mathematical model.     

M Rodehutscord  M Pack 《Archives of Animal Nutrition》1999,52(3):223-244

A total of 37 dose-response experiments with essential amino acids performed with rainbow trout and broiler chicken were re-evaluated with different mathematical approaches: an exponential model, a four-parameter logistic function, the saturation kinetics model and the broken line approach. The different approaches were compared both with regard to the goodness of fit (r2 and sy.x) and with regard to the allowances which were derived regarding the optimal amino acid level in the diet. The experimental design, particularly the chosen range in dietary amino acid concentration was found to be important for the comparison of models. Amongst the non-linear models, the four-parameter logistic function and the saturation kinetics model appeared superior to the exponential approach, when the range in dietary amino acid concentration was very wide and included both a severely deficient basal level and a level that exceeded the needs of the animal by approximately the factor 2. In these cases, allowances derived from individual experiments were considerably different depending on the model. The allowances based on the exponential and the saturation kinetics approach were 27.7 and 20.7 g lysine/kg DM and 8.0 and 6.3 g methionine/kg DM, respectively, for rainbow trout. For other amino acids studied in rainbow trout the difference due to model was less. Consequently, the predicted 'ideal protein' for rainbow trout was considerably different depending on the model used. The maximum deviation found in different experiments with broiler chicken for the exponential vs. the saturation kinetics approach was 13.0 and 9.7 g lysine/kg and 11.4 and 8.2 g sulfur-containing amino acids/kg, respectively. However, the more restricted the range in dietary concentration was, the lesser became the differences between the different non-linear models. No definite recommendation can therefore be extracted regarding the most suitable, generally applicable mathematical model.  相似文献   

The course of phosphorus excretion in growing pigs fed continuously increasing phosphorus concentrations after a phosphorus depletion.     

M Rodehutscord  M Faust  E Pfeffer 《Archives of Animal Nutrition》1999,52(4):323-334

A balance study was performed in order to quantify the effect of continuously increased phosphorus (P) intake on faecal and urinary P excretion. The aim was to quantify the level of intake where regulatory P excretion becomes relevant for comparative digestibility measurements on P, and when the pig adapts its urinary P excretion to increased P intake. Phosphorus intake of growing pigs was continuously increased on a daily basis starting at a marginal level and P excretion via faeces and urine was continuously followed for 92 days. Two semi-synthetic diets were prepared with different proportions of Na2HPO4 resulting in 2.4 (diet 1) and 6.3 (diet 2) g P/kg DM. Concentration of Ca was adapted to achieve a Ca supply approximately 3.1 fold the digestible P supply. Six castrated male crossbred pigs (31 kg BW) were kept individually in metabolism crates after they had undergone a 14 d P depletion period during which they were fed diet 1 solely. Pigs received 1.04kg of diet 1 per day throughout the experiment, and each day the amount of feed and P supplied to pigs from diet 2 was increased by 12 g and 69 mg, respectively. ME supply was approximately 2.4 fold maintenance and average daily BW gain of pigs during the entire experiment was 690 +/- 30 g. While intake increased linearly, faecal excretion of P and Ca increased non-linearly and could be best described by third order polynomial functions. The proportion of ingested P not excreted via faeces followed a quadratic type of curve with a maximum of 81% at 25 days on experiment and P intake of 4.0 g/d. Thereafter, the proportion decreased continuously. The digestibility of P from diet 2, determined by the slope ratio technique, was constant and not affected by P intake up to a P intake of 5 g/d. Renal P excretion did not exceed inevitable losses until day 60 and increased exponentially thereafter when body P reserves were restored. It is concluded, that an adaptation to surplus P supply occurred earlier on the intestinal than on the renal level. While faecal P excretion appeared regulated depending on the actual requirement for P retention, the regulation via urine depended on the P status of the pig. Once the renal P excretion of growing pigs exceeds a level of 25 mg/d, intake of digestible P cannot be regarded sufficiently low to measure P digestibility as a capacity of the feedstuff.  相似文献   

Carbon storage in loess derived surface soils from Central Germany: Influence of mineral phase variables     

Maren Kahle  Markus Kleber  Reinhold Jahn 《植物养料与土壤学杂志》2002,165(2):141-149

The influence of the soil mineral phase on organic matter storage was studied in loess derived surface soils of Central Germany. The seven soils were developed to different genetic stages. The carbon content of the bulk soils ranged from 8.7 to 19.7 g kg^—1. Clay mineralogy was confirmed to be constant, with illite contents > 80 %. Both, specific surface area (SSA, BET‐N₂‐method) and cation exchange capacity (CEC) of bulk soils after carbon removal were better predictors of carbon content than clay content or dithionite‐extractable iron. SSA explained 55 % and CEC 54 % of the variation in carbon content. The carbon loadings of the soils were between 0.57 and 1.06 mg C m^—2, and therefore in the ”︁monolayer equivalent” (ME) level. The increase in SSA after carbon removal (ΔSSA) was significantly and positively related to carbon content (r² = 0.77). Together with CEC of carbon‐free samples, ΔSSA explained 90 % of the variation in carbon content. Clay (< 2 μm) and fine silt fractions (2—6.3 μm) contained 68—82 % of the bulk soil organic carbon. A significantly positive relationship between carbon content in the clay fraction and in the bulk soil was observed (r² = 0.95). The carbon pools of the clay and fine silt fractions were characterized by differences in C/N ratio, δ¹³C ratio, and enrichment factors for carbon and nitrogen. Organic matter in clay fractions seems to be more altered by microbes than organic matter in fine silt fractions. The results imply that organic matter accumulates in the fractions of smallest size and highest surface area, apparently intimately associated with the mineral phase. The amount of cations adhering to the mineral surface and the size of a certain and specific part of the surface area (ΔSSA) are the mineral phase properties which affect the content of the organic carbon in loess derived arable surface soils in Central Germany most. There is no monolayer of organic matter on the soil surfaces even if carbon loadings are in the ME level.  相似文献   

Phytoextraction of heavy metal contaminated soils with Thlaspi goesingense and Amaranthus hybridus: Rhizosphere manipulation using EDTA and ammonium sulfate     

Markus Puschenreiter  Gudrun Stger  Enzo Lombi  Othmar Horak  Walter W. Wenzel 《植物养料与土壤学杂志》2001,164(6):615-621

Selection of appropriate plant species and rhizosphere manipulation to enhance metal uptake are considered key factors in the development of phytoextraction technologies. A pot trial was conducted with two contaminated soils to investigate the effect of EDTA and ammonium sulfate on the accumulation of heavy metals into shoots of the low‐biomass hyperaccumlator Thlaspi goesingense Hálácsy (Brassicaceae) and the high‐biomass non‐hyperaccumulating plant Amaranthus hybridus (Amaranthaceae). Upon application of 1 g EDTA (kg soil)^—1 metal extractability with 1 M NH₄NO₃ increased substantially, whereas the application of (NH₄)₂SO₄ was less effective. The EDTA treatment increased the heavy metal concentrations in both plant species, however, the difference to the control was larger for A. hybridus. EDTA enhanced shoot concentrations in A. hybridus grown on soil Arnoldstein from 32.7 mg kg^—1 to 1140 mg kg^—1 for Pb and from 3.80 mg kg^—1 to 10.3 mg kg^—1 for Cd. Cd concentrations in shoots of T. goesingense were also increased by EDTA application, however, a slight decrease was observed for Pb. T. goesingense accumulated 2840 mg Pb kg^—1 without any treatment. This is the first report of Pb hyperacumulation by T. goesingense. A decrease of shoot Pb concentration was observed in T. goesingense upon treatment with ammonium sulfate. Although metal concentrations in the shoots were rather large and significantly increased upon application of EDTA, plant growth and heavy metal removal were still too small to obtain reasonable extraction rates in soils heavily polluted by metals. It should be also noted that metal lability largely increased in EDTA‐treated soils and this lability persisted for several weeks after the application of the chelating agent, which is likely to be associated with the risk of groundwater contamination.  相似文献