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41.
Mikko Kurttila Eero Muinonen Pekka Leskinen Harri Kilpeläinen Jouni Pykäläinen 《European Journal of Forest Research》2009,128(1):37-50
A proper forest planning process includes the assessment of the decision-makers’ preferences concerning the future forest
use. For some owners, it may be a difficult task to express their preferences exactly and in the form that is required for
planning calculations. This study presents a new kind of approach for analyzing the effects of preferential uncertainty. The
approach consists of examination of the differences in the actual decision variables in forest planning, i.e. selected treatments
for stands between holding-level forest plans. In example calculations, the preferential uncertainty was examined from three
different viewpoints: the uncertainty in the weights of the objective variables; the uncertainty in the partial utility function;
and the combination of these two uncertainty sources. One thousand preference realizations were generated for each of these
uncertainty sources. More than one treatment schedules are proposed for stands that are affected by preferential uncertainty.
These stands were detected from among the resulting set of 1,000 forest plans. With this done, two potential decision-making
strategies, an adaptive behavior strategy and a threshold proportion strategy, were applied as guides in decision-making for
stands, which have more than one treatment alternative selected in the produced optimal forest plans. The adaptive behavior
technique required that the forest owner select one treatment alternative for at least one stand that has more than one proposed
treatment alternative. The treatment alternatives having frequencies exceeding the given threshold frequency were all accepted
simultaneously in the threshold strategy. The main benefit of the approach is to present the effects of uncertainties in a
way that can be easily understood by the actual decision-makers. It is a promising tool for practical decision-making situations
because at least Finnish non-industrial private forest owners quite often focus on making stand-level forest management decisions.
It is also suitable for examinations of other uncertainty sources such as timber prices or inventory data. 相似文献
42.
Voluntary biodiversity protection tools have been adopted for practical use in many countries where non-industrial private
forest ownership includes invaluable biodiversity resources. This has created a new kind of decision problem for individual
forest owners: they should be able to define their conditions for entering into a biodiversity protection contract including
sometimes a predetermined subsidy. This study presents a holding-level method for examining this decision problem. The method
is based on utilization of interactive optimization where the possible subsidy has been included in the protection (no treatment)
alternative of the examined stand. Generally, interactive optimization means that the landowner pinpoints the best plan by
interactively studying and learning the production possibilities of his/her forest holding. Following changes made to the
objective function by the forest owner, new solutions are presented for forest owners’ evaluation. If the “No treatments”
option is selected in optimization for these areas, the forest owner would benefit more—in the current location of the production
frontier and with the current subsidy—from entering into the protection contract than from cutting the specific forest area.
In the case study, we demonstrate that the values of the holding-level goals, production possibilities of the planning area
and the levels of the subsidy have a significant effect on the optimal decisions relating to biodiversity protection on the
stand level. 相似文献
43.
Pirjo Yli-Hemminki Timo Sara-Aho Kirsten S. Jørgensen Jouni Lehtoranta 《Journal of Soils and Sediments》2016,16(8):2138-2152
Purpose
Deposits of iron–manganese (Fe, Mn) concretions forming a large storage of phosphorus (P) and arsenic (As) are frequently under pressure of oscillating oxygen conditions in the eutrophic Gulf of Finland, the Baltic Sea. Yet, there is a poor understanding how anaerobic microbial processes regulate the cycling of elements in the concretions. The objective of this study was to highlight how the microbial processes control the release of elements from the concretions to brackish water during anoxia.Materials and methods
Spherical concretions were collected from the oxic bottoms of the Gulf of Finland in the summer. Concretions and autoclaved controls were incubated in anoxic artificial brackish seawater with and without labile carbon, plus supplied with ammonium at 5, 10, and 20 °C for 15 weeks. Concentrations of Fe, Mn, P, and As were measured from the intact concretions and the ambient solutions during the experiment. Also, the consumption of the added ammonium and organic carbon and the formation of dissolved inorganic carbon were measured.Results and discussion
At near-bottom temperature 5 °C, the concretions released at highest 0.12, 0.42, 0.02, and 0.0002 μmol g?1 day?1 of Fe, Mn, P, and As, respectively. The rates were significant only in the microcosms with added labile carbon, and only minor proportions (0.1–0.4 %) of their total contents were released during the incubations. The concretions removed completely the supplied ammonium only without carbon addition. We find that concretion deposit may form a local hot spot for the microbial reduction of Fe and Mn and release significant amounts of P and As, and participate in N cycling besides the bottom sediments of the Gulf of Finland during prolonged anoxia. However, the concretions may maintain their binding capacity for P and As longer than the fine-grained organic-rich sediment during anoxia.Conclusions
During anoxia concretion deposits may form a temporal source of bioavailable P having ecological significance in the Gulf of Finland when concretions have access to labile organic carbon. Concretions from the Baltic Sea, the oceans, lakes, and soils contain high concentrations of Mn and Fe, but their proportions vary considerably. Anaerobic microbial processes may thus affect the stability of concretions from the different environments, but the outcome may depend on the ambient geochemical conditions.44.
45.
Mikko Kurttila Jouni Pykäläinen Pekka Leskinen 《European Journal of Forest Research》2006,125(1):67-78
New, cost efficient and voluntary biodiversity protection tools may require bidding price definition on part of the seller.
Both the seller and the buyer can withdraw from negotiations if they find that the conditions of the protection contract are
unacceptable. However, it can be very difficult for non-industrial, private landowners to define the bidding price demand
for their biodiversity objects. The terms of the protection contract, the production possibilities of the forest holding,
the forest owner’s multiple forest management goals and their substitutability, and the possible monetary subsidy paid for
biodiversity protection should all be simultaneously taken into account when estimating the owner’s price demand for protecting
the biodiversity object. This study strives to provide relief in resolving this problem by presenting an approach in which
the landowner’s utility–loss compensative subsidy can be defined based on the owner’s forest-holding level utility function
and the production possibilities of the holding. The properties of the approach are illustrated by four planning cases in
which the length of the protection period (permanent or 20-year temporary protection) and the holding-level goals were varied.
The utility functions of the cases were derived by selecting numeric goal variables for the goals, and by defining weights
and sub-utility functions for these variables. Varying subsidies for protecting an old-growth spruce stand were included into
the simulation of “No treatment” schedules for the examined stand, and the holding-level total utility was maximized for every
price level. The utility–loss compensative subsidy was found when the holding-level total utility equaled the total utility
achieved in the plan where the stand was regenerated. This subsidy, however, is not necessarily the exact price that the owner
should ask from the buyer; all prices above the defined subsidy level will increase owner’s utility if the buyer accepts them.
It was concluded that the presented approach provided consistent results in the four cases and that it thus offers valuable
decision support for current biodiversity-protection programs. 相似文献
46.
The purpose of this study was to examine different non-parametric imputation methods to reduce regional biases in growth estimates. Growth estimates were obtained using non-parametric k-nearest neighbour imputation (k-NN) to predict future 5-year diameter increment over bark at breast height for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies). The Mahalanobis distance function was chosen as the most suitable measure of similarity, and then it was modified using weights provided by linear regression analysis. The use of weights from linear regression facilitated the examination of the correlation structure of the variables and allowed for transformations of the independent variables. Localization of the non-parametric estimates was obtained through a variety of methods, in particular, by using spatial coordinates as independent variables, by restricting the selection of neighbours to a circular area around the target tree, and by restriction the selection of neighbours to a local database. The localized estimates using spatial measures were then compared with non-spatial imputation and also with estimates from a parametric growth model. Results were then compared by vegetation zones in Finland. The differences between the non-spatial k-NN estimates and the localized spatial estimates were negligible when summarized to the stand level, and localization did not reduce the regional biases relative to the non-spatial k-NN estimates. Regional biases in northern Finland and in south-western Finland were reduced substantially using the non-parametric estimates rather than the parametric growth models, however, and the mean biases in all of the regions were quite similar, while the mean biases of the growth estimates obtained with the parametric model varied notably between the regions. 相似文献
47.
Comparison of treewise and standwise forest simulators by means of quantile regression 总被引：1，自引：0，他引：1
Antti Mäkinen Annika KangasJouni Kalliovirta Jussi RasinmäkiEsko Välimäki 《Forest Ecology and Management》2008
Predicting forest development under varying treatment schedules forms the basis of forest management planning. The actual growth predictions are made with a forest simulator which includes growth equations and additional models for predicting a number of varying tree, forest and site properties. Forest growth simulators typically include either tree-level or stand-level growth models, but these two approaches have not been thoroughly compared. We set out here to compare these two approaches with the SIMO simulator framework in a small data set from southern Finland based on 60 sample plots in 30 stands, the development of which was known for 20 years. The stands chosen were very dense, so that the simulators could be tested under extreme conditions. The results show that the stand-level model is more accurate in almost all cases and its computational burden is much lower. It could therefore be advisable to use tree-level models for short-term predictions, which would ensure detailed information on forest structure for planning the near-future operations. Stand-level models would be more advisable in longer term predictions, especially when accurate volume estimates are considered more important than the forest structure. The errors observed in these simulators were analysed further by quantile regression, which allows empirical estimates of confidence intervals to be obtained for the simulator. 相似文献
48.
Riina Antikainen Reija Haapanen Riitta Lemola Jouni I. Nousiainen Seppo Rekolainen 《Water, air, and soil pollution》2008,189(1-4):163-177
An assessment of the environmental quality of sediments at several locations of the Ría de Pontevedra (NW of Spain) was performed by integrating toxicity data obtained from multiespecies bioassays, chemical data from analysis of mussels and sediment, and physical–chemical parameters of the sampled sites. Subsequently, a toxicity identification evaluation (TIE) method intended for characterization and identification of the toxic agents was applied to the most polluted location by using the Paracentrotus lividus sea urchin bioassay. Both metals and organic compounds seem to be the causative agents of toxicity in elutriates of the studied sediment. Finally, multivariate statistics were applied for a better interpretation of results. A factor analysis was developed to establish the relationship among variables and to derive local sediment quality guidelines (SQG) by linking chemical contamination to biological effects. When multidimensional scaling and cluster analysis were performed to group the locations according to either the chemistry or toxicity data, P3-site was always clearly broken up the others. The different approaches all supported the same conclusion: site P3 can be considered highly contaminated by both trace metals and PAHs resulting in high toxicity for all the tested species. 相似文献
49.
Jouni Heikkinen Jouni Vielma Marja Tiirola Tapio Kiuru Atte von Wright 《Aquaculture (Amsterdam, Netherlands)》2006,261(1):259-268
Effects of soybean meal (SBM) based diet on growth performance, histology of the intestinal epithelium and on the gut microbiota of juvenile rainbow trout (Oncorhynchus mykiss) were investigated on two trials lasting for 8 weeks (Trial I) and 18 weeks (Trial II). The microbiological characterization was done both with conventional plating techniques, biochemical profiling and length heterogeneity analysis of PCR amplified 16S rDNA (LH-PCR).Typical histological changes were found after 18 weeks of SBM feeding (Trial II). Mean height of simple foldings were significantly higher within the group fed with fish meal (FM) based diet. These changes were not, however, reflected in the appearance, behavior and weight gain of the fish, although the feed conversion rate (FCR) was higher, compared to fish fed with the traditional FM feed.In both SBM and FM groups the counts of cultivable intestinal bacteria dropped within the first 4 weeks of feeding (Trial I). Subsequently, the bacterial numbers increased in the FM group, but not in the SBM group by the 8th week of the trial. The LH-PCR data suggested also that diet-related qualitative changes in the microbiota had occurred (Trial II). The main identified bacteria were mainly representatives of the genera Aeromonas, Sphingomonas and Chryseomonas, and among the lactic acid bacteria, Lactococcus and Lactobacillus.Future research will be directed to the identification and eventual elimination the SBM-associated factors involved in the inflammatory responses and unfavorable FCR, in particular by modifying the intestinal microbiota. 相似文献
50.
Tuomisto JT Tuomisto J Tainio M Niittynen M Verkasalo P Vartiainen T Kiviranta H Pekkanen J 《Science (New York, N.Y.)》2004,305(5683):476-7; author reply 476-7