Agronomijas v stis - Latvijas Lauksaimniecības universitāte

KopsavilkumsBalsoties uz prognozēto meža fonda dinamiku sakarā ar globālajām klimata pārmaiĦām, tika veiktaklimatiski noteikta prognoze galveno savvaĜas ogu sugu resursiem, tai skaitā brūklenēm(Vaccinium vitis-idaea L.), savvaĜas zilenēm (Vaccinium uliginosum L.), Eiropas dzērvenēm(Oxycoccus palustris Pers.) un mellenēm (Vaccinium myrtillus L.) Baltkrievijā līdz 2050. gadam arlaika intervālu 5 gadi. Eiropas dzērveĦu un melleĦu ražas var palielināties, bet brūkleĦu unsavvaĜas zileĦu samazināties aprakstītā perioda gaitā. Kopumā apskatīto svarīgāko meža ogu ražasvarētu palielināties par 11 procentiem.Key words: Vaccinium vitis-idaea L., Vaccinium uliginosum L., Vaccinium myrtillus L.,Oxycoccus palustris Pers., forecast.IntroductionNowadays forecasting is used on all levels of the national economy. Of prime importance is theenvironmental forecast. This is required to plan harmonious exploitation and protection of plantresources on the basis of scientific anticipation of environmental changes.Recent trends in Belarus are towards reorientation of the environmental policy to suit requirementsfor steady development. In this regard, therefore, major problems are those associated withforecasts of environmental changes. The most intricate ecological forecasts are required to foreseechanges in forest plant resources, including wild berry plant resources. In specific cases predictedenvironmental impact assessments may serve to devise scenarios of changes in plant resources indifferent regions of the country.The last few years have witnessed a decline in the resource potential of wild berry plants due to theincreasing scale of society’s impact on the forest ecosystems. Cuttings, reforestation, forest firesare very detrimental to the berry fields. Also, this decline is associated with radioactivecontamination, digression of forest phytocoenoses, drainage reclamation, violation of harvestingregulations and wanton consumption of berries. Management for timber production alone cannotpromote reproduction of minor forest products (Grimashevich, 2002, 2005).Forecasts for minor forest produce resources and their relationship with the dynamics of foreststands might ensure the rational use and protection of side products. A perfect forecast of thedynamics of forest stands, including berry fields, offers a means of carrying out silviculturalpractices to prevent negative trends.We recognise the following forecasts in relation to the forecast duration: seasonal (up to 1 year),short-range (1 to 5 years), extended-range (5 – 15 years), long-range (15 years to several decades)and very-long-range (several hundreds of years) (Loginov, 2004). Forty-two years being left to theyear 2050, our investigation was based on the long-range forecast.Materials and methodsUsing data from forest surveys of all the stands of forest-forming species occurring in Belarus andeach of the state production forestry associations (SPFA) and taking into consideration thegeobotanical subdivision, we systematised the data obtained and analysed the condition andstructures of the stands assayed. Principal parameter values and pre-existing dynamics of resourcesof the berry plants assayed were obtained on the basis of our earlier investigations and regularitiesrevealed in the current research (Grimashevich, 2002, 2005).Estimates of climate changes that may occur in Belarus over the period of the first fifty years of the21 st century were made on the basis of the results obtained through the use of the had CM2atmospheric circulation model (Great Britain). The years 1960 – 1990 were taken as the baseperiod. Climate changes, essential to forestry, according to this model, are a monthly rise inaverage temperature by 0.6 °С to 2.9 °С, a decrease in the transpiration rate and an insignificantincrease of rainfall in winter months when its role as a source of moisture for the current-yearvegetation period is slight (Loginov, 2004).In forecasting changes in the resources of wild berry plants at 5-year intervals we used verified dataobtained by us in the years 2003 – 2004; the data on variations in the typological structure of foreststands obtained by Lazareva (2007) in 2006 – 2007 being used as a basis for the data. Our forecast30