ThetaigaconiferousforestsoftheSiberianregionarethemaincarbonsinksintheforestecosystems.Quantitatively,thesizeofthecarbonaccumulationisdeterminedbythephotosyntheticproductivity,whichisstronglyinfluencedbyenvironmentalfactors.Asaresult,anassessmentoftherelationshipbetweenenvironmentalfactorsandphotosyntheticproductivitymakesitpossibletocalculateandevenpredictcarbonsinksinconiferousforestsattheregionallevel.However,atvariousstagesofthevegetativeperiod,theforceoftheconnectionbetweenenvironmentalconditionsandtheproductivityofphotosynthesismaychange.Inthisresearch,correlationsbetweenthephotosyntheticactivityofScotspine(PinussylvestrisL.)withtheenvironmentalconditionswerecomparedinspringandinautumn.Inspring,closepositivecorrelationofthemaximumdailynetphotosynthesiswasidentifiedwithonlyoneenvironmentalfactor.Fordifferentyears,correlationswereforsoiltemperature(rs=0.655,p=0.00315)oravailablesoilwatersupply(rs=0.892,p=0.0068).Inautumnwithindifferentyears,significantcorrelationwasshownwithtwo(temperatureofairandsoil;rs=0.789and0.896,p=0.00045and0.000006,respectively)andfourfactors:temperatureofair(rs=0.749,p=0.00129)andsoil(rs=0.84,p=0.00000),availablesoilwatersupply(rs=0.846,p=0.00013)andirradiance(rs=0.826,p=0.000001).Photosyntheticactivityhasaweakerconnectionwithchangesinenvironmentalfactorsinthespring,ascomparedtoautumn.Thisisexplainedbythemultidirectionalinfluenceofenvironmentalconditionsonphotosynthesisinthisperiodandbythenecessityofearlierphotosynthesisonset,despitetheunfavorableconditions.Thisdatamaybeusefulforpredictingtheflowofcarbonindependenceonenvironmentalfactorsinthisregioninspringandinautumn.
